JPH043768B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to a method of adhering a rubber compound to fibers. Conventional technology In general, bonding between rubber and fibers has been conventionally performed using
The method used is to treat fibers with a mixture of resorcinol-formalin resin and rubber latex called RFL liquid, and then vulcanize this in close contact with unvulcanized rubber. However, in such a method, in order to achieve adhesion, it is necessary to use a rubber latex of the same type as the rubber in the rubber compound from the viewpoint of compatibility and the like. That is, the latex component to be used is limited depending on the type of rubber. Furthermore, it is also necessary that the latex used has polar groups. That is, if the latex does not have a polar group, there will be no strong interaction between the resorcinol and the formalin resin, making it impossible to achieve the desired adhesion. Therefore, when adhering ethylene-propylene copolymer rubber, hydrogenated nitrile rubber, fluorocarbon rubber, etc. that do not have polar groups, the RFL method cannot be used because these rubbers do not have polar groups in their molecules. In this case, sufficient adhesion with the fibers cannot be achieved. Problems to be Solved by the Invention As a result of intensive research in order to solve the above-mentioned problems in adhesion between rubber compounds and fibers, the present inventors have found that a polyepoxy compound having two or more epoxy groups in the molecule has been developed. After the fibers have been treated, natural rubber and synthetic rubber, especially the above-mentioned hard-to-adhesive We have discovered that strong adhesion with fibers can also be achieved with ethylene-propylene copolymer rubber, hydrogenated nitrile rubber, fluorocarbon rubber, etc., leading to the present invention. Means for Solving the Problems The present invention provides a method for adhering a rubber compound to fibers, in which the fibers are treated with an epoxy compound having two or more epoxy groups in the molecule, and then (a) an organic peroxide; and (b) contains at least one co-crosslinking agent selected from the group consisting of bismaleimide compounds, polyhydric alcohol acrylates, and polyhydric alcohol methacrylates. In the method of the present invention, the polyepoxy compound having two or more epoxy groups in the molecule is not particularly limited, but preferred specific examples include ethylene glycol, glycerin,
Reaction products of polyhydric alcohols such as sorbitol and pentaerythritol, polyalkylene glycols such as polyethylene glycol, and halogen-containing epoxy compounds such as epichlorohydrin, resorcinol, bis(4-hydroxyphenyl) dimethylethane, and phenol formamide. Examples include resins, polyhydric phenols such as resorcinol/formamide resins, and reaction products of phenolic resins and halogen-containing epoxy compounds such as epichlorohydrin. In the method of the present invention, these epoxy resins are usually in solution and the fibers are treated by immersing them in the solution. After this, the fibers are heat treated. This heat treatment may be carried out at a temperature sufficient to react and fix the epoxy compound attached to the fiber, although it depends on the type of fiber used.
It is sufficient to process at 160 to 250°C for several minutes. In the method of the present invention, after drying the fibers treated with the epoxy compound, a carbon-carbon compound having Alfrey and Price's Q value and e value satisfying Q≧0.2 and e≧0, respectively, is used together with an organic peroxide. By intimate vulcanization with an unvulcanized rubber compound containing a co-crosslinking agent having two or more double bonds, strong adhesion can be achieved between the rubber compound and the fibers. However, in the present invention, the conditions for vulcanization adhesion are not particularly limited, and may be any conventional conditions known for each rubber compound. In the method of the present invention, the fibers typically include cotton, human silk, polyvinyl alcohol fiber,
Examples include aliphatic and aromatic polyamide fibers, polyester fibers, carbon fibers, glass fibers, etc., but are not particularly limited, and include all fibers conventionally used for bonding with rubber. Further, the rubber to which the method of the present invention can be applied may be either natural rubber or synthetic rubber as long as it can be crosslinked with organic peroxide, and is not particularly limited. In the method of the present invention, the rubbers used include natural rubber, butadiene rubber, isoprene rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, ethylene-propylene copolymer rubber, and chlorosulfonated polyethylene rubber. , hydrogenated nitrile rubber, urethane rubber, silicone rubber,
Examples include fluoro rubber. The above organic peroxide is not particularly limited and may be any conventionally known one, such as di-t-butyl peroxide, t-butylcumyl 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)hexane-3,2,5-dimethyl-
