JPH0721128B2 - Method of bonding rubber compound and fiber - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to a method for adhering rubber compounds to fibers, and more particularly to a method for strongly adhering highly saturated or fully saturated rubber to fibers.

2. Description of the Related Art In recent years, for example, in the technical field of automobiles, the performance of engines has been remarkably improved, and along with this, the ambient temperature around the engine has risen remarkably as compared with the prior art. Therefore, as a transmission belt around the engine, the main chain is highly saturated or completely saturated, such as hydrogenated nitrile rubber, chlorosulfonated polyethylene rubber, and fluorine rubber, which have excellent heat resistance. The use of existing rubber has been studied, and various methods for adhering such rubber and fibers have already been proposed.

Generally, for the adhesion of rubber and fiber, a method of treating the fiber with a mixture of resorcin-formalin resin and rubber latex, which is called RFL liquid, and closely vulcanizing it with unvulcanized rubber has been conventionally adopted. Therefore, for example, regarding the adhesion between hydrogenated nitrile rubber and fiber, Japanese Patent Publication No. 60-2413.
As described in JP-A-61-207442 and JP-A-61-207442, a method of treating a fiber with an RFL liquid composed of carboxylated NBR latex or halogen-containing polymer latex has been proposed, and chlorosulfonated polyethylene rubber. As described in JP-A-61-127739, a method of treating the fibers and the fibers with an RFL solution composed of NBR latex or carboxylated NBR latex has been proposed.
Also, regarding the adhesion between fluorocarbon rubber and fibers, see Japanese Patent Laid-Open No.
As described in JP-A-11131, a method of treating with an RFL liquid composed of NBR latex or acrylate latex has been proposed.

However, in the adhesion between rubber and fiber using the RFL liquid, in order to achieve excellent adhesion, it is necessary to use the same rubber latex as the rubber in the rubber compound from the viewpoint of compatibility and the like. In any of the above-mentioned methods, strong adhesion between the rubber and the fiber cannot be achieved because the rubber and the rubber type of the latex in the RFL liquid are different.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The inventors of the present invention have conducted extensive studies in order to solve the above-mentioned problems in the adhesion between a rubber compound and a fiber, and as a result, have found that polyepoxy compounds having two or more epoxy groups in the molecule are not compatible with each other. By treating the fiber with a saturated dicarboxylic acid (or an anhydride thereof) and then adhesively vulcanizing it with an unvulcanized rubber compound containing an organic peroxide, natural rubber as well as synthetic rubber, in particular, With respect to highly saturated or fully saturated rubbers such as hydrogenated nitrile rubber, chlorosulfonated polyethylene rubber and fluorine rubber, it was found that strong adhesion with fibers can be realized, and the present invention was achieved. is there.

Means for Solving the Problems The present invention relates to a method for adhering a rubber compound and fibers, and a method for adhering a rubber compound and fibers, wherein (a) an epoxy compound having two or more epoxy groups in the molecule, and (B) The fiber is treated with an unsaturated dicarboxylic acid or an anhydride thereof, and then is closely vulcanized with an unvulcanized rubber compound containing an organic peroxide.

In the method of the present invention, polyepoxy compounds having two or more epoxy groups in the molecule include polyhydric alcohols such as ethylene glycol, glycerin, sorbitol and pentaerythritol, polyalkylene glycols such as polyethylene glycol and epichlorohydrin. Reaction products with halogen-containing epoxy compounds, polyhydric phenols such as resorcin, bis (4-hydroxyphenyl) dimethylethane, phenol-formamide resin, resorcin-formamide resin, and halogen-containing epoxy such as phenol resin and epichlorohydrin Reaction products with compounds are preferably used.

The unsaturated dicarboxylic acids or their anhydrides used in the method of the present invention are not particularly limited, but preferred specific examples include maleic anhydride,
Examples thereof include fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, nadic acid anhydride, chloromaleic acid and hettic acid.

In the method of the present invention, the polyepoxy compound and the unsaturated dicarboxylic acid or the anhydride thereof are usually made into a solution containing them, and the fiber is treated by dipping in the solution. In such a treatment liquid, the compounding ratio of the polyepoxy compound and the unsaturated dicarboxylic acid or the anhydride thereof is
The number of moles of epoxy groups / the number of moles of carboxyl groups of the polyepoxy compound is in the range of 1/4 to 4/1, preferably 2/1 to 1/2. When the compounding ratio of the polyepoxy compound to the unsaturated dicarboxylic acid or its anhydride in the treatment liquid is out of the above range, strong adhesion cannot be obtained between the rubber and the fiber. When an acid anhydride is used, the acid anhydride group is counted as 2 mol of the carboxyl group in the above mixing ratio.

In this way, the fibers are immersed in the solution containing the polyepoxy compound and the unsaturated dicarboxylic acid or the anhydride thereof, and then the fibers are heat-treated. This heat treatment may be carried out at a temperature sufficient to cause reaction fixing of the epoxy compound and unsaturated dicarboxylic acid or its anhydride attached to the fiber, depending on the type of fiber used, usually at 160 to 250 ° C. It can be done for a few minutes.

In the treatment, when an isocyanate compound or a blocked polyisocyanate compound is used instead of the polyepoxy compound, the reactivity with the unsaturated dicarboxylic acid or its anhydride is too high, and the pot life of the treatment liquid is short,
Practicality is poor.

However, in the method of the present invention, the fiber and the rubber are obtained by pretreating the fiber with the polyisocyanate compound or the polyepoxy compound and then treating the polyepoxy compound with the unsaturated dicarboxylic acid or the anhydride thereof. A stronger bond can be achieved between and.
In particular, this pretreatment is effective in achieving a stronger bond between the surface-inert fibers such as aromatic polyamide fibers and polyester fibers and the rubber.

As the isocyanate compound used in this pretreatment, for example, polyisocyanates such as tolylene diisocyanate, metaphenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and polymethylene polyphenyl diisocyanate are preferably used. In addition, 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 and pentaerythritol, and the polyisocyanate with phenols and tertiary A blocked polyisocyanate obtained by reacting a blocking agent such as alcohols and secondary amines to block the isocyanate group of polyisocyanate is also suitably used as the polyisocyanate compound.

Further, as the polyepoxy compound used in the pretreatment, as described above, by reacting a polyhydric alcohol, polyalkylene glycol, polyhydric phenol, a phenol resin or the like with a halogen-containing epoxy compound such as epichlorohydrin The resulting polyepoxy compound is preferably used.

As described above, the pretreatment of the fiber with the polyisocyanate compound or the epoxy compound is usually carried out by treating the polyisocyanate compound or the polyepoxy compound as a solution containing them, and immersing the fiber in the solution and then heat-treating the fiber. It is done. The heat treatment in this pretreatment also depends on the type of fiber used, but it may be carried out at a temperature sufficient for the reaction fixing of the polyisocyanate compound or polyepoxy compound attached to the fiber, and usually 160
It suffices to treat at ~ 250 ° C for several minutes.

In the method of the present invention, as described above, preferably,
After pretreating the fiber with a polyisocyanate compound or polyepoxy compound, it is treated with a polyepoxy compound and unsaturated dicarboxylic acid or its anhydride, and then adheres to an unvulcanized rubber compound containing an organic peroxide. By vulcanizing, a strong bond between the rubber compound and the fibers can be achieved. However, in the present invention, the conditions for vulcanization adhesion are not particularly limited, and may be the usual conditions known for each rubber compound.

In the method of the present invention, as the fiber, typically,
Examples thereof include cotton, polyvinyl alcohol fiber, aliphatic and aromatic polyamide fiber, polyester fiber, carbon fiber, glass fiber, etc., but are not particularly limited, and all fibers conventionally used for adhesion with rubber. including.

Further, the rubber to which the method of the present invention can be applied may be either a natural rubber or a synthetic rubber, as long as it is a rubber capable of being crosslinked with an organic peroxide, and is not particularly limited, but, in particular, In the method of the present invention, as rubber,
Natural rubber, butadiene rubber, isoprene rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, ethylene-propylene copolymer rubber, chlorosulfonated polyethylene rubber, hydrogenated nitrile rubber, urethane rubber, silicone rubber, Fluorine rubber can be used.

The organic peroxide is not particularly limited and may be any conventionally known one, for example, di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide. Oxide, α, α'-
Bis (t-butylperoxy) -p-diisopropylbenzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyldi (t-butylperoxy) hexyne-3, 2,5-Dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxyisopropyl carbonate, 1,1-bis (t-butylperoxy) -3,5,5-trimethylcyclohexane and the like can be mentioned. be able to.

The amount of the organic peroxide compounded in the unvulcanized rubber compound is 0.0005 mol or more, preferably 0.001 mol or more, based on 100 g of the rubber. The amount of organic peroxide compounded into rubber is 100 g of rubber.
On the other hand, when the amount is less than 0.0005 mol, a strong bond cannot be obtained between the rubber compound and the fiber. However, when the blending amount of the organic peroxide in the rubber blend is too large, the vulcanized rubber obtained becomes inferior in practical physical properties, for example, the elongation decreases, or the hardness excessively increases. In the present invention, the compounding amount of the organic peroxide in the unvulcanized rubber compound is usually 0.05 mol or less, preferably 0.02 mol or less, relative to 100 g of the rubber.

In the method of the present invention, the rubber compound, in addition to the organic peroxides described above, sulfur, vulcanizing agents such as triazines,
Thiazoles, dithiocarbamates, thiurams,
A vulcanization accelerator such as thioureas may be contained. Further, it may contain appropriate amounts of various reinforcing fillers, antioxidants, plasticizers, vulcanization aids, processing aids and the like which are generally known as rubber compounds.

