JPS6054975B2 - Method for suppressing early vulcanization of halogen-containing polymers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for vulcanizing a halogen-containing polymer using 2,3-dimercaptopyrazine or 2,3-dimercaptoquinoxaline or a derivative thereof. The present invention relates to a method for inhibiting early vulcanization of a halogen-containing polymer, which is characterized by the presence of a sulfonamide.

The present applicant has previously provided a composition for vulcanizing a halogen-containing polymer containing a vulcanizing agent consisting of 213-dimercaptopyrazine, 2,3-dimercaptoquinoxaline, or a derivative thereof (Japanese Patent Publication No. 144, No. 144). Publication No. and Special Publication No. 5
8-14469), this vulcanizing composition sometimes caused premature vulcanization during storage or molding.

Regarding the suppression of early vulcanization during molding, it has already been disclosed in the above-mentioned specification that certain thiophthalimides are effective. 4. There is no corresponding technology that has been proposed.

The present inventors have discovered that the presence of N-phenyl-N-trichloromethylthiobenzenesulfonamide suppresses early vulcanization of halogen-containing polymers during molding and storage, and have thus arrived at the present invention. be. Examples of the halogen-containing polymer used in the present invention include chlorinated polyethylene, chlorinated ethylene-propylene copolymer, chlorinated ethylene-propylene-nonconjugated diene terpolymer, chloro, sulfonated polyethylene, polyvinyl chloride, Chlorinated acrylic rubber, chlorinated butyl rubber, brominated butyl rubber, fluororubber, polychloroprene, polyepichlorohydrin, epichlorohydrin-allyl glycidyl ether copolymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether ternary copolymer Examples include merging.

2,3-dimercaptopyrazine, 2,3-dimercaptoquinoxaline, or a derivative thereof used as a vulcanizing agent in the present invention is a compound represented by the following general formula (2). However, in the above general formula (A), R
l and R2 may be the same or different and represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, or Rl
, R2 may be combined to form a benzene ring which may have at least one substituent selected from halogen, nitro group, carboxyl group, lower alkyl group, and lower alkoxyl group.

R3 and R4 may be the same or different, and are hydrogen atoms,
It may represent an alkali metal, 1N-8, or R3 and R4 may be bonded to each other to form a C=O group.

In this case, R5 and R6 may be the same or different,
represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group, an aralkyl group, or R
2 and R6 may be bonded to each other to form a 6-membered hetero ring. Further, R7 represents a group having 1 to 18 carbon atoms selected from an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, and an aralkyl group, or (R97
Represents a Japanese cabbage, n=o or 1, and when n=1, R8 is a group having 1 to 8 carbon atoms selected from an alkylene group and an alkenylene group, and . represents a group having 6 to 12 carbon atoms selected from a cycloalkylene group and an arylene group. Further, the above +R97- may form an ester bond within the same group or with a mercapto group of another 2,3-dimercaptopyrazine or 2,3-dimercaptoquinoxaline or a derivative thereof.

1I Keo (A) Ashi University hsu 1k article komeshikakeme Jpu is,
2,3-dimercaptopyrazine, pyrazine-2,3-dithiocarbonate, 5-methyl-2,3-dimercaptopyrazine, 5-ethylpyrazine-2,3-dithiocarbonate, 5,6-dimethyl-2,3-dimercaptopyrazine) 5 , 6-dimethylpyrazine-2,3-dithiocarbonate, N-methyl-3(2-mercaptopyrazyl)sulnophenamide, N,N-dicyclohexyl-3(5-ethyl-2-mercaptopyrazyl)sulfenamide, 5
-isopropyl-2-mercaptopyrazi-3-thiol benzoate, ,5,6-dimethyl-2-mercaptopyrazi-3-thiol sebacate, 2,3-dimercaptoquinoxaline, quinoxaline-2,3-dithiocarbonate, 6-ethyl-2 , 3-dimercaptoquinoxaline ~ 6-methylquinoxaline-2,3-dithiocarbonate, 6,7-di(n-butyl)-2,3-dimercaptoquinoxaline, N,N-dicyclohexyl-3(2-mercaptoquinoxaline) ) Sulfenamide, N-(n-butyl)-3(6-methyl-2-mercaptoquinoxaline)sulfenamide, 6-isopropyl-2-mercaptoquinoxalyl-3-thiol acetate, 5,8-dimethyl-2-mercaptoquinoxalyl-3 -thiol benzoate, 6-isobutyl-2-mercaptoquinoxalyl-3-thiol sebacate, 6-bromo-2,3-dimercaptoquinoxaline ~ 6-methoxyquinoxaline-2,3-dithiocarbonate, 6-nitro-2,3-di Examples include mercaptoquinoxaline to 6-carboxyquinoxaline-2,3-dithiocarbonate.

