Abstract: A RTV organopolysiloxane composition comprising (A) an organopolysiloxane containing at least two Si—OH or organoxy radicals and having a viscosity of at least 500 mPa-s at 25° C., (B) an organosilane containing at least two organoxy radicals, (C) an organotin catalyst, and (D) an Si—OH radical-containing organopolysiloxane having a viscosity of up to 300 mPa-s at 25° C. It has shelf stability and discoloration resistance in the uncured state and exhibits rubber elasticity and adhesion in the cured state.

Abstract: A RTV organopolysiloxane composition comprising (A) an organopolysiloxane containing at least two Si—OH or organoxy radicals and having a viscosity of at least 500 mPa-s at 25° C., (B) an organosilane containing at least two organoxy radicals, (C) an organotin catalyst, and (D) an Si—OH radical-containing organopolysiloxane having a viscosity of up to 300 mPa-s at 25° C. It has shelf stability and discoloration resistance in the uncured state and exhibits rubber elasticity and adhesion in the cured state.

Abstract: In an epoxy resin composition comprising an epoxy resin, a curing agent, and at least 70% by weight of an inorganic filler, at least one of the epoxy resin and the curing agent has such a molecular weight distribution as to provide an average dispersity Mw/Mn of less than 1.6, a two-nucleus compound content of less than 8% by weight and a seven- and more-nucleus compound content of less than 32% by weight. When the composition is cured at 180.degree. C. for 90 seconds into a primary product having Tg1 and the primary product postcured at 180.degree. C. for 5 hours into a secondary product having Tg2, the relationship: (Tg2-Tg1)/Tg2<0.1 is satisfied. The composition is fast-curing and effectively moldable and cures into a reliable product without a need for postcure.

Abstract: A novel quaternary phosphorus compound is a salt between tetraphenyl borate and a phosphonium having an aromatic group attached to a phosphorus atom through an oxygen atom. It is blended with an epoxy resin as a curing catalyst to form an epoxy resin composition which flows smoothly and quickly cures into a product having improved moisture resistance and adhesion.

Abstract: Novel fluorine-modified acid anhydrides of formula (1) are useful curing agents typically in epoxy resin compositions for encapsulating semiconductor devices. ##STR1## R.sup.1 is a hydrogen atom, substituted or unsubstituted monovalent hydrocarbon group, hydroxyl group, alkoxy group or alkenyloxy group. Rf is a divalent perfluoroalkylene or perfluoropolyether group of the general formula (2): ##STR2## wherein l is an integer of 0 to 8, k and m are integers of 0 to 15, j and n are 0 or 1, with the proviso that j, k, l, m and n are not equal to 0 at the same time.

Abstract: An epoxy resin composition comprising (i) an epoxy resin, (ii) a phenolic curing agent, (iii) an organophosphorous curing agent, (iv) alumina, and (v) a separating means for separating the organophosphorous curing agent and the alumina, which may be a coating over the surfaces of the organophosphorous curing agent.

Abstract: Novel organic silicon compounds are based on a benzene ring having two epoxy radicals and an alkoxysilane radical. They are useful as resin modifiers, adhesive aids for epoxy resins, and silane coupling agents. Inorganic fillers such as silica surface treated with the compounds are useful in encapsulating resin compositions.

Abstract: A composition comprising (A) an epoxy resin having at least two epoxy groups in a molecule, (B) a silicone-modified epoxy resin, (C) an imidazole curing agent having a solubility of up to 0.1% by weight in epoxy resin (A) at 25.degree. C., and (D) fused silica having a mean particle size of up to 10 .mu.m and adjusted to a viscosity of up to about 4,000 poise at 25.degree. C. satisfies the requirements for flip chip encapsulation since the composition has improved shelf stability and filling ability and cures into products having improved moisture resistance. Semiconductor devices encapsulated with cured products of the composition remain reliable because of moisture resistance.

Abstract: A curable polyimide resin is blended with (a) an organic silicon compound having a functional group selected from an epoxy group and an amino group or (b) a copolymer of an aromatic polymer and an organic silicon compound. The resulting polyimide resin composition can be cured without inducing a crack. It is suitable for the encapsulation of semiconductor devices as well as for molding and powder coating.

Abstract: In a light transmissive epoxy resin composition comprising (A) an epoxy resin and (B) a curing agent are blended (C) an organic phosphorus anti-discoloring agent and (D) silica-titania glass beads surface treated with an organic silicon compound. The composition restrains coloring in composition form and discoloration in cured form while curing into clear low stressed products having high light transmittance. Optical semiconductor devices encapsulated with the cured epoxy resin composition are reliable.

