JP2007138375A - Ultrafine staple fiber nonwoven fabric and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrafine staple fiber nonwoven fabric suitable for the manufacture of a leather-like sheet and provide a leather-like sheet material having excellent feeling of fullness. <P>SOLUTION: The ultrafine staple fiber nonwoven fabric contains ultrafine fibers having a single fiber fineness of 0.0001-0.5 dtex and has a fabric weight of 100-550 g/m<SP>2</SP>, a tensile strength of ≥70 N/cm, a tear strength of 3-50 N and an abrasion resistance of Class 3 to 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrafine short fiber nonwoven fabric particularly suitable for a leather-like sheet and a method for producing the same. More specifically, the present invention relates to an ultrafine short fiber nonwoven fabric excellent in wear properties that is mainly made of a fiber material and can be used for a texture, shoes, furniture, clothing, etc. sufficient as a leather-like sheet, and a method for producing the same.

A leather-like sheet made of ultrafine fibers and a polymer elastic body has a touch similar to that of natural leather, and has excellent features not found in natural leather such as easy-care. Widely used.
In producing such a leather-like sheet material, a fiber sheet material such as nonwoven fabric or web is impregnated with a polymer elastic body solution such as polyurethane, and then the fiber sheet material is immersed in water or an organic solvent aqueous solution. Thus, a method of wet coagulating the polymer elastic body is generally employed.

  However, since a large amount of polyurethane is used to obtain strength, dimensional stability, etc., the leather-like sheet-like material is expensive due to the raw material cost of polyurethane and the complicated manufacturing process. Further, when the amount of the polymer elastic body increases, it tends to have a rubber-like texture, and it becomes difficult to obtain a feeling of fulfillment similar to natural leather. Furthermore, water-miscible organic solvents such as N, N'-dimethylformamide are generally used for impregnating such polyurethane, but these organic solvents are generally not preferred from the viewpoint of the working environment.

  In recent years, recyclability has been emphasized for the purpose of protecting the environment and resources. For this reason, for example, a polyester decomposition and recovery method (for example, Patent Document 1) and a polyurethane decomposition method (for example, Patent Document 2) have been studied. ing. However, all of these methods are mainly applied to single-component materials, and in the case of composite materials in which the above-mentioned fibers and a polymer elastic body such as polyurethane are inseparably integrated, the decomposition methods are different, so that they should be applied. Is difficult. Therefore, although it is necessary to separate each component, it is generally very expensive and difficult to completely separate.

  Furthermore, it has been pointed out that polyurethane or the like is yellowed by NOx gas or the like, and it is difficult to obtain a white leather-like sheet.

  Therefore, a leather-like sheet-like material having a reduced or substantially free polymer elastic body such as polyurethane is desired. However, if a polymer elastic body such as polyurethane is reduced or eliminated, there is a problem that the physical properties, particularly the strength, of the leather-like sheet is lowered.

  Therefore, in order to solve this problem, it is an effective means to improve the strength of the nonwoven fabric (or web) itself that becomes the base material. As means for improving the strength of the nonwoven fabric (or web) itself, some have been studied so far. For example, a self-adhesive fiber bundle such as cellulose is formed, and then formed into a sheet by means such as needle punching, and then a high-speed fluid is sprayed onto the sheet, whereby fiber bundles, fiber bundles and single fibers, and single fibers are bonded together. A non-woven fabric for leather-like sheet-like material that is entangled and consists of a fiber bundle and a single fiber is disclosed (for example, Patent Document 3). However, when the fiber bundles are bonded by such a method, there are problems such as uneven color generation when dyeing, and deterioration of surface quality and texture. In addition, since a substantial part of the ultrafine fibers that are self-adhering by the high-speed fluid is peeled off and entangled, there is a problem in that the unevenness of the peeling occurs due to unevenness of adhesion, and the control thereof is difficult.

  On the other hand, various methods for improving entanglement have been proposed by performing high-speed fluid treatment after needle punching (for example, Patent Documents 4 and 5). This method is useful as a means for increasing the confounding efficiency of high-speed fluid processing. However, simply by combining the needle punching and high-speed fluid treatment, while maintaining the physical properties and quality such as to satisfy, it was found to be difficult to obtain a nonwoven fabric as it is possible to reduce the application amount of the polyurethane.

  As another means, needle punching is performed using low modulus polyester fiber and heat-shrinkable polyester fiber, followed by heat treatment and heat press treatment. It is disclosed that a base material for leather-like sheet-like material having the above can be obtained (for example, Patent Document 6). However, it has been found that when the nonwoven fabric obtained in this way is dyed by, for example, a liquid dyeing machine, blurring frequently occurs due to a stagnation action or the like.

Furthermore, there has been proposed a method of hydroentangling and integrating a structure in which a fabric having a high air permeability is inserted between layers of a plurality of papermaking webs using ultrafine single fibers. (For example, Patent Document 7) In this method, since the woven fabrics are laminated, there is no problem of tearing at the time of dyeing, but the abrasion resistance is insufficient when the surface of the product is rubbed.
WO01 / 30729 pamphlet JP 2001-348457 A JP 52-12902 A Japanese Patent Publication No. 1-18178 Japanese Patent Laid-Open No. 5-78986 Japanese Patent Publication No. 7-62301 Japanese Patent Laid-Open No. 7-109654

  The present invention is to provide an ultrafine short fiber nonwoven fabric having sufficient strength and a method for producing the same. Furthermore, even if it does not substantially contain a polymer elastic body such as polyurethane, it is a leather-like sheet material that can have sufficient quality, texture, physical properties, and is excellent in recyclability, yellowing resistance, etc. An ultrafine short fiber nonwoven fabric and a method for producing the same are provided.

In order to solve the above problems, the present invention mainly has the following configuration. That is, the ultrafine short fiber nonwoven fabric of the present invention includes ultrafine fibers having a single fiber fineness of less than 1 dtex, a basis weight of 100 to 550 g / m ² , a tensile strength of 70 N / cm or more, a tear strength of 3 to 50 N, and wear resistance. It is grade 3 or higher, and is essentially composed of a fiber material of an inelastic polymer.
Further, the leather-like sheet of the present invention contains ultrafine short fibers having a single fiber fineness of 0.0001 to 0.5 dtex, a basis weight of 100 to 550 g / m ² , a tensile strength of 70 N / cm or more, and a tear strength of 3 It is a leather-like sheet-like material characterized in that it has a wear resistance of 3 to 5 grades and is essentially composed of a dyed fiber material of an inelastic polymer.

Moreover, the manufacturing method of the ultra-thin short fiber nonwoven fabric of this invention is at least once in the web and / or nonwoven fabric with the basis weight of 100-550 g / m < ² > containing the ultra-fine fiber whose single fiber fineness is 0.0001-0.5 dtex. The high-speed fluid treatment is performed at a flow rate of 160 to 800 L / m ² .

Further, as another production method, a web and / or nonwoven fabric having a basis weight of 100 to 550 g / m ² including ultrafine fibers having a single fiber fineness of 0.0001 to 0.5 dtex is added to a total of 550 to 2000 L / m ² . A high-speed fluid treatment is performed at a flow rate.

Furthermore, as another production method, a web and / or nonwoven fabric having a basis weight of 100 to 550 g / m ² including ultrafine short fibers having a single fiber fineness of 0.0001 to 0.5 dtex is provided with a pore interval at least once. A high-speed fluid treatment is performed by a jet force of 0.16 to 1.60 N per hole from a nozzle arranged at 0.15 to 2.50 mm.

  ADVANTAGE OF THE INVENTION According to this invention, the ultra-short fiber nonwoven fabric excellent in the strength physical property especially suitable for the base fabric of a leather-like sheet-like material can be provided. Moreover, by using the above-mentioned ultrafine short fiber nonwoven fabric, the amount of polyurethane applied can be greatly reduced, or a high-quality leather-like sheet-like material can be provided without using it at all.

  Furthermore, according to the present invention, it is possible to obtain an ultra-fine short fiber nonwoven fabric that is a leather-like sheet-like material excellent in a sense of fulfillment that can be used for shoes, furniture, clothing, and the like.

  The ultrafine short fiber nonwoven fabric of the present invention comprises short fibers having a single fiber fineness of 0.0001 to 0.5 dtex. The single fiber fineness is more preferably 0.001 to 0.3 dtex, and further preferably 0.005 to 0.15 dtex. If it is less than 0.0001 dtex, the strength decreases, which is not preferable. On the other hand, if it exceeds 0.5 dtex, the texture becomes stiff, and entanglement becomes insufficient, resulting in problems such as deterioration in surface quality and wear resistance. Moreover, the fiber of the fineness exceeding said range may be contained in the range which does not impair the effect of this invention.

  The method for producing so-called ultrafine short fibers having a single fiber fineness in the above-mentioned range is not particularly limited. For example, a method of directly spinning ultrafine fibers, a fiber having ordinary fineness and capable of generating ultrafine fibers (extrafine fibers). There is a method in which an ultrafine fiber is generated by spinning an ultrafine fiber.

    And, as a method of using the ultrafine fiber generation type fiber, for example, the sea island type composite fiber is spun and then the sea component is removed, and the split type composite fiber is spun and then divided and made into ultrafine. can do. Among these, in the present invention, it is preferable to produce by using an island-in-sea type composite fiber or a split-type composite fiber in that an ultrafine fiber can be obtained easily and stably. It is more preferable to manufacture with a sea-island type composite fiber in that an ultrafine fiber made of the same kind of polymer that can be dyed with the same kind of dye can be easily obtained.

  The sea-island type composite fiber as used in the present invention refers to a fiber in which two or more components are combined and mixed at an arbitrary stage to form a sea-island state, and the method for obtaining this fiber is not particularly limited. ) A method of blending and spinning two or more components in a chip state, (2) A method of kneading a polymer of two or more components in advance to form a chip and then spinning, (3) A polymer of two or more components in a molten state And the like, and (4) a method of producing using a base such as Japanese Patent Publication No. 44-18369 and Japanese Patent Laid-Open No. 54-116417. In the present invention, any method can be used to satisfactorily produce, but the method (4) is preferably employed because the selection of the polymer is easy.

  In the method (4), the cross-sectional shape of the island fiber obtained by removing the sea-island type composite fiber and the sea component is not particularly limited, and for example, round, polygonal, Y, H, X, W, C, π type, etc. Is mentioned. Further, the number of polymer species to be used is not particularly limited, but it is preferably 2 to 3 components in consideration of spinning stability and dyeability, and particularly composed of 2 components of sea 1 component and island 1 component. It is preferable. The component ratio at this time is preferably 0.30 to 0.99, more preferably 0.40 to 0.97 in terms of weight ratio of island fibers to sea-island composite fibers, and 0.50 to 0.80. Is more preferable. If it is less than 0.30, the removal rate of sea components increases, which is not preferable in terms of cost. On the other hand, if it exceeds 0.99, the island components are likely to merge with each other, which is not preferable in terms of spinning stability.

  In addition, the polymer to be used is not particularly limited, and for example, polyester, polyamide, polypropylene, polyethylene, etc. can be used as an island component depending on the use, but in terms of dyeability, strength, durability, and fastness. Polyester is preferable.

  The polyester that can be used in the present invention is a polymer that is synthesized from a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof, and is particularly limited as long as it can be used as a composite fiber. Is not to be done. Specifically, for example, polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, polyethylene-1,2-bis (2- Chlorophenoxy) ethane-4,4′-dicarboxylate and the like. In the present invention, polyethylene terephthalate, which is most commonly used, or a polyester copolymer mainly containing ethylene terephthalate units is preferably used.

  The polymer used as the sea component of the sea-island composite fiber is not particularly limited as long as it has chemical properties that are higher in solubility and degradability than the polymer constituting the island component. Depending on the selection of polymer constituting the island component, for example, polyolefins such as polyethylene and polystyrene, 5-sodium sulfoisophthalic acid, polyethylene glycol, sodium dodecylbenzenesulfonate, bisphenol A compound, isophthalic acid, adipic acid, Dodekajion acid, Polyester etc. which copolymerized cyclohexyl carboxylic acid etc. can be used. Polystyrene is preferable from the viewpoint of spinning stability, but a copolymer polyester having a sulfone group is preferable because it can be easily removed without using an organic solvent. The copolymerization ratio is preferably 5 mol% or more from the viewpoint of processing speed and stability, and 20 mol% or less from the viewpoint of ease of polymerization, spinning and stretching. A preferred combination in the present invention is a copolyester having polyester as the island component and polystyrene or sulfone group as the sea component.

  To these polymers, inorganic particles such as titanium oxide particles may be added to the polymer in order to improve the concealing property. In addition, lubricants, pigments, heat stabilizers, ultraviolet absorbers, conductive agents, heat storages, etc. An agent, an antibacterial agent and the like can be added according to various purposes.

  Further, the method for obtaining the sea-island type composite fiber is not particularly limited. For example, after taking the undrawn yarn using the die shown in the above method (4), the wet-heat or dry heat, or both of them are 1 to 3 It can be obtained by step stretching.

  In addition, when using split type composite fiber, it can mainly carry out according to the manufacturing method of the above-mentioned sea-island type composite fiber by compounding two or more components in the die.

    As a method for obtaining an ultra-fine short fiber nonwoven fabric, the above-mentioned fiber needs to be cut to an appropriate length, and is preferably 100 mm or less in consideration of productivity and the texture of the obtained product. More preferably, it is 70 mm or less. A fiber length exceeding 100 mm may be included as long as the effects of the present invention are not impaired. Further, the lower limit is not particularly limited and can be appropriately set depending on the method of manufacturing the nonwoven fabric. However, if the length is less than 10 mm, dropout tends to increase, and properties such as strength and wear resistance tend to decrease. Therefore, the fiber length is 10 mm or more. It is preferable to do.

  A method preferably used as a method for obtaining such a fiber is a method in which an undrawn yarn obtained directly or as a composite fiber is drawn and then shortened with a rotary cutter or a guillotine cutter.

  As a method for producing the ultrafine short fiber nonwoven fabric of the present invention, a method in which needle punching and high-speed fluid treatment are combined is preferably employed. That is, the web is subjected to both needle punch processing and high-speed fluid processing. The short fibers as a way of webs of the card and cross wrapper, and a dry method which can use a random Weber, can be employed a wet process by paper making method, etc., in the present invention, needle-punched and high velocity fluid treatment A dry method that can easily combine these two types of entanglement treatment is preferred. During entangling treatment, moderate growth or for imparting elongation blind or the resulting nonwoven fabric other fabrics in order to improve the physical properties such as strength of, knitting, it may be integrated with the nonwoven fabric.

Next, the basis weight of the ultra-fine short fiber nonwoven fabric of the present invention is 100 to 550 g / m ² . Basis weight is preferably 120~450g / ^{m 2,} and more preferably 140~350g / ^{m 2.} If it is less than 100 g / m ² , the physical properties of the nonwoven fabric structure alone are lowered, and when the woven fabric and / or the knitted fabric are laminated, the appearance of the woven fabric and / or the knitted fabric is easily visible on the surface, and the quality is lowered. Therefore, it is not preferable. On the other hand, if it exceeds 550 g / m ² , the wear resistance tends to decrease, which is not preferable. The fiber apparent density is preferably 0.300~0.600g / cm ^3, further preferably 0.330~0.500g / cm ^3. If it is less than 0.28 g / cm ³ , tearing or stroking may occur when dyeing is performed, and it will be difficult to obtain sufficient strength and wear resistance. When it exceeds 0.600 g / cm ³ , a paper-like texture is obtained, which is not preferable.

