巴西专利BR112015024499B1 POWER TRANSMISSION BELT

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专利摘要:
transmission belt The present invention relates to a power transmission belt which contains a traction member extending in a direction along the belt length, an adhesion rubber layer in contact with at least a portion of the belt member. traction, a compression rubber layer formed on one surface of the adhesion rubber layer, and a traction rubber layer formed on the other surface of the adhesion rubber layer, wherein the rubber layer is formed of a rubber composition. vulcanized containing a rubber component, a polyolefin resin and a reinforcement material, the rubber component contains a chloroprene rubber and the reinforcement material contains a short fiber.
公开号:BR112015024499B1
申请号:R112015024499-8
申请日:2014-03-27
公开日:2021-06-01
发明作者:Hisato Ishiguro；Keiji Takano；Yoshihiro Miura
申请人:Mitsuboshi Belting Ltd；
IPC主号:

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Technical Field
[0001] The present invention relates to a power transmission belt, such as a V-belt or a ribbed V-belt, and, in detail, relates to a power transmission belt excellent in performance of durability and transmission efficiency. Background Technique
[0002] Conventionally, in order to improve the lateral pressure resistance of a power transmission belt, such as a V-belt or a ribbed V-belt, short fibers are added as a reinforcing material to a rubber layer of compression. For example, PTL 1 exposes a rubber V-belt in which a band is provided with an adhesive elastic body layer having a traction member embedded therein and elastic retaining body layers (compression rubber layers) located on sides top and bottom of the adhesive elastic body layer, the elastic retaining body layer comprises a chloroprene rubber, a reinforcing filler, a metal oxide vulcanizing agent, bismaleimide and short aramid fibers, and the short aramid fibers are arranged in a strap width direction. In this patent literature, the elastic modulus in a grain direction (an orientation direction of the short fibers) is increased by the arrangement of the short aramid fibers, thereby maintaining a resistance to lateral pressure, and durability is improved.
[0003] PTL 2 exposes a power transmission V-belt, in which the rubber hardness of at least one traction rubber layer and a compression rubber layer is regulated to a range from 90 to 96° , a rubber hardness of an adhesion rubber layer is set to a range of 83 to 89°, and the short aramid fibers are arranged in a belt width direction in the traction rubber layer and in the rubber layer. compression. This patent literature prevents the occurrence of cracking and separation (peeling) of a traction member from each layer of rubber at an early stage, and improves lateral pressure resistance, thereby improving a high load-transmitting capacity. .
[0004] In recent years, a power transmission belt is required to improve fuel economy properties, in order to improve fuel economy performance by reducing the transmission loss of one belt, another in addition the resistance to lateral pressure described above and the durability. For example, PTL 2 describes in paragraph [0005] that when the rubber hardness of the belt is increased, the bending stiffness is increased and, as a result, a loss of transmission occurs at a small pulley diameter. For this reason, an attempt is made to suppress a transmission loss by provision of teeth on an inner circumferential side or on both an inner circumferential side and an outer circumferential side (rear face side) of a V-band, to decrease the flexural stiffness of a belt. A V brace with teeth is generally known as the V brace of this type.
[0005] For the improvement of lateral pressure resistance and durability, it is an effective means to increase the amounts of reinforcing material, such as short high modulus fibers, such as aramid fibers or carbon black, thereby increasing the rubber hardness as described in the patent literatures described above. However, the increase in rubber hardness leads to increased flexural stiffness of a belt, resulting in decreased bending fatigue performance and increased belt transmission loss at a small pulley diameter, and this leads to decreased fuel saving properties. On the other hand, when the rubber hardness is lowered, in order to improve bending fatigue performance and fuel saving properties, a lateral pressure is decreased, and a belt is likely to soon reach the end of the life of it. That is, a series of lateral pressure resistance and durability characteristics are in a compromise relationship with a series of flexural fatigue performance characteristics and fuel economy properties. The flexural fatigue performance and fuel saving properties can be improved by the provision of teeth on an inner circumferential side or on both an inner circumferential side and an outer circumferential side of a V-belt. while the rubber hardness is increased for the purpose of maintaining lateral pressure resistance and durability, there is a situation where the fuel saving properties are still not sufficient. For this reason, a preferred rubber composition (particularly a rubber composition of a compression rubber layer) is desired.
[0006] There is a variable speed belt used in a continuously variable transmission like the V-belt of this type. In order to change a transmission gear ratio (a speed ratio between a drive pulley and a driven pulley) on the variable speed belt, the belt moves up and down (or back and forth) and a pulley radius steering on the pulley. If this movement is not conducted smoothly, a shear force from the pulley will act strongly, and as a result, peeling will occur between rubber layers (an adhesion rubber layer and a compression rubber layer) or between a layer rubber adhesion and a tensile member, and fuel saving properties (not fuel saving properties due to bending stiffness, but fuel saving properties based on decreased slip properties ) are decreased. To respond to this, an attempt is made to reduce a coefficient of friction and improve slip properties by adding large amounts of a reinforcing material such as short fibers or carbon black to increase rubber hardness, or by projecting short fibers from a frictional power transmission surface. However, the coexistence of durability performance (resistance to lateral pressure and durability) and transmission efficiency (fuel saving properties), which are in a compromise relationship with each other, is not sufficiently established.
[0007] PTL 3 exposes a frictional power transmission belt, in which a belt body is wound so as to make contact with the pulleys for power transmission, wherein at least a pulley contact portion of the belt is formed from a rubber composition containing an ethylene-a±-olefin elastomer and a powdered or granular polyolefin resin contained therein. This patent literature aims to improve low sound generation properties and abrasion resistance by mixing a powdered or granular polyolefin resin with short fibers that cannot be mixed in a large amount due to the uniformity of a composition. and at material costs. In the examples of this patent literature, a rubber composition containing 75 parts by mass of carbon black and 25 parts by mass of short nylon fibers mixed with 100 parts by mass of chloroprene rubber is prepared. However, this composition is described as a comparative example in which a sound pressure is high and the abrasion loss is large.
[0008] However, this patent literature does not describe fuel economy properties and, additionally, although this belt is applied to a variable speed belt requiring fuel economy properties, the fuel economy properties were low and durability was also low.
[0009] Additional prior art documents include document US 2004/214676 A1 which describes a friction forced power transmission belt which transmits power to a pulley with its belt body wound and in contact with the pulley where at least one belt body contact portion with a pulley is formed of a rubber composition in which a powdered or granular polyolefin resin is contained in ethylene alpha olefin elastomer.
[0010] The document US 2010/167861 A1 describes a friction transmission belt which comprises a compressed rubber layer containing ethylene alpha olefin elastomer, a short fiber and silica, having a single layer structure. This belt is said to inhibit noise resulting from slippage caused when the friction drive section of the belt is covered with water and is supposed to have excellent fatigue resistance characteristics.
[0011] US 2008/286529 A1 describes a power transmission belt having a body made at least in part from ethylene alpha olefin rubber. At least one load-bearing member is embedded in the ethylene alpha olefin rubber. First, second and third films are formed on the load-bearing member. The first film is made from at least one isocyanate compound and an epoxy compound, the second film is formed from polybutadiene rubber, and the third film is formed from an ethylene-propylene-diene terpolymer.
[0012] Citation List Patent Literature
[0013] PTL 1: JP-B-H05-63656PTL 2: JP-A-H10-238596PTL 3: JP-A-2004-324794 Invention Summary Technical Problem
[0014] Therefore, an object of the present invention is to provide a power transmission belt that can improve lateral pressure resistance and durability, while maintaining fuel economy properties.
[0015] Another objective of the present invention is to provide a power transmission belt in which, although the proportion of a reinforcing material, such as short fibers, is small, the transmission efficiency change after a stroke is small and the durability under a high temperature environment can be improved. Solution to Problem
[0016] As a result of intensive investigations to achieve the above objectives, the present inventors have found that when a compression rubber layer of a power transmission belt is formed by a vulcanized rubber composition, a polyolefin resin and fibers Short, side pressure resistance and durability can be improved while maintaining fuel saving properties, and completed the present invention.
[0017] That is, the conveying direction of the present invention contains: a traction member that extends a distance along the length of the strap; an adhesion rubber layer in contact with at least a portion of the traction member; a compression rubber layer formed on a surface of the adhesion rubber layer; and a traction rubber layer formed on the other surface of the adhesion rubber layer, wherein the compression rubber layer is formed of a vulcanized rubber composition containing a rubber component, a polyolefin resin and a reinforcing material, the rubber component contains a chloroprene rubber, and the reinforcing material contains a short fiber.