The amount of the vulcanizing agent used is 0.1 to 1 part by weight, preferably 0.1 to 1 part by weight per 1 part by weight of the Nowagen-containing polymer. Preferably, the range is 0.2 to 5 parts by weight. N-phenyl-N-trichloromethylthiobenzenesulfonamide used for suppressing early vulcanization in the present invention is a compound represented by the following formula. The amount of the above compound to be used is 0.1 to 5 parts by weight, preferably 0.1 to 5 parts by weight, per 10 parts by weight of the halogen-containing polymer.
A range of 2 to 2 parts by weight is suitable.

In the present invention, along with the imparted early vulcanization suppressing effect,
In order to obtain a more rapid vulcanization accelerating effect during vulcanization, basic silica, sulfur, thiuram sulfides, dithiocarbamates, polyols, amines or their weak acid salts or their adducts, 1,8 -diazabicyclo(5,
4,0) Accelerators such as undecene-7 or its salts, quaternary ammonium salts, quaternary phosphonium salts, glymes, etc. can be added.

Specific examples of such accelerators include tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide, tellurium diethyldithiocarbamate, nickel dibutyldithiocarbamate, pentaerythritol, sorbitol, 2-mercaptobenzothia dicyclohexylamine. dill salt, butyraldehyde-aniline condensate, diphenylguanidine, phenol salt of 1,8-diazabicyclo(5,4,0)undecene-7, tetraphenylammonium chloride, tetrabutylphosphonium bromide, polyethylene glycol monolauryl Ether etc. can be mentioned. During the vulcanization in the present invention, the vulcanization composition may contain various additives commonly used in the technical field, such as vulcanization accelerators, acid acceptors, fillers, reinforcing agents, plasticizers, and processing aids. ,
Anti-aging agents, pigments, flame retardants, etc. can be optionally added.

As a method for blending the composition of the present invention, any means conventionally used in the field of polymer processing can be used, such as mixing rolls, Panbury mixers, and various seconders. The above mixed composition usually contains 100 to 2
A vulcanizate can be obtained by heating the powder at 00C for 0.1 to 30 minutes.

As a method for vulcanization molding, any method such as pressure molding using a mold, injection molding, steam can, heating using an air bath, infrared rays, microwave, etc. can be used. The present invention will be explained below with reference to Examples.

Examples 1-5, Comparative Examples 1-6 Immediately after kneading and after kneading the compositions obtained by kneading each compound shown in Table 1 with an open roll at 60-70C and 35°C after kneading.
Table 2 shows the results of the Mooney scorch test conducted after standing for 12 hours at a humidity of 75%.

Table 3 shows the vulcanized physical properties of each vulcanizate obtained by pressure molding in a three-powder mold at 155° C. immediately after kneading. In addition, for the formulations of Example 11 and Comparative Examples 1 and 2, immediately after kneading and 3
The vulcanization curve after 12C@standing at 5℃ and 75% humidity was measured using a JSR model Cyulastometer at a 3-line oscillation angle and a temperature of 155℃, and the results are shown in Figures 1 and 2. They are shown in Figure 2.

[Brief explanation of the drawing]

FIG. 1 shows the vulcanization curves of Example 1 and Comparative Examples 1 and 2 immediately after kneading.

Claims (1)

[Claims] 1. When vulcanizing a halogen-containing polymer with 2,3-dimercaptopyrazine or 2,3-dimercaptoquinoxaline or a derivative thereof, N-phenyl-
1. A method for inhibiting early vulcanization of a halogen-containing polymer, comprising the presence of N-trichloromethylthiobenzenesulfonamide.