JP2002257199A - Power drive belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power drive belt of which the main rubber material is made of chloroprene rubber having an excellent effect for inhibiting adhesive wear. SOLUTION: In a V-ribbed belt wherein a core wire 3 is buried in an adhesive rubber layer 2 along the longitudinal direction and a compressive rubber layer 4 is provided under the wire, at least the compressive rubber layer 4 is composed of the chloroprene rubber as the main rubber material, and a rubber composition composed of a metal oxide, an organic peroxide and α,β-unsaturated aliphatic metallic salt is used for the belt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission belt, and more particularly, to a power transmission belt using a rubber composition mainly composed of chloroprene rubber as at least a part of a rubber member constituting the power transmission belt. About the belt.

[0002]

2. Description of the Related Art In recent years, with the advancement of functions and performance of automobile parts, especially in the rubber industry, there has been a demand for rubber products that can withstand severe use environments. The properties of rubber products are determined by the selection of raw rubber and the combination of compounding agents. Among them, since the network chain density and the crosslinked structure are closely related to the physical properties of the rubber crosslinked product, the selection of the compounding agent for crosslinking is an important position in the design.

A typical example of a rubber used for a belt material is chloroprene rubber. Chloroprene rubber is a homopolymer of 2-chlorobutadiene and has uniform properties based on Cl in the side chain, such as heat resistance, ozone resistance, weather resistance, oil resistance, and chemical resistance. And is used for a wide range of applications.

[0004] Crosslinking of chloroprene rubber is generally carried out in combination with a metal oxide and a vulcanization accelerator. Crosslinking with a metal oxide gives a crosslinked product ion-bonded by the reaction between the functional group in the rubber molecular chain and the metal oxide, but when the crosslinked product is used for a belt, sticky wear occurs due to friction with a pulley. Therefore, there is a problem that noise is generated due to adhesion during traveling. In order to prevent this adhesive wear, it is conceivable to set a high crosslinking density. However, in this vulcanization system, even if a vulcanization accelerator is further added, the crosslinking density and mechanical properties are not largely changed. There was also a problem that a large amount of the accelerator was caused to cause bloom. It is also conceivable to increase the elasticity by blending a reinforcing filler such as carbon black. However, rubber showing extensible crystallinity such as chloroprene rubber has a small effect because the crystal part plays the role of a reinforcing agent.

[0005]

As a result of intensive studies based on the above findings, at least a part of the rubber member constituting the power transmission belt has chloroprene rubber as a main material rubber, a metal oxide and an organic peroxide. Oxides and α, β-
It has been found that the use of a rubber composition containing an unsaturated fatty acid metal salt can suppress adhesive wear. For more information,
The power transmission belt using the rubber composition has a crosslinked structure composed of an ionic bond crosslinked chain formed by metal oxide crosslinking and a C—C bonded crosslinked chain formed by organic peroxide crosslinking, and is a co-crosslinking agent. By controlling the degree of cross-linking with α, β-unsaturated fatty acid metal salt, it is possible to prevent sticking and abrasion and to have excellent mechanical properties. Especially, it is used for the compression rubber layer of the belt used for power transmission etc. It is found that it is effective for pronunciation measures.

[0006]

That is, in the invention of claim 1 of the present application, a rubber containing chloroprene rubber as a main material rubber, and compounding a metal oxide, an organic peroxide and a metal salt of an α, β-unsaturated fatty acid. A power transmission belt in which the composition is used for at least a part of a rubber member constituting the power transmission belt.

According to a second aspect of the present invention, there is provided the power transmission belt according to the first aspect, wherein 0.25 to 1 part by mass of an organic peroxide is blended with respect to 100 parts by mass of a rubber component. On the belt. By setting the compounding amount of the organic peroxide within the above range, it is possible to suppress adhesive wear without extremely reducing mechanical properties such as dynamic fatigue resistance and flex fatigue resistance.

According to a third aspect of the present invention, in the power transmission belt according to the first or second aspect, 1 to 25 parts by mass of an α, β-unsaturated fatty acid metal salt is blended with 100 parts by mass of the rubber component. Power transmission belt.

According to a fourth aspect of the present invention, there is provided a power transmission belt according to any one of the first to third aspects, wherein α, β-
The metal salt of unsaturated fatty acid is a power transmission belt which is a metal salt of acrylic acid.