[0018] The reinforcing material may have a ratio of 80 parts by mass or less per 100 parts by mass of the rubber component. The polyolefin resin can have a ratio of 5 to 40 parts by mass per 100 parts by mass of rubber component. The polyolefin resin can have a ratio of 15 to 50 parts by mass per 100 parts by mass of reinforcing material. Short fiber can have a ratio of 15 to 25 parts by mass per 100 parts by mass of the rubber component. The reinforcing material may contain a short aramid fiber and a carbon black. The polyolefin resin can have an average molecular weight from 200,000 to 6,000,000 in a method measured in accordance with ASTM D 4020. A polyolefin resin feedstock can have an average particle diameter of 25 to 200 µm . The polyolefin resin in the compression rubber layer can have a long thin shape having an aspect ratio of 1.6 to 10, a major axis direction can be oriented substantially parallel to a belt width direction, and a direction Minor axis can be oriented substantially parallel to the direction along the length of the strap. Polyolefin resin can be exposed on a surface of the compression rubber layer. Polyolefin can have an area of occupancy from 0.2 to 30% on a surface of the compression rubber layer. The power transmission belt of the present invention can be a belt used in a continuously variable transmission. Advantageous Effects of the Invention
[0019] In the present invention, due to the fact that a rubber compression layer of a power transmission belt is formed by a vulcanized rubber composition containing chloroprene rubber, a polyolefin resin and a short fiber, the pressure resistance side and durability can be improved while maintaining fuel-saving properties. Furthermore, although the proportion of a reinforcing material such as short fibers is small, the change in transmission efficiency after one stroke is small, and durability under a high pressure environment can be improved. Brief Description of Drawings
[0020] Figure 1 is a schematic cross-sectional view illustrating an example of a power transmission belt.
[0021] Figure 2 is a schematic view for explaining a method of measuring transmission efficiency.
[0022] Figure 3 is a schematic view for explaining a method of measuring bending stress in the Examples.
[0023] Figure 4 is a schematic view for explaining a friction coefficient measurement method in the Examples.
[0024] Figure 5 is a schematic view for explaining a high load stroke test in the Examples.
[0025] Figure 6 is a schematic view for explaining a high speed stroke test in the Examples.
[0026] Figure 7 is a schematic view for explaining a stroke durability test in the Examples.
[0027] Figure 8 is a view showing a scanning electron micrograph of a cross section of a rubber band compression layer obtained in Example 3. Description of Modalities Rubber compression layer
[0028] The power transmission belt of the present invention is provided with a traction member extending in a direction along the strap length, an adhesion rubber layer in contact with at least a part of the traction member, a compression rubber layer formed on one surface of the adhesion rubber layer, and a traction rubber layer formed on the other surface of the adhesion rubber layer, and the compression rubber layer is formed by a vulcanized rubber composition containing a rubber component, a polyolefin resin and a reinforcing material. rubber component
[0029] In the present invention, the rubber component contains chloroprene rubber from the viewpoint that durability can be improved. Like chloroprene rubber, use can be made of conventional chloroprene rubbers.
[0030] Chloroprene rubber contains a trans-1,4 bond which has a relatively high stereoregularity as a main unit, and may further contain a cis-1,2 bond and a small amount of a 1.2 or 3.4 bond. . The trans-1,4 binding ratio may be 85% or more, and the cis-1.2 binding ratio may be 10% or more.
[0031] The glass transition temperature of the chloroprene rubber can be, for example, from -50 to -20°C, and is preferably from -40 to -20°C.
[0032] The chloroprene rubber may be of a sulfur-modified type and may be of a non-sulfur-modified type.
[0033] The rubber component may also contain another vulcanizable or crosslinkable rubber component. Examples of other vulcanizable or crosslinkable rubber component include other diene rubbers (e.g., natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (rubber of nitrile), hydrogenated nitrile rubber, etc.), ethylene-α-olefin elastomer, chlorosulfonated polyethylene rubber, alkylated chlorosulfonated polyethylene rubber, epichlorohydrin rubber, acrylic rubber, silicone rubber, urethane rubber and fluorine rubber . These rubber components can be used alone or in combination of two or more types of them.
[0034] The proportion of chloroprene rubber in the rubber component can be around 50% by mass or more (particularly 80 to 100% by mass), and only chloroprene rubber (100% by mass) is particularly preferred. Polyolefin resin
[0035] In the present invention, by mixing a polyolefin resin with the vulcanized rubber composition of the compression rubber layer, a coefficient of friction of the compression rubber layer is decreased and an abrasion resistance of the belt can be improved. Generally, in order to improve fuel economy properties, a coefficient of friction is lowered by adding excessively short fibers. However, cracks easily occur at the interface between the rubber component and the short fibers, and there is a possibility that durability will be impaired. On the other hand, when a polyolefin resin is added in place of increasing the amount of short fibers, since the polyolefin resin has a relatively low specific weight, the coefficient of friction can be lowered even by a small addition, and this can contribute to fuel economy properties. Particularly, when the short fibers are worn by friction with the course of the belt, the coefficient of friction is increased. However, the increase in the coefficient of friction can be suppressed by the presence of a polyolefin resin, although the short fibers are worn by friction, and the fuel saving properties can be maintained for a long period of time. Furthermore, the proper hardness needed for durability can be obtained by adding an appropriate amount of a polyolefin resin. Additionally, the short fiber volume ratio is decreased by the use of short fibers in combination with a polyolefin resin, and cracks at the interface between rubber and short fibers, which are a defect when a large amount of short fibers has been added , can be deleted. In detail, the polyolefin resin becomes flexible due to the heat generated during the course, and although peeling (fine cracks) occurs at the interface between the rubber and the short fibers, the polyolefin resin dispersed closely facilitates a stress concentration ( has a dampening role), and can suppress crack growth. Particularly, polyolefin resin plays a role as a reinforcing material by a small addition, differing from a reinforcing material such as short fibers and carbon black. It is assumed that, in the present invention by combining these actions, a lateral pressure resistance stiffness can be increased and durability can be improved, while improving the maintenance of fuel saving properties.
[0036] Polyolefin resin is relatively inexpensive in material cost compared to short fibers that are produced by cutting long fibers and still require an adhesive treatment to impart adhesiveness to a rubber. Therefore, it is also excellent in economic efficiency that the proportion of short fibers can be suppressed.
[0037] The polyolefin resin can be a polymer containing an α-polyolefin, such as ethylene, propylene, 1-butene, 2-butene, 1-pentene, 1-hexene, 3-methylpentene, or 4-methylpentene (particularly, an α-C2-6 polyolefin such as ethylene or propylene) as a major polymerization component.
[0038] Examples of a copolymerizable monomer other than a-polyolefin include (meth)acrylic monomers [for example, C1-6 alkyl (meth)acrylate, such as methyl (meth)acrylate or alkyl (meth)acrylate ], unsaturated carboxylic acids (eg maleic anhydride), vinyl esters (eg vinyl acetate or vinyl propionate), and dienes (such as butadiene or isoprene, etc.). These monomers can be used alone or in combination of two or more types of them.
[0039] Examples of polyolefin resin include polyethylene resins and polypropylene resins (such as polypropylene, propylene-ethylene copolymer, propylene-butene-1 copolymer or propylene-ethylene-butene-1 copolymer, etc.). Those polyolefins can be used alone or in combination of two or more types thereof.
Of those polyolefin resins polyethylene resins and polyethylene resins are preferred, and polyethylene resins are preferred from the viewpoint that the reducing effect of a coefficient of friction is large.
[0041] The polyethylene resin can be a polyethylene homopolymer (homopolymer), and it can be a polyethylene copolymer (copolymer). Examples of a copolymerizable monomer contained in the copolymer include olefins (for example, an α-C3-8 olefin such as propylene, 1-butene, 2-butene, 1-pentene, 1-hexene, 3-methylpentene, 4-methylpentene or 1-octene), (meth)acrylic monomers (for example, C1-6 alkyl (meth)acrylate, such as methyl (meth)acrylate or alkyl (meth)acrylate), unsaturated carboxylic acids (for example, maleic anhydride ), vinyl esters (for example vinyl acetate or vinyl propionate), and dienes (such as butadiene or isoprene, etc.). These monomers can be used alone or in combination of two or more types of them. Of those copolymerizable monomers, α-Cs-8 olefins, such as propylene, 1-butene, 1-hexene, 4-methylpentene and 1-octene, are preferred. The proportion of the copolymerizable monomer is preferably 30% by molecule or less (eg from 0.01 to 30% by mol), more preferably 20% by mol or less (eg from 0.1 to 20% by mol), and even more preferably by 10% by mol or less (eg from 1 to 10% by mol). The copolymer can be a random copolymer, a block copolymer or the like.
[0042] Examples of polyethylene resin include low, medium or high density polyethylene, linear low density polyethylene, ultra high molecular weight polyethylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene copolymer -propylene-butene-1, and ethylene-(4-methylpentene-1) copolymer. These polyethylene resins can be used alone or in combination of two or more types thereof. Of those polyolefin resins, ultra high molecular weight polyethylene is particularly preferred from a standpoint that the durability of a belt can be improved.
[0043] The average molecular weight of the polyolefin resin (particularly polyethylene resin) can be selected from a range, for example, from 10,000 to 12,000,000 in a method measured in accordance with ASTM D 4020. The lower limit it can be, for example, 50,000 or more or 100,000 or more, and is preferably 200,000 or more, more preferably 500,000 or more, and particularly preferably 1,000,000 or more. The upper limit of the average molecular weight may be, for example, 10,000,000 or less or 8,500,000 or less, and preferably is 8,000,000 or less, more preferably 7,500,000 or less, even more preferably 7,000 .000 or less and, particularly preferably, 6,000,000 or less. When the molecular weight is too small, mechanical properties and heat resistance are decreased and, in addition, a coefficient of friction becomes too large, thus an abrasion loss is increased and there is a concern that durability is decreased. On the other hand, when it is too big, the bending properties of a belt are diminished, thereby durability is diminished, and additionally a friction coefficient becomes too small, and a belt is easy to slip.
