JPH11349754A - Chlorinated polyethylene rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject composition capable of affording a cured product of high ozone resistance comparable to that of a press-cured product obtained using a conventional mold even when cured with hot water or steam using a mercaptotriazine-based curing agent. SOLUTION: This composition comprises 100 pts.wt. of a chlorinated polyethylene, 0.1-10 pts.wt. of a mercaptotriazine-based curing agent, 0.1-10 pts.wt. of a curing promoter, 0.1-20 pts.wt. of an acid acceptor, and 0.1-5 pts.wt. of quinoline- and/or p-phenylenediamine-based antioxidant; wherein the chlorinated polyethylene is pref. substantially noncrystalline one with a chlorine content of 20-50 wt.% and optionally contains 0-20 wt.% of a nitrile rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a chlorinated polyethylene rubber composition capable of obtaining a vulcanized chlorinated polyethylene rubber having excellent ozone resistance even when vulcanized with hot water or steam.

[0002]

2. Description of the Related Art Since chlorinated polyethylene has no unsaturated bond in the main chain, chlorinated polyethylene rubber compositions cannot be vulcanized by ordinary sulfur, and generally, organic peroxides, thioureas, diamines, Vulcanizing agents such as mercaptotriazine compounds are used. And the obtained vulcanizate has heat aging resistance, oil resistance, weather resistance, color stability, flame resistance,
It has excellent adhesive properties and printing properties, and is used in various industrial fields.

[0003] In order to vulcanize a chlorinated polyethylene rubber composition using a mercaptotriazine vulcanizing agent, a vulcanization method similar to that of sulfur vulcanization of ordinary rubber, for example, a hot water or steam vulcanization can, Methods using a lead vulcanizing apparatus, a hot blast stove, a mold and the like can be applied, and these methods are very suitable vulcanizing methods. However, among the vulcanizates obtained by these methods, the vulcanizates obtained by vulcanizing the chlorinated polyethylene rubber composition with hot water or steam are press vulcanizates obtained using a mold. However, it has a drawback that it is inferior in physical properties such as tensile strength and ozone resistance.

[0004] With respect to the tensile strength, measures for improving the tensile strength have been proposed (see Japanese Patent Publication No. 64-3897), but no measures for improving the ozone resistance have been taken so far.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a press vulcanization using a mold even when vulcanizing with hot water or steam using a mercaptotriazine vulcanizing agent. An object of the present invention is to provide a chlorinated polyethylene rubber composition capable of obtaining a vulcanizate exhibiting excellent ozone resistance similar to that of a vulcanizate.

[0006]

Means for Solving the Problems The present inventors have conducted various studies to solve the above-mentioned problems, and as a result, it has been found that the ozone resistance of a vulcanized product can be improved by adding a certain type of antioxidant. And completed the present invention.

That is, the chlorinated polyethylene rubber composition of the present invention comprises 100 parts by weight of chlorinated polyethylene, 0.1 to 10 parts by weight of a mercaptotriazine vulcanizing agent, 0.1 to 10 parts by weight of a vulcanization accelerator, It is characterized by containing 0.1 to 20 parts by weight of an acid agent, 0.1 to 5 parts by weight of a quinoline antioxidant and / or a p-phenylenediamine antioxidant.

The chlorinated polyethylene is preferably a substantially amorphous one having a chlorine content of 20 to 50% by weight.

[0009] Chlorinated polyethylene is obtained by converting nitrile rubber from 0 to
20% by weight.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail.

The chlorinated polyethylene used in the present invention is obtained by chlorinating polyethylene powder or particles in an aqueous suspension or in an organic solvent. Those obtained by chlorination at a higher temperature are preferred. The raw material polyethylene is an ethylene homopolymer or a copolymer with a comonomer copolymerizable with ethylene. Examples of the comonomer include α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-pentene-1; acetates such as vinyl acetate and ethyl acetate; ) Acrylic acid; and (meth) acrylates such as methyl (meth) acrylate and ethyl (meth) acrylate. The weight average molecular weight of polyethylene is preferably 40,000 to 700,000, more preferably 50,000 to 300,000.

The polyethylene as a raw material may be a high-density polyethylene or a blend of an amorphous chlorinated polyethylene and a low-density polyethylene as a raw material.

[0013] The chlorine content of the chlorinated polyethylene used in the present invention is preferably 20 to 50% by weight, more preferably 25 to 45%. If the chlorine content is too high or too low, the resulting composition may have too high a hardness. Amorphous or substantially amorphous chlorinated polyethylene is preferred.

