JPH07138879A - Fiber cord for rubber reinforcement and transmission belt using the fiber cord - Google Patents

Abstract

PURPOSE:To improve wettability and adhesivity to a glass surface, prevent the break of a glass fiber cord by reducing water susceptibility of an adhesive layer and largely extend the life of a belt. CONSTITUTION:Glass fiber cord (a tensile resistant member for belt) 4 treated in a treating liquid prepared by dissolving a hydrogenated nitrile rubber (H-NBR) and a kneaded body mainly containing a methylene donor and a methylene acceptor which form a resorcin resin in an organic solvent, is embodied in a main body 3 of a belt.

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 physical properties such as heat resistance, water resistance and bending fatigue 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, the adhesive layer of the fiber cord, which is a belt tension member, is broken, or the interface between the fiber cord and the adhesive is broken, and the fiber cord is broken. As a result, there are many cases where the belt is cut. The causes of this are cracks in the adhesive layer due to repeated tensile and compressive stress applied to the belt, cracks in the adhesive layer due to hardening deterioration of the adhesive under high temperature conditions, water swelling of adhesive under high humidity conditions, tears, and interface with fibers. It may be destroyed.

Therefore, in order to increase the service life of the toothed belt under severe conditions, improvement of physical properties such as bending fatigue resistance, heat resistance and water resistance of the adhesive layer is an important factor.

By the way, when the glass fiber cord is used as the belt tension member, the conventional rubber compound constituting the belt main body and the glass fiber cord are adhered to each other by RFL liquid (resorcin-formalin (RF) condensate and rubber). It is carried out by treating a glass fiber cord with a latex (L) mixture and closely vulcanizing it with an unvulcanized rubber compound (see JP-A-63-270877).

[0006]

However, the RFL
Since it is water-based, it is inferior in water resistance to solvent-based adhesives. Further, since the latex is used, microscopic voids are generated in the adhesive layer, and water is accumulated in these voids, which reduces the water resistance.

By the way, the vulcanization of the rubber constituting the belt main body is made of an organic peroxide (P) in order to improve the heat resistance of the belt.
O) Although it has been transferred to vulcanization, RFL is cured by the influence of this organic peroxide and the flex fatigue resistance is deteriorated.

On the other hand, a method using a solvent-based adhesive has been developed to improve belt performance. Although this method is superior to RFL in water resistance of the adhesive alone, it is inferior to RFL in wettability and adhesiveness to the glass surface, and therefore, in terms of belt performance, it is better than a belt using RFL. Inferior. Therefore, it is not preferable to apply the solvent-based adhesive alone to the glass fiber cord.

There is also a direct vulcanization adhesion method (so-called HRH method) in which a methylene donor and a methylene acceptor are blended with a vulcanizable rubber and the fibers are adhered to each other when the rubber is vulcanized. And when using organic fibers,
Moreover, since it is added to the rubber, it cannot penetrate into the inside of the filament, and the filament inside remains exposed. Therefore, in the glass fiber cord, the damage caused by the friction between the filaments becomes severe, and the fatigue property is poor, and it is not preferable to apply the glass fiber cord to the glass fiber cord.

That is, up to now, no treatment agent has been obtained which satisfies all of the wettability with the glass surface, the adhesiveness, the water resistance and the bending fatigue resistance.

The present invention has been made in view of the above points, and an object thereof is to employ a solvent-type treating agent in place of RFL which is an aqueous type, and to specify the composition thereof to obtain glass. Improves the wettability and adhesiveness to the surface, reduces the water absorption of the adhesive layer, and improves the heat resistance, water resistance and flex fatigue resistance when used as a tensile member of a power transmission belt It is to prevent the cord from being damaged and to greatly improve the belt life.

[0012]

In order to achieve the above object, a first solution of the present invention is to provide a hydrogenated nitrile rubber (H-NBR) and a methylene donor and a methylene donor which are resorcin-based resin forming components. It is characterized in that the glass fiber cord for rubber reinforcement is treated with a treatment liquid prepared by dissolving a kneaded material containing a receptor as a main component in an organic solvent.

A second solving means of the present invention is characterized in that, in the first solving means, the solid content concentration of the treatment liquid is set to 3 to 5 wt%.

A third solution of the present invention is to use a kneaded product containing hydrogenated nitrile rubber (H-NBR) and a methylene donor and a methylene acceptor, which are resorcin-based resin forming components, as main components in an organic solvent. It is characterized in that a glass fiber cord for rubber reinforcement treated with a treatment liquid obtained by melting is embedded in the belt body.

A fourth solution means of the present invention is characterized in that, in the third solution means, the solid content concentration of the treatment liquid is set to 3 to 5 wt%.

