JP3318983B2 - Ethylene-propylene copolymer rubber composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a crosslinked product which is crosslinked in hot air, has no tackiness on the surface of the crosslinked product, does not cause abnormal foaming inside, and has excellent heat resistance and compression set. The present invention relates to an obtainable ethylene-propylene copolymer rubber composition.

[0002]

2. Description of the Related Art Ethylene-propylene copolymer rubbers are:
It does not have an unsaturated group in the main chain, has better heat resistance than general-purpose diene rubber, and is widely used in extrusion products such as water hoses for automobiles, weather strips, and electric wires. On the other hand, ethylene-propylene-diene copolymer rubber (EPDM), which is used in sulfur crosslinking, is required to have a high heat resistance. Due to the necessity of countermeasures, expectations for organic peroxide crosslinking are increasing. Crosslinking of rubber parts made by extrusion molding,
Generally, a method of cross-linking in a batch system in the presence of pressurized steam or a method of continuous cross-linking in hot air is employed. In the case of crosslinking using sulfur as a crosslinking agent, a crosslinked product having no stickiness on the surface can be obtained by the above-described crosslinking method. However, in the case of crosslinking using an organic peroxide, if air (oxygen) comes into contact with rubber, the crosslinking is insufficient. , And cause softening deterioration, the cross-linked product surface sticks,
A satisfactory rubber product could not be obtained. As a method of improving the adhesiveness of the cross-linked surface during continuous cross-linking of EPDM in hot air, a method of blending a silicone rubber and a bismaleimide compound (Japanese Patent Publication No. 58-13093), using EPDM having a very high ethylene content (Japanese Patent Laid-Open No. 64-75552) and the like have been proposed. However, in the method of blending the bismaleimide compound with EPDM, the melting point of the bismaleimide compound is high, dispersing failure is likely to occur during kneading, and great care must be taken to obtain a homogeneous product. Further, the use of resin-like EPDM having a high ethylene content may impair the cold resistance of rubber products. The present inventors have filed Japanese Patent Application No.
-81203 proposed that a high-diene EPDM can be used to obtain a rubber product having low surface tackiness by hot air crosslinking. However, it was necessary to further improve the compression set of thin products.

[0003]

SUMMARY OF THE INVENTION The present invention improves the heat resistance and compression set characteristics (particularly thin rubber products) of extruded products using EPDM, and crosslinks in hot air to produce rubber products. An object of the present invention is to provide a rubber composition having a satisfactory appearance and performance.

The present invention relates to (A) 0.01 to 10 parts by weight of an organic peroxide, and (C) a plurality of acryloys per 100 parts by weight of an ethylene-propylene copolymer rubber.
Acrylate compound having a thiol group (in the present specification,
In this regard, the term "polyfunctional acrylate compound"
U. ) 0.01 to 10 parts by weight of (D) an ethylene containing hindered amine compounds 0.01 to 10 parts by weight -
It is intended to provide a propylene-based copolymer rubber composition.

[0005] The ethylene-propylene copolymer rubber (A) used in the present invention has a propylene content of 25 to 45% by weight, preferably 25 to 35% by weight, and dicyclopentadiene as a third component in an amount of 8 to 8%. 26% by weight, preferably 15 to 25% by weight. here,
If the propylene content is less than 25% by weight, the obtained rubber becomes resin-like and impairs cold resistance. On the other hand, if it exceeds 45% by weight, the surface of the crosslinked product becomes tacky and crosslinking is insufficient. If the content of dicyclopentadiene is less than 8% by weight, the surface of the crosslinked product becomes tacky, while if it exceeds 26% by weight, the heat resistance deteriorates. The ethylene-propylene copolymer rubber (A) used in the present invention preferably has a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 10 to 150.

The ethylene-propylene copolymer rubber (A) can also copolymerize an α-olefin other than propylene. Examples of the α-olefin include butene-1, pentene-1, hexene-1, heptene-
1, octene-1, nonene-1, decene-1 and the like. In addition, various polyenes can be copolymerized. Examples of the polyene include chains such as 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, and 7-methyl-1,6-octadiene. Non-conjugated dienes;
Vinylcyclohexene, cyclohexadiene, methyltetrahydroindene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene,
Cyclic non-conjugated dienes such as 6-chloromethyl-5-isopropenyl-2-norbornene; 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-
Trienes such as 2,2-norbornadiene, 1,3,7-octatriene and 1,4,9-decatriene can be exemplified. Among these, preferred polyenes are cyclic non-conjugated dienes and 1,4-hexadiene,
Especially, 5-ethylidene-2-norbornene.

