Ethylene-isoprene random copolymer

Details Ethylene-isoprene random copolymer Ethylene-isoprene random copolymer

1999-03-03

2001-09-11

Wu, David W. (Department: 1713)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Polymers from only ethylenic monomers or processes of...

C526S132000, C526S134000, C526S160000, C526S340200, C526S943000

Reexamination Certificate

active

06288191

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ethylene-isoprene random copolymer, an elastomer composition and a cross-linked elastomer composition. More particularly, the present invention relates to an ethylene-isoprene random copolymer having a fast cure rate and a high crosslinking density, an elastomer composition and a cross-linked elastomer composition obtained by using said ethylene-isoprene random copolymer. The term “random copolymer” as used herein refers to a copolymer in which an arrangement of monomer units is random (see, “Essential Highpolymer Science”, page 21, published by Kodansha, written by Seiichi Nakahama et al.).
2. Description of Related Art
Heretofore, JP-B-48-56775 disclosed a process for producing an ethylene-isoprene amorphous copolymer using a vanadium chloride compound, and an ethylene-isoprene copolymer having an isoprene content of 50-80% by mole obtained by said process. In addition, Dong-Ho Lee et al disclosed a process for producing an ethylene-isoprene copolymer using ethylenebisindenylzirconium dichloride (Et(Ind)
2
ZrCl
2
) modified methylaluminoxane catalyst system, and an ethylene-isoprene copolymer having an isoprene content of 0.9% by mole obtained by said process (Eur. Polym. Jour., Vol. 33, No. 4, pp. 447, 1997). However, no ethylene-isoprene copolymer having a fast cure rate and a high crosslinking density has been known.
SUMMARY OF THE INVENTION
The present inventors have conducted extensive studies for obtaining an ethylene-isoprene random copolymer having the characteristics of a fast cure rate and a high crosslinking density. As the result, the present inventors have found that an ethylene-isoprene random copolymer having an isoprene content of about 1 to 45% by mole has a fast cure rate and a high crosslinking density, and have thus completed the present invention. The fast cure rate enables a decrease in costs for vulcanization steps or in post cure, as well as decrease the amount of vulcanization agent needed to be used. In addition, the high crosslinking density brings advantages, in that the provided copolymer allows for the production of a sponge rubber that is highly foamed and has a high stiffness, which it is excellent in low-temperature setting property and oil resistance and that allows for high filling, thereby also allowing for a decrease in costs.
Accordingly, the present invention relates to an ethylene-isoprene random copolymer having an isoprene content of about 1 to 45% by mole, or an ethylene-isoprene copolymer having a Q-value of about 3.5 or less, wherein the Q-value is a ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn).
The present invention also relates to an elastomer composition comprising about 100 parts by weight of said ethylene-isoprene random copolymer, about 5 to 400 parts by weight of an inorganic filler and/or carbon black and about 0.1 to 20 parts by weight of a cross-linking agent.
The present invention also relates to a cross-linked elastomer composition obtained by cross-linking said elastomer composition.


REFERENCES:
patent: 3883493 (1975-05-01), Yamao et al.
patent: 3935175 (1976-01-01), Lugli et al.
patent: 4035444 (1977-07-01), Yang
patent: 4288581 (1981-09-01), Wieder et al.
patent: 6084046 (2000-07-01), Johoji et al.
patent: 0 283 067 A1 (1988-09-01), None
patent: 48-56775 (1973-08-01), None
Lee et al., Copolymerizations of Olefins and Dienes with Homogeneous and Heterogeneous Catalysts, Eur. Polym. J. 33(4), pp. 447-451, 1997.*
Patent Abstracts of Japan C-165, p. 51, JP 58-029893 A (Nippon Yushi K. K.) Feb. 22, 1983.
Derwent Abstract Accession No. 91-129570, Class A35, JP 3-069342 A (Mitsubishi Kasei Corp) Aug. 9, 1989.
Derwent Abstract Accession Accession No. 94-012332, Class A17, JP 5-320259 A (Idemitsu Kosan Co Ltd) Dec. 3, 1993.
Derwent Abstract Accession No. 96-422009, Class A17, JP 8-208732 A (Sumitomo Chem Co Ltd) Aug. 13, 1996.
Lee, et al., “Copolymerizations of Olefins and Dienes with Homogeneous and Heterogeneous Catalysts”, Eur. Polym. J., vol. 33, No. 4, 1997, pp. 447-451.

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