JPH11148535A - Transmission belt - Google Patents

Abstract

(57) [Problem] To provide a power transmission belt which does not cause environmental pollution even when incinerated and has excellent heat resistance, oil resistance, abrasion resistance and bending resistance. A power transmission belt having a rubber layer in which a core wire is bonded and embedded, wherein the rubber layer comprises ethylene, (meth)
Acrylic ester, and a crosslinked polymer comprising a crosslinked component as a component, wherein the core wire is a polyester fiber surface-treated with a mixture of resorcinol, formalin, and a latex having a carboxyl group. A transmission belt consisting of:

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 which does not generate harmful substances and is excellent in functionality.

[0002]

2. Description of the Related Art Power transmission belts are widely used in automobiles and general industries as friction transmission belts such as V belts such as wrapped belts and low edge belts and V rib belts.

Usually, a V-belt is shown in FIG. 1 and a V-ribbed belt is shown in FIG. 2, an adhesive rubber layer 12 having a core 11 bonded and embedded, and a compressed rubber layer 13 laminated on the adhesive rubber layer 12. The upper canvas 14 and the lower canvas 15 are adhered to this as necessary.

[0004] Devices for improving the life and reliability of the power transmission belt have been used for a long time. For example, a fiber made of polyester or the like is used as the core wire, and in order to improve the adhesion between the core wire and the adhesive rubber layer, sulfur is compounded in the rubber constituting the adhesive rubber layer, or thiuram vulcanization is performed. A device such as blending of an accelerator has been devised.

As the rubber used for the adhesive rubber layer and the compression rubber layer of such a power transmission belt, chloroprene rubber has been widely used. Chloroprene rubber is excellent in heat deterioration resistance, and has sufficient adhesiveness to the core wire.
Since the adhesiveness to the canvas can be improved, it was suitable as a rubber for a power transmission belt.

In recent years, harmful substances such as dioxins generated when incinerating chlorine-containing compounds have been attracting attention from the viewpoint of environmental protection. In view of the above, there has been devised to avoid chlorine-containing compounds in compounds constituting industrial products, and the use of chloroprene rubber containing chlorine as an essential element is being avoided.

For example, NBR and hydrogenated NBR have been put into practical use as a rubber for a power transmission belt in place of chloroprene rubber. However, under severe use conditions, these rubbers are inferior in heat resistance, oil resistance, etc., in fields where high mechanical properties are required, in fields where abrasion resistance is required, and high flex resistance is required. In the field and the like, the use has been limited.

[0008]

SUMMARY OF THE INVENTION In view of the above, the present invention provides a power transmission belt which does not cause environmental pollution even when incinerated and has excellent heat resistance, oil resistance, abrasion resistance and bending resistance. It is intended to do so.

[0009]

SUMMARY OF THE INVENTION The present invention is a power transmission belt having a rubber layer having a core wire bonded and embedded therein, wherein the rubber layer comprises ethylene, (meth) acrylate, and
It is composed of a cross-linked polymer having a cross-linking component as a component, and the core wire is resorcinol, formalin, and
This is a power transmission belt made of polyester fibers that have been surface-treated with a mixture of latex having a carboxyl group. Hereinafter, the present invention will be described in detail.

The power transmission belt of the present invention is composed of a cord, a rubber layer, and, if necessary, a canvas. In the power transmission belt of the present invention, the rubber layer is made of a crosslinked polymer having ethylene, a (meth) acrylic acid ester, and a crosslinking component as constituents, and the core wire is formed of a resorcinol, formalin, and a carboxyl group. It is characterized by the fact that it is made of polyester fibers that have been surface-treated with a mixture of latexes.

As the polymer crosslinked product having ethylene, (meth) acrylate and a crosslinking component as constituents, ethylene, (meth) acrylate and a third monomer as a crosslinking component can be used. A terpolymer may be used.

The above (meth) acrylate means acrylate and / or methacrylate. As the (meth) acrylic acid ester, an ester of an alcohol having 1 to 8 carbon atoms and (meth) acrylic acid is preferable. For example, methyl (meth) acrylate,
Examples include ethyl (meth) acrylate, n-butyl (meth) acrylate, and ethylhexyl (meth) acrylate. These can be used alone or in combination of two or more.

Examples of the third monomer include acrylic acid, methacrylic acid, acrylonitrile, vinyl acetate and the like; glycidyl acrylate, glycidyl methacrylate and allyl glycidyl ether containing an epoxy group.

The molar ratio of each component in the terpolymer is such that the molar ratio of ethylene to (meth) acrylate is 50:50 to 85:15, and ethylene and (meth)
The molar ratio of the third monomer to the total amount of the acrylate is preferably from 1:99 to 90:10. If the amount of ethylene is too large, the crystallinity of the copolymer becomes high and sufficient elasticity cannot be obtained.If the amount of ethylene is too small, the embrittlement point of the copolymer becomes high, which makes it difficult to use at low temperatures. is there. On the other hand, if the molar ratio of the third monomer is too small, the deteriorated form does not become hardened and deteriorated and cannot function as a compressed rubber, while if too large, the required rubber elasticity is lost.

In preparing the crosslinked polymer, a crosslinking agent is added. The crosslinking agent is not particularly limited, and examples thereof include urea derivatives, monoamines, and diamines that perform crosslinking based on a condensation reaction; diisocyanates and bisethyleneimine compounds that perform crosslinking based on an addition reaction.

The crosslinked polymer forms the rubber layer of the power transmission belt of the present invention. The polymer cross-linked product includes 1 to
It is preferred to include a vulcanizing agent in an amount of 2 phr. When the amount of the vulcanizing agent is less than 1 phr, the crosslink density of the polymer crosslinked product is reduced and the physical properties of the rubber are deteriorated. When the amount exceeds 2 phr, a mixture of resorcinol, formalin and a carboxyl group-containing latex described in detail below is used. Even with surface treatment, amine decomposed products caused by the vulcanizing agent,
It becomes difficult to prevent the core wire from deteriorating.

[0017] In the present specification, "phr" is
The ratio (parts by weight) with respect to 100 parts by weight of the rubber layer of the power transmission belt of the present invention means 1-2 phr, and
The amount is 1 to 2 parts by weight based on 00 parts by weight. The vulcanizing agent is not particularly limited, and various conventionally known vulcanizing agents can be used. Among them, hexamethylene diamine carbamate is preferable.

The core used in the power transmission belt of the present invention is made of polyester fiber. Examples of the polyester fiber include polyethylene terephthalate and the like. The polyester fiber is preferably subjected to immersion treatment with polyisocyanate in order to make the surface treatment described later more efficient.

The polyester fibers are resorcinol,
The surface is treated with a mixture of formalin and a latex having a carboxyl group (hereinafter referred to as “RFL mixture”). Conventionally, surface treatment with a mixture of resorcinol, formalin and latex has been conventionally performed in order to improve the adhesiveness between fiber and rubber.In the present invention, a carboxyl group is used as the latex used in this surface treatment. Using latex.

The core wire made of polyester fibers is deteriorated with time due to amine decomposition products generated during the polymerization of the polymer crosslinked product. In the present invention, since the core wire made of the polyester-based fiber is subjected to a surface treatment with the RFL mixture containing the latex having the carboxyl group, the amine-based decomposition product generated at the time of polymerization of the polymer crosslinked product is captured by the carboxyl group. The effect of the amine decomposition product on the core wire is prevented.

The surface treatment with the RFL mixture preferably has a basis weight of 0.04 or more. The basis weight is
If it is less than 0.04, it becomes difficult to prevent the amine decomposition product from affecting the core wire, and it is not possible to prevent core wire deterioration.

The Tg of the latex having a carboxyl group constituting the FRL mixture is from -15 to 150 ° C.
Is preferred. If the temperature is lower than -15 ° C, the cohesive force of the polymer becomes insufficient, so that the adhesive force is reduced. If the temperature exceeds 150 ° C, the flexibility of the power transmission belt is lowered. More preferably,
-15 to 90 ° C.

The above-mentioned latex having a carboxyl group may be obtained by subjecting a polymer of at least one acrylic ester or a copolymer of at least one acrylic ester and acrylonitrile to a carboxylation modification treatment. preferable. Examples of the above-mentioned at least one type of acrylic ester polymer that has been subjected to carboxylation modification include, for example, those obtained by subjecting an ethyl acrylate polymer to carboxylation modification. Examples of the carboxylation-modified copolymer of at least one acrylic ester and acrylonitrile include carboxylation-modified ethyl acrylate / butyl acrylate / acrylonitrile copolymer. .

The rubber layer of the power transmission belt of the present invention may be composed of two layers, an adhesive rubber layer in which the core wire is bonded and buried, and a compressed rubber layer which is a main part of the rubber layer. Good. In this case, both the adhesive layer and the compressed rubber layer can be made of the above-mentioned ethylene, (meth) acrylic acid ester, and a crosslinked polymer having a crosslinking component as a constituent.

The transmission belt of the present invention is further provided with an upper canvas and a lower canvas as required. Examples of the canvas include cotton, a blend of cotton and polyester, and a blend of cotton and polyamide.

[0026]

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.

Example 1 An ethylene-acrylate polymer blend shown in Table 1 was used as a compressed rubber layer, and RF was shown in Formulation 1 in Table 2.
The V-belt shown in FIG. 1 was produced using a polyethylene terephthalate cord (9A-0668, manufactured by Toray Industries, Inc.) treated with the L mixture as a core wire. The polyethylene terephthalate cord used had been immersed in polyisocyanate before being treated with the RFL mixture. The belt vulcanization conditions were 170 ° C., 30 minutes, and steam vulcanization.

The obtained V-belt is wrapped around a driving pulley of φ70 and a driven pulley, and 784 N is applied to the driven pulley.
(80Kgf) load, room temperature, rotation speed 4900r
Acceleration evaluation was performed under pm conditions. V after running for 200 hours
The condition of the belt was checked. As a result, no major defects that adversely affected the running of the belt were found. Also, no deterioration of the core wire in the belt or deterioration of the bonding state was observed.

Further, using an ethylene-acrylate polymer blend shown in Table 1 and a polyethylene terephthalate cord treated with the RFL mixture shown in Formulation Example 1 in Table 2, a three-peel test was carried out (180). ° peeling)
Was done. The test piece was prepared at 170 ° C. for 30 minutes.
The test was performed under the conditions of press vulcanization. As a result, it was in the form of rubber cohesion failure with rubber attached to the core wire, and the adhesive force was 12.3.
kgf / 3.

Example 2 A V-belt was produced in the same manner as in Example 1, except that a polyethylene terephthalate cord treated with the RFL mixture shown in Formulation Example 2 in Table 2 was used as a core wire. The obtained V-belt was evaluated for acceleration in the same manner as in Example 1. The state of the V-belt after traveling for 200 hours was examined. As a result, no major defects that adversely affected the running of the belt were found. Also, no deterioration of the core wire in the belt and no deterioration of the bonding state were observed.

Further, a strip test of three cords was performed in the same manner as in Example 1 with these configurations. As a result, it is in the form of rubber cohesion failure with rubber attached to the core wire, and the adhesive force is 1
It was 1.0 kgf / 3.

Comparative Example 1 A V-belt was produced in the same manner as in Example 1 except that a polyethylene terephthalate cord treated with the RFL mixture shown in Formulation Example 3 in Table 2 was used as a core wire. The obtained V-belt was evaluated for acceleration in the same manner as in Example 1. As a result, the core wire was deteriorated, and the cord jumped out after 42 hours of running of the belt.

Further, a strip test of three cords was performed in the same manner as in Example 1 with these configurations. As a result, it was a form of interface destruction between the core wire and the rubber surface, and there was no rubber adhesion on the surface of the core wire, and the adhesive strength was 2.3 kgf / 3.

[0034]

[Table 1]

The following compounds were used as the compounds shown in Table 1. Further, 10 parts by weight of water was further added to the composition for the three-peel peel test to reproduce steam vulcanization. E-EH: Ethylene-acrylic acid ester-acrylic acid copolymer (VAMAC HG (Moony viscosity; 27 ± 3 ML (1 + 4) 100 ° C., manufactured by DuPont)) Carbon black: FEF carbon Plasticizer: polyether-based Process oil (Adekasizer RS-735) Vulcanizing agent: hexamethylenediamine carbamate Vulcanization accelerator: di-o-tolylguanidine

[0036]

[Table 2]

The following compounds were used as the compounds shown in Table 2. Latex 1: Carboxylated modified type of ethyl acrylate polymer (solid content ratio 45%, Tg = -6 ° C.) Latex 2: Ethyl acrylate / butyl acrylate / carboxylated modified type of acrylonitrile copolymer (solid content ratio 45%, Tg = −10 ° C.) Latex 3: Styrene / butadiene / vinylpyridine (solid content ratio 45%, Tg = −53 ° C.)

The evaluation results of Example 1, Example 2, and Comparative Example 1 are summarized in Table 3.

[0039]

[Table 3]

EXAMPLE 3 A polyethylene terephthalate cord (9A-0668) treated with an ethylene-acrylate polymer blend shown in Table 4 as a compressed rubber layer and treated with an RFL mixture shown in Table 4 in Example 4 was used. , Manufactured by Toray Industries, Inc.), and a V-belt was produced. The polyethylene terephthalate cord used had been immersed in polyisocyanate before being treated with the RFL mixture. The belt vulcanization conditions were 170 ° C., 30 minutes, and steam vulcanization.

The obtained V belt is hung on a driving pulley of φ70 and a driven pulley, and 784 N is applied to the driven pulley.
(80Kgf) load, room temperature, rotation speed 4900r
Acceleration evaluation was performed under pm conditions. V after running for 200 hours
The condition of the belt was checked. As a result, no major defects that adversely affected the running of the belt were found. Also, no deterioration of the core wire in the belt or deterioration of the bonding state was observed.

Further, the ethylene-
Using a acrylate polymer blend and a polyethylene terephthalate cord treated with the RFL mixture shown in Formulation Example 4 in Table 5, three cord peeling tests (18
0 ° peeling). The preparation of the test piece was 170
C., 30 minutes under press vulcanization conditions. As a result, it was in the form of rubber cohesion failure with rubber adhered to the core wire, and the adhesive strength was 19.3 kgf / 3.

COMPARATIVE EXAMPLE 2 The ethylene-acrylic acid ester polymer compound shown in the compounding example in Table 4 was used as a compressed rubber layer, and the polyethylene terephthalate cord treated with the RFL mixture shown in compounding example 5 in Table 5 was used as a core wire. A V-belt was produced in the same manner as in Example 3, except that the V-belt was used. The obtained V-belt was evaluated for acceleration in the same manner as in Example 3. As a result, the core wire was deteriorated, and a cord jumped out after 72 hours of running of the belt.

Further, a strip test of three cords was performed in the same manner as in Example 3 with these structures. As a result, it was a form of interface destruction between the core wire and the rubber surface, and no rubber adhered to the surface of the core wire, and the adhesive strength was 4.2 kgf / 3.

COMPARATIVE EXAMPLE 3 The ethylene-acrylic acid ester polymer compound shown in the compounding example in Table 4 was used as a compressed rubber layer, and the polyethylene terephthalate cord treated with the RFL mixture shown in compounding example 4 in Table 5 was used as a core wire. A V-belt was produced in the same manner as in Example 3, except that the V-belt was used. The obtained V-belt was evaluated for acceleration in the same manner as in Example 3. As a result, the core wire was deteriorated, and the cord jumped out after 28 hours of running of the belt.

Further, a strip test of three cords was carried out in the same manner as in Example 3 with these structures. As a result, it was a form of interface destruction between the core wire and the rubber surface, there was no rubber adhesion on the surface of the core wire, and the adhesive strength was 2.7 kgf / 3.

[0047]

[Table 4]

[0048]

[Table 5]

[0049]

[Table 6]

[0050]

Since the power transmission belt of the present invention has the above-described structure, it does not cause environmental pollution even when incinerated, and has excellent heat resistance, oil resistance, wear resistance, and bending resistance. is there.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a V-belt which is an embodiment of a power transmission belt of the present invention.

FIG. 2 is a schematic cross-sectional view of a V-rib belt as one embodiment of the power transmission belt of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Core wire 12 Adhesive rubber layer 13 Compression rubber layer 14, 15 Canvas

Claims (5)

[Claims] 1. A power transmission belt having a rubber layer in which a core wire is bonded and embedded, wherein the rubber layer is formed of ethylene, (meth)
An acrylic acid ester, and a crosslinked polymer comprising a crosslinked component as a constituent, wherein the core wire is a polyester fiber surface-treated with a mixture of resorcinol, formalin, and a latex having a carboxyl group. A power transmission belt, comprising: 2. The power transmission belt according to claim 1, wherein the crosslinked polymer constituting the rubber layer contains 1 to 2 phr of a vulcanizing agent. 3. The power transmission belt according to claim 2, wherein the vulcanizing agent is hexamethylene diamine carbamate. 4. T of a latex having a carboxyl group
The power transmission belt according to claim 1, 2 or 3, wherein g is -15 to 150C. 5. A latex having a carboxyl group,
A polymer of at least one acrylic ester, or
The power transmission belt according to claim 1, wherein a copolymer of at least one type of acrylic ester and acrylonitrile is subjected to a carboxylation modification treatment.