Next, as the organic peroxide (B) used in the present invention, di-t-butyl peroxide, di-t
-Amyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 1,4- (or 1,
3-) di-t-butylperoxyisopropylbenzene, 2,2-di-t-butylperoxybutane, 2,2
-Di-t-butylperoxyoctane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane,
2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, n-butyl-4,4-di-t-butylvalerate, 1,1-di-t-butylperoxycyclohexane 1,1-bis (t-butylperoxy) cyclododecane, 1,1-di-t-butylperoxy-
3,3,5-trimethylcyclohexane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl)
Dialkyl peroxides such as propane; t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxypivalate, t-butyl peroxymaleic acid, t-butyl peroxy neodecanoate; t-butyl peroxybenzoate, di-
Peroxyesters such as t-butyl peroxyphthalate, t-butyl peroxy dilaurate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butyl peroxyisopropyl carbonate;
Examples include ketone peroxides such as dicyclohexanone peroxide, and mixtures thereof.
Above all, the temperature giving a half-life of 1 minute is 130-200 ° C.
The use of an organic peroxide in the range of
5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, n-butyl-4,4-di- t
-Butyl valerate, t-butyl cumyl peroxide, dicumyl peroxide, 2,2-bis (4,4-
Di-t-butylperoxycyclohexyl) propane,
Organic peroxides such as 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane can be preferably used. (B) The compounding amount of the organic peroxide is 0.01 to 10 parts by weight, preferably 1 to 7 parts by weight based on 100 parts by weight of the component (A). There is a problem in that it does not proceed sufficiently and the mechanical strength and the compression set are inferior. On the other hand, when it exceeds 10 parts by weight, there is a problem that the elongation of the crosslinked product becomes small.

The rubber composition of the present invention may be blended with an organic polymer other than the component (A) having a double bond and having an iodine value of 10 or more, preferably 20 or more and a glass transition temperature of 25 ° C. or less. By blending this organic polymer, the surface tackiness at the time of hot air crosslinking can be further improved. Specific examples of the organic polymer include butadiene rubber, styrene-butadiene rubber, chloroprene rubber, acryloniloryl-butadiene rubber, acrylic rubber, EPDM other than the component (A), and preferably 1,2-polybutadiene, medium vinyl -High vinyl-styrene-butadiene rubber and the like.
The amount of the organic polymer is 50 parts by weight or less, preferably 25 parts by weight or less, based on 100 parts by weight of the component (A). Further, in order to improve the processability of the rubber composition of the present invention, a resin crosslinkable with butyl halide or an organic peroxide may be blended. Specific examples of the resin include polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, chlorinated polyethylene, and chlorosulfonated polyethylene. The amount of the resin is 50 parts by weight or less, preferably 25 parts by weight or less, based on 100 parts by weight of the component (A).

The polyfunctional acrylate compound as the component (C) is preferably a liquid compound. Specifically, ethylene glycol diacrylate, trimethylolpropane triacrylate, triethylene glycol diacrylate, polyoxyethylene diacrylate, pentane Compounds such as erythritol triacrylate are exemplified. If the amount of component (C) is less than 0.01 part by weight per 100 parts by weight of component (A), the effect of improving compression set is not sufficient, while if it exceeds 10 parts by weight, the crosslinking density is high. Overgrown, reducing product growth. Also,
The rubber composition of the present invention may contain a crosslinkable polyfunctional monomer in addition to the polyfunctional compound as the component (C).
Specific examples of the polyfunctional monomer include allyl compounds such as triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl itaconate, and tetraallyloxyethane; ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate,
Methacrylic acid ester compounds such as triethylene glycol dimethacrylate, polyoxyethylene dimethacrylate, and pentaerythritol trimethacrylate; and divinylbenzene and divinyltoluene. Among these, triallyl isocyanurate, triallyl cyanurate and the like are preferable. The compounding amount of the polyfunctional monomer is 10 parts by weight or less, preferably 5 parts by weight or less based on 100 parts by weight of the component (A).

