Glass fiber reinforced polycarbonate resin composition having excellent impact strength and flowability and method for preparing the same

1. A glass fiber reinforced polycarbonate resin composition having good flowability and impact resistance comprising:

(A) 100 parts by weight of a glass fiber reinforced polycarbonate resin; and

(B) about 0.1 to about 10 parts by weight of a modified polyolefin having a polyolefin main chain and a side chain comprising at least one functional group selected from the group consisting of methacrylate groups, acrylate groups, modified ester groups, C6-C12 arylate groups, acrylonitrile groups, and combinations thereof, wherein said side chain is present in an amount of about 24 to about 50% by weight based on the total weight of the modified polyolefin (B).

2. The glass fiber reinforced polycarbonate resin composition of claim 1 , wherein said glass fiber reinforced polycarbonate resin (A) comprises about 40 to about 95% by weight of a polycarbonate resin and about 5 to about 60% by weight of a glass fiber.

3. The glass fiber reinforced polycarbonate resin composition of claim 1 , wherein said modified polyolefin (B) has a repeating unit as shown in Chemical Formula 1:

wherein R 1 is hydrogen or methyl; Y is —COOR 2 , (wherein R 2 is C 1 -C 12 alkyl), glycidyl modified ester, C6-C12 arylate or —CN; m and n are the degree of polymerization and m:n is about 300:1 to about 10:90.

4. The glass fiber reinforced polycarbonate resin composition of claim 1 , wherein said main chain of the modified polyolefin comprises at least about 70% by weight of polyethylene, polypropylene, or ethylene-propylene copolymer.

5. The glass fiber reinforced polycarbonate resin composition of claim 2 , wherein said glass fiber is surface-treated.

6. The glass fiber reinforced polycarbonate resin composition of claim 1 , wherein said resin composition has a melt flow rate (MFR) of about 12 to about 25 g/10 minutes (250° C., 10 kg) measured in accordance with ASTM-D1238; a notch Izod impact strength of about 19 to about 50 kgf·cm/cm measured for a ⅛″ specimen in accordance with ASTM-D256; a brittle fracture rate of about 0 to about 10% as determined by subjecting a specimen of the composition to a chemical treatment comprising submerging the specimen into a paint thinner for 2 minutes and thereafter drying the specimen at 80° C. for 30 minutes and measuring the brittle fracture rate of the chemically treated specimen by dropping a 1 kg sphere onto the specimens at a height of 50 cm 20 times; and a difference in yellow index of about 0.7 measured prior to and after UV irradiation for 3 hours using a colorimeter (Minolta 3600D by CIE Lab.) in accordance with ASTM G53.

7. The glass fiber reinforced polycarbonate resin composition of claim 1 , further comprising an additive selected from the group consisting of UV absorbing agents, inorganic fillers, flame retardants, lubricants, plasticizers, thermal stabilizers, antioxidants, light stabilizers, pigments, dyes, and mixtures thereof.

8. The glass fiber reinforced polycarbonate composition of claim 1 , wherein said composition excludes a core-shell graft copolymer.

9. The glass fiber reinforced polycarbonate resin composition of claim 1 , wherein the modified polyolefin is a branched graft copolymer containing polyolefin as a main chain.

10. A molded article produced from the resin composition as defined in claim 1 .

11. The molded article of claim 10 , wherein said composition excludes a core-shell graft copolymer.

12. A molded article produced from the resin composition as defined in claim 7 .

13. The molded article of claim 12 , wherein said composition excludes a core-shell graft copolymer.

14. A method for preparing a glass fiber reinforced polycarbonate resin composition comprising:

providing about 40 to about 95 parts by weight of a polycarbonate resin and about 0.1 to 10 parts by weight of a branched graft copolymer having a polyolefin main chain and a side chain comprising at least one functional group selected from the group consisting of methacrylate groups, acrylate groups, modified ester groups, C6-C12 arylate groups, acrylonitrile groups, and combinations thereof into a main feeder of an extruder, wherein said side chain is present in an amount of about 24 to about 50% by weight based on the total weight of the branched graft copolymer;

adding about 5 to about 60 parts by weight of a glass fiber through a side feeder of the extruder to form a glass fiber reinforced polycarbonate resin composition; and

operating the extruder at a temperature of about 230 to about 350° C.

15. The method of claim 14 , wherein said branched graft copolymer having a polyolefin main chain is a polyolefin modified with at least one functional group selected from the group consisting of methacrylate groups, acrylate groups, modified ester groups, C6-C12 arylate groups, acrylonitrile groups, and combinations thereof.

16. The method of claim 14 , wherein said resin composition has a melt flow rate (MFR) of about 12 to about 25 g/10 minutes (250° C., 10 kg) measured in accordance with ASTM-D1238; a notch Izod impact strength of about 19 to about 50 kgf·cm/cm measured for a ⅛″ specimen in accordance with ASTM-D256; a brittle fracture rate of about 0 to about 10% as determined by subjecting a specimen of the composition to a chemical treatment comprising submerging the specimen into a paint thinner for 2 minutes and thereafter drying the specimen at 80° C. for 30 minutes and measuring the brittle fracture rate of the chemically treated specimen by dropping a 1 kg sphere onto the specimens at a height of 50 cm 20 times; and a difference in yellow index of about 0.7 measured prior to and after UV irradiation for 3 hours using a colorimeter (Minolta 3600D by CIE Lab.) in accordance with ASTM G53.

17. The method of claim 14 , wherein said composition excludes a core-shell graft copolymer.

18. A method for improving flowability, impact resistance, chemical resistance and light resistance of a glass fiber reinforced polycarbonate resin composition comprising:

employing about 0.1 to about 10 parts by weight of a polyolefin modified with at least one functional group selected from the group consisting of methacrylate groups, acrylate groups, modified ester groups, C6-C12 arylate groups, acrylonitrile groups, and combinations thereof per 100 parts by weight of a glass fiber reinforced polycarbonate resin, wherein the functional group is present in an amount of about 24 to about 50% by weight based on the total weight of the modified polyolefin.

19. The method of claim 18 , wherein said composition excludes a core-shell graft copolymer.

20. The method of claim 19 , wherein said composition excludes a acrylonitrile-butadiene-styrene graft copolymer resin.