Effects of the Invention As described above, according to the method of the present invention, a fiber is treated with an epoxy compound having two or more epoxy groups in the molecule and an unsaturated dicarboxylic acid or an anhydride thereof, and the fiber is treated with an organic peroxide. By adhesion-vulcanizing with an unvulcanized rubber compound containing the rubber, strong adhesion can be obtained between the rubber compound and the fiber.

In the method of the present invention, the epoxy group is imparted to the fiber by treatment with an epoxy compound and an unsaturated dicarboxylic acid or an anhydride thereof, although the epoxy group is not limited by the adhesion mechanism. The unsaturated dicarboxylic acid or the anhydride thereof is fixed to the fiber through or without, and thus the fiber has a high radical-reactive carbon-carbon dicarbonate derived from the unsaturated dicarboxylic acid or the anhydride. Since a heavy bond is imparted, when the fiber is adhered and vulcanized with an unvulcanized rubber compound containing an organic peroxide, a radical is generated in the rubber due to the organic peroxide, and the radical is the fiber. It is believed to bond with the carbon-carbon double bond above to firmly bond the rubber and fiber.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. There is no.

Example 1 A 1260D / 2 × 4 nylon 6 fiber cord was immersed in each of the treatment liquids A to D shown in Table 1 and then heat treated at 180 ° C. for 2 minutes. Then, the sheet was made to adhere to the sheets of unvulcanized rubber compounds 1 to 3 having the composition shown in Table 2 and then vulcanized at 160 ° C. for 20 minutes to obtain an adhesive.

The 180 ° peeling adhesive force between the fiber cord and the rubber of this adhesive was measured with a peeling tester at a peeling speed of 100 mm / min. The results are shown in Table 3.

Example 2 1500 D / 2 × for each of the pretreatment liquids a and b shown in Table 4
The aromatic polyamide fiber cord No. 3 (Tectora manufactured by Teijin Ltd.) was dipped, then heat-treated at 210 ° C. for 1 minute, then dipped in the treatment liquid A shown in Table 1, and then heat-treated at 230 ° C. for 1 minute. . After that, this treatment cord was brought into close contact with the sheet of unvulcanized rubber compound 1 shown in Table 2 and then treated at 160 ° C. for 2 minutes.
It was vulcanized for 0 minutes to obtain an adhesive.

The 180 ° peeling adhesive force between the fiber cord and the rubber of this adhesive was measured with a peeling tester at a peeling speed of 100 mm / min. The results are shown in Table 5.

For comparison, except that the fiber cord is not pretreated
After treating the fiber cord with the treatment liquid A in the same manner as described above, the fiber cord was adhered to the sheet of the unvulcanized rubber compound 1 shown in Table 2 and vulcanized at 160 ° C. for 20 minutes to obtain an adhesive. . The 180 ° peeling adhesive force between the fiber cord and the rubber of this adhesive was measured with a peeling tester at a peeling speed of 100 mm / min. The results are also shown in Table 5.

According to the present invention, the fiber cord can be more strongly adhered to the rubber by pretreating the fiber cord with an epoxy compound or an isocyanate compound.

Example 3 1100D / 2 × 5 polyester fiber cord was dipped in treatment liquid a shown in Table 4 and then heat treated at 210 ° C. for 1 minute, and then the fiber cord was treated with treatment liquid A shown in Table 1 and a comparative example. In Table 6 as After being immersed in each of the treatment liquids E to G shown in the drawing, heat treatment was performed at 230 ° C. for 1 minute. In this way, the treated fiber cord is
After being brought into close contact with the sheets of unvulcanized rubber compounds 4 and 5 having the compositions shown in the table, each was vulcanized at 160 ° C. for 20 minutes,
An adhesive was obtained.

The adhesive strength of this adhesive was measured in the same manner as in Example 1. The results are shown in Table 8. Of the present invention According to the method, the polyester fiber cord could be firmly adhered to the rubber compound. But RF
With L treatment, sufficient adhesion could not be obtained.

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Claims (2)

[Claims] 1. A method for adhering a rubber compound to a fiber, which comprises treating the fiber with (a) an epoxy compound having two or more epoxy groups in the molecule, and (b) an unsaturated dicarboxylic acid or an anhydride thereof. A method for adhering a rubber compound and a fiber, which comprises closely vulcanizing an unvulcanized rubber compound containing an organic peroxide. 2. A method for adhering a rubber compound and a fiber,
The fiber is treated with an isocyanate compound or an epoxy compound, and then (a) an epoxy compound having two or more epoxy groups in the molecule, and (b) an unsaturated dicarboxylic acid or an anhydride thereof, followed by organic treatment. A method for adhering a rubber compound and a fiber, which comprises performing intimate vulcanization with an unvulcanized rubber compound containing a peroxide.