JPH0115527B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a crosslinkable elastomer composition, and more specifically, the present invention relates to a crosslinkable elastomer composition that has heat resistance, low temperature brittleness resistance, and oil resistance, and is mainly composed of a copolymer of ethylene, an acrylic ester or a methacrylic ester, and an unsaturated glycidyl ester. The present invention relates to a crosslinkable elastomer composition that has both properties and properties. In recent years, with remarkable technological advances in various industries such as automobiles, home appliances, and machinery, the characteristics required of rubber materials used in various related parts have become diverse, and various special elastomers are being developed to meet these requirements. As is well known. As such elastomers, for example, crosslinkable elastomer compositions based on copolymers consisting of ethylene, (meth)acrylic acid esters, and unsaturated glycidyl esters are known, but these still have low vulcanization speed and heat resistance. The present inventors conducted research to further improve elastomer compositions mainly composed of such copolymers, and as a result, they arrived at the present invention. That is, the present invention provides (1) (a) 50 to 85 mol% ethylene, (b) 50 to 15 mol%
acrylic ester or methacrylic ester and (c) 0.1 to 5 mol% of unsaturated glycidyl ester based on the total of both components (a) and (b). ) (d) A polyfunctional organic amine or a salt thereof and (e) Sulfur and/or a sulfur donating compound are blended to provide a crosslinkable elastomer composition with improved vulcanization rate and heat aging resistance. It is. The acrylic ester or methacrylic ester that is a constituent component of the copolymer in the present invention is an ester consisting of an alcohol having 1 to 8 carbon atoms, and specifically includes methyl acrylate, methyl methacrylate, ethyl acrylate, Examples include ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and one type of these may be used. Two or more types may be mixed and used. The molar ratio of (a) ethylene and (b) acrylic ester or methacrylic ester is 50 to 85:50.
15, preferably 58-80:42-20. The content of acrylic ester or methacrylic ester in the copolymer composition is 50 to 15 mol%, preferably 42 to 20 mol%.
When the content of acrylic ester and/or methacrylic ester exceeds the upper limit, the brittle point becomes high, making it difficult to use as an elastomer at low temperatures. On the other hand, if it is lower than the lower limit, the crystallinity of the copolymer will become high, making it impossible to obtain sufficient elasticity as an elastomer. Examples of unsaturated glycidyl esters used in the present invention include glycidyl acrylate, glycidyl methacrylate, itaconate diglycidyl ester, butene tricarboxylic acid triglycidyl ester, and p-
Examples include styrene carboxylic acid glycidyl ester, and these may be used alone or in combination of two or more. The amount of unsaturated glycidyl ester to be used is as specified in (a) above.
and (b) in an amount of 0.1 to 5 mol %, preferably 0.2 to 3 mol %, based on the total of both components. If the content of unsaturated glycidyl ester exceeds the upper limit, scorch resistance will be poor, and if it is lower than the lower limit, sufficient crosslinking effect will not be obtained. It is also possible to copolymerize the copolymer of the present invention with other comonomers that are copolymerizable with ethylene. Specific examples include isobutylene, styrene and its derivatives, vinyl acetate, and halogenated olefins such as tetrafluoroethylene and hexafluoropropylene. The copolymer of the present invention is produced by a known method. For example, they can be produced by free radical initiated bulk polymerization, emulsion polymerization or solution polymerization. A typical polymerization method is described in the Japanese Patent Publication Showa
No. 46-45085. For example, it can be produced in the presence of a polymerization initiator that generates free radicals, optionally in the presence of a polymerization regulator, under conditions of a pressure of 500 Kg/cm ³ or higher and a temperature of 40 to 300°C. The copolymer used in the present invention is obtained by copolymerizing the above-mentioned components, and has a melting index at 190°C defined by JIS K6791 of 0.5 to 500 g/10 minutes, preferably 0.5 to 50 g/10 minutes. A copolymer is used. In the present invention, (d) a polyfunctional organic amine or a salt thereof and (e) sulfur and/or a sulfur donating compound are used in combination as a crosslinking agent. Here, polyfunctional organic amine salts or their salts include aliphatic diamines such as polymethylene diamine and polyether diamine, diethylene triamine, substituted polyamines, iminobispropylamine, bis(hexamethylene) triamine, triethylenetetramine, and tetraethylene. pentamine,
Aliphatic polyamines such as pentaethylenehexamine, aminoethylethanolamine, methyliminobispropylamine, carbamates such as ethylenediamine carbamate and hexamethylenediamine carbamate, menthanediamine, N-aminoethylpiperazine, 1,3-diaminocyclohexane, isophoronediamine alicyclic polyamines such as m-xylylene diamine, tetrachloro-p-xylylene diamine, aliphatic amines with aromatic rings such as N,N'-dicinnamylidene-1,6-hexane diamine, m-phenylene diamine, Diaminodiphenyl ether, 4,4-methylene dianiline, diaminodiphenyl sulfone,
benzidine, 4,4'-bis(O-toluidine),
4,4'-thiodianiline, O-phenylenediamine, dianisidine, methylenebis(O-chloroaniline), 2,4-toluenediamine, bis(3,
Aromatic amines such as 4-diaminophenyl) sulfone, diaminoditolylsulfone, 4-chloro-O-phenylenediamine, 4-methoxy-6-methyl-m-phenylenediamine, m-aminobenzylamine, N- Examples include secondary amines such as methylpiperazine, hydroxyethylpiperazine, piperidine, pyrrolidine, morpholine, tertiary amines such as tetramethylguanidine, 2,4,6-tris(dimethylaminomethyl)phenol, and salts thereof. may be used alone or in combination of two or more. In addition to ordinary powdered sulfur, insoluble sulfur, colloidal sulfur, and surface-treated sulfur used in the rubber processing industry are used as sulfur, and sulfur-donating compounds include sulfur chloride, sulfur trichloride, and morpholine disulfide. , alkylphenol disulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram disulfide, dipentamethylenethiuram tetrasulfide, dipentamethylenethiuram hexasulfide These may be used alone or in combination of two or more. The amount of polyfunctional organic amines or salts thereof added is 0.1 to 5 parts by weight, preferably 0.3 to 3 parts by weight, per 100 parts by weight of the copolymer used in the present invention, and sulfur and/or sulfur donating compounds are added. The amount added is 0.05 to 3 parts by weight, preferably 0.1 to 1.5 parts by weight per 100 parts by weight of the copolymer. Here, if the amount used is less than this range, a sufficient crosslinking effect will not be obtained, and if it exceeds this range, the elongation of the produced crosslinked elastomer will decrease and bloom and bleed will easily occur. In the present invention, crosslinking reaction promoters such as diphenylguanidine, diorthotolylguanidine, phenol, cresol, bisphenol, pentachlorophenol, phenolic resin, triphenyl phosphite, tri(dimethylaminomethyl)phenol are used as necessary. , acetic acid, water, benzoic acid, oxalic acid, salicylic acid, acetonitrile, nitrobenzene, etc. Further, if necessary, vulcanization accelerators, reinforcing agents, fillers, softeners, anti-aging agents, processing aids, zinc white, stearic acid, defoaming agents, etc. known in the rubber industry can be added. The elastomer composition of the present invention is heated under pressure or normal pressure at a temperature of 150°C to 230°C for 5 to 60 minutes, preferably at 160°C to 200°C for 5 to 45 minutes, and if necessary, heated at a temperature of 150°C to 230°C for 5 to 45 minutes. Good practical properties are exhibited by heating in air or inert gas for 1 hour to 24 hours at a temperature of 0.degree. C. to 200.degree. EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples. Examples Table 1 shows the properties of (a) ethylene-(b) (meth)acrylic acid ester-(c) unsaturated diglycidyl ester copolymer produced using high-pressure polyethylene production equipment.