According to a fifth aspect of the present invention, in the power transmission belt according to the fourth aspect, the metal acrylate is a power transmission belt which is at least one selected from aluminum acrylate and zinc acrylate. is there.

According to a sixth aspect of the present invention, there is provided a power transmission belt according to any one of the first to fifth aspects, wherein the power transmission belt is an adhesive rubber layer in which a cord is embedded along a belt length direction. And a compressed rubber layer having a plurality of rib portions extending in the belt length direction. At least the compressed rubber layer is a power transmission belt made of the rubber composition.

According to a seventh aspect of the present invention, in the power transmission belt according to any one of the first to fifth aspects, the power transmission belt is an adhesive rubber layer in which a cord is embedded along a belt length direction. And a V-belt comprising a compression rubber layer,
At least the compressed rubber layer is a power transmission belt made of the rubber composition.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power transmission belt which receives friction repeatedly, specifically, a V-ribbed belt or a V-belt which transmits friction, using chloroprene rubber as a main material rubber, metal oxide and organic peroxide. Further, there is provided a power transmission belt in which a rubber composition containing an α, β-unsaturated fatty acid metal salt is used for at least a part of a rubber member constituting the power transmission belt. Among them, it is desirable to use the rubber composition for the compressed rubber layer that is always in contact with the pulley, in order to prevent adhesive wear.

FIG. 1 is a sectional perspective view of a V-ribbed belt as an example of a power transmission belt. This V-ribbed belt 1
Has a core wire 3 made of a cord of high strength and low elongation embedded in the adhesive rubber layer 2 along the belt length direction, and a compression rubber layer 4 as an elastic layer is provided below the core wire 3. . The compression rubber layer 4 is provided with a plurality of ribs having a substantially inverted trapezoidal cross section extending in the longitudinal direction of the belt, and a base fabric 5 is laminated on the back of the belt as an extension layer.

As the core wire 3, polyester fiber, aramid fiber and glass fiber are used.
Adhesive-treated cords having a total denier of 4,000 to 8,000, in which polyester fiber filaments mainly composed of 2,6-naphthalate are twisted, can lower the belt slip rate and extend the life of the belt. Preferred. The twist number of this cord is 10-23 / 10
cm, and the number of twists is 17 to 38/10 cm. If the total denier is less than 4,000, the modulus and strength of the cord become too low, and if it exceeds 8,000, the belt becomes thick and the bending fatigue becomes poor.

Ethylene-2,6-naphthalate is usually synthesized by condensation polymerization of naphthalene-2,6-dicarboxylic acid or an ester-forming derivative thereof with ethylene glycol under appropriate conditions in the presence of a catalyst. . At this time, if one or more appropriate third components are added before the completion of the polymerization of ethylene-2,6-naphthalate, a copolymer polyester is synthesized.

The core wire 3 is subjected to an adhesive treatment for the purpose of improving the adhesiveness with rubber. As such an adhesive treatment, the fiber is made of resorcin-formalin-latex (RF
L) Generally, after immersion in the liquid, the adhesive layer is uniformly formed on the surface by heating and drying. However, without being limited to this, there is a method of performing a pretreatment with an epoxy or isocyanate compound and then treating with an RFL solution.

The cord having been subjected to the adhesive treatment can be finished into a belt having a high modulus by setting the spinning pitch, that is, the winding pitch of the core wire to 1.0 to 1.3 mm. If it is less than 1.0 mm, the cord runs over the adjacent cord and cannot be wound, while if it exceeds 1.3 mm, the modulus of the belt gradually decreases.

The base cloth 5 is a base cloth selected from a woven fabric, a knitted fabric, and a non-woven fabric. As the fiber material constituting the base fabric, known and publicly-known ones can be used.For example, natural fibers such as cotton and hemp, metal fibers, inorganic fibers such as glass fibers, and polyamide, polyester, polyethylene, polyurethane,
Polystyrene, polytetrafluoroethylene, polyacryl, polyvinyl alcohol, wholly aromatic polyester,
Organic fibers such as aramid are exemplified. The base cloth 5 is immersed in a resorcinol-formalin-latex liquid (RFL liquid) according to a known technique, and then friction is applied to rub the unvulcanized rubber on the base cloth 5. Immerse in a dissolved soaking solution.

