Branched organopolysiloxanes and organopolysiloxanes with low alkoxy content are produced in a first reaction unit by continuous feed of organohalosilanes and alcohol to a reaction vessel surmounted by a distillation column, the vessel containing an excess of water relative to the halogen content of the organohalosilanes. A second reaction unit for removing volatiles from the product from the first reaction unit is also preferably employed.

This polysiloxane: comprises a hydrolytic condensation product of a silicon compound that contains a cyclic alkoxysiloxane represented by formula (1) ##STR00001##
(in the formula, R.sup.1 groups each independently denote a substituted or unsubstituted alkyl group having 1-3 carbon atoms, R.sup.2 groups each independently denote a substituted or unsubstituted alkyl group having 1-6 carbon atoms, and n denotes an integer between 3 and 8); has at least two hydrosilylable carbon-carbon unsaturated groups per molecule; has at least two hydrosilyl groups per molecule; and in which the inequality 0.25≤t1<1 is satisfied, where t1 denotes the molar ratio of T units having a group represented by R.sup.1 relative to all siloxane units in the hydrolytic condensation product. The polysiloxane is addition crosslinkable, and is therefore suitable as a binder component of a heat-resistant paint or the like or as a coating material.

A bissilylamino group-containing organic polysilazane compound having an average composition represented by general formula (1) below: ##STR00001##
wherein R.sup.1 is a monovalent hydrocarbon group, R.sup.2 is a divalent hydrocarbon group, R.sup.3 and R.sup.4 are a monovalent hydrocarbon group, R.sup.3 and R.sup.4 optionally bond each other to form a ring structure together with a silicon atom to which R.sup.3 and R.sup.4 are bonded and a nitrogen atom to which the silicon atom is directly bonded, R.sup.5 is a monovalent hydrocarbon group, p is 0 or 1, q is 0, 1, or 2, and a and b are numbers which satisfy 0<a≤1, 0≤b<1, and a+b=1, and having a number average molecular weight in terms of polystyrene measured by GPC of 500 to 100,000.

A bissilylamino group-containing organic polysilazane compound having an average composition represented by general formula (1) below: ##STR00001##
wherein R.sup.1 is a monovalent hydrocarbon group, R.sup.2 is a divalent hydrocarbon group, R.sup.3 and R.sup.4 are a monovalent hydrocarbon group, R.sup.3 and R.sup.4 optionally bond each other to form a ring structure together with a silicon atom to which R.sup.3 and R.sup.4 are bonded and a nitrogen atom to which the silicon atom is directly bonded, R.sup.5 is a monovalent hydrocarbon group, p is 0 or 1, q is 0, 1, or 2, and a and b are numbers which satisfy 0<a≤1, 0≤b<1, and a+b=1, and having a number average molecular weight in terms of polystyrene measured by GPC of 500 to 100,000.

A method of inverting the phase arrangement of the silicone phase and the acrylic phase in a silicone acrylic hybrid composition, the silicone acrylic hybrid composition comprising: a) a silicone acrylic hybrid pressure sensitive adhesive, and b) a solvent, wherein the phase arrangement of the silicone phase and the acrylic phase in the initial silicone acrylic hybrid composition forming a continuous external phase and a discontinuous internal phase is determined by the solvent, comprising the step of adding an activator to the silicone acrylic hybrid composition, wherein the activator a) is liquid at 20° C. and 1013 mbar, b) has a boiling point which is higher than the boiling point of the solvent and/or has a vapor pressure at 20° C. which is lower than the vapor pressure of the solvent contained in the silicone acrylic hybrid composition, and c) provides better dissolution properties for the inner phase of the initial silicone acrylic hybrid composition than the solvent contained in the silicone acrylic hybrid composition.

A method of inverting the phase arrangement of the silicone phase and the acrylic phase in a silicone acrylic hybrid composition, the silicone acrylic hybrid composition comprising: a) a silicone acrylic hybrid pressure sensitive adhesive, and b) a solvent, wherein the phase arrangement of the silicone phase and the acrylic phase in the initial silicone acrylic hybrid composition forming a continuous external phase and a discontinuous internal phase is determined by the solvent, comprising the step of adding an activator to the silicone acrylic hybrid composition, wherein the activator a) is liquid at 20° C. and 1013 mbar, b) has a boiling point which is higher than the boiling point of the solvent and/or has a vapor pressure at 20° C. which is lower than the vapor pressure of the solvent contained in the silicone acrylic hybrid composition, and c) provides better dissolution properties for the inner phase of the initial silicone acrylic hybrid composition than the solvent contained in the silicone acrylic hybrid composition.

Described is a process for producing acidified, preferably superacid-acidified, in particular trifluoromethanesulfonic acid-acidified, end-equilibrated linear α,ω-acetoxy-bearing siloxanes, wherein linear α,ω-hydroxy-bearing siloxanes, using acid, preferably superacid, particularly preferably perfluoroalkanesulfonic acid, especially preferably trifluoromethanesulfonic acid, as catalyst, are reacted with acetic anhydride and with addition of acetic acid.

Described is a process for producing acidified, preferably superacid-acidified, in particular trifluoromethanesulfonic acid-acidified, end-equilibrated linear α,ω-acetoxy-bearing siloxanes, wherein linear α,ω-hydroxy-bearing siloxanes, using acid, preferably superacid, particularly preferably perfluoroalkanesulfonic acid, especially preferably trifluoromethanesulfonic acid, as catalyst, are reacted with acetic anhydride and with addition of acetic acid.

A silsesquioxane resin, photoresist composition comprising the silsesquioxane resin and a photoacid generator, etching mask composition comprising the silsesquioxane resin, products prepared therefrom, methods of making and using same, and manufactured articles and semiconductor devices containing same. The silsesquioxane resin comprises silicon-bonded hydrogen atom T-units and T-units having a silicon-bonded group of formula —CH.sub.2CH.sub.2CH.sub.2CO.sub.2C(R.sup.1a).sub.3 or —CH(CH.sub.3)CH.sub.2CO.sub.2C(R.sup.1a).sub.3, wherein each R.sup.1a is independently an unsubstituted (C.sub.1-C.sub.2)alkyl.

A silsesquioxane resin, photoresist composition comprising the silsesquioxane resin and a photoacid generator, etching mask composition comprising the silsesquioxane resin, products prepared therefrom, methods of making and using same, and manufactured articles and semiconductor devices containing same. The silsesquioxane resin comprises silicon-bonded hydrogen atom T-units and T-units having a silicon-bonded group of formula —CH.sub.2CH.sub.2CH.sub.2CO.sub.2C(R.sup.1a).sub.3 or —CH(CH.sub.3)CH.sub.2CO.sub.2C(R.sup.1a).sub.3, wherein each R.sup.1a is independently an unsubstituted (C.sub.1-C.sub.2)alkyl.