[Table] Each copolymer shown in Table 1 was used and kneaded with a mixing roll at the compounding agents and compounding ratio (parts by weight) shown in Table 2 to obtain each elastomer composition. The properties of these elastomer compositions
Measurements were made in accordance with the provisions of JISK6300 and Japan Rubber Association Standard Specification 3102. Further, this elastomer composition was heated at 170° C. for 20 minutes using a pressure press to cause crosslinking. Furthermore, some of it is heated to 150℃4 in the air.
heated for an hour. The properties of these crosslinked elastomer compositions were measured according to JISK6301. These results are shown in Table 3. The oil resistance test and heat aging test were conducted under the following conditions. Oil resistance test Test oil: Test oil specified by JISK6301
No. 2 Soaking conditions: 150°C for 70 hours Heat aging conditions Testing machine: Gear oven aging tester Aging conditions: 150°C for 10 days 175°C for 5 days From these results, the physical properties of the inventive example after crosslinking were better than that of the comparative example. , without deteriorating oil resistance, t ₅ , t△ ₃₀ of Mooney scorch properties, t′ ₁₀ , t′ ₉₀ of oscillating desk rheometer after crosslinking by press heating.
It is clear that the vulcanization rate expressed by M ₂₀₀ has been improved and the heat aging resistance has also been greatly improved.

【table】

【table】

【table】

Claims (1)

[Claims] 1 (a) 50 to 85 mol% ethylene, (b) 50 to 15 mol%
acrylic ester or methacrylic ester and (c) for the total of both components (a) and (b) above.
A copolymer obtained by copolymerizing 0.1 to 5 mol% of unsaturated glycidyl ester with 2 (d) polyfunctional organic amines or salts thereof and (e) sulfur and/or a sulfur-donating compound. A crosslinkable elastomer composition characterized in that: