Polycarbonate mixtures in optical applications

Claim 1

An article for an optical application comprising a) about 0.1 to 99.9 wt. % of a thermoplastic aromatic polycarbonate resin having a weight average molecular weight of at least 10,000 containing difunctional carbonate structural units corresponding to (Ia): ##STR17## wherein R 1 and R 2 independently represent hydrogen, halogen, C 1 -C 8 alkyl, C 5 -C 6 cycloalkyl, C 6 -C 10 aryl or C 7 -C 12 aralkyl; m represents 4 or 5; R 3 and R 4 , which are selected individually for each X, independently represent hydrogen or C 1 -C 6 -alkyl; and X represents a carbon atom; provided that R 3 and R 4 both represent alkyl on at least one X atom; in amounts of from 100 to 2 mole %, relative to the total molar amount of the difunctional carbonate structural units, and a complementary amount to 100 mole % of other difunctional carbonate structural units (VIIa): ##STR18## wherein --Z--represents an aromatic radical having from 6 to 30 carbons atoms; and b) from 99.9 to 0.1 wt. % of at least one thermoplastic polycarbonate other than component (a) which is characterized in that said other polycarbonate contains only difunctional carbonate structural units corresponding to (VIIa), and optionally, c) conventional additives for optical applications, wherein the sum of the wt. % of a) and b) is 100 mole %, and wherein the molar ratio of structural units (Ia) to structural units (VIIa) is from 0.1 mole % (Ia) to 55 mole % (Ia) and from 65 mole % (Ia) to 99.9 mole % (Ia), relative to the total molar amount of 100 mole % of structural units (Ia)+(VIIa) in the mixtures consisting of polycarbonate components a)+b).

Claim 7

A method for preparing an article for an optical application comprising molding a molding composition which comprises a) about 0.1 to 99.9 wt. % of a thermoplastic, aromatic polycarbonate resin having a weight average molecular weight of at least 10,000 containing difunctional carbonate structural units corresponding to (Ia): ##STR19## wherein R 1 and R 2 independently represent hydrogen, halogen, C 1 -C 8 alkyl, C 5 -C 6 cycloalkyl, C 6 -C 10 aryl or C 7 -C 12 aralkyl; m represents 4 or 5; R 3 and R 4 , which are selected individually for each X, independently represent hydrogen or C 1 -C 6 alkyl; and X represents a carbon atom; provided that R 3 and r 4 both represent alkyl on at least one X atom; in amounts of from 100 to 2 mole %, relative to the total molar amount of the difunctional carbonate structural units, and a complementary amount to 100 mole % of other difunctional carbonate structural units (VIIa): ##STR20## wherein --Z--represents an aromatic radical having from 6 to 30 carbon atoms; and b) from 99.9 to 0.1 wt. % of at least one thermoplastic polycarbonate other than component (a) which is characterized in that said other polycarbonate contains only difunctional carbonate structural units corresponding to (VIIa), and optionally, c) conventional additives for optical applications, wherein the sum of the wt. % of a) and b) is 100 mole %, and wherein the molar ratio of structural units (Ia) to structural units (VIIa) is from 0.1 mole % (Ia) to 55 mole % (Ia) and from 65 mole % (Ia) to 99.9 mole % (Ia), relative to the total molar amount of 100 mole % of structural units (Ia)+(VIIa) in the mixtures consisting of polycarbonate components a)+b).

Claim 8

A method for preparing an article for an optical application comprising molding a molding composition which comprises a) about 0.1 to 99.9 wt. % of a thermoplastic, aromatic polycarbonate resin having a weight average molecular weight of at least 10,000 containing difunctional carbonate structural units corresponding to (Ia): ##STR19## wherein R 1 and R 2 independently represent hydrogen, halogen, C 1 -C 8 alkyl, C 5 -C 6 cycloalkyl, C 6 -C 10 aryl or C 7 -C 12 aralkyl; m represents 4 or 5; R 3 and R 4 , which are selected individually for each X, independently represent hydrogen or C 1 -C 6 alkyl; and X represents a carbon atom; provided that R 3 and r 4 both represent alkyl on at least one X atom; in amounts of from 100 to 2 mole %, relative to the total molar amount of the difunctional carbonate structural units, and a complementary amount to 100 mole % of other difunctional carbonate structural units (VIIa): ##STR20## wherein --Z--represents an aromatic radical having from 6 to 30 carbon atoms; and b) from 99.9 to 0.1 wt. % of at least one thermoplastic polycarbonate other than component (a) which is characterized in that said other polycarbonate contains only difunctional carbonate structural units corresponding to (VIIa), and optionally, c) conventional additives for optical applications, wherein the sum of the wt. % of a) and b) is 100 mole %, and wherein the molar ratio of structural units (Ia) to structural units (VIIa) is from 0.1 mole % (Ia) to 55 mole % (Ia) and from 65 mole % (Ia) to 99.9 mole % (Ia), relative to the total molar amount of 100 mole % of structural units (Ia)+(VIIa) in the mixtures consisting of polycarbonate components a)+b).