JPH07138831A - Glass fiber cord for rubber reinforcement and power transmission belt using the same - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the breakage of glass fiber cord due to water resistance deterioration and greatly improve the belt life. [Structure] A glass fiber cord (belt tension member) 4 in which a resorcin-formalin-rubber latex dipping treatment is applied to a belt body 3 with respect to a strand made of a glass element wire that has been acid-treated before sizing agent treatment Buried.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass fiber cord for rubber reinforcement and an improvement of a transmission belt using the same, and more particularly to measures for improving water resistance.

[0002]

2. Description of the Related Art In recent years, demands for improving the life and reliability of power transmission belts are increasing. As such a transmission belt, a toothed belt is widely used in various fields. In particular, an OHC driving toothed belt used for an automobile engine is used under high load and multi-axis, and is also subjected to a high temperature condition of 100 to 140 ° C. due to the heat of the engine. In addition, rain may enter the engine room depending on the weather while driving, and high humidity conditions may occur due to the synergy with the heat of the engine. Due to such severe conditions, there is a problem that the service life of the toothed belt is shortened.

As one mode of shortening the service life of the toothed belt, when a glass fiber cord is used as a belt tension member, there is also a case where the glass fiber cord is broken due to water resistance deterioration to belt cutting. Therefore, in order to increase the service life of the toothed belt, it is necessary to improve the water resistance of the glass fiber cord.

Conventionally, as a means for improving the water resistance of the glass fiber cord, it has been generally adopted that a protective layer is provided on the surface of the cord or that the glass fiber cord itself has good water resistance. ing.

[0005]

However, in the former method described above, the protective layer is a water-based material because of the characteristics of glass, which is the material of the glass fiber cord, and no dramatic improvement in water resistance is observed. On the other hand, the latter method has a problem that the cost becomes high.

The present invention has been made in view of the above points, and an object of the present invention is to reduce the water absorption rate of the glass fiber cord itself by appropriately treating the glass element wire to reduce the water resistance thereof. When used as a tensile member of a transmission belt, the breakage due to water resistance deterioration of the glass fiber cord is prevented, and the belt life is greatly improved.

[0007]

In order to achieve the above object, the first means for solving the problems of the present invention is to use, as a glass fiber cord, a strand composed of a glass element wire that has been acid-treated before the sizing agent treatment. On the other hand, resorcin-formalin-
It is characterized in that it is obtained by dipping rubber latex.

A second solution means of the present invention is, in the first solution means, wherein hydrochloric acid is used as an acid used for the acid treatment,
It is characterized in that the concentration of the hydrochloric acid is 0.05 to 0.1N.

A third solution of the present invention is a glass fiber for rubber reinforcement, in which a resorcin-formalin-rubber latex is dipping-processed on a strand consisting of an acid-treated glass element wire before the sizing agent treatment. The feature is that the cord is embedded in the belt body.

According to a fourth solution of the present invention, in the third solution, hydrochloric acid is used as an acid used for the acid treatment,
It is characterized in that the concentration of the hydrochloric acid is 0.05 to 0.1N.

The glass strands constituting the strands of the glass fiber cord used in the present invention are typically E
Examples thereof include glass, K glass, U glass and S glass, but are not particularly limited thereto.

The sizing agent treatment referred to in the present invention is a treatment performed to increase the adhesive strength of the glass filaments so that they do not come apart from each other. Examples of the sizing agent include silanes such as aminosilane, vinylsilane and epoxysilane. Coupling agent, latex of natural rubber, synthetic rubber, etc. and vinyl, acrylic, usually emulsified,
A mixture of resins such as urethane-based, vinyl acetate-based, epoxy-based and modified products thereof is used.

The treating agent used in the acid treatment of the present invention is not particularly limited, but for example, hydrochloric acid, sulfuric acid, hydrofluoric acid or the like may be used, and the concentration is preferably 0.05 to.
It is 0.1 N hydrochloric acid. The concentration of hydrochloric acid was set in this way because when it exceeds 0.1 N, the strength of the glass strand decreases due to the acid treatment, while when it is less than 0.05 N, the expected effect of the acid treatment cannot be obtained. is there.

This acid treatment is carried out before the above sizing agent treatment. That is, the molten glass is pushed from a pot to form a glass element wire, and this glass element wire is washed with a treatment agent such as hydrochloric acid and acid-treated before being washed with water. This acid treatment elutes the hydrophilic component from the surface layer of the glass filament and causes hydrogen substitution of the alkali metal, forming a water resistant layer on the surface of the glass fiber cord made of this glass filament to absorb water. It is possible to suppress a decrease in the rate and prevent breakage due to water resistance deterioration of the glass fiber cord.

The acid treated glass filaments are washed with water, treated with a sizing agent, and then bundled into strands, and the resorcin-formalin-rubber latex (RF) is applied to the strands.
The glass fiber cord of the present invention is obtained by dipping L). This RFL treatment is called an adhesive treatment, and when the glass fiber cord is used as a tensile member (core wire) of a transmission belt such as a toothed belt, it is applied to improve the adhesiveness with the rubber forming the belt body. And is performed by a normal dipping method. Further, by performing this treatment before the final twisting of the glass fiber cord, more uniform impregnation and coating between the filaments are achieved.

The RFL is a mixed solution of a resorcin-formalin (RF) condensate and a rubber latex (L), and a polymerization ratio of resorcin-formalin in the resorcin-formalin (RF) condensate is 1: 0.5. ~
The ratio is 1: 3 mol, preferably 1: 1 to 1: 2 mol. The mixing ratio of the RF resin and the rubber latex is 1: 5 to 1:20 wt% in terms of solid content. Preferably, in the case of the present invention using a glass fiber cord as a tension member of the power transmission belt, the ratio is 1:10 to 1:20 wt.

The latex used here is, for example, hydrogenated nitrile rubber (H-NBR) latex, and this H-NBR latex has hydrogenated the conjugated diene unit portion of the unsaturated nitrile-conjugated diene copolymer rubber. Unsaturated nitrile-conjugated diene-ethylenically unsaturated monomer three-dimensional copolymer rubber and hydrogenated conjugated diene unit portion of this rubber; unsaturated nitrile-ethylenically unsaturated monomer copolymer rubber, and the like. In the unsaturated nitrile-ethylenically unsaturated monomer-based copolymer rubber, a part of the unsaturated monomer is replaced with a non-conjugated diene such as vinyl norbornene, dicyclopentadiene, and 1,4-hexadiene and copolymerized. It may be

The H-NBR is specifically a butadiene-acrylonitrile copolymer rubber, an isoprene-butadiene-acrylonitrile copolymer rubber, a hydrogenated isoprene-acrylonitrile conjugated diene or the like; butadiene-methyl acrylate-acrylonitrile copolymer rubber. ,
Butadiene-acrylic acid-acrylonitrile copolymer rubber or the like and hydrogenated products thereof; butadiene-ethylene-acrylonitrile copolymer rubber, butyl acrylate-ethoxyethyl acrylate-vinyl chloroacetate-acrylonitrile copolymer rubber, butyl acrylate-ethoxyethyl acrylate- Vinyl norbornene-
Examples thereof include acrylonitrile copolymer rubber, which can be obtained by using a usual polymerization method and a usual hydrogenation method.

As the latex, a latex in a polymerization completed state may be used, or a solid rubber dissolved in a solvent and dispersed in water (called post-emulsification) may be used.

When the glass fiber cord treated with acid as described above is used as a belt tension member,
This is embedded in the belt body to form a transmission belt. That is, by vulcanizing and adhering the glass fiber cord to the rubber layer as a belt tension member, as shown in FIG. 1, the back rubber layer 1 and a plurality of tooth rubbers integrally formed on one surface of the back rubber layer 1 are integrated. The back rubber layer 1 of the belt body 3 including the layer 2
A plurality of belt tension members (core wires) 4 are embedded in the toothed member, and tooth cloth 5 is integrally adhered to the tooth surface of the tooth rubber layer 2 with an adhesive (not shown) Belt A can be obtained.

The rubber constituting the belt body of the power transmission belt may be either natural rubber or synthetic rubber,
Although not particularly limited, examples thereof include acrylonitrile-butadiene copolymer rubber, chlorosulfonated polyethylene rubber, hydrogenated nitrile rubber and the like.

As the vulcanization system, any vulcanization system of organic peroxide, metal oxide, and sulfur may be used, and an accelerator may be used. The material is not particularly limited as long as it is conventionally known.

For example, in the case of organic peroxide, di-t-
Butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, α, α′-bis (t-butylperoxy) -p-diisopropylbenzene, 2,
5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyldi (t-butylperoxy)
Hexine-3,2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxyisopropyl carbonate, 1,1-bis (t-butylperoxy) -3,5,5-trimethyl Cyclohexane etc. can be mentioned.

Other vulcanizing agents include vulcanizing agents such as sulfur and triazines, vulcanizing accelerators such as thiazoles, dithiocarbamates, thiurams and thioureas, alkylphenol resins, brominated alkylphenols. Resins and resin vulcanizing agents such as N-N'-m-phenylene dimaleimide may be mentioned.

In addition to the above-mentioned vulcanizing agent, the rubber compounding agent further contains various reinforcing fillers, anti-aging agents, plasticizers, vulcanization aids, processing agents generally known as rubber compounding agents. You may contain appropriate amounts, such as an auxiliary agent.

[0026]

With the above structure, in the first solution of the present invention, in the strand composed of the glass element wire, the hydrophilic component is eluted from the surface layer of the glass element wire by the acid treatment and the hydrogen substitution of the alkali metal is prevented. Then, a water resistant layer is formed on the surface of the glass fiber cord for rubber reinforcement thus produced, the decrease in water absorption rate is suppressed, and breakage due to water resistance deterioration of the glass fiber cord for rubber reinforcement is prevented.

In the third solution of the present invention, the glass fiber cord for rubber reinforcement as described above is embedded in the belt main body so that the waterproof layer on the surface of the cord is formed inside the glass against the attack of moisture when the belt is used. It has a protective function and the life of the belt is significantly improved in the presence of water.

In the second and fourth means for solving the problems of the present invention, since the glass strands forming the strands of the glass fiber cord are acid-treated with hydrochloric acid having a concentration of 0.05 to 0.1N, the above-mentioned hydrochloric acid is used. The glass strands are not adversely affected, the strength of the glass fiber cord is not reduced, water resistance is effectively obtained, and the life of the belt is effectively extended.

[0029]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

A processing code was obtained according to the following procedure.

After melting the E glass and pushing,
Wash with 0.1N hydrochloric acid.

Next, it is washed with water and treated with a sizing agent containing a silane coupling agent as a main component to obtain a filament diameter of 9 μm and a count of 15000.
A strand of 22,500 yards / bond is obtained.

(A) Resorcinol (R) -formalin (F) condensate (R / F mol ratio = 1 / 1.5, solid content 6)
%) Aqueous solution: 100 parts by weight (b) JSR 0650 vinyl pyridine latex: 150 parts by weight (c) water: 25 parts by weight The mixed solution of (a) to (c) is dipped into the strand obtained above.

This dipping-treated strand was heat-treated at 250 ° C. for 1 min and twisted in a predetermined number to obtain a treated cord of this example.

The water absorption of this treated cord was examined in the following manner, and the results are shown in FIG. 3 together with those when the concentration of hydrochloric acid was changed. Further, the tensile breaking strength of the glass filament was examined in the following manner, and the results are shown in FIG. 4 together with those when the concentration of hydrochloric acid was changed.

Further, a toothed belt A as shown in FIG. 1 was produced by using the above-mentioned treated cord as a belt tension member (core wire) 4. Table 1 shows the rubber composition of the belt body 3 (back rubber layer 1, tooth rubber layer 2). Further, a belt bending test was performed using this toothed belt A in the following manner, and the results are shown in FIG. 5 together with those when the hydrochloric acid concentration was changed.

As is clear from FIGS. 3 to 5, 0.05
By washing with ~ 0.1N hydrochloric acid, the water absorption of the treated cord is reduced, and the breaking strength of the glass filament (shown by Δ in Fig. 4) is not affected by this hot water even after immersion in 70 ° C x 1hrs. Compared to the original that is not soaked (marked with a circle in FIG. 4), it is not so much lowered, and further, the belt strength maintenance rate after belt bending fatigue running is also improved.

<Measurement Procedure of Water Absorption of Treatment Code> RFL
The glass fiber cord that had been treated was cut into a length of 5 cm and immersed in warm water at 70 ° C. for 24 hours. The rate of weight change before and after that was taken as the water absorption rate.

<Procedure for Measuring Tensile Breaking Strength of Glass Filament> A filament was taken out from the glass fiber in a strand state and subjected to a tensile test with a tensile tester. The pulling conditions are a pulling speed of 250 mm / min and a chuck gap of 30 mm.

[0040]

[Table 1]

<Procedure of Belt Bending Test> The toothed belt A is shown in FIG. 2 with four large pulleys 11 of the belt bending tester.
Four small pulleys 12 arranged between the large pulleys 11 adjacent to each other
(Diameter 30 mm), the weighted belt A was applied with a tension of 40 kgf with the weight 13, and in a water resistance bending test, the belt was kept running at a flexing frequency of 5 × 10 ⁷ times. I checked. At this time, water was dripped on the tooth bottom of the toothed belt A at a rate of 1 liter per hour.
The toothed belt A used in this test has the structure shown in FIG. 1, the belt width is 19 mm, and the belt body 3 is H.
-NBR and tooth cloth 5 are nylon canvas.

[0042]

As described above, according to the present invention of claim 1, the glass strand is acid-treated before the sizing agent treatment, so that the glass fiber cord surface for rubber reinforcement is formed by this acid treatment. The water-resistant layer can prevent breakage of the glass fiber cord due to water resistance deterioration.

According to the third aspect of the present invention, since the rubber-reinforcing glass fiber cord as described above is embedded in the belt main body, it is possible to remarkably improve the belt life under the condition where water is present.

According to the present invention as set forth in claims 2 and 4, since the concentration of hydrochloric acid as an acid treating agent is set to 0.05 to 0.1 N, water resistance can be effectively obtained and the belt length can be increased. The life can be effectively increased.

[Brief description of drawings]

FIG. 1 is a sectional view of a toothed belt.

FIG. 2 is a configuration diagram of a belt bending tester.

FIG. 3 is a graph showing a relationship between a water absorption rate of a treatment code and a hydrochloric acid concentration.

FIG. 4 is a graph showing the relationship between the tensile breaking strength of glass filaments and the concentration of hydrochloric acid.

FIG. 5 is a graph showing the relationship between belt strength maintenance rate and hydrochloric acid concentration after belt water resistance 8-axis bending fatigue running.

[Explanation of symbols]

 3 Belt body 4 Belt tension body (glass fiber cord) A Toothed belt (transmission belt)

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Claims (4)

[Claims] 1. A glass fiber cord for rubber reinforcement, wherein resorcin-formalin-rubber latex is dipping-treated on a strand made of a glass element wire which has been acid-treated before sizing agent treatment. 2. The glass fiber cord for rubber reinforcement according to claim 1, wherein the acid used for the acid treatment is hydrochloric acid, and the concentration of the hydrochloric acid is 0.05 to 0.1N. 3. A rubber-reinforcing glass fiber cord in which a resorcin-formalin-rubber latex is dipped on a strand made of a glass element wire which has been acid-treated before the sizing agent is embedded in a belt body. A transmission belt characterized by being. 4. The transmission belt according to claim 3, wherein the acid used for the acid treatment is hydrochloric acid, and the concentration of the hydrochloric acid is 0.05 to 0.1N.