Mitsui Petrochemical Industries, Ltd.

Mitsui Chemicals, Inc.

Other

Shin-etsu Chemical Co., Ltd.

Toyoda Gosei Co., Ltd.

Central Glass Company, Limited

Nippon Oil Fats Co., Ltd.

Rikagaku Kenkyusho

Hidenari Nakahama

Masaaki Kawasaki

Tetsuo Tojo

Toshihiro Sagane

Toshiyuki Tsutsui

Mikio Hosoya

Yuji Ishii

Takashi Mishima

Keiji Okada

Noriaki Kihara

Seizo Miyata

Takashi Hakuta

Kyoko Kobayashi

Taku Koda

Masaaki Yasuda

Shuichi Nonaka

Tatsuyoshi Ishida

Hitoshi Onishi

Tsutomu Nakamura

Siegfried Wolff

Takeo Yoshida

Yoshiharu Kikuchi

Kotaro Ichino

Yuichi Ito

Yoshishige Murata

Toshimasa Takata

Katsumi Nakashima

Satao Hirabayashi

Katsuya Takahashi

Tomoaki Okita

Mitsunao Arino

Shinya Matsunaga

Akira Yamada

Yasuhiro Hosomi

Kiyotaka Shigehara

Kiyoshi Honma

Mitsuhiko Onda

Marinus Haddeman

Masahiko Hara

Hiroshi Kameda

Tosiaki Kimura

Takasi Misima

Totshiyuki Tsutsui

Rainer Panenka

Takeshi Kasuga

Yuji Miura

Yoshio Maejima

An object of the present invention is to provide an olefin-based thermoplastic elastomer composition that has both weatherability and flexibility at low temperatures, is excellent in fluidity, and causes no stickiness even in the use at high temperatures; a process oil composition for elastomers that serves as the raw material of the thermoplastic elastomer composition and contributes to the above characteristics; and an oil-extended elastomer containing the process oil composition. The process oil composition for elastomers of the present invention has a property that, when 20 parts by weight of the process oil composition for elastomers are blended with respect to 100 parts by weight of a propylene homopolymer, the melting point of the propylene homopolymer is lowered by 2 to 4.5&#xb0; C. compared to that of the propylene homopolymer without blending. The process oil composition for elastomers is a mixture of a purified mineral oil and a synthetic oil obtained by polymerizing (an) olefinic monomer(s), wherein the ratio of the purified mineral oil to the synthetic oil is preferably 40/60 to 80/20.

Process oil composition, oil-extended elastomer containing the same and olefin-based thermoplastic elastomer composition

The present invention provides a vulcanized foamed rubber molded product which has surface smoothness equal to or higher than that of a non-foamed vulcanized rubber molded product, has excellent mechanical strength properties, compression set resistance and abrasion resistance and a non-foamed vulcanized rubber molded product which is superior in surface smoothness to a conventional non-foamed vulcanized rubber molded product and has excellent compression set resistance, mechanical strength properties and abrasion resistance, as well as a method of producing the same. The molded product of the present invention is characterized in that the amount of sulfur atoms present in the surface thereof is at least 1.2 times as high as the amount of sulfur atoms present in a cut face obtained by cutting the surface to a depth of 1.0 mm in the vertical direction. The method of producing comprises allowing droplets or spray of a liquid containing an elementary substance consisting of a non-oxygen element in the group VI in the periodic table to adhere to the surface of a non-vulcanized rubber composition containing an elemental sulfur and/or a sulfur compound as a crosslinking agent, and then vulcanizing or vulcanizing and foaming the composition.

Vulcanized rubber molded product, method of producing the same, and use of the molded product

This invention relates to a composition comprising (A) an ethylene-&#x3b1;-olefin having 3 to 20 carbon atoms-non-conjugated polyene copolymer, (B) a specific fine-powdered silicic acid and/or a silicate having a specific surface area of 5 to 500 m/g (BET adsorption amount: ISO 5794/1, Annex D), (C) at least one kind of &#x3b1;,&#x3b2;-unsaturated carboxylic acid metal salts, (D) an organic peroxide, further optionally (E) one antioxidant selected from sulfur-containing antioxidants, phenolic antioxidants and amine antioxidants, and/or (F) sulfur, and this invention relates to a rubber product obtainable by crosslinking the above composition.

Rubber compositions and their uses

The crosslinkable rubber composition of the invention is crosslinkable by hot air, and a hot-air crosslinked rubber sheet thereof has no scratch on the surface in a hardness test using a pencil of HB and has a compression set of not more than 70% after a heat treatment at 150&#xb0; C. for 22 hours. The rubber composition comprises an ethylene/&#x3b1;-olefin/non-conjugated polyene random copolymer rubber comprising a specific vinyl end group-containing norbornene compound, a SiH group-containing compound having at least two SiH groups in one molecule, and if necessary, an addition reaction catalyst comprising a platinum group element and a reaction inhibitor. The automobile weatherstrip, hose, rubber vibration insulator, belt, sealing material, expanded product, covered electric wire, electric wire joint, electric insulating part and household rubber product according to the invention comprise the above-mentioned rubber composition. The rubber composition has a high crosslinking rate and excellent productivity to produce crosslinked rubber molded products, is capable of undergoing hot-air crosslinking such as HAV or UHF and is capable of providing crosslinked rubber molded products having excellent compression set resistance, strength properties, heat resistance, weathering resistance and abrasion resistance.

