JP5044599B2 - Golf ball core with soft outer transition and negative hardness gradient - Google Patents

Description

  The present invention relates generally to golf balls with a core, and more specifically to golf balls with a single layer core having a surface hardness equal to or less than the center hardness.

  This application is a continuation-in-part of U.S. patent application Ser. No. 12 / 048,665, filed on Mar. 14, 2008, which is a U.S. patent application Ser. No. 11/772, filed on Jul. 3, 2007. This is a partial continuation application of 903.

  Solid golf balls are typically manufactured from a solid core encapsulated by a cover, both the solid core and the cover may have multiple layers, for example, a dual core comprises a solid center and an outer core layer. The multi-layer cover also has an inner layer. In general, golf ball cores and / or centers are constructed from compositions based on thermoset rubber, typically polybutadiene. The core is typically heated and cross-linked to achieve a predetermined property, such as greater or lesser compression, which affects the spin rate and / or better “feel” of the ball. These and other features may be fine-tuned according to the demands of golfers of various skills. From the golf ball manufacturer's point of view, it is desirable for the core to achieve a wide range of properties, such as elasticity, durability, spin, and “feel”. This allows manufacturers to manufacture and sell many different types of golf balls adapted to different levels of workmanship.

  Traditionally, many single-core golf balls have a conventional hardness gradient, from hard to soft, from the surface of the core to the center of the core. The patent literature includes a number of literature that examines the hardness gradient across a golf ball from a hard surface to a soft center.

  U.S. Pat. No. 4,650,193 (Molitor et al., US Pat. No. 5,697,097) treats a curable elastomeric slag with a curing modifier and then molds the slag into a core to form a surface layer of the core. To provide a hardness gradient. This treatment is alleged to provide the core with two regions of different composition, the first part being a hard, resilient, central part of the core, which remains untreated, The part 2 is a soft, easily deformable core outer layer, which has been treated with a core modifier. The two “layers” or regions of the core are integral with each other, resulting in a gradient effect from a soft surface to a hard center.

  U.S. Pat. No. 3,784,209 (Berman et al., U.S. Pat. No. 5,677,097) generally discloses a hardness gradient from soft to hard. The “209” patent discloses a non-uniform molded golf ball using a “mixed” elastomer core. The uncured central sphere is surrounded by a compatible but different uncured elastomer. The two layers of elastomer are simultaneously exposed to the curing agent and become integral with each other, thereby forming a mixed core. The core center is stiffer with a greater density of the first elastomer material than the outer layer. One drawback of this manufacturing method is the time-consuming process of forming the first elastomer, then forming the second elastomer, and then molding the two together. .

  Other patents consider cores that accept surface treatments that achieve a soft “skin”. However, because the inner parts of these cores are untreated, they are accompanied by a gradient from a hard surface to a soft center similar to conventional cores. For example, U.S. Pat. No. 6,113,831 (Nesbitt et al., US Pat. No. 5,677,086) discloses a generally conventional core and a separate soft skin that wraps around the core. This soft skin is formed by exposing the base material slag to the stream during the molding process such that the maximum molding temperature exceeds the stream set temperature, and controlling the exothermic molding temperature during molding. This skin has the outermost 1/32 inch to 1/4 inch in the radial direction of the spherical core. US Pat. Nos. 5,976,443 and 5,733,206 (both Nesbitt et al., Patent Documents 4 and 5) provide water mist on the slag surface to form a soft skin before molding. Is disclosed. Allegedly, water delays cross-linking of the core surface, thereby forming a softer skin around the hard central portion, thereby softening the core compression.

  In addition, many patents disclose multi-layer golf ball cores, where each core layer has a different hardness, thereby creating a hardness gradient from one core layer to another.

However, it is possible to realize a single-layer core with a gradient that becomes softer and harder (“negative” gradient) from the surface to the center, and to realize an inexpensive and efficient method for manufacturing such a core. Still desired. A core having such properties allows golf ball designers to produce products with a unique combination of compression, “feel”, and spin.
US Pat. No. 4,650,193 US Pat. No. 3,784,209 US Pat. No. 6,113,831 US Pat. No. 5,976,443 US Pat. No. 5,733,206

  The present invention is a single core comprising a mass (volume), an outer surface, a geometric center, and an outermost transition (transition volume) adjacent to the outer surface, comprising a substantially uniform composition. A golf ball having a manufactured product and a cover layer, the outermost transition being disposed between the outer surface and the geometric center of the core, the transition having an outer portion that matches the outer surface of the core And having the outermost 45% or less of the core volume, and both the hardness of the outer surface of the core and the hardness in the outermost transition are less than the hardness of the geometric center, forming a negative hardness gradient Is directed to things.

  In a preferred embodiment, the transition is from the outer 5% to 40% of the core volume, more preferably the outermost 10% to 30% of the core volume, most preferably the outermost 10% of the core volume. % To 20%. The thickness of the transition is typically 0.65 mm to 2.5 mm, preferably 0.75 mm to 1.9 mm, more preferably 1 mm to 1.5 mm.

  The hardness of the outer surface of the core is 1 Shore C to 10 Shore C less than the hardness of the geometric center, more preferably 1 Shore C to 5 Shore C less than the hardness of the geometric center. The transition has an inner portion and the hardness in the transition is at least 2 shore C / mm, more preferably at least 3 shore C / mm, most preferably at least 4 shore in a direction away from the inner portion to the outer portion. Decrease at C / mm. The cover layer is preferably made from ionomer, polyurethane, polyurea, polyurethane-urea, or polyurea-urethane.

  The invention also includes a single core having a mass, an outer surface, a geometric center, and an outermost transition adjacent to the outer surface, manufactured from a substantially uniform composition. A golf ball having a cover layer and a single core and an intermediate layer disposed between the cover layers, wherein the outermost transition is disposed between the outer surface of the core and the geometric center. Has an outer portion that coincides with the outer surface of the core, has an outermost 45% or less of the core volume, and both the hardness of the outer surface of the core and the hardness in the outermost transition are geometric centers Is directed to those that form a negative hardness gradient.

  In one embodiment, the intermediate layer is made from an ionomeric material. In other embodiments, the cover layer is preferably made from ionomer, polyurethane, polyurea, polyurethane-urea, or polyurea-urethane.

  The invention further comprises a single inner core having a mass, an outer surface, a geometric center, and an outermost transition adjacent to the outer surface, made from a substantially uniform composition. And an outer core layer with a negative or positive hardness gradient disposed around the single inner core, an inner cover layer, and an outer cover layer having polyurethane, polyurea, or a hybrid thereof. A golf ball, wherein the outermost transition is disposed between the outer surface and the geometric center of the inner core, the transition having an outer portion that conforms to the outer surface of the core, and the outermost volume of the inner core It is directed to those having 45% or less and both the hardness of the outer surface of the inner core and the hardness in the outermost transition are less than the hardness of the geometric center and form a negative hardness gradient. In a preferred embodiment, the inner cover layer is made from an ionomeric material.

  The golf balls of the present invention may include single layer (one-piece) golf balls and multi-layer golf balls, such as golf balls with a core and a cover surrounding the core, but preferably a solid center (also known as the inner core). And a core having an outer core layer, an inner cover layer, and an outer cover layer. Of course, either the core and / or cover layer may include multiple layers. In a preferred embodiment, the core is manufactured from an inner core and an outer core, the inner core and outer core layer being the innermost portion from the outer surface of each element (ie, the center of the inner core or the inner surface of the outer core layer). Although there is a “soft to hard” hardness gradient (“negative” hardness gradient) radially inward, alternative embodiments can be envisaged that change the direction and combination of hardness gradients between core elements. (For example, a “negative” gradient in the center but a “positive” gradient in the outer core layer, or vice versa).

  The center of the core may be a liquid-filled or hollow sphere surrounded by one or more intermediate and / or cover layers, or a solid or liquid wrapped around a tensioned elastic material It may be the center. Any layer disposed around these alternative centers may be accompanied by the hardness gradient (ie, “negative”) of the core of the present invention. The cover layer may be formed from a single layer or, for example, a plurality of layers, specifically an inner cover layer and an outer cover layer.

  As briefly discussed above, in the core of the present invention, the hardness gradient is measured at the surface of the inner core (or outer core layer), and radially to the center of the inner core, typically 2 mm. Defined by hardness measurements made in increments of. As used herein, the terms “negative” and “positive” refer to the innermost portion of the element being measured (eg, the center of the inner core in a solid core or dual core structure; the inner surface of the core layer; other ) Hardness value is subtracted from the hardness value of the outer surface of the element being measured (eg, the outer surface of the solid core; the outer surface of the inner core in the dual core; the outer surface of the outer core layer in the dual core, etc.) Results. For example, if the hardness value of the outer surface of the solid core is less than the center (ie, the surface is softer than the center), the hardness gradient is considered a “negative” gradient (small number−large number = negative number). The core of the present invention preferably has a zero or negative hardness gradient, more preferably between zero (0) and -10, most preferably between 0 and -5.

  More specifically, the present invention provides a soft “skin” (ie transition volume (transition volume) on the outermost surface of the core, eg, the outer surface of a single core, or the outer surface of an outer core layer in a dual core structure. )) Is directed to generate. The skin or transition is not a separate layer but part of a single core with different hardness properties than the rest of the core, all of which are made from the same composition.

  The “skin” is typically formed as a core volume ranging from about 0.001 inches to about 0.100 inches, more preferably from about 0.010 inches to about 0.030 inches from the surface. In the most preferred embodiment, the single or multi-layer core is treated as a matrix by coating the surface of the matrix with a curing modifying material. The cure modifying material may be in the form of a solution, such as a liquid, a dispersion, or a slurry in a solvent. Suitable solvents include but are not limited to water, hydrocarbon solvents, polar solvents, and plasticizers. Water is preferred if a liquid is employed. In the most preferred embodiment, a free-flowing, relatively small particle size powder is employed to uniformly coat the matrix.

  Preferably, the layer is a core or core layer, but in an alternative embodiment it is also a cover or cover layer (inner or outer cover layer) comprising a diene rubber composition, preferably polybutadiene rubber.

  Hardening modifiers for processing include, but are not limited to, antioxidants, sulfur-containing compounds such as pentachlorothiophenol or metal salts thereof, softening acrylate monomers or oligomers, and soft powdered thermoplastics such as , Ethyl vinyl acetate, ethylene butyl acrylate, ethylene methyl acrylate, and a very low modulus ionomer. Preferred cure modifiers include phenolic antioxidants, hydroquinones, and “softening and speeding up” agents (soft and fast agents), such as organic sulfur compounds, inorganic sulfur compounds, and thiophenols, specifically Pentachlorothiophenol (PCTP) and metal salts of PCTP, such as ZnPCTO, MgPCTP, DTDS, and US Pat. Nos. 6,458,895, 6,417,278, and 6,635,716, U.S. Patent Application Publication No. 2006/021586, the contents of which are incorporated herein by reference. Alternatively, thermoplastic or thermosetting powders such as low molecular weight polyethylene, ethylene vinyl acetate, ethylene copolymers and terpolymers (ie NUCREL ™, ethylene butyl acrylate, polyurethanes, polyureas, polyurethane copolymers (ie silicones) Urethane), PEBAX ™, HYTREL ™, polyesters, polyamides, epoxies, silicones, and Micromorph ™ materials, such as US Patent Application Publication Nos. 11 / 690,530 and 11 / 690,391. The contents of this patent document are incorporated herein by reference.

  In one particularly preferred embodiment, a polybutadiene rubber matrix is coated with an antioxidant-containing powder and then molded at a temperature of 350-360 ° F. for 11 minutes to form a single core. The resulting core has a diameter of about 1.580 inches and a geometric center hardness of about 60 Shore C to about 80 Shore C, preferably about 65 Shore C to about 78 Shore C, most preferably about 70. From Shore C to about 75 Shore C. The hardness at a distance of about 8 mm from the center point is about 75 Shore C to about 77 Shore C, about 73 Shore C to about 75 Shore C at 14 mm from the center point, and about 80 Shore C at 18 mm from the center point. Yes, it is about 85 Shore C at 25 mm from the center point, and about 90 Shore C at 30 mm from the center point. The soft “skin” hardness at a point about 31 mm to about 40 mm from the center point of the core is about 60 Shore C to about 80 Shore C, preferably about 65 Shore C to about 75 Shore C, most preferably about 68. Shore C to about 74 Shore C and an overall hardness (center to surface) of zero, most preferably negative (ie about -30 to 0, more preferably about -15 to 0, most preferably about -10 to 0) Measured). Typically, the core in this example has an Atti compression of about 70 and a COR of about 0.800 when measured at an input speed of 125 ft / s. Preferred Atti core compression is 110 or less, preferably 100 or less, more preferably about 90 or less, and most preferably 80 or less.

