SCRATCH RESISTANT POLYCARBONATE COMPOSITIONS
A thermoplastic composition having improved scratch resistance comprising in combination from 20 to 80 wt. % of a polycarbonate homopolymer or copolymer comprising repeat carbonate units having the following structure: wherein R 1 and R 2 are independently at each occurrence a C 1 -C 6 alkyl, n is an integer having a value of 0 to 4, p is an integer having a value of 1 to 4, and T is selected from the group consisting of C 5 -C 10 cycloalkanes attached to the aryl groups at one or two carbons, C 1 -C 5 alkyl groups, C 6 -C 13 aryl groups, and C 7 -C 13 aryl alkyl groups; from 20 to 80 wt. % of a poly(alkyl(meth)acrylate), wherein the alkyl group is straight or branched-chain, and has 1 or 2 carbons atoms is disclosed.
1 . A thermoplastic composition comprising in combination
from 20 to 80 wt. % of a polycarbonate homopolymer or copolymer comprising repeat carbonate units having the following structure (17):
wherein R 1 and R 2 are independently at each occurrence a C 1 -C 6 alkyl, n is an integer having a value of 0 to 4, p is an integer having a value of 1 to 4, and T is selected from the group consisting of C 5 -C 10 cycloalkanes attached to the aryl groups at one or two carbons, C 1 -C 5 alkyl groups, C 6 -C 13 aryl groups, and C 7 -C 13 aryl alkyl groups;
from 20 to 80 wt. % of a poly(alkyl(meth)acrylate), wherein the alkyl group has 1 or 2 carbons atoms.
2 . The thermoplastic composition of claim 1 , wherein the repeat carbonate units of formula (17) have the following structure:
wherein R 1 and R 2 are independently selected from the group consisting of C 1 -C 6 alkyl; X represents CH 2 ; m is an integer from 4 to 9; n is an integer from 1 to 4; and p is an integer from 1 to 4, with the proviso that at least one of R 1 or R 2 is in the 3 or 3′ position.
3 . The thermoplastic composition of claim 2 , wherein the dialkyl bisphenol polycarbonate units of the copolymer have the structure
4 . The thermoplastic composition of claim 1 , further comprising an impact modifier wherein the impact modifier is ABS, MBS, ASA, polycarbonate-polysiloxane copolymer, or a combination of two or more of the foregoing impact modifiers.
5 . The thermoplastic composition of claim 1 , further comprising a flow promoter comprising a low molecular weight hydrocarbon resin derived from petroleum C 5 to C 9 feedstock
6 . The thermoplastic composition of claim 1 , wherein the poly(alkyl(meth)acrylate) is PMMA.
7 . The thermoplastic composition of claim 4 , wherein the impact modifier is ABS.
8 . The thermoplastic composition of claim 4 , wherein the impact modifier is polycarbonate-polysiloxane copolymer.
9 . The thermoplastic composition of claim 4 , wherein the impact modifier is ABS and polycarbonate-polysiloxane copolymer.
10 . The thermoplastic composition of claim 1 , further comprising a polycarbonate homopolymer or copolymer different from the polycarbonate having repeat carbonate units having the structure (17).
11 . The thermoplastic composition of claim 1 , further comprising a flame retardant.
12 . An article comprising the thermoplastic composition of claim 1 .
13 . The article of claim 12 , wherein the article has a scratch resistance of less than 17 when measured according to ISO 1518.
14 . The article of claim 13 , wherein the article has a scratch resistance of less than 12 when measured according to ISO 1518.
15 . A thermoplastic composition comprising in combination
from 20 to 70 wt. % of a polycarbonate homopolymer or copolymer comprising repeat carbonate units having the following structure (17):
wherein R 1 and R 2 are independently at each occurrence a C 1 -C 6 alkyl, n is an integer having a value of 0 to 4, p is an integer having a value of 1 to 4, and T is selected from the group consisting of C 5 -C 10 cycloalkanes attached to the aryl groups at one or two carbons, C 1 -C 5 alkyl groups, C 6 -C 13 aryl groups, and C 7 -C 13 aryl alkyl groups;
from 20 to 70 wt. % of a poly(alkyl(meth)acrylate), wherein the alkyl group is straight or branched-chain, and has 1 or 2 carbons atoms; and
from 10 to 30 wt. % of an impact modifier or combination of impact modifiers.
16 . The composition of claim 15 , wherein the repeat carbonate units of formula (17) have the following structure:
wherein R 1 and R 2 are independently selected from the group consisting of C 1 -C 6 alkyl; X represents CH 2 ; m is an integer from 4 to 9; n is an integer from 1 to 4; and p is an integer from 1 to 4, with the proviso that at least one of R 1 or R 2 is in the 3 or 3′ position.
17 . The composition of claim 16 , wherein the repeat carbonate structures have the structure
18 . The composition of claim 15 , wherein the impact modifier comprises ABS, polycarbonate-polysiloxane copolymer, or a combination of ABS and polycarbonate-polysiloxane copolymer.
19 . An article comprising the composition of claim 15 .
20 . The article of claim 19 , wherein the article has a scratch resistance of less than 17 when measured according to the ISO 1518.
21 . A thermoplastic composition comprising in combination
from 20 to 70 wt. % of a polycarbonate homopolymer or copolymer comprising repeat carbonate units having the following structure:
from 20 to 70 wt. % of a poly(alkyl(meth)acrylate), wherein the alkyl group is straight or branched-chain, and has 1 or 2 carbons atoms; and
from 10 to 30 wt. % of an impact modifier or combination of impact modifiers.
22 . An article comprising the composition of claim 21 .
23 . A thermoplastic composition comprising in combination
from 20 to 70 wt. % of a polycarbonate homopolymer or copolymer comprising repeat carbonate units having the following structure:
from 20 to 70 wt. % of a poly(alkyl(meth)acrylate), wherein the alkyl group is straight or branched-chain, and has 1 or 2 carbons atoms; and
from 10 to 30 wt. % of an impact modifier comprising ABS, polycarbonate-polysiloxane copolymer, or a combination of ABS and polycarbonate-polysiloxane copolymer,
wherein the composition, when molded into a test article, has a scratch resistance of less than 17 when measured according to ISO 1518.