Specific examples of the hindered amine compound (D) include 4-benzoyloxy-2,
2,6,6-tetramethylpiperidine, bis (2,2,
6,6-tetramethyl-4-piperidyl) sebacate,
4-methacryloxy-2,2,6,6-tetramethylpiperidine, N-methyl-4-methacryloxy-2,2,
6,6-tetramethylpiperidine, bis (1,2,2,
6,6-pentamethyl-4-piperidyl) sebacate,
1- [2- {3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy} ethyl] -4-
{3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy} -2,2,6,6-tetramethylpiperidine, dimethyl-1- (2-hydroxyethyl) -4-succinate Polycondensate of hydroxy-2,2,6,6-tetramethylpiperidine, poly [[6- (1,
(1,3,3-tetramethylbutyl) imino-1,3,5
-Triazine-2,4-diyl] [(2,2,6,6-
Tetramethyl-4-piperidyl) imino] hexamethylene [[2,2,6,6-tetramethyl-4-piperidyl) imino]], 2- (3,5-di-t-butyl-4-)
Bis (1,2,2,6,6-pentamethyl-4-piperidyl) -2-hydroxybenzyl) -2-n-butylmalonate, tetraxy (2,2,6,6-tetramethyl-4)
-Piperidyl) 1,2,3,4-butanetetracarboxylate, 1,2,3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol and tridecyl alcohol Condensate, 1,2,3,4
-Condensation product of butanetetracarboxylic acid, 2,2,6,6-tetramethyl-4-piperidinol and tridecyl alcohol, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6 6-pentamethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-3,9-
Condensate with (2,4,8,10-tetraoxaspiro [5,5] undecane) diethanol, 1,2,3,4-
Butanetetracarboxylic acid, 2,2,6,6-tetramethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-3,9- (2,4,8,10-tetraoxaspiro [ 5,5] undecane) diethanol. Among these, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 1,2,3,4-butane Condensation product of tetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol and tridecyl alcohol, 1,2,3,4
-Condensation product of butanetetracarboxylic acid, 2,2,6,6-tetramethyl-4-piperidinol and tridecyl alcohol, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6 6-pentamethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-3,9-
Condensate with (2,4,8,10-tetraoxaspiro [5,5] undecane) diethanol, 1,2,3,4-
Butanetetracarboxylic acid, 2,2,6,6-tetramethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-3,9- (2,4,8,10-tetraoxaspiro [ A condensate with 5,5] undecane) diethanol is preferably used. (D) The amount of the component is
It is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the component (A). When the amount of the component (D) is less than 0.01 part by weight, the effect of improving the compression set is small. On the other hand, when the amount exceeds 10 parts by weight, the crosslinking is undesirably inhibited. Further, in the rubber composition of the present invention,
An antioxidant may be added. Examples of the antioxidant include styrenated phenol, 2,6-di-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, and 2,6-di-t-butyl-p-ethylphenol. , 2,4,6-tri-t-butylphenol, butylhydroxyanisole, 1-hydroxy-3-methyl-4-isopropylbenzene, mono-t-butyl-p-
Cresol, mono-t-butyl-m-cresol, 2,