The RFL solution is a mixture of an initial condensate of resorcinol and formalin and a rubber latex. The molar ratio of resorcinol to formalin is preferably 1: 0.5 to 3 in order to enhance the adhesive strength. is there. The initial condensate of resorcinol and formalin was mixed with latex such that the resin content was 10 to 100 parts by mass with respect to 100 parts by mass of the rubber component of the latex, and the total solid content was 5 to 40 parts by mass. The concentration is adjusted to be a concentration by mass. Note that R
The FL liquid may be appropriately mixed with a carbon black liquid to blacken the treated material, or a known surfactant may be added in an amount of 0.1 to 5.0% by mass. Examples of the latex include styrene-butadiene-vinylpyridine terpolymer, chlorosulfonated polyethylene, hydrogenated nitrile rubber, epichlorohydrin, natural rubber, SBR, chloroprene rubber, olefin-vinyl ester copolymer, EPDM and the like. Latex is mentioned.

The compressed rubber layer 4 is a rubber composition composed of chloroprene rubber as a main rubber and a metal composition containing a metal oxide, an organic peroxide and a metal salt of an α, β-unsaturated fatty acid. If necessary, a reinforcing agent such as carbon black, a filler, a softening agent, an antioxidant, a vulcanization aid, and sulfur are added and mixed. By using the rubber composition, it is possible to provide a friction transmission belt in which adhesive wear is suppressed and noise during traveling is reduced. The chloroprene rubber can be roughly classified into a sulfur-modified type and a non-sulfur-modified type, but the present invention is not particularly limited.

In the present invention, a metal oxide and an organic peroxide are used in combination as a crosslinking agent. Examples of the metal oxide include zinc oxide, magnesium oxide, calcium oxide, and the like, and the amount of the metal oxide is preferably 1 to 15 parts by mass with respect to 100 parts by mass of the rubber component. The metal oxide is 1
Although it is possible to use a single species or to use two or more species together, it is preferable to use a combination of zinc oxide and magnesium oxide. In addition, the metal oxide acts as an acid acceptor in addition to the effect as a cross-linking agent, and can contribute to corrosion prevention of a mold used for molding.

As the organic peroxide, specifically, di-
t-butyl peroxide, dicumyl peroxide,
t-butylcumyl peroxide, 1.1-t-butylperoxy-3.3.5-trimethylcyclohexane,
2.5-di-methyl-2.5-di (t-butylperoxy) hexane, 2.5-di-methyl-2.5-di (t-
Butylperoxy) hexane-3, bis (t-butylperoxydi-isopropyl) benzene, 2.5-di-methyl-2.5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, t-butylperoxy-2-
Ethyl-hexyl carbonate is mentioned. The compounding amount is preferably 0.2 to 100 parts by mass of the rubber component.
5 to 1 part by mass. When the amount is less than 0.25 parts by mass, the effect of suppressing adhesion and abrasion is low because the crosslinking with the organic peroxide is not sufficiently performed. Extremely low.

The present invention is characterized in that a metal salt of an α, β-unsaturated fatty acid, which is a co-crosslinking agent, is blended in addition to the above-mentioned crosslinking agent. α, β-unsaturated fatty acid metal salt is α, β-
An unsaturated fatty acid is reacted with a metal oxide. Examples of the α, β-unsaturated fatty acid include α, β such as methacrylic acid, acrylic acid, itaconic acid and crotonic acid.
-Monoethylenically unsaturated carboxylic acids can be exemplified, as metal salts zinc, magnesium, sodium, lithium,
Examples thereof include divalent metal salts such as aluminum. The amount of the α, β-unsaturated fatty acid metal salt is preferably 1 to 25 parts by mass with respect to 100 parts by mass of the rubber. 1
If the amount is less than 25 parts by mass, the effect of crosslinking by the α, β-unsaturated fatty acid metal salt is not sufficient. If the amount exceeds 25 parts by mass, workability is poor, and mechanical properties such as dynamic fatigue and flex fatigue due to excessive crosslinking. Is seen to decrease.

