Method for imparting fire retardancy to organic resins
AssigneeDow Corning Corporation
InventorsDavid J. Romenesko, Robert R. Buch
Life of this patent
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Abstract
A free-flowing silicone polymer powder, having an average particle size of 1 to 1000 microns and prepared by mixing a polydiorganosiloxane with a silica filler, is uniformly dispersed in an organic resin using conventional equipment, such as a single screw or, preferably, a twin screw extruder. When employed at a concentration of about 0.5 to 25 parts by weight of powder per 100 parts by weight of resin, a significant improvement in the burn character of the modified resin is obtained such that the rate of heat release, generation of smoke and evolution of toxic carbon monoxide gas is significantly reduced relative to the unmodified resin.
Claims34
A method for imparting fire retardancy to an organic resin selected from the group consisting of organic thermoplastic resins and organic thermoset resins, said method comprising thoroughly dispersing a silicone polymer powder in said resin to form a modified resin composition, said silicone polymer powder having an average particle size of 1 to 1000 microns and consisting essentially of
- (i) 100 parts by weight of a polydiorganosiloxane polymer, and
- (ii) from 10 to 150 parts by weight of a filler selected from the group consisting of silica and treated silica, said powder optionally containing up to 15 parts by weight of an alkoxysilane adhesion promoter for each 100 parts by weight of said silicone polymer powder.
A modified resin composition consisting essentially of:
- (A) 100 parts by weight of an organic resin selected from the group consisting of organic thermoplastic resins and organic thermoset resins;
- and
- (B) from 0.5 to 25 parts by weight of a silicone polymer powder uniformly dispersed in said resin (A), said silicone polymer powder having an average particle size of 1 to 1000 microns and consisting essentially of
- (i) 100 parts by weight of a polydiorganosiloxane polymer, and
- (ii) from 10 to 150 parts by weight of a filler selected from the group consisting of silica and treated silica, said powder optionally containing up to 15 parts by weight of an alkoxysilane adhesion promoter for each 100 parts by weight of said silicone polymer powder,
- said modified composition, when burned, having a reduced rate of combustion and a reduced evolution of carbon monoxide and smoke relative to the unmodified organic resin.
A method for imparting fire retardancy to an inherently combustible organic resin selected from the group consisting of organic thermoplastic resins and organic thermoset resins, said method comprising thoroughly dispersing an inorganic silicone polymer powder in said resin to form a modified resin composition, said inorganic silicone polymer powder having an average particle size of 1 to 1000 microns and consisting essentially of
- (i) 100 parts by weight of a polydiorganosiloxane polymer, and
- (ii) from 10 to 150 parts by weight of a filler selected from the group consisting of silica and treated silica, said powder optionally containing up to 15 parts by weight of an alkoxysilane adhesion promoter for each 100 parts by weight of said silicone polymer powder.
A modified resin composition consisting essentially of:
- (A) 100 parts by weight of an inherently combustible organic resin selected from the group consisting of organic thermoplastic resins and organic thermoset resins;
- and
- (B) from 0.5 to 25 parts by weight of an inorganic silicone polymer powder uniformly dispersed in said resin (A), said inorganic silicone polymer powder having an average particle size of 1 to 1000 microns and consisting essentially of
- (i) 100 parts by weight of a polydiorganosiloxane polymer, and
- (ii) from 10 to 150 parts by weight of a filler selected from the group consisting of silica and treated silica, said powder optionally containing up to 15 parts by weight of an alkoxysilane adhesion promoter for each 100 parts by weight of said silicone polymer powder, said modified composition, when burned, having a reduced rate of combustion and a reduced evolution of carbon monoxide and smoke relative to the unmodified organic resin.
Dependencies are inferred from the claim text.