JP3030467B2 - Method of bonding hydrogenated nitrile rubber compound to fiber - Google Patents

Description

The present invention relates to a method for bonding a hydrogenated nitrile rubber compound to fibers.

2. Description of the Related Art Hydrogenated nitrile rubber is known as a rubber having both oil resistance and heat resistance. This hydrogenated nitrile rubber is a rubber having improved heat resistance while maintaining oil resistance, which is an advantage of the conventional nitrile rubber. Furthermore, in recent years, hydrogenated nitrile rubbers having improved strength and heat resistance by blending a metal salt of an ethylenically unsaturated carboxylic acid have been developed.

Such hydrogenated nitrile rubber is used in various applications such as hoses, power transmission belts, conveyor belts, tires, industrial rubber products, and the like.
A composite reinforced with a fibrous material, which requires strong adhesion between rubber and fibers.

Conventionally, RFL is generally used as a method of bonding rubber and fiber.
It is well known that fibers are treated in advance with a liquid mixture of resorcinol, formalin, and rubber latex, which is called a liquid, and the fibers are tightly vulcanized with unvulcanized rubber. However, simply treating the fiber material with such a conventional RFL solution cannot achieve strong adhesion between the hydrogenated nitrile rubber and the fiber, which leads to rubber breakage.

Problems to be Solved by the Invention The present invention has been made in order to solve the above-mentioned problems in adhesion between a hydrogenated nitrile rubber compound containing a metal salt of an ethylenically unsaturated carboxylic acid and fibers. Accordingly, it is an object of the present invention to provide a method for bonding a hydrogenated nitrile rubber compound and a fiber, which can achieve strong bonding between the fiber and the fiber.

Means for solving the problems The present invention relates to a method for bonding a hydrogenated nitrile rubber compound containing an ethylenically unsaturated carboxylic acid metal salt and an organic peroxide to a fiber, wherein the fiber material is a urethane-modified epoxy compound. After immersing in a solution containing a curing agent for an epoxy compound, heating and drying, and then immersing in a mixed solution of resorcinol, formalin, and rubber latex, heating,
Next, it is characterized in that it is tightly vulcanized with the hydrogenated nitrile rubber compound.

In the hydrogenated nitrile rubber formulation used in the process according to the invention, the hydrogenated nitrile rubber is preferably
It contains a metal salt of ethylenically unsaturated carboxylic acid and an organic peroxide at a hydrogenation rate in the range of 80 to 99%.

Examples of the ethylenically unsaturated carboxylic acid metal salts include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and 3-butenoic acid, and unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid. And metal salts of these monoesters and the like, and as the metal salt, for example, a zinc salt, a magnesium salt, a calcium salt, an aluminum salt and the like are preferable.

Such metal salts of ethylenically unsaturated carboxylic acids are
Usually, 3 to 100 parts by weight based on 100 parts by weight of the hydrogenated nitrile rubber.
It is blended in the range of parts by weight. When the amount of the metal salt of the ethylenically unsaturated carboxylic acid is less than 3 parts by weight based on 100 parts by weight of the hydrogenated nitrile rubber, the effect of improving the strength of the hydrogenated nitrile rubber is poor. , The strength is also reduced. Particularly preferably, the metal salt of the ethylenically unsaturated carboxylic acid is blended in an amount of 5 to 60 parts by weight based on 100 parts by weight of the hydrogenated nitrile rubber.

A compound obtained by compounding a metal salt of an ethylenically unsaturated carboxylic acid with a hydrogenated nitrile rubber in this manner is commercially available, for example, from Zeon Corporation as a hydrogenated nitrile rubber ZSC. In the method of the present invention, Such commercially available products can be suitably used.

The metal salt of the ethylenically unsaturated carboxylic acid may itself be blended with the hydrogenated nitrile rubber, but also, the hydrogenated nitrile rubber may contain an ethylenically unsaturated carboxylic acid and a metal oxide, hydroxide, Carbonates and the like may be compounded with other rubber chemicals, and a metal salt of an ethylenically unsaturated carboxylic acid may be formed in the hydrogenated nitrile rubber during kneading.

The organic peroxide is not particularly limited as long as it is generally used for peroxide crosslinking of rubber. Accordingly, as such organic peroxides, for example, dicumyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-di (t -Butylperoxy) -hexyne-3,2,5-dimethyl-2,5-
Examples thereof include di (benzoylperoxy) hexane and 2,5-dimethyl-2,5- (t-butylperoxy) hexane.

These organic peroxides are usually compounded in the range of 0.2 to 10 parts by weight with respect to 100 parts by weight of the hydrogenated nitrile rubber, but the optimum amount is determined in consideration of the required physical properties and the like. .

Further, the hydrogenated nitrile rubber compound may, if necessary,
Carbon black, reinforcing agents such as silica, fillers such as calcium carbonate and talc, triallyl isocyanurate,
A conventional rubber chemical such as a crosslinking aid such as trimethylolpropane or a coloring agent may be contained.

