JP2013024404A - Back plate for disk brake pad, disk brake pad using the same, and method of manufacturing back plate and disk brake pad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a back plate for a disk brake pad which uses resin having practically improved characteristics such as strength, ductility, heat resistance, or the like, and to provide a disk brake pad using the back plate and a method of manufacturing the back plate and the disk brake pad.SOLUTION: This back plate for a disk brake pad is manufactured of an inorganic fiber-reinforced plastic obtained by stacking prepregs which are manufactured by impregnating inorganic fibers of woven cloth or nonwoven cloth with a thermosetting resin composition. The thermosetting resin composition impregnation ratio of the inorganic fiber-reinforced plastic is 30-70 mass%. The disk brake pad uses the back plate. The method of manufacturing the back plate and the disk brake pad includes a prepreg preparation step and a prepreg stacking step. The viscosity of the thermosetting resin composition to be used in the prepreg preparation step is 0.3-5.0 Pas at 150°C.

Description

  The present invention relates to a back plate for a disc brake pad used for braking a two-wheeled vehicle or a four-wheeled vehicle, a disc brake pad using the same, and a manufacturing method thereof.

  Usually, a brake disc brake pad attached to a two-wheeled vehicle or a four-wheeled vehicle is composed of a back plate and a friction material. Surface processing after the metal back plate surface is laminated by heat pressure sintering with a friction material layer pre-compounded with phenol resin, organic / inorganic fibers, metal and ceramics components, and then compacted. It is manufactured by giving.

  In recent years, with the progress of environmentally friendly and fuel-efficient automobiles, lightening of parts of automobiles has been studied and implemented. Normally, metal materials account for more than half of the composition of raw materials, but their usage is decreasing year by year due to the weight reduction of the vehicle body. In order to further reduce the weight, materials that have been increasing in recent years are aluminum and resin. Since the specific gravity of the steel sheet is about 7.8, and the specific gravity of aluminum is about 2.7 and the specific gravity of the resin is about 1, the weight can be reduced to 50% or less.

  A back plate using the above resin has been reported to be compression-molded with a phenol resin containing glass fibers of about 0.1 to 10 mm (see, for example, Patent Documents 1 and 2). However, many properties such as strength, toughness, and heat resistance are lower than those of steel backplates.

JP 2001-165210 A JP 2001-253998 A

  The present invention has been made in view of the above-mentioned background art, and a back plate using a resin whose many properties such as strength, toughness and heat resistance are improved to a practical level, a disc brake pad using the same, and a method of manufacturing the same The purpose is to provide.

The present invention is a back plate made of an inorganic fiber reinforced plastic in which a prepreg impregnated with a thermosetting resin is impregnated with inorganic fibers which are woven or non-woven fabric, and the resin impregnation rate of the inorganic fiber reinforced plastic is 30. Relates to a back plate which is ˜70% by weight.
Moreover, this invention relates to the said backplate whose said inorganic fiber is glass fiber.
The present invention also relates to the back plate as described above, wherein the bending strength in the direction perpendicular to the laminated surface of the inorganic fiber reinforced plastic is 150 to 500 MPa.
The present invention also relates to a disc brake pad including the back plate and the friction material described above.
Further, the present invention is a method for producing a backplate, comprising a prepreg creation step of making a prepreg by impregnating a thermosetting resin into an inorganic fiber, and a lamination step of laminating the prepreg, wherein the heat used in the prepreg creation step The present invention relates to a method for producing a back plate in which the viscosity of the curable resin is 0.3 to 5.0 Pa · s at 150 ° C.
The present invention also relates to the method for manufacturing the back plate as described above, further comprising a step of providing a friction material on the back plate.

  According to the back plate of the present invention, many characteristics such as strength, toughness, and heat resistance of a back plate using a resin can be improved to a practical level. In addition, since the inorganic fiber reinforced prepreg has an overwhelmingly lower specific gravity than that of metal, the weight of the vehicle body can be reduced, and an effect of reducing fuel consumption can be expected.

It is a schematic diagram which shows the test method of the bending strength of a horizontal direction with respect to the lamination surface of the inorganic fiber reinforced plastic in this invention.

  One form of the back plate of the present invention is formed by laminating a prepreg in which a thermosetting resin is impregnated with inorganic fibers which are woven or non-woven fabrics. One embodiment of the disc brake pad of the present invention comprises at least a friction material layer and an inorganic fiber reinforced prepreg. Hereinafter, each structure is demonstrated in order. Although one embodiment of the present invention will be described in detail with reference to the drawings, the present invention is not limited to the following embodiment, and can be arbitrarily changed without departing from the gist of the present invention. .

  The back plate in the present invention has an inorganic fiber reinforced plastic in which a prepreg obtained by impregnating inorganic fibers with a thermosetting resin is laminated.

  The thickness of the back plate in the present invention can be adjusted by the number of prepregs to be laminated. This thickness depends on the design of the disc brake, but is preferably 5.0 to 7.0 mm, more preferably 5.5 to 6.5 mm. If the thickness is smaller than this, the strength of the back plate cannot be maintained, and the occurrence of squeal is also a problem. On the other hand, if the thickness is larger than this, the friction material has to be thinned, resulting in a problem in durability.

  Examples of the inorganic fibers in the present invention include woven fabrics and nonwoven fabrics such as glass fibers and carbon fibers. This gives a fiber reinforced plastic with excellent strength. Among these, a glass fiber woven fabric is preferable from the viewpoint of surface treatment with a coupling agent and resin impregnation, and a carbon fiber woven fabric is preferable from the viewpoint of strength.

  The thermosetting resin in the present invention is not particularly limited, but is preferably a phenol resin and its curing agent or an epoxy resin and its curing agent from the viewpoint of strength. In order to impart heat resistance, strength, and toughness against heat generation during braking, it is preferable that an epoxy resin and its curing agent, or a phenol resin and its curing agent are the main components.

  The epoxy resin used in the present invention is preferably an epoxy resin having an aromatic ring from the viewpoint of strength and heat resistance. Specifically, a novolac epoxy resin such as a phenol novolac epoxy resin or a cresol novolac epoxy resin, a naphthalene epoxy resin, or the like can be preferably used.

  The said epoxy resin can use the commercial item which is easy to obtain, can also synthesize | combine by a conventional method, and can use them combining 1 type (s) or 2 or more types. The epoxy resin that can be used in the present invention is not particularly limited. For example, phenol, cresol, xylenol, resorcin, catechol, bisphenol A, bisphenol including phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, and the like. F and other phenols and / or naphthols such as α-naphthol, β-naphthol and dihydroxynaphthalene and a compound having an aldehyde group such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and salicylaldehyde are condensed or co-polymerized in an acidic catalyst. Epoxidized novolak resin obtained by condensation, diglycidyl ether such as bisphenol A, bisphenol F, bisphenol S, bisphenol A / D, al Biphenyl type epoxy resin which is diglycidyl ether of killed or unsubstituted biphenol, phenol aralkyl resin or naphthol aralkyl resin synthesized from phenol and / or naphthol and dimethoxyparaxylene or bis (methoxymethyl) biphenyl Epoxidized products such as biphenyl / aralkyl resins, stilbene type epoxy resins, hydroquinone type epoxy resins, glycidyl ester type epoxy resins obtained by reaction of polybasic acids such as phthalic acid and dimer acid with epichlorohydrin, diaminodiphenylmethane, isocyanuric acid, etc. Dicyclope, a glycidylamine-type epoxy resin obtained by the reaction of polyamines with epichlorohydrin, and an epoxidized product of a co-condensation resin of cyclopentadiene and phenols Tadiene type epoxy resin, epoxy resin having naphthalene ring, triphenylmethane type epoxy resin, trimethylolpropane type epoxy resin, terpene modified epoxy resin, epoxy resin containing sulfur atom, olefin bond is oxidized with peracid such as peracetic acid. Examples thereof include linear aliphatic epoxy resins, alicyclic epoxy resins, and epoxy resins obtained by modifying these epoxy resins with silicone, acrylonitrile, butadiene, isoprene rubber, polyamide resin, or the like.

