JP2008164167A - Transmission belt and method of manufacturing transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission belt and a method of manufacturing the transmission belt excelling in machinability, adhesive property, wear resistance and durability. <P>SOLUTION: A toothed belt 1 has a plurality of tooth parts 2 along the longitudinal direction of the belt, and a belt body composed of a back part 4 with core wires 3 embedded. Tooth cloth 5 is stuck to the surface of the tooth parts 2 if necessary. The tooth part 2 is composed of a crosslinked substance of a rubber composition prepared by mixing 1-50 pts.mass of unsaturated calboxylate ester containing active hydrogen into 100 pts.mass of a rubber component containing hydrogenated nitrile rubber. Specific examples of unsaturated calboxylate ester can be methacrylate ester and/or acrylic acid ester containing a hydroxyl group and/or a carboxyl group. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power transmission belt used for power transmission such as a driving device and a method for manufacturing the power transmission belt.

  In recent years, the quality required for transmission belts has become stricter year by year. In particular, power transmission belts used in automobile engines must be able to withstand the temperature in the engine room, which was originally harsh as the environmental temperature, but the temperature in the engine room tends to rise further. The transmission belt is also required to withstand extremely high temperatures. In addition, as the space is saved and the engine is made more compact, the engine room has become considerably narrower, and there is a demand for a narrower belt.

In response to the demand for improvement in heat resistance, it has been proposed to use a hydrogenated nitrile rubber crosslinked with an organic peroxide as a rubber composition constituting the tooth rubber and back rubber of a toothed belt. (For example, refer to Patent Document 1) And for the demand for narrowing, the rubber properties are improved by increasing the amount of reinforcing material such as carbon black silica, organic peroxide, vulcanization accelerator, and co-crosslinking agent. Studies are underway to deal with the narrowing.
Japanese Patent Application Laid-Open No. 64-87937

  However, when a rubber composition filled with carbon black is used for a transmission belt that repeatedly receives compressive force, processability deteriorates and large aggregates of carbon black are generated, resulting in reinforcement, wear resistance, and tensile strength. Strength and hysteresis were not exhibited, and bending fatigue was inferior, causing an early belt life. In addition, since it is inferior in adhesion to the fiber cord serving as the core wire, there is a problem that the composite is not well formed and the belt life is shortened.

  The present invention addresses such problems and manufactures a power transmission belt and a power transmission belt that have improved workability and improved adhesion and wear resistance while maintaining excellent physical properties such as hardness and modulus. It aims to provide a method.

  That is, in the invention of claim 1 of the present application, a rubber whose transmission surface is blended with 1 to 50 parts by mass of an unsaturated carboxylic acid ester containing active hydrogen per 100 parts by weight of a rubber component containing hydrogenated nitrile rubber. A power transmission belt comprising a cross-linked product of the composition.

  The invention of claim 2 of the present application is the transmission belt according to claim 1, wherein the unsaturated carboxylic acid ester is a methacrylic acid ester and / or an acrylic acid ester.

  The invention of claim 3 of the present application is the transmission belt according to claim 1 or 2, wherein the cross-linked product is an organic peroxide-based cross-linked product.

  The invention according to claim 4 of the present application is the transmission belt according to any one of claims 1 to 3, wherein the rubber component is a composite comprising (i) a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt. It is characterized by blending a polymer body and (b) hydrogenated nitrile rubber.

  The invention according to claim 5 of the present application is the transmission belt according to claim 4, wherein the rubber component is (b) hydrogenated nitrile rubber and unsaturated carboxylic acid metal salt in a mass ratio of 30:70 to 70:30. The composite polymer body and (b) hydrogenated nitrile rubber are blended so as to have a mass ratio of 10:90 to 60:40.

  The invention according to claim 6 of the present application is the power transmission belt according to any one of claims 1 to 5, wherein silica is blended in the rubber composition.

  The invention of claim 7 of the present application is the transmission belt according to any one of claims 1 to 6, wherein the transmission belt is a toothed belt.

  In the invention of claim 8, the transmission surface of the transmission belt is composed of 1 to 50 parts by mass of unsaturated carboxylic acid ester containing active hydrogen, and 100 parts by mass of rubber component containing hydrogenated nitrile rubber. It is a method for producing a transmission belt, which is formed by crosslinking a rubber composition containing an agent.

  The invention of claim 9 of the present application is the method for producing a transmission belt according to claim 8, wherein the unsaturated carboxylic acid ester is a methacrylic acid ester and / or an acrylic acid ester.