  In addition, the fiber apparent density measured the basis weight according to JIS L1096 8.4.2 (1999), then measured the thickness thereof, and the average value of the fiber apparent density obtained therefrom was used as the fiber apparent density. The thickness was measured using a dial thickness gauge (manufactured by Ozaki Mfg. Co., Ltd., trade name “Peacock H”), 10 samples were measured, and the average value was used. The fiber apparent density in the present invention refers to the apparent density of the fiber material. Therefore, for example, in the case of a nonwoven fabric structure impregnated with a resin other than the fiber material, the apparent density of the fiber material excluding the resin is shown.

  Further, ultra-fine staple fiber nonwoven fabric of the present invention is the tensile of any longitudinal and transverse directions potent 70N / cm or more. It is preferable that the tensile strength in both the vertical and horizontal directions is 80 N / cm or more. If the tensile strength in either the vertical or horizontal direction is less than 70 N / cm, for example, when a leather-like sheet-like material is used, the process passability in the next high-order processing step is deteriorated, and tearing, dimensional change, etc. occur. Since there is a tendency, it is not preferable. In addition, when a leather-like sheet is used, there is a problem that a large amount of polyurethane needs to be applied in order to obtain sufficient physical properties. In addition, although an upper limit is not specifically limited, Usually, it will be 200 N / cm or less. The tensile strength is JIS L 1096 8.12.1 (1999), samples were taken width 5 cm, length 20 cm, at a constant extension rate type tensile tester at a gripping distance 10 cm, elongated at a tensile rate of 10 cm / min I asked for it. From the obtained value, the load per 1 cm width was defined as tensile strength (unit: N / cm). In order to obtain these strengths, the strength of the fibers used is preferably 2 cN / dtex or more.

  Furthermore, it is preferable that the ultra-fine short fiber nonwoven fabric of the present invention has a tear strength in the vertical and horizontal directions of 5 to 30N. When the tearing strength in either the vertical or horizontal direction is less than 3N, the process passability is lowered and stable production becomes difficult. On the other hand, if the tearing strength in either the vertical or horizontal direction exceeds 50 N, it generally tends to be too soft and it is difficult to balance the texture. The tear strength was measured based on JIS L 1096 8.15.1 (1999) D method (pendulum method).

  In order to obtain these tear strengths, it can be achieved by adjusting the apparent fiber density of the ultra-fine short fiber nonwoven fabric to an appropriate range. Generally, when the density is increased, the strength tends to decrease.

  In order to prevent deformation and tearing of the sheet in the post-process that is further performed according to the use, the ultra-fine short fiber nonwoven fabric of the present invention preferably has a 10% modulus in the vertical direction of 8 N / cm or more, and is 10 N / cm. It is more preferable. The upper limit is not particularly limited, but if it exceeds 50 N / cm, the texture is hardened and workability is lowered, which is not preferable. In the case of manufacturing by the above-described manufacturing method, the value of 10% modulus can be improved by sufficiently performing needle punch processing or high-speed fluid processing. It can also be increased by laminating woven and / or knitted fabrics.

  In addition, these values are naturally reduced by performing a dyeing treatment or a stagnation treatment, but at the stage of the ultrafine short fiber nonwoven fabric before performing these treatments, being within the scope of the present invention, a better process pass It is possible to easily obtain a leather-like sheet material having good quality and quality.

  The 10% modulus was measured in the same manner as the tensile strength measurement method, and the strength at 10% elongation was taken as the value.

    Ultra-fine staple fiber nonwoven fabric of the present invention, the abrasion test measured according to JIS L 1096 (1999) 8.17.5 E method (Martindale method) Furniture load (12 kPa), 3000 times and 20000 times The surface appearance of the test cloth after the number of wears is 3 to 5 in the judgment criteria table of JIS L 1076 (1999) Table 2. Both 3000 times and 20000 times are preferably 3.5 to 5 grade, more preferably 4 to 5 grade. If it is less than the third grade, sufficient quality cannot be maintained, and the fifth grade is the most preferable state for evaluation. Conventionally, leather-like sheet-like materials have been evaluated as the number of times until the fabric layer is exposed as described in Japanese Patent Application Laid-Open No. 2003-268680 as an end point on appearance. However, in the case where dings and pills are generated even when the fabric layer is not exposed, there is a problem that the number of times until the fabric layer is exposed does not necessarily match the durability of the surface. Therefore, the abrasion resistance evaluation of the present invention using the criterion table of JIS L 1076 (1999) Table 2, assuming a 3000 times and long-term after use and the change in appearance such as the presence or absence of pilling assumed after short-term use It is evaluated at 20000 times. In particular, it is important to show the stability of the form that the appearance does not change significantly after 20000 times, but the appearance change may be large in short-term use. Therefore, in the present invention, a higher level of durability can be achieved by no change even after 3000 times. Further, the abrasion test measured according to JIS L 1096 (1999) 8.17.5 E method (Martindale method) Furniture load (12 kPa), abrasion loss is preferably from 20mg after 20000 times, 15 mg The following is more preferable, and 10 mg or less is more preferable. When the wear loss exceeds 20 mg, fluff tends to adhere to clothes and the like in actual use, which is not preferable. Meanwhile lower limit is not particularly limited, and can be obtained. However things have little abrasion loss if the leather-like sheet of the present invention.

    Moreover, since the ultra-fine short fiber nonwoven fabric of the present invention has high physical properties and a dense structure, it can be applied to abrasive cloths, filters, wipers, heat insulating materials, sound absorbing materials, etc. in addition to leather-like sheet-like materials. Can do.

    The ultra-fine short fiber non-woven fabric of the present invention is substantially free of a polymer elastic body such as polyurethane and is substantially made of a non-elastic polymer fiber material.

    The term “substantially made of fiber material” as used herein means that the binder made of a polymer elastic body such as polyurethane is less than 5% by weight based on the fiber, preferably the binder is less than 3% by weight based on the fiber. More preferably, the binder is less than 1% by weight with respect to the fiber, and most preferably the binder is not included.

    The fiber of non-elastic polymer here means a polymer excluding fibers excellent in rubber-like elasticity such as polyether-based fibers and polyurethane fibers such as so-called spandex. Specific examples include fibers made of polyester, polyamide, polypropylene, polyethylene and the like. A polymer constituting the ultrafine short fiber nonwoven fabric described above is suitable. By consisting essentially of non-elastic polymer fiber material, it is possible to achieve the texture of fullness without rubber feel. Also, further, easy recyclability, high color developability, high light resistance, various effects such as yellowing resistance can be achieved. In particular, in order to perform the chemical recycling is preferably one fiber material made of polyethylene terephthalate or nylon 6. The ultra-fine short fiber nonwoven fabric of the present invention is most preferably one that does not contain any elastic polymer such as polyether ester fiber or polyurethane fiber such as spandex. However, the polymer is not deviated from the effect of the present invention. An elastic body may be included. In addition, functional agents such as dyes, softeners, texture modifiers, pilling inhibitors, antibacterial agents, deodorants, water repellents, light proofing agents, and antifungal agents may be included.

The leather-like sheet material of the present invention is composed of the ultrafine short fiber nonwoven fabric of the present invention, and is formed by dyeing the ultrafine short fiber nonwoven fabric of the present invention. In addition, it includes an ultrafine short fiber having a single fiber fineness of 0.0001 to 0.5 dtex, substantially made of a dyed fiber material of an inelastic polymer, a basis weight of 100 to 550 g / m ² , and a tensile strength of 70 N / cm or more. It is a leather-like sheet having a tear strength of 3 to 50 N and an abrasion resistance of 3 to 5.