Abstract: High transparency silica-titania glass beads are characterized by a linear transmittance of at least 70% as measured at a wavelength of 900 nm to 600 nm by a specific measurement method. Such beads are prepared by hydrolyzing and polycondensing a silicon alkoxide and a titanium alkoxide to form a silica-titania sol, converting the sol into a dry gel, and then grinding the gel followed by heating or heating the gel followed by grinding. A light transmisson epoxy resin composition comprising a curable epoxy resin, a curing agent, and the high tranparency silica-titania glass beads has crack resistance and high transparency in cured state. It is useful in encapsulating optical semiconductor devices.

Abstract: An epoxy resin composition comprising (A) a specific epoxy resin, (B) a phenolic resin having at least one naphthalene ring in a molecule, and (C) an inorganic filler has improved flow and cures into products having a low coefficient of expansion, high Tg, and low moisture absorption. The composition is suitable for encapsulating semiconductor devices.

Abstract: A semiconductor encapsulating epoxy resin composition comprising an epoxy resin, a curing agent, and an inorganic filler is improved in melt flow and moldability when the filler comprises spherical silica having a mean particle size of 5 to 35 .mu.m and a specific surface area of up to 1.4 m.sup.2 /g. A mixture of (A) spherical silica having a mean particle size of 0.1 to 2 .mu.m, and (C) ground silica having a mean particle size of 2 to 15 .mu.m is also useful as the filler. A cured product thereof has a low coefficient of expansion and improved crack resistance upon soldering after moisture absorption.

Abstract: An epoxy resin composition which comprises a curable epoxy resin, a curing agent, an inorganic filler, and at least one copolymer selected from copolymers obtained by an addition reaction between aromatic polymers containing one or more epoxy groups and one or more alkenyl groups and the specific organopolysiloxanes; copolymers obtained by an addition reaction between aromatic polymers containing one or more epoxy groups and the specific amino group-containing organopolysiloxanes.

Abstract: A curable epoxy resin is blended with (a) an alkenyl group-containing epoxidized novolak resin/organopolysiloxane copolymer and (b) a polyimide resin in addition to a curing agent and an inorganic filler. The resulting epoxy resin composition can be cured both under moisture-free conditions and even under moist conditions without inducing a crack. It is suitable for the encapsulation of semiconductor devices as well as for molding and powder coating.

Abstract: The invention discloses a novel class of organosilane compounds containing 1 to 3 alkenyloxy groups directly bonded to the silicon atom and a 3,4-epoxycyclohexyl-substituted alkyl group bonded to the silicon atom. The compound is prepared by the reaction of 1-vinyl-3,4-epoxycyclohexane and a hydrogen alkenyloxy silane and useful as a coupling agent or an adhesion-improving agent.

Abstract: An epoxy resin composition which comprises a curable epoxy resin, a curing agent, an inorganic filler, and at least one copolymer selected from copolymers obtained by an addition reaction between aromatic polymers containing one or more epoxy groups and one or more alkenyl groups and the specific organopolysiloxanes; copolymers obtained by an addition reaction between aromatic polymers containing one or more epoxy groups and the specific amino group-containing organopolysiloxanes.

Abstract: Fine spherical particles of cured silicone elastomer can be prepared by spray-drying an aqueous emulsion of a curable organopolysiloxane composition having a particle diameter not exceeding 20 .mu.m. The organopolysiloxane composition comprises preferably an organopolysiloxane having silicon-bonded vinyl groups, an organohydrogenpolysiloxane having silicon-bonded hydrogen atoms and a platinum catalyst so that curing of the composition may take place in the emulsion before spray-drying or in the course of spray-drying by the addition reaction between the silicon-bonded vinyl groups and the silicon-bonded hydrogen atoms.

Abstract: An epoxy resin-based composition suitable for encapsulation of semiconductor devices is proposed. The resin composition is capable of giving a cured resin encapsulation highly resistant against crack formation by virtue of the unique ingredient therein, in addition to the thermally curable epoxy resin and an inorganic filler, which is a combination of an organopolysiloxane having a hydrocarbon group substituted by certain functional groups, e.g. glycidyl, amino, mercapto and the like, and a block copolymer composed of the segments of a polymeric aromatic moiety and segments of an organopolysiloxane moiety.

Abstract: The room temperature-curable (RTV) organopolysiloxane composition of the invention comprises, in addition to the conventional components of a diorganopolysiloxane terminated at both molecular chain ends each with a silanolic hydroxy group, a hydrolyzable organosilicon compound having two or more hydrolyzable groups in a molecule and a filler, an organosilicon-modified polyoxyalkylene compound, of which the organosilicon-containing terminal groups have at least one hydrolyzable group so as to pertain to the crosslinking reaction in its part. By virtue of this unique additive component, the composition is quite free from the disadvantage of sagging when the composition is applied to building works and the like and still retains excellent adhesive properties to the substrate surface in contrast to the difficulty in the conventional RTV compositions in which reducing of the phenomenon of sagging and retention of the strong adhesive strength are hardly compatible.