  The invention of claim 10 of the present application is the method for producing a transmission belt according to claim 8 or 9, wherein the crosslinking agent is an organic peroxide.

  The invention of claim 11 of the present application is the method for producing a power transmission belt according to any one of claims 8 to 10, wherein the rubber component comprises (i) a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt. It is characterized by blending the blended composite polymer and (b) hydrogenated nitrile rubber.

  The invention of claim 12 of the present application is the method for producing a transmission belt according to claim 11, wherein the rubber component is (i) a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt in a mass ratio of 30:70 to 70: The composite polymer body blended at 30 and (b) hydrogenated nitrile rubber are blended so as to have a mass ratio of 10:90 to 60:40.

  A thirteenth aspect of the present invention is the method for producing a transmission belt according to any one of the eighth to twelfth aspects, wherein the rubber composition is blended with silica.

  The invention of claim 14 of the present application is the method for manufacturing a transmission belt according to any one of claims 8 to 13, wherein the transmission belt is a toothed belt.

  The power transmission belt of the present invention is composed of a specific rubber composition, so that it has high hardness, high wear resistance, high durability, and excellent adhesion, so that it is well compounded with other members. A transmission belt can be provided. Further, by selecting a specific unsaturated carboxylic acid ester, more excellent durability, wear resistance, and adhesive effect can be obtained. Moreover, the outstanding durable effect can be show | played because a crosslinked material is an organic peroxide type crosslinked material. Further, by making the rubber component a blend of a composite polymer and hydrogenated nitrile rubber, various physical properties such as tensile modulus, hardness, cutting elongation, and tear strength can be enhanced. Furthermore, by setting the blend ratio within a specific range, it is possible to ensure tensile modulus, cut elongation, higher tear strength, hardness, and the like. And it can be set as the power transmission belt provided with the more excellent adhesiveness and abrasion resistance by mix | blending a silica with a rubber composition. Moreover, by applying to a toothed belt, damage to the tooth portion can be suppressed, and the core wire and rubber can be combined well, and the life of the belt can be extended.

  In addition, the present invention forms a transmission surface by cross-linking a specific rubber composition, so that the workability is good, the hardness is high, the wear resistance is high, and the durability is high. Therefore, it is possible to manufacture a transmission belt that is well compounded with other members. Further, by selecting a specific unsaturated carboxylic acid ester, more excellent durability, wear resistance, and adhesive effect can be obtained. Moreover, the durable effect can be show | played because a crosslinking agent is an organic peroxide. Further, by making the rubber component a blend of a composite polymer and hydrogenated nitrile rubber, various physical properties such as tensile modulus, hardness, cutting elongation, and tear strength can be enhanced. Furthermore, by setting the blend ratio within a specific range, it is possible to ensure tensile modulus, cut elongation, higher tear strength, hardness, and the like. And it can be set as the power transmission belt provided with the more excellent adhesiveness and abrasion resistance by mix | blending a silica with a rubber composition. Further, by applying to a toothed belt, it is possible to provide a method for manufacturing a toothed belt that suppresses damage to the tooth portion and extends the life of the belt.

  The transmission belt of the present invention is a rubber composition in which the transmission surface is blended with 1 to 50 parts by mass of an unsaturated carboxylic acid ester containing active hydrogen with respect to 100 parts by mass of a rubber component containing hydrogenated nitrile rubber. It is composed of a crosslinked product.

  The hydrogenated nitrile rubber (H-NBR) used in the present invention has an acrylonitrile bond amount of 10 to 40% by mass composed of an unsaturated nitrile such as acrylonitrile or methacrylonitrile, and 1,3-butadiene or 2,3-dimethylbutadiene. , Copolymers of 90 to 60% by weight of conjugated dienes such as isoprene and 1,3-pentadiene, and multi-component copolymers obtained by copolymerizing a copolymerizable ethylenically unsaturated monomer in addition to these monomers Is mentioned. If the amount of the unsaturated nitrile in the nitrile rubber is too small, the hardness, modulus and oil resistance will be lowered and the function as a transmission belt will not be satisfied, and conversely if too much, the cold resistance will be lowered and the hardness and modulus will be reduced. However, there are problems such as inferior general physical properties.

  Examples of the ethylenically unsaturated monomer include vinyl aromatic compounds such as styrene, chloromethyl styrene, and α-methyl styrene, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, ethoxyethyl acrylate, maleic acid , Unsaturated dicarboxylic acids such as itaconic acid, monomethylmaleic acid ester and dimethylmaleic acid ester, and monoesters and diesters of these unsaturated dicarboxylic acids.

