JP2005281629A - Rubber composition and transmission belt using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition which can improve heat resistance while it keeps abrasion resistance, and a transmission belt using the same. <P>SOLUTION: The rubber composition comprises 100 parts by mass of a halogen-containing raw rubber and 0.1-10 parts by mass of an aging-preventive agent comprising an aluminum salt of a 6-10C fatty acid. The transmission belt comprises a core string and a compressed rubber layer, wherein the rubber composition is used at least in the compressed rubber layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rubber composition and a transmission belt using the same, and more particularly to a rubber composition excellent in heat resistance and wear resistance and a transmission belt using the same.

  Conventionally, in various transmission belts such as a V-ribbed belt, a wrapped V-belt, a low-edge V-belt, a transmission belt, and a flat belt, a halogen element-containing polymer having excellent heat resistance, weather resistance, and ozone resistance as a rubber constituting the main body. A rubber composition using as a raw material rubber is frequently used.

  Among the transmission belts, the V-ribbed belt has been required to have further improved heat resistance as the automobile becomes more compact in recent years. As a rubber composition using a halogen element-containing polymer used as a raw rubber for the V-ribbed belt, a chloroprene rubber composition is most common. Conventionally, in order to increase the heat resistance of a chloroprene rubber composition, it is known that it is effective to appropriately select an anti-aging agent to be blended. Specifically, it is an anti-aging agent such as p- (p-toluenesulfonylamide) diphenylamine, dioctyldiphenylamine, dicumyldiphenylamine and the like.

  In Patent Document 1, phenyl-α-naphthylamine is blended with zinc powder as an anti-aging agent, and in Patent Document 2, 4,4 ′-(α, α-dimethylbenzyl) is used as an anti-aging agent. It has been proposed to improve the heat resistance of each chloroprene rubber composition by blending diphenylamine with zinc powder.

  However, the chloroprene rubber composition using the various anti-aging agents has a problem that although the heat resistance is improved, the wear resistance is lowered.

Japanese Patent Laid-Open No. 50-87437

Japanese Patent Publication No. 6-43518

The present invention has been made to solve such problems, and an object thereof is to provide a rubber composition for improving heat resistance while maintaining wear resistance, and a transmission belt using the same. To do.

  That is, the invention according to claim 1 of the present application is a rubber composition comprising an anti-aging agent comprising an aluminum salt of a fatty acid having 6 to 10 carbon atoms in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the raw rubber containing a halogen element. It is a thing.

  The invention according to claim 2 is an anti-aging agent comprising an aluminum salt of a fatty acid having 6 to 10 carbon atoms in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of a raw material rubber containing a halogen element, and an anti-aging of diphenylamine type It is a rubber composition containing an agent.

  The invention according to claim 3 is the rubber composition according to claim 1 or 2, wherein the fatty acid is octanoic acid.

  The invention according to claim 4 is the rubber composition according to any one of claims 1 to 3, wherein the raw material rubber containing a halogen element is chloroprene.

  According to a fifth aspect of the present invention, in the power transmission belt in which the core wire embedded in the belt longitudinal direction and the compressed rubber layer are arranged, at least the compressed rubber layer has a content of 0.1 with respect to 100 parts by mass of the raw material rubber containing a halogen element. It is a power transmission belt characterized by using a rubber composition containing an anti-aging agent composed of an aluminum salt of 10 to 10 parts by mass of a fatty acid having 6 to 10 carbon atoms.

  According to a sixth aspect of the present invention, in the power transmission belt in which the core wire embedded in the belt longitudinal direction and the compressed rubber layer are disposed, at least the compressed rubber layer has a content of 0.1 with respect to 100 parts by mass of the raw material rubber containing a halogen element. It is a power transmission belt characterized by using a rubber composition containing an anti-aging agent composed of an aluminum salt of 10 to 10 parts by mass of a fatty acid having 6 to 10 carbon atoms and a diphenylamine type anti-aging agent.

  The invention according to claim 7 is the power transmission belt according to claim 5 or 6, wherein the fatty acid is octanoic acid.

  The invention according to claim 8 is the power transmission belt according to any one of claims 5 to 7, wherein the raw material rubber containing the halogen element is chloroprene.

  A ninth aspect of the present invention is the transmission belt according to any one of the fifth to eighth aspects, wherein the compressed rubber layer is a V-ribbed belt having a plurality of rib portions extending in a belt longitudinal direction.

  According to the invention described in claims 1 to 4, the rubber composition having improved heat resistance without lowering the abrasion resistance by the action of the fatty acid metal salt-based anti-aging agent and the diphenylamine-based anti-aging agent. Can be provided. Moreover, according to invention of Claims 5-9, the power transmission belt which improved heat resistance, without reducing abrasion resistance using the said rubber composition can be provided.

Hereinafter, the rubber composition of the present invention and the transmission belt using the same will be described in detail.
The rubber composition of the present invention includes a raw rubber containing a halogen element as a raw rubber. Specific examples include chloroprene, epichlorohydrin, polyvinyl chloride, chlorinated polyethylene, chlorosulfonated polyethylene, alkylated chlorosulfonated polyethylene, etc. Among them, chloroprene or epichlorohydrin is most preferable.