    The leather-like sheet here means a material having an excellent surface appearance such as suede, nubuck, silver surface, etc. like natural leather, and particularly preferred in the present invention is napped texture such as suede or nubuck. In appearance, it has a smooth touch and excellent lighting effects. Generally, a leather-like sheet material called synthetic leather or artificial leather is composed of a polymer elastic body such as polyurethane and a fiber material, but one embodiment of the leather-like sheet material of the present invention is substantially made of polyurethane or the like. It does not include a polymer elastic body and is substantially made of a non-elastic polymer fiber material.

    Also in the leather-like sheet-like material of the present invention, the material substantially composed of a fiber material means that the binder composed of a polymer elastic body such as polyurethane is less than 5% by weight, preferably the binder. less than 3% by weight relative to the fiber, more preferably less than 1% by weight binder with respect to the fiber, most preferably it does not contain a binder.

    The fiber of non-elastic polymer here means a polymer excluding fibers excellent in rubber-like elasticity such as polyether-based fibers and polyurethane fibers such as so-called spandex. Specific examples include fibers made of polyester, polyamide, polypropylene, polyethylene and the like. A polymer constituting the ultrafine short fiber nonwoven fabric described above is suitable. By being made of a substantially non-elastic polymer fiber material, it is possible to achieve a texture with a sense of fullness without rubber feeling. Furthermore, various effects such as easy recyclability, high color developability, high light resistance, yellowing resistance, and the like can be achieved. In particular, in order to perform chemical recycling, the fiber material is preferably made of polyethylene terephthalate or nylon 6. It is most preferable that one embodiment of the leather-like sheet of the present invention does not contain any polymer elastic body such as polyether-based fibers and polyurethane-based fibers such as spandex, but does not depart from the effects of the present invention. A polymer elastic body may be included in the range. In addition, functional agents such as dyes, softeners, texture modifiers, pilling inhibitors, antibacterial agents, deodorants, water repellents, light proofing agents, and antifungal agents may be included.

    The method for measuring the single fiber fineness, basis weight, tensile strength, tear strength, and abrasion resistance of the leather-like sheet of the present invention is the same as that for the ultra-fine short fiber nonwoven fabric.

    Further, it the fiber material constituting the leather-like sheet contains fine particles is preferable in view of excellent abrasion resistance. In particular, it is more preferable that the ultrafine fibers of the fiber material are intertwined with each other, and a large effect of improving wear resistance can be obtained by the presence of fine particles.

  The material of the fine particles here is not particularly limited as long as it is insoluble in water, and examples thereof include inorganic substances such as silica, titanium oxide, aluminum and mica, and organic substances such as melamine resin. The average particle diameter of the fine particles is preferably 0.001～30Myuemu, more preferably 0.01 to 20 .mu.m, more preferably from 0.05 to 10 [mu] m. When the thickness is less than 0.001 μm, it is difficult to obtain the expected effect, and when it exceeds 30 μm, the washing durability decreases due to dropping off from the fiber. Note the average particle size can be measured using the measurement method suitable depending on the material and size, for example, BET method, laser method, a Coulter method.

    The amount of these fine particles can be appropriately adjusted within a range in which the effect of the present invention can be exhibited, but is preferably 0.01 to 10% by weight, more preferably 0.02 to 5% by weight, and still more preferably. Is 0.05 to 1% by weight. If it is 0.01 weight% or more, the improvement effect of abrasion resistance can be exhibited notably, and the effect tends to become large, so that the amount is increased. However, if it exceeds 10% by weight, the texture becomes hard, which is not preferable. Incidentally, to prevent falling off of the fine particles, in order to improve the durability, preferably in combination with small amounts of resin.

    Further, in order to obtain a soft texture and a smooth surface touch, the leather-like sheet of the present invention preferably contains a softening agent. Is not particularly limited as softeners, those commonly used in the woven or knitted fabric appropriately selected depending on the fiber type. For example, in the 23rd edition of Dyeing Note (Issue Color Co., Ltd., issued on August 31, 2002), those described under the names of texture finish and soft finish can be appropriately selected. Among these, a silicone emulsion is preferable in terms of excellent flexibility effect, and an amino-modified or epoxy-modified silicone emulsion is more preferable. When these softeners are included, the wear resistance tends to decrease. Therefore, the amount of the softener and the amount of the fine particles can be appropriately adjusted while balancing the target texture and the wear resistance. preferable. Therefore, the amount is not particularly limited, but if it is too small, the effect cannot be exhibited, and if it is too large, there is a feeling of stickiness, so a range of 0.01 to 10% by weight is preferable.

  Next, an example of a method for producing the ultrafine short fiber nonwoven fabric of the present invention will be described.

    The ultrafine short fiber nonwoven fabric comprises short fibers having a single fiber fineness of 0.0001 to 0.5 dtex, but the method for producing so-called ultrafine short fibers in which the single fiber fineness is in the above range is particularly limited. For example, there are a method of directly spinning ultrafine fibers, a method of spinning fibers (ultrafine fiber generation type fibers) which are usually fine fibers and can generate ultrafine fibers, and then generate ultrafine fibers. And, as a method of using the ultrafine fiber generation type fiber, for example, the sea island type composite fiber is spun and then the sea component is removed, and the split type composite fiber is spun and then divided and made into ultrafine. can do.

  Ultrafine preferred for obtaining short-fiber nonwoven fabric process of the present invention is to produce a web with a microfine fiber-forming fibers of 1～10Dtex, the web is a composite staple fiber nonwoven fabric by needle punching, and then the above least 10MPa High pressure fluid processing with pressure, for example, water jet punching with water flow. After that, miniaturization is performed. By combining this needle punch process and high-speed fluid process, it is possible to highly entangle ultrafine short fibers.

  Ultra-fine staple fiber nonwoven fabric in the present invention have excellent but in order to obtain the quality and texture is to a short-fiber nonwoven fabric, in view of the texture of productivity and to obtain what the aspect ratio of the ultrafine short fibers 5,000 ~ 900,000 is preferred. The aspect ratio here is a value obtained by dividing the fiber length by the fiber diameter, preferably 10,000 to 500,000, and more preferably 20,000 to 50,000. If the aspect ratio is less than 5,000, the dropout tends to increase, and the properties such as strength and wear resistance tend to decrease. If the aspect ratio exceeds 900,000, the number of fibers decreases, and the uniformity tends to be impaired. Further, in the high-speed fluid treatment described later, the aspect ratio of the entangled and caught per number of fibers is reduced is less than 5,000, more easily form the high pressure treatment is destroyed, if it exceeds 900,000, the water pressure necessary for confounding This is economically disadvantageous because the amount of water increases.

  The aspect ratio referred to in the present invention can be obtained by directly measuring the length and diameter of the ultrafine fibers extracted from the ultrafine short fiber nonwoven fabric. Note that the diameter of the circumscribed circle is used when the cross section is not a circle.

The composite short fiber nonwoven fabric preferably has an apparent fiber density of 0.120 to 0.300 g / cm ³ , more preferably 0.150 to 0.250 g / cm ³ by needle punching. If it is less than 0.120 g / cm ³ , the entanglement will be insufficient and the desired physical properties will be difficult to obtain. The upper limit is not particularly defined, but if it exceeds 0.300 g / cm ³ , problems such as breakage of the needle needle and remaining of the needle hole are not preferable.

  Moreover, when performing needle punching, it is preferable that the single fiber fineness of a composite fiber is 1-10 dtex, 2-8 dtex is more preferable, 2-6 dtex is further more preferable. When the single fiber fineness is less than 1 dtex or exceeds 10 dtex, the entanglement by the needle punch becomes insufficient, and it becomes difficult to obtain an ultra-fine short fiber nonwoven fabric with good physical properties.