[0044] It is preferred that the polyolefin resin be substantially uniformly dispersed in a vulcanized rubber composition in a prescribed size. The shape of the polyolefin resin in the vulcanized rubber composition is either a spherical shape or a long slender shape (stem shape or fiber shape). The average diameter of a major axis thereof can be, for example, 5 to 500 µm (eg from 10 to 500 µm), and is preferably from 20 to 500 µm (eg from 30 to 500 µm), and more preferably from 100 to 300 µm (particularly from 150 to 250 µm). The average diameter of a minor axis can be, for example, from 30 to 500 µm (eg from 30 to 400 µm), and is preferably from 30 to 350 µm (eg from from 30 to 300 μm), and more preferably from 50 to 200 μm (particularly from 70 to 150 μm). The aspect ratio (mean diameter of major axis / average diameter of minor axis) can be, for example, from 1 to 16 (for example, from 1.4 to 14), and is preferably from from 1.6 to 12 (eg from 1.6 to 10), and more preferably from 1.7 to 5 (eg from 1.8 to 3). In the present invention, in the case where the polyolefin resin is strongly embedded and dispersed in a rubber in the state of being deformed into a long slender shape (eg a potato shape type shape) by using an anchoring effect on the compression rubber layer, the polyolefin resin is further suppressed from falling off the surface of the compression rubber layer, and fuel saving properties can be maintained for a longer period of time, which is preferred.
[0045] The polyolefin resin having the long thin shape is obtained in such a way that a granular polyolefin polymer having a substantially isotropic shape (e.g. a substantially spherical shape, a polyhedron shape or an undefined shape) receives a force of shear in the state of being softened by the heat generated in the rubber composition in the course of being kneaded into the rubber composition and deforms into a long slender shape. The average particle diameter (primary particle diameter) of a raw material, before a deformation, can be, for example, from 10 to 300 µm, and preferably is from 20 to 250 µm, and more preferably, from 25 to 200 μm (particularly from 50 to 150 μm). When the particle diameter is too small, economic efficiency is decreased; and when it is too large, even dispersion in the composition becomes difficult, and durability is diminished by decreasing abrasion resistance.
[0046] It is preferred that polyolefin resin having a long slender shape is embedded so that a larger axis orients substantially parallel with a belt width direction and a smaller axis orients substantially parallel to a direction in the direction the length (circumferential direction) of the strap. Due to the fact that rubber requires flexibility in the lengthwise direction, the decrease in strap flexibility can be suppressed by guiding a larger axis direction of the polyolefin resin which decreases the flexibility of the rubber to the strap width direction. . More so, due to the fact that the minor axis side (edge of a major axis direction) of the polyolefin resin is exposed on the surface of the compression rubber layer (frictional power transmission surface) by the direction orientation of smaller geometric axis with a direction in the belt length direction, the polyolefin resin is strongly embedded in the layer and the polyolefin resin is difficult to fall off, although the friction power transmission surface slides with pulleys. A general method for making a polyolefin resin's major axis direction orient towards a rubber width direction is, for example, a roller bearing method.
[0047] In the present invention, an average diameter of a major axis and a minor axis, and an average particle diameter can be measured by a Soft measurement ("analySIS", manufactured by Soft Imaging System) from an image observed with a scanning electron microscope.
[0048] The melting point (or softening point) of the polyolefin resin can be, for example, from 10 to 300°C, and preferably is from 20 to 275°C, and more preferably from around 30 to 250°C. When the melting point is too high, it becomes difficult to deform it into a long slender shape in a kneading process; and when it's too low, durability can be decreased.
[0049] In order to decrease a friction coefficient and improve fuel consumption saving properties, it is preferred that the polyolefin resin is exposed on the surface of the compression rubber layer (friction power transmission surface). The area occupied by the polyolefin resin on the frictional power transmission surface may be, for example, from 0.1 to 40% (for example, from 0.2 to 30%), and preferably is from 0.5 to 25 % (eg 1 to 20%), and more preferably around 3 to 15% (particularly 5 to 10%). When the area occupied by the polyolefin resin is too small, the effect of reducing a coefficient of friction is small; and, when it is too great, a coefficient of friction is excessively diminished, and a slip becomes easy to occur. In the present invention, the area ratio occupied by the polyolefin resin is obtained by observing the surface of a frictional power transmission surface by a scanning electron microscope for confirmation of a phase separation structure of the rubber and resin of polyolefin, and with respect to the phase formed of the polyolefin resin, calculating the area occupied by the phase formed of the polyolefin resin by a Soft measurement (“analySIS”, manufactured by the Soft Imaging System).
[0050] The phase structure of the polyolefin resin on the frictional power transmission surface is not particularly limited as long as it is adhered in the above area ratio. It can be any one of a sea and island phase separation structure, in which an island phase is formed of polyolefin resin and short fibers, and a sea and island phase separation structure, in which the island phase it is made up of a rubber component and short fibers. Those phase separation structures can be controlled by mainly adjusting the proportion of the polyolefin resin, but the sea and island phase separation structure, in which the polyolefin resin is an island phase, is preferred from a standpoint. that it is possible to adjust an appropriate coefficient of friction.
[0051] The proportion of polyolefin resin can be selected from a range of around 0.1 to 50 parts by mass per 100 parts by mass of the rubber component from a point of view of both mechanical characteristics, such as resistance to lateral pressure and fuel saving properties can be obtained. The lower limit may be, for example, 1 part by mass or more, and preferably is 3 parts by mass or more, more preferably 5 parts by mass or more, and particularly preferably 10 parts by mass or more . The upper limit of the proportion of polyolefin resin may be, for example, 45 parts by mass or less, and preferably is 40 parts by mass or less, more preferably 30 parts by mass or less per 100 parts by mass of the rubber component.
[0052] Furthermore, the proportion of the polyolefin resin can be selected from a range of around 1 to 100 parts by mass, and may be, for example, from 5 to 90 parts by mass, and is preferably of 10 to 80 parts by mass, and more preferably around 15 to 50 parts by mass (particularly 20 to 40 parts by mass), per 100 parts by mass of the following reinforcement material.
[0053] When the proportion of polyolefin resin is too small, the projection of the polyolefin resin in the rubber layer is decreased, and the effect of reducing a coefficient of friction is decreased.
[0054] On the other hand, when the proportion of polyolefin resin is too large, a coefficient of friction is excessively decreased and, as a result, a belt slips, and a flexural fatigue strength of the compression rubber layer is decreased ( because the compression rubber layer becomes rigid and the bending stress is increased). As a result, a bending loss is increased in the state where a belt winding diameter is small, and fuel economy properties are decreased. Furthermore, the dispersibility of the polyolefin resin is decreased, to cause poor dispersion, and there is a possibility of cracks being generated in the compression rubber layer in an initial state from the portions as the starting point. Reinforcement material
[0055] The reinforcing material contains at least short fibers. Examples of short fibers include synthetic fibers such as polyolefin fibers (such as a polyethylene fiber and a polypropylene fiber, etc.), polyamide fibers (such as polyamide 6 fiber, polyamide 66 fiber and polyamide fiber 46, etc.), polyalkylene arylate fibers (such as C24 arylate C6-14 alkylene fibers, such as polyethylene terephthalate (PET) fiber and polyethylene naphthalate (PEN) fibers, etc.), polyethylene fibers vinylon, polyvinyl alcohol fibers and polyparaphenylene benzobisoxazole (PBO) fibers; and inorganic fibers such as carbon fibers. These short fibers can be used alone or in a combination of two or more types of them. Of these short fibers, synthetic fibers and natural fibers, particularly synthetic fibers (such as polyamide fibers and polyalkylene arylate fibers) are preferred and, above all, short fibers containing at least aramid fibers are preferred from one point view that a coefficient of friction can be reduced while maintaining flexibility and resistance to lateral pressure.
Examples of short aramid fibers include a polyparaphenylene terephthalamide fiber (eg, "TWARON" (trademark)" manufactured by Teijin Limited, and "KEVLAR (trademark)" manufactured by Du Pont-Toray Co. , Ltd.), a copolymer fiber of polyparaphenylene terephthalamide and 3,4'-oxydiphenylene terephthalamide (eg, "TECHNORA (trademark)" manufactured by Teijin Limited), and a polymetaphenylene isophthalamide fiber that is of meta type (for example, “CONEX (trademark)” manufactured by Teijin Limited) and “NOMEX (trademark)” manufactured by Du-Pont). These short aramid fibers can be used alone or in a combination of two types or more of them.
[0057] In order to suppress a deformation by compression of a belt against a pressing force of pulleys, the short fibers are embedded in the compression rubber layer by being made to orient in a belt width direction. A general method for making short fibers orient in a belt width direction is, for example, a roller bearing method. By projecting the short fibers from the surface of the compression rubber layer, a surface friction coefficient is reduced, thereby suppressing noise (sound generation), and abrasion due to rubbing with pulleys can be reduced. The average length of the short fibers can be, for example, from 1 to 20 mm, preferably is from 2 to 15 mm, and more preferably from 3 to 10 mm, and can be around 1 to 5 mm (and 2 to 4 mm). When the average length of the short fibers is too short, the mechanical characteristics (eg a modulus) in one grain direction cannot be sufficiently increased; and when it is too long, poor dispersion of the short fibers in the rubber composition occurs, thereby generating cracks in the rubber, and there is a possibility of a belt being damaged at an early stage. The average fiber diameter can be, for example, from 5 to 50 µm, and is preferably from 7 to 40 µm, and more preferably from around 10 to 35 µm.