  The curing agent for the epoxy resin is not particularly limited, but a phenolic curing agent is preferably used from the viewpoint of heat resistance and strength after curing, and an easily available commercial product can be used. It can also synthesize | combine by a conventional method and can be used combining those 1 type (s) or 2 or more types. Although not particularly limited, examples of phenolic curing agents that can be used in the present invention include phenols such as phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol, aminophenol, and / or α. -Novolac type phenol resins obtained by condensation or cocondensation of naphthols such as naphthol, β-naphthol, dihydroxynaphthalene and the like and compounds having an aldehyde group such as formaldehyde, benzaldehyde and salicylaldehyde under an acidic catalyst, phenols and / or Or aralkyl such as phenol aralkyl resin, naphthol aralkyl resin, biphenyl aralkyl resin synthesized from naphthols and dimethoxyparaxylene or bis (methoxymethyl) biphenyl Type phenol resin, dicyclopentadiene type phenol resin, terpene-modified phenol resin, and triphenylmethane type phenol resin. These resins may be used alone or in combination of two or more.

  Examples of the phenol resin used in the present invention include a solid novolac type phenol resin and a solid resol type phenol resin, and are not particularly limited.

  The said phenol resin can use a novolak type or a resol type, combining those 1 type (s) or 2 or more types. The novolak type phenol resin used in the present invention is not particularly limited, and examples thereof include a random novolak resin and a high ortho novolak resin. The novolak type phenolic resin is obtained by combining phenols and formaldehyde with Group 2 elements or transition elements and organic monocarboxylic acids such as formic acid and acetic acid or inorganic acids such as boric acid, hydrochloric acid and nitric acid in the presence of an acid catalyst such as oxalic acid. It can be synthesized by reacting in the presence of a salt. The resol type phenol resin used in the present invention is not particularly limited, and examples thereof include a methylol type and a dimethylene ether type. Among these, the dimethylene ether type is preferable because of a good balance between curability and thermal stability. Is preferably used. The dimethylene ether type resole resin is a compound of phenol and formaldehyde in the presence of a salt of a group 2 element or transition element of the periodic table and an organic monocarboxylic acid such as formic acid or acetic acid or an inorganic acid such as boric acid, hydrochloric acid or nitric acid. It can be synthesized by reacting.

  The resin impregnation rate of the inorganic fiber reinforced prepreg in the present invention is 30 to 70% by mass. Thereby, it is excellent in the ease of processing of prepreg lamination molding. Furthermore, it is preferable that it is 40-65 mass% from a viewpoint of bending strength, and it is more preferable that it is 50-60 mass%.

The impregnation rate in the present invention is calculated as in the following formula (1).

Resin composition impregnation rate (mass%) = [mass of resin composition / {(mass of woven fabric or nonwoven fabric, or both) + mass of resin composition}] × 100 (1)

  Since the resin is solid at room temperature or lowers the viscosity of the resin, a solvent, particularly an organic solvent may be used. By using a solvent, the impregnation property can be improved with respect to the woven fabric and the nonwoven fabric. Of course, when the resin is liquid at room temperature, a solvent may be used for the purpose of adjusting the viscosity.

  The solvent is not particularly limited, but ketones such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK) and cyclohexanone (CHN), aromatic hydrocarbons such as xylene, aliphatic hydrocarbons such as heptane, propylene Examples thereof include alcohols such as glycol monomethyl ether, propylene glycol monomethyl ether acetate, 3-methoxy-3-methyl-1-butanol, 2- (2-methoxyethoxy) ethanol, and 2-butanol.