  H-NBR can be used alone, but for example, it is possible to use (B) a composite polymer containing H-NBR and an unsaturated carboxylic acid metal salt and (B) H-NBR. It is preferable for improving various physical properties such as tensile elastic modulus, hardness, elongation at break, and tear strength. By comprising in this way, it is thought that unsaturated carboxylic acid metal salt makes a polymer part high order structure, and it forms the filler which unsaturated carboxylic acid metal salt disperse | distributed finely by polymer part, and H-NBR whole quantity from the beginning It can have a higher tensile strength than blending an unsaturated carboxylic acid metal salt in the minute.

  More desirably, the rubber component comprises (a) a composite polymer obtained by blending H-NBR and an unsaturated carboxylic acid metal salt in a mass ratio of 30:70 to 70:30 and (b) H-NBR in a mass ratio of 10. : It is preferable to use a rubber component blended at 90 to 40:60 in order to ensure tensile modulus, elongation at break, higher tear strength, hardness and the like.

  The unsaturated carboxylic acid metal salt is an ionic bond of an unsaturated carboxylic acid having a carboxyl group and a metal. Examples of the unsaturated carboxylic acid include monocarboxylic acids such as acrylic acid and methacrylic acid, maleic acid, fumaric acid, Dicarboxylic acids such as itaconic acid are preferred, and the metals are beryllium, magnesium, calcium, strontium, barium, titanium, chromium, molybdenum, manganese, iron, cobalt, nickel, copper, silver, zinc, cadmium, aluminum, tin, lead, Antimony or the like can be preferably used.

  Examples of the unsaturated carboxylic acid ester containing active hydrogen include unsaturated carboxylic acid esters containing at least one functional group selected from a hydroxyl group, a carboxyl group, and an amino group. Moreover, as unsaturated carboxylic acid ester, monocarboxylic acid ester, such as acrylic acid and methacrylic acid, can be illustrated. More preferably, it is desirable to use a methacrylic acid ester and / or an acrylic acid ester containing a hydroxyl group and / or a carboxyl group. This unsaturated carboxylic acid ester containing active hydrogen is considered to act as a co-crosslinking agent in rubber vulcanization.

  The compounding quantity of unsaturated carboxylic acid ester containing active hydrogen shall be 1-50 mass parts. If the amount is less than 1 part by mass, the effect of reducing viscosity (improving processability) and the effect of improving adhesiveness are poor. On the other hand, if the amount exceeds 50 parts by mass, the hardness increases so much that the flexibility is significantly reduced. .

  Silica can be blended in the rubber composition. Silica is not limited to dry silica or wet silica. The compounding amount of silica is desirably 10 to 100 parts by mass with respect to 100 parts by mass of the rubber component containing H-NBR. When the blending amount is less than 10 parts by mass, the effect of improving the abrasion resistance and the effect of improving the adhesiveness are poor. On the other hand, when the amount exceeds 100 parts by mass, the rigidity of the rubber layer is increased, which causes a problem in the flexibility of the belt. is there.

  Furthermore, a silane coupling can be blended with the rubber composition. A known silane coupling agent can be used. Specifically, when a vinyltriethoxysilane oligomer is selected, it has excellent heat resistance and contains a vinyl group in the molecule. There is an effect that H-NBR and silica can be strongly bonded by crosslinking. In addition, since it has a much higher boiling point than other silane coupling agents (the boiling point of vinyltriethoxysilane monomer is about 150 ° C), it may dissipate during processing such as mixing, and before the crosslinking reaction As a result, the desired belt properties can be obtained in the present invention.

  The amount of the silane coupling agent is preferably 1 to 20 parts by mass with respect to 100 parts by mass of silica. If the amount is less than 1 part by mass, the effect of decreasing the viscosity is poor. On the other hand, if the amount exceeds 20 parts by mass, the vulcanized rubber becomes hard and the elongation decreases rapidly, resulting in a problem that the strength decreases.

  The rubber composition is desirably blended with an organic peroxide as a crosslinking agent. Examples of the organic peroxide include dicumyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, benzoyl peroxide, 1,3-bis (t-butylperoxyisopropyl) benzene, 2,5 -Dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5-dimethyl-2,5- (benzoylperoxy) hexane, 2,5-dimethyl-2,5-mono (t- Butyl peroxy) hexane and the like. The organic peroxide is desirably blended alone or as a mixture in an amount of 1 to 8 parts by mass, more preferably 1.5 to 4 parts by mass with respect to 100 parts by mass of the polymer component. In addition, it is also possible to use well-known crosslinking agents other than an organic peroxide.