[0058] The proportion of short fibers can be, for example, from 10 to 40 parts by mass, and preferably is from 12 to 35 parts by mass, and more preferably from around 13 to 30 parts by mass (particularly , 15 to 25 parts by mass) per 100 parts by mass of the rubber component. When the proportion of short fibers is too small, the mechanical characteristics of the compression rubber layer are insufficient; and when it is too large, the flexural fatigue strength of the compression rubber layer is decreased (the compression rubber layer becomes rigid, and the bending stress is increased). As a result, a bending loss is increased in the state where a belt winding diameter is small, and fuel economy properties are decreased. Furthermore, when the proportion of short fibers is too large, a dispersability of the short fibers in the rubber composition is decreased to cause poor dispersion, and there is a possibility of cracks being generated in the compression rubber layer in one stage starting from the portions as a starting point. In the present invention, due to the fact that the proportion of short fibers can be suppressed for the above range (in particular, from 15 to 25 parts by mass per 100 parts by mass of the rubber component), due to the flexion of the resin of polyolefin, both the mechanical characteristics and the fuel saving properties of a belt can be obtained.
[0059] For improved adhesion ability to a rubber component, short fibers can be treated by various adhesive treatments, for example, a treatment liquid containing an initial condensate of phenols and formalin (such as a resin prepolymer of novolac or resol type phenol), a treatment liquid containing a rubber component (or a latex), a treatment liquid containing the initial condensate and a rubber component (latex) or a treatment liquid containing a reactive compound ( adhesive compound) such as a silane coupling agent, an epoxy compound (an epoxy resin, etc.) or an isocyanate compound. In the preferred adhesive treatment, the short fibers may be subjected to an adhesive treatment using a treatment liquid containing the initial condensate and a rubber component (latex), particularly at least one resorcin-formalin-latex (RFL) liquid. The adhesive treatment can generally be conducted by dipping the fibers into the RFL liquid, followed by heating and drying, thereby uniformly forming an adhesive layer on the surface of the fibers. Examples of the RFL liquid latex include chloroprene rubber, a styrene-butadiene-vinyl pyridine terpolymer, a hydrogenated nitrile rubber (H-NBR) and nitrile rubber (NBR). These treatment liquids can be used by combining them. For example, short fibers can be subjected to an adhesive treatment, such as a pre-treatment (pre-dip) with a reactive compound (adhesive compound), such as an epoxy compound (such as an epoxy resin) and a compound of isocyanate or a rubber paste treatment (overcoat) after an RFL treatment, and then further treated with an RFL liquid.
[0060] The reinforcement material may contain the conventional reinforcement material, for example, a carbon material such as carbon black, silicon oxide, such as hydrated silica, clay, calcium carbonate, talc and mica, in addition to short fibers. Of these reinforcing materials, carbon black is widely used.
[0061] The proportion of the reinforcement material (the total amount of reinforcement material containing short fibers) may be 90 parts by mass or less, and is, for example, 80 parts by mass or less (for example, 10 to 80 parts by mass), preferably from 20 to 70 parts by mass, and more preferably from around 30 to 60 parts by mass (particularly 40 to 55 parts by mass), per 100 parts by mass of the rubber component. When the proportion of the reinforcing material is too small, there is a possibility that the mechanical characteristics of the compression rubber layer will be diminished. On the other hand, when the proportion of the reinforcing material is too large, the volume proportion of the polyolefin resin is decreased. As a result, it is difficult to project the polyolefin resin onto the surface of the compression rubber layer in a prescribed area, and there is a possibility that a belt's coefficient of friction cannot be reduced. Additives such as a vulcanizing agent
[0062] As needed, the rubber composition may contain a vulcanizing agent or a lattice-forming agent (or a type of lattice-forming agent), a lattice coforming agent, a vulcanization assistant, a lattice accelerator. vulcanization, a vulcanization retardant, a metal oxide (eg, zinc oxide, magnesium oxide, calcium oxide, barium oxide, iron oxide, copper oxide, titanium oxide or aluminum oxide), a softener (for example, oils such as paraffin oil and naphthenic oil), a processing agent or a processing aid (such as stearic acid, stearic acid metal salt, wax or paraffin), an anti-aging agent (such as such as an antioxidant, a thermal anti-aging agent, an anti-flex cracking agent or an antiozonant, etc.), a colorant, a thickener, a plasticizer, a coupling agent (such as a silane coupling agent, etc.) .), a stabilizer (such as an ab ultraviolet absorber or a thermal stabilizer, etc.), a flame retardant, an antistatic agent and the like. Metal oxide can act as a lattice-forming agent.
[0063] As the vulcanizing or lattice-forming agent, conventional components can be used, depending on the type of rubber component, and examples thereof include the above metal oxide (such as magnesium oxide and zinc oxide , etc.), an organic peroxide (such as diacyl peroxide, peroxyester and dialkyl peroxide, etc.) and a sulfur type vulcanizing agent. Examples of the sulfur type vulcanizing agent include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur and sulfur chloride (such as sulfur monochloride or sulfur dichloride, etc.). These lattice-forming agents or vulcanizing agents can be used alone or in a combination of two or more types thereof. When the rubber component is chloroprene rubber, a metal oxide (such as a magnesium oxide and a zinc oxide, etc.) can be used as the vulcanizing agent or the lattice-forming agent. The metal oxide can be used by a combination with another vulcanizing agent (such as a sulfur type vulcanizing agent, etc.), and the metal oxide and/or the sulfur type vulcanizing agent can be used alone or by a combination with a vulcanization accelerator.
[0064] The amount of vulcanizing agent used can be selected from a range from around 1 to 20 parts by mass per 100 parts by mass of rubber component, depending on the type of vulcanizing agent and the component of rubber. For example, the amount of organic peroxide used as the vulcanizing agent may be from 1 to 8 parts by mass, and may be selected from a range of preferably 1.5 to 5 parts by mass, and more preferably, from around 2 to 4.5 parts by mass per 100 parts by mass of rubber component. The amount of metal oxide used can be from 1 to 20 parts by mass, and may be selected from a range preferably from 3 to 17 parts by mass and more preferably from around 5 to 15 parts by mass. mass (eg 7 to 13 parts by mass) per 100 parts by mass of rubber component.
[0065] Examples of the lattice coforming agent (a lattice-forming aid or a covulcanizing agent (coagent)) include conventional lattice-forming aids, e.g., polyfunctional (iso)cyanurate (eg, triallyl isocyanurate (TAIC) or triallyl cyanurate (TAC), etc.), polydiene (eg 1,2-polybutadiene, etc.), an unsaturated carboxylic acid metal salt (eg zinc (meth)acrylate or (meth) )magnesium acrylate, etc.), oxime (e.g. quinone dioxime, etc.), guanidines (e.g., diphenyl guanidine, etc.), polyfunctional (meth)acrylate (e.g., ethylene glycol di(meth)acrylate , butanediol di(meth)acrylate or trimethylolpropane tri(meth)acrylate, etc.), bismaleimides (aliphatic bismaleimide such as N,N'-1,2-ethylene bismaleimide or 1,6'-bismaleimide-(2, 2,4-trimethyl)cyclohexane; and arene bismaleimide or aromatic bismaleimide, such as N,N'-m-phenylene bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 4,4'-diphenyl lmethane bismaleimide, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 4,4'-diphenylether bismaleimide, 4,4'-diphenylsulfone bismaleimide, or 1,3-bis(3-maleimidophenoxy)benzene). These crosshair formation aids can be used alone or in combination of two or more types of them. Of those lattice-forming aids, bismaleimides (arene bismaleimide or aromatic bismaleimide such as N,N'-m-phenylene dimaleimide) are preferred. The degree of lattice formation is increased by the addition of bismaleimides, and adhesive wear can be avoided.
[0066] The proportion of lattice coforming agent (lattice forming aid) can be selected from a range, for example, of around 0.01 to 10 parts by mass, and can be, for example, 0.1 to 5 parts by mass (eg 0.3 to 4 parts by mass) and preferably around 0.5 to 3 parts by mass (eg 0.5 to 2 parts by mass) per 100 parts by mass of the rubber component in terms of solids content.
Examples of the vulcanization accelerator include thiuram accelerators (e.g., tetramethylthiuram-monosulfide (TMTM) tetramethylthiuram-disulfide (TMTD), tetraethylthiuram-disulfide (TETD), tetrabutylthiuram-disulfide (TBTD), dipentamethylenethiuram-tetraTTTT (DPTT) N,N'-dimethyl-N,N'-diphenylthiuram-disulfide), thiazole accelerators (for example, 2-mercaptobenzothiazole, 2-mercaptobenzothiazole zinc salt, 2-mercaptothiazoline, dibenzothiazil-disulfide, or 2-(4' - morphorinodithio)benzothiazole), sulfenamide accelerators (for example N-cyclohexyl-2-benzothiazilsulfenamide (CBS), or N,N'-dicyclohexyl-2-benzothiazilsulfenamide), bismaleimide accelerators (for example N,N'-m - phenylenebismaleimide or N,N'-1,2-ethylenebismaleimide), guanidines (such as diphenylguanidine or di-o-tolylguanidine), urea or thiourea accelerators (for example ethylene thiourea), dithiocarbamates and xanthogenates. These vulcanization accelerators can be used alone or in combination with two or more types of them. Of these vulcanization accelerators, TMTD, DPTT, CBS or similar are widely used.
[0068] The proportion of the vulcanization accelerator may be, for example, from 0.1 to 15 parts by mass, and preferably may be from 0.3 to 10 parts by mass, and more preferably from around 0.5 to 5 parts by mass per 100 parts by mass of the rubber component in terms of solids contents.
[0069] The amount of softener (oils such as naphthenic oil) used can be, for example, from 1 to 30 parts by mass, and may preferably be from around 3 to 20 parts by mass (for example, from 5 to 10 parts by mass) per 100 parts by mass of the total amount of rubber component. The amount of anti-aging agent can be used, for example, from 0.5 to 15 parts by mass, and may be preferably from 1 to 10 parts by mass, and more preferably from around 2.5 to 7 .5 parts by mass (eg 3 to 7 parts by mass) per 100 parts by mass of the total amount of rubber component.
[0070] The structure of the power transmission belt is not particularly limited, and the belt only has to have the compression rubber layer capable of contacting the pulleys. The power transmission belt is provided with a traction member which extends in a direction along the length of the belt, an adhesion rubber layer in contact with at least a part of the traction member, a compression rubber layer formed on one surface of the adhesive layer, and a traction rubber layer formed on the other surface of the adhesion rubber layer.
[0071] Figure 1 is a schematic cross-sectional view illustrating an example of a power transmission belt. In this example, a traction member 2 is embedded in an adhesion rubber layer 1, a compression rubber layer 3 is laminated to a surface of the adhesion rubber layer 1, and a traction rubber layer 4 is laminated to the another surface of the adhesion rubber layer 1. The traction member 2 is integrally embedded in the form of being sandwiched between a pair of adhesion rubber layers. Furthermore, a reinforcing fabric 5 is laminated to the compression rubber layer 3, and tooth portions 6 are formed by a mold with teeth. A laminate of the compression rubber layer 3 and the reinforcing fabric 5 is integrally formed by vulcanizing a laminate of a reinforcing fabric and a compression rubber layer sheet (a vulcanized rubber sheet).
[0072] An example of a serrated V-belt is illustrated in the example above, but the structure is not limited to the structure above, and can be applied to various belts having the compression rubber layer (for example, a rough edge brace or a V-ribbed strap). Rubber traction layer
[0073] The traction rubber layer may be formed of a vulcanized rubber composition containing the rubber component, as exemplified in the compression rubber layer, and may contain a reinforcing material and a polyolefin resin, similarly to compression rubber layer. Furthermore, the traction rubber layer may be a layer formed from the same vulcanized rubber composition as the compression rubber layer. Adhesion rubber layer
[0074] Similar to the vulcanized rubber composition of the compression rubber layer, the vulcanized rubber composition for forming the adhesion rubber layer may contain a rubber component (such as a chloroprene rubber, etc.), a vulcanizing agent or a lattice-forming agent (e.g. a metal oxide such as magnesium oxide or zinc oxide, or a sulfur type vulcanizing agent such as sulfur, etc.), a curing agent lattice coforming or a lattice-forming aid (for example, a maleimide lattice-forming agent such as N,N'-m-phenylene dimaleimide, etc.), a vulcanization accelerator (such as TMTD, DPTT and CBS, etc.), an improver (such as carbon black and silica, etc.), a processing agent or a processing aid (such as stearic acid, stearic acid metal salt, wax and paraffin, etc.), an anti-aging agent, a tack-improving agent (such as an anti-aging agent; resorcin-formaldehyde condensate and an amino resin (a condensate of a cyclic compound containing nitrogen and formaldehyde, for example, a melamine resin such as hexamethylolmelamine or hexaalkoxymethylmelamine (such as hexamethoxymethylmelamine and hexabutoxymethylmelamine, etc.), such a urea resin such as methylurea, and a benzoguanamine resin (such as a methylolbenzoguanamine resin, etc.) those cocondensates (such as a resorcine-melamine-formaldehyde cocondensate, etc.), a filler (such as clay, calcium carbonate, talc and fuel-air mixture, etc.), a colorant, a thickener, a plasticizer, a coupling agent (such as a silane coupling agent, etc.), a stabilizer (such as an ultraviolet absorber or a thermal stabilizer , etc.), a flame retardant, an antistatic agent and the like. In the tack-improving agent, the resorcin-formaldehyde and amino resin cocondensate can be an initial condensate (prepolymer) of resorcin and/or a cyclic nitrogen-containing compound such as melamine and formaldehyde.
[0075] In this rubber composition, a rubber of the same series (such as a diene rubber) or of the same type (such as a chloroprene rubber) as the rubber component of the vulcanized rubber composition of the compression rubber layer often is used as the rubber component. Furthermore, the amounts of the vulcanizing agent or lattice forming agent, the lattice coforming agent or lattice aid, the vulcanization accelerator, the improver, the softener, and the anti-aging agent used can be selected from of the same bands as in the rubber composition of the compression rubber layer, respectively. Furthermore, in the vulcanized rubber composition of the adhesion rubber layer, the amount of the processing agent or processing aid (such as stearic acid) can be used, for example, from 0.1 to 10 parts by mass, and may preferably be from 0.5 to 5 parts by mass, and more preferably from around 1 to 3 parts by mass per 100 parts by mass of the rubber component. Furthermore, the amount of the tack-improving agent (such as a cocondensate of resorcin-formaldehyde and hexamethoxymethylmelamine) may be, for example, from 0.1 to 20 parts by mass, and may preferably be from 1 to 10 parts by mass, and more preferably from around 2 to 8 parts by mass per 100 parts by mass of the rubber component. Traction member
[0076] The traction member is arranged extending in one direction along the length of a strap, and is generally arranged side by side in prescribed steps parallel to the direction along the length of the strap. It is sufficient for the traction member if only at least a part of it is in contact with the adhesion rubber layer, and it can be any of the modalities where the traction member is embedded in the adhesion rubber layer, the mode wherein the traction member is embedded between the adhesion rubber layer and the traction rubber layer, and the embodiment wherein the traction member is embedded between the adhesion rubber layer and the compression rubber layer. Of these embodiments, the embodiment in which the traction member is embedded in the adhesion rubber layer is preferred from a standpoint that durability can be improved.
[0077] Examples of the fiber constituting the pulling member may include the same fibers as the short fibers. Of the fibers, synthetic fibers, such as polyester fibers (polyalkylene arylate fibers) containing C2-C4 alkylene arylate, such as ethylene terephthalate and ethylene-2,6-naphthalate as a main constituent unit, and aramid fibers, inorganic fibers such as carbon fibers and the like are widely used from a high modulus standpoint, and polyester fibers (polyethylene terephthalate fibers and ethylene naphthalate fiber) and polyamide fibers are preferred. The fiber can be a multi-filament yarn. The fineness of the multifilament yarn can be, for example, from around 2,000 to 10,000 denier (particularly 4,000 to 8,000 denier). The multi-filament yarn may contain, for example, from 100 to 5,000, preferably from 500 to 400, and more preferably from 1,000 to 3,000 of multi-filament yarns.
[0078] A braided strand (eg, a stacked strand, a one-piece braided strand or a Lang braided strand) using a multi-filament yarn can generally be used as the pulling member. The average strand diameter of the pulling member (fiber braided strand diameter) may be, for example, 0.5 to 3 mm, and may preferably be 0.6 to 2 mm, and more preferably around 0.7 to 1.5 mm.
[0079] In order to improve the adhesiveness to a rubber component, the cord can be subjected to an adhesive treatment (or a surface treatment) in the same method as in short fibers. It is preferred that the cord be subjected to an adhesive treatment with at least one liquid RFL, similar to short fibers. Power Transmission Efficiency
[0080] When the power transmission belt provided with the compression rubber layer is used, the power transmission efficiency can be greatly improved. Power transmission efficiency is an index that a belt transmits rotating torque from drive pulleys to driven pulleys, and means that the higher the power transmission efficiency, the lower the loss of belt transmission, and that Thus, the fuel economy properties are excellent. In a biaxial layout, in which a belt 11 is hung on two pulleys of a drive pulley (Dr.) 12 and a driven pulley (Dn.) 13, as illustrated in Figure 2, power transmission efficiency can be achieved as follows.
[0081] When the number of revolutions of the drive pulley is pi and a pulley radius is ri, a rotating torque Ti of the drive pulley can be represented by pixTexri. Te is an effective pull obtained by subtracting the loose side pull (traction on one side towards which a belt moves a driven pulley) from the tight side pull (traction on one side for which a belt moves towards the pulley drive). Similarly, when the number of revolutions of the driven pulley is p2 and a pulley radius is r2, a rotating torque T2 of the driven pulley can be represented by p2xTexr2. The power transmission efficiency T2/Ti is calculated by dividing the rotary torque T2 of the driven pulley by the rotary torque Ti of the drive pulley, and can be represented by the following formula.T2/Ti=(p2xTexr2)/(pixTexri)= (p2xr2)/(pixri)
[0082] Practically, the power transmission efficiency does not become the value no less than i, but the transmission loss of a belt is small as the value approaches i, showing excellent consumption saving properties of fuel.
[0083] A method for producing a strap is not particularly limited, and conventional methods can be used. For example, the belt illustrated in Figure 1 can be formed by forming a laminate of unvulcanized rubber layers having the above embodiment having a pull member embedded therein by a mold, by vulcanizing the mold laminate into a belt sleeve and then by cutting the vulcanized strap sleeve to a prescribed size. Examples
[0084] The present invention is described below in greater detail based on examples, but it should be understood that the present invention is not limited by these examples. In the following examples, the raw materials used in the examples are shown below. Raw MaterialShort Aramid Fiber
[0085] A short fiber having a solid content adhesion ratio of 6% by mass obtained by subjecting a short aramid fiber (average fiber length: 3 mm, "CONEX Short Fiber" manufactured by Teijin Technoproducts) to an adhesive treatment with an RFL liquid (containing resorcin, formaldehyde and vinylpyridine-styrene-butadiene rubber latex as a latex). The used RFL liquid contained resorcin: 2.6 parts by mass; 37% formalin: 1.4 parts by mass, vinylpyridine-styrene-butadiene copolymer latex (manufactured by Zeon Corporation): 17.2 parts by mass, and water: 78.8 parts by mass. Polyolefin
[0086] The polyolefins used are shown in Table 1 below:
[0087] Table 1
Other additives
[0088] Ester ether oil: “RS700” manufactured by ADEKA Carbon black: “SEAST 3” manufactured by Tokai Carbon Co., Ltd.Anti-aging agent: “NONFLEX OD3” manufactured by Seiko Chemical Co., Ltd.Silica: NIPSIL VN-3” manufactured by Tosoh Silica Corporation Vulcanization Accelerator: Detetramethylthiuram Disulfide (TMTD) traction member
[0089] A fiber obtained through an adhesive treatment of strands having a total denier of 6,000 denier obtained by stacking 1,000 denier PET fibers under a 2x3 twist structure at a final twist coefficient of 3.0 and a first torsional coefficient of 3.0. Examples 1 to 9 and Comparative Examples 1 to 2 Formation of rubber layer
[0090] Each of the rubber compositions in Table 2 (compression rubber layer and traction rubber layer) and Table 3 (adhesion rubber layer) were kneaded using a conventional method, such as a mixer. Banbury, and the respective crumpled rubbers were passed through calender rollers for the preparation of rolled rubber sheets (compression rubber layer sheet, tensile rubber layer sheet and adhesion rubber layer sheet).
[0091] Table 2