In order to increase the crosslinking efficiency, for example, a thiazole-based, thiuram-based, or sulfenamide-based vulcanization accelerator can be blended. Specific examples of the thiazole vulcanization accelerator include 2-mercaptobenzothiazole,
There are 2-mercaptothiazoline, dibendthiazyl disulfide, zinc salt of 2-mercaptobenzothiazole and the like. Specific examples of the thiuram-based vulcanization accelerator include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide. , N, N'-dimethyl-N, N'-diphenylthiuram disulfide and the like, and specific examples of sulfenamide vulcanization accelerators include N-cyclohexyl-2.
-Benzothiazylsulfenamide, N, N'-cyclohexyl-2-benzothiazylsulfenamide and the like. Also, as other vulcanization accelerators, bismaleimide,
Ethylenethiourea can also be used. These vulcanization accelerators may be used alone or in combination of two or more.

As the filler, inorganic fillers such as silica, clay and calcium carbonate, and carbon black, resin,
There are organic fillers such as cork powder.

As the short fibers, organic fibers such as polyester, polyamide, aramid, vinylon, and cotton are used. Preferably, the length is 1 to 10 mm, and the addition amount is 1 to 40 parts by weight based on 100 parts by weight of the rubber. The short fibers are added to the compressed rubber layer 4 to improve the lateral pressure resistance, and the short fibers protrude from the surface of the compressed rubber layer 4 which is in contact with the pulley. And reduce noise during belt running. Of these staple fibers, aramid staple fibers having rigidity, strength and abrasion resistance are most effective.
In addition, when the direction of the short fibers in the rubber layer is 90 ° that is perpendicular to the longitudinal direction of the belt, most of the short fibers are oriented in the range of 70 ° to 110 °. It is desirable.

Examples of the softener and plasticizer include mineral oil, vegetable oil, synthetic softener, and synthetic plasticizer. Specifically, for example, dibutyl phthalate (DBP),
Phthalates such as dioctyl phthalate (DOP), adipates such as dioctyl adipate (DOA), sebacates such as dioctyl sebacate (DOS), and phosphates such as tricresyl phosphate are exemplified. One or more of these can be used.

Rubber is a viscoelastic material, and when energy is applied by deformation, a part is stored as elastic energy and a part is dissipated as heat as viscous energy. The mobility of rubber can be estimated from the elastic energy and the viscous energy. In the present invention, it is preferable to consider parameters relating to the physical properties in order to prevent sticking and abrasion. E ′ and tan δ described below are both parameters related to the viscoelasticity of the rubber, and E ′ is called storage elastic modulus and represents the easiness of storing mechanical energy applied to the rubber composition. It is. Further, tan δ is a coefficient related to a loss elastic modulus called a loss coefficient, and indicates easiness of dissipating mechanical energy applied to the rubber composition as heat. In other words, it is considered that the higher the E 'and the lower the tan δ, the less the occurrence of adhesive wear.

The above measurement is preferably carried out at a temperature at which the rubber is in the plateau region. The plateau region is referred to as a rubber-like region, in which microbrown motion of the main chain becomes active and is in a state of movement close to a liquid that can take various molecular forms, and a parameter relating to the molecular mobility of rubber is set. This is an area where it is easy to evaluate accurately. Although the value varies depending on the compounding and the like, it is generally 70 to 200 ° C. for chloroprene rubber,
50 ° C. is used as the measurement reference temperature.

On the other hand, the same type of rubber as the compressed rubber layer 4 can be used for the adhesive rubber layer 2. In addition, as the main rubber, natural rubber, polyisoprene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber, ethylene-
Ethylene-α-olefin copolymer rubber such as propylene rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR) to which an unsaturated carboxylic acid metal salt is added, alkylated chlorosulfonated polyethylene ( ACSM), chlorosulfonated polyethylene rubber (CSM), etc. as a main component, and a reinforcing agent such as carbon black, a filler, a softening agent, an antioxidant, a vulcanization aid, sulfur or an organic peroxide. A rubber composition to which a suitable vulcanizing agent or the like is added and mixed may be used. It is preferable that short fibers are not mixed in the composition.

The method of mixing the above components is not limited to, for example, a Banbury mixer, a roll, a kneader, an extruder, etc., and can be kneaded by a known means and method as appropriate.

