[0001]The present invention relates to a V-ribbed belt used in the automotive engine accessory drive, particularly, ground by reduces the grinding amount in a method of forming a rib portion, and relates appearance and excellent V-ribbed belt and a manufacturing method thereof durability .
Background technique
[0002]
　Among the rubber industry, highly functional, higher performance is desired, particularly in automotive parts. One of the rubber products used in such automotive components, there is a V-ribbed belt which is provided along the ribs in the longitudinal direction of the belt, the V-ribbed belt, for example, the accessory drive such as an air compressor and an alternator of a motor vehicle It is widely used in power transmission.
[0003]
　As a method for producing the V-ribbed belt, a manufacturing method of forming the rib portion of the reversed-trapezoid shaped cross-section (the compression rubber layer) is known by grinding. Specifically, in the process of manufacturing the V-ribbed belt, it is first formed a cylindrical mold of the outer circumferential surface to the respective molded part (outer skin, the unvulcanized rubber sheet, core wire, etc.) of the belt sleeve formed by laminating by winding a. Usually, the belt sleeve (compression rubber layer forming the ribs) grinding surface is on the outer circumferential side to form a sleeve so that the belt back is the inner circumferential side. Next, place in a state covered with the vulcanized jacket on the outer peripheral side of the belt sleeve in the vulcanizer perform vulcanization. In the vulcanization of the belt sleeve, vulcanizing and vulcanized in a state of being contact with the belt sleeve outer peripheral surface and vulcanized jacket circumferential surface (demolding) removing the vulcanized jacket after vulcanization. Further, the vent (air vent) so as not air (bubbles) accumulate in the belt sleeve during the vulcanization is needed. This and releasing property, in order to ensure the ventilation (air vent), the vulcanization by winding a partial thick nonwoven fabric sleeve outer circumferential surface, after the release, non-woven fabric be ground with grinding part of the compressed rubber removal to method (a method of grinding the entire rib portion) is adopted.
[0004]
　Recently, reduction and the grinding amount from the viewpoint of cost reduction (waste rubber amount) Efforts material cost reduction has been made due to a reduction in the belt thickness. The reduction of the amount of grinding (waste rubber weight), instead of grinding the entire rib, is method of grinding the distal end surface of the rib portion (inverted trapezoidal bottom shape) only a V-groove without grinding (side only) It has been studied, since the vulcanized belt sleeve outer circumferential surface in this method the ribs tip surface directly, the use of non-woven fabric on the outer peripheral surface, the nonwoven remains on the front end surface of the rib portion (rib tip surface).
[0005]
　The V-ribbed belt having a non-woven fabric in the rib tip surface, for example, Patent Document 1, without using the short fiber-containing rubber, in order to suppress the wear of the abnormal noise and the belt surface generated between the pulley to, it has been proposed to configure a structure of alternately laminated rubber layer and the nonwoven fabric layer ribbed rubber layer in the belt thickness direction, V-ribbed belt having a non-woven fabric layer is disclosed in the rib tip surface of the rib rubber layer.
[0006]
　However, this V-ribbed belt, because the ribbed rubber layer underlying the plurality of nonwoven layers, the belt becomes rigid, the belt travel, decreases the flexibility of the belt (hinders the bending nonwoven fabric taut), durability sex decreases (cracks are liable to enter). Further, since the rib rubber layer is divided by a nonwoven layer, also tends to occur delamination. Furthermore, in this document, in order of noise suppression and wear suppression of the friction belt surface generated between the pulleys, the nonwoven layer instead of the short fibers to be contained in the rubber is introduced, problems in the grinding method is Not listed. This document, such basis weight, but not more nonwoven layers are described, in general, the V-ribbed belt having a non-woven fabric in the rib tip surface, aesthetic visual quality of the nonwoven fabric surface is reduced.
[0007]
　On the other hand, when prepared without the use of non-woven fabric, releasability and breathability (air vent) addition is insufficient, the surface properties of the vulcanized jacket is transferred to the sleeve surface (rib tip surface), for example, surface is scratched in the case of vulcanization jacket, scratches appearance is transferred drops.
[0008]
　Further, Patent Document 2, V-ribbed belt having a thermoplastic resin layer (film-like layer not fibrous) is disclosed in the rib tip surface. This document, after bonding the thermoplastic resin layer and ribs are described as being scraped V-belt shape by cutting the belt.
[0009]
　However, even in this V-ribbed belt, on top of insufficient ventilation (air vent), (become in the way of bending the thermoplastic resin layer is taut) flexibility of the belt is reduced, the durability is lowered (cracks easily enter).
CITATION
Patent Literature
[0010]
Patent Document 1: Japanese Patent 2005-69358 JP
Patent Document 2: Japanese Kohyo 2005-533983 JP
Summary of the Invention
Problems that the Invention is to Solve
[0011]
　Accordingly, an object of the present invention is to provide a small amount of grinding by (amount of waste rubber) can be formed by grinding the rib portion, and the V-ribbed belt and a manufacturing method thereof a vulcanization process can proceed smoothly.
[0012]
　Another object of the present invention is excellent in appearance, and to provide a V-ribbed belt and a manufacturing method thereof durability can be improved, such as crack resistance and heat resistance.
[0013]
　Still another object of the present invention, it is unnecessary to adhesion treatment of the fiber aggregate, and also contain fibers, is to provide a V-ribbed belt and a manufacturing method thereof capable of improving the workability winding.
Means for Solving the Problems
[0014]
　The present inventors have made intensive studies to achieve the above objects, the side is ground surface in contact with the pulley, and bottom of the bottom portion of the compression rubber layer of the V-ribbed belt which is a non ground surface not in contact with the pulley on the surface, vulcanization of the a fiber aggregate of a particular basis weight, including a heat-resistant fiber that does not melt at the vulcanization temperature of the rubber composition constituting the compression rubber layer, the rubber composition impregnated between fibers of the fiber assembly by forming a composite layer containing an object, a small amount of grinding can be formed rib portions by grinding (amount of waste rubber), and found that the vulcanization step can proceed smoothly, thereby completing the present invention.
[0015]
　Ie, V-ribbed belt of the present invention is provided with a compression rubber layer comprising a vulcanizate and core and an extended layer of the rubber composition, the side of the compression rubber layer is ground surface in contact with the pulley, and the bottom of the compression rubber layer is a V-ribbed belt is unground surface not in contact with the pulley, the surface of the bottom portion, comprises a heat-resistant fiber that does not melt at the vulcanization temperature of the rubber composition and basis weight 25g / m 2 has a fiber aggregate less, a composite layer containing an vulcanizates of this fiber assembly was impregnated between fibers (infiltrated or present) the rubber composition. The heat-resistant fibers may comprise polyester fibers. The fiber assembly may have a non-woven fibrous structure. Basis weight of the fiber aggregate 8 ~ 20 g / m 2 may be about. The compression rubber layer may form a continuous phase in vulcanized rubber composition. The average fiber diameter of the heat-resistant fiber may be about 1 ~ 50 [mu] m. The heat-resistant fiber may comprise long fibers. In the composite layer, heat-resistant fibers are preferably not fused. The compression rubber layer may contain short fibers. In the fiber assembly having a nonwoven fiber structure (nonwoven fibrous structure or non-woven fabric), heat-resistant fibers, and oriented in a predetermined direction, the longitudinal direction may be parallel to the longitudinal direction of the belt. The compression rubber layer may have a rib portion, the average thickness of the rib portion may be not more than 54% relative to the average thickness of the entire V-ribbed belt.
[0016]
　The present invention is strained layer mounting step of mounting the stretching layer member for forming a stretching layer on a cylindrical drum, core spinning process further winding the core wire as a core, to further form a compression rubber layer step with compression rubber layer winding of winding the unvulcanized rubber sheet, obtained on the unvulcanized rubber sheet wound further step with fiber aggregate winding that winds the fiber aggregate comprising a heat-resistant fiber, by the steps belt molding body (unvulcanized belt sleeve) vulcanization process to obtain a vulcanized by vulcanizing the belt sleeve, the fiber assembly side of the vulcanized belt sleeve, grinding step of forming only the side of the compression rubber layer in grinding method of manufacturing the V-ribbed belt including also included. The average thickness of the fiber aggregate may be about 0.03 ~ 0.15 mm.
Effect of the invention
[0017]
　In the present invention, the side is ground surface in contact with the pulley, and the surface of the bottom of the bottom compression rubber layer of the V-ribbed belt which is a non ground surface not in contact with the pulley, the rubber composition constituting the compression rubber layer since the composite layer containing an vulcanizates vulcanization temperatures and a fiber aggregate of a particular basis weight including heat resistant fibers which do not melt in the rubber composition impregnated between fibers of the fiber aggregate are stacked, grinding the bottom of the compression rubber layer is unnecessary, it is possible to form the rib portion by grinding with a small amount of grinding (waste rubber amount). Further, since the fiber aggregate such as a nonwoven fabric can be secured releasability and breathability in the vulcanization step, the air vent and the vulcanization can proceed smoothly release from vulcanized jacket. Therefore, it can also be suppressed transcription, such as scratches and stains of vulcanized jacket. Further, by selecting a particular fiber aggregate having a nonwoven fibrous structure, the moderately rubber composition between the fibers are mixed with embedded, fluff can be suppressed fibers can improve the appearance. Also, since the fibers only at the bottom surface of the compression rubber layer is integral with the vulcanized rubber composition forming the compression rubber layer, excellent in flex resistance of the belt, it is possible to improve the durability such as crack resistance both heat resistance can be maintained. Furthermore, in order to integrate and the fiber assembly and the compression rubber layer by vulcanization, adhesion treatment of the fiber aggregate is not required. Further, with the parallel to the longitudinal direction of the longitudinal belt of heat resistant fibers, also comprise fibers, it is possible to suppress elongation and breakage when pulled in the winding direction (circumferential direction), workability winding the belt It can be improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018]
[1] Figure 1 is a schematic sectional view showing an example of a V-ribbed belt of the present invention.
FIG. 2 is a tester layout using the flex fatigue resistance (crack resistance) test in Examples.
FIG. 3 is a surface electron microscope photograph of a composite layer of a V-ribbed belt obtained in Example 1.
[4] FIG. 4 is a photograph of the rib portion of the V-ribbed belt obtained in Example 1.
FIG. 5 is a photograph of the rib portion of the V-ribbed belt obtained in Reference Example 1.
DESCRIPTION OF THE INVENTION
[0019]
　V-ribbed belt of the present invention, cross-section by grinding are formed in inverted trapezoidal shape substantially, and comprises a compression rubber layer comprising a vulcanizate of a rubber composition, grinding the side of the compression rubber layer is in contact with the pulley a surface, and a bottom portion of the compression rubber layer is a non-ground surface which is not in contact with the pulley.
[0020]
　Form of V-ribbed belt, as long as it has such a compression rubber layer is not particularly limited, for example, the form shown in Figure 1 is illustrated. Figure 1 is a schematic sectional view showing an example of a V-ribbed belt of the present invention. This embodiment is in order from the belt top surface (back surface) on the belt bottom surface (inner circumferential surface), the outer skin (woven, knitted, such as a nonwoven fabric) stretched layer 1 configured by the belt longitudinal direction the core body (core wire) 2 adhesive rubber layer 3 in which are embedded, compression rubber layer 4 has the form of laminated composite layer 5. Wherein the compression rubber layer 4 is formed with a plurality of V-shaped grooves extending in belt longitudinal direction, it tapers trapezoidal toward the tip of the V-shaped cross section [inverted trapezoid (ribs between the grooves ) a plurality of ribs (four in the example shown in FIG. 1) has been formed, the two inclined surfaces of the rib portion (surface) forms a friction transmission surface, transmitting power in contact with the pulley (friction transmission) to. In particular, the present invention, the side surface of the rib portion (inclined surface) is ground surface 4a, a composite layer 5 of unground surface to the bottom surface of the rib portion.
[0021]
　V-ribbed belt of the present invention is not limited to this embodiment, it suffices that with such a compression rubber layer, for example, may be a strained layer was formed of a rubber composition, stretching layer without providing an adhesive rubber layer it may be embedded core (core wire) between the compression rubber layer. Furthermore, provided the adhesive rubber layer in one of the compression rubber layer or stretch layer, core between (core wire) the adhesive rubber layer (compression rubber layer side) stretching layer, or the adhesive rubber layer (extension layer side ) and it may be in the form of embedded between the compression rubber layer.
[0022]
　[Composite Layer
　The composite layer at the bottom of the compression rubber layer is formed without being ground, and a fiber aggregate containing a heat-resistant fiber that does not melt at the vulcanization temperature of the rubber composition constituting the compression rubber layer, the fibers and a vulcanizate of the rubber composition impregnated between fibers of the aggregate (the gap between fibers in the aggregation portion).
[0023]
　(Fiber assembly)
　fiber aggregate has only include a heat-resistant fiber as the main fiber, as long as it does not impair the effects of the present invention, the non-heat-resistant fibers (e.g., polyolefin fibers, acrylic fibers, vinyl fibers , styrenic fibers, polycarbonate fibers, polyurethane fibers, such as thermoplastic elastomeric fiber) may contain. The proportion of heat-resistant fiber is at least 50% by weight, based on the total fiber aggregates, for example, 50 to 100% by weight, preferably 80 to 100% by weight, more preferably about 90 to 100% by weight, 100 parts by mass % may be (heat resistant fiber only).
[0024]
　Heat resistant fibers may be any fiber which does not melt at the vulcanization temperature of the rubber composition constituting the compression rubber layer, may be either organic fibers, inorganic fibers.
[0025]
　The organic fibers, such as natural fibers (cotton, hemp, cellulose-based fibers such as rayon fibers), synthetic fibers [aliphatic polyamide fibers (polyamide 6, polyamide 66, polyamide 46 fiber, etc.), polyester fibers (polybutylene terephthalate , polyethylene terephthalate, poly-C, such as polyethylene naphthalate fiber 2-4 alkylene C 6-14 , such as arylate fibers), such as fluorocarbon fibers (polytetrafluoroethylene fibers), polyacrylic fibers (polyacrylonitrile fibers, etc.), polyvinyl alcohol fibers , polyphenylene sulfide (PPS) fibers, poly -p- phenylene benzobisoxazole (PBO) fibers, aromatic polyamide fibers (p- aramid, m- aramid fibers, etc.), etc.] and the like. As the inorganic fibers, such as carbon fibers, glass fibers, and metal fibers. These heat-resistant fibers may be used singly or in combination. Of these heat-resistant fiber, high modulus of elasticity, from the viewpoint of excellent flexibility, aliphatic polyamide fibers (nylon fibers) or aromatic polyamide fibers (aramid fibers), polyester fibers, preferably organic fibers such as PBO fibers, from the viewpoint of excellent balance between mechanical properties and heat resistance, polyester fibers (in particular polyethylene terephthalate, poly-C, such as polyethylene naphthalate fiber 2-4 alkylene C 6-14 arylate fibers) are particularly preferred. Heat-resistant fibers, for example, a polyester fiber is a major fibers (such as polyethylene terephthalate long fibers), short fibers from compressed rubber layer may be a combination of (cotton fibers, aramid fibers, etc.).
[0026]
　If heat-resistant fiber is an organic fiber, vulcanized since the to retain the fibrous form, the vulcanization temperature (e.g., 140 ~ 200 ° C., particularly 180 about ° C.) may have a softening or melting point greater than, softening point or melting point of the heat-resistant fiber (or decomposition point), when the vulcanization temperature is T, for example, may also be T + 10 ° C. or higher, for example (T + 10) ~ (T + 300) ℃, preferably (T + 20) ~ (T + 200) ℃, more preferably (T + 30) ~ (T + 100) about ° C.. The melting point of heat-resistant fibers, for example, 180 ~ 350 ° C., preferably 200 ~ 300 ° C., more preferably about 250 ~ 280 ° C.. When the softening point or melting point is below the vulcanization temperature, the vulcanization to form a film and loss fiber shape, flexibility of the belt may deteriorate.
[0027]
　Fiber type heat-resistant fiber is not particularly limited, monofilament, multifilament, it may be in any form of the spun yarn (spun yarn), or a combination thereof.
[0028]
　The average fiber diameter of the heat-resistant fiber, for example, 1 ~ 50 [mu] m, preferably 2 ~ 30 [mu] m, more preferably 3 ~ 10 [mu] m (in particular 5 ~ 9 .mu.m) approximately. If the fiber diameter is too large, the flexibility is lowered, there is a possibility that flexibility of the belt is reduced, too small, there is a possibility that air permeability in the belt manufacturing process is reduced.
[0029]
　Fiber length of the heat-resistant fiber is not particularly limited, short fibers (e.g. 1 ~ 500 mm, preferably 3 ~ 300 mm, more preferably short fibers having an average fiber length of about 5 ~ 100 mm) may be, from the viewpoint of excellent like shape stability, long fibers (long fibers infinite fiber length) are preferred. Furthermore, the long fibers as main fibers (such as polyester filament), or may be a combination of short fibers (such as staple fibers from compressed rubber layer) as auxiliary fiber.
[0030]
　Structure of the fiber aggregate may be a knitted woven structure (structure of the knitted fabric or woven fabric), but a rubber composition in terms easily impregnated or penetration between the fibers, non-woven fiber structure (structure of the nonwoven fabric) It is preferred. Nonwoven fibrous structure of the present invention has a structure in which the rubber composition between the fibers of the nonwoven fabric is filled (impregnated) is usually the raw material.
[0031]
　Basis weight of the fiber aggregate 25 g / m 2 as long or less, for example 5 ~ 25 g / m 2 , preferably 7 ~ 23 g / m 2 (e.g. 8 ~ 20 g / m 2 ), more preferably 8 ~ 15 g / M 2 (particularly ～ 12G 8 / M 2 is a) about. Further, from viewpoint of stably producing a high bending resistance belt, the unit weight ~ 11g 6 / m 2 (in particular 7 ~ 10 g / m 2 may be a) about. If the basis weight is too small, there is a possibility that the releasing property and breathability in the belt manufacturing process is lowered, while when too large, or is inhibited integration of the rubber composition, flex resistance may be lowered. Incidentally, the basis weight of the heat-resistant fiber aggregate having a non-woven fiber structure is the same as the basis weight of the nonwoven fabric as a raw material.
[0032]
　Fiber assembly, but fibers may be fused, do not have the viewpoint of improving the bending resistance, fibers (in particular heat-resistant fibers) is not fused to (fused point ) fibers are preferred.
[0033]
　Heat resistant fibers may be randomly oriented, but from viewpoint of improving the strength for a particular direction, preferably oriented in the flow direction (MD), such as the direction in the manufacturing process] predetermined direction. Predetermined direction fiber fiber assembly oriented (especially nonwoven), by the parallel to the longitudinal direction of the belt in the longitudinal direction of the fibers, it is possible to suppress elongation and breakage when pulled in the winding direction (circumferential direction) , it is possible to improve the workability of winding of the belt.
[0034]
　Fiber assembly, as required, within the fiber surface or each fiber, conventional additives, for example, enhancers, fillers, metal oxides, plasticizers, processing agents or processing aids, colorants, coupling agents, stabilizers (UV absorbers, antioxidants, antiozonants, thermal stabilizers), lubricants, a flame retardant, an antistatic agent and the like. The proportion of additives is 10 wt% or less with respect to the entire fiber aggregate (e.g., 0.1 to 5% by weight) is about.
[0035]
　(Vulcanized rubber composition)
　The rubber composition, the rubber composition of the compression rubber layer (included existing or) penetrated between the fibers of the fiber assembly is a rubber composition. The rubber composition is not particularly limited, usually, the rubber composition comprising a rubber component and a vulcanizing agent or crosslinking agent is used. The present invention is particularly, a rubber composition containing sulfur and organic peroxides (particularly organic peroxide vulcanizable rubber composition) form an unvulcanized rubber layer,硫又pressurizing the unvulcanized rubber layer crosslinked it is useful for.
[0036]
　As the rubber component, vulcanization or cross-linkable rubbers such as diene rubber (natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (nitrile rubber), hydrogenated nitrile rubber , a mixed polymer of hydrogenated nitrile rubber and the unsaturated carboxylic acid metal salt), ethylene -α- olefin elastomer, chlorosulfonated polyethylene rubber, alkylated chlorosulfonated polyethylene rubber, epichlorohydrin rubber, acrylic rubber, silicone rubber, urethane rubber, fluorine rubber can be exemplified. These rubber components may be used singly or in combination.
[0037]
　Of these, free of harmful halogen, ozone resistance, heat resistance, has a cold resistance, from the viewpoint of excellent in economical efficiency, ethylene -α- olefin elastomer (ethylene -α- olefin rubber) are preferable. Further, ethylene -α- olefin elastomer has low wettability as compared with other rubbers, may significantly improve the power transmission property and quietness during injection.
[0038]
　The ethylenically -α- olefin elastomer (ethylene -α- olefin rubber), for example, ethylene -α- olefin rubbers, ethylene -α- olefin - diene rubber, and the like.
[0039]
　The α- olefin, e.g., propylene, butene, pentene, methylpentene, hexene, linear alpha-C, such as octene 3-12 such olefins. α- olefin may be used alone or in combination of two or more. Among these α- olefins, alpha-C such as propylene 3-4 olefins (especially propylene) are preferred.
[0040]
　The diene monomer, typically, a non-conjugated diene monomer, for example, dicyclopentadiene, methylene norbornene, ethylidene norbornene, 1,4-hexadiene, etc. cyclooctadiene is exemplified. These diene monomers may be used singly or in combination.
[0041]
　Exemplary ethylene -α- olefin elastomer, such as ethylene -α- olefin rubber (ethylene - propylene rubber (EPR)), ethylene -α- olefin - diene rubber (ethylene - propylene - diene copolymer (EPDM, etc.) ), and others. Preferred ethylene -α- olefin elastomer is EPDM.
[0042]
　In ethylene -α- olefin rubber, the ratio of ethylene and α- olefin (mass ratio), the former / the latter = 40 / 60-90 / 10, preferably 45 / 55-85 / 15 (for example, 50 / 50-82 / 18), more preferably 55 / 45-80 / 20 (for example, may be 55 / 45-75 / 25) approximately. The ratio of diene with respect to the total rubber can be selected from the range of about 4 to 15 wt%, for example 4.2 to 13% by weight (e.g., 4.3 to 12% by weight), preferably from 4.4 to 11 .5 wt% (e.g. 4.5 to 11 parts by mass%) may be about. Incidentally, iodine value of the ethylene -α- olefin rubber containing diene component, for example, 3 to 40 (preferably 5 to 30, more preferably 10 to 20) may be about. Heat when the iodine value is too small, easy wear and adhesive and becomes insufficient vulcanization is generated in the rubber composition, the iodine value is too large, the scorch of the rubber composition becomes cumbersome shorter gender tends to decrease.
[0043]
　As the organic peroxide, typically rubber, organic peroxides used in crosslinking of the resin, for example, diacyl peroxides, peroxy esters, dialkyl peroxides (e.g., dicumyl peroxide, t-Buchirukumirupa peroxide, 1,1-di - butylperoxy-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (t-butylperoxy) - hexane, 1,3-bis (t- butylperoxy - isopropyl) benzene, di -t- butyl peroxide) and the like. These organic peroxides may be used singly or in combination. Furthermore, the organic peroxide, the half-life of one minute due to thermal decomposition 0.99 ~ 250 ° C. (e.g., 175 ~ 225 ° C.) of about peroxide are preferred.
[0044]
　The proportion of the vulcanizing agent or crosslinking agent (especially an organic peroxide) are (such as ethylene -α- olefin elastomer) rubber component per 100 parts by weight, 1 to 10 parts by weight in terms of solid content, preferably 1.2 8 parts by mass to, more preferably 1.5-6 parts by weight (preferably 2 to 5 parts by weight) approximately.
[0045]
　The rubber composition may further contain a vulcanization accelerator. As the vulcanization accelerator, for example, thiuram accelerators, thiazole - Le-based accelerators, sulfenamide-based accelerator, bismaleimide-based accelerators, and the like urea accelerator. These vulcanization accelerators may be used singly or in combination. The proportion of the vulcanization accelerator is a solid basis per 100 parts by mass of the rubber component, for example, 0.5 to 15 parts by weight, preferably from 1 to 10 parts by weight, more preferably about 2 to 5 parts by weight .
[0046]
　The rubber composition increases the degree of crosslinking, in order to prevent a sticky wear, further co-crosslinking agent (a crosslinking aid or co vulcanizing agents) may be contained. The co-crosslinking agent, conventional cross-linking aids such as polyfunctional (iso) cyanurate [e.g., triallyl isocyanurate (TAIC), such as triallyl cyanurate (TAC)], polydienes (e.g., 1,2-polybutadiene etc.), a metal salt of an unsaturated carboxylic acid [for example, (meth) zinc acrylate, (meth) such as magnesium acrylate, oximes (e.g., such as quinone dioxime), guanidines (e.g., diphenylguanidine), polyfunctional (meth) acrylates [for example, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, etc.], bismaleimides (N-N'-m-phenylene bismaleimide and the like) and the like. These crosslinking aids may be used singly or in combination. Ratio of the cross-linking aid (total amount when combining multiple species) is a solid basis, relative to 100 parts by mass of the rubber, for example, 0.01 to 10 parts by weight, preferably 0.05 to 8 parts by mass, further preferably 0.1 to 5 parts by weight.
[0047]
　The rubber composition may optionally contain a conventional additive, for example, vulcanization aid, vulcanization accelerator, vulcanization retarder, enhancers (carbon black, such as silicon oxide, such as hydrated silica), fillers ( clay, calcium carbonate, talc, mica), metal oxides (e.g., zinc oxide, magnesium oxide, calcium oxide, barium oxide, iron oxide, copper oxide, titanium oxide, aluminum oxide), a softener (paraffin oil, naphthene system oil, oils such as process oil, etc.), processing agents or processing aids (stearic acid, stearic acid metal salts, waxes, paraffins, fatty acid amide), antioxidants (antioxidants, thermal aging inhibitors, bent crack-preventing member, such as antiozonants), colorants, tackifiers, and plasticizers, coupling agents (silane coupling agent), a stabilizer (purple Linear absorption agents, such as heat stabilizer), a lubricant, a flame retardant, an antistatic agent and the like. The metal oxide may act as a crosslinking agent. These additives may be used singly or in combination.
[0048]
　The proportion of these additives may be selected from the range of customary, depending on the type, for example, the ratio is 10 to 200 parts by weight of the enhancer relative to 100 parts by mass of the rubber component (carbon black, silica, etc.) (in particular from 20 to may be 150 parts by weight) approximately, metal oxides (the proportion of zinc oxide, etc.) may be about 1 to 15 parts by weight (in particular 2-10 parts by weight), softening agent (oil such as paraffin oil ratio of s) may be about 1 to 30 parts by weight (preferably 5 to 25 parts by mass), the proportion of processing agents (such as stearic acid) 0.1 to 5 parts by weight (especially 0.5 to 3 parts by mass part) may be about.
[0049]
　(Composite layer properties)
　in the present invention, the fiber aggregate comprising a heat-resistant fiber that does not melt by vulcanization of the rubber composition constituting the compression rubber layer is embedded in the surface of the compression rubber layer mixed with the rubber composition (integral to form the reduction) composite layer, can hold the flexibility of fibers, not an obstacle (Brace) at the bent belt, it is possible to improve the durability of the belt, it is possible to suppress fuzz in the compression rubber layer bottom, appearance properties not be impaired. Further, the composite layer, the fiber shape does not disappear in the vulcanization step, because the residual, releasability and breathability in vulcanizing process by fiber geometry, further can secure durability.
[0050]
　Existence form of heat-resistant fibers in the composite layer, in order to ensure the releasability and breathability in the vulcanization process, is preferably at least a portion of the heat resistant fibers are exposed on the surface of the composite layer, the other part, in the interior of the composite layer, it may be embedded in the rubber composition impregnated between fibers. Further, by the majority of the heat resistant fibers are embedded in the rubber composition, it can improve the appearance and durability of the belt.
[0051]
　The average thickness of the composite layer, for example, 0.005 ~ 0.05 mm, preferably 0.006 ~ 0.02 mm, more preferably 0.007 ~ 0.015 mm (particularly 0.008 ~ 0.012 mm) approximately. If the thickness is too thin, there is a possibility that the releasing property and breathability in the belt manufacturing process is reduced, too thick, there is a fear that bending resistance is reduced. The average thickness of the composite layer, heat-resistant fibers embedded in the compression rubber layer can be measured based on the measurement of the buried depth in any 10 places in the bottom surface of the compression rubber layer to be measured by obtaining an average value.
[0052]
　Compression Rubber Layer
　compression rubber layer, the same rubber composition and the rubber composition contained in the composite layer is formed by further as a reinforcing fiber, polyamide staple fibers, such as aramid short fibers, polyester staple fibers, vinylon it may contain short fibers such as short fibers. The proportion of the reinforcing fibers may be 80 parts by mass or less with respect to 100 parts by mass of the rubber component, for example, 1 to 80 parts by weight, preferably 3 to 60 parts by weight, more preferably 5 to 50 parts by weight (in particular 10 ~ 45 parts by weight) approximately. If the proportion of the short fibers is too small, there is a possibility that the durability of the belt is reduced.
[0053]
　Compression rubber layer does not have the like nonwoven fabric layer in the layer, it is preferable that the rubber composition forms a continuous phase. Therefore, the rubber component is not divided in the layer, it is possible to improve the durability of the belt.
[0054]
　The average thickness of the compression rubber layer, for example, 2 ~ 20 mm, preferably 2.5 ~ 15 mm, more preferably about 3 ~ 10 mm.
[0055]
　[Other layers and core]
　Similar rubber composition and the compressed rubber layer to the adhesive rubber layer (rubber composition containing a rubber component such as ethylene -α- olefin elastomer) can be used. In the rubber composition of the adhesive rubber layer, the rubber component, often use rubber of the rubber component and the same type or the same type of rubber composition of the compression rubber layer. Further, a vulcanizing agent or crosslinking agent, co-crosslinking agent or a crosslinking aid, the percentage of additives such as vulcanization accelerators may, respectively, be selected from the same range as the rubber composition of the compression rubber layer. The rubber composition of the adhesive rubber layer is further adhesion improving agent (resorcinol - formaldehyde co-condensation product, such as amino resins) may be contained. The average thickness of the adhesive rubber layer, for example, 0.4 ~ 3 mm, preferably 0.6 ~ 2 mm, more preferably about 0.8 ~ 1.5 mm.
[0056]
　No particular limitation is imposed on the core body, usually helically spun the core wire (twisted cord) is used in the longitudinal direction of the belt, cord is not in parallel to parallel embedded at predetermined intervals in the longitudinal direction of the belt it may be.
[0057]
　Cord is high modulus fibers, such as polyester fibers (polyalkylene arylate-series fiber), synthetic fibers such as aramid fibers, inorganic fibers such as carbon fibers are generic, polyester fibers (polyethylene terephthalate fiber, polyethylene naphthalate system fibers), aramid fibers are preferred. Fiber multifilament yarn, for example, fineness of 2,000 to 10,000 denier may be (especially 4000-8000 denier) about a multi-filament yarn.
[0058]
　The core typically multifilament yarns twisted using code (e.g., plying, twisting pieces, etc. twisted Lang) can be used. The average wire diameter of the core wire (fiber diameter of the twisted cord) is, for example, 0.5 ~ 3 mm, preferably 0.6 ~ 2 mm, more preferably about 0.7 ~ 1.5 mm.
[0059]
　To improve the adhesion to the polymer component, the core wire is an epoxy compound, after performing various adhesion treatment with an isocyanate compound, is embedded between the extension layer and the compression rubber layer (particularly the adhesive rubber layer) it may be.
[0060]
　If the strained layer is formed in an outer skin, the outer skin, for example, a woven fabric, a wide angle canvas, knitted fabric, or may be a fabric material such as a nonwoven fabric (preferably woven). If the strained layer is formed of a rubber composition, the rubber composition forming the stretching layer may be formed of a rubber composition forming the compression rubber layer. The thickness of the strained layer, for example 0.8 ~ 10 mm, preferably 1.2 ~ 6 mm, more preferably about 1.6 ~ 5 mm.
[0061]
　[V-ribbed belt and a manufacturing method thereof]
　The average thickness of the V-ribbed belt of the present invention may be selected from the range of about 2 ~ 12 mm, for example, 2.5 ~ 10 mm, and preferably about 3.8 ~ 5 mm, for example 4.1 it may be about ~ 4.3mm. The average thickness of the rib can be selected from the range of about 1 ~ 3.5 mm, for example 1.2 ~ 3 mm, preferably 1.5 ~ 2.7 mm, more preferably about 1.6 ~ 2 mm. The average thickness of the rib portion may be not more than 54% relative to the average thickness of the entire belt, and preferably about 36 to 53%.
[0062]
　In the present invention, the bottom surface of the rib portion and the composite layer is formed, is excellent in durability of the belt, it is possible to reduce the thickness of the rib. For example, conventional belt thickness 4.3 ± 0.3 mm, when the rib height 2.0 ± 0.2mm, (2.0 → 1.8mm) by reducing 0.2mm the rib height, the belt it is possible to reduce the thickness to 4.1 ± 0.3mm. On which it can be reduced rib height, since conventionally required grinding allowance (grinding for the bottom of the rib) is not required, thereby reducing the amount of the rubber composition constituting the belt. Further, since the grinding amount is reduced, the grinding time and grinding dust can be reduced. Moreover, amount that the belt thickness is reduced, because the flexibility of the belt is improved, crack resistance is improved by the stress decreased, fuel economy is improved by reducing the bending loss.
[0063]
　Method for manufacturing a V-ribbed belt of the present invention, stretching layer mounting step of mounting the stretching layer member for forming a stretching layer on a cylindrical drum, core spinning process further winding the core wire as a core member, further compressed rubber step with compression rubber layer winding of winding the unvulcanized rubber sheet for forming the layer on the unvulcanized rubber sheet wound further step with fiber aggregate winding that winds the fiber aggregate comprising a heat-resistant fiber, said vulcanization process to obtain a vulcanized belt sleeve by vulcanizing the belt shaped body (unvulcanized belt sleeve) obtained by the respective steps, the fiber assembly side of the vulcanized belt sleeve, grinding only side of the compression rubber layer in comprising a grinding step of shaping.
[0064]
　Specifically, in the manufacturing method of the present invention, as expansion layer attaching step, attaching the stretched layer member on a cylindrical molding drum. As a method of mounting extension layer member can be selected according to the type of the extension layer member, when the sheet-like member may be wound around a member for strained layer on a cylindrical drum, in the case of the annular member, for stretching layer members may be placed over the cylindrical drum.
[0065]
　In the present invention, if necessary, as a pre-process and / or post-process the core spinning process, it may contain an adhesive rubber layer attaching step of attaching the adhesive rubber layer. If the pre-process includes an adhesive rubber layer mounting step, the adhesive rubber layer mounting step, for example, the annular laminated body of a member for forming the unvulcanized rubber sheet and stretching layer for forming the adhesive rubber layer the method for covering a cylindrical drum, a method of winding on a cylindrical drum a laminate of a member for forming the unvulcanized rubber sheet and stretching layer for forming the adhesive rubber layer, on the strained layer member mounted it may be a method of winding the unvulcanized rubber sheet for forming the adhesive rubber layer. If the post-process including the adhesive rubber layer mounting step, the adhesive rubber layer mounting step, for example, a method of winding an unvulcanized rubber sheet for forming the adhesive rubber layer on a core wire, to form an adhesive rubber layer it may be a method of winding on the core laminate of the member for forming an unvulcanized rubber sheet and the compression rubber layer for.
[0066]
　Therefore, in the core spinning process, usually in response to the presence or absence of the adhesive rubber layer winding process, the above unvulcanized sheet for stretching layer member or adhesive rubber layer is attached in step helical cardiac linear spinning and winding in to. Further, in the compression rubber layer winding process, usually the unvulcanized rubber for forming the compression rubber layer (ribbed rubber layer) on the spinning the core or unvulcanized sheet for adhesive rubber layer wound in the step wrapping a sheet.
[0067]
　Furthermore, in the present invention, in the step with fiber aggregate winding, the unvulcanized rubber sheet surface to form a compression rubber layer, fiber aggregate containing a heat-resistant fiber that does not melt at the vulcanization temperature of the rubber composition (In particular, non-woven fabric) wound. When said heat-resistant fiber is oriented in a predetermined direction it is preferably wound in the longitudinal direction of the heat-resistant fiber by parallel to the longitudinal direction of the belt.
[0068]
　Basis weight of the fiber assembly before heat treatment (especially nonwoven) is 5 ~ 50 g / m 2 may be selected from the range of about, for example, 6 ~ 30 g / m 2 , preferably 8 ~ 20 g / m 2 , more preferably 8 ~ 15 g / m 2 (in particular 8 ~ 12 g / m 2 is) about. The average thickness of the fiber assembly before heat treatment (especially nonwoven), for example 0.02 - 0.15 mm, preferably 0.03 to 0.15 mm, more preferably 0.03 to 0.1 mm (particularly from 0.03 to 0.05mm) is about. If the basis weight and thickness of the fiber aggregate is too small, on the releasability and breathability in the vulcanization step may be decreased, the fiber aggregate during the molding (winding for each member before vulcanization) there is a possibility that can not be wound torn and pull. On the other hand, when the basis weight and thickness of the fiber aggregate is too large, a gap between fibers is reduced, there is a fear that the rubber component is hardly enters between the fibers. Further, the fiber assembly becomes rigid, there is a fear that wound becomes difficult.
[0069]
　The vulcanization process, vulcanization type may be vulcanizer scheme. Vulcanizing temperature can be selected according to the type of rubber, for example, 140 ~ 200 ° C., preferably from 0.99 ~ 180 ° C., further preferably about 165 ~ 180 ° C.. If the vulcanizing temperature is too low, there is a possibility that the rubber composition becomes difficult to impregnate between the fibers of the fiber aggregate is too high, there is a possibility that fiber shape is lost. In the present invention, the vulcanization step, (the rubber composition is impregnated in between the fibers of the fiber assembly) for integrating the rubber composition located on the bottom surface of the fiber assembly and the compression rubber layer, the fiber assembly adhesion treatment of the body is not required, higher productivity. Further, the vulcanization, fiber aggregate order to make buried remains compressed rubber layer to some extent maintaining the form of fibers, the air vent and the vulcanization is also effective to release from vulcanized jacket.
[0070]
　The grinding process usually, after formation of the ribs in the compression rubber layer by grinding the vulcanized belt sleeve, V-ribbed belt is obtained by cutting in round slices at a predetermined width. As the grinding method can utilize conventional methods, in the fiber assembly side of the compression rubber layer, for grinding only side of the compression rubber layer, with the composite layer is formed on the bottom surface, the amount of grinding can be reduced .
Example
[0071]
　Hereinafter, the present invention will be described in more detail with reference to Examples, the present invention should not be construed as being limited thereto. Incidentally, showing nonwoven fabric used in Example, the details of the components of the rubber composition and the core (core wire), the evaluation method of the measured endpoints below.
[0072]
　[Nonwoven fabric]
　(Examples 1-5 Polyethylene terephthalate (PET) nonwoven fabric: Hirose Paper Co., Ltd., melting point 260 ° C., no heat Chakuten)
　Example 1: trade name "05th-8", basis weight 8 g / m 2 , the thickness 0.03mm
　example 2: trade name "05th-12", basis weight 12 g / m 2 , thickness 0.04mm
　example 3: trade name "05th-15", basis weight 15 g / m 2 , thickness 0.04mm
　example 4: trade name "05th-20", basis weight 20 g / m 2 , thickness 0.07mm
　example 5: trade name "05th-20H", basis weight 20 g / m 2 , thickness 0.05 mm
　(polyethylene of example 6 terephthalate (PET) nonwoven fabric: Toyobo Co., Ltd., melting point 260 ° C., there thermal fusion point)
　example 6: trade name "3151AD", basis weight 15 g / m 2 , thickness 0.12 mm
　(Comparative example nonwoven)
　Comparative example : Rayon nonwoven fabric, Shinwa Co., Ltd., trade name "# 5130", basis weight 30 g / m 2 , thickness 0.4 mm, melting point (softening point) None
　Comparative Example 2 and 3: low density polyethylene (PE) nonwoven fabric, Idemitsu Unitech Co., Ltd. under the trade name "Stora Tech LL", basis weight 30G / M 2 , thickness of 0.3mm, the melting point 130 ℃
　Comparative Example 4: Polypropylene (PP) nonwoven fabric, Asahi Kasei Fibers Corp., trade name "PL2020", basis weight 15 g / m 2 , thickness 0.14 mm, melting point 165 ° C., there thermal fusion point
　Comparative Example 5: Polypropylene (PP ) non-woven fabric, Idemitsu Unitech Co., Ltd. under the trade name "Stora Tech RN2030", basis weight 30G / M 2 , thickness 0.24mm, melting point 165 ℃, there is heat-sealed point
[0073]
　[Components of rubber
　composition] EPDM polymers: DuPont Dow Elastomer Japan Ltd. "IP3640", Mooney viscosity 40 (100 ° C.)
　polyamide staple fibers: manufactured by Asahi Kasei Corporation, "66 nylon"
　carbon black HAF: Tokai Carbon ( Ltd.) "SEAST 3"
　paraffinic softener: Idemitsu Kosan Co., Ltd., "Diana process oil"
　organic peroxide: Kayaku Akzo Co., Ltd., "Perkadox 14RP"
　hydrated silica: Tosoh silica Corp. "Nipsil VN3", a specific surface area of 240 m 2 / g
　antioxidant: Seiko chemical Co., Ltd. "NONFLEX OD3"
　vulcanization accelerator DM: di-2-benzothiazolyl disulfide.
[0074]
　[Core (core wire)
　core wire: 1,000 denier PET fibers 2 × in twist structure of 3, upper twist factor 3.0, the total denier 6,000 were twisted cord under twist factor 3.0 adhesion treated fiber code.
[0075]
　[Releasability for vulcanizing jacket]
　In the production of the belt in the examples and comparative examples, to observe the state of vulcanization belt sleeve removing the vulcanized jacket, was evaluated according to the following criteria.
[0076]
　　A: outer circumferential surface of the vulcanized belt sleeve (corresponding to the surface of the compression rubber layer bottom) can be easily peeled off without adhesive vulcanized jacket
　　B: outer peripheral surface of the vulcanized belt sleeve is separated by adhesive vulcanization jacket hard to (tool required). Pattern rubbing on the surface is inferior in appearance occurred.
[0077]
　[Heat Durability
　running test machine used for the test of the heat resistance, the drive pulley (diameter 120 mm), idler pulley (diameter 85 mm), a driven pulley (diameter 120 mm), by placing a tension pulley (diameter 45 mm) configuration It is. The winding angle is 90 ° to the tension pulley, to suspend the V-ribbed belt pulleys as winding angle to the idler pulley is 120 °, ambient temperature 120 ° C., the V-ribbed belt at a rotational speed 4900rpm of the drive pulley It was allowed to run. At this time, the load imparted to the drive pulley so that the belt tension 40 kgf / rib gave load 8.8kW to the driven pulley. The thus caused to run a V-ribbed belt, a crack reaching the core was measured the time until six occurs.
[0078]
　[Flex fatigue resistance (crack resistance)
　by using a testing machine of a layout shown in FIG. 2, a V-ribbed belt obtained in the Examples and Comparative Examples subjected to running test V-ribbed belt under 130 ° C. atmosphere, the rib portion measuring the time until cracks occur in the evaluated the bending fatigue resistance. The measurement was performed two or more times with the exception of Comparative Example 1, the mean value was calculated and the variation (difference between the maximum value and the minimum value).
[0079]
　[Evaluation of Appearance Properties]
　observed a rib tip surface of the V-ribbed belt obtained in Examples and Comparative Examples was visually judged according to the following criteria.
[0080]
　　4: the rib tip surface is no mass of fluffing of the nonwoven fabric of fibers or skin layer
　　3: mass of fuzz of some non-woven fabric of fibers of the rib tip surface or skin layer is slightly inconspicuous
　　2: the rib tip surface There are mass fuzz or skin layers of fibers of the nonwoven fabric, slightly noticeable
　　1: the whole of the rib tip surface is mass of fuzz or skin layers of non-woven fibers.
[0081]
　Incidentally, the "fluff" in the evaluation criteria, the rib tip surface is meant to include filamentous material of the following conditions (1) and (2).
[0082]
　(1) filamentous material fiber shape is maintained in the non-woven fabric is, the state appearing on the bottom surface not completely embedded in the rubber
　when grinding (2) side, a bottom fibrous form which has been embedded in the (composite layer) state filamentous material was maintained, came out on the surface are pulled out of the composite layer under the influence of grinder.
[0083]
　Examples 1-6 and Comparative Examples 1-5
　(outer skin to form the extension layer)
　as an outer skin, plain weave fabric of wide angle using混撚yarn 50:50 cotton fibers and polyethylene terephthalate fibers in a weight ratio ( thickness 0.63mm) was used. After immersing these canvas in RFL solution, and the adhesive treated canvas was heat treated for 2 minutes at 0.99 ° C.. Further, in this bonding process canvas, to prepare a rubber sheet laminate obtained by laminating (thickness 0.5 mm) to form an adhesive rubber layer obtained by the rubber composition shown in Table 1.
[0084]
　(Compression rubber layer, and the rubber sheet for forming the adhesive rubber layer)
　of the rubber composition shown in Table 1 were kneaded in a Banbury mixer, by rolling by a calender roll, a rubber sheet for forming a compression rubber layer a thickness of 2.2 mm, and the rubber sheet for forming the adhesive rubber layer were prepared in a thickness of 0.5 mm.
[0085]
[Table 1]

[0086]
　(Belt manufacture)
　on the outer periphery of the smooth surface cylindrical drum (molding die), the laminate formed by laminating a rubber sheet for forming the outer skin and the adhesive rubber layer for forming a stretching layer, the adhesive rubber sheet for forming the rubber layer is wound so that the outer peripheral surface. After winding the cord spirally on the outer peripheral surface of the laminate, further on this core wire and a rubber sheet for forming the rubber sheet and the compression rubber layer for forming the adhesive rubber layer are laminated the laminate rubber sheet for forming a compression rubber layer is wound so that the outermost surface. Furthermore, wound nonwoven this outermost surface, to produce a belt shaped body of unvulcanized (unvulcanized belt sleeve).
[0087]
　Further, disposed in a state covered with the vulcanized jacket on the outer peripheral side of the belt shaped member in the vulcanizer, the pressurized steam, 180 ° C., 0.9 MPa, were vulcanized at the 25 minute conditions.
[0088]
　Furthermore, after cooling, remove the vulcanized jacket (release with) the vulcanized belt sleeve thus obtained, the compressed rubber at the grinding wheel having a predetermined shape to form a V-shaped groove (grindstone) by grinding only the sides of the layers to form a plurality of ribs (V-shaped groove). Then, the vulcanized belt sleeve the plurality of ribs are formed, cut into a predetermined width to slicing by a cutter, by reversing the inner and outer circumferential sides, V of the cross-sectional structure shown in FIG. 1 ribbed belt was obtained.
[0089]
　The rib portion surfaces of the V-ribbed belt obtained in Example, nonwoven, embedded in a portion of the fibers are compressed rubber layer in a state exposed on the surface, was composite layer is formed. Scanning electron micrographs of the rib portion surfaces of the V-ribbed belt obtained in Example 1 (SEM photograph), shown in FIG. 3, thin linear portion is a moiety derived from a nonwoven fabric, the other portions are portions derived from the compression rubber layer. As apparent from FIG. 3, the rib surface of the V-ribbed belt of Example 1, the composite layer and the nonwoven fabric and the rubber composition are mixed was formed. Specifically, about 3, the central portion the fibrous portion can be observed is the surface of the bottom (unground surface), right and left side portions are ground surface.
[0090]
　In Comparative Example 3 was prepared a V-ribbed belt by a method using a mold described in Example of JP-2013-145032.
[0091]
　(Evaluation of the belt)
　showing heat resistance of the produced V-ribbed belt, the bending fatigue resistance, the evaluation results of appearance of the rib portion surfaces in Table 2.
[0092]
[Table 2]

[0093]
　As apparent from the results in Table 2, the bottom of the compression rubber layer as in Examples 1-6 of a rubber composition to form a composite layer impregnated between fibers of the nonwoven fabric, the nonwoven fabric is melted, who lost fiber form comparing Comparative examples 2 and 3 formed single film-like resin layer (skin layer), examples 1-6, heat resistance, long time until cracks occurred in flexural fatigue resistance both durability It was superior to sex.
[0094]
　In Comparative Examples 4 and 5 using a polypropylene nonwoven, heat-treated product of the nonwoven fabric is formed of a fibrous part fiber form remained, the non-fibrous portion fibrous form is lost. Therefore, the composite layer, embodiment 3 components of the fibrous portion and a non-fibrous portion and the rubber component to form a structure mixed heat durability by remaining fiber shape, flexural fatigue resistance was used PET nonwoven it is equivalent to 1 to 6. However, the belt comprising a melt of the fibrous part (Comparative Example 2-5), poor releasability from the vulcanization jacket after vulcanization, additionally, variations in the bending fatigue resistance of the test result is greater stability since is not obtained, it lacked practicality.
[0095]
　Further, as in Examples 1-6, nonwoven as in Example 1-6 when comparing the Comparative Example 1 it remains fiber form, the Examples 1-6 were excellent in durability than the comparative Example 1 .
[0096]
　From the above, the surface of the bottom portion of the compression rubber layer, Example rubber composition is a composite layer impregnated between fibers of PET non-woven fabric, the surface of the bottom portion of the compression rubber layer is a film-like resin layer (skin layer) Ya compared to Comparative example is a thick non-woven fabric, easy belt bends, it was excellent in durability. The surface of the bottom portion of the compression rubber layer, compared with Comparative Example is a melt of nonwoven fibrous shape remained, it was excellent in releasability from a vulcanized jacket.
[0097]
　Furthermore, among Examples, the smaller nonwoven basis weight and thickness, the time until cracking occurs in the bending fatigue test is prolonged.
[0098]
　Further, the basis weight for the same nonwoven fabric, as in Example 3 heat Chakuten no, comparing the Example 6 with a heat Chakuten Trip Example 3 was excellent in durability. When heat Chakuten there, it can be estimated that for flexibility and nonwoven fabric becomes thick drops. In addition, stress is concentrated to heat Chakuten, it can be estimated to be the influence that tends to be cracked at the time of bending.
[0099]
　The appearance, the fluff of the nonwoven fabric at the entire bottom surface of the compression rubber layer is compared with the belt of Comparative Example 1 that occurs, the belt of Examples 1-6, or no fluffing of the nonwoven fabric, inconspicuous, is a good appearance It was.
[0100]
　Shows a photograph of the rib portion of the V-ribbed belt obtained in Example 1 in FIG. 4, scratches and stains from vulcanizing jacket not transferred, the appearance was good. That is, in the SEM photographs, although a nonwoven fabric can be observed, the visual nonwoven was not noticeable.
[0101]
　Although a photograph of the rib portion of the V-ribbed belt was manufactured without using the nonwoven fabric in FIG. 5 (Reference Example 1), scratches and stains were transcribed from vulcanized jacket.
[0102]
　The present invention in detail, also has been described with reference to specific embodiments, without departing from the spirit and scope of the present invention, it is possible that various modifications and changes will be apparent to those skilled in the art.
　This application is, 2015 September 29, filed the Japanese patent application 2015-191401, and is based on the 2016 September 8, Japanese Patent Application date application 2016-175415, the contents of which are incorporated herein by reference.
Industrial Applicability
[0103]
　V-ribbed belt of the present invention can be used as a friction transmission belt of the transmission device such as an automobile engine accessory drive.
DESCRIPTION OF SYMBOLS
[0104]
　1 ... stretching layer
　2 ... core (core wire)
　3 ... adhesive rubber layer
　4 ... compression rubber layer
　4a ... grinding surface
　5 ... composite layer

claims

[Claim 1]Together and a compression rubber layer and the core and the strained layer containing vulcanized rubber composition, a grinding surface side of the compression rubber layer is in contact with the pulley, and a bottom portion of the compression rubber layer and a pulley a V-ribbed belt is unground surface that does not contact,
　the the surface of the bottom, comprises a heat-resistant fiber that does not melt at the vulcanization temperature of the rubber composition and basis weight 25 g / m 2 fiber assembly is less When, V-ribbed belt having a composite layer containing an vulcanizates of the rubber composition impregnated between fibers of the fiber assembly.
[Claim 2]
　V-ribbed belt according to claim 1 heat-resistant fiber comprises a polyester fiber.
[Claim 3]
　V-ribbed belt according to claim 1 or 2 fiber aggregate has a non-woven fibrous structure.
[Claim 4]
　Basis weight of the fiber aggregate is ~ 20 g 8 / m 2 V-ribbed belt according to any one of claims 1 to 3, which is.
[Claim 5]
　V-ribbed belt according to any one of claims 1 to 4, the compression rubber layer forms a continuous phase in vulcanized rubber composition.
[Claim 6]
　V-ribbed belt according to any one of claims 1 to 5 having an average fiber diameter of the heat-resistant fiber is 1 ~ 50 [mu] m.
[Claim 7]
　V-ribbed belt according to any one of claims 1 to 6, heat-resistant fiber comprises long fibers.
[8.]
　V-ribbed belt according to any one of claims 1 to 7, heat-resistant fibers are not fused.
[Claim 9]
　V-ribbed belt according to any one of claims 1 to 8 compression rubber layer contains short fibers.
[Claim 10]
　Fiber aggregate has a non-woven fibrous structures, heat-resistant fibers are oriented in a predetermined direction, either longitudinally claim 1 which is parallel to the longitudinal direction of the belt 9 of the heat-resistant fiber one V-ribbed belt according to the item.
[Claim 11]
　Compression rubber layer has a rib portion, and the V-ribbed belt according to any one of claims 1 to 10 the average thickness of the rib is not more than 54% relative to the average thickness of the entire V-ribbed belt.
[Claim 12]
　Stretching layer mounting step of mounting the stretching layer member for forming a stretching layer on a cylindrical drum, core spinning step of winding the core wire as a further core body, the unvulcanized rubber to further form a compression rubber layer step with compression rubber layer winding of winding the sheet, wound was on the unvulcanized rubber sheet, further steps with fiber aggregate winding that winds the fiber aggregate comprising a heat-resistant fiber, the resulting belt shaped member by the steps vulcanized vulcanized obtaining a vulcanized belt sleeve, the fiber assembly side of the vulcanized belt sleeve, any one of claims 1 to 11 including a grinding step of forming only the side of the compression rubber layer in grinding method for manufacturing a V-ribbed belt according to.
[Claim 13]
　The process according to claim 12 the average thickness of the fiber aggregate is 0.03 ~ 0.15 mm.