  A second particularly preferred embodiment is a two-piece core made from an inner core and an outer core layer. Preferably, the outer core layer is processed to form a soft outer “skin”, although the inner core may or may not be “treated” as described herein. In one embodiment, the soft inner core is surrounded by a relatively hard outer core layer. The outer diameter of the inner core is preferably about 1.0 inch, its center point hardness is about 55 Shore C to about 60 Shore C, and its outer surface hardness is about 75 Shore C to about 80 Shore C. is there. The surface hardness of the modified “skin” of the outer core layer is from about 60 Shore C to about 80 Shore C, more preferably from about 65 Shore C to about 75 Shore C, and most preferably from about 68 Shore C to about 74 Shore C. It is. The preferred overall slope is from negative to zero, most preferably negative (ie about -30 to 0, more preferably about -15 to 0, most preferably about -10 to 0).

  Another embodiment is a single core with a mass (volume), an outer surface, a geometric center, and an outermost transition (transition volume) adjacent to the outer surface, with a substantially uniform composition A golf ball having a cover layer and a golf ball manufactured from a product. The outermost transition is disposed between the outer surface of the core and the geometric center, the transition having an outer portion that coincides with the outer surface of the core and having an outermost 45% or less of the core volume. In addition, both the hardness of the outer surface of the core and the hardness in the outermost transition portion are smaller than the hardness of the geometric center, forming a negative hardness gradient.

  The transition portion comprises the outermost 5% to 40% of the core volume, more preferably the outermost 10% to 30% of the core volume, and most preferably the outermost 10% to 20% of the core volume. Have. The thickness of the transition is typically 0.65 mm to 2.5 mm, preferably 0.75 mm to 1.9 mm, more preferably 1 mm to 1.5 mm.

The hardness of the outer surface of the core is 1 Shore C to 10 Shore C less than the hardness of the geometric center, more preferably 1 Shore C to 5 Shore C less than the hardness of the geometric center. The transition has an inner portion and the hardness in the transition is at least 2 shore C / mm, more preferably at least 3 shore C / mm, most preferably at least 4 shore in a direction away from the inner portion to the outer portion. Decrease at C / mm. The cover layer is preferably made from ionomer, polyurethane, polyurea, polyurethane-urea, or polyurea-urethane.

  An alternative embodiment is a single core having a mass, an outer surface, a geometric center, and an outermost transition adjacent to the outer surface, made from a substantially uniform composition And a cover layer and a single core and an intermediate layer disposed between the cover layer. The outermost transition is disposed between the outer surface of the core and the geometric center, the transition having an outer portion that coincides with the outer surface of the core, and the outermost 45% or less of the core volume. And both the hardness of the outer surface of the core and the hardness in the outermost transition part are smaller than the hardness of the geometric center and form a negative hardness gradient. The intermediate layer is made from an ionomeric material. In other embodiments, the cover layer is made from an ionomer, polyurethane, polyurea, polyurethane-urea, or a hybrid thereof.

  An example of a dual core is a single inner core with a mass, an outer surface, a geometric center, and an outermost transition adjacent to the outer surface, made from a substantially uniform composition. An outer core layer with a negative or positive hardness gradient disposed around the single inner core, an inner cover layer, and an outer cover layer having polyurethane, polyurea, or a hybrid thereof. Including a golf ball. The outermost transition is disposed between the outer surface of the inner core and the geometric center, the transition having an outer portion that coincides with the outer surface of the core, and the outermost 45% or less of the inner core volume. And both the hardness of the outer surface of the inner core and the hardness in the outermost transition part are smaller than the hardness of the geometric center and form a negative hardness gradient. Preferably, the inner cover layer is made from an ionomeric material.

  The core formulation used in this invention is cobalt-, nickel-, lithium-, or neodymium-catalyzed, most preferably Co-, or Nd-catalyzed and has a Mooney viscosity of about 25 to about 125, High cis polybutadiene rubber, preferably from about 30 to about 100, most preferably from about 40 to about 60, is preferably based. A smaller amount of non-polybutadiene rubber, such as styrene butadiene rubber, trans-polyisoprene, natural rubber, butyl rubber, ethylene propylene rubber, ethylene propylene diene monomer rubber, low cis polybutadiene rubber, or trans polybutadiene rubber is blended into polybutadiene rubber. Good. Coagents such as zinc diacrylate or zinc dimethacrylate are typically present at levels of from about 0 pph to about 60 pph, more preferably from about 10 pph to about 55 pph, and most preferably from about 15 pph to about 40 pph. Peroxides or peroxide blends are also typically present in an amount from about 0.1 pph to about 5.0 pph, more preferably from about 0.5 pph to about 3.0 pph. Zinc oxide may also be present from about 5 pph to about 50 pph, and the antioxidant is also present from about 0 pph, from about 0.1 pph to about 5.0 pph, more preferably from about 0.5 pph to about 3.0 pph.

  Other embodiments include any number of core layers and gradient combinations in which the surface of at least one layer of the core is “treated” as described above.

  Scrap automobile tire regrinds (fine powder form) are also uncrosslinked or partially crosslinked, so that the soft outer “of the invention” as well as other powdered rubbers capable of reacting with polybutadiene. It is enough to form the “skin”. A fully crosslinked rubber still adheres well with the polybutadiene substrate (although the reaction is minimal) and forms a sufficiently good bond.

  Other potential surface softening or cure modifiers include, but are not limited to, sulfated fats, sodium salts, alkylated aromatic sulfonic acids, substituted benzoid alkyl sulfonic acids, diethylene glycol and dipropylene glycol Monoaryl and alkyl ethers, ammonium salts of alkyl phosphates, sodium alkyl sulfates, monosodium salts of methyl oleate sulfate, sodium salts of carboxylated electrolytes. Other suitable materials are dithiocarbamates such as zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc diamyldithiocarbamate, tellurium diethyldithiocarbamate, selenium dimethyldithiocarbamate, selenium diethyl Dithiocarbamate, lead diamyldithiocarbamate, bismuth dimethyldithiocarbamate, cadmium diethyldithiocarbamate, and mixtures thereof.

  The method of manufacturing a golf ball of the present invention includes various steps and options. Typically, a polybutadiene rubber composition is mixed using a Banbury type mixer or the like. The rubber composition is extruded as an extrudate and cut into a predetermined shape, for example, a cylindrical shape, which is typically called a “base material” (preform). The matrix with the uncured polybutadiene composition is then pre-processed for coating with at least one cure modifier (liquid), liquid, solvent, which was described above. Preferred cure modifiers here include antioxidants, sulfur-containing compounds, zinc methacrylate, zinc dimethacrylate, softening acrylate monomers or oligomers, soft powdered thermoplastics, phenol-containing antioxidants, or hydroquinone. And most preferably has an antioxidant.

  In one embodiment, two or more cure modifiers are used in succession. In this example, a preferred combination includes a second cure modifier such as an antioxidant or peroxide that is different from the first cure modifier such as an antioxidant. Compatibilizers and / or tie layers may be incorporated. Further, a two-stage dipping or roll (in the curing correction material) may be employed to sequentially supply the first and second antioxidants, or antioxidant and peroxide.

  Optionally, prior to coating the base material, the uncured base material may be shaped into a rough sphere or molded at room temperature. The coating may be performed in various ways, including but not limited to rolling, spraying, dipping, or dusting. The coating may be uniform or non-uniform, but is preferably uniform.

The uncured, uncoated base material may optionally be heated to a predetermined temperature for a predetermined time, which is substantially lower than the predetermined curing temperature, thereby providing a curing modifying material. Can be diffused, penetrated, moved, etc. into the matrix, or moved to move into the matrix, or alternatively any solvent can be evaporated or the matrix can be dried (the coating should be in liquid form). If so). If two cure modifiers are employed, this time is desirable to allow any reaction that takes place to complete.

  The uncured coated base material is then cured and molded at a predetermined temperature and time to produce a crosslinked golf ball core. As detailed above, in this core, the outer surface has a first hardness and the geometric center has a second hardness greater than the first hardness, forming a “negative” hardness gradient. Any of the plurality of cover layers may be formed around a “negative” gradient core, including, but not limited to, an outer core layer, an inner cover layer, and an outer cover layer.

  The cured core is then typically coreless polished so that the core becomes a uniform sphere, and its surface is roughened and textured to make subsequent layers easier to adhere. Before or after coreless polishing, the core may be treated with plasma discharge, corona discharge, silane, or chlorination, which facilitates, for example, adhesive properties.

  Particularly preferred methods include a step of extruding the polybutadiene composition to form a cylindrical extrudate, a step of cutting the extrudate to form an uncured polybutadiene matrix, and a cure modifying material having a first antioxidant. Coating the base material uniformly, curing the coated base material to provide an outer surface with a first hardness and a geometric center with a second hardness greater than the first hardness and negative Forming a cross-linked core that achieves a hardness gradient, coreless polishing the hardened core to form a uniform spherical core with increased surface roughness, uniform inner cover layer Forming a spherical core and forming an outer cover layer around the inner cover layer to produce a golf ball.

  Preferably, the core layer (inner core or outer core layer) is made from a composition comprising at least one thermoset base rubber, for example polybutadiene rubber, which comprises at least one peroxide and at least one reactive. Cured with a coagent, which may be an unsaturated carboxylic acid, such as a metal salt of acrylic or methacrylic acid, a non-metallic coagent, or a mixture thereof. Preferably, a suitable antioxidant is included in the composition. Optional softening and accelerating agents (and often cis-to-trans catalysts), such as organic sulfur or metal-containing organic sulfur or rods, may also be included in the core formulation.

  Other ingredients known to those skilled in the art may be used, including but not limited to density adjusting fillers, processing aids, plasticizers, blowing agents or foaming agents, sulfur accelerators, and / or non-peroxidation. It can be understood to include a radical source.

  The base thermoset rubber may be blended with other rubbers and polymers and typically includes natural rubber or synthetic rubber. A preferred base rubber is 1,4-polybutadiene with a cis structure of at least 40%, preferably more than 80%, more preferably more than 90%.

  Examples of desired polybutadiene rubbers include BUNA ™ CB22 and BUNA ™ CB23, commercially available from LANXESS; UBEPOL ™ 360L, commercially available from UBE Industry, Tokyo, Japan; UBEPOL ™ 150L and UBEPOL-BR rubber; KINEX ™ 7245 available from Goodyear, Akron, Ohio; SE BR-1220 and TAKTENE ™ 1203G1,220 commercially available from Dow Chemical, And 221; Europrene ™ NEOCIS ™ BR40 and BR60, commercially available from Polymeri Europa; and Japan Synthetic Rubber BR 01 commercially available, BR 730, BR 11, and BR 51; PETROFLEX (TM) BRNd-40; and Karbochem Inc. from commercially available KABOCHEM (TM) ND40, ND45, and a ND60.

  The base rubber may have a Mooney viscosity high or medium rubber, or a blend thereof. The “Mooney” unit refers to the unit employed to measure the plasticity of raw or unvulcanized rubber. The Mooney unit plasticity is equal to the torque applied to the disk in a container that rotates at a rate of 2 revolutions per minute, including rubber at a temperature of 100 ° C., measured at any scale. The measurement of Mooney viscosity is specified in ASTM D-1646.

  The range of Mooney viscosity is preferably greater than about 40, more preferably in the range of about 40 to about 80, and even more preferably in the range of about 40 to about 60. Polybutadiene rubber having a higher Mooney viscosity may be used. However, it is a condition that the viscosity of the polybutadiene does not reach a level at which the high viscosity polybutadiene is clogged or otherwise adversely affects the production machine. It can be understood that polybutadiene having a viscosity of less than 65 Mooney can be used in the present invention.

  In one embodiment of the present invention, a golf ball core made from a medium to high Mooney viscosity polybutadiene material achieves great resilience (and thus a large distance) without increasing the hardness of the ball. Such cores are soft, i.e., compression is less than about 60, more specifically in the range of about 50-55. Cores with compression in the range of about 30 to about 50 are also within the scope of such preferred embodiments.

  Suitable medium or high Mooney viscosity polybutadiene commercial resources include Bayer AG CB23 (Nd catalyst) and Shell 1220 (cocatalyst), the former with Mooney viscosity around 50 and linear vegetable polybutadiene in hardness. It is. When desired, the polybutadiene may be mixed with other elastomers known in the art, such as other polybutadiene rubber, natural rubber, styrene butadiene rubber, and / or isoprene rubber to modify the properties of the core. When using a mixture of elastomers, the amount of other components in the core composition is typically based on 100 parts by weight of the total amount of the elastomer mixture.

  In one embodiment, the base rubber comprises Nd catalyzed polybutadiene, rare earth catalyzed polybutadiene rubber, or a blend thereof. When desired, the polybutadiene may be mixed with other elastomers known in the art, such as natural rubber, polyisoprene rubber, and / or styrene butadiene rubber to modify the properties of the core. Other suitable base rubbers include thermosetting materials such as ethylene propylene diene monomer rubber, ethylene propylene rubber, butyl rubber, halobutyl rubber, hydrogenated nitrile butadiene rubber, nitrile rubber, and silicone rubber.