[0092] Table 3
Strap Production
[0093] A laminate of reinforcing fabric and compression rubber layer sheet (unvulcanized rubber) was arranged in a mold with flat teeth, in which tooth portions and groove portions are alternately provided, in the fabric state of facing down, and pressurized in a press at 75°C for the preparation of a tooth pad having etched tooth portions (which is not fully vulcanized and is in a semi-vulcanized state). Then both ends of the toothed pad were cut vertically from the top of a tooth mountain portion.
[0094] A cylindrical mold was covered with an inner mother mold having tooth portions and groove portions alternately provided, the tooth pad was rolled up by mating with the tooth and groove portions for joining at the top of the tooth mountain portion , a first adhesion rubber layer sheet (unvulcanized rubber) was laminated to the rolled tooth pad, the pulling member was spirally spun, and a second adhesion rubber layer sheet (same as the first sheet of rubber). adhesion rubber layer) and a sheet of tensile rubber layer (unvulcanized rubber) were subsequently rolled therein for the preparation of a molded article. After that, the mold was covered with a jacket and placed in a vulcanization drum, and a vulcanization was carried out at a temperature of 160 °C for 20 minutes, to obtain a belt sleeve. This glove was cut into a V-shape by using a cutter to prepare a belt having the structure shown in Figure 1, that is, a serrated V-belt with rough edge (size: top width: 22.0 mm, thickness: 11.0 mm and outer length: 800 mm) which is a variable speed belt having teeth on an inner circumferential side of the belt. Measurement of vulcanized rubber properties(1) Hardness
[0095] The compression rubber layer sheet was press vulcanized at a temperature of 160 °C for 20 minutes, for the preparation of a vulcanized rubber sheet (length: 100 mm, width: 100 mm and thickness: 2 mm ). According to JIS K6253 (2012), a laminate obtained by stacking three sheets of vulcanized rubber was used as a sample, and the hardness was measured using a Type A Durometer hardness tester.(2) Abrasion amount
[0096] A cylindrical specimen having a diameter of 16.2 + 0.2 mm and a thickness from 6 to 8 mm was prepared by cutting by using a hollow drill having an internal diameter of 16.2 + 0.05 mm from a vulcanized rubber sheet (50 mm x 50 mm x 8 mm thick) prepared by press vulcanizing the compression rubber layer sheet at a temperature of 160 °C for 20 minutes. The amount of abrasion of the vulcanized rubber was measured by using a rotating cylindrical drum apparatus (DIN abrasion tester) having a polishing fabric wound on it, in accordance with JIS K6264 (2005). (3) Compressive stress
[0097] The compression rubber layer sheet was press vulcanized at a temperature of 160 °C for 20 minutes for the preparation of a vulcanized rubber molded article (length: 25 mm, width: 25 mm and thickness: 12, 5 mm). The short fibers were made to orient themselves in a vertical direction (thickness direction) with a compression surface. The vulcanized rubber molded article was sandwiched above and below with two metal compression plates (wherein an initial position was defined as the position of the upper compression plate in the intercalated state where the vulcanized molded article is not pressed with the plates compression), the upper compression plate was pressed into the vulcanized rubber molded article at a rate of 10 mm/min (press surface 25 mm x 25 mm) to distort the vulcanized rubber molded article 20%, this state was held for 1 second, and the compression plate was returned higher than the initial position (preliminary compression). After 3 times repetition of preliminary compression, from a stress-strain curve measured in a fourth compression test (conditions were the same as in preliminary compression), a stress when a deformation in one thickness direction of the molded article of vulcanized rubber reached 10% was measured as the compressive stress. To minimize a variation in the measurement data, preliminary compression was conducted three times.(4) Bending stress
[0098] The compression rubber layer sheet was vulcanized with pressing at a temperature of 160 °C for 20 minutes for the preparation of a molded article of vulcanized rubber (length: 60 mm, width: 25 mm and thickness 6.5 mm). The short fibers were made to orient in a direction parallel to the width of the vulcanized rubber molded article. As illustrated in Figure 3, the vulcanized rubber molded article 21 was placed and supported on a pair of rotating rollers (6mm diameter) 22a and 22b in the 20mm range, and a metal pressure member 23 was placed on a central portion of an upper surface of the molded rubber article vulcanized in a width direction (short fiber orientation direction). The tip of the pressing member 23 has a semi-circular shape that has a diameter of 10 mm, and the vulcanized rubber molded article 21 can be pressed gently by the tip. Furthermore, during pressing, a frictional force acts between the lower surface of the vulcanized rubber molded article 21 and the rollers 22a and 22b with a compressive deformation of the vulcanized rubber molded article 21, but the influence by friction is minimized by the rollers 22a and 22b are rotated. The state in which the tip of the pressure member 23 contacts the upper surface of the vulcanized rubber molded article 21, but does not press down, was defined as "0", and the tension when the pressure member 23 presses down on the upper surface of the vulcanized rubber molded article 21 at a rate of 100 mm/min from the state and a deformation of the vulcanized rubber molded article 21 in a thickness direction reached 10% was measured as a bending stress. Shape and Area of Polyolefin in Belt Compression Rubber Layer
[0099] Regardless of the polyolefin in the compression rubber layer of a belt, the belt was cut along a wide direction and observed with a scanning electron microscope (SEM), and based on the image obtained, an average diameter (long diameter) of a major axis and an average diameter (short diameter) of a polyolefin minor axis (polyolefin particles) were measured using a Soft measurement (“analySIS”, manufactured by Soft Imaging System). Furthermore, with reference to the frictional power transmission surface (outer surface of compression rubber layer) on the circumference of belt 1, the area occupied by the polyolefin particles (polyolefin phase) on the frictional power transmission surface was calculated in three arbitrary portions (area 1.2 mm2 (1.0 mm x 1.2 mm)) using the Soft measurement based on the image of a scanning electron microscope. Belt properties measurement(1) Friction coefficient measurement
[0100] As illustrated in Figure 4, one end of the cut strap 31 was attached to a load cell 32, a load 33 of 3 kgf (29.42 N) was placed on the other end, and strap 31 was wound onto a pulley 34 with a belt winding angle with pulley 34 being 45°. The strap 31 on the cell side of 32 was pulled at a rate of 30 mm/min for about 15 seconds, and an average friction coefficient of a frictional power transmission surface was measured. During measurement, pulley 34 was fixed so that it would not rotate.(2) High load stroke test
[0101] In this stroke test, the power transmission efficiency of a belt when traveling in a state where the belt was largely flexed (in the state of winding on a small pulley) was evaluated.
[0102] The high load stroke test was conducted, as illustrated in figure 5, by using a biaxial stroke testing machine containing a drive pulley (Dr.) 42 having a diameter of 50 mm and a driven pulley ( Dn.) 43 having a diameter of 125 mm. A rough edge toothed V-belt 41 was hung over each of the pulleys 42 and 43, a load of 3 Nm was applied to the driven pulley 43, and the strap 41 was traveling in an atmosphere at room temperature at the rate of revolution of the pulley. drive 42 at 3,000 rpm. The number of revolutions of the driven pulley 43 was read by a detector immediately after the stroke, and a power transmission efficiency was obtained by the calculation formula described above. In Table 4, the power transmission efficiency of Comparative Example 1 is indicated as "1", and the power transmission efficiency of each example and the comparative example is shown by a relative value. It was judged that when the value is greater than 1, the performance of the belt 41, i.e. the fuel saving properties, is high.(3) High Speed Stroke Test
[0103] In this stroke test, the power transmission efficiency of a belt when traveling in the state where a belt is slid out of a pulley radius direction on a pulley was evaluated. Particularly, when the rate of revolution of a driven pulley is increased, a strong centrifugal force acts on a belt. Furthermore, the belt traction acts weakly in a position on a loose side of a drive pulley (see figure 6), and the belt tries to come out in a pulley radius direction in this position by composite action. with centrifugal force. When the output is not conducted smoothly, that is, a friction force acts strongly between the frictional power transmission surface of the belt and the pulley, a transmission loss is generated by the friction force, leading to a decrease in transmission efficiency of power.
[0104] The high speed stroke test was conducted, as illustrated in figure 6, by using a biaxial stroke testing machine containing a drive pulley (Dr.) 52 having a diameter of 95 mm and a driven pulley ( Dn.) 53 having a diameter of 85 mm. A rough edge toothed V-belt 51 was hung over each of the pulleys 52 and 53, a load of 3 Nm was applied to the driven pulley 53, and the strap 51 was traveling in an atmosphere at room temperature at the rate of revolution of the pulley. drive 52 at 5,000 rpm. The number of revolutions of the driven pulley 53 was read by a detector immediately after the stroke, and a power transmission efficiency was obtained by the calculation formula described above. In Table 4, the power transmission efficiency of Comparative Example 1 is indicated as "1", and the power transmission efficiency of each example and the comparative example is shown by a relative value. It was judged that, when the value is greater than 1, the performance of the Belt 51, ie the fuel economy properties, is high.(4) Durability Stroke Test
[0105] The durability stroke test was conducted, as shown in figure 7, by the use of a biaxial stroke testing machine containing a drive pulley (Dr.) 62 having a diameter of 50 mm and a driven pulley (Dn .) 63 having a diameter of 125 mm. A raw edge serrated V-belt 61 was hung over each of pulleys 62 and 63, a load of 10 Nm was applied to the driven pulley 63, and the strap 61 was traveling for a maximum of 60 hours at an ambient temperature of 80° C at the 5,000 rpm drive pulley 62 revolution rate. It was judged that when strap 61 traveled for 60 hours, there was no durability issue. Furthermore, a lateral surface of the belt (surface in contact with a pulley) after the stroke was observed with a microscope, and the presence or absence of peeling of the traction member was examined. With respect to the peeled portion, the peeling depth was measured with a microscope. Furthermore, a lateral surface of the compression rubber (surface in contact with a pulley) after a stroke was visually observed, and the presence or absence of cracks was examined. Furthermore, with reference to the belt after the high load durability course, the coefficient of friction and the power transmission efficiency were measured.
[0106] The properties of a vulcanized rubber and the properties of a belt are shown in Table 4.
[0107] Table 4

