JPH09290486A - V-belt for transmitting power - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide excellent flexing properties, wear resistance and side pressure rigidity by preventing the pop-out of a core wire. SOLUTION: The V-belt 1 for transmitting power comprises a high tensile material layer 4 for embedding core wires 3 in adhesive rubber 2, an elongated rubber layer 5 of the upper surface of the layer 4, and a compressed rubber layer 6 of the lower surface of the layer 4. In this case, the layer 6 uses the rubber obtained by mixing an unsaturated metal carboxylate salt and an organic peroxide with a hydrogenated nitrile rubber and crosslinking it, and the layer 2 uses the rubber obtained by mixing the unsaturated metal carboxylate salt, silica and the organic peroxide with the hydrogenated nitrile rubber and crosslinking it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-belt for power transmission which is used by being hung on a V-pulley, and has particularly excellent flexibility and heat transmission, abrasion resistance and lateral pressure rigidity. V-belt for use.

[0002]

2. Description of the Related Art In recent years, with the increase in engine output and rotation speed, the operating environment temperature of the power transmission V-belt has risen and the lateral pressure received from the V-pulley on the power transmission belt has also risen. The quality required for such a belt is that the lateral pressure rigidity when driving the belt is large, the abrasion resistance is good, and the flexibility in the belt longitudinal direction is excellent.

Conventional V-belts for power transmission are mainly made of chloroprene rubber. However, this material is liable to be hardened in a high temperature atmosphere, and cracks due to hardening occur early, and lateral pressure rigidity is high in a high temperature atmosphere. If the belt is insufficient, it deforms so as to fall into the pulley, causing buckling deformation called dishing, which makes it impossible to transmit power, or peeling between the core wire and the adhesive rubber causes failures such as pop-out. There was a problem of reaching the belt life. Therefore, JP-A-5-271
As disclosed in Japanese Patent No. 472, a rubber composition using a rubber composition in which an unsaturated carboxylic acid metal salt such as zinc methacrylate is dispersed in hydrogenated nitrile rubber as a belt having excellent wear resistance and heat resistance. An object and a transmission belt using the same have been proposed.

[0004]

However, in the case of a V-belt for which a high load transmission is particularly required, Japanese Patent Application Laid-Open No. 5-2 / 1992 has been proposed.
Although the heat resistance and abrasion resistance are improved by using the rubber composition disclosed in Japanese Patent No. 71472, the problem of pop-out of the core wire due to the separation of the core wire and the adhesive rubber due to the high hardness of the rubber is solved. It has not been. Further, it is insufficient in terms of lateral pressure rigidity to be used as a compression rubber layer of a V belt for high load transmission, and further improvement has been required. Therefore, an object of the present invention is to provide a power transmission V-belt that prevents the core from popping out and is excellent in flexibility, heat resistance, wear resistance, and lateral pressure rigidity.

[0005]

In order to achieve such an object, the present invention provides a tensile member layer in which a core wire is embedded spirally in the adhesive rubber along the longitudinal direction of the belt, and the tensile member. In a power transmission V-belt composed of an extension rubber layer laminated on the upper surface of the layer and a compression rubber layer laminated on the lower surface of the tensile body layer, the compression rubber layer is a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt and an organic peroxide. A rubber obtained by mixing an oxide and crosslinking is used, and the adhesive rubber is a rubber obtained by mixing a hydrogenated nitrile rubber with an unsaturated carboxylic acid metal salt, silica and an organic peroxide and crosslinking the rubber.

Further, as a specific compounding amount of the compressed rubber layer, a polymer composition 1 in which hydrogenated nitrile rubber and unsaturated carboxylic acid metal salt are compounded at 98: 2 to 55:45 is used.
0.2 to 10 parts by weight of organic peroxide based on 00 parts by weight,
A compounded and crosslinked rubber is used, and an unsaturated carboxylic acid metal salt is added to hydrogenated nitrile rubber as an adhesive rubber at 98:
2 to 55:45 with respect to 100 parts by weight of the polymer composition, silica 5 to 50 parts by weight, organic peroxide 0.2 to
It is preferable to use a rubber obtained by mixing 10 parts by weight and crosslinking.