In the needle punch according to the present invention, it is preferable that the fibers are sufficiently entangled rather than merely serving as temporary fixing for obtaining process passability. Therefore, the driving density is preferably 100 / cm ² or more, more preferably 500 / cm ² or more, and still more preferably 1000 / cm ² or more.

  The composite short fiber nonwoven fabric thus obtained is preferably shrunk by dry heat and / or wet heat, and further densified.

  Next, the high-speed fluid treatment is performed. The high-speed fluid treatment is preferably performed after the ultrafine treatment, simultaneously with the ultrafine treatment, or simultaneously with and after the ultrafine treatment, and entangle the ultrafine fibers. Although it is possible to combine high-speed fluid treatment with ultrafine treatment, it is preferable to perform high-speed fluid treatment even after at least most of the ultrafine treatment is completed, in order to further promote the entanglement between ultrafine fibers, It is preferable to perform high-speed fluid processing after performing ultrafine processing.

  The ultrafine treatment method is not particularly limited, and examples thereof include a mechanical method and a chemical method. The mechanical method is a method of miniaturization by applying a physical stimulus, for example, a method of applying pressure between rollers in addition to the method of giving an impact such as the needle punch method or the water jet punch method described above, Examples include a method of performing ultrasonic treatment. The chemical method includes, for example, a method in which at least one component constituting the composite fiber is subjected to changes such as swelling, decomposition, and dissolution by a drug. In particular, a method for producing a composite short fiber nonwoven fabric with ultrafine fiber-generating fibers using an alkali-degradable sea component and then treating it with a neutral-alkaline aqueous solution to make it ultrafine is based on the working environment without using a solvent. Since it is preferable, it is one of the preferable embodiments of the present invention. The neutral to alkaline aqueous solution here is an aqueous solution having a pH of 6 to 14, and the chemicals used are not particularly limited. For example, an aqueous solution containing organic or inorganic salts may be used as long as it exhibits a pH in the above range, and alkali metal salts such as sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, sodium bicarbonate, calcium hydroxide, water Examples include alkaline earth metal salts such as magnesium oxide. Further, if necessary, amines such as triethanolamine, diethanolamine, monoethanolamine, a weight loss accelerator, a carrier, and the like can be used in combination. Of these, sodium hydroxide is preferable in terms of price and ease of handling. Furthermore, it is preferable that the sheet is subjected to the neutral to alkaline aqueous solution treatment described above, and then neutralized and washed as necessary to remove the remaining chemicals and decomposition products, and then dried.

  As a method of simultaneously performing these ultrafine processing and high-speed fluid processing, for example, using a composite fiber composed of a water-soluble sea component, removing and entanglement by water jet punch, two or more components having different alkali decomposition rates Examples include a method in which a composite fiber is used to decompose an easily soluble component through an alkali treatment liquid and then subjected to final removal and entanglement treatment by a water jet punch.

  In the present invention, it is preferable to add a form stabilizer for the purpose of improving the form stability of the web and / or nonwoven fabric during high-speed fluid processing. In particular, it is preferable to apply a water-soluble form stabilizer to the web or non-woven fabric before and after the ultrafine treatment, and to remove the non-woven fabric when the shape is stabilized by a water jet punch process described later. As such a water-soluble form stabilizer, organic substances such as polyvinyl alcohol or derivatives thereof, water-soluble starch, carboxymethyl cellulose, partially saponified acrylate ester, polyacrylamide, and cellulose acetate are preferable. These water-soluble form stabilizers are applied to webs and non-woven fabrics as aqueous solutions or emulsions, but for the application treatment of aqueous solutions or emulsions of form stabilizers, those subjected to impregnation method, spray method, coating method, etc. are dried by heat. It can be processed by a conventional method such as a coagulation method, a wet coagulation method with water or the like, and an appropriate steam treatment. If the applied amount is too small, it will be difficult to maintain the form and function, and if it is too large, the effect of the water jet punching process will be hindered and the entanglement of the ultrafine fibers will be difficult to proceed. 3 to 60% by weight is preferable, and 5 to 40% by weight is more preferable.

    As the high-speed fluid processing, it is preferable to perform water jet punch processing using a water flow in terms of the working environment. At this time, it is preferable to perform the water in a columnar flow state. To obtain a columnar flow, usually obtained by jetting at a pressure 1~60MPa from diameter holes 0.06～1.0Mm.

The high-speed fluid processing of the present invention has three main modes. The first aspect is an aspect implemented at least once with a water amount of 160 to 800 L / m ² , the second aspect is an aspect performed with a total water amount of 550 to 2000 L / m ² , and the third aspect is at least One time is a mode in which the nozzle spacing is 0.15 to 2.50 mm and the jet force is 0.16 to 1.60 N per hole. In particular, in order to ensure sufficient strength and wear resistance, the flow rate used in high-speed fluid processing is one of the important factors, and the first and second modes achieve this flow rate. Jet force is also an important factor, and the third aspect achieves this.

    These three modes may be implemented in any mode, but may be combined. In addition, the third aspect is particularly preferable because the processing speed can be easily increased and the energy required for processing can be reduced.

The first aspect of the high-speed fluid processing of the present invention will be described in detail. In order to obtain efficient entanglement and good surface quality, the treatment preferably has a pore diameter of 0.06 to 0.15 mm and an interval of 5 mm or less, and a pore diameter of 0.06 to 0.12 mm and an interval. Is more preferably 1 mm or less. When these hole specifications are processed a plurality of times, it is not necessary to make them all the same. For example, a nozzle having a large hole diameter and a small hole diameter can be used in combination, but the nozzle having the above configuration is used at least once. It is preferable. In particular, a large hole interval is not preferable because striking marks imparted to the sheet by the water flow are conspicuous and confounding does not proceed in the untreated part. Moreover, when the diameter exceeds 0.15 mm and the hole interval is reduced as described above, the amount of water discharged in one treatment when treated at the same pressure increases, and the water stays without passing through the nonwoven fabric or the support. It is not preferable because water is easily generated and the effect of the water jet is remarkably lowered by the staying water, so that the entanglement property between the ultrafine fibers is difficult to be increased, the surface is easily smoked, and the surface smoothness is also reduced. Therefore, a smaller pore diameter is preferred, but if it is less than 0.06 mm, clogging of the pores is likely to occur. Further, for the purpose of achieving uniform entanglement in the thickness direction and / or improving the smoothness of the nonwoven fabric surface, the treatment is preferably repeated a number of times. Further, the water flow pressure is appropriately selected according to the basis weight of the nonwoven fabric to be treated, and the higher the basis weight, the higher the pressure. Such high-speed fluid processing needs to be performed at a flow rate of 160 to 800 L / m ² at least once. 210-750 L / m < ² > is more preferable, and 260-700 L / m < ² > is further more preferable. If the flow rate is less than 160 L / m ² , sufficient entanglement cannot be obtained, and peaching may occur in the dyeing process, or the wear resistance of the product will be insufficient. On the other hand, when the flow rate exceeds 800 L / m ² , uniform processing becomes difficult, and tearing tends to occur during the processing.

