Shin-Etsu Chemical Co., Ltd.

Yasuhisa Osawa

Shinichi Sato

Takashi Matsuda

Makoto Sato

Masatoshi Arai

Noriyuki Koike

Hirofumi Kishita

Kenichi Fukuda

Yasunori Sakano

Mikio Iino

A primer composition for a fluorinated elastomer or a fluorinated gel, said primer composition comprising:

Primer composition for a fluorinated elastomer or a fluorinated gel

A curable fluoropolyether rubber composition comprising (A) a straight-chain fluoropolyether compound having at least two alkenyl groups in a molecule and a perfluoropolyether structure in the backbone, (B) an organosilicon compound having at least two hydrosilyl groups in a molecule, (C) a compound containing at least one fluorine atom and at least one benzene ring in a molecule, free of a polar group, having a melting point of at least 50&#xb0; C., in powder form, and (D) a hydrosilylation catalyst cures into a rubber product having solvent resistance, chemical resistance, improved mold release property and satisfactory compression set.

Curable fluoropolyether rubber compositions and rubber articles

A crosslinkable fluororubber composition comprising (A) a polymer of the formula: Z-(Rf-Q)&#x2014;Rf-Z wherein n is an integer of at least 1, Rf is a divalent perfluoroalkylene or perfluorooxyalkylene radical, Q is a divalent organic radical, and Z is a monovalent organic radical, having a viscosity of at least 1,000 Pa&#xb7;s at 25&#xb0; C., (B) a reinforcing filler, and (C) a peroxide crosslinking agent is effectively roll milled and experiences minimal changes of viscosity after milling. Molded parts can be produced on a mass scale.

Fluororubber compositions and articles thereof

A primer composition comprises (a) a fluoroalkylene or fluoropolyether compound having at least one alkenyl radical and at least one hydrolyzable silyl radical, (b) an organic titanic acid ester, (c) an organic tin compound, and (d) a silane compound. The primer composition is fully adherent to various substrates of metals, glass, ceramics, cement, mortar, carbon, and plastics, and is particularly suited for use with a thermosetting elastomer composition based on a polymer having at least two alkenyl radicals and a perfluoropolyether structure in its backbone.

Primer composition

A curable fluoropolyether rubber composition comprising (A) a straight-chain fluoropolyether compound having at least two alkenyl groups and a perfluoropolyether structure, (B) an organosilicon compound having at least two SiH groups, (C) a perfluoroparaffin or derivative in powder form, at least 80% by weight of which volatilizes off when held in a drier at 200&#xb0; C. for 4 hours, and which has a melting point of at least 50&#xb0; C., and (D) a hydrosilylation catalyst cures into a product that exhibits solvent resistance, chemical resistance, weather resistance, water repellency, oil repellency and heat resistance, and is improved in mold release and compression set.

A crosslinkable fluororubber composition comprising (A) a liquid perfluoro compound having alkenyl groups and a divalent perfluorolakylene or perfluoropolyether structure, (B) a reinforcing filler, (C) a surface treating agent having a fluoroalkyl or fluoropolyalkyl ether group and a silanol group, (D) an addition reactive compound having hydrosilyl groups, and (E) a hydrosilyl or peroxide crosslinker is prepared by mixing components (A) to (C) to form a liquid or paste composition, adding component (D) thereto to form a millable composition, and mixing component (E) therewith. The composition is effectively roll workable and cures into products having excellent physical properties.

Crosslinkable fluororubber compositions and method of preparation

In an injection mold comprising a cavity and a gate for feeding a molding material into the cavity, the molding material fed from the gate into the cavity is divided into two streams that flow through the cavity and then meet at a confluent point so that the molding material portions are joined together along a joint plane. Two air vent gates are spaced apart from the confluent point so as to provide a larger area of the joint plane. Articles having a good outer appearance and improved strength at the material joint can be consistently manufactured to a high precision.

Injection mold and method for manufacturing injection molded articles

A fluororubber composition comprising (A) a liquid perfluoro compound having at least two alkenyl groups and a divalent perfluorolakylene or perfluoropolyether structure, (B) a compound capable of addition reaction having at least two hydrosilyl groups, components (A) and (B) being combined and precured in the presence of an addition reaction catalyst to form a precured base, (C) a reinforcing filler, and (D) a peroxide crosslinking agent containing an isopropyl monocarbonate group has improved solvent resistance, chemical resistance, heat resistance and low-temperature properties, as well as satisfactory rubber physical properties, especially strength.