  Furthermore, a metal hydroxide can be mix | blended with the said rubber composition. The blending amount is desirably 1 to 100 parts by weight, more preferably 10 to 60 parts by weight, based on 100 parts by weight of the rubber component. When the amount is less than 1 part by mass, the effect of improving adhesiveness is poor and there is a problem in durability. On the other hand, when the amount exceeds 100 parts by mass, the viscosity becomes extremely high, the flow is poor, and the shape of the mold does not appear. Specifically, in the case of a toothed belt, there is a problem that the tooth shape is lost. Examples of the metal hydroxide include magnesium hydroxide, aluminum hydroxide, calcium hydroxide, sodium hydroxide, and potassium hydroxide, and these can be used alone or in combination. Among these, aluminum hydroxide is desirable because it has a relatively low water absorption and high stability, and thus does not adversely affect physical properties such as processability, adhesion, and durability. The form of the metal hydroxide is not limited, but a powdered form is preferably used. In consideration of workability and the like, a metal hydroxide having a particle diameter of 0.5 to 60 μm is desirable.

  The rubber composition is preferably blended with 0.5 to 10 parts by mass of N, N'-m-phenylene dimaleimide with respect to 100 parts by mass of the polymer component. N, N'-m-phenylene dimaleimide acts as a co-crosslinking agent, and if it is less than 0.5 parts by mass, the effect of addition is not remarkable, and if it exceeds 10 parts by mass, the tearing force and adhesive force are rapidly reduced.

  In addition to the above, various additives can be added to the rubber composition as necessary. For example, carbon black, plasticizer, short fiber, crosslinking agent, anti-aging agent, heat resistance agent, tackifier, scorch inhibitor, crosslinking accelerator, acceleration aid, crosslinking retarder, colorant, UV absorber, flame retardant , Oil resistance improvers, and other fillers.

Carbon black is blended in order to maintain high properties such as belt hardness and modulus, and examples thereof include HAF, MAF, EPC, SAF, and ISAF. Among them, those having a nitrogen adsorption specific surface area of 40 to 120 m ² / g and a 24M4DBP oil absorption of 80 to 130 ml / 100 g are preferably used.

  As the short fiber, a short fiber having a length of about 1 to 10 mm made of a fiber such as cotton, polyester, polyamide, aramid, or PBO can be used. In addition, if a very short fiber with a special size having a diameter of 0.1 to 2.0 μm and a length of 10 μm to 1.0 m is used as a short fiber, the dispersibility and homogeneity are higher. Can be. The mixing amount of the short fibers is preferably mixed in the range of 1 to 30 parts by weight with respect to 100 parts by weight of the rubber. If the amount is less than 1 part by mass, the effect of improving the modulus of the short fiber cannot be sufficiently obtained, and if it exceeds 30 parts by mass, the hardness becomes too high, which is not preferable.

  The plasticizer improves the processability by blending and imparts flexibility to the belt. Examples include polydimethylsiloxane oil, diphenylsilanediol, trimethylsilanol, phthalic acid derivative phthalate, adipic acid derivative adipate, trimellitic acid derivative, sebacate, phosphate, and polyether. The blending amount of the plasticizer is 3 to 25 parts by mass, preferably 5 to 15 parts by mass. If it is less than 3 parts by mass, the processability cannot be improved sufficiently. On the other hand, if it exceeds 25 parts by mass, the strength is lowered and the plasticizer bleeds.

  Examples of the antioxidant include phenylenediamines, phosphates, quinolines, cresols, phenols, and dithiocarbamate metal salts.

  As an example of the transmission belt according to the present invention, a mesh transmission belt and a friction transmission belt are illustrated. Specifically, a sectional perspective view of the toothed belt 1 is shown in FIG. 1, and a sectional perspective view of the V-ribbed belt 10 is shown in FIG. Show.

  The toothed belt 1 in FIG. 1 has a belt body composed of a plurality of tooth portions 2 and a back portion 4 in which a core wire 3 is embedded along the belt longitudinal direction (arrow in the figure). A tooth cloth 5 is attached to the surface as necessary. Here, the transmission surface means a rubber layer constituting the tooth portion 2.