Further, a low-edge cog belt having a cog portion at a predetermined pitch on the upper and lower surfaces of the belt over the entire circumference in the longitudinal direction of the belt, a cog position substantially above and below the belt, and a compressed rubber layer In which 5 to 40 parts by weight of short fibers are dispersed in 100 parts by weight of the rubber composition, and the short fibers are oriented in the belt width direction, and more preferably 100 parts by weight of the rubber composition in the compressed rubber layer. In the present invention, short fibers in a proportion of 15 to 30 parts by weight are dispersed and the short fibers are oriented in the belt width direction. As the short fibers, it is advantageous to use short fibers adhered with an epoxy resin-based treatment liquid and a mixed liquid of resorcin, formalin and rubber latex.

[0008]

In the present invention, the use of hydrogenated nitrile rubber containing an unsaturated carboxylic acid metal salt on the lower surface of the belt allows the belt to have excellent heat resistance, abrasion resistance and lateral pressure rigidity. Even when used in an atmosphere, it is possible to prevent cracks from being generated early, do not dish on the lateral pressure from the V pulley, and wear of the belt side surface is small. Further, by blending silica in addition to unsaturated carboxylic acid in the adhesive rubber, the adhesiveness of the adhesive rubber is increased and the pop-out of the core wire can be prevented, so that a belt having a long life can be obtained.

[0009]

1 is a cross-sectional perspective view of a main portion of a low edge cog belt which is an example of a V belt for power transmission according to the present invention. The power transmission V-belt 1 of the present invention includes an adhesive rubber 2
The tensile body layer 4 in which the core wire 3 is embedded in a spiral shape along the longitudinal direction of the belt, the stretched rubber layer 5 laminated on the upper surface of the tensile body layer 4, and the lower surface of the tensile body layer 4. It is composed of a laminated compressed rubber layer 6.

As the core wire 3, a rope having a low elongation and a high strength is used, and an organic fiber such as aramid fiber, polyamide fiber or polyester fiber, or a twisted rope made of inorganic fiber such as glass fiber or metal fiber is mentioned. To be This core line 3
Is generally bonded to the adhesive rubber 2 by a resorcin-formalin-latex treatment. Further, a surface treated with resorcin-formalin-latex and further coated with rubber paste may also be used.

Next, the rubber forming the compressed rubber layer 6 is obtained by blending a hydrogenated nitrile rubber with an unsaturated carboxylic acid metal salt and an organic peroxide and crosslinking the mixture. By blending an unsaturated carboxylic acid metal salt with hydrogenated nitrile rubber having good heat resistance, a rubber having excellent heat resistance, high strength and abrasion resistance can be obtained.

The hydrogenated nitrile rubber used in the present invention is not particularly limited, but the Mooney viscosity (M
It is preferable that L1 + 4 (100 ° C.)) is 70 to 85 in order to improve mechanical strength and lateral pressure rigidity, and also to improve flexibility and workability.

The unsaturated carboxylic acid metal salt is an ionic bond between an unsaturated carboxylic acid having a carboxyl group and a metal, and examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid and other monocarboxylic acids, maleic acid and fumaric acid. acid,
Dicarboxylic acids such as itaconic acid are preferable, and the metal includes beryllium, magnesium, calcium, strontium, barium, titanium, chromium, molybdenum, manganese, iron, cobalt, nickel, copper, silver, zinc, cadmium, aluminum, tin, lead. , Antimony, etc. can be used.

The composition ratio of the hydrogenated nitrile rubber and the rubber composed of the unsaturated carboxylic acid metal salt is 98: 2-5.
It is set to 5:45. If the ratio of the hydrogenated nitrile rubber is more than 98, the abrasion resistance will be insufficient, and if it is less than 55, the abrasion resistance will be good, but the flexibility of the belt will be poor, which is not preferable.

The organic peroxide is used as a crosslinking agent and includes di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide,
1.1-t-butylperoxy-3.3.5 trimethylcyclohexane, 2.5-di-methyl-2.5-di (t-
Butyl peroxy) 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 and the like are used. And as the compounding amount thereof, the rubber composition 10
0.2 to 10 parts by weight with respect to 0 parts by weight. This is because if it is less than 0.2 parts by weight, sufficient crosslinking cannot be carried out, and if it exceeds 10 parts by weight, sufficient elasticity cannot be obtained.