  Among these solvents, from the viewpoint of solubility, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone (CHN) can be exemplified as preferable examples. However, the present invention is not limited thereto, and a solvent that can dissolve or disperse the resin. If present, a wide range of organic solvents can be used.

  Furthermore, a normal inorganic filler and an organic filler can be mix | blended with the backplate of this invention as a filler. These may be used alone or in admixture of two or more.

  The inorganic filler is not particularly limited as long as it is a solid particulate inorganic compound. Specific examples of the material of the inorganic filler include, for example, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina, aluminum nitride, aluminum borate whisker, Examples include boron nitride, crystalline silica, amorphous silica, and antimony oxide. An inorganic filler is used individually by 1 type or in combination of 2 or more types.

  In order to improve thermal conductivity, the material of the inorganic filler is preferably metal powder or metal fiber, or ceramic such as alumina, aluminum nitride, boron nitride, crystalline silica, or amorphous silica. For the purpose of adjusting the melt viscosity and imparting thixotropic properties, the inorganic filler is aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina, Crystalline silica or amorphous silica is preferred.

  The content of the filler is preferably 3 to 30 parts by mass from 100 parts by mass of the thermosetting resin component from the viewpoint of heat resistance after molding and curing, and the viewpoint of the viscosity of the thermosetting resin at 150 ° C. Is more preferably 5 to 15 parts by mass. When this content ratio is less than 3 parts by mass, when the fiber-reinforced prepreg is hot-pressure laminated, the resin before curing flows out, the resin content in the laminate is lowered, and the strength tends to be lowered. On the other hand, when this content ratio exceeds 30 mass parts, the impregnation property to a woven fabric and a nonwoven fabric will fall, and the adhesiveness of an interface will fall at the time of lamination | stacking. When this content ratio is in the above numerical range, the fluidity of the resin is controlled during the hot-pressure lamination, the resin is held in the laminated plate, and the effect of improving the adhesion at the interface tends to be obtained.

  The viscosity of the thermosetting resin before curing (that is, a prepreg creation step of creating a prepreg by impregnating an organic fiber with a thermosetting resin) is preferably 0.3 to 5.0 Pa · s, 0.5 More preferably, it is -2.5 Pa.s. When the viscosity of the thermosetting resin before curing is less than 0.3 Pa · s, when the fiber reinforced prepreg is hot-pressure laminated, the resin before curing flows out, the resin content in the laminate is reduced, and the strength is reduced. There is a tendency to decrease. On the other hand, when the viscosity of the thermosetting resin before curing exceeds 5.0 Pa · s, the impregnation property of the woven fabric / nonwoven fabric tends to decrease, and the adhesion at the interface tends to decrease during lamination. Since the viscosity before curing of the thermosetting resin is within the above numerical range, the fluidity of the resin is controlled at the time of hot-pressure lamination, the resin is held in the laminated plate, and the adhesion at the interface is improved. can get.

  The viscosity in the present invention is the force F generated between the liquid and the plate when the two flat plates of area A sandwiching the liquid of thickness h move at a relative speed U is F = μAU / h. It is defined and is this proportionality constant μ. Examples of the method for measuring the viscosity include the following methods. Heat before curing between the upper conical surface and the lower flat plate of rotational viscometer (Research Equipment (London), trade name: ICI CONE & PLATE VISCOMETER) with a very obtuse conical surface and flat plate The lower flat plate is heated to 150 ° C. by sandwiching the curable resin, the upper conical surface is rotated, and the viscosity after 10 seconds is measured.

  Although the manufacturing method of the inorganic fiber reinforced plastic in the present invention is not particularly limited, it can be obtained by impregnating the inorganic fiber with a thermosetting resin, heating and molding. The method for impregnating the inorganic fiber with the thermosetting resin is not particularly limited. For example, the thermosetting resin is dissolved in the solvent, and the inorganic fiber woven fabric or the nonwoven fabric is immersed in the solution. A prepreg can be prepared by drying this at 80 ° C. for 30 minutes.