An example of a method for manufacturing the V-ribbed belt 1 is as follows. First, 1 to 1 on the peripheral surface of the cylindrical forming drum
After winding a plurality of base cloths with rubber and an adhesive rubber layer, a cord made of cord is spirally spun thereon, and a compressed rubber layer is sequentially wound thereon to obtain a laminate. Vulcanize to a vulcanized sleeve. The vulcanization method is not limited, and vulcanization is performed by a known means using a vulcanization device such as a mold heating, a hot air heating, a rotary drum vulcanizer, and an injection molding machine.

Next, the vulcanization sleeve is hung between a driving roll and a driven roll, and is run under a predetermined tension. Further, the rotated grinding wheel is moved so as to abut the running vulcanization sleeve to perform vulcanization. 3 to 100 on the surface of the compression rubber layer of the sleeve
The plurality of groove portions are ground at one time. The vulcanized sleeve obtained in this manner is removed from the drive roll and the driven roll, and the vulcanized sleeve is hung on another drive roll and the driven roll to travel, cut to a predetermined width by a cutter, and individually cut. Finish with a V-ribbed belt.

The V-ribbed belt is an embodiment of the present invention and is not limited to this. For example, a V-belt 6 is shown in FIG. 2 as another example of the power transmission belt according to the present invention. The V-belt 6 has a cord 11 embedded in the adhesive rubber layer 9 along the longitudinal direction of the belt, and has an extended rubber layer 7 and a compressed rubber layer 10 adjacent to the upper and lower portions of the adhesive rubber layer 9. . The stretched rubber layer 7 has a structure in which a base fabric 8 is laminated on the surface. The compressed rubber layer 10
The cogs may be provided at predetermined intervals along the longitudinal direction. The flat belt is also a belt that transmits power by friction and is included in the technical scope of the present invention.

[0036]

The present invention will be described in more detail with reference to the following examples. Examples 1 to 5 and Comparative Examples 1 to 3 The components shown in Table 1 were kneaded with a Banbury mixer, and were tightly milled three times with an open roll.
Vulcanized at ° C for 30 minutes. About the obtained vulcanized rubber,
Dynamic viscoelasticity was measured using a DMS measurement module 210 (manufactured by Seiko Instruments Inc.). Length 40
A vulcanized rubber sample having a thickness of 5 mm, a width of 5 mm and a thickness of 2 mm was prepared,
The applied strain is given in a direction perpendicular to the orientation direction of the short fibers,
E ′ and tan δ were measured under the measurement conditions of a temperature of 150 ° C., an amplitude of 10 μm, and a frequency of 10 Hz. The results are also shown in Table 1.

Next, various physical properties of the obtained vulcanized rubber were examined. As a swelling test, the volume swelling ratio of each sample was measured. First, the vulcanized rubber sheet is 10 mm x 5 mm
After cutting into small pieces of × 2 mm and immersing in toluene for 3 days for equilibrium swelling, the weight and specific gravity of the sample were measured to calculate the volume swelling ratio.

As the tensile test, JIS K6251 was used.
According to (sample shape JIS No. 3 dumbbell), the tensile strength and the elongation at break were measured at a tensile speed of 500 mm / min. In addition, a cylindrical vulcanized rubber test piece was prepared and JIS
A compression strain test was performed according to K6262, and a compression strain rate was measured. The results are also shown in Table 1.

A V-ribbed belt using the rubber composition having the composition shown in Table 1 was produced. After wrapping a single ply of rubberized canvas in which a chloroprene rubber composition has been frictionally wound on a plain woven fabric in which a warp and a weft are made of cotton yarn, a cylindrical mold,
An adhesive rubber sheet made of a chloroprene rubber composition was wound, and a cord (1,100 d 2 × 3) made of polyester fiber was spun thereon, and Table 1
Was wound around a compressed rubber layer made of the rubber composition shown in (1) to complete the molding. The obtained molded body was vulcanized by a known method to obtain a cylindrical vulcanized rubber sleeve.

The vulcanized rubber sleeve extracted from the cylindrical mold is mounted on a driving roll and a driven roll of a grinder,
It was rotated after applying tension. 1,6 using a grinding wheel with 150 mesh diamond mounted on the surface
After being rotated at 00 rpm, this is brought into contact with a vulcanization sleeve to polish the 80-rib portion, and then cut into a predetermined width.
1100 V-ribbed belts were produced.