In the present invention, it is also possible to use a product obtained by finely dispersing a metal salt of unsaturated carboxylic acid in a hydrogenated nitrile rubber, blending the hydrogenated nitrile rubber alone, and crosslinking it with an organic peroxide. In that case, the ratio of the unsaturated carboxylic acid metal salt finely dispersed in the range of 10 to 100 parts by weight with respect to 100 parts by weight of the hydrogenated nitrile rubber and the simple addition of the hydrogenated nitrile rubber are 20:80 to 90:10. Use the one blended in.

If the amount of the unsaturated carboxylic acid metal salt is less than 10 parts by weight, the abrasion resistance is insufficient, and if it is more than 100 parts by weight, the abrasion resistance is good but the bending fatigue is deteriorated, which is not preferable. Further, hydrogenated nitrile rubber in which an unsaturated carboxylic acid metal salt is finely dispersed and hydrogenated nitrile rubber alone are blended at a ratio of 20:80 to 90:10. If the amount of the hydrogenated nitrile rubber in which the unsaturated carboxylic acid metal salt is finely dispersed is less than 20 parts by weight, the expected abrasion resistance and lateral pressure rigidity cannot be obtained. Further, if it exceeds 90 parts by weight, the flexibility is deteriorated.

Further, by mixing and dispersing short fibers 7 in the compressed rubber layer 6 and orienting them in the width direction of the belt, lateral pressure rigidity can be reinforced and the friction coefficient can be reduced, but short polyester fibers are used as short fibers. Fibers, polyamide short fibers, aramid short fibers, etc. are mixed in an amount of 5 to 40 parts by weight, more preferably 15 to 30 parts by weight, based on 100 parts by weight of the rubber composition. If it is less than 5 parts by weight, the effects of reinforcing lateral pressure rigidity and reducing the friction coefficient are insufficient, and if it exceeds 40 parts by weight, it becomes difficult to knead the rubber, and the bending fatigue resistance and heat resistant running life of the belt are increased. Is not preferable because the problem of decrease in the value becomes remarkable. A more preferable range of 15 to 30 parts by weight is a range in which the same problem can be solved at a higher level.

Further, the short fibers can be firmly adhered to the rubber by subjecting them to an adhesive treatment in advance, so that a belt having a longer life can be obtained. In order to bond the hydrogenated nitrile rubber containing the unsaturated carboxylic acid metal salt used in the compressed rubber layer 6 of the belt in the present invention, the following adhesion treatment is preferably performed.

The short fibers are first dipped in an epoxy type treatment solution and heated and dried, and then dipped in a mixed solution (RFL treatment solution) of resorcin, formalin and rubber latex and heat treated. The epoxy resin-based treatment liquid is a treatment liquid whose main component is an epoxy compound having two or more epoxy groups in the molecule, and specific preferred examples of the epoxy compound include diglycerol, triglyceryl tetraglycidyl ether, or , Tetraglycerol pentaglycidyl ether and the like.

The RFL treatment liquid used has a molar ratio of resorcin and formalin in the range of 1: 2 to 2: 1, and the ratio of the solid content of rubber latex and the solid content of resorcin and formalin is 1: 1 to 1: 1. Those in the range of 10 are usually used. As the rubber latex, acrylonitrile-butadiene copolymer rubber latex, carboxylated acrylonitrile-butadiene copolymer rubber latex, styrene-butadiene copolymer rubber latex, vinyl pyridine rubber latex, chlorosulfonated polyethylene rubber latex, hydrogenated Acrylonitrile-butadiene copolymer rubber latex and the like are used, but use of acrylonitrile-butadiene copolymer rubber latex is particularly preferable.

The rubber of the compressed rubber layer 6 may include a reinforcing agent such as carbon black and silica, calcium carbonate,
Filler, cross-linking aid to improve wear resistance of talc, etc.
Various commonly used additives such as vulcanization accelerators, plasticizers, stabilizers, processing aids, antioxidants, and colorants may be blended according to the intended purpose. Further, a method of mixing rubber and various additives is usually used, and for example, a method of kneading using a Banbury mixer or a kneader can be mentioned.

As the adhesive rubber 2, hydrogenated nitrile rubber having unsaturated carboxylic acid metal salt dispersed therein, hydrogenated nitrile rubber, chlorosulfonated polyethylene, natural rubber, chloroprene rubber, styrene-butadiene rubber, butadiene rubber are used. And the like, or a single material thereof or a blend thereof. Further, as an example of the rubber used for the stretched rubber layer 5 laminated and adhered to the upper surface of the tensile body layer 4, the same kind of rubber as the adhesive rubber 2 can be cited.

Although only examples of the rubber used for the adhesive rubber 2 and the stretched rubber layer 5 are given, it goes without saying that the vulcanized or crosslinked rubber constitutes the finished product of the belt, such as carbon black and silica which are usually used. Reinforcements and calcium carbonate,
Fillers such as talc, crosslinking aids, vulcanization accelerators, plasticizers,
It contains various additives such as stabilizers, processing aids, anti-aging agents and colorants.

In the present application, a belt having a high strength and a long life is obtained by using, in the compression rubber layer 6, hydrogenated nitrile rubber in which an unsaturated carboxylic acid metal salt is mixed and crosslinked with an organic peroxide. The strength of the entire belt can be improved by using the hydrogenated nitrile rubber containing the same unsaturated carboxylic acid metal salt not only in the compressed rubber layer 6 but also in the adhesive rubber 2. However, in the case of the adhesive rubber 2, if the adhesive force with the core wire 3 is not sufficient, the rubber and the core wire are easily peeled off, and a problem such as pop-out occurs. The rubber in which the unsaturated carboxylic acid metal salt is finely dispersed in the hydrogenated nitrile rubber has a poor adhesion to the core wire, so that the pop-out phenomenon easily occurs as it is.

Therefore, by adding silica, it is possible to obtain a belt having a sufficient adhesive force between the rubber and the core wire.
In order to impart appropriate adhesive strength, a rubber composition 100 comprising hydrogenated nitrile rubber and unsaturated carboxylic acid metal salt
Silica is blended in the range of 5 to 50 parts by weight with respect to parts by weight. If the amount is less than 5 parts by weight, sufficient adhesive force cannot be obtained,
If it exceeds 50 parts by weight, the viscosity in the uncrosslinked state is high and the processability is deteriorated, and the hardness after crosslinking is unnecessarily increased, which is apt to cause cracks, which is not preferable.

The organic peroxide used for rubber cross-linking is easily affected by pH and easily causes ionic decomposition in an acidic atmosphere. Therefore, magnesium oxide, triethanolamine, diphenylguanidine and hexamethylene are used for pH adjustment. A basic substance such as tetramine may be added. The amount of addition varies depending on the type, but a rubber composition comprising hydrogenated nitrile rubber and unsaturated carboxylic acid metal salt 10
It is about 0.5 to 10 parts by weight with respect to 0 parts by weight. 0.
If it is less than 5 parts by weight, the effect of adjusting the pH is thin, and if it exceeds 10 parts by weight, the viscosity is high in the uncrosslinked state and the processability is deteriorated as in the case of silica, and the hardness after crosslinking becomes unnecessarily high. It is not preferable because cracks easily occur. The above metal oxides such as magnesium oxide and zinc oxide can be blended for the purpose of increasing the hardness of the rubber, and are added in the range of 0.5 to 10 parts by weight with respect to 100 parts by weight of the rubber composition.

Further, the rubber in which the unsaturated carboxylic acid metal salt is dispersed, which is used for the compressed rubber layer 6 in the above description, can be used for the stretched rubber layer 5 of the belt, if necessary, so that it is more abrasion resistant. It is possible to obtain a belt having excellent properties and lateral pressure rigidity. Suitable applications for using the belt as described above include a low edge cog belt used as a drive transmission belt in a high temperature atmosphere such as a snowmobile or a scooter. As a type of this low-edge cog belt, one having a cog only on the compression rubber layer on the lower surface of the belt as shown in FIG. 1 and one having a cog on the extension rubber layer on the upper surface of the belt to further improve the flexibility of the belt are shown in FIG. There is something like the one shown.

The speed change belt is a belt which is required to have lateral pressure rigidity and flexibility which are particularly excellent in use. When a hydrogenated nitrile rubber in which an unsaturated carboxylic acid metal salt is dispersed is used in the compression rubber layer of this belt, It is possible to obtain a belt having improved belt strength, lateral pressure rigidity, wear resistance, and heat resistance. However, in order to improve the flexibility in the longitudinal direction of the belt, the shape of the belt should be a belt having cogs on both the upper surface and the lower surface of the belt, and the positions of the upper surface and the lower surface should be the same. It is preferable to arrange them in It can be said that it is most preferable to match the positions of the upper surface cog and the lower surface cog in the strict sense, but if the positions are substantially in the same range, the present invention can be used. It is appropriate to be included in the range.

[0030]

EXAMPLES Examples 1 to 3 and Comparative Examples 1 to 6 shown in Table 1 below.
The kneaded mixture was used to prepare vulcanized rubber physical properties of each rubber and a low edge cog belt, and a running test was conducted.

[0031]

[Table 1]

[0032]

[Table 2]

As is clear from Table 2, the V belt for power transmission of the present invention has heat resistance and abrasion resistance superior to those of the conventional belt made of chloroprene or hydrogenated nitrile rubber, and also the belt. The life of the belt can be improved by making the shape of (1) to have upper and lower cogs and matching the positions of the upper and lower cogs. Next, tests were conducted on belts with different blending amounts of hydrogenated nitrile rubber and unsaturated carboxylic acid metal salt.

[0034]

According to the present invention, the hydrogenated nitrile rubber cross-linked with the organic peroxide having the unsaturated carboxylic acid metal salt dispersed therein is used as at least the compression rubber layer in the power transmission V-belt. Since it has excellent lateral pressure rigidity and wear resistance, cracks occur due to premature curing in high temperature atmosphere, and due to insufficient lateral pressure rigidity in high temperature atmosphere, the belt deforms to fall into the pulley and is called a dishing. It is possible to prevent failures such as pop-out due to the problem of deformation and peeling between the core wire and the adhesive rubber, and to have a very long life V for power transmission.
You can get a belt.

[Brief description of drawings]

FIG. 1 is a perspective sectional view of an essential part of a power transmission V-belt according to the present invention.

FIG. 2 is a perspective sectional view of an essential part of another embodiment of a power transmission V-belt according to the present invention.

[Explanation of symbols]

 1 V-belt for power transmission 2 Adhesive rubber 3 Core body 4 Tensile body layer 5 Extension rubber layer 6 Compression rubber layer 7 Cog 8 Cog

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area F16G 5/20 F16G 5/20 B

Claims (8)

[Claims] 1. A tensile body layer in which a core wire is embedded in a spiral shape in an adhesive rubber along a longitudinal direction of a belt, an expanded rubber layer laminated on an upper surface of the tensile body layer, and the tensile body layer. In a power transmission V-belt composed of a compressed rubber layer laminated on the lower surface,
The compression rubber layer uses a rubber obtained by mixing unsaturated carboxylic acid metal salt and organic peroxide in hydrogenated nitrile rubber and crosslinking the rubber,
The adhesive rubber is a V-belt for power transmission characterized by using a rubber obtained by blending hydrogenated nitrile rubber with unsaturated carboxylic acid metal salt, silica and organic peroxide to crosslink. 2. An organic peroxide of 0.2 to 10 is added to 100 parts by weight of a polymer composition in which a compression rubber layer contains hydrogenated nitrile rubber and unsaturated carboxylic acid metal salt in a ratio of 98: 2 to 55:45. The V-belt for power transmission according to claim 1, wherein parts by weight and rubber which is compounded and cross-linked are used. 3. 5 to 5 silica based on 100 parts by weight of a polymer composition prepared by blending hydrogenated nitrile rubber as an adhesive rubber with an unsaturated carboxylic acid metal salt at 98: 2 to 55:45.
A rubber obtained by mixing 0 parts by weight and 0.2 to 10 parts by weight of an organic peroxide and crosslinking the rubber is used.
V-belt for power transmission described in. 4. The V-belt for power transmission according to claim 1, wherein the V-belt is a low-edge cog belt having cog portions at predetermined pitches on both upper and lower surfaces of the belt over the entire circumference in the belt longitudinal direction. 5. The power transmission V-belt according to claim 4, wherein the cogs are substantially aligned above and below the belt. 6. The compressed rubber layer according to claim 1, wherein 5 to 40 parts by weight of short fibers are dispersed in 100% by weight of the rubber composition, and the short fibers are oriented in the belt width direction. V belt for power transmission. 7. The compressed rubber layer according to claim 1, wherein 15 to 30 parts by weight of short fibers are dispersed in 100 parts by weight of the rubber composition, and the short fibers are oriented in the belt width direction. V belt for power transmission 8. The power transmission V-belt according to claim 6, wherein the short fibers are made of short fibers adhered with an epoxy resin-based treatment liquid and a mixed liquid of resorcin, formalin and rubber latex.