The hydrogenated nitrile rubber (H-NBR) polymer used in the present invention is obtained by hydrogenating a conjugated diene unit portion of an unsaturated nitrile-conjugated diene copolymer rubber;
Unsaturated nitrile-conjugated diene-ethylenically unsaturated monomer three-dimensional copolymer rubber or unsaturated nitrile-ethylenically unsaturated monomer copolymer rubber obtained by hydrogenating the conjugated diene unit (COOH-H-NBR ). In the unsaturated nitrile-ethylenically unsaturated monomer copolymer rubber,
A part of the unsaturated monomer may be replaced with a non-conjugated diene such as vinyl norbornene, dicyclopentadiene or 1,4-hexadiene and copolymerized.

These H-NBRs are specifically butadiene-acrylonitrile copolymer rubbers, isoprene-butadiene-acrylonitrile copolymer rubbers, isoprene-acrylonitrile copolymer rubbers hydrogenated; butadiene-methyl acrylate-acrylonitrile copolymers. Polymerized rubber, butadiene-acrylic acid-acrylonitrile copolymer rubber and the like and hydrogenated products thereof; butadiene-ethylene-acrylonitrile copolymer rubber, butyl acrylate-ethoxyethyl acrylate-vinyl chloroacetate-acrylonitrile copolymer rubber, butyl acrylate-ethoxy. Examples thereof include ethyl acrylate-vinyl norbornene-acrylonitrile copolymer rubber and the like, which can be obtained by using an ordinary polymerization method and an ordinary hydrogenation method.

Examples of the methylene donor that is a resorcin-based resin forming component used in the present invention include hexamethylenetetramine, polyvalent methylmelamine derivatives, oxazolidine derivatives, polyvalent methylolacetylene urea and the like.

As the methylene acceptor, resorcin, resorcin-aldehyde condensate, resorcin-alkyl,
Allyl, aralkylphenol-aldehyde co-condensate,
Resorcin-based compounds such as a mixture of a resorcin-aldehyde condensate and an alkyl, allyl, aralkylphenol-aldehyde condensate, a mixture of a resorcin and a fatty acid,
m-Cresol-aldehyde condensate, m-substituted alkylphenol compounds such as m-ethylphenol-aldehyde, methylresorcin, ethylresorcin, propylresorcin, methylresorcin-aldehyde condensate, ethylresorcin-aldehyde condensate, propylresorcin-aldehyde condensation Examples thereof include, but are not particularly limited to.

When blending these three materials, H-N
A BR polymer is kneaded with a methylene donor and a methylene acceptor in advance, and this is dissolved in an organic solvent. As a kneading method, a Banbury, a roll or the like which is generally used as a rubber kneader may be used. The blending ratio (parts by weight) is H-NBR: methylene acceptor: methylene donor = 100: 1.0: 0.5-10.
The range of 0: 10: 8 is most preferable.

In addition to these components, as a general rubber compounding agent, an inorganic filler such as a silicic acid compound, a reinforcing agent such as carbon black, a softening agent, a tackifier, an antiaging agent, etc. may be added as required. It can be added.

The organic solvent for dissolving them is not particularly limited, but methyl ethyl ketone (MEK) is preferable, and the solid content concentration after dissolution is preferably 3 to 5 wt%.
When the solid content concentration is set to 3 to 5 wt%, if it exceeds 5 wt%, it is difficult to impregnate the inside of the filament and the friction between the filaments cannot be prevented, and the glass fiber cord is used as a tensile member of the transmission belt. This is because the belt life will not be extended when used. On the other hand, when the solid content concentration is less than 3 wt%, the adhesion amount is small and the effect of preventing friction between filaments is small and the belt life is shortened.

The glass fiber cord used in the present invention is
The monomer is not particularly limited as long as it is used as a tensile member of a transmission belt, and examples thereof include those commonly referred to as E glass and S glass.

Then, the glass fiber cord is treated with the treatment liquid as described above. When the treated glass fiber cord is used as a belt tension member, it is embedded in the belt main body to form a transmission belt. Composed.

The rubber constituting the belt main body of the power transmission belt may be either natural rubber or synthetic rubber, and is not particularly limited. For example, hydrogenated nitrile rubber, chlorosulphonated polyethylene rubber, etc. Is mentioned.

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, dithiocarbamate salts, 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 compound is further composed of various reinforcing fillers, antioxidants, plasticizers, vulcanization aids, processing agents, which are generally known as rubber compounds. You may contain appropriate amounts, such as an auxiliary agent.

To treat the glass fiber cord for rubber reinforcement with the above treatment agent, a usual dipping method may be used. Further, by performing this treatment before the final twisting of the glass fiber cord, more uniform impregnation and coating between the filaments are achieved.