  A thermoplastic elastomer (TPE) may be mixed with a base thermoset rubber to modify the properties of the core layer or uncured core layer stock. These PTEs are natural or synthetic rubbers, or high trans-polyisoprene, high trans-polybutadiene, or any styrene block copolymer, such as styrene ethylene butadiene styrene, styrene-isoprene-styrene, metallocene or other single site catalyzed polyolefins For example, styrene-octene, or ethylene-butene, or thermoplastic polyurethane (TPU), which includes, for example, copolymers with silicone. Other TPEs suitable for mixing with the thermoset rubbers of this invention are considered to have polyetheramide copolymers, PEBAX ™, polyetherester copolymers, HYTEL ™, which are believed to have thermoplastic urethanes. ), And KRATON ™, which is believed to have a styrene block copolymer elastomer. Any of the TPEs or TPUs described above contain functional groups suitable for grafting and include maleic acid or maleic anhydride.

  Additional polymers may optionally be incorporated into the base rubber. Examples of such include, but are not limited to, thermosetting elastomers such as core liglins, thermoplastic vulcanizates, copolymeric ionomers, terpolymeric ionomers, polycarbonates, polyamides, copolymeric polyamides, polyesters, polyvinyl alcohol, acrylonitrile-butadiene- Styrene copolymer, polyarylate, polyacrylate, polyphenylene ether, impact modified polyphenylene ether, high impact polystyrene, diallyl phthalate polymer, styrene-acrylonitrile polymer (SAN) (including olefin modified SAN and acrylonitrile-styrene-acrylonitrile polymer) , Styrene-maleic anhydride copolymer, styrene copolymer, functional styrene copolymer, functional styrene terpoly Chromatography, styrene terpolymers, cellulose polymers, liquid crystal polymers, ethylene - vinyl acetate copolymer, polyurea and polysiloxane or these species metallocene-catalyzed polymers.

  Polyamides suitable for use as an additional polymeric material for compositions within the scope of this invention include resins obtained as follows. (1) As (a) dicarboxylic acid such as succinic acid, adipic acid, sebacic acid, terephthalic acid, isophthalic acid, or 1,4-cyclohexanedicarboxylic acid, (b) diamine such as ethylenediamine, tetraethylenediamine, pentamethylenediamine, hexamethylene Polymerization is carried out with diamine, decamethylenediamine, 1,4-cyclohexylamine or m-xylylenediamine. As (2), ring-opening polymerization of a cyclic lactam such as epsilon caprolactam or omega laurolactam is performed. As (3), an aminocarboxylic acid such as 6-aminocaproic acid, 9-aminocaproic acid, 11-aminocaproic acid or 12-aminocaproic acid is polymerized. Alternatively, as (4), a cyclic lactam is copolymerized with a dicarboxylic acid and a diamine. Specific examples of suitable polyamides are NYLON6, NYLON66, NYLON610, NYLON11, NYLON12, copolymers NYLON, NYLONMXD6 and NYLON46.

  Suitable peroxide initiators are dicumyl peroxide; 2,5-dimethyl-2,5-di (t-butylperoxy) hexane; 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne 2,5-dimethyl-2,5-di (benzoylperoxy) hexane; 2,2'-bis (t-butylperoxy) -di-iso-propylbenzene; 1,1-bis (t-butylperoxy)- 3,3,5-trimethylcyclohexane; n-butyl-4,4-bis (t-butylperoxy) valerate; t-butylperbenzoate; benzoyl peroxide; n-butyl-4,4′-bis (butylperoxy) valerate Di-t-butyl peroxide; or 2,5-di- (t-butylperoxy) -2,5-dimethylhexane, lauryl peroxide; - including - (peroxy isopropyl 2-t-butyl) benzene, di -t- butyl peroxide butyl hydroperoxide, alpha-alpha-bis (t-butylperoxy) di-isopropyl propyl benzene, di. Preferably, the rubber composition comprises from about 0.25 to about 5.0 parts by weight (phr) of peroxide, more preferably from 0.5 phr to 3 phr, and most preferably from 0.1 to 100 parts by weight of rubber. Contains 5 phr to 1.5 phr peroxide. In the most preferred embodiment, the peroxide is present in an amount of about 0.8 phr. These ranges of peroxide are given under the assumption that the peroxide is 100% active and does not take into account any carriers that may be present. Since many commercially available peroxides are sold with a carrier compound, the actual abundance of active peroxide must be calculated. Commercially available peroxide initiators include dicumyl peroxide (DICUP ™ R, DICUP ™ 40C and DICUP ™ 40KE) of the DICUP ™ family available from Cropton (Geo Specialty Chemicals). )including. Similar initiators are described in AcroChem, Luxess, Flexsys / Haewick, and R.C. T.A. Available from Vanderbilt. Another commercially available and preferred initiator is TRIGONOX ™ 265-50B from Akzo Nobel, which is 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, and Di (2-t-butylperoxyisopropyl) benzene. TRIPONOX ™ peroxide is sold with a carrier compound.

  Suitable reactive coagents include, but are not limited to, metal salts of diacrylates, dimethacrylates, and monomethacrylates, suitable for use in the present invention are metals that are zinc, manganese, calcium, barium, Those that are tin, aluminum, lithium, sodium, potassium, iron, zirconium, and bismuth. Although zinc diacrylate (ZDA) is preferred, the invention is not so limited. ZDA imparts a large initial velocity to the golf ball. DZA can be of various purity grades. In order to realize the object of the present invention, the ZDA purity increases as the amount of zinc stearate present in the ZDA is small. ZDA containing less than about 10% zinc stearate is preferred. Further preferred is ZDA containing only about 4-8% zinc stearate. Suitable commercially available zinc diacrylates include those available from Sartmer. Preferred concentrations of ZDA available are from about 10 phr to about 40 phr, more preferably from about 20 phr to about 35 phr, and most preferably from about 25 phr to about 35 phr. In a specific preferred embodiment, the reactive coagent is present in an amount from about 29 phr to about 31 phr.

  Additional preferred coagents that may be utilized alone or in combination with those described above include, but are not limited to, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, and others. Those skilled in the art will appreciate that when the coagent is a liquid at room temperature, advantageously, these compounds can be dispersed on a suitable carrier for easier integration into the rubber mixture. .

  Antioxidants are compounds that prevent oxidative breakdown of elastomers and / or prevent reactions promoted by oxygen radicals. Some exemplary antioxidants that can be utilized in this invention include, but are not limited to, quinoline-type antioxidants, amine-type antioxidants, and phenol-type antioxidants. Preferred antioxidants are R.I. T.A. 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol) available as VANOX ™ MBPC from Vanderbilt. Other polyphenolic antioxidants include VANOX (TM) T, VANOX (TM) L, VANOX (TM) SKT, VANOX (TM) SWP, VANOX (TM) 13, and VANOX (TM) 1290.

  Suitable antioxidants include, but are not limited to, alkylene-bis-alkyl substituted cresols such as 4,4′-methylene-bis (2,5-xylenol); 4,4′-ethylidene-bis- (6- 4,4′-butylidene-bis- (6-tert-butyl-m-cresol); 4,4′-decylidene-bis- (6-methyl-m-cresol); '-Methylene-bis- (2-amyl-m-cresol); 4,4'-propylidene-bis- (5-hexyl-m-cresol); 3,3'-decylidene-bis- (5-ethyl-p -Cresol); 2,2'-butylidene-bis- (3-n-hexyl-p-cresol); 4,4 '-(2-butylidene) -bis- (6-t-butyl-m-cresol); 3,3'-4 (Deciride ) -Bis- (5-ethyl-p-cresol); (2,5-dimethyl-4-hydroxyphenyl) (2-hydroxy-3,5-dimethylphenyl) methane; (2-methyl-4-hydroxy-5) -Ethylphenyl) (2-ethyl-3-hydroxy-5-methylphenyl) methane; (3-methyl-5-hydroxy-6-t-butylphenyl) (2-hydroxy-4-methyl-5-decylphenyl) (2-hydroxy-4-ethyl-5-methylphenyl) (2-decyl-3-hydroxy-4-methylphenyl) butylamylmethane; (3-ethyl-4-methyl-5-hydroxyphenyl) )-(2,3-dimethyl-3-hydroxy-phenyl) nonylmethane; (3-methyl-2-hydroxy-6-ethylphenyl)-(2-isopropyl Le-3-hydroxy-5-methyl - phenyl) cyclohexyl methane; (2-methyl-4-hydroxy-5-methylphenyl) (2-hydroxy-3-methyl-5-ethylphenyl) dicyclohexylmethane; others.

  Other suitable antioxidants include, but are not limited to, substituted phenols such as 2-tert-butyl-4-methoxyphenol; 3-tert-butyl-4-methoxyphenol; 3-tert-octyl-4- 2-methyl-4-methoxyphenol; 2-stearyl-4-n-butoxyphenol; 3-tert-butyl-4-stearyloxyphenol; 3-lauryl-4-ethoxyphenol; 2,5-di- t-butyl-4-methoxyphenol; 2-methyl-4-methoxyphenol; 2- (1-methylcyclohexyl) -4-methoxyphenol; 2-t-butyl-4-dodecyloxyphenol; 2- (1-methyl Benzyl) -4-methoxyphenol; 2-t-octyl-4-methoxyphenol; methyl gallate; N-butyl gallate; lauryl gallate; myristyl gallate; stearyl gallate; 2,4,5-trihydroxyacetophenol; 2,4,5-trihydroxy-n-butyrophenol; 2,6-ditert-butyl-4-methylphenol; 2,6-ditert-octyl-4-methylphenol; 2,6-ditert-butyl-4-stearylphenol; 2-methyl-4 -Methyl-6-tert-butylphenol; 2,6-distearyl-4-methylphenol; 2,6-dilauryl-4-methylphenol; 2,6-di (n-octyl) -4-methylphenol; 6-di (n-hexadecyl) -4-methylphenol; 2,6-di (1-methylundecyl) 2,6-di (1-methylheptadecyl) -4-methylphenol; 2,6-di (trimethylhexyl) -4-methylphenol; 2,6-di (1,1,3 , 3-tetramethyloctyl) -4-methylphenol; 2-n-dodecyl-6-tertbutyl-4-methylphenol; 2-n-dodecyl-6- (1-methylundecyl) -4-methylphenol; 2 -N-dodecyl-6- (1,1,3,3-tetramethyloctyl) -4-methylphenol; 2-n-dodecyl-6-n-octadecyl-4-methylphenol; 2-n-dodecyl-6 -N-octyl-4-methylphenol; 2-methyl-6-n-octadecyl-4-methylphenol; 2-n-dodecyl-6- (1-methylheptadecyl) -4-methylphenol 2,6-di (1-methylbenzyl) -4-methylphenol; 2,6-di (1-methylcyclohexyl) -4-methylphenol; 2,6- (1-methylcyclohexyl) -4-methyl Phenol; 2- (1-methylbenzyl) -4-methylphenol; and related substituted phenols.

  More suitable antioxidants include, but are not limited to, alkylene bisphenols such as 4,4′-butylidene bis (3-methyl-6-tert-butylphenol); 2,2-butylidene bis (4,6-dimethylphenol). 2,2'-butylidenebis (4-methyl-6-t-butylphenol); 2,2'-butylidenebis (4-t-butyl-6-methylphenol); 2,2'-ethylidenebis (4-methyl-); 6-t-butylphenol); 2,2'-methylidenebis (4,6-dimethylphenol); 2,2'-methylenebis (4-methyl-6-t-butylphenol); 2,2'-methylenebis (4-ethyl) -6-tert-butylphenol); 4,4'-methylenebis (2,6-di-tert-butylphenol); 4,4'-ethylenebis ( -Methyl-6-t-butylphenol); 4,4'-methylenebis (2,6-dimethylphenol); 2,2'-methylenebis (4-t-butyl-6-phenylphenol); 2,2'-dihydroxy 3,3 ′, 5,5′-tetramethylstilbene; 2,2′-isopropylidenebis (4-methyl-6-tert-butylphenol); ethylenebis (beta-naphthol); 1,5-hydroxynaphthalene; 2,4'-ethylenebis (4-methyl-6-propylphenol); 4,4'-methylenebis (2-propyl-6-tert-butylphenol); 4,4'-ethylenebis (2-methyl-6-) Propylphenol); 2,2′-methylenebis (5-methyl-6-tert-butylphenol); and 4,4′-butylidenebis (6-tert-butyl) 3, including the methyl phenol).

  Suitable antioxidants further include, but are not limited to, alkylene triphenols such as 2,6-bis (2′-hydroxy-3′-tert-butyl-5′-methylbenzyl) -4-methylphenol. 2,6-bis (2′-hydroxy-3′-t-ethyl-5′-butylbenzyl) -4-methylphenol; and 2,6-bis (2′-hydroxy-3′-t-butyl-); 5'-mepropylbenzyl) -4-methylphenol.

  The antioxidant is typically present in an amount from about 0.1 phr to about 5 phr, preferably from about 0.1 phr to about 2 phr, more preferably from about 0.1 phr to about 1 phr. In a specific preferred embodiment, the antioxidant is present in an amount of about 0.4 phr.

  In an alternative embodiment, the antioxidant must be present in an amount that ensures that the hardness gradient of the core of the invention is negative. Preferably, the antioxidant is about 0.2 phr to about 1 phr, more preferably about 0.3 phr to about 0.8 phr, and most preferably about 0.4 phr to about 0.7 phr, core layer (inner core or outer Added to the preparation of the core layer). Preferably, when calculated as 100% activity, about 0.25 phr to about 1.5 phr of peroxide may be added to the core formulation, more preferably about 0.5 phr to about 1.2 phr, most preferably Preferably about 0.7 phr to about 1.0 phr may be added. The amount of ZDA may be varied to suit the desired compression, spinning and feeling of the manufactured bullball. Curing curing involves a temperature range of about 290 ° F (143 ° C) to about 335 ° F (168 ° C), more preferably about 300 ° F (149 ° C) to about 325 ° F (163 ° C). The stock is held at that temperature for at least about 10 minutes to about 30 minutes.

  The thermosetting composition of the present invention may contain an optional softening / fastening agent. As used herein, a “soft and fast agent” makes the core 1) softer under a certain COR than when prepared without a softening and speeding agent. (Small compression) or 2) Any compound or blend thereof, or any combination that causes a greater COR with equal compression. Preferably, the composition of this invention contains from about 0.05 phr to about 10.0 phr of a softening and speeding agent. In one embodiment, the softening and speeding agent is present in the range of about 0.05 phr to about 3.0 pr, preferably about 0.05 phr to about 2.0 phr, more preferably about 0.05 phr to about 1.0 phr. To do. In another embodiment, the softening and speeding agent ranges from about 2.0 phr to about 5.0 pr, preferably from about 2.35 phr to about 4.0 phr, more preferably from about 2.35 phr to about 3.0 phr. Exists. In an alternative high concentration embodiment, the softening and speeding agent is from about 5.0 phr to about 10.0 pr, more preferably from about 6.0 phr to about 9.0 phr, and most preferably from about 7.0 phr to about 8 phr. It exists in the range of 0.0 phr. In the most preferred embodiment, the softening and speeding agent is present in an amount of about 2.6 phr.

  Suitable softening and speeding agents include, but are not limited to, organic sulfur or metal-containing organic sulfur compounds, inorganic sulfur compounds, Group VIA compounds, or mixtures thereof, where the organic sulfur compounds are mono-, di- And polysulfides, thiols, or mercapto compounds. The softening / accelerator compound may be a blend of an organic sulfur compound and an inorganic sulfur compound.

Suitable softening / acceleration agents of this invention include, but are not limited to, those having the following general formula:

In the formula, R _{1 to} R ₅ may be in any order, and may be a C _{1 to} C ₈ alkyl group; a halogen group; a thiol group (—SH), a carboxylate group; a sulfonate group; and hydrogen. 2-fluorothiophenol; 3-fluorothiophenol; 4-fluorothiophenol; 2,3-fluorothiophenol; 2,4-fluorothiophenol; 3,4-fluorothiophenol; 3,3,4-fluorothiophenol; 3,3,4-fluorothiophenol; 2,3,4,5-tetrafluorothiophenol; 2,3,5,6-tetra 4-chlorotetrafluorothiophenol; pentachlorothiophenol; 2-chlorothiopheno 3-chlorothiophenol; 4-chlorothiophenol; 2,3-chlorothiophenol; 2,4-chlorothiophenol; 3,4-chlorothiophenol; 3,5-chlorothiophenol; 4-chlorothiophenol; 3,4,5-chlorothiophenol; 2,3,4,5-tetrachlorothiophenol; 2,3,5,6-tetrachlorothiophenol; pentabromothiophenol; 2-bromo 3-bromothiophenol; 4-bromothiophenol; 2,3-bromothiophenol; 2,4-bromothiophenol; 3,4-bromothiophenol; 3,5-bromothiophenol; , 4-bromothiophenol; 3,4,5-bromothiophenol; 2,3,4,5-tetrabromothiopheno 2,3,5,6-tetrabromothiophenol; pentaiodothiophenol; 2-iodothiophenol; 3-iodothiophenol; 4-iodothiophenol; 2,3-iodothiophenol; 3,4-iodothiophenol; 3,5-iodothiophenol; 2,3,4-iodothiophenol; 3,4,5-iodothiophenol; 2,3,4,5-tetraiodo It may be thiophenol; 2,3,5,6-tetraiodothiophenol; and zinc salts thereof. Preferably the halogenated organic sulfur compound is pentachlorothiophenol, which is commercially available in pure form, or added 45 percent of pentachlorothiophenol (equivalent to 2.4 parts of PCTP). It is available under the trade name STRUKTOL®, a clay-based carrier containing sulfur compounds. STRUKTOL ™ is commercially available from StruktolCompanyof America, Stow, Ohio. PCTP is commercially available in pure form from eChinachem, San Francisco, California, and is available in salt form from eChinachem, San Francisco. Most preferably, the halogenated organic sulfur compound is a zinc salt of pentachlorothiophenol, which is commercially available from eChinachem, San Francisco.

As used herein in reference to the present invention, the term “organo sulfur compound” refers to any compound containing carbon, hydrogen and sulfur, where the sulfur is directly on at least one carbon. To join. As used herein, the term “sulfur compound” means a compound that is elemental sulfur, polymeric sulfur, or a combination thereof. Further, it should be understood that “elemental sulfur” refers to a ring structure of S ₈ and “polymeric sulfur” is a structure that includes at least one additional sulfur relative to elemental sulfur.

  Additional suitable examples of softening and accelerating agents (which may also be considered cis-trans catalysts) include, but are not limited to, diphenyl disulfide; 4,4′-ditolyl disulfide; 2,2′-benzamide Diphenyl disulfide; bis (2-aminophenyl) disulfide; bis (4-aminophenyl) disulfide; bis (3-aminophenyl) disulfide; 2,2′-bis (4-aminonaphthyl) disulfide; (3-aminonaphthyl) disulfide; 2,2′-bis (4-aminonaphthyl) disulfide; 2,2′-bis (5-aminonaphthyl) disulfide; 2,2′-bis (6-aminonaphthyl) disulfide; 2,2′-bis (7-aminonaphthyl) disulfide; 2,2′-bis (8-aminonaphthyl) dis 1,1'-bis (2-aminonaphthyl) disulfide; 1,1'-bis (3-aminonaphthyl) disulfide; 1,1'-bis (3-aminonaphthyl) disulfide; 1,1'-bis (4-aminonaphthyl) disulfide; 1,1′-bis (5-aminonaphthyl) disulfide; 1,1′-bis (6-aminonaphthyl) disulfide; 1,1′-bis (7-aminonaphthyl) disulfide; 1,1′-bis (8-aminonaphthyl) disulfide; 1,2′-diamino-1,2′-dithiodinaphthalene; 2,3′-diamino-1,2′-dithiodinaphthalene; bis (4- Chlorophenyl) disulfide; bis (2-chlorophenyl) disulfide; bis (3-chlorophenyl) disulfide; bis (4-bromophenyl) disulfide Bis (2-bromophenyl) disulfide; bis (3-bromophenyl) disulfide; bis (4-fluorophenyl) disulfide; bis (4-iodophenyl) disulfide; bis (2,5-dichlorophenyl) disulfide; 3,5-dichlorophenyl) disulfide; bis (2,4-dichlorophenyl) disulfide; bis (2,6-dichlorophenyl) disulfide; bis (2,5-dibromophenyl) disulfide; bis (3,5-dibromophenyl) disulfide; Bis (2-chloro-5-bromophenyl) disulfide; bis (2,4,6-trichlorophenyl) disulfide; bis (2,3,4,5,6-pentachlorophenyl) disulfide; bis (4-cyanophenyl) Disulfide; bis (2-cyano Bis (4-nitrophenyl) disulfide; bis (2-nitrophenyl) disulfide; 2,2'-dithiobenzoic ethyl; 2,2'-dithiobenzoic methyl; 2,2'-dithiobenzoic acid 4,4'-dithiobenzoic ethyl; bis (4-acetylphenyl) disulfide; bis (2-acetylphenyl) disulfide; bis (4-formylphenyl) disulfide; bis (4-carbamoylphenyl) disulfide; '-Dinaphthyl disulfide; 2,2'-dinaphthyl disulfide; 1,2'-dinaphthyl disulfide; 2,2'-bis (1-chlorodinaphthyl) disulfide; 2,2'-bis (1-bromonaphthyl) ) Disulfide; 1,1′-bis (2-chloronaphthyl) disulfide; 2 2'-bis (1-cyanonaphthyl) disulfide; 2,2'-bis (1-acetyl-naphthyl) such as disulfide, or mixtures thereof is. Preferred organic sulfur compounds are diphenyl disulfide, 4,4'-ditolyl disulfide, or 2,2'-benzamide diphenyl disulfide, or mixtures thereof. A more preferred organic sulfur compound is 4,4'-ditolyl disulfide. In other embodiments, metal-containing organosulfur compounds may be used in accordance with the present invention. Suitable metal-containing organosulfur compounds are, but are not limited to, cadmium, copper, lead, and tellurium analogs of diethyldithiocarbamate, diamyldithiocarbamate, and dimethyldithiocarbamate, or mixtures thereof.

Suitable substituted or unsubstituted aromatic organic components that do not contain sulfur or metals include, but are not limited to, 4,4′-diphenylacetylene, azobenzene, or mixtures thereof. The aromatic organic group is preferably in the range of C _{6 to} C ₂₀ and more preferably in the range of C _{6 to} C _{10 in} size. Suitable inorganic sulfide components include, but are not limited to, titanium sulfide, manganese sulfide, and similar sulfides of iron, calcium, cobalt, molybdenum, tungsten, copper, selenium, yttrium, zinc, tin, and bismuth. Not.

Substituted or unsubstituted aromatic organic compounds are also softening / accelerating agents. Suitable substituted or unsubstituted aromatic organic components include, but are not limited to, components having the formula (R ₁ ) _x —R ₃ —M—R ₄ — (R ₂ ) _y , where R ₁ and R ₂ are each hydrogen, or substituted or unsubstituted C _{1 to} C ₂₀ linear, branched or cyclic alkyl, alkoxy or alkylthio groups, or monocyclic, polycyclic or condensed ring C ₆ to be a C ₂₄ aromatic radical; x and y are each an integer of 0 to 5; _{R 3} and _{R 4} are each a monocyclic, from _C 6 _{-C 24} aromatic group polycyclic or fused Selected; M is an azo group or a metal component. R ₃ and R ₄ are each preferably selected from C _{6 to} C ₁₀ aromatic groups, more preferably selected from phenyl, benzyl, naphthyl, benzamide and benzothiazyl. R ₁ and R ₂ are each preferably selected from substituted or unsubstituted C ₁ -C ₁₀ linear, branched or cyclic alkyl, alkoxy or alkylthio groups, or C ₆ -C ₁₀ aromatic groups . When R ₁ , R ₂ , R ₃ or R ₄ is substituted, the substituent may include one or more of the following substituents: hydroxy and its metal salt; mercapto and its metal salt; halogen; Amino, nitro, cyano and amide; carboxyls including esters, acids and metal salts thereof; silyl; acrylates and metal salts thereof; sulfonyl or sulfonamides; and phosphates and phosphites. When M is a metal component, M can be any suitable elemental metal available to those skilled in the art. Typically, the metal is a transition metal, but is preferably tellurium or selenium. It can be included in the cis-trans-conversion catalyst. In one embodiment, the aromatic organic compound is substantially free of metal, while in other embodiments, the aromatic organic compound is completely free of metal.

  The softening / acceleration agent can also include a Group VIA component. Elemental sulfur and polymeric sulfur are commercially available from, for example, Elastochem, Chardon, Ohio. Examples of sulfur catalyst compounds include PB (RM-S) -80 elemental sulfur and PB (CRST) -65 polymer sulfur, each of which is available from Elastochem. An example of a tellurium catalyst under the trade name “TELLOY” and an example of a selenium catalyst under the trade name “VANDEX” are each commercially available from RT Vanderbilt.

  Other suitable softening and speeding agents include, but are not limited to, hydroquinone, benzoquinone, quinhydrone, catechol, and resorcinol.

The hydroquinone compound is selected from compounds represented by the following chemical formula and hydrates thereof.

Here, each of R ₁ , R ₂ , R ₃ and R ₄ is hydrogen; halogen; alkyl; carboxyl; its metal salt and its ester; acetate and its ester; formyl; acyl; acetyl group; Sulfonyl halide; sulfino; alkyl sulfinyl; carbamoyl; alkyl halide; cyano; alkoxy; hydroxy and metal salts thereof; amino; nitro; aryl; aryloxy; arylalkyl;

  Examples of other suitable hydroquinone compounds include, but are not limited to, hydroquinone; tetrachlorohydroquinone; 2-chlorohydroquinone; 2-bromohydroquinone; 2,5-dichlorohydroquinone; 2,5-dibromohydroquinone; tetrabromohydroquinone; 2-methylhydroquinone; 2-t-butylhydroquinone; 2,5-di-t-amylhydroquinone; and 2- (2-chlorophenyl) hydroquinone hydrate.

