JP2002275334A - Rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contain an ethylene-α-olefin-non-conjugated polyene-based copolymer rubber, carbon black, a process oil having a sulfur content of 100 ppm by weight or less and an organic peroxide added at the time of kneading, and have a strength. The present invention provides a rubber composition which maintains various properties such as compression set and processability at a sufficiently satisfactory level, and has excellent oil resistance and heat resistance at high temperatures. SOLUTION: The following component (A) 100 parts by weight, (B)
A rubber composition containing 180 to 300 parts by weight, (C) 50 to 300 parts by weight, and (D) 5 to 10 parts by weight. (A): an ethylene-α-olefin-non-conjugated polyene-based copolymer rubber having a molar ratio of ethylene / α-olefin of 0.75 / 0.25 to 0.90 / 0.10; An ethylene having 3 to 10 carbon atoms, an iodine value of 12 to 30 and an intrinsic viscosity [η] of 2.3 to 5 measured in tetralin at 135 ° C.
α-olefin-non-conjugated polyene copolymer rubber (B): carbon black (C): process oil with a sulfur content of 100 ppm by weight or less added during kneading (D): organic peroxide

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a rubber composition. More specifically, the present invention relates to ethylene-α
-Olefin-non-conjugated polyene copolymer rubber, carbon black, sulfur content 100 ppm by weight added during kneading
A rubber composition containing the following process oil and organic peroxide, maintaining strength, workability, compression set, and other properties at a sufficiently satisfactory level, and having excellent oil resistance and heat resistance at high temperatures and It is about the product.

[0002]

2. Description of the Related Art Ethylene-α-olefin-non-conjugated polyene copolymer rubber does not have an unsaturated group in the main chain and has higher heat resistance than general-purpose diene rubbers such as natural rubber and butadiene rubber. Because of its superiority, it is widely used in products such as automotive parts, automotive water hoses, weather strips, and electric wires. On the other hand, in recent years, the temperature in the engine room of an automobile has been increased due to reduction of the engine room due to expansion of a living space, front-wheel drive, measures against noise, compliance with exhaust gas regulations, and the like. Therefore, a rubber composition which does not swell in an oil such as an engine oil in a high-temperature atmosphere, that is, has excellent oil resistance at a high temperature and excellent heat resistance, and a product thereof have been required. However, for example, using a non-oil-extended ethylene-α-olefin-non-conjugated polyene-based copolymer rubber and vulcanizing a compound having a normal carbon black content has a limit in oil resistance at high temperatures. Needed to be improved.

[0003] Further, halogen-based rubbers are excellent in oil resistance, but recently, due to environmental problems and the like, replacement of halogen-free rubbers, for example, ethylene-α-olefin-non-conjugated polyene copolymer rubber, has been demanded. Is growing.

[0004]

Under these circumstances, the object of the present invention is to provide an ethylene-α-olefin-non-conjugated polyene copolymer rubber, carbon black, and a sulfur content of 100 wt. A rubber composition containing a process oil and an organic peroxide of not more than 1 ppm, maintaining various properties such as strength, processability, compression set, etc. at a sufficiently satisfactory level, and having excellent oil resistance and heat resistance at high temperatures. And the provision of such products.

[0005]

That is, the present invention relates to the following components (A): 100 parts by weight, (B): 180 to 300 parts by weight, (C) 50 to 300 parts by weight, and (D) 5 to 10 parts by weight. The present invention relates to a rubber composition containing a part. (A): an ethylene-α-olefin-non-conjugated polyene-based copolymer rubber having a molar ratio of ethylene / α-olefin of 0.75 / 0.25 to 0.90 / 0.10; An ethylene having 3 to 10 carbon atoms, an iodine value of 12 to 30 and an intrinsic viscosity [η] of 2.3 to 5 measured in tetralin at 135 ° C.
α-olefin-non-conjugated polyene copolymer rubber (B): carbon black (C): process oil with a sulfur content of 100 ppm by weight or less added during kneading (D): organic peroxide

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The (A) of the present invention comprises ethylene-α
An olefin-non-conjugated polyene-based copolymer rubber component, wherein the molar ratio of ethylene / α-olefin is 0.75 /
0.25 to 0.90 / 0.10, the α-olefin has 3 to 10 carbon atoms, the iodine value is 12 to 30, and the intrinsic viscosity [η] measured in tetralin at 135 ° C. Is 2.3 to 5, ethylene-α-olefin-
It is a non-conjugated polyene copolymer rubber.

The molar ratio of ethylene / α-olefin of (A) is 0.75 / 0.25 to 0.90 / 0.10.
Preferably it is 0.80 / 0.20 to 0.90 / 0.10. If the ethylene content is too low, the strength is low, while if the ethylene content is too high, the processability deteriorates.

The (A) α-olefin has 3 carbon atoms.
-10, for example, propylene, 1-butene, 1-
Pentene, 1-hexene, 4-methyl-1-pentene,
Examples thereof include 1-octene and 1-decene, and usually propylene and 1-butene are used.

