Shin-etsu Chemical Co., Ltd.

Mitsui Chemicals, Inc.

Other

Takeo Yoshida

Noriyuki Meguriya

Masaharu Takahashi

Syuuichi Azechi

Kunio Itoh

Susumu Sekiguchi

Hironao Fujiki

Tsutomu Nakamura

Masaaki Kawasaki

Yoshiharu Kikuchi

Kazutoshi Fujioka

Takashi Hakuta

Takashi Kondou

Masanobu Miyakoshi

Satao Hirabayashi

Yoshiteru Kobayashi

Manabu Narumi

Toshio Shiobara

Akira Yamamoto

Masatoshi Arai

Toshihide Shimizu

Yoshio Inoue

Motoo Fukushima

Toshio Shinohara

Toshio Yamazaki

Yoshifumi Inoue

Hidenari Nakahama

Shigeki Shudo

Osamu Hayashida

Tamaki Iida

Mikio Hosoya

Nobumasa Tomizawa

Kiyoshi Imai

Yuji Ishii

Mitsunao Arino

Taku Koda

Yujiro Taira

Kenichi Takita

Shuichi Nonaka

Masaya Arakawa

Ken-ichi Takita

Shinichi Ide

Kenichi Kimura

Shiniti Ide

Hajime Saito

Azechi Shuuichi

Keiji Take

Hiroshi Kameda

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.

Crosslinkable rubber compositions and uses thereof

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

The invention provides an ethylene-&agr;-olefin-unconjugated polyene random copolymer rubber having hydrolyzable silyl groups in the molecule, which is crosslinkable with air-borne moisture at room temperature and is not only useful for resin modification, but also applicable as elastic sealants and adhesives, and a method for preparing the same.

Ethylene &agr;-olefin/unconjugated polyene random copolymer rubber containing hydrolyzable silyl group and process for producing the same

A coating composition comprising (A) a urethane polymer having at least one aliphatic unsaturated hydrocarbon group on a side chain in a molecule, (B) an organohydrogenpolysiloxane having at least two hydrosilyl groups in a molecule, and (C) a hydrosilylation catalyst firmly bonds to surfaces of various substrates, especially silicone rubber substrates, without a need for pre-treatment and readily forms thereon a surface protective layer having wear resistance. A silicone rubber member in which a silicone rubber substrate is coated on its surface with the inventive coating composition is endowed on the surface with wear resistance and is useful as silicone rubber key pads and silicone rubber rolls.

Coating composition and coated silicone rubber member

A liquid addition curing type silicone rubber composition comprising (A) an addition curing type organopolysiloxane component and (B) reinforcing silica fines having a specific surface area of 50-600 m,/g and surface treated with an organosilicon compound so as to bear 3-20% by weight of carbon on their surfaces prevents thickening after mixing and has an extended pot life.

Addition curing type liquid silicone rubber compositions

A silicone rubber layer is formed on a metal mandrel by curing an addition reaction curing type liquid silicone rubber composition so as to provide a resilience of 5-30% according to JIS K-6301, and an organic resin layer having a low surface energy is provided thereon, thereby yielding a low-hardness silicone rubber fixing roll, which ensures an appropriate nip width even under a low nip pressure and even when the silicone rubber layer is made thin.

Low-hardness silicone rubber fixing rolls

A mixture of a first aluminum hydroxide surface treated with a silicon-containing compound and having a mean particle size of 5-20 &mgr;m and a second aluminum hydroxide surface treated with a silicon-containing compound and having a mean particle size of 0.1-2.5 &mgr;m is blended in a silicone rubber composition comprising an organopolysiloxane, finely divided silica, and an organic peroxide. The silicone rubber composition cures into silicone rubber having sufficiently improved properties to serve as high-voltage electrical insulators, even when exposed to air polluted conditions or rigorous weather conditions.

Silicone rubber compositions for high-voltage electrical insulators

A silicone rubber composition contains (A) 100 parts by weight of an organopolysiloxane composition of the organic peroxide or addition reaction curing type, (B) 20-400 parts by weight of aluminum hydroxide, and (C) 1-20 parts by weight of an organopolysiloxane of formula (I): R.sup.1.sub.a (OX).sub.b SiO.sub.(4-a-b)/2 wherein R.sup.1 is a monovalent hydrocarbon group, at least 10 mol % of the R.sup.1 groups being phenyl, X is hydrogen or a monovalent hydrocarbon group, a and b are positive numbers satisfying the range: 1.0.ltoreq.a&lt;2.0, 1&lt;a+b.ltoreq.3, and 0.001.ltoreq.b/(a+b).ltoreq.0.8. The composition cures into a silicone rubber having improved high-voltage electrical insulating properties even under humid conditions.