  An example of the manufacturing method of the inorganic fiber reinforced prepreg using glass fiber is shown below. Apply a suitable amount of matrix resin to a unidirectional prepreg of glass fiber, or a knitted fabric (how to knitting is not limited) or a glass nonwoven fabric that is manufactured as necessary to improve thermal conductivity, strength, etc. It is preferable to obtain it by laminating to a thickness, heating and molding. Further, it is also preferable to perform (pressurization) molding at a pressure of 10 MPa or less with an autoclave, a pressure molding machine, or the like depending on the thickness, glass fiber content, and the like.

  The inorganic fibers contained in the inorganic fiber reinforced prepreg are preferably oriented substantially in the horizontal direction with respect to the laminated surface in the inorganic fiber reinforced plastic, and more preferably partially oriented in the vertical direction. That is, in the inside of the inorganic fiber reinforced prepreg, the inorganic fiber is oriented in the horizontal direction with respect to the plane direction of the inorganic fiber reinforced prepreg, that is, the laminated surface with the back plate or the friction material layer. The heat transmitted to the prepreg is preferably transmitted in the horizontal direction with respect to the laminated surface and easily radiated to the outside. Further, it is more preferable to include partially oriented inorganic fibers because the weakness of the interface between the inorganic fiber prepregs can be reinforced.

  The bending strength of the inorganic fiber reinforced plastic in the horizontal direction with respect to the laminated surface is not particularly limited, but is preferably 150 to 500 MPa, more preferably 200 to 500 MPa. In order to make the bending strength in the above range, for example, the content of the resin in the inorganic fiber reinforced plastic is made in the above range, or the thermosetting resin contains a filler. By setting the bending strength in the horizontal direction with respect to the laminated surface within the above range, the brake pad can be uniformly frictionally engaged with the brake rotor without bending the brake pad during braking.

  As shown in FIG. 1, the “bending strength in the horizontal direction with respect to the laminated surface” in the present invention is such that both ends of the inorganic fiber reinforced plastic 1 are supported by fulcrums 2 and a pressure wedge 3 is provided at the center of the inorganic fiber reinforced plastic. The bending strength measured by applying a force in the direction perpendicular to the laminate surface, that is, the bending strength measured by a three-point bending test (according to JIS K 6911). Specifically, it is measured by the method described in the examples.

  The thickness of the inorganic fiber reinforced prepreg is not particularly limited, but is preferably 0.2 to 7 mm, particularly preferably 0.5 to 5 mm in consideration of vertical and horizontal heat dissipation effects, brake caliper size, mass, and the like. .

  The inorganic fiber reinforced prepreg may contain “fiber other than glass fiber” such as carbon fiber, Kevlar fiber, and natural fiber, if necessary. These “fibers other than glass fibers” have an effect as a reinforcing material.

Examples of the present invention will be specifically described below in comparison with comparative examples. However, the present invention is not limited to these examples as long as the structural requirements are satisfied.

(Examples 1-6 and Comparative Examples 1-4)
An epoxy resin, a phenol resin, and a catalyst (curing agent) having trade names and blending ratios (mass ratios) shown in Tables 1 and 2 were dissolved and dispersed in methyl ethyl ketone, respectively. A filler was also added to these at the compounding ratios shown in Tables 1 and 2, and each component was stirred until it became uniform to obtain a varnish.

  Next, each woven fabric or nonwoven fabric was impregnated with the varnish according to Tables 1 and 2. This varnish-containing fiber cloth was dried by heating at 25 ° C. for 1 hour and at 80 ° C. for 1 hour. A fiber-reinforced prepreg was thus obtained. However, Example 5 was further dried at 80 ° C. for 1 hour.

Below, the detail of each component is shown.
1032H60 (trade name): manufactured by Mitsubishi Chemical Corporation, triphenylglycidylmethane type epoxy resin, epoxy equivalent: 170 g / eq
EXA4710 (trade name): manufactured by DIC Corporation, naphthalene type tetrafunctional epoxy resin, epoxy equivalent: 167 g / eq
HE910-10 (trade name): manufactured by Air Water Co., Ltd., phenol resin, hydroxyl group equivalent: 103 g / eq
R972: Aerosil R972 (trade name), manufactured by Nippon Aerosil Co., Ltd., silica filler, average particle size: 0.016 μm
2PZ-CN: Curesol 2PZ-CN (trade name), manufactured by Shikoku Chemicals Co., Ltd., 1-cyanoethyl-2-phenylimidazole

  The above fiber reinforced prepreg was cut into 90 mm × 90 mm, and after laminating 7 sheets, the film was heated and pressed at 150 ° C. for 2 minutes under a pressure of 2 MPa under vacuum, and then heated and pressed at 180 ° C. for 10 minutes. The body was heat-cured at 240 ° C. for 1 hour in a heating furnace to obtain an inorganic fiber reinforced plastic laminate.

The resin composition impregnation rate was calculated by the above formula (1).
For example, calculating Example 1
Resin composition impregnation ratio (mass%) = (100 + 165 + 3 + 13.3) / (100 + 165 + 3 + 13.3 + 546.1) × 100 = 34.0 (mass%).

(Evaluation)
Using the laminates obtained in Examples 1 to 6 and Comparative Examples 1 to 4, the following items were evaluated.

[Bending strength]
The laminates of Examples 1 to 6 and Comparative Examples 1 to 4 were subjected to the method described in JIS K 6911 (sample size: width 5 mm) using a material testing device manufactured by INSTRON Co., Ltd., trade name: 5548 Micro Tester. X thickness 1 mm, distance between supporting points: 20 mm, crosshead speed: 2 mm / min), the bending strength in the horizontal direction with respect to the laminated surface at 25 ° C. was measured. The results are summarized in Tables 1 and 2.

  As described above, the present invention uses a glass fiber reinforced prepreg laminate for the disc brake back plate, so that the brake can be made lighter and can contribute to the improvement of the fuel consumption of the automobile.

  Further, since the back plate is lighter, the damping rate of the vibration is increased and the squealing of the brake can be prevented. Further, since the back plate does not rust, the need for painting is eliminated. Since the fibers to be mixed are short fibers, the fibers can be evenly distributed in the back plate, and the homogeneity of the back plate can be ensured.

1 Fiber reinforced plastic 2 Support point 3 Pressure wedge L Distance between support points

Claims (6)

  A back plate for a disc brake pad made of an inorganic fiber reinforced plastic in which a prepreg impregnated with a thermosetting resin composition is impregnated with a woven or non-woven inorganic fiber, the thermosetting property of the inorganic fiber reinforced plastic A back plate for a disc brake pad having a resin composition impregnation rate of 30 to 70% by mass.   The disc brake pad back plate according to claim 1, wherein the inorganic fibers are glass fibers.   The back plate for a disc brake pad according to claim 1 or 2, wherein the bending strength in the direction perpendicular to the laminated surface of the inorganic fiber reinforced plastic is 150 to 500 MPa.   A disc brake pad comprising the back plate for a disc brake pad according to claim 1 and a friction material.   A method for producing a disc brake pad backplate, comprising: a prepreg creating step of impregnating a thermosetting resin composition into an inorganic fiber to create a prepreg; and a laminating step of laminating the prepreg, which is used in the prepreg creating step A method for producing a back plate for a disc brake pad, wherein the viscosity of the thermosetting resin composition is 0.3 to 5.0 Pa · s at 150 ° C.   A method for manufacturing a disc brake pad, comprising a step of further providing a friction material on the back plate for the disc brake pad manufactured by the manufacturing method according to claim 5.

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