  In addition, when the toothed belt 1 is produced by the press-fitting molding method, the tooth portion 2 and the back portion 4 are formed from the same rubber composition sheet, so that the back portion 4 also has the same rubber layer as the tooth portion 2.

  The V-ribbed belt 10 shown in FIG. 2 includes an extended portion 12 made of a cover canvas 15, an adhesive portion 14 in which a core wire 13 is embedded, and a compression portion 16 that is an elastic layer below it. The compression portion 16 has a plurality of trapezoidal ribs having a substantially triangular cross section extending in the belt longitudinal direction. Here, the transmission surface refers to a rubber layer constituting the compression unit 16.

  The cores 3 and 13 used in the present invention are, for example, polyarylate fiber, polybutylene terephthalate (PBT) fiber, polyethylene terephthalate (PET) fiber, polytrimethylene terephthalate (PTT) fiber, polyethylene naphthalate (PEN) fiber, etc. Cords such as polyester fiber, aramid fiber, glass fiber, and carbon fiber can be used. The composition of the glass fiber may be either E glass or S glass (high-strength glass), and is not limited to the thickness of the filament, the number of converging filaments, and the number of strands.

  The cores 3 and 13 are preferably subjected to an adhesion treatment in order to improve adhesion to rubber. For example, (1) after impregnating the untreated cord into a tank containing a pretreatment liquid containing an epoxy compound, an isocyanate compound or the like and pre-dipping, (2) in a drying furnace set at a temperature of 160 to 200 ° C. (3) Subsequent immersion in a tank containing an RFL solution and (4) Pass through a stretching heat setting processor set at 210 to 350 ° C. for 30 to 600 seconds. -1 to 3% stretched to obtain a stretched cord, (5) immersed in a tank containing rubber paste, and (6) dried for 120 to 300 seconds through a drying oven set at 130 to 170 ° C. There are methods. Note that it is not necessary to perform all the steps (1) to (6), and it is also possible to perform only (1) to (4) as desired.

  Examples of the isocyanate compound used in this pretreatment liquid include 4,4′-diphenylmethane diisocyanate, tolylene 2,4-diisocyanate, polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, and polyaryl polyisocyanate (for example, PAPI as a trade name) ) Etc. This isocyanate compound is used by mixing with an organic solvent such as toluene or methyl ethyl ketone.

  In addition, blocked polyisocyanates in which the isocyanate group of the polyisocyanate is blocked by reacting the isocyanate compound with a blocking agent such as phenols, tertiary alcohols, and secondary alcohols can also be used.

  Examples of the epoxy compound include reaction products of polyhydric alcohols such as ethylene glycol, glycerin and pentaerythritol, polyalkylene glycols such as polyethylene glycol and halogen-containing epoxy compounds such as epichlorohydrin, resorcin, bis (4-hydroxy Phenyl) dimethylmethane, phenol. Formaldehyde resin, resorcin. Reaction products with polyhydric phenols such as formaldehyde resins and halogen-containing epoxy compounds. The epoxy compound is used by mixing with an organic solvent such as toluene or methyl ethyl ketone.

  The RFL treatment liquid is a mixture of resorcin and formaldehyde precondensate with rubber latex. In this case, the molar ratio of resorcin and formaldehyde is preferably 1: 2 to 2: 1 in order to increase the adhesive force. . If the molar ratio is less than 1/2, the three-dimensional reaction of resorcin-formaldehyde resin progresses too much and gels. On the other hand, if it exceeds 2/1, the reaction between resorcin and formaldehyde does not progress so much. To do. Examples of the rubber latex include styrene / butadiene / vinylpyridine terpolymer, H-NBR, chloroprene rubber, and nitrile rubber.

  The weight ratio of the solid content of the resorcin-formaldehyde initial condensate and the rubber latex is preferably 1: 2 to 1: 8. Maintaining this range is suitable for increasing the adhesive strength. When the above ratio is less than 1/2, the resin content of resorcin-formaldehyde increases, the RFL film becomes hard and dynamic adhesion deteriorates. On the other hand, when the ratio exceeds 1/8, the resin content of resorcin-formaldehyde Therefore, the RFL film becomes soft and the adhesive strength decreases.

  Furthermore, a crosslinking accelerator or a crosslinking agent may be added to the RFL solution, and the crosslinking accelerator to be added is a sulfur-containing crosslinking accelerator, specifically 2-mercaptobenzothiazole (M) or a salt thereof. (For example, zinc salt, sodium salt, cyclohexylamine salt, etc.) thiazoles such as dibenzothiazyl disulfide (DM), sulfenamides such as N-cyclohexyl-2-benzothiazylsulfenamide (CZ), tetramethyl Thiurams such as thiuram monosulfide (TS), tetramethylthiuram disulfide (TT), dipentamethylene thiuram tetrasulfide (TRA), sodium di-n-butyldithiocarbamate (TP), zinc dimethyldithiocarbamate (PZ) diethyldimethyl Dithiocarbamine such as zinc dithiocarbamate (EZ) There are salts and the like. Moreover, as a crosslinking agent, there exist sulfur, a metal oxide (zinc oxide, magnesium oxide, lead oxide), a peroxide, etc., and it uses together with the said crosslinking accelerator.

  Although it has been described that the rubber layer serving as the transmission surface of the transmission belt is composed of the rubber composition, it is needless to say that all the rubber compositions constituting the transmission belt body can be composed of the rubber composition. It is.

  In the toothed belt 1 shown in FIG. 1, the rubber layer serving as the transmission surface is the tooth portion 2, but the back portion 4 can also be composed of the rubber composition. It is also possible to configure the tooth part 2 with the rubber composition and the back part 4 with another rubber composition. For example, it is also possible to make the tooth | gear part 2 into a multilayer structure, and to comprise a surface layer with this rubber composition.

  In the V-ribbed belt 10 shown in FIG. 2, the rubber layer serving as the transmission surface is the compression portion 16, but the adhesive portion 12 can also be formed of the rubber composition. It is also possible to configure the compression portion 16 with the rubber composition and the bonding portion 12 with another rubber composition. For example, it is also possible to make the compression part 16 into a multilayer structure, and to comprise a surface layer with this rubber composition.

  When a rubber composition other than the above rubber composition is used for the belt main body, for example, a blend rubber obtained by mixing H-NBR and a partner rubber made of other kinds of rubber as a rubber component may be used. The partner rubber blended with H-NBR is ethylene / α-olefin elastomer, butadiene rubber (BR), styrene / butadiene rubber (SBR), nitrile rubber (NBR), chloroprene rubber (CR), butyl rubber (IIR), natural Mention may be made of rubber (NR).

  As the tooth cloth 5 that covers the tooth surface of the toothed belt 1, a canvas made of a plain woven fabric, a twill woven fabric, a satin woven fabric, or the like is used. As the wefts arranged in the belt longitudinal direction of these woven fabrics, for example, multifilament yarns obtained by converging filament base yarns of para-aramid fibers of 0.3 to 1.2 deniers are 20 to 80 of the total amount of wefts in the belt longitudinal direction. What contains the mass% is preferable.

  That is, the weft is a yarn including a multi-filament yarn of para-aramid fiber, and the multi-filament yarn of the para-aramid fiber can include a yarn made of a meta-aramid fiber. The specific configuration of the weft is a combination of three types of yarns, a multi-filament yarn of para-aramid fiber, a spun yarn made of meta-aramid fiber, and a urethane elastic yarn.

  Other specific wefts are composed of three types of yarns: multi-filament yarns of para-aramid fibers, aliphatic fiber yarns (6 nylon, 66 nylon, polyester, polyvinyl alcohol, etc.), and urethane elastic yarns. It may be twisted.

  The warp of the tooth cloth 5 is composed of filament yarns of aramid fibers made of para-type aramid fibers and meta-type aramid fibers, polyamide yarns such as 6 nylon, 6.6 nylon and 12 nylon, and filament yarns of polyvinyl alcohol and polyester. Preferably, if the filament yarn of aramid fiber is a multifilament yarn in which the filament yarn of para-aramid fiber is converged for the weft yarn 5, the rigidity balance is achieved and the tooth cloth becomes uniform in thickness.

  However, the materials of the warp and weft are not limited to these, and other forms include cords, non-woven fabrics, knitted fabrics and the like, and are not particularly limited. In addition, it is desirable that the tooth cloth is adhered with an adhesive rubber by soaking, spreading, coating, or the like.

  The cover canvas 15 used for the V-ribbed belt 10 is a fiber base selected from woven fabric, knitted fabric, non-woven fabric, and the like. Known and publicly used fiber materials can be used. For example, natural fibers such as cotton and hemp, inorganic fibers such as metal fibers and glass fibers, and polyamide, polyester, polyethylene, polyurethane, polystyrene, and polyfluoroethylene. , Organic fibers such as polyacryl, polyvinyl alcohol, wholly aromatic polyester, and aramid. In the case of a woven fabric, these yarns are woven by plain weaving, twill weaving, satin weaving or the like.

