Dow Corning Asia Limited

Dow Corning Corporation

Brian Robert Harkness

Mamoru Tachikawa

Kasumi Takei

Kasumi Takeuchi

Phillip Joseph Griffith

William Herron

Rosemary M Taylor

David J Wilson

Richard G Taylor

Ultraviolet-curable polysiloxane composition and method for the formation of cured patterns therefrom

The present invention provides a curable composition which comprises (A) a base-generating substance which generates a base when exposed to the action of ultraviolet light, (B) a siloxane polymer which has silicon-hydrogen bonds (Si--H) capable of reacting with hydroxy groups under the effect of the base to form silicon-oxygen bonds (Si--O) and hydrogen molecules (H.sub.2), and (C) an acid substance. This composition is cured by irradiation with ultraviolet light. During this ultraviolet irradiation, a mask is placed between a coating film of the composition and the radiation source, and the uncured portions of the composition are dissolved and removed so that a pattern is formed. The residual portions are then heated to produce a pattern-cured product.

Radiation-curable composition and method for manufacturing cured-product

The instant invention pertains to a curable composition comprising

Ultraviolet-curable polysiloxane composition and method for the

A process for which making silicone-filler mixtures which comprises effecting the ring-opening polymerisation of a cyclosiloxane with a phosphazene base in the presence of a filler and of water, preferably from 0.5 mil to 10 mols of water per mol of phosphazene base. The filler is preferably selected from silica, alumina, titanium dioxide, carbon black and calcium carbonate, present in an amount of from 1 to 200 parts by weight per 100 parts by weight of cyclosiloxane. An agent or conditions which inhibit catalyst activity may initially be present (e.g. carbon dioxide or excess water), and polymerisation may be initiated by reducing the effect of the inhibiting agent or conditions (e.g. by heating). Silicon-elastomers produced by curing such silicone polymer-filler mixtures are also claimed.

Polymerization of cyclosiloxanes in the presence of fillers

A method for the preparation of hydrophobic fumed silicas which are useful, for example, as reinforcing fillers in rubber compositions. The method comprises two steps, where in the first step an aqueous suspension of fumed silica is contacted with an organosilicon compound in the presence of a catalytic amount of an acid to effect hydrophobing of the fumed silica. In the preferred method the first step is conducted in the presence of a water miscible organic solvent which facilitates hydrophobing of the fumed silica with the organosilicon compound and the fumed silica has a BET surface area greater than 50 m.sup.2 /g. In the second step the aqueous suspension of the fumed silica is contacted with a water-immiscible organic solvent at a solvent to silica weight ratio greater than 0.1:1 to effect separation of the hydrophobic fumed silica from the aqueous phase. In a preferred process the hydrophobic fumed silica has a surface area within a range of about 100 m.sup.2 /g to 750 m.sup.2 /g.

Method for preparing hydrophobic fumed silica

A method for the preparation of hydrophobic precipitated silicas which are useful, for example, as reinforcing fillers in rubber compositions. The method comprises two steps, where in the first step an aqueous suspension of precipitated silica is contacted with an organosilicon compound in the presence of a catalytic amount of an acid to effect hydrophobing of the precipitated silica. In the second step the aqueous suspension of the hydrophobic precipitated silica is contacted with a water-immiscible organic solvent at a solvent to silica weight ratio greater than 5:1 to effect separation of the hydrophobic precipitated silica from the aqueous phase.

Method of preparing hydrophobic precipitated silica

Curable compositions comprising a substance that produces a base when exposed to radiation and a polymer molecule that contains silicon-hydrogen bonds which react with hydroxyl groups under the action of the base to form silicon-oxygen bonds (Si--O) and hydrogen molecules. These compositions cure when exposed to radiation. A pattern can be formed by placing a mask between a coating of the composition and the radiation source during this exposure episode and thereafter dissolving the uncured composition. The compositions have little weight loss during their cure, they can be cured by low intensity radiation, and they yield heat-resistant cured products.

Radiation curable sompositions

Curable siloxane polymer composition and method of curing

This invention pertains to a curable composition comprising a N-substituted 4-(o-nitrophenyl)dihydropyridine (a compound that generates base under the action of ultraviolet radiation) and a silanol-containing polymer that condenses under the action of the base generated to form a siloxane bond. The compositions of the instant invention cure by exposure to ultraviolet radiation. Cured patterns may be formed from the curable composition by interposing a mask between a film of the said composition and the radiation source during UV exposure, then dissolving and removing the uncured composition to form a pattern, and thereafter heating the residual material. The compositions can be cured by low-strength ultraviolet radiation and produce a highly heat-resistant cured product.

Ultraviolet-curable composition and method for patterning the cured

The present invention pertains to a curable composition which comprises a) a N-substituted 4-(o-nitrophenyl)dihydropyridine which constitutes a base-generating substance that is caused to generate a base by the action of ultraviolet light, and (b) a silicone polymer (R.sub.2 SiO.sub.2/2)(RSiO.sub.3/2) containing silicon-hydrogen bonds (Si--H) which are capable of reacting with hydroxy groups to form silicon-oxygen bonds (Si--O) and hydrogen molecules (H.sub.2) under the effect of the base. This composition is cured by irradiation with ultraviolet light. Patterns are formed by placing a mask between a coating film of the composition and the ultraviolet light source during the irradiation with ultraviolet light, and then dissolving and removing the uncured portions of the composition following said irradiation.

Ultraviolet-curable composition and method for forming cured-product

Radiation curable compositions

The introduction of a highly spin-coatable silicone resin that does not produce large amounts of volatiles during its cure, and that is a precursor to highly heat-resistant, optically transparent cured products that exhibit an excellent hardness. The silicone resin comprises a silicone polymer of the general formula:

Thermosetting silicone resins

There is disclosed a diphenylsiloxane oligomer functionalized at both terminals and methods for the preparation thereof, said oligomer having the following general formula

Diphenylsiloxane oligomers functionalized at both terminals and methods

There is disclosed a diphenylsiloxane oligomer functionalized at both terminals, and methods for the preparation thereof, said oligomer having the following general formula G-(OSi(Ph).sub.2).sub.m O--G wherein Ph denotes a phenyl radical, m is 3 to 50 and G is has a formula independently selected from the group consisting of ##STR1## in which R.sup.1 is independently selected from the group consisting of hydrogen and a monovalent hydrocarbon group having 2 to 8 carbon atoms, said monovalent hydrocarbon group excluding phenyl, tolyl, xylyl, and ethylphenyl radicals, R is independently selected from the group consisting of R.sup.1, methyl radical and phenyl radical, Q is a divalent hydrocarbon group and n is an integer having a value of 1 to 3.

Growing community of inventors

Cowbridge, United Kingdom

Brian Robert Harkness