The iodine value of (A) is from 12 to 30, preferably from 12 to 25. If the iodine value is too low, the oil resistance is poor, while if the iodine value is too high, the heat resistance is poor. Examples of the non-conjugated polyene include 1,4-hexadiene,
6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-
Linear non-conjugated dienes such as 1,6-octadiene;
Cyclic non-conjugated dienes such as cyclohexadiene, dicyclopentadiene, methyltetraindene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene; 2,3-diene Isopropylidene-5-norbornene,
2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene,
Trienes such as 1,3,7-octatriene and 1,4,9-decatriene are mentioned, and one kind thereof may be used alone, or two or more kinds may be used in combination. In addition, 5-ethylidene-2-norbornene and / or 5-ethylidene-2-norbornene and dicyclopentadiene are preferred from the viewpoint of copolymerization reactivity and crosslinking reaction rate.

The intrinsic viscosity [η] of (A) measured in tetralin at 135 ° C. is 2.3 to 5.0, preferably 2.5 to 4.0. If the intrinsic viscosity [η] is too low, the roll processability is inferior, while if the intrinsic viscosity [η] is too high, the roll processability becomes difficult.

[0011] (B) of the present invention is carbon black, and the type thereof is not limited.

The (C) of the present invention is a process oil having a sulfur content of 100 ppm by weight or less added during kneading, and is used for adjusting the hardness of a molded product. The sulfur content of the process oil added during kneading is preferably 20 ppm by weight or less. Regarding the extender oil added before the drying step after the production of (A), it is preferable that the sulfur content is small, but there is no limitation. If the sulfur content is excessive, vulcanization is hindered, resulting in reduced strength and reduced oil resistance.

(D) of the present invention is an organic peroxide,
There are no restrictions on the type. Among them, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, α, α′-bis (t-butylperoxyisopropyl) benzene, 1,1-bis (t -Butylperoxy) -3,3,5-trimethylcyclohexane and n-butyl-4,4-bis (t-butylperoxy) valerate are preferred in view of the relationship between vulcanization temperature and time.

The contents of (A) to (D) are as follows. (A) 100 parts by weight, (B) 180 to 300 parts by weight, (C) 50 to 300 parts by weight and (D) 5 to 10 parts by weight, preferably (A) 100 parts by weight, (B) 20
0 to 280 parts by weight, (C) 50 to 250 parts by weight, and (D) 5 to 8 parts by weight. Here, if (B) is too small, the oil resistance is not sufficiently improved, while if (B) is too large, the roll processability is poor. If the content of (C) is too small, the hardness may increase, and the workability may deteriorate. On the other hand, if the content of (C) is too large, the hardness may decrease and the roll processability may deteriorate. is there. When (D) is added to rubber, a rubber diluted to 40% is often used, and the content ratio in this case is 12.5 to 20 parts by weight. (D)
Is too small, the strength is low, while if (D) is too large, the elongation is low.

When (D) is used, a crosslinking aid is usually used in combination in order to improve the crosslinking efficiency. Examples of the crosslinking assistant include p, p'-dibenzoylquinonedioxyium, quinonedioxyium, triallyl cyanurate, ethylene glycol dimethacrylate, N, N'-m-phenylenebismaleimide, trimethylolpropanetripanyl Examples include methacrylate and metal acrylate. The content ratio is 1 to 8 parts by weight based on 100 parts by weight of (A).

In the present invention, it is effective to use a silane coupling agent. Examples of the silane coupling agent include vinyl-tris (2-methoxy-ethoxy) silane, γ-methacryloxypropyl-trimethoxysilane and the like.

Examples of the method for obtaining the rubber composition and the product thereof of the present invention include the following methods.
That is, (A), (B) and (C), and if necessary, activators such as polyethylene glycol and stearic acid, processing aids such as fatty acid metal salts, vulcanization accelerating aids such as zinc oxide, talc A compound is obtained by kneading a white filler (bulking agent) such as calcium carbonate and a physical property improving agent such as a silane coupling agent using a Banbury or a kneader. Next, in the compound:
The vulcanizing agent (D) and a cross-linking aid are combined with an open roll,
The compound of the rubber composition of the present invention can be obtained by kneading using a kneader or the like. In order to vulcanize the compound, for example, a heating press method, a hot air heating method, a high frequency heating method, a molten salt heating method, or the like can be used. As the vulcanization conditions, for example, a temperature of 150 to 2
00 ° C. for a time of 3 to 60 minutes, preferably 10 to 60 minutes.

The rubber composition and the product thereof of the present invention can be used particularly optimally in the fields of automotive hoses, automotive hose coverings, and air duct hoses.

