JP2001214011A - Rubber composition and vulcanized rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition containing an ethylene-α-olefin copolymer rubber or an ethylene-α-olefin-non-conjugated diene copolymer rubber as a rubber component and having satisfactory vulcanizability. Provided are a rubber composition capable of obtaining a vulcanized rubber composition excellent in heat resistance while maintaining a required level, and a vulcanized rubber composition obtained by vulcanizing the rubber composition. SOLUTION: The rubber composition contains the following components (A) to (E). (A): ethylene-α-olefin copolymer rubber or ethylene-α-olefin-non-conjugated diene copolymer rubber
100 parts by weight (B): amine-based antioxidant 0.01 to 10 parts by weight (C): sulfur-based antioxidant or phosphorus-based antioxidant 0.0
1 to 10 parts by weight (D): hindered amine-based weathering agent 1 to 20 parts by weight (E): organic peroxide

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a rubber composition and a vulcanized rubber composition. More specifically, the present invention relates to a rubber composition comprising an ethylene-α-olefin copolymer rubber or an ethylene-α olefin-non-conjugated diene copolymer rubber as a rubber component, which should satisfy vulcanizability. The present invention relates to a rubber composition capable of obtaining a vulcanized rubber composition which is maintained at a standard and has excellent heat resistance, and a vulcanized rubber composition obtained by vulcanizing the rubber composition.

[0002]

2. Description of the Related Art Ethylene-α-olefin copolymer rubbers represented by ethylene-propylene copolymer rubber or ethylene-propylene-non-conjugated diene copolymer rubber are used for applications such as automobile parts and building materials. Widely used. By the way, an anti-aging agent is used in rubber products in order to prevent property deterioration during use. In recent years, the required level of heat resistance has become more and more severe. However, if a large amount of an antioxidant is used to enhance antiaging properties, the expected improvement effect cannot be obtained and vulcanization properties are not improved. However, there was a problem that was reduced. In particular, it deteriorates the sealing property, which is an important property as a rubber product. That is, a rubber composition containing an ethylene-propylene copolymer rubber or an ethylene-propylene-non-conjugated diene-based copolymer rubber as a rubber component, maintaining vulcanizability at a satisfactory level, and improving heat resistance. A rubber composition capable of obtaining an excellent vulcanized rubber composition and a vulcanized rubber composition obtained by vulcanizing the rubber composition have been desired.

[0003]

Under these circumstances, the problem to be solved by the present invention is to provide a rubber containing an ethylene-propylene copolymer rubber or an ethylene-propylene-nonconjugated diene copolymer rubber as a rubber component. A rubber composition capable of obtaining a vulcanized rubber composition having a satisfactory vulcanizability at a satisfactory level and having excellent heat resistance, and a vulcanizable composition obtained by vulcanizing the rubber composition. It is to provide a vulcanized rubber composition.

[0004]

Namely, one aspect of the present invention relates to a rubber composition containing the following components (A) to (E). (A): ethylene-α-olefin copolymer rubber or ethylene-α-olefin-non-conjugated diene copolymer rubber
100 parts by weight (B): amine-based antioxidant 0.01 to 10 parts by weight (C): sulfur-based antioxidant or phosphorus-based antioxidant 0.0
1 to 10 parts by weight (D): hindered amine-based weather resistance imparting agent 1 to 20 parts by weight (E): organic peroxide Another invention of the present invention is obtained by vulcanizing the above rubber composition. The vulcanized rubber composition to be used.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The component (A) of the present invention is an ethylene-α-olefin copolymer rubber or an ethylene-α-olefin-nonconjugated diene copolymer rubber.

Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene,
-Methyl-1-pentene, 1-octene, 1-decene and the like, and propylene and 1-butene are usually used.