The second aspect of the high-speed fluid processing of the present invention will be described in detail. Such treatment is also preferably performed with the same hole diameter and hole interval as in the first embodiment. The total flow rate needs to be in the range of 550 to 2000 L / m ² . 600-1950 L / m < ² > is more preferable, and 650-1900 L / m < ² > is further more preferable. Is less than 550L / ^{m 2} is difficult to process strongly the entire sheet is not preferable because cost increases exceeds 2000L / ^{m 2.}

    The third aspect of the high-speed fluid processing of the present invention will be described in detail. In this treatment, at least once, the high-speed fluid treatment is performed with a jet force of 0.16 to 1.60 N per hole from a nozzle arranged with a hole interval of 0.15 to 2.50 mm. The hole interval is 0.20 to 2.00 mm, the jet force per hole is more preferably 0.18 to 1.50 N, the hole interval is 0.25 to 1.50 mm, and the jet force per hole is 0.20. ˜1.40 N is more preferable. In order to obtain the necessary jet force when the hole interval is less than 0.15 mm, the amount of water discharged in one process is large, and water that does not pass through the nonwoven fabric or the support tends to be generated. This is because the effect of the water jet is remarkably reduced, and when the hole interval exceeds 2.50 mm, striking marks imparted to the sheet by the water flow are conspicuous and confounding does not proceed in the untreated part. Further, if the jet force per hole is less than 0.16N, sufficient entanglement cannot be obtained, and the wear resistance of the product tends to be insufficient, and if the jet force per hole exceeds 1.60 N, a nonwoven fabric or a support. It is not preferable because water that cannot pass through the water tends to be generated, and the water jet effect is remarkably lowered by the staying water and uniform treatment becomes difficult. Since such a jet force can be easily obtained by setting a relatively large hole diameter, the hole diameter of the third aspect is preferably 0.08 to 0.25 mm, and more preferably 0.10 to 0.20 mm.

    The times referred to in these three aspects means the number of times of passing through one nozzle plate having holes aligned in a direction not parallel to the conveyor and / or cylinder to be conveyed. Also refers to a large range. If the hole diameter is larger than the hole interval by arranging the holes in a plurality of rows, the value obtained by dividing the hole interval by the hole diameter is the number of times, and the flow rate is repeated to obtain the flow rate per number of times. Moreover, the total flow rate as used in the field of this invention means the sum of the flow rates when it is repeatedly processed many times.

    As means for obtaining such a flow rate, the hole diameter, the hole interval, the water pressure in the chamber, and the conveyance speed of the nonwoven fabric are adjusted. Further, the flow rate is calculated according to the following equation, with the hole diameter being the fluid discharge diameter.

Q: Flow rate per pass (L / m ² )
di: Hole diameter (mm)
Pg: Water pressure (MPa)
p: hole interval (mm)
s: Conveying speed (m / min)
The jet force per hole is determined according to the following equation, with the hole diameter being the fluid discharge diameter, as with the flow rate.

F: Jet force per hole (N)
Note that the fluid immersion treatment may be performed before the high-speed fluid treatment is performed on the composite short fiber nonwoven fabric or the ultrafine short fiber nonwoven fabric. Furthermore, in order to improve the surface quality, it is possible to move the nozzle head and the nonwoven fabric relatively, or insert a wire mesh between the nonwoven fabric and the nozzle after entanglement to perform watering treatment. In this way, the ultrafine fibers are preferably entangled until the 10% modulus in the vertical direction is 8 N / cm or more, more preferably 10 N / cm or more.

    In general, the case of ultrafine fibers obtained from conjugate fibers, but microfine fiber bundles fibers have focused are mainly entangled, by such process, according to microfine fiber bundles in the ultra-fine staple fiber nonwoven fabric of the present invention It is possible to obtain an ultra-fine short fiber nonwoven fabric in which ultra-fine fibers are highly entangled to such an extent that entanglement is hardly observed, thereby improving surface characteristics such as wear resistance.

  The manufacturing method of the ultra-thin short fiber nonwoven fabric of the present invention can be easily achieved by the above-described process, particularly from the difference between the fiber that is easily entangled by needle punching and the fiber that is easily entangled by high-speed fluid treatment. The excellent ultrafine short fiber nonwoven fabric of the present invention is obtained. That is, in the fibers thick state of 1~10dtex excellent entanglement by needle punching, in the ultrafine region of 0.0001~0.5dtex is obtained by utilizing the fact that there is a tendency that excellent is entangled by high velocity fluid treatment. To combine these fiber fineness and entangling methods, allowed to sufficiently entangled by needle punching using microfine fiber-forming composite fibers having a fineness 1～10Dtex, then superfine to obtain ultrafine fibers of 0.0001~0.5dtex reduction after treatment was, or microfine treatment and simultaneously or simultaneously and then the microfine treatment, it is preferable to perform the high-speed fluid treatment.

  Next, the manufacturing method of the leather-like sheet material of this invention is demonstrated.

  The leather-like sheet-like material of the present invention is obtained by dyeing at least the ultra-fine short fiber nonwoven fabric of the present invention, and this makes it possible to obtain a leather-like texture. In addition, as long as it contains the ultra-fine short fiber nonwoven fabric of the present invention, it may contain a woven or knitted fabric, etc., but it is difficult to obtain a good texture if it consists only of woven or knitted fabric. Become.

  Lamination of the woven or knitted fabric and the ultra-fine short fiber nonwoven fabric can be achieved by stacking them before the needle punching process or the high-speed fluid processing process, and entanglement and integration by each processing. At this time, the needle punching step and the high-speed fluid treatment step may be performed. However, since the fibers constituting the woven or knitted fabric are not easily cut, lamination by entanglement integration in the high-speed fluid treatment is preferable.

  In addition, the leather-like sheet material may be either a silvery tone or a nap tone, but if it is made of only a fiber material, it is particularly possible to obtain a better surface quality with a nap tone, so at least It is preferable that one surface is raised. In the case of obtaining a silver-tone surface, a method of forming an ultra-high density fiber layer on the surface is preferable, unlike the conventional method of forming a resin layer such as polyurethane. The leather-like sheet material of the present invention is substantially made of a fiber material, but has a surface quality similar to that of general natural leather or artificial leather, unlike a simple nonwoven fabric.

  And it is preferable that such a leather-like sheet is dyed.

  Method for dyeing the extremely fine short fiber nonwoven fabric is not particularly limited, as dyeing machine used, other liquid flow dyeing machine, thermosol dyeing machine, may be either a high-pressure jigger dyeing machine or the like, resulting leather-like sheet Dyeing with a liquid dyeing machine is preferred in that the texture of the product is excellent.

  Furthermore, when a suede-like or nubuck-like leather-like sheet-like material is obtained, it is preferable to perform a raising process with a sandpaper or a brush. Such raising treatment can be performed before or after dyeing, or before and after dyeing. Further, the method of performing the raising treatment after the above-described compression treatment is preferable because the wear resistance is improved.

  The method for producing a leather-like sheet of the present invention preferably includes a step of imparting fine particles to the fiber material for the purpose of improving wear resistance. By imparting fine particles to the fiber material, it is also possible to obtain an effect of giving a feel such as a dry feeling or a squeaky feeling. The fine particles to be used are as described above, but the means for applying the fine particles is not particularly limited, in addition to the pad method, a method using a liquid dyeing machine or a jigger dyeing machine, a method of spraying, etc. It can be selected appropriately.

    It is also preferable to include a step of applying a softening agent to the fiber material in order to obtain a soft texture and a smooth surface touch. The softening agent to be used is as described above, but the means for applying the softening agent is not particularly limited, and in addition to the pad method, a method using a liquid flow dyeing machine or a jigger dyeing machine, a spraying method, or the like is used. Can do. From the viewpoint of production cost, it is preferable to apply it at the same time as the fine particles.

  The fine particles and softening agent are preferably applied after dyeing. If applied before dyeing, the effect may be reduced due to omission during dyeing or uneven dyeing may occur, which is not preferable. Moreover, since the nonwoven fabric containing microparticles | fine-particles has a tendency which is not raised easily, when raising, it is preferable to provide fine particles after raising.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the physical-property value in an Example was measured by the method described below.

(1) Weight per unit area and fiber apparent density The basis weight was measured by the method of JIS L 1096 8.4.2 (1999). Further, the thickness was measured with a dial thickness gauge (manufactured by Ozaki Mfg. Co., Ltd., trade name “Peacock H”), and the apparent fiber density was calculated from the basis weight value.

(2) Aspect ratio The fiber diameter (D) and fiber length (L) of 50 fibers randomly drawn from the sheet are measured, and the largest value of the ratio (L / D) is the ultra-fine short fiber nonwoven fabric. Of aspect ratio.

(3) Tensile strength According to JIS L 1096 8.12.1 (1999), a sample having a width of 5 cm and a length of 20 cm was taken, and a tensile speed of 10 cm / min was obtained with a constant-speed extension type tensile tester at a gripping interval of 10 cm. And stretched. The obtained value was converted to the tensile strength per 1 cm width.

(4) Tear strength Measured based on JIS L 1096 8.15.1 (1999) D method (penjuram method).

(5) Martindale abrasion test JIS L 1096 (1999) 8.17.5 E method (Martindale method) In the abrasion resistance test measured according to furniture load (12 kPa), the number of times was 3000 times and 20000 times. The weight loss of the test cloth after abrasion was evaluated, and the grade was judged from the appearance according to the judgment standard table of JIS L 1076 Table 2.

Example 1
A web was prepared through a card and a cross wrapper using a sea-island composite short fiber having a single fiber fineness of 3 dtex, 36 islands, and a fiber length of 51 mm, comprising 50 parts of polystyrene as a sea component and 50 parts of polyethylene terephthalate as an island component. Next, needle punching was performed with a 1 barb-type needle at a density of 2500 fibers / cm ² to obtain a composite short fiber nonwoven fabric with an apparent fiber density of 0.210 g / cm ³ . Next, it is immersed in an aqueous solution of 12% polyvinyl alcohol having a polymerization degree of 500 and a saponification degree of 88% heated to about 95 ° C. so as to give an adhesion amount of 25% with respect to the weight of the nonwoven fabric in terms of solid content. Thereafter, shrinkage treatment was carried out for 2 minutes simultaneously with the impregnation of PVA), followed by drying at 100 ° C. to remove moisture. The obtained sheet was treated with trichrene at about 30 ° C. until the polystyrene was completely removed to obtain ultrafine fibers having a single fiber fineness of about 0.042 dtex. Next, the water jet punch having a nozzle diameter of 0.1 mm and a nozzle head with a spacing of 0.2 mm was processed at 10 MPa and 20 MPa on the front and back surfaces at a processing speed of 1 m / min (total of 4 times). I went together. In addition, the side view of the used high-speed fluid processing apparatus (water jet punch apparatus) is shown in FIG. FIG. 2 is a schematic view of the nozzle plate and holes used.

  The ultra-fine short fiber nonwoven fabric thus obtained was a dense sheet in which PVA was completely dropped and the ultra-fine fibers were intertwined. The results of evaluating the physical properties are shown in Table 1.

Example 2
The surface of the ultra-thin short fiber nonwoven fabric obtained in Example 1 is a wide belt sander manufactured by Kikukawa Iron Works Co., Ltd., and the weight loss due to buffing of the fiber sheet is 5% by weight using a silicon carbide abrasive sandpaper having a particle size of P400. After buffing until it becomes, it dye | stained with the disperse dye in the circular dyeing machine. The results of evaluating the physical properties of the obtained leather-like sheet are shown in Table 1.

Example 3
Removal of PVA with a water jet punch consisting of a nozzle head with a 0.1 mm hole diameter and a 0.5 mm interval at a processing speed of 2 m / min, 10 MPa, 20 MPa, 25 MPa, 35 MPa on both sides (total 8 times) Except that the entanglement was performed, the same treatment as in Example 2 was performed to obtain an ultrafine short fiber nonwoven fabric. The ultra-short fiber nonwoven fabric thus obtained was a dense sheet in which ultra-fine fibers were intertwined. The results of evaluating the physical properties are shown in Table 1.

Example 4
An ultra-fine short fiber nonwoven fabric was obtained in the same manner as in Example 2 except that nylon 6 was used instead of polyethylene terephthalate as the island component. The ultra-short fiber nonwoven fabric thus obtained was a dense sheet in which ultra-fine fibers were intertwined. The results of evaluating the physical properties are shown in Table 1.

Example 5
With a water jet punch consisting of a nozzle head with a 0.1 mm hole diameter and an interval of 0.5 mm, the front and back surfaces are processed at 5 MPa and 16 MPa (total 4 times) at a processing speed of 1 m / min (total 4 times). Except having performed, it processed like Example 2 and obtained the ultra-fine short fiber nonwoven fabric. The ultra-short fiber nonwoven fabric thus obtained was a dense sheet in which ultra-fine fibers were intertwined. The results of evaluating the physical properties are shown in Table 1.

Example 6
Water jet punch with 0.1 mm hole diameter and 0.5 mm interval nozzle head, 3 MPa, water jet punch with 0.1 mm hole diameter, 0.2 mm interval nozzle jet, 16 MPa, 0.5 m The treatment was carried out in the same manner as in Example 2 except that both the front and back surfaces were treated at a treatment speed of 4 minutes per minute (total 4 times), and entanglement was performed together with the removal of PVA, to obtain an ultrafine short fiber nonwoven fabric. The ultra-short fiber nonwoven fabric thus obtained was a dense sheet in which ultra-fine fibers were intertwined. The results of evaluating the physical properties are shown in Table 1.

Example 7
With a 0.1mm hole diameter, water jet punch consisting of nozzle heads with a spacing of 0.2mm at 10MPa, treating both front and back twice at a treatment speed of 0.5m / min (total 4 times), with removal of PVA Except that the entanglement was performed, the same treatment as in Example 2 was performed to obtain an ultrafine short fiber nonwoven fabric. The ultra-short fiber nonwoven fabric thus obtained was a dense sheet in which ultra-fine fibers were intertwined. The results of evaluating the physical properties are shown in Table 1.

Example 8
An ultra-fine short fiber nonwoven fabric was obtained in the same manner as in Example 2 except that a sea-island composite fiber having a fiber length of 38 mm was used. The ultra-short fiber nonwoven fabric thus obtained was a dense sheet in which ultra-fine fibers were intertwined. The results of evaluating the physical properties are shown in Table 1.

Example 9
Except that the table was processed only once at a processing speed of 1 m / min at 20 MPa with a water jet punch consisting of a nozzle head with a 0.1 mm hole diameter and a 0.2 mm interval, and entangled with PVA removal. The same treatment as in Example 2 was performed to obtain an ultrafine short fiber nonwoven fabric. The ultra-short fiber nonwoven fabric thus obtained was a dense sheet in which ultra-fine fibers were intertwined. The results of evaluating the physical properties are shown in Table 1.

Example 10
With a 0.12 mm hole diameter, water jet punch consisting of nozzle heads with a spacing of 0.6 mm at 15 MPa, treating both front and back twice at a treatment speed of 5.0 m / min (4 times in total), with removal of PVA An ultrafine short fiber nonwoven fabric was obtained by the same treatment as in Example 2 except that the entanglement was performed. The ultra-short fiber nonwoven fabric thus obtained was a dense sheet in which ultra-fine fibers were intertwined. The results of evaluating the physical properties are shown in Table 1.

Example 11
With a water jet punch consisting of a nozzle head with a 0.14 mm hole diameter and a 0.6 mm interval, it is treated twice at a treatment speed of 5.0 m / min. An ultrafine short fiber nonwoven fabric was obtained by the same treatment as in Example 2 except that the entanglement was performed. The ultra-short fiber nonwoven fabric thus obtained was a dense sheet in which ultra-fine fibers were intertwined. The results of evaluating the physical properties are shown in Table 1.

Example 12
With a 0.20 mm hole diameter, water jet punch consisting of nozzle heads with 1.0 mm spacing at 35 MPa, treating both front and back twice at a treatment speed of 5.0 m / min (4 times in total), with removal of PVA An ultrafine short fiber nonwoven fabric was obtained by the same treatment as in Example 2 except that the entanglement was performed. The ultra-short fiber nonwoven fabric thus obtained was a dense sheet in which ultra-fine fibers were intertwined. The results of evaluating the physical properties are shown in Table 1.