Crosslinkable rubber compositions and use thereof

Rubber composition for extrusion molding and for molding with mold and use thereof

Rubber composition for a conveyor belt

A rubber composition is disclosed containing an ethylene-propylene-nonconjugated diene copolymer rubber (or a blend of an ethylene-propylene-nonconjugated diene copolymer rubber and a diene rubber), a specific alkoxysilane compound, and amorphous silica powder having a specific surface area of 50 to 100 m /g (BET adsorption). The vulcanized rubber is prepared by vulcanizing such a rubber composition. The rubber composition is excellent in dynamic characteristics and also in mechanical characteristics, dynamic fatigue resistance and thermal aging resistance. It also can provide a vulcanized rubber having the above-mentioned effects.

Vulcanizable EPDM containing rubber composition

Kneaded rubber for expandable formulation

Rubber composition and process for the production thereof

Chain polyene group-containing norbornene compound and unsaturated

A terpolymer rubber prepared from ethylene, .alpha.-olefin having 3 to 20 carbon atoms and branched chain polyene of the formula ##STR1## wherein R.sup.1 represents C.sub.1 -C.sub.5 alkyl, and R.sup.2 and R.sup.3 represent hydrogen atom or C.sub.1 -C.sub.5 alkyl, such as, for example, 6,7-dimethyl-4-ethylidene-1,6-octadiene, 6,7-dimethyl-4-ethylidene-1,6-nonadiene, and 9-methyl-4-ethylidene-1,8-decadiene; when added to a rubber (diene rubber, nitrile rubber or random copolymer rubber from ethylene, C.sub.3 -C.sub.20 .alpha.-olefin, and optionally a nonconjugated diene) provides curable rubber compositions having rapid vulcanization rates, for example, as lows as about 7 to 10 seconds. The diene rubber compositions also have excellent resistances to weather,ozone and heat aging while maintaining excellent mechanical strength characteristics. The nitrile rubber compositions also have excellent oil resistance.

Ethylene/.alpha.-olefin/nonconjugated polyene terpolymer rubber

The ethylene/.alpha.-olefin/nonconjugated polyene copolymer rubber composition of the present invention comprises in specified proportions a crystalline polyolefin resin (A) and an ethylene/.alpha.-olefin/nonconjugated polyene copolymer rubber (B) composed of ethylene, an .alpha.-olefin having 3 to 20 carbon atoms and a specific branched chain polyene compound. The molar ratio of ethylene units to .alpha.-olefin units, iodine value and intrinsic viscosity �.eta.! of the ethylene/.alpha.-olefin/nonconjugated polyene copolymer rubber (B) are within respective specified ranges. This rubber composition is excellent in low temperature properties. When the above olefinic thermoplastic elastomer composition is partially or entirely crosslinked, a molding can be provided which is superior to the conventional vulcanized rubbers in low temperature properties, tensile strength, elongation at break and rubber properties.

Ethylene/.alpha.-olefin/nonconjugated polyene copolymer rubber

A novel unsaturated copolymer of ethylene comprises a random copolymer of (i) ethylene, (ii) an .alpha.-olefin of 3 to 20 carbon atoms and (iii) at least one straight chain or branched chain nonconjugated triene or tetraene having one vinyl group in the molecule, which contains 30-92% by mol of ethylene units (i), 6-70% by mol of .alpha.-olefin units (ii) and 0.1-30% by mol of triene or tetraene units (iii), and which has a molar ratio of ethylene units (i) to .alpha.-olefin units (ii) of 40/60 to 92/8 (ethylene units (i)/.alpha.-olefin units (ii)) and an intrinsic viscosity (.eta.), measured in Decalin at 135.degree. C., of 0.05 to 10 dl/g. This novel unsaturated copolymer of ethylene is excellent in weathering resistance, heat resistance and ozone resistance and has a high vulcanizing rate.

Unsaturated copolymer of ethylene and process for preparing the same

Disclosed is a process for preparing an ethylene-.alpha.-olefin-nonconjugated polyene random copolymer comprising random copolymerizing (a) ethylene, (b) an .alpha.-olefin of 3 or more carbon atoms and (c) a nonconjugated polyene in the presence of a metallocene catalyst containing a specific metallocene compound. The ethylene-.alpha.-olefin-nonconjugated polyene random copolymer prepared by the process has such properties that (i) the copolymer contains units derived from ethylene (a) and units derived from the .alpha.-olefin of 3 or more carbon atoms (b) in a molar ratio of 40/60 to 95/5 �(a)/(b)!, (ii) the iodine value is 1 to 50, (iii) the intrinsic viscosity (.eta.) is more than 0.1 dl/g and less than 8.0 10 dl/g, (iv) the intensity ratio D of T.alpha..beta. to T.alpha..alpha. in the .sup.13 C-NMR spectrum, T.alpha..beta./T.alpha..alpha., is not more than 0.5, (v) the B value is 1.00 to 1.50, (vi) the glass transition temperature Tg is not higher than -50.degree. C., and (vii) the ratio g.eta.* of the intrinsic viscosity (.eta.) of this copolymer defined above to the intrinsic viscosity (.eta.).sub.blank of a straight-chain ethylene-propylene copolymer having the same weight-average molecular weight as this random copolymer and having an ethylene content of 70% by mol, (.eta.)/(.eta.).sub.blank, is more than 0.9. Also disclosed is a vulcanizable rubber composition containing the random copolymer. The ethylene-.alpha.-olefin-nonconjugated polyene random copolymer and the rubber composition are excellent in mechanical strength, weathering resistance, ozone resistance, processability, low-temperature flexibility and heat resistance.

Vulcanizable rubber composition containing

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Ichihara, Japan

Hidenari Nakahama