4-dimethyl-6-t-butylphenol, butylated bisphenol A, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'-methylene-bis- (4-ethyl- 6-t-butylphenol), 2,2'-methylene-bis- (4-methyl-6-
t-nonylphenol), 2,2'-isobutylidene-
Bis- (4,6-dimethylphenol), 4,4'-butylidene-bis- (3-methyl-6-t-butylphenol), 4,4'-methylene-bis- (2,6-di-t
-Butylphenol), 2,2′-thio-bis- (4-
Methyl-6-t-butylphenol), 4,4′-thio-bis- (3-methyl-6-t-butylphenol),
4,4'-thio-bis- (2-methyl-6-t-butylphenol), 4,4'-thio-bis- (6-t-butyl-3-methylphenol), bis (3-methyl-4 −
(Hydroxy-5-t-butylbenzyl) sulfide;
2,2-thio [diethyl-bis 3- (3,5-di-t-
Butyl-4-hydroxyphenol) propionate], bis [3,3-bis (4'-hydroxy-3'-
t-butylphenol) butyric acid] glycol ester, bis [2- (2-hydroxy-5-methyl-3-t-butylbenzyl) -4-methyl-6-t-butylphenyl] terephthalate, 1,3,5 -Tris (3 ', 5'-di-tert-butyl-4'-hydroxybenzyl) isocyanurate, N, N'-hexamethylene-
Bis (3,5-di-t-butyl-4-hydroxy-hydrocinamide), n-octadecyl-3- (4'-hydroxy-3 ', 5'-di-t-butylphenol) propionate, tetrakis [methylene- ( 3,5-di-t-
Butyl-4-hydroxyphenyl) propionate] methane, 1,1′-bis (4-hydroxyphenyl) cyclohexane, mono (α-methylbenzyl) phenol,
Di (α-methylbenzyl) phenol, tri (α-methylbenzyl) phenol, bis (2′-hydroxy-
3'-t-butyl-5'-methylbenzyl) 4-methyl-phenol, 2,5-di-t-amylhydroquinone, 2,6-di-t-butyl-α-dimethylamino-p
Phenolic antioxidants such as -cresol, 2,5-di-t-butylhydroquinone, diethyl ester of 3,5-di-t-butyl-4-hydroxybenzylphosphoric acid, catechol and hydroquinone; 2-mercaptobenzimidazole Zinc salt of 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, 2
-Zinc salt of mercaptomethylbenzimidazole, 2-
Benzimidazole antioxidants such as zinc salt of mercaptomethylimidazole; aliphatic thioether antioxidants such as dimistyl thiodipropionate, dilauryl thiodipropionate, distearyl thiodipropionate, and ditridecyl thiodipropionate Agents: metal salts of dialkyldithiocarbamic acids such as zinc or nickel salts of dibutyldithiocarbamic acid, zinc salts of diethyldithiocarbamic acid, zinc salts of ethyl-phenyl-dithiocarbamic acid, zinc salts of dimethyldithiocarbamic acid, and zinc salts of diatyldithiocarbamic acid Antioxidants;
2,2,4-trimethyl-1,2-dihydroquinoline,
Or a polymer thereof, a quinoline-based antioxidant such as 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline or the like; Examples can be given. Among these antioxidants, 2, 2,
4-trimethyl-1,2-dihydroquinoline polymer, 2
-Mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole, nickel salt of dibutyldithiocarbamate, mono (α-methylbenzyl) phenol,
Di (α-methylbenzyl) phenol, tri (α-methylbenzyl) phenol, 2,6-di-t-butyl-4
-Methylphenol, N- (3'-hydroxybutylidene) -1-naphthylamine and at least 2
A combination of species can be preferably exemplified. The compounding amount of the antioxidant is 10 parts by weight or less, preferably 5 parts by weight or less based on 100 parts by weight of the component (A).