2,5-di(benzoylperoxy)hexane,
t-Butylperoxyisopropyl carbonate, 1,1-bis(t-butylperoxy)-
Examples include 3,5,5-trimethylcyclohexane. The amount of organic peroxide blended in the unvulcanized rubber compound is at least 0.0005 mol, preferably at least 0.001 mol, per 100 g of rubber. When the amount of organic peroxide blended into the rubber is less than 0.0005 mol per 100 g of rubber, strong adhesion between the rubber compound and the fibers cannot be obtained. However, if the amount of organic peroxide in the rubber compound is too large, the resulting vulcanized rubber may have poor practical physical properties, such as reduced elongation or excessive hardness. , in the present invention, the amount of organic peroxide in the unvulcanized rubber compound is:
Usually, 0.05 mol or less per 100 g of rubber,
Preferably, it is 0.01 mol or less. The Alfrey and Price Q value and e value used in the present invention are Q≧0.2 and e, respectively.
Examples of the co-crosslinking agent having two or more carbon-carbon double bonds satisfying ≧0 include N,N'-methylene-di-p-phenylene bismaleimide, N,
N'-oxy-di-p-phenylenebismaleimide, N,N'-4,4'-benzophenone bismaleimide, N,N'-p-diphenylsulfonemaleimide, N,N'-(3, 3'-dimethyl)methylene-
G-p-phenylene bismaleimide, N,N'-
4,4'-dicyclohexylmethane bismaleimide, N,N'-m-xylene bismaleimide, N,
Bismaleimide compounds such as N'-(3,3'-diethyl)methylene-di-p-phenylenebismaleimide-N,N'-methatolylene dimaleimide, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, triethylene Examples include methacrylates of polyhydric alcohols such as glycol dimethacrylate, acrylates of polyhydric alcohols such as trimethylolpropane triacrylate, ethylene glycol diacrylate, and triethylene glycol diacrylate. The amount of the above co-crosslinking agent in the unvulcanized rubber is:
Although it varies depending on the Q value and e value of the co-crosslinking agent, it is usually at least 0.5 part by weight, preferably at least 1 part by weight, per 100 parts by weight of rubber. When the amount of the co-crosslinking agent is less than the above range, the rubber compound and the fibers cannot be firmly adhered by vulcanization adhesion. In the method of the present invention, the rubber compound may contain vulcanizing agents such as sulfur and triazines in addition to the above-mentioned organic peroxides. Furthermore, in the case of chloroprene rubber, it may contain metal oxides. Furthermore, vulcanization accelerators such as thiazoles, dithiocarbamates, thiurams, and thioureas may be contained. Furthermore, it may contain appropriate amounts of various reinforcing fillers, anti-aging agents, plasticizers, vulcanization aids, processing aids, etc. that are commonly known as rubber compounds. Effects of the Invention As described above, according to the method of the present invention, fibers are treated with an epoxy compound having two or more epoxy groups in the molecule, and the fibers are treated with an organic peroxide and the predetermined co-crosslinking agent. By vulcanizing the fibers in close contact with an unvulcanized rubber compound, strong adhesion can be obtained between the rubber compound and the fibers. In the method of the present invention, although not limited by the adhesion mechanism, the fibers which have been given an epoxy group by treatment with an epoxy compound and the predetermined co-crosslinking agent are contained together with an organic peroxide. By vulcanizing the unvulcanized rubber compound in close contact with the compound, radicals are generated in the rubber by the organic peroxide, and the rubber molecules undergo a radical reaction with the co-crosslinking agent having carbon-carbon unsaturated bonds. At the same time, the epoxy groups on the surface of the fibers and the co-crosslinking agent bond to each other through an anion reaction, and thus it seems that the rubber and fibers are strongly bonded. EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples in any way. Example 1 Each of the treatment solutions A to D shown in Table 1
A 1500D/2 x 3 aromatic polyamide fiber cord (Technora, manufactured by Teijin Ltd.) was immersed and heat treated at 210°C for 1 minute, followed by a sheet of unvulcanized rubber compound 1 having the composition shown in Table 2. After adhesion, heat at 160℃
A bond was obtained by vulcanization for 20 minutes. Regarding this adhesive, the tensile speed was measured using a peel tester.
The 180° peel adhesion between the cord and rubber was measured at 100 mm/min. The results are shown in Table 3. For comparison, this was adhered to a sheet of the same unvulcanized rubber compound 1 as above without treatment with an epoxy compound solution, and then vulcanized at 160°C for 20 minutes.
Obtained adhesive. The results are also shown in Table 3. Example 2 The same fiber cord as in Example 1 was immersed in epoxy compound solution A shown in Table 1, and heated at 210°C for 1 minute.