  The rubber composition of the present invention is blended with at least a fatty acid metal salt-based antiaging agent as an antiaging agent. Here, as the fatty acid metal salt-based antioxidant, a fatty acid metal having 6 to 10 carbon atoms, that is, a metal salt of a fatty acid selected from hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, and decanoic acid is preferably used. . A fatty acid metal salt having 5 or less carbon atoms is likely to bloom, whereas a fatty acid metal salt having 11 or more carbon atoms has a reduced ratio of functional groups, so that a sufficient anti-aging effect cannot be obtained. As a metal type of the metal salt, aluminum is most preferable in order to prevent chlorine extraction of the raw rubber and to improve heat resistance.

  Fatty acid metal salt-based anti-aging agents can improve the heat resistance while maintaining the wear resistance of the rubber composition by blending 0.1 to 10 parts by mass with respect to 100 parts by mass of the raw rubber. it can. If the blending amount is less than 0.1 parts by mass, the effect of improving the heat resistance cannot be obtained sufficiently. There is.

  Anti-aging agents blended in the rubber composition of the present invention include fatty acid metal salt-based anti-aging agents and diphenylamine-based anti-aging agents used in combination with fatty acid metal salt-based anti-aging agents. Diphenylamine-based anti-aging agents include 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, dicumyldiphenylamine, styrenated diphenylmian, p- (p-toluenesulfonylamido) diphenylamine, octylated diphenylamine, p -Isopropoxydiphenylamine, p- (p-toluenesulfonylamide) -diphenylamine, etc. are used.

  The diphenylamine-based anti-aging agent is mixed with the fatty acid metal salt-based anti-aging agent so that the total compounding amount is 0.1 to 10 parts by mass with respect to 100 parts by mass of the raw rubber. The heat resistance can be improved while maintaining the wear resistance of the composition. A diphenylamine-based anti-aging agent is an anti-aging agent that has been conventionally formulated for the purpose of improving the heat resistance of rubber compositions, and is a diphenylamine-based anti-aging agent and a fatty acid metal salt that is effective in improving wear resistance. A rubber composition having desired wear resistance and heat resistance can be obtained by using together with a system anti-aging agent.

  In the rubber composition of the present invention, in addition to the raw material rubber and the anti-aging agent, a compounded in an ordinary rubber composition, that is, a vulcanizing agent such as sulfur and metal oxide, bismaleimide, ethylenethiourea, etc. Vulcanization accelerators, various carbon blacks, reinforcing agents such as silica, fillers such as calcium carbonate, softeners such as naphthenic and paraffinic oils, plasticizers such as dioctyl phthalate and dioctyl adipate, polyester, polyamide, aramid, Short fibers such as vinylon and cotton are blended.

  The method for kneading the various blends is not particularly limited, and a known method such as a Banbury mixer or a kneader may be used as appropriate.

  Next, a description will be given of a power transmission belt using a rubber composition composed of the above-described various compounds. The transmission belt of the present invention is a belt for friction transmission such as a V-ribbed belt, a V-belt, a transmission belt, and a flat belt, and is a transmission belt using the rubber composition in at least a compression rubber layer of these belts. Hereinafter, the V-ribbed belt will be described in detail.

  FIG. 1 is a cross-sectional perspective view of the V-ribbed belt of the present invention. The V-ribbed belt 1 has a core wire 3 made of a fiber cord made of polyester fiber, aramid fiber, glass fiber or the like embedded in an adhesive rubber layer 2 and has a compressed rubber layer 4 below it. The compressed rubber layer 4 is provided with a plurality of ribs having a substantially triangular cross section extending in the longitudinal direction of the belt, and a cover canvas 5 is laminated on the belt surface. The rubber composition of the present invention is used for at least the compressed rubber layer 4. Although there is no restriction | limiting in particular in the adhesive rubber layer 2, You may use the rubber composition of the same kind as the compression rubber layer 4. FIG.

  As the core 3, a cord made of polyester fiber, aramid fiber, glass fiber or the like that has been subjected to adhesion treatment to impart adhesion to rubber is used. As an adhesion treatment, after pretreatment with an epoxy or isocyanate compound as necessary, the cord is immersed in a resorcin-formaldehyde-latex (RFL) solution and then dried by heating to form a uniform adhesion layer on the surface. Is common. The cord subjected to the adhesion treatment is wound at a winding pitch of 1.0 to 1.3 mm, and the core wire 3 is formed.

  The cover canvas 5 is a canvas selected from a woven fabric, a knitted fabric, and a non-woven fabric. As fiber materials, natural fibers such as cotton and hemp, inorganic fibers such as metal fibers and glass fibers, and polyamide, polyester, polyethylene, polyurethane, polystyrene, polyfluoroethylene, polyacryl, polyvinyl alcohol, wholly aromatic polyester, Organic fibers such as aramid are listed. The cover canvas 5 is subjected to a friction process in which unvulcanized rubber is rubbed after being immersed in the RFL liquid, or a process in which the cover canvas 5 is immersed in a soaking liquid in which rubber is dissolved in a solvent.

  A typical manufacturing method of the V-ribbed belt is as follows. First, a canvas and an adhesive rubber layer are wound around the circumferential surface of a cylindrical molding drum, and then a cord is wound around the spiral in a predetermined pitch, and then an adhesive rubber layer and a compressed rubber layer are sequentially wound to obtain a laminate. Thereafter, this is vulcanized at a predetermined temperature and pressure to obtain a vulcanized sleeve.

  Next, the vulcanization sleeve is hung on the driving roll and the driven roll and travels under a predetermined tension, and the rotated grinding wheel is moved so as to contact the compressed rubber layer surface of the traveling vulcanization sleeve. Then, 3 to 100 plural groove-like portions serving as rib portions are formed at a time on the surface of the compressed rubber layer of the vulcanized sleeve. The vulcanized sleeve thus obtained is removed from the drive roll and the driven roll, is run on another drive roll and the driven roll, and is cut to a predetermined width by a cutter to obtain individual V-ribbed belts.

  Next, the rubber composition of the present invention and the transmission belt using the rubber composition will be described in detail with reference to examples. The blends shown in Table 1 were kneaded with a Banbury mixer and passed through an open roll, then vulcanized at 150 ° C. for 30 minutes, and the physical properties of the vulcanized rubber were measured. Anti-aging agents used are aluminum octanoic acid (anti-aging agent A), styrenated diphenylamine (anti-aging agent B), and dicumyl diphenylamine (anti-aging agent C). Further, a 3PK1100 size V-ribbed belt was prepared using cotton canvas, cords made of polyester fibers subjected to adhesion treatment, a sheet for compressed rubber layer and a sheet for adhesive rubber layer made of the composition shown in Table 1, and shown in FIG. 2 at room temperature. A 24 hour wear test was performed with the layout shown. The results are shown in Table 1.

  In Examples 1 to 3, due to the effects of an anti-aging agent composed of aluminum octanoic acid and an anti-aging agent based on siphenylamine, there was little decrease in elongation at break after 120 ° C. × 7 days, and the wear rate after running the belt was small. It has become. On the other hand, in Comparative Example 1, due to the effect of dicumyldiphenylamine, the decrease in elongation at break after heat aging was small, but the modulus was decreased, and as a result, the wear rate after running the belt was increased. Moreover, since the comparative example 2 was not mix | blended with the antioxidant, the breaking elongation after 120 degreeC x 7 days became small.

  It is a rubber composition that is effectively applied to an application that requires both heat resistance and wear resistance, particularly a friction transmission belt, and its friction transmission belt, particularly a V-ribbed belt for automobiles.

It is a cross-sectional perspective view of the V-ribbed belt of the present invention. FIG. 6 is a schematic diagram showing a layout of an abrasion test.

Explanation of symbols

1 V-ribbed belt 2 Adhesive rubber layer 3 Core wire 4 Compression rubber layer 5 Cover canvas

Claims (9)

A rubber composition comprising an antioxidant, comprising an aluminum salt of a fatty acid having 6 to 10 carbon atoms in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of a raw rubber containing a halogen element. A rubber composition comprising an anti-aging agent comprising an aluminum salt of a fatty acid having 6 to 10 carbon atoms in an amount of 0.1 to 10 parts by mass and 100 parts by mass of a raw material rubber containing a halogen element, and a diphenylamine-based anti-aging agent. The rubber composition according to claim 1, wherein the fatty acid is octanoic acid. The rubber composition according to any one of claims 1 to 3, wherein the raw rubber containing a halogen element is chloroprene. In the power transmission belt in which the core wire embedded in the belt longitudinal direction and the compressed rubber layer are arranged, at least the compressed rubber layer has a carbon number of 0.1 to 10 parts by mass with respect to 100 parts by mass of the raw rubber containing the halogen element. A power transmission belt comprising a rubber composition containing an anti-aging agent comprising an aluminum salt of a fatty acid of 10 or less. In the power transmission belt in which the core wire embedded in the belt longitudinal direction and the compressed rubber layer are arranged, at least the compressed rubber layer has a carbon number of 0.1 to 10 parts by mass with respect to 100 parts by mass of the raw rubber containing the halogen element. A power transmission belt comprising a rubber composition comprising an anti-aging agent comprising an aluminum salt of a fatty acid of 10 or less and a diphenylamine-based anti-aging agent. The power transmission belt according to claim 5 or 6, wherein the fatty acid is octanoic acid. The power transmission belt according to any one of claims 5 to 7, wherein the raw rubber containing the halogen element is chloroprene. The power transmission belt according to any one of claims 5 to 8, which is a V-ribbed belt having a plurality of rib portions extending in a belt longitudinal direction on the compressed rubber layer.

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