  The cover canvas 15 is preferably immersed in the RFL liquid according to a known technique. Further, after immersion in the RFL solution, friction can be performed by rubbing the uncrosslinked rubber against the cover canvas 15 or immersion can be performed in a soaking solution in which the rubber is dissolved in a solvent. The RFL solution may be appropriately mixed with a carbon black solution to blacken the treatment, or a known surfactant may be added in an amount of 0.1 to 5.0% by mass.

  The power transmission belt is not limited to the above-described toothed belt and V-ribbed belt, and a V belt, a flat belt, and the like also belong to the technical scope of the present invention.

  Further, the V-ribbed belt is not limited to the configuration as shown in FIG. 2, for example, a V-ribbed belt without an adhesive portion, a V-ribbed belt with a two-layer compression portion, and a rubber layer without a cover canvas attached to the back surface. V-ribbed belts and the like also belong to the technical scope of the present invention.

  Next, the manufacturing method of a toothed belt is demonstrated as a manufacturing method of the transmission belt of this invention. In addition, the manufacturing method of a toothed belt is not limited to the following.

  First, a canvas forming a tooth cloth is wound around a cylindrical mold having a plurality of recesses corresponding to the tooth portions of the toothed belt. Subsequently, the tensile body constituting the core wire is wound around the cylindrical mold around which the canvas is wound so as to have a predetermined pitch in the longitudinal direction of the cylindrical mold. Next, the rubber sheet which forms a back part and a tooth | gear part is wound, and an unbridged sleeve is formed. Then, the cylindrical mold around which the uncrosslinked sleeve is wound is transferred into a crosslinked can, and heated and pressurized, whereby the rubber sheet is pressed into the mold groove portion to form a tooth portion. Individual toothed belts are obtained by cutting the obtained sleeve-shaped molded body into a ring shape with a cutter according to a predetermined cut width.

  In the above method, a rubber composition containing 1 to 50 parts by mass of an unsaturated carboxylic acid ester containing active hydrogen and a crosslinking agent is subjected to a crosslinking reaction with respect to 100 parts by mass of a rubber component containing H-NBR. Thus, the transmission surface (here, the tooth portion) can be formed of a crosslinked product of the rubber composition. In addition, when an organic peroxide is selected as a crosslinking agent, the crosslinked product becomes an organic peroxide-based crosslinked product.

  Hereinafter, a description will be given with specific examples.

  The Mooney viscosity of the rubber compositions blended as shown in Table 1 and Table 2 was measured according to JIS K6300-1. Moreover, the physical property of the crosslinked rubber which was press-crosslinked at 165 ° C. for 30 minutes was evaluated. The hardness (JIS-A) of the obtained crosslinked rubber is JIS K6253, the elongation EB at break (perpendicular to the orientation direction of the short fibers) is JIS K6251 and the stress M100 at 100% elongation is JIS K6251. Measured accordingly. The DIN abrasion test was tested according to JIS K 6264, and a sample containing short fibers was prepared such that the short fibers were oriented perpendicular to the wear surface. The results are shown in Table 3.

  In Comparative Examples 1 and 2, the viscosity of the uncrosslinked rubber was higher than that in Examples in which the same polymer was blended, and the problem was not sufficient in processability. Also, satisfactory wear resistance was not obtained. Further, in Comparative Example 3, it was found that the degree of crosslinking was too high and EB was lowered. And in the comparative example 4, there existed a malfunction that hardness rose extremely. On the other hand, in the examples, it can be seen that the viscosity is moderately low, there is no problem in workability, and the hardness is high and the wear resistance is excellent.

  Next, a toothed belt was prepared using a rubber sheet containing the rubber shown in Table 1. In the toothed belt produced in this example, the toothed belt has a tooth part covered with a nylon tooth cloth, and a glass core wire is embedded in the main body. The belt size is tooth type: MY, number of teeth: 105, Belt width: 60 mm in size.

  Here, the tooth part and the back part were prepared from the rubber composition shown in Table 1, kneaded with a Banbury mixer, and then rolled with a calender roll.

  A nylon tooth cloth was wound around a tooth-shaped mold for forming a belt, and then a glass core wire subjected to adhesion treatment was wound around a spiral with a predetermined tension at a predetermined pitch. After pasting the rubber sheet of Table 1 on this core, it is put into a cross-linking can and pressure-crosslinked at 165 ° C for 30 minutes by a normal press-fitting method, and the back surface of the belt is polished to a certain thickness. Then, it was cut into a certain width to obtain a toothed belt.

  The toothed belt thus obtained was evaluated for adhesion and durability. For evaluation of adhesion, the adhesive strength of the back rubber was measured according to JIS K6256 and the peeled state was visually confirmed. As for the evaluation of durability, a running test under a high load of 15 kgf per 1 mm width of the belt was performed at an ambient temperature of 23 ° C. according to the layout shown in FIG. Note that this driving test is terminated in 300 hours. These results are shown in Table 3.

  As a result, since Comparative Example 1 was not sufficiently adhesive, peeling occurred between the tooth rubber and the core wire, and it was not possible to run until the cutoff time. Further, in Comparative Example 2, the tooth portion was severely worn and the belt durability was insufficient. In Comparative Example 3, it was found that the adhesive strength was low and the running life was short. In Comparative Example 4, there was a problem that the flexibility was remarkably lowered and the running life was shortened. On the other hand, it can be seen that in the examples, the adhesive strength was high and peeling from the core did not occur, the wear resistance was good, the teeth were less damaged, and the belt life was prolonged.

  The transmission belt according to the present invention can be attached to a drive device for automobiles or general industries.

It is a section perspective view of a toothed belt which is a power transmission belt concerning the present invention. It is a cross-sectional perspective view of the V-ribbed belt which is a power transmission belt which concerns on this invention. It is the layout of the testing machine used for evaluation of the endurance test of a toothed belt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Toothed belt 2 Tooth part 3 Core wire 4 Back part 5 Tooth cloth 10 V-ribbed belt 12 Extension part 13 Core wire 14 Bonding part 15 Cover canvas 16 Compression part

Claims (14)

  The transmission surface is composed of a crosslinked product of a rubber composition in which 1 to 50 parts by mass of an unsaturated carboxylic acid ester containing active hydrogen is added to 100 parts by mass of a rubber component containing hydrogenated nitrile rubber. A transmission belt characterized by   The transmission belt according to claim 1, wherein the unsaturated carboxylic acid ester is a methacrylic acid ester and / or an acrylic acid ester.   The power transmission belt according to claim 1, wherein the crosslinked product is an organic peroxide-based crosslinked product.   The rubber component is a blend of (i) a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt compound polymer and (b) a hydrogenated nitrile rubber. The transmission belt described.   The rubber component is a composite polymer obtained by blending (i) hydrogenated nitrile rubber and unsaturated carboxylic acid metal salt in a mass ratio of 30:70 to 70:30 and (b) hydrogenated nitrile rubber in a mass ratio of 10: The transmission belt according to claim 4, wherein the transmission belt is blended so as to be 90 to 60:40.   The power transmission belt according to any one of claims 1 to 5, wherein silica is blended in the rubber composition.   The power transmission belt according to claim 1, wherein the power transmission belt is a toothed belt.   A rubber composition in which a transmission surface of a transmission belt is blended with 1 to 50 parts by weight of an unsaturated carboxylic acid ester containing active hydrogen and 100 parts by weight of a rubber component containing hydrogenated nitrile rubber and a crosslinking agent. A method for producing a transmission belt, which is formed by crosslinking.   The method for producing a transmission belt according to claim 8, wherein the unsaturated carboxylic acid ester is a methacrylic acid ester and / or an acrylic acid ester.   The method for producing a transmission belt according to claim 8 or 9, wherein the crosslinking agent is an organic peroxide.   11. The rubber component according to any one of claims 8 to 10, wherein the rubber component is a mixture of (b) a hydrogenated nitrile rubber and a composite polymer body containing an unsaturated carboxylic acid metal salt and (b) a hydrogenated nitrile rubber. The manufacturing method of the transmission belt of description.   The rubber component is a composite polymer obtained by blending (i) hydrogenated nitrile rubber and unsaturated carboxylic acid metal salt in a mass ratio of 30:70 to 70:30 and (b) hydrogenated nitrile rubber in a mass ratio of 10: The method for manufacturing a power transmission belt according to claim 11, wherein the power transmission belt is blended so as to be 90-60: 40.   The method for producing a transmission belt according to any one of claims 8 to 12, wherein silica is blended in the rubber composition.   The method for manufacturing a transmission belt according to any one of claims 8 to 13, wherein the transmission belt is a toothed belt.

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