【table】

【table】

【table】

[Table] After the treatment, the unvulcanized rubber compounds 1 to 4 having the compositions shown in Table 2 and the unvulcanized rubber compounds 5 to 6 having the compositions shown in Table 4 were brought into close contact with the sheets.
A bond was obtained by vulcanization at 160° C. for 20 minutes. The adhesive strength of this adhesive was measured in the same manner as in Example 1. The results are shown in Table 5. From the results shown in Table 5, only the rubber compound containing an organic peroxide and a predetermined co-crosslinking agent was firmly adhered to the fiber cord.

【table】

[Table] Example 3 The same fiber cord as in Example 1 was immersed in epoxy compound solution A shown in Table 1 and heat treated at 210°C for 1 minute. Separately, the same fiber cord as in Example 1 was immersed in the epoxine compound solution A shown in the first example,
After heat treatment at 210°C for 1 minute, immersion in each of RFL liquids E to G having the composition shown in Table 6 was carried out at 230°C.
was heat-treated for 1 minute to fix it on the fiber cord. Each of the fiber cords thus treated was treated with a sheet of unvulcanized rubber compound 1 having the composition shown in Table 2 and an unvulcanized rubber acid having the composition shown in Table 7.

[Table] After adhering Compounds 7 to 10 to a sheet, heat treatment at 160℃ for 20 minutes.
After vulcanization for a minute, a bond was obtained. This adhesive was bonded in the same manner as in Example 1.

【table】

[Table] The adhesion strength was measured. The results are shown in Table 8. From the results shown in Table 8, the fiber cords treated with treatment liquid A strongly adhered to all rubber compounds, but the fiber cords treated with treatment liquids E, F, or G adhered strongly to some rubber compounds. Only the parts were firmly adhered. Example 4 Each of the treatment liquids A or B shown in Table 1
1100D/2×5 polyester fiber cord (Teijin
Co., Ltd.) and heat treated at 210℃ for 1 minute.
After being brought into close contact with a sheet of unvulcanized rubber compound 1 having the composition shown in Table 2, it was vulcanized at 160°C for 20 minutes,
Obtained adhesive.

[Table] The adhesive strength of this adhesive was measured in the same manner as in Example 1. The results are shown in Table 9. According to the method of the present invention, polyester fiber cords were also able to be firmly adhered to the rubber compound.

Claims (1)

[Claims] 1. In a method for adhering a rubber compound to fibers, after treating the fibers with an epoxy compound having two or more epoxy groups in the molecule, (a) organic peroxide, and (b) bis A rubber compound characterized in that it is closely vulcanized with an unvulcanized rubber compound containing at least one co-crosslinking agent selected from the group consisting of a maleimide compound, an acrylate of a polyhydric alcohol, and a methacrylate of a polyhydric alcohol. How to bond with fibers. 2. Claim 1, characterized in that the co-crosslinking agent is ethylene glycol dimethacrylate.
Method for adhering the rubber compound and fiber described in Section 1.