JPH0565533B2 - - 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 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, the desired adhesion cannot be achieved because no strong interaction occurs between the resorcinol and the formalin resin. 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 The present invention was made in order to solve the above-mentioned problems in adhesion between rubber compounds and fibers. - It is an object of the present invention to provide a method for adhering fibers to a rubber compound that can realize strong adhesion to fibers also for propylene copolymer rubber, hydrogenated nitrile rubber, and fluorocarbon rubber. Means for Solving the Problems The first aspect of the present invention is that in a method of adhering a rubber compound to fibers, the fibers are treated with a polyisocyanate compound having two or more isocyanate groups in the molecule, and then the general formula Represented by ZSiX ₃ (wherein, Z represents an organic or inorganic functional group having an amino group, X represents a halogen, alkoxy group, or an acyl group, and the Xs may be the same or different.) After being treated with a silane coupling agent, it contains (a) an organic peroxide and (b) a phenolic resin modified with at least one compound selected from the group consisting of cardol, anacardic acid and cardanol. It is characterized by being vulcanized in close contact with an unvulcanized rubber compound. The second aspect of the present invention is a method for adhering a rubber compound to fibers, in which the fibers are treated with a polyisocyanate compound having two or more isocyanate groups in the molecule, and then the general formula ZSiX ₃ (in the formula, Z represents an organic or inorganic functional group having an amino group; After the treatment, an unvulcanized rubber compound containing (a) an organic peroxide and (b) at least one polyfunctional compound selected from the group consisting of a difunctional or higher functional maleimide compound, an acrylate compound, and a methacrylate compound. It is characterized by vulcanization in close contact with objects. In the method of the present invention, the polyisocyanate compound having two or more isocyanate groups in the molecule is not particularly limited, but preferred specific examples include tolylene diisocyanate, m-phenylene diisocyanate, etc. ,p-
Examples include polyisocyanates such as phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, and triphenylmethane diisocyanate. Furthermore, molecular chains obtained by reacting these polyisocyanates with a compound having two or more active hydrogens in the molecule, such as trimethylolpropane or pentaerythritol, under conditions where the isocyanate group/hydroxyl group molar ratio is greater than 1. Urethane prepolymers whose terminals are isocyanate groups, or the polyisocyanates, for example, phenols such as phenol, thiophenol, cresol, and resorcinol, tertiary alcohols such as t-butanol and t-pentanol, diphenylamine, xylidine, etc. Blocked with aromatic secondary amines, imides such as phthalic acid imide, lactams such as caprolactam and valerolactam, oximes such as acetoxime, methyl ethyl ketoxime, and cyclohexanone oxime, or so-called blocking agents such as sodium sulfite. Blocked polyisocyanates and the like can be mentioned. In the method of the present invention, these polyisocyanate compounds are usually made into a 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 polyisocyanate compound attached to the fibers, although it depends on the type of fiber used, and is usually carried out at 160 to 250° C. for several minutes. According to the invention, the fibers treated with polyisocyanate compounds then have the general formula ZSiX ₃ (where Z represents an organic or inorganic functional group having an amino group and X represents a halogen, an alkoxy group or an acyl group). , X may be the same or different.) Treated with a silane coupling agent represented by: Specific examples of such silane coupling agents include γ-aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, and bis(β-hydroxyethyl)γ-aminopropyltrimethoxysilane. Ethoxysilane, N-(trimethoxysilylpropyl)diethylenetriamine, N-(trimethoxysilylpropyl)urea, carboethoxyethylaminopropyltriethoxysilane, phenylaminopropyltrimethoxysilane, aminophenyltrimethoxysilane, N-( dimethoxymethylsilylpropyl) ethylenediamine, and the like. These silane coupling agents are usually prepared as a solution using water and alcohol as solvents, and the fibers are treated by immersing them in such a solution. According to the first method of the present invention, after drying the fibers treated with the silane coupling agent, at least one substance selected from the group consisting of cardol, anacardic acid and cardanol is added together with an organic peroxide. By intimate vulcanization with an unvulcanized rubber compound containing a modified phenolic resin modified with a seed compound, strong adhesion can be achieved between such a rubber compound and the fibers. However, in the present invention, the conditions for vulcanization adhesion are as follows:
There are no particular limitations, and conventional conditions known for each rubber compound may be used. The organic peroxide used in the present invention is not particularly limited and may be any conventionally known one, such as di-t-butyl peroxide, t-butylcumyl peroxide, Dicumyl peroxide, 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)-3,5,5-trimethylcyclohexane, etc. . The amount of organic peroxide blended in the unvulcanized rubber compound is 0.0005 mol or more, preferably 0.001 mol or more 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 blended in the unvulcanized rubber compound is usually 0.05 mol or less, preferably 0.01 mol or less, per 100 g of rubber. In the present invention, the modified phenolic resin is used as a part of the phenol component in the production of novolac type, resol type or benzyl ether type phenolic resins manufactured from phenols such as cresol and redulucin in addition to phenol.
It means a phenolic resin produced using at least one compound selected from the group consisting of cardol, anacardic acid, and cardanol. Here, cardol, anacardic acid, and cardanol are all phenol compounds having an unsaturated long-chain alkyl group as a substituent obtained from cashew nut kernel liquid. These modified phenolic resins are commercially available as so-called cashew modified phenolic resins, and such commercial products can be preferably used in the present invention. The amount of the modified phenolic resin blended in the unvulcanized rubber is usually 0.5 parts by weight or more, preferably 3 parts by weight or more per 100 parts by weight of rubber. When the amount of modified phenolic resin is less than the above range,
The rubber compound cannot be firmly bonded to the fibers by vulcanization adhesion. However, it is not preferable to blend the modified phenolic resin in an amount exceeding 10 parts by weight per 100 parts by weight of rubber, as this will have a detrimental effect on the physical properties of the rubber. In the second method according to the present invention, at least one polyfunctional compound selected from the group consisting of bifunctional or more functional maleimide compounds, acrylate compounds, and methacrylate compounds is used as a co-crosslinking agent in place of the modified phenolic resin. . Examples of such polyfunctional maleimide compounds include N,N'-methylene-di-p-phenylenebismaleimide, N,N'-oxy-di-
p-phenylene bismaleimide, N, N'-4,
4'-benzophenone bismaleimide, N,N'-p
-Diphenylsulfonemaleimide, N,N'-
(3,3'-dimethyl)methylene-di-p-phenylene bismaleimide, N,N'-4,4'-dicyclohexylmethane bismaleimide, N,N'-m-
Examples include xylene bismaleimide, N,N'-(3,3'-diethyl)methylene-di-p-phenylene bismaleimide, and N,N'-methatoluylene dimaleimide. In addition, as polyfunctional acrylate compounds or methacrylate compounds, methacrylates of polyhydric alcohols such as trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane triacrylate,
Examples include (meth)acrylates of polyhydric alcohols such as ethylene glycol diacrylate and triethylene glycol diacrylate. However, in the present invention, metal salts such as zinc (meth)acrylate are not suitable for use because the nucleophilic reactivity of the (meth)acryloyl group is low. In the present invention, the amount of the polyfunctional compound blended in the unvulcanized rubber is usually 0.5 part by weight or more, preferably 1 part by weight or more per 100 parts by weight of rubber. When the blending amount of the polyfunctional compound is less than the above range, the rubber compound and the fiber cannot be firmly bonded by vulcanization adhesion. However, the above polyfunctional compound is added per 100 parts by weight of rubber.
Blending in an amount exceeding 15 parts by weight is not preferable because it has a detrimental effect on the physical properties of the rubber. In the method of the present invention, the fibers typically include cotton, human silk, polyvinyl alcohol fibers, aliphatic and aromatic polyamide fibers, polyester fibers, carbon fibers, glass fibers, etc., but there are no particular limitations. It includes 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 include natural rubber, butadiene rubber, isobrene rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, ethylene-propylene copolymer rubber, chlorosulfonated polyethylene rubber, Hydrogenated nitrile rubber, urethane rubber, silicone rubber,
Examples include fluoro rubber. 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 a polyisocyanate compound having two or more isocyanate groups in the molecule, and then treated with a predetermined silane coupling agent. This is combined with an organic peroxide, a specified modified phenol resin,
Alternatively, strong adhesion can be obtained between the rubber compound and the fibers by intimate vulcanization with an unvulcanized rubber compound containing a polyfunctional maleimide compound or (meth)acrylate compound. 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 A polyester fiber cord (1100d/2×5) was immersed in treatment liquid A shown in Table 1, heat treated at 230°C for 1 minute, and then treated with treatment liquid B, C or D shown in Table 1.
The cord was immersed in water and heat treated at 100°C for 1 minute to obtain an adhesive-treated cord. After these cords were arranged in parallel, they were brought into close contact with a sheet consisting of unvulcanized rubber compounds 1 to 5 having the compositions shown in Table 2, and vulcanized at 160° C. for 20 minutes to obtain an adhesive.

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[Table] Regarding this adhesive, the tensile speed was measured using a peel tester.
Adhesive force was measured at 100 mm/min. The results are shown in Table 4.

[Table] Comparative Example 1 The same polyester fiber cord as in Example 1 was treated with treatment liquid A in the same manner as in Example 1, and then treated with treatment liquid B to obtain an adhesive-treated cord. After these cords were arranged in parallel, they were brought into close contact with a sheet consisting of unvulcanized rubber compounds 6 to 12 having the compositions shown in Table 2, and vulcanized at 160° C. for 20 minutes to obtain an adhesive. Regarding this adhesive, the tensile speed was measured using a peel tester.
Adhesive force was measured at 100 mm/min. The results are shown in Table 5. Example 2 Using the same adhesive treatment cord as in Comparative Example 1, it was brought into close contact with a sheet consisting of unvulcanized rubber compounds 13 to 16 shown in Table 3, and vulcanized at 160°C for 20 minutes to obtain an adhesive. . Regarding this adhesive, the tensile speed was measured using a peel tester.
Adhesive force was measured at 100 mm/min. The results are shown in Table 5.

【table】

【table】

Claims (1)

[Claims] 1. In a method for adhering a rubber compound to fibers, the fibers are treated with a polyisocyanate compound having two _or more isocyanate groups in the molecule, and then treated with a silane coupling agent represented by and an unvulcanized rubber compound containing (a) an organic peroxide and (b) a modified phenolic resin modified with at least one compound selected from the group consisting of cardol, anacardic acid, and cardanol. A method of adhering a rubber compound and fibers, which is characterized by intimate vulcanization. 2. The method of bonding a rubber compound and fibers according to claim 1, wherein the unvulcanized rubber compound contains 0.0005 to 0.05 mol of organic peroxide per 100 g of rubber. 3. The method of bonding a rubber compound and fibers according to claim 1, wherein the unvulcanized rubber compound contains 0.5 parts by weight or more of a modified phenolic resin per 100 parts by weight of rubber. 4. In the method of adhering a rubber compound and fibers, the fibers are treated with a polyisocyanate compound having two or more isocyanate groups in the molecule, and then the general formula ZSiX ₃ (wherein Z is an organic or represents an inorganic functional group, X represents a halogen, an alkoxy group, or an acyl group, and X may be the same or different. (b) contact vulcanization with an unvulcanized rubber compound containing a peroxide and (b) at least one polyfunctional compound selected from the group consisting of bifunctional or higher functional maleimide compounds, acrylate compounds, and methacrylate compounds; Characteristic method of bonding rubber compounds and fibers. 5. The method of bonding a rubber compound and fibers according to claim 1, wherein the unvulcanized rubber compound contains 0.0005 to 0.05 mol of organic peroxide per 100 g of rubber. 6 The unvulcanized rubber compound is based on 100 parts by weight of rubber,
2. The method of adhering a rubber compound and fibers according to claim 1, wherein the polyfunctional compound is contained in an amount of 0.5 parts by weight or more.