According to the method of the present invention, strong adhesion can be achieved between the fibrous materials previously treated according to the present invention by tight vulcanization to such a hydrogenated nitrile rubber compound.

According to the method of the present invention, the fiber material is first treated with a solution containing a urethane-modified epoxy compound and a curing agent for epoxy groups (hereinafter referred to as a treatment solution). This treatment is usually carried out by immersing the fiber material in a treatment solution and then drying by heating.

The urethane-modified epoxy compound is, for example, a compound having an epoxy group at the end of a polyurethane chain, as described in "Plastics", Vol. 23, No. 9, pp. 9-12 (1984). Further, the curing agent generally means a polyamine used for curing an epoxy resin, a polyamide, a polycarboxylic anhydride, a polysulfide, a polymercaptan, a dicyanamide, etc., which undergoes an addition reaction to an epoxy group to cause a crosslinking reaction. . Therefore, those which act as a catalyst to cause ring-opening polymerization of an epoxy group are not included in the curing agent of the present invention.

In the method of the present invention, in the operation of treating the fiber material,
The treatment solution advantageously contains 5 to 20% by weight of the urethane-modified epoxy compound and 5 to 20% by weight of the curing agent, for a total of 10 to 40% by weight, preferably 10 to 30% by weight. After immersing the fiber material in such a solution, the fiber material is usually heated and dried at 100 to 240 ° C for several minutes, depending on the type of the fiber material, the urethane-modified epoxy compound, and the curing agent.
Process fiber material.

Next, according to the method of the present invention, the fiber material is immersed in the RFL solution and heat-treated. The RFL solution usually contains resorcinol and formalin mol at a resorcinol / formalin molar ratio of 1/3 to 3
/ L, preferably in the range of rubber latex solids / solids weight ratio of resorcinol to formalin.
It is preferably in the range of 1/1 to 1/3.

The rubber latex includes acrylonitrile-butadiene copolymer rubber (NBR) latex, carboxylated acrylonitrile-butadiene copolymer rubber (NBR) latex, styrene-butadiene copolymer rubber (SBR) latex, vinylpyridine (Vp) Rubber latex, chloroprene rubber (CR) latex, chlorosulfonated polyethylene rubber latex and the like are used, and NBR latex is particularly preferably used.

After immersion in the RFL solution, the fiber material is typically heated to a temperature in the range of 100-250 ° C for several minutes to fix the resol RFL solution to the fibers.

Further, the fiber material subjected to the above treatment may be coated with a hydrogenated nitrile rubber compound as a glue rubber.

In the method of the present invention, as described above, the fiber material may be treated with the polyisocyanate compound before being treated with the solution containing the urethane-modified epoxy compound and its curing agent.

Examples of the polyisocyanate compound include, but are not particularly limited to, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, hexane triisocyanate, Methylene polyphenyl diisocyanate is preferably used.

Further, a polyhydric alcohol-added polyisocyanate obtained by reacting such a polyisocyanate with a compound having two or more active hydrogens in the molecule, such as trimethylolpropane or pentaerythritol, or a phenol, a tertiary or A blocked polyisocyanate obtained by reacting a blocking agent such as an alcohol or a secondary amine to block an isocyanate group of the polyisocyanate is also suitably used as the polyisocyanate compound.

The treatment of the fiber material with the polyisocyanate compound is performed by heating the fiber material after immersing the fiber material in a solution of the polyisocyanate compound. This heat treatment depends on the type of the fiber material and the polyisocyanate compound to be used, but may be performed at a temperature sufficient to react and fix the polyisocyanate compound attached to the fiber, and is usually treated at 100 to 250 ° C. for several minutes. do it.

By pretreating the fiber material with such a polyisocyanate compound, the fiber is activated by being imparted with a chemically active functional group. Therefore, such a fiber material is treated with an RFL solution. In doing so, it firmly adheres to the fibers and thus forms a strong bond between the fiber material and the hydrogenated nitrile rubber compound.

In the method of the present invention, typical examples of the fiber material include cotton, human silk, polyvinyl alcohol fiber, aliphatic polyamide fiber, aromatic polyamide fiber, polyester fiber, glass fiber, and carbon fiber. ,
It is not particularly limited, and includes all fibers conventionally used for bonding with rubber.

The fiber material treated as described above is then intimately vulcanized with the hydrogenated nitrile rubber compound to achieve strong adhesion between the rubber water compound and the fiber material. The cross-linking conditions may be ordinary conditions known for hydrogenated nitrile rubber compounds, and are appropriately selected depending on the decomposition temperature of the organic peroxide used.

Effect of the Invention As described above, according to the method of the present invention, a method for bonding a hydrogenated nitrile rubber compound containing a metal salt of an ethylenically unsaturated carboxylic acid and an organic peroxide to a fiber material, the fiber material Is treated with a urethane-modified epoxy compound, then treated with an RFL solution, and then tightly vulcanized with the hydrogenated nitrile rubber compound to obtain a conventional RFL.
Strong adhesion that cannot be achieved by the method using a liquid can be obtained.