Comparative Example 1
A front surface and a back surface were processed twice each at a processing speed of 0.5 m / min at 20 MPa with a water jet punch composed of a nozzle head having a diameter of 0.1 mm and an interval of 0.2 mm, and entangled with PVA removal. Was processed in the same manner as in Example 1 to obtain an ultrafine short fiber nonwoven fabric. The ultrafine short fiber nonwoven fabric obtained in this way had many holes with a diameter of about 0.5 to 5 mm, and was inferior in appearance. The results of evaluating the physical properties are shown in Table 1.

Comparative Example 2
A web was prepared through a card and a cross wrapper using a sea-island type composite fiber having a single fiber fineness of 3 dtex, 36 islands, and a fiber length of 51 mm consisting of 50 parts of polystyrene as a sea component and 50 parts of polyethylene terephthalate as an island component. Subsequently, it processed with the implantation density of 2500 pieces / cm < ² > with the 1 barb type needle punch, and obtained the composite short fiber nonwoven fabric of the fiber apparent density 0.210g / cm < ³ >. Next, it is immersed in an aqueous solution of polyvinyl alcohol 12% having a degree of polymerization of 500 and a degree of saponification of 88% heated to about 95 ° C. so as to have an adhesion amount of 25% with respect to the nonwoven fabric weight in terms of solid content, and impregnated with PVA. At the same time, shrinkage treatment was performed for 2 minutes, and dried at 100 ° C. to remove moisture. The obtained sheet was treated with trichrene at about 30 ° C. until the polystyrene was completely removed to obtain ultrafine fibers having a single fiber fineness of about 0.042 dtex. Next, treatment was performed at 10 MPa and 20 MPa on both surfaces at a processing speed of 1 m / min with a water jet punch composed of a nozzle head having a hole diameter of 0.1 mm and an interval of 0.6 mm, and entangled.

    The ultra-fine short fiber nonwoven fabric obtained in this way was inferior in form retention. The results of evaluating the physical properties are shown in Table 1.

Comparative Example 3
As the polymer diol, a 50:50 mixture of 2000 molecular weight polyhexamethylene carbonate diol and 2000 molecular weight polytrimethylene glycol, 4,4′-diphenylmethanediamine isocyanate as the diisocyanate, ethylene glycol as the chain extender, Polyurethane was obtained by the method and diluted with DMF so that the solid content was 12% by weight. Further, 1.5% by weight of a benzophenone-based ultraviolet absorber was added as an additive to prepare a polyurethane impregnating solution. Subsequently, the ultra-short fiber nonwoven fabric obtained in the same manner as in Comparative Example 1 was immersed in this polyurethane impregnating solution, and the amount of the impregnating solution was adjusted with a squeeze roll so that the solid content of the polyurethane was 60% of the fiber weight. After that, the polyurethane was coagulated in an aqueous DMF solution. Thereafter, DMF was removed with hot water at 85 ° C. and then dried at 100 ° C. The surface of this sheet was buffed with a wide belt sander manufactured by Kikukawa Iron Works Co., Ltd. using a silicon carbide abrasive sandpaper with a particle size of P400 until the weight loss due to buffing of the fiber sheet was 5% by weight. It was dyed with disperse dyes in a dyeing machine. The physical properties of the obtained leather-like sheet were good as shown in Table 1. However, it has a hard and rubber-like texture, no solidity similar to that of natural leather, and a leather-like sheet having a sufficient texture cannot be obtained.

Side surface schematic of the high-speed fluid processing apparatus used in Examples 1-9 and Comparative Examples 1-3. The figure of an example of a nozzle plate.

Explanation of symbols

1: Nonwoven fabric 2: Net conveyor 3: Chamber 4: High-speed fluid 5: Nozzle plate 6: Hole 7: Hole diameter 8: Hole interval

  According to the present invention, it is possible to obtain sufficient physical properties and quality as a leather-like sheet-like material even if it is a nonwoven fabric structure that is substantially free of a polymer elastic body and mainly made of a fiber material. The ultra-fine short fiber nonwoven fabric of the present invention has excellent recyclability, easy care properties, yellowing resistance, etc., so it can be used for clothing, furniture, car seats, miscellaneous goods, abrasive cloths, wipers, filters, etc. Of these, it can be preferably used especially for car seats and clothing by taking advantage of the recyclability and characteristic texture. In addition, the ultra-fine short fiber nonwoven fabric of the present invention is a napped leather-like sheet-like material, and the ultra-fine fibers are less likely to be bundled and have excellent surface fiber denseness, spreadability, and uniformity. It is also useful and preferable as a polishing cloth for polishing a material.

Claims (12)

Including ultra-fine short fibers with a single fiber fineness of 0.0001 to 0.5 dtex, a basis weight of 100 to 550 g / m ² , a tensile strength of 70 N / cm or more, a tear strength of 3 to 50 N, and wear resistance of 3 to 5 grades An ultra-fine short fiber nonwoven fabric characterized by consisting essentially of a non-elastic polymer fiber material. A leather-like sheet obtained by dyeing the ultrafine short fiber nonwoven fabric according to claim 1. Including ultra-fine short fibers with a single fiber fineness of 0.0001 to 0.5 dtex, a basis weight of 100 to 550 g / m ² , a tensile strength of 70 N / cm or more, a tear strength of 3 to 50 N, and an abrasion resistance of grades 3 to 5 A leather-like sheet-like material characterized by consisting essentially of a dyed fiber material of an inelastic polymer. High-speed fluid treatment at a flow rate of 160 to 800 L / m ² at least once on a web and / or nonwoven fabric having a basis weight of 100 to 550 g / m ² and containing ultrafine short fibers having a single fiber fineness of 0.0001 to 0.5 dtex The manufacturing method of the ultra-fine short fiber nonwoven fabric characterized by performing these. Single fiber fineness containing ultrafine short fibers of 0.0001～0.5Dtex, basis weight of the web and / or nonwoven 100~550g / ^{m 2,} is subjected to high speed fluid treatment at a total flow rate of 550~2000L / ^{m 2} A method for producing an ultrafine short fiber nonwoven fabric characterized by the following. Furthermore, the high-speed fluid treatment is performed at a flow rate of 160 to 800 L / m ^2. The method for producing an ultrafine short fiber nonwoven fabric according to claim 5. The method for producing an ultrafine short fiber nonwoven fabric according to any one of claims 4 to 6, wherein high-speed fluid treatment is performed using a nozzle having a diameter of 0.06 to 0.15 mm. Arranged on a web and / or non-woven fabric containing ultrafine short fibers having a single fiber fineness of 0.0001 to 0.5 dtex and having a basis weight of 100 to 550 g / m ^{2 with} a pore spacing of 0.15 to 2.50 mm at least once. A method for producing an ultra-fine short fiber nonwoven fabric, wherein high-speed fluid treatment is performed with a jet force of 0.16 to 1.60 N per hole from the nozzle formed. The method for producing an ultrafine short fiber nonwoven fabric according to any one of claims 4 to 8, wherein an aspect ratio of the ultrafine short fibers is 5,000 to 900,000. A composite short fiber nonwoven fabric is produced by a needle punch method using a composite short fiber of 1 to 50 dtex, and then a web or a nonwoven fabric containing the ultrafine short fiber obtained by performing an ultrafine fiber expression treatment is used. The manufacturing method of the ultra-fine short fiber nonwoven fabric of any one of 4-9. The method for producing an ultrafine short fiber nonwoven fabric according to any one of claims 4 to 10, wherein a web or a nonwoven fabric containing 3 to 60% by weight of a water-soluble form stabilizer is used. The method for producing an ultrafine short fiber nonwoven fabric according to any one of claims 10 and 11, wherein the composite short fibers are sea-island type composite short fibers.

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