Abstract: [Object] To provide a coating composition excellent in coatability and free from viscosity increase caused by degradation over time, and also to provide a hardened film-formation method employing that. [Means] The present invention provides a coating composition comprising: a siloxane resin having silanol groups or alkoxysilyl groups, and a polyol having hydroxyl groups at both ends of a straight 2 to 5 carbon atom hydrocarbon chain. This coating composition enables to form a hardened film of high transparency, of high insulation and of low dielectricity.

Abstract: A positive photosensitive siloxane composition comprising at least three types of following polysiloxanes (A), (B) and (C) obtained by hydrolyzing and condensing a silane compound represented by general formula (1) R1nSi (OR2)4-n, a diazonaphthoquinone derivative, and a solvent: a polysiloxane (A) such that if pre-baked the film thereof will be soluble in a 5 weight % TMAH aqueous solution and the solution rate of said film will be 1,000 ?/sec or less; a polysiloxane (B) such that if pre-baked the solution rate of the film thereof will be 4,000 ?/sec or more relative to a 2.38 weight % TMAH aqueous solution; and a polysiloxane (C) such that if pre-baked the solution rate of the film thereof will be between 200 and 3,000 ?/sec relative to a 2.38 weight % TMAH aqueous solution.

Abstract: A positive photosensitive siloxane composition containing: a polysiloxane (Ia), which is obtained by hydrolyzing and condensing the silane compound represented by RSi(OR1)3 in general formula (1) and the silane compound represented by Si(OR1)4 in general formula (2) in the presence of a basic catalyst, and a pre-baked film of which has a dissolution rate of 1,000 ?/second or less in a 5 wt % TMAH aqueous solution; a polysiloxane (Ib), which is obtained by hydrolyzing and condensing at least the silane compound represented by general formula (1) in the presence of an acid or basic catalyst, and a pre-baked film of which has a dissolution rate of 100 ?/second or more in a 2.38 wt % TMAH aqueous solution; and a diazonaphthoquinone derivative and solvent.

Abstract: [Object] To provide a coating composition excellent in coatability and free from viscosity increase caused by degradation over time, and also to provide a hardened film-formation method employing that. [Means] The present invention provides a coating composition comprising: a siloxane resin having silanol groups or alkoxysilyl groups, and a polyol having hydroxyl groups at both ends of a straight 2 to 5 carbon atom hydrocarbon chain. This coating composition enables to form a hardened film of high transparency, of high insulation and of low dielectricity.

Abstract: A positive photosensitive siloxane composition containing: a polysiloxane (Ia), which is obtained by hydrolyzing and condensing the silane compound represented by RSi(OR1)3 in general formula (1) and the silane compound represented by Si(OR1)4 in general formula (2) in the presence of a basic catalyst, and a pre-baked film of which has a dissolution rate of 1,000 ?/second or less in a 5 wt % TMAH aqueous solution; a polysiloxane (Ib), which is obtained by hydrolyzing and condensing at least the silane compound represented by general formula (1) in the presence of an acid or basic catalyst, and a pre-baked film of which has a dissolution rate of 100 ?/second or more in a 2.38 wt % TMAH aqueous solution; and a diazonaphthoquinone derivative and solvent.

Abstract: A composition comprising a silicon-containing copolymer having a number-average molecular weight of 500 to 1,000,000, having SiO bond in the polymer and containing at least the structural units represented by the following general formulae (I) and (II) and, if necessary, one or more of the structural units represented by the following general formulae (III) to (VII) and a cross-linking agent is reacted at ?20 to 100° C. for 1 to 3 hours. The resultant reaction composition is coated on a substrate and cured by heating to a temperature of 150° C. or above, for example, 250° C. to obtain a cured product of a silicon-containing copolymer which has a high heat resistance, a high light transmission, a low relative dielectric constant and a high chemical resistance and which has a strong mechanical strength and a good flexibility.

Abstract: An object of the present invention is to provide a composition for formation of etching stopper layer, which can simultaneously realize dry etching selectivity and low permittivity, and a production process of a semiconductor device using the same. This object can be attained by a composition for formation of etching stopper layer, comprising a silicon-containing polymer, the silicon-containing polymer contained in the composition comprising a disilylbenzene structure, and a production process of a semiconductor device comprising forming an etching stopper layer using the composition.

Abstract: A silicon-containing copolymer which comprises units represented by the general formulae (I) and (II) as essential units and ones represented by the general formulae (III) to (VII) as optional units and has a number average molecular weight of 500 to 1,000,000, —(—R1R2Si—A —)p—??(I) —(—R3R4Si—R7—SiR5R6—)q—??(II) —(—R8Si—A—)r—??(III) —(—R9(H)Si—A—)s—??(IV) —(—R1R2Si—NH—R10—NH—)t—??(V) —(—R8Si—NH—R10—NH—)u—??(VI) —(—R9(H)Si—NH—R10—NH—)w—??(VII) wherein A is NH or oxygen, the proportions of these satisfying the relationship 0.01?Si—O/(Si—N+Si—O)?0.99.

Abstract: A composition comprising a silicon-containing copolymer having a number-average molecular weight of 500 to 1,000,000, having SiO bond in the polymer and containing at least the structural units represented by the following general formulae (I) and (II) and, if necessary, one or more of the structural units represented by the following general formulae (III) to (VII) and a cross-linking agent is reacted at ?20 to 100° C. for 1 to 3 hours. The resultant reaction composition is coated on a substrate and cured by heating to a temperature of 150° C. or above, for example, 250° C. to obtain a cured product of a silicon-containing copolymer which has a high heat resistance, a high light transmission, a low relative dielectric constant and a high chemical resistance and which has a strong mechanical strength and a good flexibility.

Abstract: A silicon-containing copolymer which comprises units represented by the general formulae (I) and (II) as essential units and ones represented by the general formulae (III) to (VII) as optional units and has a number average molecular weight of 500 to 1,000,000,

Abstract: A method for forming dense ceramics, particularly a ceramic coating by a low temperature treatment is provided. The method for forming ceramics according to the invention is characterized in that a polysilazane having a number-average molecular weight of 100 to 50,000 or a modified polysilazane thereof is subjected to a heat treatment, then exposed to an atmosphere containing water vapor or immersed in distilled water containing a catalyst, or both, or is brought into contact with Pd.sup.2+ ions and water, the polysilazane having a skeleton comprising the unit represented by the following general formula (I): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a group other than the above and having a carbon atom directly attached to the silicon atom, an alkylsilyl group, an alkylamino group and an alkoxy group; with the proviso that at least one of R.sup.1, R.sup.2 and R.sup.3 is a hydrogen atom.

Abstract: A method for forming dense ceramics, particularly a ceramic coating by a low temperature treatment is provided. The method for forming ceramics according to the invention is characterized in that a polysilazane having a number-average molecular weight of 100 to 50,000 or a modified polysilazane thereof is subjected to a heat treatment, then exposed to an atmosphere containing water vapor or immersed in distilled water containing a catalyst, or both, or is brought into contact with Pd.sup.2+ ions and water, the polysilazane having a skeleton comprising the unit represented by the following general formula (I): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a group other than the above and having a carbon atom directly attached to the silicon atom, an alkylsilyl group, an alkylamino group and an alkoxy group; with the proviso that at least one of R.sub.1, R.sup.2 and R.sup.3 is a hydrogen atom.

Abstract: A silicon-containing copolymer is disclosed which has a number average molecular weight of 500-100,000 and which contains the following structural units (I)-(III): ##STR1## wherein R.sup.1, R.sup.2, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 each represent an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkylamino group or an alkylsilyl group and and R.sup.3 and R.sup.8 each represent a divalent aromatic group. The copolymer is produced by reacting an organodihalosilane, a disilyl compound, a diamine and ammonia with each other.

Abstract: A four-wheel drive vehicle control system has a differential mode control device which operates in at least a first mode, in which differential action of a differential is variably restricted between an unlocked state and a locked state according to driving conditions, and a second mode, in which the differential is forcibly locked. The first and second modes are manually selected by the driver.