JP2003166598A - Transmission belt and rubber composition therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission belt having excellent heat resistance and cold resistance and improved adhesion wear resistance to enhance the durability of the belt. <P>SOLUTION: The V-ribbed belt 1 constituted of an adhesive rubber 3 in which core wires 2 are embedded along the longitudinal direction of the belt, a compression rubber layer 4 having a plurality of ribs 7 extending to the circumference direction of the belt. At least in the compression rubber layer 4, 0.2-10 pts.wt. of N,N'-m-phenylene dimaraimide is added to 100 pts.wt. of an etylene-α-olefin erastomer and a peroxide vulcanized rubber layer is used. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition and a power transmission belt using the same, and more specifically, to an alkylated chlorosulfonated polyethylene excellent in heat resistance and cold resistance, which causes a problem of adhesive wear and a problem of pronunciation. The present invention relates to a rubber composition for a transmission belt in which the stability of unvulcanized rubber is improved, and a transmission belt related to a friction transmission type such as a cut edge type V belt.

[0002]

2. Description of the Related Art In recent years, the ambient temperature around the engine room of an automobile has risen as compared with the conventional temperature due to the social demand for energy saving and compactness. Along with this, the operating environment temperature of the power transmission belt has also risen. Conventionally, natural rubber, styrene-butadiene rubber, and chloroprene rubber have been mainly used for power transmission belts, but in a high temperature atmosphere, a problem occurs that cracks occur early in the cured compressed rubber layer.

In order to prevent the belt from being damaged early,
Conventionally, improvement of heat resistance of chloroprene rubber has been studied,
Although some improvements have been made, there are limits as long as chloroprene rubber is used, and at present, sufficient effects have not been obtained.

For this reason, the use of rubbers having a highly saturated or completely saturated main chain, such as chlorosulfonated polyethylene rubbers, hydrogenated nitrile rubbers, and fluororubbers, which are excellent in heat resistance, has been studied. . Of these, chlorosulfonated polyethylene is generally equivalent to chloroprene rubber in dynamic fatigue resistance, wear resistance, and oil resistance. However, chlorosulfonated polyethylene has problems in terms of durability and low temperature characteristics (cold resistance), and improvement thereof is desired.

Therefore, in Japanese Patent No. 2614547,
It is described that alkylated chlorosulfonated polyethylene (hereinafter referred to as ACSM) in which an alkyl group is introduced into the main chain of a chlorosulfonated polyethylene molecule to reduce crystallinity is used as a compression rubber for a power transmission belt. There is. That is, this product has a chlorine content of the above ACSM of 15 to 35% by weight and a sulfur content of 0.5 to
By setting the content to 2.5% by weight, the low temperature characteristics of the transmission belt are improved.

Further, in Japanese Patent No. 2983894, it is described that an ACSM in which an alkyl group is introduced into the main chain of a chlorosulfonated polyethylene molecule to reduce the crystallinity is used as a compression rubber for a power transmission belt. . Here, the temperature of ACSM is 100 ° C and the frequency is 10H.
The tan δ (loss tangent) at z is in the range of 0.08 to 0.15 to suppress the generation of cracks.

[0007]

However, this A
When a belt made of CSM is run for a long period of time, there is a problem that the hardness of the surface of the belt in contact with the pulley is lowered and the belt is in an adhesive state and is worn, so-called adhesive wear is caused.

In the case of a transmission belt using ACSM, when it is used as a V-ribbed belt for an air compressor (hereinafter referred to as A / C) of an automobile, this A
At the moment when the / C switch is turned on, a sound is produced by slip. Normally, the A / C is switched off when the room temperature in the automobile is high, the belt and the A / C are not linked, and only the belt idles at high speed.
Therefore, as the room temperature inside the vehicle rises, the moment the A / C switch is turned on, the belt and the A / C start to interlock, but at that time, a sudden load is applied to the belt, and this load causes the belt to I found that I could slip for a moment and pronounce it.

Further, there is a problem that it is a material which is difficult to handle because it is very easy to be vulcanized in an unvulcanized rubber state and has poor stability in storage after blending various compounding agents.

Therefore, the present invention is a transmission belt using alkylated chlorosulphonated polyethylene as a compression rubber layer, which is excellent in heat resistance and cold resistance, and further prevents problems of adhesive wear and pronunciation and causes unvulcanization. An object of the present invention is to provide a power transmission belt and a rubber composition for a power transmission belt, which have improved rubber storage stability.

[0011]

In order to solve the above problems, according to claim 1 of the present invention, an elastic body including an adhesive rubber layer having a core wire embedded along the longitudinal direction of the belt and a compression rubber layer. In a power transmission belt composed of layers, at least the compression rubber layer contains a maleimide co-crosslinking agent in an amount of 1.0 to 100 parts by mass with respect to 100 parts by mass of alkylated chlorosulfonated polyethylene.
5.0 parts by mass, 10 to 20 parts by mass of short fibers, 1 part of plasticizer
It is characterized by containing 0 to 20 parts by mass.

By mixing a predetermined amount of the maleimide-based cross-linking agent with the ACSM in this way, the physical properties such as the modulus of the rubber are improved, and even if the belt is run in a high temperature environment, sticking hardly occurs. It is possible to prevent wear.

According to a second aspect of the present invention, the transmission belt uses a sebacate plasticizer as the plasticizer.

By using a specific type of plasticizer as described above, the stability in storage in unvulcanized rubber can be improved without lowering the heat resistance of the rubber.

In claim 3, 25% or more of all the short fibers are para-aramid short fibers in the transmission belt.

By using a para-aramid fiber in a predetermined amount or more in the short fibers to be blended in ACSM, it is possible to prevent the generation of noise due to slip between the pulley and the pulley while the belt is running.

According to a fourth aspect of the present invention, the transmission belt is a V-ribbed belt including an adhesive rubber in which a core wire is embedded along the longitudinal direction of the belt and a compression rubber layer having a plurality of rib portions extending in the circumferential direction of the belt.

In the rib portion of the V-ribbed belt, problems such as adhesive wear and sounding are likely to occur, and the effect of the present invention can be said to be remarkably obtained.

According to a fifth aspect of the present invention, in a rubber composition for a power transmission belt, which comprises an adhesive rubber layer having a core wire embedded along the longitudinal direction of the belt and an elastic layer containing a compressed rubber layer, at least the compressed rubber layer is alkylated. 1. A maleimide co-crosslinking agent was added to 100 parts by mass of chlorosulphonated polyethylene.
0 to 5.0 parts by mass, 10 to 20 parts by mass of short fibers and 10 to 20 parts by mass of a plasticizer are blended.

By mixing a predetermined amount of a maleimide-based cross-linking agent with ACSM, the physical properties such as the modulus of rubber are improved, and even if the belt is run in a high temperature environment, sticking hardly occurs and sticky wear occurs. Can be prevented.

According to a sixth aspect of the present invention, there is provided a rubber composition for a power transmission belt which uses a sebacate plasticizer as a plasticizer.

By using a specific type of plasticizer as described above, the stability in the unvulcanized rubber can be improved without deteriorating the heat resistance of the rubber, and the unvulcanized rubber after compounding can be long. Since it can be left for a while, it is advantageous in terms of workability in manufacturing the belt.

The rubber composition for a power transmission belt according to claim 1 or 2, wherein 25% or more of the entire short fibers are para-aramid short fibers.

By using a para-aramid fiber in a predetermined amount or more in the short fibers to be mixed with ACSM, it is possible to prevent the generation of noise due to the slip between the pulley and the pulley while the belt is running.

[0025]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the drawings.

FIG. 1 shows a V-ribbed belt for an A / C of an automobile according to an embodiment of the present invention. The V-ribbed belt 1 shown in FIG. 1 has a core wire 3 made of aramid fiber as a material and having a high strength and a low elongation, embedded in an adhesive rubber layer 2, and a compression rubber layer which is an elastic layer below the core wire 3. Have five. The compressed rubber layer 5 is provided with a plurality of rib portions 6 extending in the longitudinal direction of the belt and having a substantially triangular section, and a canvas 4 with rubber attached to the surface of the belt.

The compressed rubber layer 5 has a chlorine content of 15 to 35.
A rubber composition of alkylated chlorosulphonated polyethylene (ACSM) is used in which the weight percentage is preferably 25 to 32 wt% and the sulfur content is in the range of 0.5 to 2.5 wt%.

Since the alkyl side chain of ACSM plays a role of inhibiting the crystal of polyethylene like chlorine, the chlorine content can be reduced to 35% by mass or less without leaving the crystal of polyethylene. As a result, the cohesive force between chlorine is weakened in the low temperature region, and the low temperature resistance is improved. Further, even in a high temperature region, the presence of an alkyl side chain that is more inert than chlorine lowers the reactivity and improves the heat resistance. The chlorine content is required to be 15 to 35% by weight, and if it exceeds 35% by weight, cold resistance and heat resistance are not sufficient. On the other hand, if it is less than 15% by mass, oil resistance and mechanical strength are insufficient. Further, in order to balance oil resistance, heat resistance and cold resistance, the preferable content is 25 to 32% by weight.

The acid acceptor used here is not particularly limited, but a magnesium oxide-aluminum oxide solid solution is preferred, and a specific example thereof is KW-manufactured by Kyowa Chemical Industry Co., Ltd.
2000, KW-2100 and the like.

The acid acceptor is added in an amount of 1 to 50 parts by weight, preferably 4 to 20 parts by weight, based on 100 parts by weight of ACSM. In this case, if the magnesium oxide-aluminum oxide solid solution is less than 1 part by weight, crosslinking will occur. Since it is not possible to sufficiently remove the hydrogen chloride that occurs in the belt, the number of cross-linking points in the ACSM is small, and a predetermined vulcanized product cannot be obtained, and the belt lacks heat resistance and is susceptible to early cracking. On the other hand, when the amount exceeds 50 parts by weight, the Mooney viscosity becomes extremely high, which causes a problem of processing and finishing.

This magnesium oxide-aluminum oxide solid solution may be added as it is during kneading, but it may be treated with an anionic surfactant such as sodium stearate or a silane coupling agent in advance in order to improve the dispersibility. It is also possible to use.

The ACSM rubber composition should be used together with various compounding agents such as carbon black, a plasticizer, an antioxidant, a processing aid, an adhesive, a cross-linking agent, a co-cross-linking agent, and organic or inorganic short fibers. You can There is no particular limitation on the method of mixing these components, and for example, a Banbury mixer, a kneader or the like can be used and kneading can be appropriately performed by a known means and method.

In the present invention, a maleimide co-crosslinking agent is used as the co-crosslinking agent among the above-mentioned compounding agents. And the blending amount is 1.0 to 100 parts by mass of ACSM.
The amount is 5.0 parts by mass, more preferably 1.5 to 3.0 parts by mass. When the amount is less than 1.0 part by mass, the effect of improving the physical properties of rubber is small and the adhesive wear cannot be prevented.
On the other hand, if the amount exceeds 5.0 parts by mass, the elongation of rubber physical properties becomes small and the heat resistant life becomes inferior, which is not preferable.

The maleimide co-crosslinking agent is used because it is superior to the case of using other co-crosslinking agents in that the degree of crosslinking can be increased without adversely affecting the scorch. Specific examples of the maleimide-based co-crosslinking agent include triallyl cyanurate,
Triallyl isocyanurate, trimethylpropane,
There is N, N'-m-phenyldimaleimide.

Examples of plasticizers that can be used next include sebacate plasticizers, polyether plasticizers, adipate plasticizers, phthalate plasticizers and aromatic softeners. Among them, using a sebacate plasticizer can improve the stability of unvulcanized rubber in place without lowering the heat resistance of the rubber composition, and the rubber after compounding can be left for a long period of time. It is preferable because it is excellent in workability when manufacturing the belt. DOS as sebacate plasticizer
(Dioctyl sebacate), DBS (dibutyl sebacate), DMS (dimethyl sebacate), etc. can be mentioned.

The compounding amount is 1 with respect to 100 parts by mass of ACSM.
When the amount is in the range of 0 to 20 parts by mass and the compounding amount is less than 10 parts by mass, tackiness is less likely to occur, but cold resistance is deteriorated, which is not preferable. If it exceeds 20 parts by mass, it may cause adhesion again, which is not preferable.

Examples of the short fibers include nylon fibers, aramid fibers, polyester fibers, cotton and the like, which are short fibers cut into a length of 2 to 6 mm. These short fibers are mixed in the range of 10 to 20 parts by mass with respect to 100 parts by mass of ACSM. In the present invention, it is preferable that 25% or more of the total amount of the short fibers to be mixed be para-aramid short fibers. The official name of the para-aramid fiber is polyparaphenylene terephthalamide, and specific examples of products include Toaron and Kevlar (trade name). Also, the monofilament has a length of 2 to 6 mm,
The diameter is about 9 to 18 μm.

Since the para-aramid fiber has higher rigidity and strength than the meta-aramid fiber, the rib which is the contact surface with the pulley when used in the compressed rubber layer of the belt in the belt width direction is used. Protruding from the surface of the part. Further, since the tip end thereof is fibrillated, the surface of the rib portion is covered with the fibrillated fiber, and it is possible to prevent the sound generation when the belt is running.

When the blending amount of the short fibers is less than 10 parts by mass, the effect of reinforcing the compressed rubber layer of the belt is reduced. If the amount of para-aramid fiber is less than 25% with respect to the total amount of short fibers, the amount of protruding fibers will be so small that the pulley contact surface of the belt cannot be sufficiently covered, so the effect of preventing sound generation is weak. Therefore, it is not preferable.

When the amount of the short fibers added is more than 20 parts by mass, cracking is likely to occur in the compressed rubber layer although it is effective in preventing sound emission. Further, in the case of para-aramid fiber, the rigidity is particularly high. Therefore, if the content is too large, peeling occurs at the interface between the short fiber and ACSM, which leads to early cracking in the rubber, which is not preferable.

An example of the method of manufacturing the V-ribbed belt 1 is as follows. First, 1 to the peripheral surface of the cylindrical forming drum
After wrapping a plurality of cover canvas and cushion rubber layer, a core wire made of rope is spirally spun on this, and a compressed rubber layer is further wound in sequence to obtain a laminate,
This is vulcanized to obtain a vulcanized sleeve.

Next, the rib portion 6 is formed on the compressed rubber layer, and it is preferable that the rib portion 6 is formed by polishing molding. For the compressed rubber layer 5 containing short fibers, 80 is formed on the surface of the grinder. A V-ribbed polishing operation is performed using a dry grinder wheel fitted with ~ 200 mesh diamonds.

By polishing using the dry grinder, as shown in FIG. 2, a part of the para-aramid fiber protruding from the side surface of the V-shaped rib portion 6 is fibrillated.
It is in the state of being. The fibrillation 8 that is prominently derived from the para-aramid fiber is a state in which filaments of short fibers protruding from the side surface of the rib portion 6 are torn in the length direction and are subdivided. The length of the projecting portion is 0.5 mm or less, and the thickness of the fibrillated portion 8 is 1/2 to 1/8 of the thickness of the filament embedded in the rib 6. At least a portion of the portion is curled.

For the core wire 3, polyethylene terephthalate fiber, polyester fiber containing ethylene-2,6-naphthalate as a main constituent unit, aromatic polyamide fiber, glass fiber or the like can be used. These core wires 3 are subjected to an adhesive treatment for the purpose of improving adhesiveness with rubber. As such an adhesion treatment, it is general that the fibers are immersed in resorcin-formalin-latex (RFL solution) and then dried by heating to form a uniform adhesive layer on the surface. However, the method is not limited to this, and there is also a method of performing pretreatment with an epoxy or isocyanate compound and then treating with an RFL solution.

Further, the adhesive rubber layer 2 has heat resistance and is a chloroprene rubber composition which adheres well to the polyester fibers, aromatic polyamide fibers, glass fibers and the like which are the core wires 3, and the hydrogenation rate is 80% or more. Hydrogenated nitrile rubber, etc. are used. This is because the main chain of ACSM is polyethylene, the cohesive energy of the polymer is small, and it is difficult to obtain a sufficient adhesive force.

The cover canvas 4 is a cloth woven into a plain weave, a twill weave, a satin weave, etc., using a thread made of cotton, polyamide, polyethylene terephthalate and aramid fiber.

The A / C V-ribbed belt 1 configured as described above is used for the compression rubber layer 5 in the AC.
The SM rubber composition can prevent the curing of the rubber because the cohesive energy of chlorine can be kept low even in a low temperature atmosphere due to the limited range of the chlorine content, and a plasticizer excellent in low temperature characteristics can be obtained. Addition improves the cold resistance of the belt. Furthermore, since the fibrillated para-aramid fiber is projected from the side surface of the rib 6, the contact area becomes large and the friction coefficient becomes high. for that reason,
Slip is less likely to occur even when a belt that is spinning at high speed and has a reduced belt tension is suddenly loaded. Therefore, it is possible to improve the effect of preventing sound generation due to slip.

The power transmission belt according to the present invention is not limited to the A / C V-ribbed belt of an automobile used for a sudden load when the belt tension is lowered, and is not limited to the automobile. It can also be used as a general transmission belt for transmitting other driving force, or as a transmission belt for repeatedly driving and stopping.

As another belt, a cut edge type V
It is also used for the belt 21. As shown in FIG. 2, the belt 21 is composed of an adhesive rubber layer 24 in which a core wire 23 is embedded and a compressed rubber 26. Further, each surface layer of the adhesive rubber layer 24 and the compressed rubber layer 26 has a rubber-coated canvas 22. Are stacked.

[0050]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

(Examples 1 to 3, Comparative Examples 1 to 3) Example 1
As Comparative Examples 1 to 3, the compression rubber layer has ACSM as a main constituent element, and the plasticizer is dioctyl sebacate (DOS) of the sebacate type, and the compounding amount is ACSM100.
Constant 15 parts by weight to 100 parts by weight, 100% short fiber
1 para-aramid fiber to 100 parts by mass of ACSM
A constant amount of 5 parts by mass, N, N'-m-phenylene dimaleimide was used as the maleimide co-crosslinking agent, and the compounding amount was changed between 0.5 and 6.0 parts by mass and thiuram vulcanization. A V-ribbed belt using an accelerator was prepared, and the occurrence of adhesive wear and the generation of sound of the belt were investigated.

Here, in the V-ribbed belt 1, a core wire 3 made of a rope of polyester fiber is embedded in an adhesive rubber layer 2, and one ply of a rubber-coated cotton canvas 4 is laminated on the upper side thereof.
On the other hand, below the adhesive rubber layer 2 is a compressed rubber layer 5, which has four ribs 6 in the belt longitudinal direction. The obtained V-ribbed belt 1 is a K-shaped 4-ribbed belt having a length of 820 mm according to the RMA standard, a rib pitch of 3.56 mm, a rib height of 2.0 mm, a belt thickness of 4.3 mm, and a rib angle of 40.
°.

The adhesive rubber layers each consist of the rubber composition shown in Table 1. Further, the compressed rubber layers were adjusted to have the constitutions shown in Table 2, and after kneading with a Banbury mixer,
What was rolled with a calendar roll was used. The compressed rubber layer contains short fibers and is oriented in the belt width direction. The belt according to this example was manufactured by a conventionally known ordinary method. First, 1-ply rubber-coated cotton canvas was wound around a flat cylindrical mold, and then an adhesive rubber layer was wound around it. After spinning the core wire and installing the compression rubber layer, the vulcanization jacket is inserted on the compression rubber layer. Next, the molding mold is placed in a vulcanization can and the temperature is 150 ° C.
After vulcanizing for 30 minutes, the tubular vulcanized sleeve is taken out of the mold, the compressed rubber layer of the sleeve is molded into ribs by a grinder, and the molded body is cut into individual belts.

Regarding the running condition of the V-ribbed belt, for the adhesion wear test, the V-ribbed belt has a driving pulley (diameter 120 mm), a driven pulley (diameter 120 mm), and an idler pulley (diameter 45 mm) at room temperature in a triaxial layout. Installed on the driven pulley, load 19.2 horsepower on the driven pulley,
Idler pulley mounting load 85kgf, rotation speed 490
After running at 0 for 48 hours, the presence or absence of adhesive wear on the belt surface was examined. Further, a high temperature reverse bending durability test at 120 ° C. was performed. The results are shown in Table 2.

[0055]

[Table 1]

[0056]

[Table 2]

As can be seen from the results in Table 2, Examples 1 to 3 using the maleimide co-crosslinking agent have no problem of adhesion and are excellent in heat resistance, while the thiuram vulcanization accelerator is used. Although Comparative Example 3 used did not have a problem due to adhesion, the heat resistance was inferior to that of Example. In Comparative Example 1 in which the maleimide-based co-crosslinking agent was used in a small amount, adhesive wear occurred and the limit tension for sounding was increased. On the contrary, Comparative Example 2 containing a large amount of the maleimide-based co-crosslinking agent resulted in poor heat resistance.

(Examples 4 to 6 and Comparative Examples 4 and 5) Example 4
-8, the compression rubber layer has ACSM as a main component, and the co-crosslinking agent is N, which is a maleimide-based co-crosslinking agent.
Using N'-m-phenylenedimaleimide, the compounding amount was A
CSM is 100 parts by weight and 2 parts by weight is constant, short fibers are 100% para aramid fibers and ACSM is 100 parts by weight, and 15 parts by weight is constant, and sebacate-based dioctyl sebacate (DOS) is used as a plasticizer. A V-ribbed belt was prepared by changing the blending amount from 5.0 to 25 parts by mass with respect to 100 parts by mass of ACSM, and the occurrence of adhesive wear of the belt and the cold resistance were examined by a low temperature test at -35 ° C. The other conditions were the same as in Example 1 above. The results are shown in Table 3.

[0059]

[Table 3]

From the results of Table 3, Comparative Example 4 is inferior in cold resistance to Examples 5 to 7. Comparative Example 5
Was excellent in cold resistance, but a problem of sticking was confirmed. Therefore, the blending amount of the sebacate plasticizer is ACSM10.
It can be said that the range of 10 to 20 parts by mass is more preferable with respect to 0 parts by mass.

(Examples 7 to 12) In Examples 7 to 12, the compressed rubber layer has ACSM as a main constituent element, and the co-crosslinking agent is N, N'-m which is a maleimide co-crosslinking agent.
-Using phenylene dimaleimide, the blending amount is ACSM1
The content is fixed at 2 parts by mass with respect to 00 parts by mass, and the plasticizer is dioctyl sebacate of the sebacate type, and the compounding amount is AC.
A V-ribbed belt was prepared by blending nylon short fibers, para-aramid fibers and meta-aramid short fibers as shown in Table 4 with a constant short fiber content of 15 parts by mass with respect to 100 parts by mass of SM. The occurrence and pronunciation were investigated. The other conditions were the same as in Example 1 above.
The results are shown in Table 4.

[0062]

[Table 4]

From the results of Table 4, Example 7 is the same as Examples 8-10.
In comparison with the above, the sound output is large, and the sound output of Example 11 is good, but the life is relatively early due to the occurrence of cracks in the rib portion, and the short fiber content is 10 to 20. It is understood that the range of parts by mass is preferable. Further, in Example 12 in which the para-aramid fiber was not used at all as the short fiber and the meta-aramid fiber was used, the limit tension was high, and it is understood that it is more preferable to use the para-aramid fiber.

(Examples 13 to 15) In Examples 13 to 15, the compressed rubber layer had ACSM as a main constituent element, and the co-crosslinking agent was N, N'- which was a maleimide co-crosslinking agent.
Blending amount is ACSM using m-phenylene dimaleimide
It is constant at 2 parts by mass with respect to 100 parts by mass, and the short fiber is 1
The amount of the 00% para aramid fiber was fixed to 15 parts by mass with respect to 100 parts by mass of ACSM, and the plasticizer was Example 13 using dioctyl sebacate of the sebacate type, Example 14 using dioctyl adipate of the adipate type, and the ether type. Example 3 using the ether thioether of Example 1 and 3 types of rubber compositions in which the compounding amount was fixed to 15 parts by mass with respect to 100 parts by mass of ACSM, the standing stability of the belt was evaluated. The results are shown in Table 5.

[0065]

[Table 5]

As can be seen from the results in Table 5, among the kinds of plasticizers, Example 13 using the sebacate plasticizer is superior in heat resistance to that using the adipate plasticizer, and the ether plasticizer. It can be seen that the unvulcanized rubber is superior in stability in-place as compared with the one using the agent.

[0067]

As described above, according to the first aspect of the present invention, in the transmission belt including the adhesive rubber layer having the core wire embedded along the longitudinal direction of the belt and the elastic layer including the compression rubber layer,
At least in the compressed rubber layer, 1.0 to 5.0 parts by mass of a maleimide-based co-crosslinking agent, 10 to 20 parts by mass of short fibers, and 10 to 20 parts by mass of a plasticizer with respect to 100 parts by mass of alkylated chlorosulphonated polyethylene. It is characterized by being mixed in parts.

By mixing the maleimide cross-linking agent with ACSM in a predetermined amount in this manner, the physical properties such as the modulus of the rubber are improved, and the tack is less likely to occur even when the belt runs in a high temperature environment. It is possible to prevent wear.

According to a second aspect of the present invention, the power transmission belt uses a sebacate plasticizer as the plasticizer.

By using a specific type of plasticizer as described above, the stability of the unvulcanized rubber can be improved without deteriorating the heat resistance of the rubber.

In claim 3, 25% or more of all the short fibers are para-aramid short fibers in the transmission belt.

By using a para-aramid fiber in a predetermined amount or more in the short fibers to be blended in ACSM, it is possible to prevent the generation of noise due to slippage with the pulley during running of the belt.

According to a fourth aspect of the present invention, the transmission belt is a V-ribbed belt including an adhesive rubber having cores embedded along the longitudinal direction of the belt and a compression rubber layer having a plurality of ribs extending in the circumferential direction of the belt.

In the rib portion of the V-ribbed belt, problems such as adhesive wear and pronunciation are likely to occur, and it can be said that the effects of the present invention can be remarkably obtained.

According to a fifth aspect of the present invention, in a rubber composition for a power transmission belt, which comprises an adhesive rubber layer having a core wire embedded along the longitudinal direction of the belt and an elastic layer containing a compressed rubber layer, at least the compressed rubber layer is alkylated. 1. A maleimide co-crosslinking agent was added to 100 parts by mass of chlorosulphonated polyethylene.
0 to 5.0 parts by mass, 10 to 20 parts by mass of short fibers and 10 to 20 parts by mass of a plasticizer are blended.

By mixing a predetermined amount of a maleimide-based crosslinking agent with ACSM, the physical properties such as the modulus of rubber are improved, and even if the belt runs in a high temperature environment, adhesion is less likely to occur and adhesion wear occurs. Can be prevented.

In a sixth aspect, the rubber composition for a power transmission belt uses a sebacate-based plasticizer as the plasticizer.

By using a specific type of plasticizer as described above, the stability in storage in the unvulcanized rubber can be improved without deteriorating the heat resistance of the rubber, and the unvulcanized rubber after compounding can be long. Since it can be left for a while, it is advantageous in terms of workability in manufacturing the belt.

In the seventh aspect, the rubber composition for a power transmission belt according to the first or second aspect, wherein 25% or more of the whole short fibers are para-aramid short fibers.

By using a para-aramid fiber in a predetermined amount or more in the short fibers to be mixed with ACSM, it is possible to prevent the generation of noise due to slip between the pulleys during running of the belt.

[Brief description of drawings]

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

FIG. 2 is a vertical sectional view of a V-cut edge type V-belt according to the present invention.

[Explanation of symbols]

1 V ribbed belt 2 cores 3 Adhesive rubber layer 4 Compressed rubber layer 5 Rubber canvas 6 rib part 21 V belt

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) F16G 1/08 F16G 1/08 A F term (reference) 4J002 AE053 BB271 CF002 CH023 CL002 CL062 EH038 EH098 EH138 EU056 EU186 EU196 FA032 FA037 FD023 FD028 FD146

Claims (7)

[Claims] 1. A transmission belt comprising an adhesive rubber layer having a core wire embedded along the longitudinal direction of the belt, and an elastic layer containing a compression rubber layer, wherein at least the compression rubber layer has 100 parts by mass of alkylated chlorosulfonated polyethylene. On the other hand, 1.0 to 5.0 parts by mass of a maleimide co-crosslinking agent, 10 to 20 parts by mass of short fibers, and 10 to 20 parts by mass of a plasticizer are blended. 2. The power transmission belt according to claim 1, wherein a sebacate plasticizer is used as the plasticizer. 3. The power transmission belt according to claim 1, wherein 25% or more of all the short fibers are para-aramid short fibers. 4. The V-ribbed belt, wherein the transmission belt is a V-ribbed belt including an adhesive rubber having a core wire embedded along the longitudinal direction of the belt and a compression rubber layer having a plurality of ribs extending in the circumferential direction of the belt. Power transmission belt. 5. A rubber composition for a power transmission belt, comprising an adhesive rubber layer having a core wire embedded along the longitudinal direction of the belt and an elastic layer containing a compressed rubber layer, wherein at least the compressed rubber layer is alkylated chlorosulfone. 1.0 to 5.0 parts by mass of maleimide-based co-crosslinking agent, 10 to 20 parts by mass of short fibers, and 10 to 20 parts of plasticizer per 100 parts by mass of polyethylene.
A rubber composition for a power transmission belt, which is blended in parts by mass. 6. The rubber composition for a power transmission belt according to claim 1, wherein a sebacate-based plasticizer is used as the plasticizer. 7. The rubber composition for a power transmission belt according to claim 1, wherein 25% or more of all the short fibers are para-aramid short fibers.