Then, the glass fiber cord is treated with the above-mentioned treatment liquid and is vulcanized and adhered to the rubber layer as a belt tension member, so that the back rubber layer 1 and the back rubber layer are formed as shown in FIG. 1. A plurality of belt tension members (core wires) 4 are embedded in the back rubber layer 1 of the belt main body 3 composed of a plurality of tooth rubber layers 2 integrally formed on one surface of the tooth rubber layer 2. It is possible to obtain a toothed belt A as a transmission belt in which the tooth cloth 5 is integrally bonded to the tooth surface with an adhesive (not shown).

[0032]

With the above structure, in the first solution of the present invention, a kneading mixture containing hydrogenated nitrile rubber (H-NBR) and a methylene donor and a methylene acceptor as resorcin-based resin forming components as main components. By treating with a treatment liquid made by dissolving the substance in an organic solvent, the wettability and adhesion to the glass surface are improved and the water absorption of the adhesive layer is reduced, bending fatigue resistance, heat resistance and water resistance A glass fiber cord satisfying all of the above is obtained.

In the third solution of the present invention, the glass fiber cord as described above is embedded in the belt main body, so that the glass fiber cord is prevented from being damaged and the belt life is greatly improved.

In the second and fourth means for solving the problems of the present invention, since the glass fiber cord is treated with the treatment liquid having a solid content concentration of 3 to 5 wt% as described above, the treatment liquid is sufficiently impregnated between the filaments, Friction between filaments can be effectively prevented, and the life of the belt can be effectively extended.

[0035]

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

Glass fiber strands (filament diameter 9 μm, count 15000 to 2250) were prepared using the treatment liquids shown in Table 1.
(0 yard / pound) was subjected to a dip treatment, and 11 pieces obtained by aligning 3 pieces were collected and twisted to obtain a treated cord. The processing condition is 250 ° C. × 2.5 min. Using this glass fiber cord as a belt tension member (core wire) 4, a toothed belt A as shown in FIG. 1 was produced. Table 2 shows the rubber composition of the belt body 3 (back rubber layer 1, tooth rubber layer 2). Further, using this toothed belt A, an adhesive force was measured and a belt bending test was conducted in the following manner, and the data is shown in Table 1.

As is apparent from Table 1, it is understood that the treatment according to the present invention increases the adhesive force and extends the belt life as compared with the conventional RFL method.

[0038]

[Table 1]

<Adhesive force measurement procedure> The adhesive force when the belt tension member (core wire) 4 is pulled out from the toothed belt A,
It conformed to the JIS standard.

<Procedure for 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.
Also, in the heat aging bending test, heat aging conditions 150 ° C. × 168
After heat aging for hrs, the belt was allowed to bend at 1 × 10 ⁸ times, and then the belt strength retention rate was examined. The toothed belt A used in this test has the structure shown in FIG. 1, the belt width is 19 mm, the belt body 3 is H-NBR,
The tooth cloth 5 is nylon canvas.

[0041]

[Table 2]

[0042]

As described above, according to the present invention of claim 1, hydrogenated nitrile rubber (H-NBR),
Since the glass fiber cord was treated with a treatment liquid obtained by dissolving a kneaded material mainly containing a methylene donor and a methylene acceptor, which are resorcin-based resin-forming components, in an organic solvent,
It is possible to obtain a glass fiber cord which can improve wettability and adhesiveness to a glass surface, can reduce the water absorption of an adhesive layer, and satisfy all of bending fatigue resistance, heat resistance and water resistance. it can.

According to the third aspect of the present invention, since the glass fiber cord as described above is embedded in the belt main body, it is possible to prevent the glass fiber cord from being damaged and to greatly improve the belt life. .

According to the second and fourth aspects of the present invention, the glass fiber cord is treated with the treatment liquid having a solid content concentration of 3 to 5 wt%, so that the treatment liquid can be sufficiently impregnated between the filaments. Friction between the belts can be effectively prevented, and the life of the belt can be effectively extended.

[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.

[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 treatment liquid prepared by dissolving a kneaded material containing hydrogenated nitrile rubber and a methylene donor and a methylene acceptor, which are resorcin-based resin forming components, as main components in an organic solvent. A glass fiber cord for rubber reinforcement. 2. The glass fiber cord for rubber reinforcement according to claim 1, wherein the treatment liquid has a solid content concentration of 3 to 5 wt%. 3. A rubber-reinforcing glass treated with a treatment liquid obtained by dissolving a kneaded material containing hydrogenated nitrile rubber and a methylene donor and a methylene acceptor, which are resorcin-based resin-forming components, as main components in an organic solvent. A transmission belt having a fiber cord embedded in the belt body. 4. The transmission belt according to claim 3, wherein the treatment liquid has a solid content concentration of 3 to 5 wt%.