[0108] As is evident from Table 4, in a comparison of the examples with the comparative examples, it can be seen that, by the addition of polyolefin, the compressive strength is improved (increased) and the peeling and cracking of the member of traction are improved. This can make it presumable that polyolefin played a role as a reinforcing material, a volume fraction of short fibers was decreased, and, as a result, durability was improved. It can be seen, further, that by adding polyolefin, a change in the coefficient of friction between durability before and durability after is small, and power transmission efficiency is improved. This can lead to the assumption that short fibers are abraded by friction, a reduction in a coefficient of friction is attempted by the polyolefin projecting onto the belt surface. Furthermore, comparing polyethylene with polypropylene, the addition of polyethylene showed slightly excellent durability.
[0109] With reference to the examples, as a result of observing the shape of the polyolefin in the compression rubber layer by SEM, everything showed a long slender shape similar to the potato shape, and they were dispersed in the state of a geometric axis direction. larger to have been oriented in a strap-width direction. An SEM (image) photograph of the belt cross section (cross-sectional cut in a belt width direction) taken in Example 3 is shown in Figure 8. Of the particles (dispersed phase) dispersed in the drawing, the large particles are of polyethylene, and the small particles are short aramid fibers.
[0110] Although the present invention has been described in detail with reference to specific embodiments, it is clear to one skilled in the art that various modifications or changes can be made without departing from the spirit and scope of the present invention.
[0111] This application is based on Japanese Patent Application No. 2013-073402, filed March 29, 2013 and Japanese Patent Application No. 2014-043510, filed March 6, 2014, the contents of which are incorporated herein as reference. Industrial Applicability
[0112] The power transmission belt of the present invention can be used as various belts in which a transmission loss is required, and is preferably a power transmission belt with friction. Examples of frictional power transmission belt include a rough edged belt having a V-shaped cross section, a rough edge toothed V belt having teeth provided on an inner circumferential side or on both an inner circumferential side and a outer circumferential side of a rough edge brace, and a ribbed V- brace. Particularly, it is preferred to apply a sling (a variable speed sling) used in a transmission, in which a vehicle shift ratio is continuously changed, during the course of the sling, for example a rough edge toothed sling and a sling double-toothed V-shaped gross edge on motorcycles, all-terrain vehicles (four-wheel buggy), snowmobiles and the like. Description of Reference Numbers and Signs
[0113] 1: adhesion rubber layer 2: tensile member 3: compression rubber layer4: tensile rubber layer

权利要求:
Claims (11)
[0001]
1. A power transmission belt comprising: a traction member (2) extending in a direction along the length of the strap; an adhesion rubber layer (1) in contact with at least a portion of the traction member ( 2); a compression rubber layer (3) formed on a surface of the adhesion rubber layer (1); and a traction rubber layer (4) formed on the other surface of the adhesion rubber layer (1), the belt being characterized in that the compression rubber layer (3) is formed of a vulcanized rubber composition containing a rubber component, a polyolefin resin and a reinforcing material, the rubber component containing chloroprene rubber, and the reinforcing material containing an average fiber length of 1 to 20 mm.
[0002]
2. Power transmission belt, according to claim 1, characterized in that the reinforcing material has a proportion of 80 parts by mass or less per 100 parts by mass of the rubber component.
[0003]
3. Power transmission belt, according to claim 1 or 2, characterized in that the polyolefin resin has a ratio of 5 to 40 parts by mass per 100 parts by mass of the rubber component.
[0004]
4. Power transmission belt, according to any one of claims 1 to 3, characterized in that the polyolefin resin has a proportion of 15 to 50 parts by mass per 100 parts by mass of the reinforcement material.
[0005]
5. Power transmission belt, according to any one of claims 1 to 4, characterized in that the fiber with an average length of 1 to 20 mm has a proportion of 15 to 25 parts by mass per 100 parts by mass of the component of rubber.
[0006]
6. A power transmission belt according to any one of claims 1 to 5, characterized in that the polyolefin resin has an average molecular weight of 200,000 to 6,000,000 in a method measured in accordance with ASTM D 4020.
[0007]
7. Power transmission belt, according to any one of claims 1 to 6, characterized in that a polyolefin resin raw material has an average particle diameter of 25 to 200 μm.
[0008]
8. Power transmission belt according to any one of claims 1 to 7, characterized in that the polyolefin resin in the compression rubber layer (3) has a long slender shape having an aspect ratio of 1.6 through 10, a major axis direction can be oriented parallel to a strap width direction, and a minor axis direction can be oriented parallel to the strap length direction.
[0009]
9. Power transmission belt, according to any one of claims 1 to 8, characterized in that the reinforcement material contains an aramid fiber with an average length of 1 to 20 mm and a carbon black.
[0010]
10. Power transmission belt according to any one of claims 1 to 9, characterized in that the polyolefin resin is exposed on a surface of the compression rubber layer (3).
[0011]
11. Power transmission belt, according to any one of claims 1 to 10, characterized in that the polyolefin has an occupation area of 0.2 to 30% on a surface of the compression rubber layer (3).

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同族专利:

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US20160298725A1|2016-10-13|

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法律状态:
2018-11-13| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|

2019-09-03| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|

2020-08-11| B06A| Patent application procedure suspended [chapter 6.1 patent gazette]|

2021-01-05| B06A| Patent application procedure suspended [chapter 6.1 patent gazette]|

2021-05-11| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|

2021-06-01| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 27/03/2014, OBSERVADAS AS CONDICOES LEGAIS. |

优先权:

申请号 | 申请日 | 专利标题

JP2013-073402|2013-03-29|

JP2013073402|2013-03-29|

JP2014-043510|2014-03-06|

JP2014043510A|JP6055430B2|2013-03-29|2014-03-06|Transmission belt|

PCT/JP2014/059049|WO2014157592A1|2013-03-29|2014-03-27|Transmission belt|

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