Shin-etsu Chemical Co., Ltd.

Manabu Narumi

Toshio Shiobara

Hisashi Shimizu

Kazutoshi Tomiyoshi

Takeo Yoshida

Masaharu Takahashi

Masaya Arakawa

Kenichi Kimura

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

A liquid silicone rubber composition contains (A) an organopolysiloxane having at least two alkenyl groups, (B) a reinforcing silica filler, (C) a condensation catalyst, (D) a silanol group-containing siloxane wetter, (E) an organohydrogenpolysiloxane having at least two hydrogen atoms, and (F) a platinum catalyst. Components (C) and (D) assist in blending a large amount of the silica filler in the composition. The composition is smoothly flowing, quickly curable and suitable for injection molding.

Liquid silicone rubber compositions

To a silicone rubber composition including (A) a diorganopolysiloxane having an aliphatic unsaturated hydrocarbon group, (B) an organohydrogenpolysiloxane having at least two SiH groups in a molecule, and (C) a platinum catalyst, is added (D) an organic silicon compound of the following general formula (2): ##STR1## wherein R.sup.2, R.sup.5, and R.sup.6 are independently selected from monovalent hydrocarbon groups free of an aliphatic unsaturated bond, R.sup.3 is a monovalent hydrocarbon group, R.sup.4 is hydrogen or methyl, and n is an integer of 0 to 3. The composition has a long pot life after addition of curing components (B) and (C) and is extrusion moldable into bubble-free transparent parts. The composition is prepared by mixing component (A) with components (B) and (C) while adding component (D) thereto.

Silicone rubber compositions and method for making

Fluorine-modified thermosetting reins are available as phenolic or epoxy resins having trifluoromethyl groups and a naphthalene skeleton in a molecule. They are useful as components of resin compositions or resin modifiers and cure to products having low water pickup, low coefficient of thermal expansion, and adhesion as well as heat resistance and mechanical strength. Thermosetting resin compositions having such a thermosetting resin blended therein are useful in semiconductor element packaging.

Fluorine-modified thermosetting resin and thermosetting resin composition

A thermosetting resin composition contains (A) an imide compound having a maleimide group, (B) an epoxy resin, (C) a phenolic resin, and optionally, (D) an aromatic polymer/organopolysiloxane copolymer. Component (B) and/or (C) includes a compound containing a naphthalene ring having an allyl group and preferably, a compound containing a naphthalene ring and a double bond conjugated with an aromatic ring. The composition is easily workable and cures to products having improved heat resistance, low thermal expansion, and low water absorption.

Thermosetting resin compositions

A naphthalene derivative of the following general formula (1) having at least one allyl or propenyl group is described. ##STR1## In the formula, each G represents a hydrogen atoms or ##STR2## R.sup.1 's independently represent a hydrogen atom, an allyl group or a propenyl group provided that at least one or R.sup.1 's is an allyl group or a propenyl group, and R.sup.2 's independently represent a hydrogen atom, an unsubstituted or substituted monovalent hydrocarbon group having from 1 to 6 carbon atoms, or a halogen atom. The derivative is useful for modifying curable resins or resin compositions to provide cured products which have a low water absorption, high strength and a high glass transition temperature. The derivative has good working properties and a good heat resistance.

Allyl or propenyl group-containing naphthalene derivatives

A naphthalene of the following formula (1) having at least two allyl or propenyl groups ##STR1## wherein each G represents a hydrogen atoms or ##STR2## R.sup.1 's independently represent a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group having from 1 to 6 carbon atoms, R.sup.2 's independently represent a hydrogen atom, an allyl group or a propenyl group, R.sup.3 represents an allyl group or a propenyl group, X represents a hydrogen atom or a halogen atom, and n is an integer of from 0 to 6. The derivative is useful for modifying curable resins or resin compositions to provide cured products which have a low water absorption, high strength and a high glass transition temperature. The derivative has good working properties and a good heat resistance.

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Annaka, Japan

Manabu Narumi