US 4,056,492 AGranted

Process for the production of a bodied silicone resin without the use of a catalyst

AssigneeGeneral Electric Company

InventorDuane F. Merrill

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Abstract

A process for the production of a bodied silicone resin without the use of a catalyst comprising first hydrolyzing the organohydrosilanes in a homogeneous hydrolysis medium composed of water and acetone, removing the acid/water layer, adding at least 10% by weight of water based on the silicone resin hydrolyzate and heating the resulting mixture to at least 130.degree. C and more preferably at a temperature range from 140.degree. C to 160.degree. C. After this bodying step, water constituting at least 10% by weight of the silicone resin hydrolyzate as well as water-immiscible organic solvent may be added to the silicone hydrolyzate and the resulting mixture heated at elevated temperatures so as to remove all the water and acetone. This procedure of adding water may be repeated until the silicone resin hydrolyzate has an acid content that does not exceed 5 parts per million. The silicone resin of the instant case may be prepared as 100% solids or at a concentration of 70 to 95% solids in a water-immiscible organic solvent.

Claims13

Dependent claims

A process for the production of a bodied silicone resin without the use of a catalyst comprising (a) adding a organohalosilane to a homogeneous hydrolysis mixture where there is present per part or organohalosilane from at least 1.7 to 10 parts of water and from at least 0.2 to 5 parts of acetone and from 0 to about 1 mole of an aliphatic monohydric alcohol having from 1 to 8 carbon atoms, per mole of halogen attached to the silicone of the organohalosilane to produce a silicone resin hydrolyzate (b) separating the acid/water layer from the silicone resin hydrolyzate;

(c) adding to the silicone resin hydrolyzate at least 5% by weight of water based on the silicone resin hydrolyzate;
(d) heating the silicone resin hydrolyzate gradually for a period of time of 1 to 8 hours to at least 130.degree. C;
and (e) removing the water and acetone from the silicone resin hydrolyzate to leave the silicone resin;
wherein said organohalosilane is selected from the group consisting of (1) organotrihalosilane (2) a mixture of organotrihalosilane and diorganodihalosilane, (3) a reaction product of an aliphatic monohydric alcohol having from 1 to 8 carbon atoms and a member selected from the class consisting of organotrihalosilane and a mixture of organotrihalosilane and diorganodihalosilane, which reaction product can have substituted an average of up to one alkoxy radical per halogen radical, (4) a mixture of the reaction product of (3) and a member selected from organotrihalosilane and diorganodihalosilane, and wherein the organo groups of said organohalosilane and the silicone resin are selected from the class consisting of monovalent hydrocarbon radicals, and halogenated monovalent hydrocarbon radicals.

1 more element

An encapsulating film composed of a silicone resin having a viscosity in the range of 40,000 to 100,000 centipoise which is produced by a process comprising (a) adding an organohalosilane to a homogeneous hydrolysis mixture where there is present per part of organohalosilane from at least 1.7 to 10 parts of water and from at least 0.2 to 5 parts of acetone and from 0 to about 1 mole of an aliphatic monohydric alcohol having from 1 to 8 carbon atoms per mole of halogen attached to the silicone of the organohalosilane to produce a silicone resin hydrolyzate;

(b) separating the acid/water layer from the silicone resin hydrolyzate;
(c) adding to the silicone resin hydrolyzate at least 5% by weight of water based on the silicone resin hydrolyzate;
(d) heating the silicone resin hydrolyzate gradually for a period of time of 1 to 8 hours to at least 130.degree. C;
and (e) removing the water and acetone from the silicone resin hydrolyzate to leave the silicone resin wherein organohalosilane is selected from the group consisting of (1) organotrihalosilane;
(2) a mixture of organotrihalosilane and diorganodihalosilane;
(3) a reaction product of an aliphatic monohydric alcohol having from 1 to 8 carbon atoms and a member selected from the class consisting of organotrihalosilane, and a mixture of organotrihalosilane and diorganodihalosilane, which reaction product can have substituted an average of up to one alkoxy radical per halogen radical;
(4) a mixture of the reaction product of (3) and a member selected from organotrihalosilane and diorganodihalosilane, and wherein the organo groups of said organohalosilane and the silicone resin are selected from the class consisting of monovalent hydrocarbon radicals, and halogenated monovalent hydrocarbon radicals.

4 more elements

Dependencies are inferred from the claim text.