More suitable hydroquinone compounds include compounds represented by the following chemical formula and hydrates thereof.

Where R ₁ , R ₂ , R ₃ and R ₄ are each a carboxyl metal salt; acetate and its ester; hydroxy; hydroxy metal salt; amino; nitro; aryl; aryloxy; arylalkyl; nitroso; Or vinyl.

Suitable benzoquinone compounds include compounds represented by the following chemical formula and hydrates thereof.

Here, each of R ₁ , R ₂ , R ₃ and R ₄ is hydrogen; halogen; alkyl; carboxyl; its metal salt and its ester; acetate and its ester; formyl; acyl; acetyl group; Sulfonyl halide; sulfino; alkyl sulfinyl; carbamoyl; alkyl halide; cyano; alkoxy; hydroxy and metal salts thereof; amino; nitro; aryl; aryloxy; arylalkyl;

Other suitable benzoquinone compounds include one or more compounds represented by the following chemical formula and hydrates thereof.

Where R ₁ , R ₂ , R ₃ and R ₄ are each a carboxyl metal salt; acetate and its ester; hydroxy; hydroxy metal salt; amino; nitro; aryl; aryloxy; arylalkyl; nitroso; Or vinyl.

Suitable quinhydrones include one or more compounds represented by the following chemical formula and hydrates thereof.

Where R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each hydrogen; halogen; alkyl; carboxyl; carboxyl metal salt and ester; acetate and ester Acyl; acetyl; carbonyl halide; sulfo and esters thereof; sulfonyl halide; sulfino; alkylsulfinyl; carbamoyl; alkyl halide; cyano; alkoxy; hydroxy and its metal salts; Arylalkyl; nitroso; acetamide; or vinyl.

Other suitable quinhydrones are those having the above formula. Provided that R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each a carboxyl metal salt; acetate and its ester; hydroxy; hydroxy metal salt; amino; nitro; Aryl; aryloxy; arylalkyl; nitroso; acetamide; or vinyl.

Suitable catechols include one or more compounds represented by the following chemical formula and hydrates thereof.

Here, each of R ₁ , R ₂ , R ₃ and R ₄ is hydrogen; halogen; alkyl; carboxyl; its metal salt and its ester; acetate and its ester; formyl; acyl; acetyl group; Sulfonyl halide; sulfino; alkyl sulfinyl; carbamoyl; alkyl halide; cyano; alkoxy; hydroxy and metal salts thereof; amino; nitro; aryl; aryloxy; arylalkyl;

Suitable resorcinols include one or more compounds represented by the following chemical formula and hydrates thereof.

Here, each of R ₁ , R ₂ , R ₃ and R ₄ is hydrogen; halogen; alkyl; carboxyl; its metal salt and its ester; acetate and its ester; formyl; acyl; acetyl group; Sulfonyl halide; sulfino; alkyl sulfinyl; carbamoyl; alkyl halide; cyano; alkoxy; hydroxy and metal salts thereof; amino; nitro; aryl; aryloxy; arylalkyl;

  Fillers may also be added to the core thermosetting composition to adjust the density of the composition upward or downward. Fillers are typically tungsten, zinc oxide, barium sulfate, silica, calcium carbonate, zinc carbonate, metals, metal oxides and salts, liglind (recycled core material, typically about 30 mesh particles ), A high Mooney viscosity rubber liglind, a trans-riglind core material (a recycled core material containing a high trans-isomer of polybutadiene), and the like. When there is trans-ligrind, the amount of trans-isomer is preferably between about 10% and about 60%. In a preferred example of the present invention, the core comprises polybutadiene having a cis-isomer content of greater than about 95% and a trans-liglind material (already sulfided) as a filler. A trans-liglind core material of any particle size is sufficient, but is preferably less than about 125 μm.

  Fillers added to one or many parts of a golf ball typically include processing aids or compounds that affect rheological and mixing properties, density adjusting fillers, tear strength or reinforcing fillers, and the like. Fillers are generally inorganic and suitable fillers include a number of metals or metal oxides such as zinc oxide and tin oxide, as well as barium sulfate, zinc sulfate, calcium carbonate, barium carbonate, clay, tungsten, tungsten carbide, silica. Including arrays, and mixtures thereof. Fillers can also include various foaming or blowing agents, which can be easily selected by those skilled in the art. Fillers may include polymers, ceramics, and metals, and the glass microspheres may be solid or hollow and may or may not be filled. Fillers are also typically added to one or more parts of the golf ball to adjust its density and meet uniform golf ball standards. Fillers can also be used to adjust the mass of the at least one additional layer for the center or special ball, for example, a ball with a low mass is preferred for a player with a low swing speed.

  Such as tungsten, zinc oxide, barium sulfate, silica, calcium carbonate, zinc carbonate, metals, metal oxides and salts, liglind (recycled core material, typically ground to about 30 mesh particles) The material is also a suitable filler.

  Polybutadiene and / or any other base rubber or elastomer system is also foamed or filled with hollow microspheres or expandable microspheres that expand at set temperatures during the curing process to any low specific gravity level. It's okay. Other ingredients, such as sulfur promoters, specifically tetramethylthiuram, di, tri, or tetrasulfide, and / or metal-containing organic sulfur promoters may be used in accordance with the present invention. Suitable metal-containing organic sulfur promoters include, but are not limited to, cadmium, copper, lead, and ruthenium analogs of diethyldithiocarbamate, diamyldithiocarbamate, and dimethyldithiocarbamate or mixtures thereof. Other ingredients such as processing aids, specifically fatty acids and / or metal salts thereof, processing oils, dyes and pigments, and other additives well known to those skilled in the art A sufficient amount may be used to achieve

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A number of cores were produced based on the formulation and cure cycle described in Table 2 below, and their core hardness values are reported in Table 3 below.

(*) VANOX MBPC: R. T.A. 2,2′-methylene-bis- (4-methyl-6-tert-butylphenol) available from Vanderbilt
(**) TRIGONOX 265-50B: 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane and di (2-t 50% active on non-active carrier available from Akzo Nobel -Butylperoxyisopropyl) benzene mixture (***) Perkadox BC-FF: Dicumyl peroxide available from Akzo Nobel (99% -100% active)
(+) SR-526: ZDA available from Sartomer

  The surface hardness of the core is taken from the average of a number of measurements taken from the opposing hemisphere of the core, and care is taken not to make measurements on core separation lines or surface defects, such as holes or protrusions. The hardness is measured according to ASTM D-2240 “Durometer rubber and plastic dent hardness”. Since the core is a curved surface, it must be handled so that the core can be centered directly under the durometer indenter before the surface hardness can be read. One calibrated digital durometer capable of reading up to 0.1 units was used for all hardness measurements and was set to take a hardness reading 1 second after the maximum reading was obtained. The digital durometer must be mounted on the base of the auto stand with its legs parallel so that the weight and attack speed on the durometer conforms to ASTM D-2240.

  To prepare for the hardness gradient measurement of the core, the core is gently pushed into a hemispherical holder whose inner diameter is slightly smaller than the core diameter, and the core is held stationary in the hemispherical part of the holder, while at the same time the geometric center plane of the core To be exposed. The core is fixed in the holder by friction to prevent movement during the cutting and polishing steps. However, friction should not be excessive and the natural shape of the core should not be deformed. The core is fixed so that the separation line of the core is approximately parallel to the top of the holder. Before fixing the core, the core diameter is measured at 90 ° to this configuration. Also, the distance from the bottom of the holder to the top of the core is measured to obtain a reference point for future calibration. Roughly cut using a band saw or other suitable cutting tool, just above the exposed geometric center of the core, keeping the core from moving within the holder during this step. The remaining part of the core still held in the holder is secured to the base plate of the surface polisher. The exposed “rough” core surface is polished to a smooth, flat surface to reveal the core's geometric center, which can be verified by measuring the height from the bottom of the holder to the exposed surface of the core . This ensures that exactly half of the original height of the core has been removed within the range of + -0.004 inches.

  Hold the core in the holder, find the center of the core with a centering ruler, mark it carefully, and measure the hardness with this center mark. Hardness measurements at an arbitrary distance from the center of the core are made by drawing a line extending radially outward from the center and measuring and marking the distance from the center, typically in 2 mm increments. Even if all hardness measurements are performed on a plane that passes through the geometric center, the core is still in the holder so that its configuration is not disturbed and the measurement plane is always parallel to the bottom of the holder . The hardness difference from any predetermined point on the core is calculated by subtracting the appropriate reference point from the average surface hardness, e.g. for a single solid core, the hardness at the center of the core, and the core surface softer than the center is negative The hardness gradient is as follows.

  Referring to Tables 1 and 2, in Example 1, the surface is 10 shore C smaller than the center hardness and 12 shore C smaller than the highest hardness point in the core. In Example 3, the surface is 5 Shore C less than the center hardness and 8 Shore C less than the point of greatest hardness in the core. In Example 2, the center and surface hardness values are equal and the softest point in the core is 10 Shore C smaller than the surface.

  In the example of the invention presented in Table 1, the curing temperature varies from 305 ° F. (152 ° C.) to 320 ° F. (160 ° C.), and the curing time varies from 11 to 16 minutes. The core compositions of Examples 1 and 2 are vaginal and only the cure cycle is changed. In Example 3, the amount of antioxidant is the same as in Examples 1 and 2, but the other ingredients and the cure cycle are changed. Furthermore, the ratio of antioxidant to initiator changes from 0.50 to 0.57 in Examples 1, 2 and 3.

  The ratio of antioxidant to initiator is one factor that controls the surface hardness of the core. From the data shown in Table 2, it can be seen that the hardness gradient depends on, but is not limited to, the amount of antioxidant and peroxide, their ratio, and the cure cycle. Note that the more antioxidants, the more peroxide initiators are required to achieve the desired compression.

  The core of Comparative Example 1 is shown in Table 2 and was cured using a normal core cycle with a cure temperature of 350 ° F. (177 ° C.) and a cure time of 11 minutes. The core of this invention was manufactured using a cure cycle of 305 ° F. (152 ° C.), 14 minutes, 315 ° F. (157 ° C.), 11 minutes. The hardness gradient of these cores is measured and the following observations can be made. For the core of the comparative example, as expected, a normal gradient from a hard surface to a soft center can be clearly found. The gradients of the cores of the present invention take substantially the same shape as each other.

  In a preferred embodiment of the invention, the hardness of the core at the surface is at most about the same as or less than the hardness of the core at the center. Furthermore, the central hardness of the core may not be the hardest point in the core, but in all cases it is preferred that it be at least as hard as the surface. Furthermore, there is no need for the surface to have the least hardness anywhere in the core. In some embodiments, the smallest hardness value is within 6 mm outward of the core surface. However, as long as the surface hardness is still equal to or smaller than the center hardness, the smallest hardness value in the core may be at the surface or any point from the surface except the center. It should be noted that in the present invention, the preparation is the same throughout the core or core layer, and no surface treatment is applied to obtain a desirable surface hardness.

Although the golf balls of the present invention may be made from a variety of different conventional cover materials (both intermediate and outer cover layers), preferred cover materials include, but are not limited to:
(1) Polyurethanes, such as those prepared from polyols or polyamines and diisocyanates or polyisocyanates and / or prepolymers thereof, as well as in US Pat. Nos. 5,33,4673 and 6,506,851 What is disclosed.
(2) Polyureas such as those disclosed in US Pat. Nos. 5,484,870 and 6,835,794.
(3) A polyurethane-urea hybrid, blend or copolymer comprising urethane or urea segments.
Suitable polyurethane compositions include the reaction product of at least one polyisocyanate and at least one curing agent. The curing agent may include, for example, one or more polyamines, one or more polyols, or combinations thereof. The polyisocyanate may be combined with one or more polyols to form a prepolymer. This is combined with at least one curing agent as described above. Thus, the polyols described herein are suitable as one or both elements of the polyurethane material. That is, it is suitable for use as a part of the prepolymer and the curing agent. Suitable polyurethanes are described in US Patent Application Publication No. 2005/0176526, the contents of which are hereby incorporated by reference.

Any polyisocyanate available to those skilled in the art is suitable for use in accordance with the present invention. Examples of polyisocyanates include, but are not limited to: 4,4′-diphenylmethane diisocyanate (“MDI”); polymer MDI; carbodiimide-modified liquid MDI; 4,4′-dicyclohexylmethane diisocyanate (“H ₁₂ MDI”) P-phenylene diisocyanate (“PPDI”); m-phenylene diisocyanate (“MPDI”); toluene diisocyanate (“TDI”); 3,3′-dimethyl-4,4′-biphenylene diisocyanate (“TODI”); Isophorone diisocyanate ("IPDI"); hexamethylene diisocyanate ("HDI"); naphthalene diisocyanate ("NDI"); xylene diisocyanate ("XDI"); p-tetramethylxylene diisocyanate ("p-TM") DI "); m-tetramethylxylene diisocyanate (" m-TMXDI "); ethylene diisocyanate; propylene-1,2-diisocyanate; tetramethylene-1,4-diisocyanate; cyclohexyl diisocyanate; 1,6-hexamethylene-diisocyanate ( "HDI");dodecane-1,12-diisocyanate;cyclobutane-1,3-diisocyanate;cyclohexane-1,3-diisocyanate;cyclohexane-1,4-diisocyanate; 1-isocyanate-3,3,5-trimethyl-5 -Isocyanate methylcyclohexane; methylcyclohexylene diisocyanate; triisocyanate of HDI; triisocyanate of 2,4,4-trimethyl-1,6-hexane diisocyanate ("T DI "); tetracene diisocyanate; naphthalene diisocyanate; anthracene diisocyanate; and mixtures thereof; uretdione of hexamethylene diisocyanate; the isocyanurate of toluene diisocyanate. Polyisocyanates are known to those skilled in the art as having one or more isocyanate groups such as diisocyanates, triisocyanates and tetraisocyanates. Preferably, the polyisocyanate comprises MDI, PPDI, TDI, or mixtures thereof, more preferably the polyisocyanate comprises MDI. As used herein, the term “MDI” refers to 4,4′-diphenylmethane diisocyanate, polymeric MDI, carbodiimide modified liquid MDI, and mixtures thereof, and further the diisocyanate used is “low free monomer”. It should be understood by those skilled in the art that the amount of “free” monomer is a low isocyanate group, typically that the amount of free monomer group is less than about 0.1%. is there. Examples of “low free monomer” diisocyanates include, but are not limited to, low free monomer MDI, low free monomer TDI, and low free monomer PPDI.

  The at least one polyisocyanate should have less than about 14% unreacted NCO groups. Preferably, the at least one polyisocyanate has no more than about 8.0% NCO, more preferably no more than about 7.8%, and most preferably no more than about 7.5% NCO, conventionally about An NCO level of 7.2 or 7.0 or 6.5% NCO is used.

  Any polyol available to one skilled in the art is suitable for use in accordance with the present invention. Examples of polyols include, but are not limited to, polyether polyols, hydroxy-terminated polybutadienes (including partially / fully hydrogenated derivatives), polyester polyols, polycaprolactone polyols, and polycarbonate polyols. In a preferred embodiment, the polyol comprises a polyether polyol. Examples are, but not limited to, polytetramethylene ether glycol (“PTMEG”), polyethylene propylene glycol, polyoxypropylene glycol, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds and substituted or unsubstituted aromatic and cyclic groups. Preferably, the polyol of this invention comprises PTMEG.

  In another embodiment, the polyurethane material of this invention includes a polyester polyol. Suitable polyester polyols include, but are not limited to, polyethylene adipate glycol; polybutylene adipate glycol; polyethylene propylene adipate glycol; o-phthalate-1,6-hexanediol; poly (hexamethylene adipate) glycol; and mixtures thereof It is. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups.

  In another embodiment, the polyurethane material of this invention includes a polycaprolactone polyol. Suitable polycaprolactone polyols include, but are not limited to, 1,6-hexanediol-initiated polycaprolactone, diethylene glycol initiated polycaprolactone, trimethylolpropane initiated polycaprolactone, neopentyl glycol initiated polycaprolactone, 1,4-butanediol initiated Polycaprolactone, PTMEG-initiated polycaprolactone, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated, or substituted or unsubstituted aromatic and cyclic groups.

  In yet another embodiment, the polyurethane material of this invention includes a polycarbonate polyol. Suitable polycarbonates include, but are not limited to, polyphthalate carbonate and poly (hexamethylene carbonate) glycol. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. In one example, the molecular weight of the polyol is from about 200 to about 4000.

  Polyamine curing agents are also suitable for use in the polyurethane compositions of this invention and have been found to improve the cut resistance, shear resistance, and impact resistance of product balls. Preferred polyamine curing agents include, but are not limited to, 3,5-dimethylthio-2,4-toluenediamine and its isomer; 3,5-diethyltoluene-2,4-diamine and its isomer, such as 3,5-diethyl Toluene-2,6-diamine; 4,4′-bis- (sec-butylamino) -diphenylmethane; 1,4-bis- (sec-butylamino) -benzene, 4,4′-methylene-bis- (2 -Chloroaniline); 4,4'-methylene-bis- (3-chloro-2,6-diethylaniline) ("MCDEA"); polytetramethylene oxide-di-p-aminobenzoate; N, N'-dialkyl Diaminodiphenylmethane; p, p'-methylenedianiline ("MDA"); m-phenylenediamine ("MPDA"); -Methylene-bis- (2-chloroaniline) ("MOCA"); 4,4'-methylene-bis- (2,6-diethylaniline) ("MDEA"); 4,4'-methylene-bis- ( 2,3-dichloroaniline) (“MDCA”); 4,4′-diamino-3,3′-diethyl-5,5′-dimethyldiphenylmethane; 2,2′-3,3′-tetrachlorodiaminodiphenylmethane; Trimethylene glycol di-p-aminobenzoate; and mixtures thereof. Preferably, the curing agent of the present invention is 3,5-dimethylthio-2,4-toluenediamine and its isomers, such as Ethacure® available from Albemarle Corporation of Baton Rouge, LA. 300. Suitable polyamine curing agents include both primary and secondary amines, and preferably have a molecular weight in the range of about 64 to about 2000.

  At least one diol, triol, tetraol, or hydroxy-terminated curing agent can be added to the polyurethane composition described above. Suitable diol, triol, and tetraol groups include: ethylene glycol; diethylene glycol; polyethylene glycol; propylene glycol; polypropylene glycol; low molecular weight polytetramethylene ether glycol; 1,3-bis- [2- (2-hydroxyethoxy) ethoxy] benzene; 1,3-bis- {2- [2- (2-hydroxyethoxy) ethoxy] ethoxy} benzene; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol; resorcinol-di- (β-hydroxyethyl) ether; hydroquinone-di- (β-hydroxyethyl) ether; and mixtures thereof. Preferred hydroxy-terminated curing agents are 1,3-bis (2-hydroxyethoxy) benzene; 1,3-bis- [2- (2-hydroxyethoxy) ethoxy] benzene; 1,3-bis- {2- [2 -(2-hydroxyethoxy) ethoxy] ethoxy} benzene; 1,4-butanediol, and mixtures thereof. Preferably, the molecular weight of the hydroxy-terminated curing agent ranges from about 48 to about 2000. Here, the molecular weight is the absolute weight average Bunshiro, as understood by those skilled in the art.

  Both the hydroxy terminus and the amine curing agent can contain one or more saturated, unsaturated, aromatic, and cyclic groups. In addition, the hydroxy terminus and the amine curing agent can include one or more halogen groups. Polyurethane compositions can be made by blends or mixtures of curing agents. However, if desired, the polyurethane composition can be made with a single curing agent.

  In a preferred embodiment of the present invention, the saturated polyurethane used to form the cover layer, particularly the outer cover layer, can be selected from both castable thermoset and thermoplastic polyurethane.

  In this example, the saturated polyurethane of this invention is substantially free of aromatic groups or moieties. Saturated polyurethanes suitable for use in the present invention are reaction products of at least one polyurethane prepolymer and at least one saturated curing agent. The polyurethane prepolymer is a reaction product of at least one polyol and at least one saturated diisocyanate. As is well known in the art, a catalyst may be employed to promote the reaction of the curing agent and the isocyanate and polyol.

  Saturated diisocyanates that can be used include, but are not limited to, ethylene diisocyanate; propylene-1,2-diisocyanate; tetramethylene-1,4-diisocyanate; 1,6-hexamethylene diisocyanate ("HDI"); 2,4,4-trimethylhexamethylene diisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1 , 4-diisocyanate; 1-isocyanate-3,3,5-trimethyl-5-isocyanate methylcyclohexane; isophorone diisocyanate; methylcyclohexylene dii Cyanate; HDI triisocyanate, including triisocyanate 2,2,4-trimethyl-1,6-hexane diisocyanate. The most preferred saturated diisocyanates are 4,4'-dicyclohexylmethane diisocyanate and isophorone diisocyanate.

  Saturated polyols suitable for use in the present invention include, but are not limited to, polyether polyols such as polytetramethylene ether glycol and poly (oxypropylene) glycol. Suitable saturated polyester polyols are polyethylene adipate glycol, polyethylene propylene adipate glycol, polybutylene adipate glycol, polycarbonate polyol and ethylene oxide capped polyoxypropylene diol. Saturated polycaprolactone polyols useful in this invention include diethylene glycol initiated polycaprolactone, 1,4-butanediol initiated polycaprolactone, 1,6-hexanediol initiated polycaprolactone; trimethylolpropane initiated polycaprolactone, neopentyl glycol initiated polycaprolactone, And polytetremethyl ether glycol initiated polycaprolactone. The most preferred saturated polyols are PTMEG and PTMEG initiated polycaprolactone.

  Suitable saturated hardeners are 1,4-butanediol, ethylene glycol, diethylene glycol, polytetramethylene ether glycol, propylene glycol; trimethanol propane; tetra- (2-hydroxypropyl) -ethylenediamine; isomers of cyclohexyldimethylol isomers. And mixtures, isomers and mixtures of isomers of cyclohexanebis (methylamine); triisopropanolamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 4,4'-dicyclohexylmethanediamine, 2,2,4-trimethyl- 1,6-hexanediamine; 2,4,4-trimethyl-1,6-hexanediamine; diethylene glycol di- (aminopropyl) ether 4,4′-bis- (sec-butylamino) -dicyclohexylmethane; 1,2-bis- (sec-butylamino) cyclohexane; 1,4-bis- (sec-butylamino) cyclohexane; isophoronediamine, hexamethylene Diamine, propylenediamine, 1-methyl-2,4-cyclohexyldiamine, 1-methyl-2,6-cyclohexyldiamine, 1,3-diaminopropane, dimethylaminopropylamine, diethylaminopropylamine, imido-bis-propylamine, Isomers and mixtures of diaminocyclohexane isomers, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, and diisopropanolamine. The most preferred saturated curing agents are 1,4-butanediol, 1,4-cyclohexyldimethylol and 4,4'-bis- (sec-butylamino) -dicyclohexylmethane.

  Alternatively, other suitable polymers include partially or fully neutralized ionomers, metallocenes, or other single site catalyst polymers, polyesters, polyamides, non-ionomer thermoplastic elastomers, copolyether-esters, Copolyether-amides, polycarbonates, polybutadienes, polyisoprenes, polystyrene block copolymers (eg, styrene-butadiene-styrene), styrene-ethylene-propylene-styrene, styrene-ethylene-butylene-styrene, and the like, and blends thereof. Thermosetting polyurethane or polyurea is suitable as the outer cover layer of the golf ball of the present invention.

  Further, the polyurethane may be replaced with a polyurea material or blended. Polyureas are clearly different from polyurethane compositions, but provide the desired aerodynamic and aesthetic properties when used in golf ball components. The polyurea-based composition is preferably saturated in nature.

  Without being bound by any particular theory, by replacing the long chain polyol segment in the polyurethane prepolymer with a long chain polyetherdiamine oligomer soft segment to form a polyurea prepolymer, shear, cut and It is currently believed that the impact resilience is improved and the adhesion to other components is improved. Accordingly, the polyurea composition of the present invention comprises a reaction product of an isocyanate and a polyamine prepolymer crosslinked with a curing agent. For example, the polyurea-based composition of the present invention may be prepared from at least one isocyanate, at least one polyetheramine, and at least one diol curing agent or at least one diamine curing agent.

  All polyamines available to those skilled in the art are suitable for use in the polyurea prepolymer. Polyether amines are particularly suitable in the prepolymer. As used herein, the term “polyetheramine” means at least a polyoxyalkyleneamine comprising a primary amino group bonded to the end of the polyether backbone. However, the choice of diamines and polyetheramines is limited to those that allow the formation of polyurea prepolymers due to the rapid reaction of isocyanate and amine and the insolubility of many urea products. In one example, the polyether backbone is based on tetramethylene, propylene, ethylene, trimethylolpropane, glycerin, and mixtures thereof.

  Suitable polyether amines include, but are not limited to, polytetramethylene ether diamine, polyoxypropylene diamine, poly (ethylene oxide terminated oxypropylene) ether diamine, triethylene glycol diamine, propylene oxide based triamine, trimethylol propane Based triamines, glycerin based triamines, and mixtures thereof. In one example, the polyetheramine used to make the prepolymer is JEFFAMINE ™ D2000 (Huntsman, Austin, Texas).

  The molecular weight of the polyetheramine used in the polyurea prepolymer is in the range of about 100 to about 5000. In one example, the molecular weight of the polyetheramine is about 230 or greater. In other examples, the molecular weight of the polyetheramine is about 4000 or less. In yet another embodiment, the molecular weight of the polyetheramine is about 600 or greater. In yet another embodiment, the molecular weight of the polyetheramine is about 3000 or less. In yet another embodiment, the molecular weight of the polyetheramine is about 1000 to about 3000, more preferably about 1500 to about 2500. Since low molecular weight polyether ethers tend to form solid polyureas, large molecular weight oligomers such as JEFFAMINE D2000 are preferred.

  As mentioned briefly above, many amines are unsuitable for reaction with isocyanates due to the rapid reaction of amines with isocyanates. In particular, short-chain amines react quickly. However, in one example, a sterically hindered second diamine may be suitable for use in a prepolymer. Without being bound by any particular theory, amines with a high degree of steric hindrance, such as amines with a tertiary butyl group attached to the nitrogen atom, are more kinetic than amines with no or less hindrance. Is thought to be slow. For example, 4,4'-bis- (sec-butylamino) -dicyclohexylmethane (CLEARLINK ™ 1000) may be suitable for producing a polyurea prepolymer in combination with an isocyanate.

  Any isocyanate available to those skilled in the art is suitable for use in the polyurea prepolymer. The isocyanates used in the present invention are aliphatic, cycloaliphatic, araliphatic, aromatic, any of these derivatives, and combinations of these compounds having two or more isocyanate (NCO) groups per molecule. Including. Isocyanates can be organic polyisocyanate-terminated prepolymers, lower free isocyanates, and mixtures thereof. The reactive component comprising an isocyanate can include any isocyanate functional monomer, dimer, trimer, or multimeric adducts, prepolymers, pseudoprepolymers, or mixtures thereof. Isocyanate functional compounds can include monoisocyanates or polyisocyanates containing two or more isocyanate functional groups.

  Suitable isocyanate-containing components include diisocyanates having the following general formula: O═C═N—R—N═C═O, wherein R is preferably cyclic, aromatic containing from about 1 to about 20 carbon atoms. Or a straight or branched hydrocarbon moiety. The diisocyanate may further comprise one or more cyclic groups or one or more phenyl groups. When a polycyclic group or aromatic group is present, linear and / or branched hydrocarbons containing from about 1 to about 10 carbon atoms can be present as a spacer between the cyclic group or aromatic group. . In some cases, the cyclic or aromatic group may be substituted in the 2-, 3-, and / or 4-position, or in the ortho-, meta- and / or para-position, respectively. The substituted group is, but not limited to, a halogen, a first, second, or third hydrocarbon group, or a mixture thereof.

  Examples of diisocyanates that can be used in this invention include, but are not limited to, substituted and isomeric mixtures including 2,2'-, 2,4'-, and 4,4'-diphenylmethane diisocyanate; 3'-dimethyl-4,4'-biphenylene diisocyanate; toluene diisocyanate; polymer MDI; carbodiimide-modified liquid 4,4'-diphenylmethane diisocyanate; para-phenylene diisocyanate; meta-phenylene diisocyanate; triphenylmethane-4,4'- And triphenylmethane-4,4 "-triisocyanate; naphthylene-1,5-diisocyanate; 2,4'-, 4,4'- and 2,2-biphenyl diisocyanate; polyphenylpolymethylene polyisocyanate; and MDI PMDI blend A mixture of PMDI and TDI; ethylene diisocyanate; propylene-1,2-diisocyanate; tetramethylene-1,2-diisocyanate; tetramethylene-1,3-diisocyanate; tetramethylene-1,4-diisocyanate; Octamethylene diisocyanate; octamethylene diisocyanate; decamethylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate; cyclobutane-1, 3-diisocyanate; cyclohexane-1,2-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate Methyl-cyclohexylene diisocyanate; 2,6-methylcyclohexane diisocyanate; 4,4'-dicyclohexyl diisocyanate; 2,4'-dicyclohexyl diisocyanate; 1,3,5-cyclohexane triisocyanate; Isocyanate methylcyclohexane isocyanate; 1-isocyanate-3,3,5-trimethyl-5-isocyanate methylcyclohexane; isocyanate ethylcyclohexane isocyanate; bis (isocyanatemethyl) -cyclohexane diisocyanate; 4,4′-bis (isocyanatemethyl) dicyclohexane 2,4'-bis (isocyanatomethyl) dicyclohexane; isophorone diisocyanate; HD Triisocyanate of I; Triisocyanate of 2,2,4-trimethyl-1,6-hexane diisocyanate; 4,4′-dicyclohexylmethane diisocyanate; 2,4-hexahydrotoluene diisocyanate; 2,6-hexahydrotoluene diisocyanate; 1,2-, 1,3- and 1,4-phenylene diisocyanates; aromatic aliphatic isocyanates such as 1,2-, 1,3- and 1,4-xylene diisocyanates; meta-tetramethylxylene diisocyanates; Para-tetramethylxylene diisocyanate; trimerized isocyanurate of any polyisocyanate, for example isocyanurate of toluene diisocyanate, trimer of diphenylmethane diisocyanate, tetramethylxylene diisocyanate Trimer, hexamethylene diisocyanate isocyanurate, and mixtures thereof; dimerized ureizions of any polyisocyanate, such as uretdione of toluene diisocyanate, uretdione of hexamethylene diisocyanate, and mixtures thereof; Modified polyisocyanates derived from polyisocyanates; and mixtures thereof.

  Examples of saturated diisocyanates that can be used in this invention include, but are not limited to, ethylene diisocyanate; propylene-1,2-diisocyanate; tetramethylene-diisocyanate; tetramethylene-1,4-diisocyanate; 1,6-hexa Octamethylene diisocyanate; decamethylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate; cyclobutane-1,3 -Diisocyanate; Cyclohexane-1,2-diisocyanate; Cyclohexane-1,3-diisocyanate; Cyclohexane-1,4-diisocyanate 2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane diisocyanate; 4,4'-dicyclohexyl diisocyanate; 2,4'-dicyclohexyl diisocyanate; 1,3,5-cyclohexane triisocyanate Isocyanate methylcyclohexane isocyanate; 1-isocyanate-3,3,5-trimethyl-5-isocyanate methylcyclohexane; isocyanate ethylcyclohexane isocyanate; bis (isocyanatemethyl) -cyclohexane diisocyanate; 4,4′-bis (isocyanatemethyl) dicyclohexane 2,4′-bis (isocyanatomethyl) dicyclohexane; isophorone diisocyanate; HD 2,4,4-trimethyl-1,6-hexane diisocyanate; 4,4'-dicyclohexylmethane diisocyanate; 2,4-hexahydrotoluene diisocyanate; 2,6-hexahydrotoluene diisocyanate; Including these mixtures. Aromatic aliphatic isocyanates can also be used to produce light stable materials. Examples of these isocyanates include: 1,2-, 1,3- and 1,4-xylene diisocyanates; meta-tetramethylxylene diisocyanate (m-TMXDI); para-tetramethylxylene diisocyanate (p-TMXDI) ); Trimerized isocyanurate of any polyisocyanate, for example, isocyanurate of toluene diisocyanate, trimer of diphenylmethane diisocyanate, trimer of tetramethylxylene diisocyanate, isocyanurate of hexamethylene diisocyanate, and mixtures thereof; A dimerized ureizion of any of the polyisocyanates, such as uretdione of toluene diisocyanate, uretdione of hexamethylene diisocyanate, and mixtures thereof; It is and mixtures thereof; where over preparative and polyisocyanates modified derived from a polyisocyanate. Furthermore, aromatic aliphatic isocyanates can be mixed with any of the saturated isocyanates listed above for the purposes of the present invention.

  By varying the number of unreacted NCO groups in the polyurea prepolymer of isocyanate and polyetheramine, factors such as the rate of reaction and the hardness of the resulting composition can be controlled. For example, the number of unreacted NCO groups in the polyurea prepolymer of isocyanate and polyetheramine can be less than about 14%. In one example, the polyurea prepolymer has from about 5% to about 11% unreacted NCO groups, more preferably from about 6% to about 9.5% unreacted NCO groups. In one example, the proportion of unreacted NCO groups is about 3% to about 9%. Alternatively, the proportion of unreacted NCO groups is about 7.5% or lower, more preferably about 7% or lower. In other examples, the proportion of unreacted NCO groups is from about 2.5% to about 7.5%, more preferably from about 4% to about 6.5%.

  As produced, the polyurea prepolymer may comprise from about 10% to about 20% by weight of the free isocyanate monomer of the prepolymer. As a result, in one embodiment, free isocyanate monomer may be removed from the polyurea prepolymer. For example, after removal, the prepolymer will contain 1% or less of free isocyanate monomer. In other examples, the prepolymer may comprise about 0.5% by weight or less than free isocyanate monomer.

  Polyetheramine can also be blended with additional polyol to form a copolymer that can be reacted with excess isocyanate to produce a polyurea prepolymer. In one embodiment, less than about 30% by weight of the copolymer is blended with a saturated polyetheramine. In other examples, less than about 20% by weight of the copolymer, preferably less than about 15% by weight of the copolymer is blended with a saturated polyetheramine. Any saturated polyol available to those skilled in the art, such as polyether polyols, polycaprolactone polyols, polyester polyols, polycarbonate polyols, hydrocarbon polyols, other polyols, and mixtures thereof are suitable for blending in accordance with the present invention. Yes. The molecular weight of these polymers can be from about 200 to about 4000, but can be from about 1000 to about 3000, more preferably from about 1500 to about 2500.

  Polyurea compositions can be made by cross-linking a polyurea prepolymer with a single curing agent or blend thereof. The curing agent used in this invention is preferably an amine-terminated curing agent, more preferably a second diamine curing agent, so that the composition contains only a single urea bond. In one embodiment, the molecular weight of the amine-terminated curing agent is about 64 or greater. In other examples, the molecular weight of the amine-terminated curing agent is about 2000 or less. As noted above, certain amine-terminal curing agents may be modified with a compatible amine-terminal freezing point depressant or mixture thereof.

  Suitable amine-terminated curing agents include, but are not limited to, ethylenediamine; hexamethylenediamine; 1-methyl-2,6-cyclohexyldiamine; tetrahydroxypropyleneethylenediamine; 2,2,4- and 2,4,4- Trimethyl-1,6-hexanediamine; 4,4′-bis- (sec-butylamino) -dicyclohexylmethane; 1,4-bis- (sec-butylamino) -cyclohexane; 1,2-bis- (sec- Butylamino) -cyclohexane; 4,4′-bis- (sec-butylamino) -dicyclohexylmethane derivative; 4,4′-dicyclohexylmethanediamine; 1,4-cyclohexane-bis- (methylamine); -Cyclohexane-bis- (methylamine); diethylene glycol di- (amino 2-propylpentamethylene-diamine; diaminocyclohexane; diethylenetriamine; triethylenetetramine; tetraethylenepentamine; propylenediamine; 1,3-diaminopropane; dimethylaminopropylamine; diethylaminopropylamine; imido-bis-propyl Amine; monoethanolamine, diethanolamine; triethanolamine; monoisopropanolamine, diisopropanolamine; isophoronediamine; 4,4′-methylenebis- (2-chloroaniline); 3,5-dimethylthio-2,4-toluenediamine; 3,5-dimethylthio-2,6-toluenediamine; 3,5-diethylthio-2,4-toluenediamine; 3,5-diethylthio-2,6-toluenediamine 4,4′-bis- (sec-butylamino) -diphenylmethane and its derivatives; 1,4-bis- (sec-butylamino) -benzene; 1,2-bis- (sec-butylamino) -benzene; N , N′-dialkylamino-diphenylmethane; trimethylene glycol-di-aminobenzoate; polytetramethylene oxide-di-p-aminobenzoate; 4,4′-methylenebis- (3-chloro-2,6-diethyleneaniline); 4,4'-methylenebis- (2,6-diethylaniline); meta-phenylenediamine; para-phenylenediamine; cyclohexyldimethol; and mixtures thereof. In one example, the amine-terminated curing agent is 4,4'-bis- (sec-butylamino) -dicyclohexylmethane.

  Suitable saturated amine-terminated curing agents include, but are not limited to, ethylenediamine; hexamethylenediamine; 1-methyl-2,6-cyclohexyldiamine; tetrahydroxypropyleneethylenediamine; 2,2,4- and 2,4,4. -Trimethyl-1,6-hexanediamine; 4,4'-bis- (sec-butylamino) -dicyclohexylmethane; 1,4-bis- (sec-butylamino) -cyclohexane; 1,2-bis- (sec -Butylamino) -cyclohexane; 4,4'-bis- (sec-butylamino) -dicyclohexylmethane derivative; 4,4'-dicyclohexylmethanediamine; 1,4-cyclohexane-bis- (methylamine); 3-cyclohexane-bis- (methylamine); diethylene glycol di- 2-aminopentamethylene-diamine; diaminocyclohexane; diethylenetriamine; triethylenetetramine; tetraethylenepentamine; propylenediamine; 1,3-diaminopropane; dimethylaminopropylamine; diethylaminopropylamine; -Propylamine; monoethanolamine, diethanolamine; triethanolamine; monoisopropanolamine, diisopropanolamine; isophoronediamine; triisopropanolamine; and mixtures thereof. In addition, any of the above polyether amines can be used as a curing agent to react with the polyurea prepolymer.