A conductive organopolysiloxane composition is provided which includes (A) 100 parts by weight of an organopolysiloxane; and (B) 0.1 to 800 parts by weight of a conductive material obtained by subjecting a member selected from the group consisting of a conductive metal, a conductive metal compound, a filler surface-treated with a conductive metal and a filler surface-treated with a conductive metal compound, to surface treatment with a compound selected from the group consisting of a compound represented by the formula (1) and a compound represented by the formula (2). ##STR1## wherein R.sup.1 represents --O-- or --NH--, and R.sup.2 represents a hydrogen atom or a phenyl group. This composition is useful for the formation of a silicone rubber having a sufficient electrical conductivity and also stably retainable of electrical conductivity almost without undergoing a change in electrical conductivity even in a high-temperature environment.

Conductive organopolysiloxane composition

A silicone rubber composition is obtained by blending (A) 100 parts by weight of an organopolysiloxane composition of the addition reaction curing type with (B) about 30-400 parts by weight of aluminum hydroxide which has been surface treated with an organosilane or organosilazane substantially free of an aliphatic unsaturated group or a partial hydrolyzate thereof so that the aluminum hydroxide has 0.01-2% by weight of carbon affixed thereto. The composition maintains silicone rubber properties even though it is loaded with large amounts of aluminum hydroxide. It cures into a silicone rubber having improved high-voltage electrical insulating properties and thus suited for use as high-voltage electrical insulators.

Silicone rubber compositions for high-voltage electrical insulators and

A silicone rubber composition comprising (A) 100 parts by weight of an organopolysiloxane composition of the organic peroxide or addition curing type, (B) 1-100 parts by weight of finely divided silica, and (C) 30-500 parts by weight of aluminum hydroxide is suitable for use as a high-voltage electrical insulator. The aluminum hydroxide (C) has a water-soluble sodium ion content of up to 0.01% by weight and exhibits pH 6.5-8.0 and an electrical conductivity of up to 50 .mu.s/cm when measured as a 30 wt % water slurry and preferably has been treated to be hydrophobic. The composition cures into a silicone rubber having improved high-voltage electrical insulating properties even under rigorous conditions.

A thixotropic agent is blended in a silicone rubber composition comprising an alkenyl radical-containing organopolysiloxane, an organohydrogenpolysiloxane, an addition reaction catalyst, and filler balloons having a specific gravity of 0.01-0.40 and a mean particle size of 1-300 .mu.m. The resulting composition effectively restrains floating and separation of the filler, remains stable and is thus suitable for injection molding.

Injection molding silicone rubber compositions

A silicone rubber composition is obtained by blending (A) 100 parts by weight of an organopolysiloxane composition of the organic peroxide or addition reaction curing type, with (B) 30-400 parts by weight of aluminum hydroxide which has been surface treated so as to bear 1.0.times.10.sup.-6 to 2.0.times.10.sup.-4 mol/gram of vinyl groups. The composition does not lose rubber strength even though it is loaded with large amounts of aluminum hydroxide. It cures into a silicone rubber having satisfactory physical properties and improved high-voltage electrical insulating properties and thus suited for use as high-voltage electrical insulators.

A liquid silicone rubber base including (A) an alkenyl-containing organopolysiloxane, (B) a reinforcing silica filler, (C) a mixing assistant in the form of a silanol-containing compound, (E) an organohydrogen polysiloxane, (f) a platinum catalyst and optionally, (D) a wetting auxiliary catalyst is prepared by previously mixing 10-120 parts of component (A) with 1-35 parts of component (C) and 0-35 parts of component (D) to form a premix liquid, mixing the premix liquid with 100 parts of component (B) to form a premix power, and kneading the premix powder with the remainder of component (A). By adding a curing agent of organohydrogenpolysiloxane/platinum catalyst to the liquid silicone rubber base, there is obtained a liquid silicone rubber composition having improved fatigue endurance.

Preparation of high fatigue endurance liquid silicone rubber composition

Proposed is a method for the preparation of a monolithically integrated composite cured body consisting of a part of cured silicone rubber composition and a part of a silicone-epoxy resin composition firmly bonded together without using any primer or adhesive by first curing either one of the compositions in a metal mold and then bringing the other of the compositions into direct contact with the already cured part in the metal mold to be cured thereon. Firm bonding between the parts can be obtained when the silicone rubber composition is of the peroxide-curable or the hydrosilation-curable type and the silicone-epoxy resin composition comprises:

Composite body of silicone rubber and silicone-epoxy resin and method

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Annaka, Japan

Takeo Yoshida