As non-conjugated dienes, for example, 1,4
-Hexadiene, 1,6-octadiene, 2-methyl-
Linear non-conjugated dienes such as 1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene; cyclohexadiene, dicyclopentadiene, methyltetraindene, 5-vinylnorbornene 2,3-diisopropylidene-5-cyclic non-conjugated dienes such as, 5-ethylidene-2-norbornene and 6-chloromethyl-5-isopropylenyl-2-norbornene
Norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, 1,3,7-octatriene, 1,4,9
A triene such as decatriene, one of which may be used alone, or two or more of which may be used in combination; In addition, from the viewpoint of copolymerization reactivity and crosslinking reaction rate, 5
-Ethylidene-2-norbornene and / or 5-ethylidene-2-norbornene and dicyclopentadiene are preferred.

The ratio (molar ratio) of ethylene / α-olefin in ethylene-α-olefin copolymer rubber or ethylene-α-olefin-non-conjugated diene copolymer rubber
Is usually 1 / (0.1 to 1). As for the non-conjugated diene, the ratio (molar ratio) of ethylene / non-conjugated diene is usually set to 1 / (0.005 to 0.2).

The component (B) of the present invention is an amine-based antioxidant, and specifically, naphthylamine-based phenyl-α-
Naphthylamine, diphenylamine-based 4,4'-dioctyldiphenylamine, phenylenediamine-based N-
Examples thereof include isopropyl-N'-phenyl-p-phenylenediamine and quinoline-based 2,2,4-trimethyl-1,2-dihydroquinoline condensate. (B)
May be used alone or in combination of two or more.

The amount of (B) used is 0.01 to 10 parts by weight of (B) per 100 parts by weight of (A), and preferably 0.5 to 4 parts by weight of (B). If the content of (B) is too small, the effect of improving heat resistance is poor. On the other hand, if the content of (B) is too large, no further improvement in the effect of improving heat resistance is observed, which is uneconomical. Discoloration is not preferred. The amount of (B) when two or more kinds are used in combination as (B) is based on the total amount.

The component (C) of the present invention is a sulfur-based anti-aging agent or a phosphorus-based anti-aging agent.

Examples of the sulfur-based anti-aging agent include pentaerythritol-tetrakis- (3-laurylthiopropionate) and dilauryl-3,3'-thiodipropionate having a thiopropionate or thiodipropionate group. Further, mercaptobenzimidazole and its zinc salt can be exemplified.

The phosphorus antioxidant is a phosphorus compound having a phosphite ester bond containing a trivalent phosphorus atom, such as trisnonylphenylphosphate, triphenylphosphate, tris (2,4-di-tertiary). (Butyl) phosphate and the like.

As (C), one type may be used alone, or two or more types may be used in combination.

The amount of (C) used is 0.01 to 10 parts by weight of (C) per 100 parts by weight of (A), and preferably 0.5 to 8 parts by weight of (C). If the content of (C) is too small, the effect of improving heat resistance is poor. On the other hand, if the content of (B) is too large, no further improvement in the heat resistance improving effect can be seen, which is uneconomical. Discoloration is not preferred. The amount of (C) when two or more kinds are used as (C) is based on the total amount.

The component (D) of the present invention is a hindered amine-based weathering agent, and has a substituent at the 4-position.
It is a 6,6-tetraalkylpiperidine derivative. Examples of the substituent at the 4-position include various groups such as a carboxylic acid residue, an alkoxy group, and an alkylamino group, and the N-position may be substituted with an alkyl group. Specifically, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine succinate polycondensate, poly [[6- (1,
(1,3,3-tetramethylbutyl) imino-1,3,5
-Triazine-2,4-diyl] [(2,2,6,6-
Tetramethyl-4-pyridyl) iminohexamethylene [[2,2,6,6-tetramethyl-4-piperidyl]
Imino]], N, N'-bis (3-aminopropyl) ethylenediamine.2,4-bis [N-butyl-N-
(1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like. As (D), one type may be used alone, or two or more types may be used in combination.

The amount of (D) used is 1 to 20 parts by weight of (D) per 100 parts by weight of (A), preferably (D) 2
To 10 parts by weight. If the amount of (D) is too small, the effect of improving heat resistance is poor, while if the amount of (B) is too large, no further improvement in the effect of improving heat resistance can be seen, which is uneconomical and the mechanical properties of the vulcanized rubber are poor. It is not preferable because it lowers. In addition,
The amount of (D) when two or more of (D) are used in combination is
Based on the total amount.

