This organopolysiloxane composition, when cured at room temperature by moisture in the atmosphere, provides a silicone rubber cured product having good self-adhesiveness to a magnesium alloy. The organopolysiloxane composition contains (A) an organopolysiloxane having a hydroxy group and/or a hydrolysable silyl group at both ends of the molecular chain, (B) an organic silicon compound other than (A) and (C), having at least three hydrolysable groups bonded to a silicon atom per molecule, and/or a partial hydrolysis-condensation product thereof, and (C) a silane coupling agent having a specific molecular structure having a carboxylic acid silyl ester bond. Furthermore, a novel compound, having an alkoxysilyl group and a carboxylic acid silyl ester group per molecule, can have improved adhesiveness/bonding properties with respect to a base material due to the effect of carboxylic acid after hydrolysis thereof.

This organopolysiloxane composition, when cured at room temperature by moisture in the atmosphere, provides a silicone rubber cured product having good self-adhesiveness to a magnesium alloy. The organopolysiloxane composition contains (A) an organopolysiloxane having a hydroxy group and/or a hydrolysable silyl group at both ends of the molecular chain, (B) an organic silicon compound other than (A) and (C), having at least three hydrolysable groups bonded to a silicon atom per molecule, and/or a partial hydrolysis-condensation product thereof, and (C) a silane coupling agent having a specific molecular structure having a carboxylic acid silyl ester bond. Furthermore, a novel compound, having an alkoxysilyl group and a carboxylic acid silyl ester group per molecule, can have improved adhesiveness/bonding properties with respect to a base material due to the effect of carboxylic acid after hydrolysis thereof.

This organopolysiloxane composition, when cured at room temperature by moisture in the atmosphere, provides a silicone rubber cured product having good self-adhesiveness to a magnesium alloy. The organopolysiloxane composition contains (A) an organopolysiloxane having a hydroxy group and/or a hydrolysable silyl group at both ends of the molecular chain, (B) an organic silicon compound other than (A) and (C), having at least three hydrolysable groups bonded to a silicon atom per molecule, and/or a partial hydrolysis-condensation product thereof, and (C) a silane coupling agent having a specific molecular structure having a carboxylic acid silyl ester bond. Furthermore, a novel compound, having an alkoxysilyl group and a carboxylic acid silyl ester group per molecule, can have improved adhesiveness/bonding properties with respect to a base material due to the effect of carboxylic acid after hydrolysis thereof.

A two-component type room temperature fast-curing organopolysiloxane composition which is a room temperature curing organopolysiloxane composition of a two-component and dealcohol type and which comprises, as curing agents, a first agent containing a hydrolyzable organosilane compound represented by formula (3) and/or a partially hydrolyzed condensation product thereof and a second agent containing a curing catalyst. This composition has particularly excellent fast-curing properties and deep-curing properties and provides a cured product having both high storage stability and high durability.

##STR00001##

(R.sup.6 represents an unsubstituted or substituted monovalent hydrocarbon group having 1-20 carbon atoms; R.sup.7 represents an unsubstituted or substituted alkyl group having 1-20 carbon atoms or an unsubstituted or substituted cycloalkyl group having 3-20 carbon atoms; and a is from 1 to 3.)

A two-component type room temperature fast-curing organopolysiloxane composition which is a room temperature curing organopolysiloxane composition of a two-component and dealcohol type and which comprises, as curing agents, a first agent containing a hydrolyzable organosilane compound represented by formula (3) and/or a partially hydrolyzed condensation product thereof and a second agent containing a curing catalyst. This composition has particularly excellent fast-curing properties and deep-curing properties and provides a cured product having both high storage stability and high durability.

##STR00001##

(R.sup.6 represents an unsubstituted or substituted monovalent hydrocarbon group having 1-20 carbon atoms; R.sup.7 represents an unsubstituted or substituted alkyl group having 1-20 carbon atoms or an unsubstituted or substituted cycloalkyl group having 3-20 carbon atoms; and a is from 1 to 3.)

Provided is a silicone gel composition that provides a silicone gel cured product having excellent storage stability as well as heat resistance and transparency at high temperatures, being capable of maintaining low elastic modulus, low stress, and high transparency even when used for long periods of time, particularly under conditions where only one direction of a member is exposed to high temperatures, and having resistance to cracking, peeling, and the like. The silicone gel composition comprises (A) a branched organopolysiloxane having an alkenyl group bonded to a silicon atom, (B-1) a branched organohydrogenpolysiloxane having three or more silicon atom-bonded hydrogen atoms in a molecule, and containing at least 20 mol % or more of T units and Q units of all siloxane units, (B-2) a chain organohydrogenpolysiloxane having two silicon atom-bonded hydrogen atoms in one molecule, (C) a platinum-based addition reaction catalyst, and (D) a reaction product of ceric salt.

Provided is a silicone gel composition that provides a silicone gel cured product having excellent storage stability as well as heat resistance and transparency at high temperatures, being capable of maintaining low elastic modulus, low stress, and high transparency even when used for long periods of time, particularly under conditions where only one direction of a member is exposed to high temperatures, and having resistance to cracking, peeling, and the like. The silicone gel composition comprises (A) a branched organopolysiloxane having an alkenyl group bonded to a silicon atom, (B-1) a branched organohydrogenpolysiloxane having three or more silicon atom-bonded hydrogen atoms in a molecule, and containing at least 20 mol % or more of T units and Q units of all siloxane units, (B-2) a chain organohydrogenpolysiloxane having two silicon atom-bonded hydrogen atoms in one molecule, (C) a platinum-based addition reaction catalyst, and (D) a reaction product of ceric salt.

A compound for bonded magnet that increases the mechanical strength (for example, crushing strength) of a bonded magnet is provided. The compound for bonded magnet includes a magnetic powder, an epoxy resin, a curing agent, a coupling agent, and a metal salt, and the metal salt is represented by R.sub.2M, in which R represents a saturated fatty acid group having 6 or more and 10 or less carbon atoms, while M represents at least one metal element between Ca and Ba.

A compound for bonded magnet that increases the mechanical strength (for example, crushing strength) of a bonded magnet is provided. The compound for bonded magnet includes a magnetic powder, an epoxy resin, a curing agent, a coupling agent, and a metal salt, and the metal salt is represented by R.sub.2M, in which R represents a saturated fatty acid group having 6 or more and 10 or less carbon atoms, while M represents at least one metal element between Ca and Ba.

A curable silicone adhesive composition comprising adhesion promoter is shown and described herein. The adhesion promoter is a silicon hydride material containing an aromatic based skeleton with another adhesion promoter to provide a silicone material that is curable at relatively low temperatures and shorter time and provides good adhesion to plastics and metal.