Polycarbonate resin, composition of said resin, and molded article of said resin
View Patent ↗To provide a polycarbonate resin composition having improved flame retardancy and moldability. A polycarbonate resin having a ratio of the melt viscosity η 10 measured at 300° C. at a shear rate of 10 sec −1 to the melt viscosity η 1000 measured at 300° C. at a shear rate of 1000 sec −1 (η 10 /η 1000 ) of at least 3 and at most 8, a branch parameter G=[η]/[η]lin of at least 0.80 and at most 0.94, and a pencil hardness of at least HB.
1. A branched polycarbonate resin, which has:
a ratio of the melt viscosity η 10 measured at 300° C. at a shear rate of 10 sec −1 to the melt viscosity η 1000 measured at 300° C. at a shear rate of 1,000 sec −1 (η 10 /η 1000 ) of at least 3 and at most 8;
a branch parameter G=[η]/[η] lin of at least 0.80 and at most 0.94; and
a pencil hardness of at least HB,
wherein:
[η] represents the intrinsic viscosity (dl/g) of the branched polycarbonate resin in a methylene chloride solvent at 20° C.; and
[η] lin represents the intrinsic viscosity in a methylene chloride solvent at 20° C. of a linear polycarbonate having the same weight average molecular weight as the branched polycarbonate resin as measured by a GPC method with a general purpose calibration curve.
2. The polycarbonate resin according to claim 1 , comprising at least one structural unit represented by formula (1):
wherein:
X represents a single bond, a substituted or non-substituted alkylene group, a substituted or non-substituted alkylidene group, an oxidized or non-oxidized sulfur atom, or an oxygen atom;
R 1 and R 2 independently represent a substituted or non-substituted C 1-20 alkyl group or a substituted or non-substituted aryl group; and
R 3 and R 4 independently represent a hydrogen atom, a substituted or non-substituted C 1-20 alkyl group, or a substituted or non-substituted aryl group.
3. The polycarbonate resin according to claim 2 , wherein, in the formula (1):
each of R 1 and R 2 independently represent a methyl group bonded to the carbon atom at the 2-position of the phenoxy group;
each of R 3 and R 4 independently represent a hydrogen atom bonded to the carbon atom at the 6-position of the phenoxy group; and
X represents an isopropylidene group.
4. The polycarbonate resin according to claim 1 , comprising at least one structural unit represented by formula (2):
wherein R 1 and R 2 independently represent a substituted or non-substituted C 1-20 alkyl group, or a substituted or non-substituted aryl group.
5. The polycarbonate resin according to claim 1 , which is obtained by ester exchange of an aromatic dihydroxy compound represented by formula (3) and a carbonic diester:
wherein:
X represents a single bond, a substituted or non-substituted alkylene group, a substituted or non-substituted alkylidene group, an oxidized or non-oxidized sulfur atom, or an oxygen atom;
R 1 and R 2 independently represent a substituted or non-substituted C 1-20 alkyl group or a substituted or non-substituted aryl group; and
R 3 and R 4 independently represent a hydrogen atom, a substituted or non-substituted C 1-20 alkyl group, or a substituted or non-substituted aryl group.
6. A polycarbonate resin composition, comprising:
(i) the polycarbonate resin of claim 1 ; and
(ii) a polycarbonate resin comprising at least one structural unit represented by formula (4):
wherein X represents a single bond, a substituted or non-substituted alkylene group, a substituted or non-substituted alkylidene group, an oxidized or non-oxidized sulfur atom, or an oxygen atom.
7. The polycarbonate resin composition according to claim 6 , comprising from 1 to 45 wt % of the polycarbonate resin (i), based on a total weight of the polycarbonate resin composition.
8. A flame retardant-containing polycarbonate resin composition, comprising the polycarbonate resin of claim 1 and a flame retardant.
9. The flame retardant-containing polycarbonate resin composition according to claim 8 , wherein the flame retardant is at least one selected from the group consisting of a metal sulfonate flame retardant, a halogen-containing compound flame retardant, and a phosphorus-containing compound flame retardant.
10. The flame retardant-containing polycarbonate resin composition according to claim 9 , comprising from 0.04 to 0.3 part by weight of the metal sulfonate flame retardant per 100 parts by weight of the polycarbonate resin.
11. The flame retardant-containing polycarbonate resin composition according to claim 9 , comprising from 5 to 30 parts by weight of the halogen-containing compound flame retardant per 100 parts by weight of the polycarbonate resin.
12. The flame retardant-containing polycarbonate resin composition according to claim 9 , comprising from 3 to 15 parts by weight of the phosphorous-containing compound flame retardant per 100 parts by weight of the polycarbonate resin.
13. A flame retardant-containing polycarbonate resin composition, comprising the polycarbonate resin composition of claim 6 and a flame retardant.
14. The flame retardant-containing polycarbonate resin composition according to claim 13 , wherein the flame retardant is at least one selected from the group consisting of a metal sulfonate flame retardant, a halogen-containing compound flame retardant, and a phosphorus-containing compound flame retardant.
15. The flame retardant-containing polycarbonate resin composition according to claim 14 , comprising from 0.04 to 0.3 part by weight of the metal sulfonate flame retardant per 100 parts by weight of the polycarbonate resin composition.
16. The flame retardant-containing polycarbonate resin composition according to claim 14 , comprising from 5 to 30 parts by weight of the halogen-containing compound flame retardant per 100 parts by weight of the polycarbonate resin composition.
17. The flame retardant-containing polycarbonate resin composition according to claim 14 , comprising from 3 to 15 parts by weight of the phosphorous-containing compound flame retardant per 100 parts by weight of the polycarbonate resin composition.
18. A molded article of polycarbonate resin obtained by molding the flame retardant-containing polycarbonate resin composition of claim 8 , whereing the molded article:
satisfies the V-0 classification in the flammability test of UL94 with respect to a test specimen having a thickness of at most 2 mm;
has a haze of at most 1.0 with respect to a test specimen having a thickness of 3 mm based on the standard of JIS K7136; and
has a surface hardness of at least HB.
19. A molded article of polycarbonate resin obtained by molding the flame retardant-containing polycarbonate resin composition of claim 13 , wherein the molded article:
satisfies the V-0 classification in the flammability test of UL94 with respect to a test specimen having a thickness of at most 2 mm;
has a haze of at most 1.0 with respect to a test specimen having a thickness of 3 mm based on the standard of JIS K7136; and
has a surface hardness of at least HB.