The component (E) of the present invention is an organic peroxide, which is not particularly limited, and may be any of those commonly used for vulcanizing ethylene-α-olefin copolymerized rubber. Examples include dicumyl peroxide, benzoyl peroxide, 1,1-di-t-butylperoxy-
3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-
3, and 1,3-di (t-butylperoxyisopropyl) benzene. The amount of (E) used is 1 to 8 parts by weight of (E) per 100 parts by weight of (A). If necessary, ethylene glycol dimethacrylate, trimethylpropane trimethacrylate, triallyl isocyanurate, N, N'-m-phenylenebismaleimide, and the like can be added as a co-crosslinking agent for (E).

The method for obtaining the rubber composition of the present invention includes:
You can do the following: That is, (A),
(B), (C), (D) and, if necessary, reinforcing agents such as carbon black and silica, softeners such as process oils, activators such as polyethylene glycol and stearic acid, and processing aids such as fatty acid metal salts. A compound is obtained by kneading an agent, a vulcanization accelerating aid such as zinc oxide, a white filler (extender) such as calcium carbonate, etc. using a Banbury or a kneader. Next, the organic peroxide (E) and, if necessary, a co-crosslinking agent are added to the compound, and the mixture is kneaded using an open roll, a kneader, or the like to obtain the rubber composition of the present invention.

The vulcanized rubber composition of the present invention can be obtained by vulcanizing the above rubber composition of the present invention. As a vulcanization method, for example, a hot press method, a molten salt heating method, or the like can be used. The vulcanization conditions include, for example, temperature 1
30 to 200 ° C. for a time of 1 to 60 minutes.

The vulcanized rubber obtained by vulcanizing the rubber composition of the present invention can be used for sealing rubber for automobiles and buildings, waterproof sheets,
It can be used especially optimally in the fields of belts, hoses, rubber plates, rubber vibration insulators, rolls and the like.

[0022]

Next, the present invention will be described by way of examples. Examples 1 to 7 As (A), 100 parts by weight of an ethylene-α-olefin-non-conjugated diene copolymer rubber and carbon black, hydrotalcite,
Clay, light calcium carbonate, silica, talc, process oil, zinc oxide, polyethylene glycol; (B) an amine antioxidant; (C) a sulfur antioxidant; and (D) a hindered amine weathering agent. The compound was obtained by kneading with a Banbury mixer. Next, a rubber composition was obtained by adding and kneading an organic peroxide and a co-crosslinking agent as (E) to the compound using an open roll. Next, it was vulcanized using a hot press to obtain a vulcanized product. Vulcanization conditions are 170
C. × 15 minutes. The obtained vulcanized rubber was measured and evaluated for the items in Table 2 or Table 3. 200% modulus, 3
00% modulus, tensile strength, tensile elongation are JIS
K 6251, hardness to JIS K 6253, compression set to JIS K 6262, aging test to JIS K
6257. The results are shown in Table 2 or Table 3. The heat resistance was evaluated based on the tensile elongation change rate and the hardness change value after the aging test.

Comparative Examples 1 to 3 The kneading was carried out using a Banbury mixer without adding an amine antioxidant as (B), a sulfur antioxidant as (C) or a hindered amine weathering agent as (D). , And in the same manner as in Examples. Formulation examples are shown in Table 1 or Table 2, and measurement results are shown in Table 2.

In the results of Table 2, Comparative Example 1 using only the amine antioxidant (B) and the sulfur antioxidant (C) shows the evaluation results of the physical properties of the conventionally used heat-resistant compound. is there. Even if the amount of the antioxidant is increased as in Comparative Example 2 in order to further improve the heat resistance, the improvement in the rate of change in tensile elongation and the value of the change in hardness cannot be obtained, indicating that it is difficult to improve the heat resistance. In addition, compression set, which is an important characteristic of rubber products and an indicator of sealability, deteriorates. On the other hand, even when the antiaging agent is not used and only the hindered amine-based weathering agent (D) is added as in Comparative Example 3, good heat resistance cannot be obtained. On the other hand, the composition containing (B) an amine-based antioxidant, (C) a sulfur-based antioxidant, and (D) a hindered amine-based weather resistance imparting agent shown in Examples is more heat resistant than Comparative Example. It can be seen that the indices of tensile elongation change and hardness change are excellent. The compression set and other properties are maintained at a satisfactory level.

[0025]

[Table 1] Common formulation (parts by weight)

[0026]

[Table 2] Formulas (parts by weight) other than common formulas and results

[0027]

[Table 3] Formulas (parts by weight) other than common formulas and results

* 1 Esplene 521F manufactured by Sumitomo Chemical Co., Ltd. (Mooney viscosity ML _{1 + 4} 125 ° C. 66, ethylene content 65% by weight, diene content 4.0% by weight) * 2 Esplene 532 manufactured by Sumitomo Chemical Co., Ltd. (Mooney viscosity ML _{1 + 4} 125 ° C 81, ethylene content 51
* 3 Asahi # 50U manufactured by Asahi Carbon Co., Ltd. * 4 DHT4A manufactured by Kyowa Chemical Industry Co., Ltd. * 5 Crown clay manufactured by South Easterm * 6 Silver W manufactured by Shiraishi Industry Co., Ltd. * 7 Nipseal VN3 manufactured by Nippon Silica Kogyo Co., Ltd. * 8 Mistron Vapor manufactured by Nippon Mistron Co., Ltd. * 9 PW380 manufactured by Idemitsu Kosan Co., Ltd. * 10 Parkmill D (Jimyl peroxide) manufactured by Nippon Yushi Co., Ltd. * 11 Trial Eucyanurate * 12 Antigen RD (2, manufactured by Sumitomo Chemical Co., Ltd.)
* 13 Sumilizer MB (mercaptobenzimidazole) manufactured by Sumitomo Chemical Co., Ltd. * 14 TIN manufactured by Ciba Specialty Chemicals Co., Ltd.
UVIN622LD (Dimethyl succinate-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-
Tetramethylpiperidine polycondensate) * 15 Sanol LS944 (poly [[6
-(1,1,3,3-tetramethylbutyl) imino-
1,3,5-triazine-2,4-diyl] [(2
2,6,6-tetramethyl-4-pyridyl) iminohexamethylene [[2,2,6,6-tetramethyl-4-piperidyl] imino]]) * 16 CHI manufactured by Ciba Specialty Chemicals Co., Ltd.
MASSORB 119FL (N, N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-
Piperidyl) amino] -6-chloro-1,3,5-triazine condensate)

[0029]

As described above, according to the present invention, the ethylene-α-olefin copolymer rubber or ethylene-α
A rubber composition containing an olefin-non-conjugated diene copolymer rubber as a rubber component, which can provide a vulcanized rubber composition which maintains vulcanizability at a satisfactory level and has excellent heat resistance. A rubber composition and a vulcanized rubber composition obtained by vulcanizing the rubber composition could be provided.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08K 5/36 C08K 5/36 5/521 5/521 C08L 23/16 C08L 23/16 F term (reference) 4F070 AA13 AA16 AC46 AC50 AC55 AC56 AE03 AE08 GA05 GB02 GB07 GC02 GC03 GC04 4J002 BB051 BB151 EK039 EK049 EN066 EN076 EU078 EU088 EV067 EW047 FD076 FD077 FD088 FD149

Claims (2)

[Claims] 1. A rubber composition containing the following components (A) to (E). (A): ethylene-α-olefin copolymer rubber or ethylene-α-olefin-non-conjugated diene copolymer rubber
100 parts by weight (B): amine-based antioxidant 0.01 to 10 parts by weight (C): sulfur-based antioxidant or phosphorus-based antioxidant 0.0
1 to 10 parts by weight (D): hindered amine-based weathering agent 1 to 20 parts by weight (E): organic peroxide 2. A vulcanized rubber composition obtained by vulcanizing the rubber composition according to claim 1.