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US 6,072,011 AGranted
Polycarbonate-polysiloxane block copolymers
AssigneeGeneral Electric Company
InventorJames Franklin Hoover
Life of this patent
Estimating the term…
Abstract
Block copolymers suitable as molding resins are provided having polycarbonate blocks and polysiloxane blocks of the structure ##STR1## where R.sup.1, R.sup.2, Y and m are as defined herein, and where the weight percentage of blocks of polycarbonate blocks is from 92 to 96% and the weight percentage of siloxane from blocks of polysiloxane blocks is from 4 to 8%.
Claims11
Polysiloxane-polycarbonate block copolymers, which comprise:
- (1) polycarbonate blocks with recurring units of the formula:
- ##STR7## where R.sup.3 and R.sup.4 are each independently selected from hydrogen, hydrocarbyl or halogen-substituted hydrocarbyl;
- and
- (2) interrupting polysiloxane blocks of the formula:
- ##STR8## where R.sup.1 and R.sup.2 are each independently selected from hydrogen, hydrocarbyl or halogen-substituted hydrocarbyl, D is an integer of from about 30 to about 70, and Y is selected from hydrogen, hydrocarbyl, hydrocarbyloxy or halogen;
- and
- wherein the weight percentage of said polycarbonate blocks (1) is from about 92 to about 96%, and the weight percentage of siloxane from said polysiloxane blocks (2) is from about 4 to 8%.
4 more elements
A flame retardant thermoplastic composition of high impact strength which comprises:
- (I) a polysiloxane-polycarbonate block copolymer comprising:
- (1) a polycarbonate block of the formula:
- ##STR9## where R.sup.3 and R.sup.4 are selected from hydrogen, hydrocarbyl or halogen-substituted hydrocarbyl;
- and
- (2) a polysiloxane block of the formula:
- ##STR10## where R.sup.1 and R.sup.2 are each independently selected from hydrogen, hydrocarbyl or halogen-substituted hydrocarbyl, D is from about 30 to about 70, and Y is selected from hydrogen, hydrocarbyl, hydrocarbyloxy or halogen;
- and wherein the weight percentage of said polycarbonate blocks (1) is from about 92 to about 96%, and the weight percentage of siloxane from said polysiloxane blocks (2) is from about 4 to about 8%;
- and
- (II) an effective amount of a flame retardant selected from the group consisting of a sulfonate, a halogenated compound, polytetrafluoroethylene and fumed silica.
6 more elements
A flame retardant thermoplastic composition of high impact strength consisting essentially of:
- (I) a polysiloxane-polycarbonate block copolymer comprising:
- (1) a polycarbonate block of the formula:
- ##STR11## where R.sup.3 and R.sup.4 are selected from hydrogen, hydrocarbyl or halogen-substituted hydrocarbyl;
- and
- (2) a polysiloxane block of the formula:
- ##STR12## where R.sup.1 and R.sup.2 are each independently selected from hydrogen, hydrocarbyl or halogen-substituted hydrocarbyl, D is from about 30 to about 70, and Y is selected from hydrogen, hydrocarbyl, hydrocarbyloxy or halogen;
- and wherein the weight percentage of said polycarbonate blocks (1) is from about 92 to about 96%, and the weight percentage of siloxane from said polysiloxane blocks (2) is from about 4 to about 8%;
- and
- (II) an effective amount of a flame retardant selected from the group consisting of a sulfonate, a halogenated compound, polytetrafluoroethylene and fumed silica.
6 more elements
A thermoplastic composition having high impact strength which comprises:
- (I) a polysiloxane-polycarbonate block copolymer comprising:
- (1) a polyearbonate block of the formula:
- ##STR13## where R.sup.3 and R.sup.4 are selected from hydrogen, hydrocarbyl or halogen-substituted hydrocarbyl;
- and
- (2) a polysiloxane block of the formula:
- ##STR14## where R.sup.1 and R.sup.2 are each independently selected from hydrogen, hydrocarbyl or halogen-substituted hydrocarbyl, and Y is selected from hydrogen, hydrocarbyl, hydrocarbyloxy or halogen;
- and wherein D is an integer and the combination of D and the weight percentage of said polycarbonate blocks (1) and said polysiloxane blocks (2) are selected such that the thermoplastic composition has a ductile notched izod failure at 0.degree. C. or less as tested by the ASTM D-256 impact test at a thickness of 250 millimeters.
4 more elements
Dependencies are inferred from the claim text.