Further, the urethane-modified epoxy resin has an increased intermolecular force due to a urethane group in the molecule, and is also provided with flexibility, so that compared with the case where the epoxy resin is used as an adhesive, High adhesion, especially high peel strength, is achieved.

Therefore, the method of the present invention is suitable for bonding a fibrous material as a reinforcing member of a hydrogenated nitrile rubber in a dynamic product such as a power transmission belt, a conveyor belt, and a tire. For example, the method of the present invention is suitably used for bonding a cord made of polyester fiber or aramid fiber to a hydrogenated nitrile rubber.

EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

RFL liquid used in the following, resorcin 17 parts by weight,
15 parts by weight of formalin and 10 parts by weight of 13 parts by weight of a sodium hydroxide flexible aqueous solution are dissolved in 224 parts by weight of deionized water, and 30 parts by weight of the obtained solution are mixed with hydrogenated nitrile rubber latex (solid content of 40% by weight). Was added to 38 parts by weight of deionized water.

Example 1 A polyester fiber cord (1500D / 2 × 5) or an aramid fiber cord (1500D / 2 × 3) was converted to a polyisocyanate (Sumijur 44V-2 manufactured by Sumitomo Bayer Urethane Co., Ltd.).
(0, crude MDI) was immersed in a pretreatment solution consisting of 10 parts by weight of toluene and 90 parts by weight of toluene and heat-treated at 235 ° C. for 1 minute.

Next, it is immersed in the treatment liquid A whose composition is shown in Table 1,
Heat treatment was performed at 200 ° C. for 1 minute (hereinafter, this treatment is referred to as first treatment). Thereafter, the fiber material was immersed in the above-mentioned RFL solution, and heat-treated at 200 ° C. for 1 minute (hereinafter, this process is referred to as “second
Processing. ).

50 parts by weight of a hydrogenated nitrile rubber compound (ZSC2295 manufactured by Zeon Corporation) containing 100 parts by weight of zinc methacrylate per 100 parts by weight of hydrogenated nitrile rubber (hydrogenation rate 95%) 50 parts by weight of hydrogenated nitrile rubber (ZETPOL2020 manufactured by Zeon Corporation), silica 10
After arranging in parallel with no gap in the longitudinal direction on a sheet of an unvulcanized hydrogenated nitrile rubber compound consisting of 5 parts by weight and 5 parts by weight of cumyl peroxide (Peroximon F-40 manufactured by NOF Corporation), at 170 ° C. Heat bonding was performed for 30 minutes to obtain an adhesive.

The adhesive was cut to a width of 1 inch in the transverse direction, and the 180 ° peel adhesive force between the fiber cord and the vulcanized rubber was removed by a peeling device 100.
It was measured in mm / min. The results are shown in Table 2.

Examples 2 and 3 In Example 1, the pretreatment of the fiber cord was not performed.
Also, in the first treatment, an adhesive was obtained in the same manner as in Example 1 except that the treatment liquid A or B was used, and the 180 ° peel adhesion between the fiber cord and the vulcanized rubber was measured. The results are shown in Table 2.

Comparative Examples 1-4 The same polyester fiber cords or aramid fiber cords as in Example 1 were subjected to the pretreatment or not, and the first treatment was carried out in the same manner as in Example 1 except that the treatment liquid C or D was used.
The fiber cord was treated in the same manner as described above, and an adhesive was obtained using the same. The 180 ° peel adhesion between the fiber cord and the vulcanized rubber was measured. The results are shown in Table 2.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08J 5 / 12,5 / 06 C09J 5/02 D06M 15 / 55,15 / 693

Claims (2)

(57) [Claims] 1. A method for bonding a hydrogenated nitrile rubber compound containing a metal salt of an ethylenically unsaturated carboxylic acid and an organic peroxide to a fiber material, wherein the fiber material is cured for a urethane-modified epoxy compound and an epoxy compound. After immersing in a treatment solution containing the agent, heating and drying, and then immersing in a mixed solution of resorcinol, formalin, and rubber latex,
A method for bonding a hydrogenated nitrile rubber compound to a fiber, comprising heating and then vulcanizing the mixture with the hydrogenated nitrile rubber compound. 2. A method of bonding a hydrogenated nitrile rubber compound containing a metal salt of an ethylenically unsaturated carboxylic acid and an organic peroxide to a fiber material, wherein the fiber material is immersed in a solution of a polyisocyanate compound, and then heated. Then, the fiber material is immersed in a treatment solution containing a urethane-modified epoxy compound and a curing agent for the epoxy compound, and then heated and dried,
Then, after immersing in a mixed solution of resorcinol, formalin, and rubber latex, heating, and then closely vulcanizing with the hydrogenated nitrile rubber compound, a method of bonding the hydrogenated nitrile rubber compound to fibers. .