The composition of the present invention may further contain a processing aid for improving the processability of the rubber composition. Examples of the processing aid include a softener, a plasticizer, and a tackifier. Specific examples of such processing aids include process oils, lubricating oils, paraffins, liquid paraffins, synthetic polymer softeners such as liquid polybutene, and ester plasticizers such as phthalic acid, adipic acid, and sebacic acid. Can be mentioned. Among such processing aids, paraffin-based process oils, liquid paraffins, and the like are preferable. The amount of the processing aid is 100% for the component (A).
It is about 200 parts by weight or less, preferably about 150 parts by weight or less based on parts by weight.

Further, various fillers can be blended in the composition of the present invention. Examples of the filler include carbon black, wet and dry silica, clay, talc, various silicates such as wollastonite, carbonates such as calcium carbonate and magnesium carbonate, zinc oxide, aluminum oxide, titanium oxide and the like. Illustrative examples include metal oxides and surface-treated fillers with a coupling agent thereof, among which carbon black, silica and silicate are preferred. The amount of the filler is 200 parts by weight or less, preferably 1 part by weight, per 100 parts by weight of the component (A).
It is about 80 parts by weight or less.

The composition of the present invention may further contain a foaming agent and a foaming aid for the purpose of forming a foam. Examples of such blowing agents include inorganic blowing agents such as sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, ammonium nitrite;
Nitroso compounds such as N, N'-dimethyl-N, N'-dinitrosoterephthalamide, N, N'-dinitrosopentamethylenetetramine; azodicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile, azodiaminobenzene And azo compounds such as barium azodicarboxylate; benzenesulfonylhydrazide, toluenesulfonylhydrazide, p, p'-oxybis (sulfonylhydrazide), diphenylsulfone-
Sulfonyl hydrazide compounds such as 3,3'-disulfonyl hydrazide; and azide compounds such as calcium azide, 4,4'-diphenyldisulfonyl azide and p-toluenesulfonyl azide. Of these, nitroso compounds, sulfonyl hydrazide compounds, and azide compounds are preferably used. The above foaming agents may be used alone or in combination of two or more. In addition to the rubber composition of the present invention, other compounding agents used in normal rubber compounding, such as a dehydrating agent such as calcium oxide, a coloring agent, a pigment, an ultraviolet absorber, and a flame retardant can be used.

The method for preparing the rubber composition of the present invention is not particularly limited. For example, (A) an ethylene-propylene-based copolymer rubber and (B) an organic peroxide (further, if necessary, Can be added and kneaded at the same time, or the component (B) can be added after the component (A) and other additives are mixed in advance. Mixing can be performed by kneading with a closed kneader such as a roll mill, a Banbury mixer, an intermix, a pressure kneader, or various extruders.

[0015]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto. In the examples, parts and percentages are by weight unless otherwise specified. In addition, the method for evaluating physical properties in the examples is as follows.
The following measurement method was used.

Comparative Examples 1 to 6, Examples 1 to 5 Compounded rubber (rubber composition) according to the compounding recipe shown in Table 1.
After preparing the above, a crosslinked product was obtained. The production method was as follows. The component [I] in Table 1 was kneaded with a 1.7-liter BR type Banbury mixer at a rotor rotation speed of 60 rpm at a temperature of 50 ° C. for 4 minutes, and then with a 10-inch roll maintained at 50 ° C. The component [II] in Table 1 was kneaded for 5 minutes. The roll rotation speed of the front and rear rolls was 23/20 rpm, respectively. The obtained compounded rubber was formed into a molded product using a 50 φmm extruder (die temperature 70 ° C), and kept at 200 ° C for 10 minutes with a gear heat aging tester to obtain a crosslinked product. The die attached to the extruder is shown in FIG. Various physical properties were evaluated using this crosslinked product. Table 2 shows the results. In addition, the evaluation method of various physical properties is as follows.

Mooney scorch test The compounded rubber obtained according to the compounding formula shown in Table 1 was subjected to JI
Mooney scorch time of unvulcanized rubber was measured according to SK6300. The rotor is L-shaped and the test temperature is 12
It was measured at 5 ° C. Tensile test, hardness test, heat aging test A 2 mm-thick cross-linked sheet formed using the die shown in Fig. 1 [I] is punched out with a No. 3 dumbbell according to JIS K6301, and pulled at a pulling speed of 500 mm / min at 25 ° C. The strength and elongation were measured. Furthermore, JIS K6301
The hardness (JIS A) of the crosslinked sheet was measured according to the following.
In addition, the heat aging test was conducted according to JIS K6301 by using the No. 3 dumbbell at 120 ° C. and 7 ° C. with a gear aging tester.
After heat aging for 0 hours, the tensile strength, elongation, and hardness were measured, and the rate of change was determined. Adhesiveness of cross-linked product surface An uncross-linked sheet having a thickness of 2 mm formed using a die shown in FIG.
After cross-linking with hot air, the cross-linked sheet was taken out, and immediately afterwards, the surface of the cross-linked sheet was scratched with a HB pencil to observe the state of chipping. This was used as an index of surface tackiness. ◎: No scratches at all ○: Slight scratches Δ: Slightly scratched X: Slightly peeling Compression set Strain of cross-linked product formed using a die shown in FIGS. 1 [II] and [III] According to JIS K6301, a compression strain of [II] of 50% and [III] of 25% was applied in the direction of a → b, and the compression set at 70 ° C. for 96 hours was measured.

[0018]

[Table 1]

Note) -1; EP75F = ethylene-propylene-dicyclopentadiene terpolymer rubber (propylene 30% by weight, cyclopentadiene 20% by weight) manufactured by Nippon Synthetic Rubber Co., Ltd. Note 2) ADEKA STAB LA-77 = Screw (2, 2,
6,6-tetramethyl-4-piperidyl) sebacate,
Adekastab LA-62 = 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4
A condensate of piperidinol and tridecyl alcohol,
Adekastab LA-67 = 1,2,3,4-butanetetracarboxylic acid, condensate of 2,2,6,6-tetramethyl-4-piperidinol and tridecyl alcohol, Adekastab LA-63 = 1,2,2 3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-
Condensation product with 3,9- (2,4,8,10-tetraoxaspiro [5,5] undecane) diethanol, ADK STAB LA-68 = 1,2,3,4-butanetetracarboxylic acid and 2,2 , 6,6-Tetramethyl-4-piperidinol and β, β, β ', β'-tetramethyl-3,9
-(2,4,8,10-tetraoxaspiro [5,5]
Undecane) Condensate with diethanol Above, manufactured by Asahi Denka Kogyo Co., Ltd. Note 3) Acryester ED = ethylene glycol dimethacrylate manufactured by Mitsubishi Rayon Co., Ltd., Hicross M
= Trimethylolpropane trimethacrylate Seiko Chemical Co., Ltd., TAIC = triallyl isocyanurate Nippon Kasei Co., Ltd. Note-4); PE-3A = pentaerythritol triacrylate Kyoeisha Yushi Kagaku Co., Ltd. Note-5) IRGANOX 1076 = octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate CIBA-GEIGY CO., LTD.

[0020]

[Table 2]

As is apparent from Tables 1 and 2, Examples 1 to
As for No. 5, it can be seen that a vulcanization rate is rapid, and a crosslinked product excellent in heat resistance and compression set (particularly, FIG. 1 [II] plate-shaped tube shape) can be obtained. On the other hand, Comparative Examples 1 to 6
It can be seen that each of them has a very large compression set in FIG.

[0022]

The ethylene-propylene copolymer rubber composition of the present invention has no surface tackiness even when continuously crosslinked in hot air, and has heat resistance and compression set characteristics (particularly in thin product shapes). The crosslinked product excellent in (1) is obtained. This crosslinked product is
EPDM for automotive water hoses, window frames, door seal sponges, trunk lids, laminated and extruded rubber products of solid rubber and sponge rubber, glass run channels, other various weather strips, building material gaskets, waterproof sheets, roofing, electric wires, etc. Used for rubber products manufactured by extrusion. Furthermore, the composition of the present invention is excellent in crosslinkability in the presence of air, and even in a molded product, a portion in contact with air such as burrs is sufficiently crosslinked,
It can be used optimally without problems such as mold adhesion. Mold products include window frames, various boots, caps,
It can be used for any rubber product applications where EPDM or other rubbers are used, such as cups, vibration isolating rubbers, rolls, etc.

[Brief description of the drawings]

FIGS. 1 [I], [II] and [III] show the shape of a die attached to an extruder used for molding unvulcanized rubber.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Itsuki Umeda 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-64-75552 (JP, A) 4-261434 (JP, A) JP-A-4-293946 (JP, A) JP-B 64-2139 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 23/00 -23/36 C08K 3/00-13/08 C08J 3/24

Claims (2)

(57) [Claims] 1. An organic peroxide of (B) 0.01 to 100 parts by weight of (A) an ethylene-propylene copolymer rubber.
Ethylene-propylene resin containing 10 parts by weight, (C) 0.01 to 10 parts by weight of an acrylate compound having a plurality of acryloyl groups , and (D) 0.01 to 10 parts by weight of a hindered amine compound. Polymerized rubber composition. 2. The (C) acrylate compound having a plurality of acryloyl groups comprises ethylene glycol diacrylate, trimethylolpropane triacrylate, triethylene glycol diacrylate, polyoxyethylene diacrylate and pentaerythritol triacrylate. At least one selected from the group
The ethylene-propylene-based copolymer rubber composition according to claim 1, which is a compound of a kind.