The nitrile rubber which can be blended with the chlorinated polyethylene is a copolymer of acrylonitrile and butadiene, and any copolymer composition ratio such as so-called high nitrile, medium and high nitrile, medium nitrile and low nitrile can be used. The proportion of the nitrile rubber in the blend of the chlorinated polyethylene and the nitrile rubber is 0 to 20% by weight, preferably 5 to 10% by weight. The ratio of nitrile rubber is 2
If it exceeds 0% by weight, the heat resistance tends to decrease.

The vulcanizing agent used in the present invention comprises a mercaptotriazine compound represented by the following general formula (I).

[0016]

Embedded image (Wherein, R is a group selected from the group consisting of mercapto, alkoxy, alkylamino, dialkylamino, cycloalkylamino, dicycloalkylamino, and arylamino groups)

Specific examples include 2,4,6-trimercapto-1,3,5-triazine, 1-methoxy-3,5
-Dimercaptotriazine, 1-hexylamino-3,
5-dimercaptotriazine, 1-diethylamino-
3,5-dimercaptotriazine, 1-cyclohexylamino-3,5-dimercaptotriazine, 1-dibutylamino-3,5-dimercaptotriazine, 1-phenylamino-3,5-dimercaptotriazine and the like. . These vulcanizing agents may be used alone or in combination of two or more.

The ratio of the vulcanizing agent is chlorinated polyethylene 100
The amount is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight with respect to parts by weight. If the proportion of the vulcanizing agent is less than 0.1 part by weight, the vulcanization becomes insufficient, while if it exceeds 10 parts by weight, the rubber elasticity is lost and the product becomes too hard.

The vulcanization accelerator used in the present invention includes:
Generally, those having strong accelerating power are preferable, and examples thereof include basic accelerators, sulfenamide accelerators, and thiuram accelerators.

Examples of the basic accelerator include basic amine compounds, organic acid salts or adducts of basic amines, diarylguanidines, polycondensates of aniline and aldehydes, and the like.

Specifically, as the basic amine compound,
n-hexylamine, octylamine, dibutylamine, tributylamine, trioctylamine, di (2-
Ethylhexyl) amine, dicyclohexylamine, hexamethyleneamine and the like are exemplified. Organic acids that form salts with amines include carboxylic acids, carbamic acids,
Examples include mercaptobenzothiazole, dithiophosphoric acid and the like. Examples of the substance forming an adduct with an amine include alcohols and oximes. Specific examples of organic acid salts or adducts of amines include n-butylamine.
Acetate, dibutylamine oleate, hexamethylenediamine carbamate, dicyclohexylamine salt of 2-mercaptobenzothiazole and the like can be mentioned.

Examples of the diarylguanidine include diphenylguanidine, ditolylguanidine and the like.

Examples of condensed products of aniline and aldehyde include condensates of aniline and butyraldehyde.

The sulfenamide-based accelerator comprises a primary or secondary amine 2-benzothiazylsulfenamide as shown by the following general formula (II).

[0025]

Embedded image (Wherein R ¹ and R ² are the same or different and are a hydrogen atom, an alkyl group, a cycloalkyl group, or an aralkyl group, provided that R ¹ and R ² are not both hydrogen atoms. R ¹ and R ² May combine with each other to form a ring with or without a hetero atom.)

The primary or secondary amine forming sulfenamide includes cyclohexylamine, butylamines, diethylamine, dipropylamines, dioctylamines, dilaurylamines, dicyclohexylamine, piperidine, pipecoline, morpholine, piperazine. Etc. are exemplified.

Specific examples of the sulfenamide-based accelerator include N-ethyl-2-benzothiazylsulfenamide, Nt-butyl-2-benzothiazylsulfenamide, N, N-di-isopropyl -2-benzothiazylsulfenamide, N, N-di-n-butyl-2-benzothiazylsulfenamide, N, N-di-cyclohexyl-2-benzothiazylsulfenamide, N-oxy- And diethylene-2-benzothiazylsulfenamide.

The thiuram-based accelerator has the following general formula (III)
And a thiuram sulfide compound represented by

[0029]

Embedded image (Wherein, R ¹ and R ² and / or R ³ and R ⁴ are the same or different and are, for example, an alkyl group, an aryl group, a cycloalkyl group, an aralkyl group. R ¹ and R ² , and / or R ³ And R ⁴ may be bonded to each other to form a ring with or without a hetero atom.)

