WO2016194371A1

WO2016194371A1 - Transmission belt

Info

Publication number: WO2016194371A1
Application number: PCT/JP2016/002653
Authority: WO
Inventors: 公睦大野; 博之橘
Original assignee: バンドー化学株式会社
Priority date: 2015-06-04
Filing date: 2016-06-01
Publication date: 2016-12-08
Also published as: JPWO2016194371A1

Abstract

A wrapped V belt is provided with a belt body (10) and a reinforcing fabric (15) covering the belt body (10), and is wound on a pulley to transmit power. At least a portion of the belt body (10) is obtained from a rubber composition comprising an ethylene-α-olefin elastomer as a polymer component. An organic peroxide as a cross-linking agent and a co-cross-linking agent that is liquid at ordinary temperature are blended in the rubber composition.

Description

Transmission belt

This disclosure relates to a transmission belt used for agricultural machinery, general industrial machinery, and the like.

In agricultural machines, general industrial machines, etc., transmission belts are widely used to transmit power. Various performances are required for the transmission belt. For example, Patent Document 1 discloses a transmission belt that defines an ethylene content, a diene content, and the like and realizes excellent bending fatigue resistance and heat resistance.

In addition, recycled rubber is used to reduce material costs and manufacturing costs of rubber products. Recycled rubber is made into a state where it can be molded again by subjecting a crosslinked rubber of a used rubber product to chemical treatment or physical treatment. Patent Document 2 discloses a method for producing a recycled rubber in which a crosslinked rubber is subjected to a desulfurization treatment under conditions of a temperature of 180 to 350 ° C. and a shear stress of 10 to 150 kg / cm ² .

JP 2001-82548 A JP-A-9-227724

In addition to various performance requirements for the manufactured transmission belt, workability of the material is required to manufacture the transmission belt. In this regard, the transmission belt of Patent Document 1 has poor processability (tackiness and the like), and excessive air easily enters when the sheet rubber is ply-up during belt molding. Incoming air has a risk of remaining after vulcanization, and as a result, quality stability may not be maintained, and in the case of a wrapped V belt, the belt itself may not be manufactured.

Also, the use of recycled rubber is effective in reducing costs, but desulfurization treatment of vulcanized rubber requires cost, and there is a demand for further cost reduction in this regard.

In view of the above, an object of the present disclosure is to realize a transmission belt excellent in performance such as workability while further reducing costs by reusing rubber.

In order to achieve the above object, a transmission belt according to the present disclosure includes a belt main body and a reinforcing cloth that covers the belt main body, and is a wrapped V-belt that is wound around a pulley and transmits power. A part of the rubber composition includes an ethylene-α-olefin elastomer as a polymer component, and the rubber composition contains an organic peroxide as a crosslinking agent and a co-crosslinking agent that is liquid at room temperature. ing.

The rubber composition may contain vulcanized rubber powder.

According to the above transmission belt, the ply-up property is improved and the mass productivity is improved, and the loss factor tanδ is lowered to improve the transmission capability. This effect becomes more remarkable by blending the rubber composition with vulcanized rubber powder. Further, when the vulcanized rubber powder is used, the rubber can be reused without requiring the cost of the desulfurization treatment, and the cost of the transmission belt can be reduced.

FIG. 1 is a diagram illustrating an example of a transmission belt according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating a method of manufacturing the transmission belt of FIG. FIG. 3 is a diagram illustrating a belt endurance life test method according to an embodiment of the present disclosure. FIG. 4 is a diagram illustrating a method for testing the transmission capability of a belt according to an embodiment of the present disclosure.

Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

FIG. 1 is a view showing an exemplary V-belt B (transmission belt) of the present embodiment. The V belt B is used for, for example, an agricultural machine or an industrial machine. The dimensions of the V-belt B are not particularly limited. For example, the belt circumferential length is 700 to 5000 mm, the belt width is 16 to 17 mm, and the belt thickness is 8 to 10 mm.