  The center and optional layer of a golf ball can be made from a highly neutralized polymer (“HNP”). The acid portion of HNP is typically an ethylene-based ionomer, preferably more than about 70%, more preferably more than about 90%, and most preferably at least about 100% neutralized. HNP can also be blended with the second polymer component, and if this component contains acid groups, it can be neutralized according to conventional methods, with organic fatty acids of the present invention, or both. . The second polymer component may be partially or fully neutralized, preferably ionomer copolymers and ionomer terpolymers, ionomer precursors, thermoplastics, polyamides, polycarbonates, polyesters, polyurethanes, polyureas, heat Includes plastic elastomers, polybutadiene rubber, balata, metallocene catalyzed polymers (grafted and ungrafted), single site polymers, highly crystalline acid polymers, cationic ionomers, and the like. The material hardness of the HNP polymer is typically between about 20 and about 80 Shore D, and the flexural modulus is between about 3,000 psi and about 200,000.

In one embodiment of the invention, the HNP is an ionomer and / or an acid precursor thereof, which is preferably fully or partially neutralized with an organic acid copolymer or salt thereof. The acid copolymer is preferably an α-olefin, such as ethylene, a C _3-8 α, β-ethylenically unsaturated carboxylic acid, such as an acrylic or methacrylic acid copolymer. These may optionally contain softening monomers such as alkyl acrylates and alkyl methacrylates. However, the acryl group comprises 1 to 8 carbon atoms.

The acid copolymer can be described as an E / X / Y copolymer, where E is ethylene, X is an α, β-ethylenically unsaturated carboxylic acid, and Y is a softening comonomer. In a preferred embodiment, X is acrylic acid or methacrylic acid and Y is a C _1-8 alkyl acrylate or methacrylate ester. X is preferably present in an amount of from about 1 to about 35% by weight of the polymer, more preferably from about 5 to about 30% by weight of the polymer, and most preferably from about 10 to about 20% by weight of the polymer. Y is preferably present in an amount of from about 0 to about 50% by weight of the polymer, more preferably from about 5 to about 25% by weight of the polymer, and most preferably from about 10 to about 20% by weight of the polymer.

  Specific acid-containing ethylene copolymers include, but are not limited to, ethylene / acrylic acid / n-butyl acrylate, ethylene / methacrylic acid / n-butyl acrylate, ethylene / methacrylic acid / iso-butyl acrylate, ethylene / acrylic acid / Iso-butyl acrylate, ethylene / methacrylic acid / methyl acrylate, ethylene / methacrylic acid / n-butyl methacrylate, ethylene / acrylic acid / methyl methacrylate, ethylene / acrylic acid / methyl acrylate, ethylene / methacrylic acid / methyl acrylate, ethylene / methacryl Acid / methyl methacrylate and ethylene / acrylic acid / n-butyl methacrylate. Preferred acid-containing ethylene copolymers are ethylene / methacrylic acid / n-butyl acrylate, ethylene / acrylic acid / n-butyl acrylate, ethylene / methacrylic acid / methyl acrylate, ethylene / acrylic acid / ethyl acrylate, ethylene / methacrylic acid / ethyl acrylate. And ethylene / acrylic acid / methyl acrylate copolymers. The most preferred acid-containing ethylene copolymers are ethylene / (meth) acrylic acid / n-butyl acrylate, ethylene / (meth) acrylic acid / ethyl acrylate, and ethylene / (meth) acrylic acid / methyl acrylate copolymers.

  The ionomer is typically neutralized by metal cations such as Li, Na, Mg, K, Ca, or Zn. By adding enough organic acid or salt of organic acid, along with an appropriate base, to the acid copolymer or ionomer, the ionomer is neutralized to a much higher level relative to the metal cation without sacrificing processability. The Preferably, the acid moiety is neutralized about 80% or more, preferably 90-100% neutralized, most preferably 100% neutralized. However, workability is not impaired. This involves melt blending an α, β-ethylenically unsaturated carboxylic acid copolymer with, for example, an organic acid or a salt of an organic acid, and then adding a sufficient amount of cation source to add all acid moieties (acid copolymer and organic acid). Of the acid moiety) is increased by more than 90% (preferably more than 100%).

  The organic acids of this invention are aliphatic, mono- or multi-functional (saturated, unsaturated, or polyunsaturated) organic acids. These organic acid salts can also be used. The organic acid salt of the present invention is composed of barium, lithium, sodium, zinc, bismuth, chromium, cobalt, copper, potassium, strontium, titanium, tungsten, magnesium, cesium, iron, nickel, silver, aluminum, tin, or calcium. Salts, salts of fatty acids, in particular salts of stearic acid, behenic acid, erucic acid, oleic acid, linoleic acid or dimerized derivatives thereof. The organic acids and salts of the present invention must be relatively non-migratory (do not cause blooming on the surface of the polymer under normal pressure) and be non-volatile (do not evaporate at the temperature required for melt blending). preferable.

  The ionomers of this invention may also be more conventional ionomers, i.e. partially neutralized with metal cations. The acid portion of the acid copolymer may be from about 1 to about 100%, preferably at least about 40, depending on the cation, such as lithium, sodium, potassium, magnesium, calcium, barium, lead, tin, zinc, aluminum, or mixtures thereof. About 100%, more preferably at least about 90 to about 100% neutralized to produce an ionomer.

  In a preferred embodiment, the single layer core of the present invention is surrounded by two cover layers, and the thickness of the inner cover layer is from about 0.01 inches to about 0.06 inches, more preferably from about 0.015 inches to about 0. 0.040 inches, most preferably from about 0.02 inches to about 0.035 inches, and the inner cover layer has a Shore D hardness of greater than about 55, more preferably greater than about 60, and most preferably greater than about 65. Manufactured from large, partially or fully neutralized ionomers. In this embodiment, the thickness of the outer cover layer is from about 0.015 inches to about 0.055 inches, more preferably from about 0.02 inches to about 0.04 inches, and most preferably from about 0.025 inches to about 0. 0.035 inch and its hardness should be about Shore D60 or less, more preferably about 55 or less, and most preferably about 52 or less. The inner cover layer needs to be harder than the outer cover layer. In this embodiment, the outer cover layer has a partially or fully neutralized ionomer, polyurethane, polyurea, or blend thereof. The most preferred outer cover layer is castable or reactive injection molded polyurethane, polyurea, or a hybrid thereof, with a Shore D hardness of about 40 to about 50. The most preferred inner cover layer material is a partially neutralized ionomer having an ionomer neutralized with zinc, sodium, or lithium, such as SURLYN ™ 8940, 8945, 9910, 7930, 7940 or blends thereof The Shore D hardness is about 63 to about 68.

  In other multilayer cover, single core embodiments, the outer cover and inner cover layers are the same material and thickness, but the hardness range is reversed. That is, the outer cover layer is harder than the inner cover layer.

  In an alternative preferred embodiment, the golf ball is a one-piece golf ball that has a dimple surface and whose surface hardness is less than or equal to the center hardness (ie, a negative hardness gradient). Preferably, the one-piece ball has a diameter of about 1.680 inches to about 1.690 inches, its weight is about 1.620 ounces, its Atti compression is about 40 to 120, and its COR is about 0.750 to about 0.825. It is.

  In a preferred two-piece ball embodiment, a single layer core with a negative hardness gradient is a single layer core with a Shore D hardness of about 20 to about 80, more preferably about 40 to about 75, and most preferably about 45 to about 70. Encapsulated in cover material, thermoplastic or thermoset polyurethane, polyurea, polyamide, polyester, polyester elastomer, polyether-amide or polyester-amide, partially or fully neutralized ionomer, polyolefin, eg polyethylene, polypropylene Polyethylene copolymers, such as ethylene-butyl acrylate or ethylene-methyl acrylate, poly (ethylene methacrylic acid) co- and terpolymers, metallocene-catalyzed polyolefins, polar group functional polyolefins, and their blends Having. A preferred cover material in the two-piece embodiment is an ionomer (ordinary or HNP) having a hardness of about 50 to about 70 Shore D. In the two-piece embodiment, another preferred cover material is a thermoplastic or thermoset polyurethane or polyurea. Preferred ionomers are high acid ionomers having a copolymer of ethylene and methacrylic acid or acrylic acid and having an acid content of at least 16 to about 25 weight percent. In this case, the spin reduction caused by the relatively strong, high acid ionomer is offset to some extent by the negative gradient core that increases spin. The core diameter may be from about 1.0 inch to about 1.64 inch, preferably from about 1.30 inch to about 1.620 inch, and most preferably from about 1.40 inch to about 1.60 inch.

  Other preferred cover materials have a castable or reactive injection moldable polyurethane, polyurea, or polyurethane / polyurea copolymer or hybrid. Preferably, the cover is thermoset but may be thermoplastic and has a Shore D hardness of about 20 to about 70, more preferably about 30 to about 65, and most preferably about 35 to about 60. is there. Covers water vapor barrier layers such as those disclosed in US Pat. Nos. 6,632,147, 6,932,720, 7,004,854, and 7,182,702 Adopt as an option between layer and core. These patent documents are incorporated herein by reference.

  Although any of the embodiments shown here may involve any known number of dimples and patterns, the preferred number of dimples is from 252 to 456, more preferably from 330 to 392. The dimples may have any width, depth, and edge angle disclosed in the prior art, and the pattern may have a plurality of dimples with different widths, depths, and edge angles. The separation line structure of such a pattern may be a straight line or an alternating wavy separation line (SWPL: Staggered Wave Parting Line). Most preferably, the number of dimples is 330, 332, or 392, with dimple dimensions of 5 to 7. The separation line is SWPL.

  In any of these embodiments, the single layer core may be replaced with a core consisting of two or more layers. However. At least one core layer has a negative hardness gradient.

  Other things in the working examples, or all numerical ranges, quantities, values, percentages, such as those for the quantity of material, and others in the specification, even if not explicitly stated, even if the value, quantity or Even if the term “about” is not displayed in relation to a range, it can be read as if “about” is placed in front of it. Accordingly, unless indicated otherwise, the numerical parameters set forth in the specification and claims are approximate, depending on the desired characteristics that are contemplated by the present invention. Change. At a minimum, of course, it does not limit the application of the doctrine of equivalents, but each number of parameters should be interpreted in the light of the number of significant digits recorded and the normal rounding process.

  Although the numerical ranges and parameters representing the broad scope of the invention are approximate, the numerical values shown in the examples were recorded as accurately as possible. Any numerical value still contains errors necessarily resulting from the standard deviation found in each test measurement. Further, it should be understood that any combination of values, including the exemplified values, can be used where numerical ranges of various scopes are indicated.

  While it will be appreciated that the exemplary embodiments of the invention described herein will satisfy preferred embodiments of the invention, it should be understood that various modifications and other embodiments can occur to those skilled in the art. Examples of such changes include slight changes in the numerical values described above. Accordingly, the numerical values recited above and in the claims include such numerical values and include values that are close to or very close to the values described above and recited in the claims. Accordingly, the claims are intended to cover all such modifications and other embodiments, and are to be understood as falling within the spirit and scope of this invention.

Claims (11)

A single core comprising a mass, an outer surface, a geometric center, and an outermost transition adjacent to the outer surface, made from a substantially uniform composition;
A cover layer,
The outermost transition is disposed between the outer surface of the core and the geometric center, the transition includes an outer portion that coincides with the outer surface of the core, the outermost 5 of the core volume; % To 40%,
And both the hardness of the outer surface of the core and the hardness in the outermost transition part are smaller than the hardness of the geometric center, forming a negative hardness gradient,
Furthermore, between the single core and the cover layer has an outer core layer with a hardness of the outer surface larger than that of the inner surface and a positive hardness gradient,
Further, the cover layer includes an inner cover layer and an outer cover layer, and the outer cover layer includes polyurethane, polyurea, or a hybrid thereof. The golf ball according to claim 1, wherein the transition portion has an outermost 10% to 30% of the volume of the core. The golf ball according to claim 2, wherein the transition portion has an outermost 10% to 20% of the volume of the core. The golf ball according to claim 1, wherein the transition portion has a thickness of 0.65 mm to 2.5 mm. The golf ball according to claim 4, wherein the transition portion has a thickness of 0.75 mm to 1.9 mm. The golf ball according to claim 5, wherein the transition portion has a thickness of 1 mm to 1.5 mm. The golf ball of claim 1, wherein the hardness of the outer surface of the core is 1 Shore C to 10 Shore C less than the hardness of the geometric center. The golf ball of claim 7, wherein the hardness of the outer surface of the core is 1 Shore C to 5 Shore C less than the hardness of the geometric center. The golf ball of claim 1, wherein the transition portion has an inner portion, and the hardness in the transition portion decreases at least 2 Shore C / mm in a direction away from the inner portion to the outer portion. The golf ball according to claim 9, wherein the transition portion has an inner portion, and the hardness in the transition portion decreases by at least 3 Shore C / mm in a direction away from the inner portion to the outer portion. The golf ball of claim 10, wherein the transition portion has an inner portion, and the hardness in the transition portion decreases at least 4 shore C / mm in a direction away from the inner portion to the outer portion.