Specific examples of the thiuram-based accelerator include tetramethylthiuram disulfide, tetramethylthiuram monosulfide, tetraethylthiuram disulfide,
Tetrabutylthiuram disulfide, dipentamethylenethiuram tetrasulfide and the like can be mentioned.

These vulcanization accelerators may be used alone or in combination of two or more.

The ratio of the vulcanization accelerator is chlorinated polyethylene 1
The amount is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 00 parts by weight. When the proportion of the vulcanization accelerator is
If the amount is less than 0.1 part by weight, the effect of promoting vulcanization is poor, while if it exceeds 10 parts by weight, no further effect can be expected.

The acid acceptor used in the present invention is a compound that captures hydrogen chloride released from chlorinated polyethylene during vulcanization, and includes metal oxides such as magnesium oxide and calcium oxide, magnesium hydroxide, calcium hydroxide and the like. Metal hydroxide, hydrotalcite such as synthetic hydrotalcite, lead white, lead red, litharge and the like.

These acid acceptors may be used alone,
You may use it in combination of 2 or more types.

The ratio of the acid acceptor is chlorinated polyethylene 100
It is 0.1 to 20 parts by weight, preferably 5 to 20 parts by weight with respect to parts by weight. If the proportion of the acid acceptor is less than 0.1 part by weight, the acid accepting effect is poor, while if it exceeds 20 parts by weight, no further effect can be expected.

The antioxidants used in the present invention are a quinoline antioxidant and a p-phenylenediamine antioxidant.

Examples of the quinoline anti-aging agent include poly (2,2,4-trimethyl-1,2-dihydroquinoline) and 6-ethoxy-2,2,4-trimethyl-1,2.
-Dihydroquinoline is exemplified.

Examples of the p-phenylenediamine-based antioxidants include N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine and N, N'-di-2-.
Naphthyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N, N '
-Diphenyl-p-phenylenediamine, N-cyclohexyl-N'-phenyl-p-phenylenediamine, N
-Phenyl-N '-(3-methacryloyloxy-2-
(Hydroxypropyl) -p-phenylenediamine, N,
N'-bis (1-methylheptyl) -p-phenylenediamine, N, N'-bis (1,4-dimethylpentyl)
-P-phenylenediamine, N, N'-bis (1-ethyl-3-methylpentyl) -p-phenylenediamine.

These antioxidants may be used alone or in combination of two or more.

The ratio of the antioxidant is chlorinated polyethylene 1
The amount is 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight based on 00 parts by weight.

When the proportion of the anti-aging agent is less than 0.1 part by weight, the anti-aging effect is poor. On the other hand, when the proportion exceeds 5 parts by weight, the product tends to suffer from blooming.

The chlorinated polyethylene rubber composition according to the present invention can be used in the form of commonly used reinforcing agents, fillers, plasticizers, processing aids, stabilizers, ultraviolet absorbers, pigments, flame retardants, foaming agents, and vulcanizing agents. Agents and the like can be included as needed. To obtain the chlorinated polyethylene rubber composition according to the present invention,
The usual method used in the rubber processing field can be applied. For example, the above components are kneaded using a mixing roll, a Banbury mixer, a twin-screw kneading extruder, various kneaders and the like, and the obtained kneaded product is formed into a required shape such as a sheet by an open roll or the like.

By vulcanizing the chlorinated polyethylene rubber composition having the above constitution with hot water or steam using a vulcanizer, a chlorinated polyethylene rubber vulcanizate having excellent ozone resistance can be obtained. The vulcanization conditions are 100 to 200 ° C. for several minutes to 12 hours depending on the vulcanizing agent and vulcanization accelerator used.
It is appropriately selected within a range of 0 minutes.

[0044]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments for carrying out the present invention will be described below with reference to examples. However, the present invention is not limited to the following embodiments unless departing from the gist thereof. Example 1 As shown in Table 1, chlorinated polyethylene 1
1.25 parts by weight of a vulcanizing agent and 2.5 parts by weight of a vulcanizing accelerator
Table 1 shows parts by weight, 10 parts by weight of an acid acceptor, 1 part by weight of an antioxidant, and filler, plasticizer, lubricant, and vulcanizing agent for nitrile rubber.
And the resulting blend was kneaded in a kneader for 10 minutes. The obtained kneaded material was formed into a sheet shape using an open roll to obtain a rubber composition having a thickness of about 2 mm.

The sheet-like rubber composition thus obtained was subjected to steam vulcanization at 150 ° C. for 15 minutes using a vulcanizer to obtain a rubber vulcanizate.

[Examples 2 to 6 and Comparative Examples 1 to 6] Table 1
A sheet-like rubber composition was obtained by further performing the same operation as in Example 1 except that the compounding materials shown in Table 2 were used in the proportions shown in Table 2, and further a rubber vulcanizate was obtained. .

[0047]

[Table 1]

[0048]

[Table 2]

* 1 Daisorak MR104 (manufactured by Daiso) chlorine content 40% by weight * 2 N240S (manufactured by Nippon Synthetic Rubber) * 3 Adekasizer RS107 (manufactured by Asahi Denka Kogyo) * 4 sorbitan monostearate * 5 magnesium hydroxide * 6 Nocrack 224 (poly (2,2,4-trimethyl-1,2, -dihydroquinoline)) (Ouchi Shinko Chemical Co., Ltd.) * 7 Nocrack 6C (N- (1,3-dimethylbutyl)
-N'-phenyl-p-phenylenediamine (Ouchi Shinko Chemical Co., Ltd.) * 8 Nocrack White (N, N'-di-2-naphthyl-p-phenylenediamine) (Ouchi Shinko Chemical Co., Ltd.) * 9 M-181 (2-mercaptobenzothiazole salt of dicyclohexylamine) (manufactured by Daiso Corporation) * 10 OF-100 (2,4,6-trimercapto-
1,3,5-triazine) (Daiso) * 11 N- (cyclohexylthio) phthalimide * 12 Nocrack NBC (nickel dibutyldithiocarbamate) (Ouchi Shinko Chemical Co., Ltd.) * 13 Nocrack NS-6 (2 2'-methylenebis (4
-Methyl-6-tert-butylphenol)) (Ouchi Shinko Chemical Co., Ltd.)

[Performance Test] A dumbbell-shaped No. 1 test piece specified in JIS K6251 (medium small width part length 40 mm, width 1) was obtained from the rubber vulcanizates obtained in Examples and Comparative Examples.
0 mm, thickness 2.0 ± 0.2 mm).
JIS K6259 "Test method for ozone deterioration of vulcanized rubber"
, A dynamic ozone degradation test was conducted under the conditions of an ozone concentration of 50 pphm, a temperature of 40 ° C, and an elongation of 30%, to examine ozone resistance. The evaluation criteria for ozone resistance are as follows.

Number of cracks A: Small number of cracks B: Many cracks C: Infinite number of cracks Size and depth of cracks 1: Those that cannot be seen with the naked eye but can be confirmed with a magnifying glass of 10 times 2: Those that can be confirmed with the naked eye 3: Cracks deep and relatively large (crack length less than 1 mm) 4: Cracks deep and large (crack length 1 mm or more and 3 m)
m: 5: Cracks or cuts with a length of 3 mm or more are likely to occur.

The evaluation results of the ozone resistance are represented by a combination of the number of cracks and the size and depth of the cracks.

The test results are shown in Tables 3 and 4.

[0054]

[Table 3]

[0055]

[Table 4]

As is clear from the evaluation results, the rubber vulcanizates of the examples obtained from the chlorinated polyethylene rubber compositions containing the specific antioxidant showed good ozone resistance.

[0057]

The chlorinated polyethylene rubber composition according to the present invention can provide a chlorinated polyethylene rubber vulcanizate having excellent resistance to ozone deterioration even when vulcanized with hot water or steam.

Claims (4)

[Claims] 1. 100 parts by weight of chlorinated polyethylene, 0.1 to 10 parts by weight of a mercaptotriazine vulcanizing agent, 0.1 to 10 parts by weight of a vulcanization accelerator, 0.1 to 20 parts by weight of an acid acceptor, quinoline A chlorinated polyethylene rubber composition comprising 0.1 to 5 parts by weight of an antioxidant and / or a p-phenylenediamine antioxidant. 2. A chlorinated polyethylene having a chlorine content of 20.
The chlorinated polyethylene rubber composition according to claim 1, wherein the composition is substantially amorphous by 50 to 50% by weight. 3. The chlorinated polyethylene has a nitrile rubber of 0%.
The chlorinated polyethylene rubber composition according to claim 1, wherein the composition contains -20% by weight. 4. A chlorinated polyethylene rubber vulcanizate obtained by vulcanizing the chlorinated polyethylene rubber composition according to claim 1 with hot water or steam.