JPS6150500B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to compositions for vulcanizing halogen-containing polymers. More particularly, the present invention relates to a vulcanizing composition comprising two components: (a) a halogen-containing polymer, and (b) a metal salt of dimercaptomaleonitrile. polychloroprene, polyepichlorohydrin,
epichlorohydrin-ethylene oxide copolymer, chlorinated acrylic rubber, chlorinated polyethylene,
Halogen-containing polymers such as brominated butyl rubber, fluorocarbon rubber, and polyvinyl chloride are widely used as materials with excellent physical properties such as heat resistance, oil resistance, and chemical resistance when vulcanized. However, since the carbon-halogen bond in the polymer is chemically stable, it has hitherto been difficult to effectively vulcanize it. An object of the present invention is to improve the physical properties of a halogen-containing polymer by easily and effectively vulcanizing the polymer. Examples of halogen-containing polymers that are the object of the present invention include chlorinated polyethylene, chlorinated ethylene-propylene copolymer, chlorinated ethylene-propylene-nonconjugated diene terpolymer, chlorosulfonated polyethylene, polyvinyl chloride, Chlorinated acrylic rubber, chlorinated butyl rubber, brominated butyl rubber, fluorine rubber, polychloroprene, polyepichlorohydrin, epichlorohydrin-allyl glycidyl ether copolymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether ternary copolymer Examples include polymers. The metal salt of dimercaptomaleonitrile used in the present invention is a compound represented by the following general formula. However, in the above general formula, x is 1 or 2. When x=1, M is Ca, Mg, Ba, Zn,
It is a metal selected from Cd and Mn, and when x=2, M is a metal selected from K and Na. The composition of the present invention contains 0.1 to 10 parts by weight, particularly preferably 0.2 to 6 parts by weight, of a metal salt of dimercaptomaleonitrile as component (b) per 100 parts by weight of the halogen-containing polymer as component (a). is appropriate. Further, it is effective to further add a metal compound serving as an acid acceptor to the composition of the present invention from the viewpoint of thermal stability of the halogen-containing polymer. Metal compounds that serve as acid acceptors include oxides, hydroxides, carbonates, carboxylates, and
Silicates, borates, phosphites, periodic table a
These include group metal oxides, basic carbonates, basic carboxylates, basic phosphites, basic sulfites, and tribasic sulfates. Specific examples include magnesia, magnesium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, raw coal, slaked lime, calcium carbonate, calcium silicate, calcium stearate, zinc stearate, calcium phthalate, phosphorous acid. Magnesium, calcium phosphite, zinc white, tin oxide, litharge, red lead, white lead, dibasic lead phthalate, dibasic lead carbonate, tin stearate, basic lead phosphite, basic tin phosphite,
Examples include basic lead sulfite and tribasic lead sulfate. The amount of the metal compound that serves as the acid acceptor is 0.5 parts by weight per 100 parts by weight of the halogen-containing polymer.
A range of from 1 to 50 parts by weight, particularly preferably from 1 to 20 parts by weight, is suitable. Among the halogen-containing polymers targeted by the present invention, polymers with particularly low reactivity include sulfur or thiuram sulfides, dithiocarbamates, sulfenamides, and aliphatic amines.
It is preferable to use amines such as aromatic amines, aldehyde amines, and guanidines, or vulcanization accelerators such as weak acid salts and adducts of amines, or basic silicas. Examples of such particularly low-reactivity halogen-containing polymers include chlorinated polyethylene, polyvinyl chloride, chlorinated butyl rubber, polyepichlorohydrin, epichlorohydrin-allyl glycidyl ether copolymer, and chlorinated acrylic rubber. Specific examples of the above-mentioned vulcanization accelerators include dipentamethylenethiuram tetrasulfide, tetramethylthiuram disulfide, cadmium pentamethylenedithiocarbamate, tellurium dimethyldithiocarbamate, piperidine pentamethylenedithiocarbamate, cyclohexylamine, dibutylamine, Orthotolylguanidine, diphenylguanidine, acetaldehyde-aniline condensate, butyraldehyde-aniline condensate, N-cyclohexyl-2-benzothiazylsulfenamide, N,N-dicyclohexyl-2-benzothiazylsulfenamide, 2 - dicyclohexylamine salt of mercaptobenzothiazole, etc. The appropriate amount of these vulcanization accelerators is 0.2 to 6 parts by weight per 100 parts by weight of the halogen-containing polymer. In order to provide rapid vulcanization and excellent processing stability in the present invention, it is recommended to add thioimide such as N-cyclohexylthiophthalimide, which is commonly used for this purpose as an early vulcanization inhibitor. It is valid. The appropriate amount of addition is 0.1 to 3 parts by weight per 100 parts by weight of the halogen-containing polymer. In addition to the above, the composition of the present invention may optionally contain various fillers, reinforcing agents, plasticizers, processing aids, anti-aging agents, pigments, flame retardants, etc., as commonly practiced in the art. Can be blended. As a method for blending the composition of the present invention, any means conventionally used in the field of polymer processing, such as mixing rolls, Banbury mixers, various kneaders, etc., can be used. The composition of the present invention can be made into a vulcanizate by heating it usually to 100 to 200°C. The vulcanization time varies depending on the temperature, but is usually 0.5 to 300 minutes. As the vulcanization molding method, any method can be used, such as pressure molding using a mold, injection molding, steam can, air bath, or heating using infrared rays, microwaves, or the like. The present invention will be specifically explained below using examples. Examples 1 to 6, Comparative Example 1 Each compound shown in Table 1 was kneaded with an open roll at 60 to 70°C, and the sheet was put into a mold.
Pressure molding was carried out at 155°C and 80 kg/cm ² for 30 minutes. Physical property tests were conducted on each of the obtained vulcanizates, and the results are shown in Tables 2 to 4. Comparative Example 1 is a formulation using 2-mercaptoimidazoline, which has conventionally been used as a vulcanizing agent for epichlorohydrin-ethylene oxide copolymers. In addition, the vulcanization curves of the formulations of Examples 2 and 5 and Comparative Example 1 were measured using a JSR type culastometer at an amplitude angle of 3° and 155°C, and the results are shown in FIG.

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【table】 [Brief explanation of the drawing]

FIG. 1 shows the vulcanization curves of Examples 2 and 5 and Comparative Example 1.

Claims (1)

[Scope of Claims] 1 (a) a halogen-containing polymer (b) a metal salt of dimercaptomaleonitrile represented by the following general formula; Composition for sulfur. However, in the above general formula, x is 1 or 2. When x=1, M is Ca, Mg, Ba, Zn,
It is a metal selected from Cd and Mn, and when x=2, M is a metal selected from K and Na.