[0019]

Next, the present invention will be described by way of examples. Example 1 EPDM from Oil Exhibit (EPDM manufactured by Sumitomo Chemical Co., Ltd., ethylene / propylene molar ratio: 0.82 / 0.18, non-conjugated polyene: 5-ethylidene-2-norbornene, iodine value: 15, Mooney viscosity: ML) _{1 + 4} 125 ° C 52, 135 ° C
170 parts by weight of intrinsic viscosity [η] 3.4 measured in tetralin, 70 parts by weight of extending oil, and 210 parts by weight of (B) carbon black (“Asahi 60G” manufactured by Asahi Carbon Co., Ltd.)
(C) 110 parts by weight of process oil (“PW380” manufactured by Idemitsu Co., sulfur content 6 ppm by weight), 3 parts by weight of stearic acid, 5 parts by weight of zinc oxide, polyethylene glycol # 40
Compound 2 was obtained by kneading 2 parts by weight of 00 and 2 parts by weight of a silane coupling agent (“A174” manufactured by Nippon Unicar, γ-methacryloxypropyl-trimethoxysilane) with a Banbury mixer. Next, an organic peroxide (“Park Mill D” manufactured by NOF Corporation) was added to the compound.
-40 ", 40% dicumyl peroxide) 15 parts by weight, and a crosslinking aid (" Acryester ED ", ethylene glycol dimethacrylate, manufactured by Mitsubishi Rayon Co., Ltd.)
A compound was obtained by adding and kneading 3.4 parts by weight using an open roll. Next, it was vulcanized using a hot press to obtain a vulcanized product. The vulcanization conditions were 160 ° C. × 40 minutes. The oil resistance test was performed at 125 ° C. for 70 hours using IRM903 as a test lubricant. 150 ℃ heat resistance test
For 70 hours. Other measurements and evaluations were performed on the items described in Tables 2 and 3. The results are shown in Tables 2 and 3.

Example 2 The organic peroxide of Example 1 was replaced with "Perhexa 2" manufactured by NOF Corporation.
5B-40 "(a 40% product of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane) and a cross-linking aid such as Nippon Kasei's" Tyke-M60 "(triallylcia). Vulcanization conditions are 170 ° C x
Except for 40 minutes, it was the same as Example 1.

Comparative Example 1 The procedure of Example 1 was repeated except that (C) of Example 1 was replaced with "PS-430" (sulfur content: 0.16 wt%) manufactured by Idemitsu Co., Ltd.

Comparative Example 2 The same procedure was performed as in Example 1 except that the amount of (D) was changed to 10 parts by weight.

Comparative Example 3 Non-oil-extended EPDM (EPDM manufactured by Sumitomo Chemical Co., Ltd., ethylene / propylene molar ratio 0.75 / 0.25, non-conjugated polyene 5-ethylidene-2-norbornene, iodine value 11 Mooney viscosity ML _{1 + 4} 125 ° C 66, 135
Using the intrinsic viscosity [η] 2.1) measured in tetralin at ℃, the compounding ingredients shown in Table 1 were kneaded. Vulcanization conditions are 170 ° C
× 20 minutes. Evaluation was performed in Examples 1 and 2 and Comparative Examples 1 and 2.
The same was done.

The following can be seen from the results. In Examples 1 and 2 in which (B), (C) and (D) were blended with (A),
Compared with Comparative Example 1 in which a process oil having a sulfur content of 0.16 wt% was used instead of (C), the physical properties in a normal state were maintained at a usable level and the oil resistance was improved. (D)
Comparative Example 2 in which the amount of added was reduced, compared to Example 1,
It can be seen that the oil resistance is poor. 135 ° C instead of (A)
EP with intrinsic viscosity [η] of 2.1 measured in tetralin
Comparative Example 3, in which 150 parts by weight of carbon black was mixed with DM, was remarkably inferior in oil resistance.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

As described above, according to the present invention, ethylene-α-olefin-non-conjugated polyene copolymer rubber, carbon black, sulfur content of 100 added at the time of kneading.
A rubber composition containing less than ppm by weight of process oil and organic peroxide, maintaining various properties such as strength, compression set, workability, etc., at a sufficiently satisfactory level, and having excellent oil resistance and heat resistance at high temperatures. I was able to provide things.

Claims (4)

[Claims] 1. 100 parts by weight of the following component (A), (B)
A rubber composition containing 180 to 300 parts by weight, (C) 50 to 300 parts by weight, and (D) 5 to 10 parts by weight. (A): an ethylene-α-olefin-non-conjugated polyene-based copolymer rubber having a molar ratio of ethylene / α-olefin of 0.75 / 0.25 to 0.90 / 0.10; An ethylene having 3 to 10 carbon atoms, an iodine value of 12 to 30 and an intrinsic viscosity [η] of 2.3 to 5 measured in tetralin at 135 ° C.
α-olefin-non-conjugated polyene copolymer rubber (B): carbon black (C): process oil with a sulfur content of 100 ppm by weight or less added during kneading (D): organic peroxide 2. The rubber composition according to claim 1, wherein the α-olefin of (A) is propylene. 3. The rubber composition according to claim 1, wherein the non-conjugated diene (A) is 5-ethylidene-2-norbornene and / or dicyclopentadiene. (D) is dicumyl peroxide, 2,
5-dimethyl-2,5-di (t-butylperoxy) hexane, α, α′-bis (t-butylperoxyisopropyl) benzene, 1,1-bis (t-butylperoxy) -3,3 The rubber composition according to claim 1, wherein the rubber composition is at least one member selected from the group consisting of 2,5-trimethylcyclohexane and n-butyl-4,4-bis (t-butylperoxy) valerate.