Fluororubber compositions and making method

Rubber aircraft parts are made of the cured form of a curable composition comprising a perfluoropolyether polymer having a perfluoropolyether backbone and at least one reactive group, a crosslinking agent for crosslinking the polymer, and a silica filler having an average particle size of 0.001-10 &mgr;m. By providing dramatically improved sealability at low temperatures of &minus;25 to &minus;55&deg; C., particularly during use in a dynamic state, and much improved resistance to amines and other chemicals, such rubber parts can ensure the reliable sealability of fluid line junctions in jet engines.

Rubber parts for aircraft

A liquid fluoropolyether base rubber composition comprising (A) a linear fluoropolyether compound containing at least two alkenyl groups and having a perfluoroalkyl ether structure in its backbone, (B) a silica filler having a specific surface area of at least 100 m /g and a bulk density of 100-200 g/l, (C) a curing amount of an organosilicon compound having at least two silicon-bound hydrogen atoms, and (D) a hydrosilylation catalyst is unlikely to thicken despite filler loading, is suitable for liquid injection molding and curable into products having improved mechanical properties as well as water repellency, oil repellency, solvent resistance, chemical resistance and weather resistance.

Curable fluoropolyether base rubber compositions

A crosslinkable fluororubber composition comprising (A) a perfluoro compound having at least two alkenyl groups and a divalent perfluoroalkylene or perfluoropolyether structure in the backbone or a polymer obtained by adding a compound having at least two hydrosilyl groups in the molecule to some alkenyl groups on the perfluoro compound, (B) a reinforcing filler, (C) a addition reaction crosslinking agent having a hydrosilyl group or a peroxide crosslinking agent, and (D) a surface treating agent having at least one fluoroalkyl or fluoropolyalkyl ether group and silanol groups is improved in heat resistance in the cured state by adding thereto (E) a heat resistance modifier selected from carbon black, metal oxides and metal hydroxides.

Fluororubber compositions

A crosslinkable fluororubber composition comprising (A) a polymer comprising a perfluoro compound having at least two alkenyl groups and a divalent perfluoroalkylene or perfluoropolyether structure a compound having at least two hydrosilyl groups, the hydrosilyl-bearing compound being added to some of the alkenyl groups in the perfluoro compound, (B) a reinforcing filler, and (C) a crosslinking agent having a hydrosilyl group and capable of addition reaction or a peroxide crosslinking agent, and (D) a surface treating agent having at least one fluoroalkenyl group and silanol group in the molecule, is roll millable and compression moldable. It cures into products having satisfactory solvent resistance, chemical resistance, heat resistance, and low-temperature properties.

Fluororubber compositions and method of making

A mold for producing molded fluoroelastomer parts has a mold cavity, a gate, and a runner and a sprue through which the gate communicates with an injection molding machine wherein an inorganic filler-containing crosslinkable liquid fluoroelastomer composition is injected into the mold cavity through the gate. The gate portion of the mold is surface treated with diamond-like carbon and has a cross-sectional area where it opens out into the mold cavity of 0.075-10 mm . This combination of features lowers wear at the mold gate, thereby increasing the useful life of the mold, and also improves the mold release properties.

Method for producing molded fluoroelastomer parts

A crosslinkable fluororubber composition comprising (A) a polymer comprising a perfluoro compound having at least two alkenyl groups and a divalent perfluoroalkylene or perfluoropolyether structure and a compound having at least two hydrosilyl groups, the hydrosilyl-bearing compound being added to some of the alkenyl groups in the perfluoro compound, (B) a reinforcing filler, and (C) a crosslinking agent having a hydrosilyl group and capable of addition reaction or a peroxide crosslinking agent is roll millable and compression moldable. It cures into products having satisfactory solvent resistance, chemical resistance, heat resistance, and low-temperature properties.

Proposed is a polyol-crosslinkable fluorocarbon rubber-based composition which exhibits excellent workability in milling and molding as well as excellent storage stability and is capable of giving a molded and vulcanized rubber article at a high vulcanization velocity with good mold-releasability of the molded and vulcanized rubber article from the metal mold. The rubber composition comprises, as the essential ingredients: (a) a polyol-crosslinkable fluorocarbon rubber and (b) a crosslinking agent which is, in place of a conventional polyol compound such as bisphenol A, a silylated polyol compound such as 1,1,1,3,3,3-hexafluoro-2,2-bis(4-trimethylsiloxy phenyl) propane, i.e. a silylation product of bisphenol AF.

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Gunma-ken, Japan

Yasuhisa Osawa