Polycarbonate resin composition, method for producing same and molded article of this resin composition

1. A molded article of polycarbonate resin, comprising as a blend:

a polycarbonate resin (a) and a polycarbonate resin (b) having structural units different from the polycarbonate resin (a);

wherein the polycarbonate resin (a) comprises structural units derived from a compound of formula (1):

wherein

each of R 1 and R 2 which are independent of each other, is a substituted or non-substituted C 1-20 alkyl group or a substituted or non-substituted aryl group, each of R 3 and R 4 which are independent of each other, is a hydrogen atom, a substituted or non-substituted C 1-20 alkyl group or a substituted or non-substituted aryl group, and X is a single bond, a carbonyl group, a substituted or non-substituted alkylidene group, an oxidized or non-oxidized sulfur atom, or an oxygen atom, with the proviso that X is not 1.1-cyclohexylidene; wherein

a viscosity average molecular weight of the polycarbonate resin (a) is lower than the viscosity average molecular weight of polycarbonate resin (b),

a ratio of the content [S] of the structural units of formula (1) on the surface of the molded article to a content [T] in the entire molded article ([S]/[T]) is higher than 1.00 and at most 2.00, and

wherein

the polycarbonate resin satisfies the following requirements:

(i) the pencil hardness of the polycarbonate resin (a) as specified by ISO 15184 is higher than the pencil hardness of the polycarbonate resin (b) as specified by ISO 15184;

(ii) the glass transition point Tg(a) of the polycarbonate resin (a) and the glass transition point Tg(b) of the polycarbonate resin (b) satisfy the relation of the following Formula:

Tg ( b )−45° C.< Tg ( a )< Tg −10° C.

and (iii) the pencil hardness of the polycarbonate resin composition as specified by ISO 15184 is higher by at least two ranks than the pencil hardness of the polycarbonate resin (b) as specified by ISO 15184.

2. The molded article of claim 1 , wherein the article is injection-molded.

3. The molded article of claim 1 , wherein the ratio ([S]/[T]) is at least 1.01 and at most 1.50.

4. The molded article of claim 1 , wherein the pencil hardness on the surface of the molded article of polycarbonate resin as specified by ISO 15184 is at least HB.

5. The molded article of claim 1 , wherein the structural units (a) are structural units derived from at least one compound selected from the group consisting of formulae (1a) and (1c):

6. The molded article of claim 1 , wherein the polycarbonate resin (b) comprises structural units (b) derived from a compound of formula (2):

7. The molded article of claim 1 , wherein the pencil hardness of the polycarbonate resin (a) as specified by ISO 15184 is at least F.

8. A method for producing the molded article of claim 1 , comprising: melt-kneading or dry-blending the polycarbonate resin (a) and the polycarbonate resin (b), followed by molding.

9. The method of claim 8 , wherein the structural units

(a) are structural units derived from at least one compound selected from the group consisting of formulae (1a) to and (1c):

10. The method of claim 8 , wherein the structural units b) comprise structural units derived from a compound of formula (2):

11. The method of claim 8 , wherein the molding is injection-molding.