The V-belt B includes a belt main body 10 formed of a triple layer of a bottom rubber layer 11 on the belt inner peripheral side (pulley contact side), an intermediate adhesive rubber layer 12 and a back rubber layer 13 on the belt outer peripheral side. Prepare. A core wire 14 is embedded in the adhesive rubber layer 12 so as to form a spiral having a pitch in the belt width direction.

Further, the entire belt body 10 is covered with the reinforcing cloth 15, and the V belt B is a wrapped belt.

The polymer component of the rubber composition constituting the bottom rubber layer 11 includes an ethylene-α-olefin elastomer (EPDM). Further, the rubber composition contains an organic peroxide as a crosslinking agent and a co-crosslinking agent that is liquid at normal temperature. Such an EPDM has improved ply-up properties and improved mass productivity, has a low tan δ, and can suppress heat generation when the belt is bent, so that the belt has excellent bending fatigue.

Further, the rubber composition may contain a vulcanized rubber powder. As a result, the effect of improving the pliability and reducing the tan δ becomes more remarkable. Moreover, since the vulcanized rubber is reused without requiring desulfurization treatment, it contributes to cost reduction.

The vulcanized rubber powder is, for example, sulfur-crosslinked EPDM powder, and the particle size is preferably 1 μm or more, more preferably 20 μm or more, and preferably 1000 μm or less, more preferably 300 μm or less.

Here, the vulcanized rubber powder is agglomerated and has the above dimensions as an agglomerate before mixing. However, the agglomerates are reduced by mixing and kneading with virgin rubber. For example, the particle size is preferably 0.1 μm or more, more preferably 1 μm or more, and preferably 300 μm or less, more preferably 200 μm or less. Become.

Further, the vulcanized rubber powder is, for example, a powder obtained by pulverizing a crosslinked rubber containing sulfur-crosslinked EPDM. Further, rubber powder generated when cutting the crosslinked rubber during the manufacturing process of the transmission belt or the like can be used. In this case, the rubber powder that becomes waste can be reused, leading to cost reduction.

Further, the adhesive rubber layer 12 can also be made of the above rubber composition. Furthermore, at least one surface of the reinforcing cloth 15 may be covered with the rubber composition.

Here, the belt outer surface side of the reinforcing cloth 15 may not be covered with the rubber composition. In this way, the belt is a clean belt that does not contaminate the machine and its surroundings without significantly degrading the performance as compared with the case where the both sides of the reinforcing cloth 15 are coated.

The rubber composition comprises a polymer component and a reinforcing material such as carbon black blended therein, a crosslinking agent, a co-crosslinking agent, a vulcanization accelerator, a vulcanization acceleration aid, an antiaging agent, a softening agent, and the like. .

As a reinforcing material, for example, carbon black, channel black; furnace black such as SAF, ISAF, N-339, HAF, N-351, MAF, FEF, SRF, GPF, ECF, N-234; FT, MT, etc. Thermal black; acetylene black. Silica is also mentioned as a reinforcing agent. The reinforcing agent may be composed of a single species or a plurality of species. The reinforcing material preferably has a blending amount of 30 to 80 parts by mass with respect to 100 parts by mass of the rubber component, from the viewpoint of achieving a good balance between wear resistance and bending resistance.

As the crosslinking agent, an organic peroxide is used, and the blending amount with respect to 100 parts by mass of the rubber component is, for example, 0.5 to 8 parts by mass. Specific examples include dialkyl peroxides such as dicumyl peroxide, peroxyesters such as t-butyl peroxyacetate, and ketone peroxides such as dicyclohexanone peroxide. The organic peroxide may be a single species or a plurality of species.

As a co-crosslinking agent when an organic peroxide is used as a cross-linking agent, a co-crosslinking agent that is liquid at normal temperature is used, and the compounding amount is, for example, 1 to 23 parts by mass, more preferably 2 to 20 parts per 100 parts by mass of the rubber component. Part by mass. For example, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, triallyl isocyanurate, and the like.

Examples of the vulcanization accelerator include sulfenamide-based (for example, CZ) and dithiocarbamate-based (for example, BZ-P). The vulcanization accelerator may be composed of a single species or a plurality of species.

However, a sulfur-crosslinked rubber composition may be used for a part of the belt body 10. When sulfur is used as a crosslinking agent, the blending amount with respect to 100 parts by mass of the rubber component is preferably 0.5 to 4.0 parts by mass. When sulfur is used as a crosslinking agent, it is desirable to use a thiazole (for example, MBT, MBTS, etc.) or thiuram (for example, TT, TRA, etc.) vulcanization accelerator in combination as a vulcanization accelerator. The content of the vulcanization accelerator is, for example, 0.5 to 10 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

Examples of the vulcanization acceleration aid include metal oxides such as magnesium oxide and zinc oxide (zinc white), fatty acids such as metal carbonates and stearic acid, and derivatives thereof. The vulcanization acceleration aid may be composed of a single species or a plurality of species. The amount of the vulcanization acceleration aid is, for example, 0.5 to 8 parts by mass relative to 100 parts by mass of the rubber component.

Antiaging agents include amine-based, quinoline-based, hydroquinone derivatives, phenol-based and phosphite-based agents. The anti-aging agent may be composed of a single species or a plurality of species. The anti-aging agent is, for example, 0 to 8 parts by mass with respect to 100 parts by mass of the rubber component.

Examples of the softener include petroleum softeners, mineral oil softeners such as paraffin wax, castor oil, cottonseed oil, sesame oil, rapeseed oil, soybean oil, palm oil, palm oil, fallen raw oil, waxy wax, rosin And vegetable oil-based softeners such as pine oil. The softener may be composed of a single species or a plurality of species. The amount of the softener other than the petroleum-based softener is, for example, 2 to 30 parts by mass with respect to 100 parts by mass of the rubber component.

In addition, layered silicates such as smectite group, vermiculite group, kaolin group and the like may be included as a compounding agent.

Further, the rubber covering the reinforcing cloth 15 may contain a friction coefficient reducing material. Examples of the friction coefficient reducing material include short fibers such as nylon short fibers, vinylon short fibers, aramid short fibers, polyester short fibers, cotton short fibers, and ultrahigh molecular weight polyethylene resins.

Next, the adhesive rubber layer 12 and the back rubber layer 13 are formed in a band shape having a horizontally long cross section. The adhesive rubber layer 12 and the back rubber layer 13 are formed of a rubber composition obtained by heating and pressurizing an uncrosslinked rubber composition in which various compounding agents are blended into a rubber component and then kneading and crosslinking with a crosslinking agent. .

The rubber component of the rubber composition forming the adhesive rubber layer 12 and the back rubber layer 13 may be the same EPDM as the bottom rubber layer 11. However, other rubber compositions can be used, such as ethylene-α-olefin elastomer, chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), hydrogenated acrylonitrile rubber (H-NBR), and the like. Can be mentioned.

Examples of the compounding agent include a reinforcing material such as carbon black, a vulcanization accelerator, a crosslinking agent, an anti-aging agent, a softening agent and the like, as in the bottom rubber layer 11.

Further, the core wire 14 is composed of twisted yarns such as polyester fiber (PET), polyethylene naphthalate fiber (PEN), aramid fiber, and vinylon fiber. In order to give the core wire 14 adhesion to the belt main body 10, an adhesive treatment for heating after being immersed in an RFL aqueous solution before molding and / or an adhesive treatment for drying after being immersed in rubber paste is performed.

Further, the reinforcing cloth 15 is constituted by, for example, a woven fabric, a knitted fabric, a non-woven fabric or the like formed of yarns such as cotton, polyamide fiber, polyester fiber, and aramid fiber. In order to provide the adhesiveness to the belt main body 10, the reinforcing cloth 15 is coated with rubber paste on the surface on the side of the belt main body 10 and / or an adhesive treatment in which it is immersed in an RFL aqueous solution and heated before molding. An adhesion treatment for drying may be performed.

(Production method of transmission belt)
Hereinafter, a method for manufacturing the V belt B, which is a wrapped V belt, will be described with reference to FIGS. 2 (a) to 2 (g).

First, each rubber sheet 22 for the compression rubber layer, the adhesive rubber layer, and the stretch rubber layer is prepared. This is obtained by processing the uncrosslinked rubber composition described in the embodiment into a sheet shape using a calender roll or the like. Further, the twisted yarn 14 for the core wire and the fabric 15 for the reinforcing fabric are subjected to adhesion treatment.

Next, as shown in FIG. 2A, a rubber sheet 22 such as a chloroprene rubber composition for a compressed rubber layer is wound around a mantle 21 a plurality of times, and a rubber sheet 22 for an adhesive rubber layer is wound thereon. . Furthermore, as shown in FIG. 2 (b), a core wire 14 such as a polyester cord to which an adhesive is attached is spirally wound. Further, as shown in FIG. 2C, the rubber sheet 22 for the adhesive rubber layer and the back rubber layer is wound to produce the cylindrical laminated structure 20.

Next, as shown in FIG. 2 (d), the cylindrical laminated structure 20 is cut into a predetermined width on the mantle 21 and then removed from the mantle 21.

Next, as shown in FIG. 2 (e), the annular laminated structure 20 is wound between a pair of pulleys with the rubber layer on the outer side, and both edges are cut obliquely while rotating to form a V shape. To skiving. This adjusts the volume.

Subsequently, as shown in FIG. 2 (f), lapping is performed with a belt forming cloth 25 that becomes the reinforcing cloth 15 so as to wrap the outer periphery of the annular laminated structure 20 skived into a V shape.

Then, as shown in FIG. 2 (g), the lapped annular laminated structure 20 is externally fitted to a cylindrical mold 23, and the entire cylindrical mold 23 is placed in a vulcanizing can and heated and pressurized. At this time, the rubber component of the annular laminated structure 20 is cross-linked and integrated, whereby the belt forming cloth 25 becomes the reinforcing cloth 15 and the V belt B which is a wrapped V belt is manufactured.

Hereinafter, the wrapped V-belt of the embodiment will be described. Here, rubber compositions A to H containing vulcanized rubber powder were prepared for use as the bottom rubber layer 11. Also, wrapped V-belts of Examples 1 to 4 and Comparative Examples 1 to 4 were prepared using these rubber compositions. Furthermore, as Comparative Example 5, a conventional wrapped V belt made of chloroprene was prepared.

(Rubber composition)
Table 1 shows the compositions of the rubber compositions A to H used for forming the wrapped V-belt bodies of Examples and Comparative Examples.

<Rubber composition A>
As the rubber component, 100 parts by mass of EPDM (manufactured by JSR Corporation, EP33) and 60 parts by mass of vulcanized rubber powder containing 50% by mass of EPDM are used.

On the other hand, as a compounding agent, 50 parts by mass of HAF carbon black (manufactured by Tokai Carbon Co., Ltd., trade name: SEAST 3), 1 part by mass of stearic acid (manufactured by NOF Corporation, beads stearate Tsubaki), zinc oxide (酸化5 parts by weight of chemical industry, zinc oxide (3 types), 10 parts by weight of resin component (manufactured by Nippon Zeon, Quinton A100), 20 parts by weight of oil (Diana Process PW-90, manufactured by Idemitsu Kosan Co., Ltd.) Organic peroxide (trade name: Perbutyl P-40, purity 40% by mass) 5 parts by weight (active ingredient 2 parts by mass), co-crosslinking agent (manufactured by Sanshin Chemical Industry Co., Ltd., trade name: 5 parts by mass of sun ester TMP) was blended and kneaded to obtain rubber composition A shown in Table 4.

Note that the organic peroxide used here is liquid at room temperature.

Further, the vulcanized rubber powder of this example is a rubber powder produced when cutting the crosslinked rubber during the production process of the transmission belt, and the particle size thereof is about 10 μm to 500 μm. After kneading, the aggregate becomes finer and the particle size becomes about 1 μm to 200 μm.

<Rubber composition B>
In the formulation of the rubber composition A, only the co-crosslinking agent was reduced to 2 parts by mass (relative to 5 parts by mass in the rubber composition A) and kneaded to obtain a rubber composition B shown in Table 1. .

<Rubber composition C>
In the formulation of rubber composition A, only the co-crosslinking agent was increased to 20 parts by mass (relative to 5 parts by mass in rubber composition A) and kneaded to obtain rubber composition C in Table 1. .

<Rubber composition D>
In the blending of the rubber composition A, the blended amount of the vulcanized rubber powder was set to 0 (that is, not blended) and kneaded to obtain a rubber composition D shown in Table 1.

<Rubber composition E>
In the blending of the rubber composition A, the blending amount of the co-crosslinking agent was reduced to 0 part by mass (that is, the co-crosslinking agent was not blended), and this was kneaded to obtain the rubber composition E shown in Table 1.

<Rubber composition F>
In the blending of the rubber composition A, only the co-crosslinking agent was blended to 25 parts by mass (relative to 5 parts by mass in the rubber composition A) and kneaded to obtain the rubber composition F shown in Table 1. .

<Rubber composition G>
In the blending of the rubber composition A, 5 parts by mass of zinc dimethacrylate (trade name: Actor ZMA, manufactured by Kawaguchi Chemical Industry Co., Ltd.) was blended as a co-crosslinking agent in place of the sun ester TMP. This was kneaded to obtain a rubber composition G shown in Table 1.

In addition, zinc dimethacrylate is solid (powder) at room temperature.

<Rubber composition H>
In the formulation of the rubber composition A, the crosslinking system was changed to sulfur. Specifically, in place of the organic peroxide and the co-crosslinking agent, 3 parts by mass of sulfur (manufactured by Karuizawa Smelter Co., Ltd., oil-treated sulfur) is used as a thiuram vulcanization accelerator in the same manner as the rubber composition A. 2 parts by mass of accelerator 1 (manufactured by Ouchi Shinsei Co., Ltd., Noxeller TET) and 1 part by mass of accelerator 2 (manufactured by Ouchi Shinsei Co., Ltd., DM-P) which is a thiazole vulcanization accelerator were blended. This was kneaded to obtain a rubber composition H shown in Table 1.

(Loss factor tan δ)
About the uncrosslinked rubber composition of each Example and Comparative Example, a sheet-like rubber sheet was molded and vulcanized, and based on JIS K6394, the vibration frequency was set to 10 Hz and the dynamic strain was set to 1.0%. The loss coefficient tan δ was determined.

(Production of wrapped V-belt)
As the bottom rubber layer 11, any one of the rubber compositions A to H as shown in Table 2 was used, and as shown in FIGS. 2 (a) to (f), Examples 1 to 4 and Comparative Examples 1 to 4 were used. Four wrapped V-belts were made. As the adhesive rubber layer 12 and the friction rubber, rubber compositions prepared in the same manner as the rubber composition of the bottom rubber layer 12 except that vulcanized rubber powder was not blended were used for each belt. As described above, Comparative Example 5 is a conventional wrapped V-belt using chloroprene rubber. In each case, the reinforcing cloth 15 is coated on both sides with the friction rubber.

<Belt test evaluation>
(Belt durability test)
FIG. 3 shows a pulley layout for test evaluation of a belt having a driving pulley 31 having a pulley diameter of 80 mm and a driven pulley 32 having a pulley diameter of 80 mm provided therebelow. Belts to be evaluated were wound around these pulleys, a dead weight of 80 kg was given to the driven pulley 32, and the pulleys were rotated at 3500 rpm with no load.

For the wrapped V belts of Examples 1 to 3 and Comparative Examples 1 to 6, when the belt is run as described above, cracks occur in the bottom rubber layer 11 (failure mode “bottom rubber crack”) or a certain amount of wear occurs. The time until the occurrence (failure mode “high wear”) was measured as a life, and the life of Comparative Example 5 (chloroprene belt) is taken as 100 and is shown in Table 2.

(Belt transmission ability test)
FIG. 4 shows a pulley layout for evaluating the transmission capability of a belt having a driving pulley 41 having a pulley diameter of 100 mm and a driven pulley 42 having a pulley diameter of 100 mm provided on the side thereof. The driven rib pulley 42 is movably provided to the left and right so that an axial load (dead weight DW) can be applied to apply tension to the V-ribbed belt B. Belts to be evaluated were wound around these pulleys, a dead weight of 1078 N (110 kgf) was applied to the driven pulley 42, a rotational load of 2 kw was applied, and the driving pulley 41 was rotated at 1800 rpm. The slip ratio was measured for each belt, and the value of Comparative Example 5 (chloroprene belt) is set to 1 and shown in Table 2.

Further, the ply-up property and loss factor tan δ (value at 100 ° C.) for the bottom rubber are also shown in Table 2, respectively.

In addition, when the friction processing is performed with a calendar, the canvas is passed in a state where rubber is wound around one roll, and the part of the wound rubber is adhered to the canvas so as to be rubbed. The workability related to this is called friction workability, and when the friction workability is poor, all of the wound rubber is transferred to the canvas and becomes a top processed state.

Also, when joining bias-cut canvases, wrap them several millimeters, and joint them together with the adhesive strength of the friction rubber. The workability related to this is called lap joint workability. If the lap joint workability is poor, joints cannot be made, or even if joints can be made once, problems such as partial peeling before winding will occur. .

Also, at the time of lapping shown in FIG. 2 (f), the wrapped canvas should not be peeled off by the adhesive force of the canvas itself. This processability is called covering processability, and when the covering processability is poor, problems such as peeling off of the canvas occur.

Also, the adhesiveness at the time of winding in FIG. 2 (a) is called ply-up property. If the ply-up property is poor, it may be peeled off at the time of FIG. 2 (a), or even if there is no problem at the time of FIG. 2 (a), a subsequent process such as FIG. 2 (d), FIG. Causes problems such as peeling off.

(Evaluation results)
Table 2 shows the evaluation results of the bottom rubber and the belt.

Each of the wrapped V-belts of Examples 1 to 4 in which the crosslinking system is an organic peroxide and the co-crosslinking agent is TMP that is liquid at room temperature (the blending amounts are 5, 2, and 20 parts by mass in order) is all ply-up property. Is good. On the other hand, the comparative example 4 in which the crosslinking system is sulfur and the comparative example 3 in which the crosslinking system is an organic peroxide but the co-crosslinking agent is solid zinc dimethacrylate at room temperature have a ply-up property. bad. Moreover, although the crosslinking system is an organic peroxide, the ply-up property is also poor in the case of Comparative Example 1 in which no co-crosslinking agent is used.

Furthermore, the ply-up property is also poor for Comparative Example 2 in which the crosslinking system is an organic peroxide and the co-crosslinking agent is TMP. In the case of the comparative example 2, it is 25 mass parts of the compounding quantity of a co-crosslinking agent, and since this is too much, it is thought that adhesiveness fell because bleeds increased too much. Accordingly, there is an appropriate range for the amount of co-crosslinking agent. For example, it is good to set it as 1 to 23 mass parts with respect to 100 mass parts of rubber components.

Next, the loss coefficient tan δ is 0.179, 0.182, 0.172, and 0.196 in order in Examples 1 to 4. This is lower than 0.215 of Comparative Example 4 in which the crosslinking system is sulfur, and 0.201 of Comparative Example 1 in which the crosslinking system is an organic peroxide but no co-crosslinking agent is used. In Comparative Examples 2 and 3, since tan δ is 0.175 and 0.173, Examples 1 to 3 have tan δ equivalent to these.

Further, regarding the belt transmission capacity (evaluation in which the slip ratio of Comparative Example 11 using chloroprene rubber at the standard transmission capacity was set to 1), Examples 1 to 4 were 0.91, 0.99, 0.96 and 0.98, which is superior to that of chloroprene. Further, it is clearly superior to Comparative Example 1 in which no co-crosslinking agent is used and Comparative Examples 4 and 1.05 and 1.38 in which the crosslinking system is sulfur.

Regarding the durability of the belt, the durability life of Examples 1 to 4 is 331, 359, 223, and 370 in this order, which is remarkably superior to that of Comparative Example 5 using the standard chloroprene rubber. The endurance lives of Comparative Example 1 using EPDM and no co-crosslinking agent, Comparative Example 2 in which the co-crosslinking agent is 25 parts by mass, and Comparative Example 4 in which the cross-linking system is sulfur are 205, 214 and 210 in this order. Against these, Examples 1, 2 and 4 are clearly superior.

As described above, Comparative Examples 1 to 4 have excellent parts in terms of tan δ, transmission capability, and durability test life, but all of them are low in mass productivity due to poor ply-up properties. On the other hand, Examples 1 to 4 have the same or better performance as each comparative example with respect to tan δ, transmission capability, and durability test life, and good ply-up properties. In Comparative Example 5 using chloroprene rubber, tan δ and ply-up properties are good, but the durability test life is 100 on the basis, and Examples 1 to 4 have performances that are two to three times as much as this. have.

In this way, a rubber composition that is comprehensively superior in terms of tan δ, transmission capability, durability test life, and ply-up properties by using an organic peroxide as a crosslinking system and using an appropriate amount of a co-crosslinking agent that is liquid at room temperature. You can get things. Further, since the vulcanized rubber powder can be reused without performing a desulfurization treatment, a transmission belt can be manufactured at a lower cost.

It should be noted that the tan δ is clearly more apparent in Examples 1 to 3 made of a rubber composition using vulcanized rubber powder than in the belt of Example 4 made of a rubber composition not using vulcanized rubber powder. Are better. The transmission capacity and durability are almost the same.

The wrapped V-belt of the present disclosure has high wear resistance and workability, and thus is useful as a transmission belt for use in various general industrial machines. Moreover, cost reduction can be achieved by using vulcanized rubber as a part of the material.

DESCRIPTION OF SYMBOLS 10 Belt main body 11 Bottom rubber layer 12 Adhesive rubber layer 13 Back rubber layer 14 Core wire 15 Reinforcement cloth 20 Laminated structure 21 Mantle 22 Rubber sheet 23 Cylindrical mold 25 Belt forming cloth 31 Driving pulley 32 Driven pulley

Claims

In a wrapped V-belt that includes a belt body and a reinforcing cloth that covers the belt body, and is wound around a pulley to transmit power,
At least a part of the belt body is composed of a rubber composition containing an ethylene-α-olefin elastomer as a polymer component,
A transmission belt in which an organic peroxide as a crosslinking agent and a co-crosslinking agent that is liquid at room temperature are blended in the rubber composition.
The power transmission belt according to claim 1,
A transmission belt characterized in that vulcanized rubber powder is blended in the rubber composition.
The power transmission belt according to claim 2,
The transmission belt, wherein the vulcanized rubber powder forms an aggregate, and the particle size of the aggregate is 0.1 μm or more and 300 μm.
The transmission belt according to any one of claims 1 to 3,
The transmission belt, wherein the co-crosslinking agent is blended in an amount of 1 to 23 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.
The transmission belt according to any one of claims 1 to 4,
The power transmission belt, wherein the co-crosslinking agent is at least one of trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, and triallyl isocyanurate.
In the transmission belt according to any one of claims 1 to 5,
The power transmission belt according to claim 1, wherein at least a surface of the reinforcing cloth on the belt body side is covered with the rubber composition.