The obtained V-ribbed belt was subjected to a triaxial running test to examine the state of adhesive wear. 3PK1100
V-ribbed belt with a driving pulley having a diameter of 120 mm and a diameter of 12
The belt was mounted on a driven pulley of 0 mm and an idler pulley of 45 mm in diameter, and the driving pulley was rotated at 4,900 rpm and allowed to run for 24 hours. Ambient temperature is room temperature. The results are also shown in Table 1.

[0042]

[Table 1]

As a result, the rubber composition of the example in which an organic peroxide, a metal oxide and aluminum acrylate were blended as a crosslinking agent has a high storage modulus E ′ and a low loss coefficient tan δ, and Also, it was found that the adhesive wear suppressing effect was high in the triaxial running test. In Comparative Examples 3 and 5, it can be seen that it is effective to increase the degree of crosslinking to suppress adhesive wear, but excessive addition of peroxide and excessive addition of aluminum acrylate have an effect on elongation at break and tensile strength. It can be seen that a decrease, that is, a decrease in mechanical properties such as dynamic fatigue resistance and flex fatigue resistance is observed. In Comparative Example 2, although the degree of crosslinking of the rubber composition was relatively high, it did not reach the abrasion suppressing effect of the Examples.

On the other hand, in Comparative Example 1 in which only a metal oxide was blended as a cross-linking agent and in Comparative Example 4 in which a metal oxide and aluminum acrylate were blended, severe abrasion occurred, and addition / non-addition of an organic peroxide was not possible. It is thought to be closely related to the suppression of adhesive wear.

[0045]

As described above, chloroprene rubber is used as the main rubber, metal oxides and organic peroxides, and α, β-
By using a rubber composition containing an unsaturated fatty acid metal salt for at least a part of the rubber member constituting the power transmission belt, it is possible to provide a power transmission belt having an excellent effect of suppressing adhesion and abrasion. A rubber crosslinked composition having a high effect of suppressing abrasion and abrasion and having excellent mechanical properties by adjusting the amount of peroxide and α, β-unsaturated fatty acid metal salt to an appropriate value, and a power transmission belt using the same. Could be provided.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view of a V-ribbed belt according to the present invention.

FIG. 2 is a sectional perspective view of a V-belt according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 V-ribbed belt 2 Adhesive rubber layer 3 Core wire 4 Compressed rubber layer 5 Base cloth

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F16G 5/04 F16G 5/04 5/06 5/06 A 5/20 5/20 A F term (reference) 4J002 AC091 DE076 DE086 DE106 EG028 EG038 EG048 EK037 EK047 EK057 EK087 FA040 FD010 FD150 GM01

Claims (7)

[Claims] 1. A rubber composition comprising a chloroprene rubber as a main rubber, a metal oxide, an organic peroxide and an α, β-unsaturated fatty acid metal salt, comprising at least a rubber member constituting a power transmission belt. A power transmission belt that is partially used. 2. The power transmission belt according to claim 1, wherein 0.25 to 1 part by mass of an organic peroxide is blended with respect to 100 parts by mass of the rubber component. 3. α, β based on 100 parts by mass of the rubber component
The power transmission belt according to claim 1 or 2, wherein the unsaturated fatty acid metal salt is contained in an amount of 1 to 25 parts by mass. 4. The power transmission belt according to claim 1, wherein the metal salt of α, β-unsaturated fatty acid is a metal salt of acrylic acid. 5. The power transmission belt according to claim 4, wherein the metal acrylate is at least one selected from aluminum acrylate and zinc acrylate. 6. The power transmission belt is a V belt composed of an adhesive rubber layer having a core embedded in the belt length direction and a compression rubber layer having a plurality of ribs extending in the belt length direction.
The power transmission belt according to any one of claims 1 to 5, wherein the belt is a ribbed belt, and at least a compression rubber layer is made of the rubber composition. 7. The power transmission belt is a V-belt comprising an adhesive rubber layer having a core buried along a belt length direction and a compression rubber layer, and at least the compression rubber layer is formed of the rubber composition. The power transmission belt according to any one of claims 1 to 5, comprising: