Thermoplastic resin composition having excellent low gloss characteristic and scratch resistance, and method for preparing the same

1. A thermoplastic resin composition having excellent low gloss characteristic and scratch resistance, the composition comprising:

(A) about 80 to about 95% by weight of a continuous phase formed of a terpolymer of (meth)acrylic acid alkyl ester-aromatic vinyl-cyanide vinyl compound; and

(B) about 5 to about 20% by weight of rubber particles as a dispersed phase, wherein said rubber particles are butadiene rubber particles with 0 wt % styrene monomer and wherein said rubber particles have an average particle diameter of about 3 to about 10 μm,

wherein said terpolymer of (meth)acrylic acid alkyl ester-aromatic vinyl-cyanide vinyl compound (A) is a terpolymer 85 to 90% by weight of (meth)acrylic acid alkyl ester, about 5 to 12% by weight of an aromatic vinyl compound, and about 1 to about 10% by weight of a cyanide vinyl compound.

2. The thermoplastic resin composition of claim 1 , wherein said terpolymer of (meth)acrylic acid alkyl ester-aromatic vinyl-cyanide vinyl compound (A) forms a continuous phase, and the butadiene rubber (B) forms a dispersed phase in the form of spherical particles.

3. The thermoplastic resin composition of claim 1 , wherein said butadiene rubber has a solution viscosity of about 25 to about 100 cps in 5% styrene solution.

4. The thermoplastic resin composition of claim 1 , wherein:

said (meth)acrylic acid alkyl ester is methylmethacrylate, ethylmethacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, or a combination thereof;

said aromatic vinyl compound is styrene, α-methyl styrene, p-methyl styrene, or a combination thereof; and

said cyanide vinyl compound is acrylonitrile, methacrylonitrile, ethacrylonitrile, or a combination thereof.

5. The thermoplastic resin composition of claim 2 , wherein said continuous phase consists of said terpolymer of (meth)acrylic acid alkyl ester-aromatic vinyl-cyanide vinyl compound (A) having a weight average molecular weight of about 60,000 to about 150,000.

6. A method for preparing a thermoplastic resin composition having excellent low gloss characteristic and scratch resistance, the method comprising:

preparing a reaction solution by mixing a monomer mixture comprising about 70 to about 90% by weight of (meth)acrylic acid alkyl ester, about 5 to about 20% by weight of an aromatic vinyl compound, and about 1 to about 10% by weight of a cyanide vinyl compound with butadiene rubber particles with 0 wt % styrene monomer having an average particle diameter of about 3 to about 10 μm; and

polymerizing the reaction solution by continuously introducing the reaction solution into a plurality of serially connected reactors to a final monomer conversion of about 50 to about 70%.

7. The method of claim 6 , wherein said reaction solution comprises about 87 to about 97% by weight of a monomer mixture and about 3 to about 13% by weight of a butadiene rubber.

8. The method of claim 6 , wherein said butadiene rubber has a solution viscosity of about 25 to about 100 cps in 5% styrene solution.

9. The method of claim 6 , wherein said plurality of reactors comprise 2 to 5 reactors.

10. The method of claim 6 , wherein said reaction solution further comprises about 5 to about 20 parts by weight of a solvent, about 0.01 to about 0.2 parts by weight of an initiator, and about 0.1 to about 1 part by weight of a molecular weight control agent.

11. The thermoplastic resin composition of claim 1 , wherein said thermoplastic resin composition has a pencil hardness of HB or more, a scratch width of about 310 μm or less measured by a ball-type scratch profile test, and a gloss of about 60 or less measured using a 60 degree gloss meter.

12. The thermoplastic resin composition of claim 1 , wherein said butadiene rubber has an average particle diameter of about 3 to about 6 μm.

13. The thermoplastic resin composition of claim 1 , comprising (A) about 85 to about 95% by weight of said terpolymer of (meth)acrylic acid alkyl ester-aromatic vinyl-cyanide vinyl compound; and (B) about 5 to about 15% by weight of said butadiene rubber.

14. The method of claim 6 , wherein the monomer mixture comprises about 85 to about 90% by weight of (meth)acrylic acid alkyl ester.

15. The method of claim 14 , wherein the monomer mixture comprises about 5 to 12% by weight of said aromatic vinyl compound.

16. The method of claim 6 , wherein said thermoplastic resin composition has a pencil hardness of HB or more and a gloss of about 40 to 45 measured using a 60 degree gloss meter.

17. The thermoplastic resin composition of claim 1 , wherein said thermoplastic resin composition has a pencil hardness of HB or more and a gloss of about 40 to 45 measured using a 60 degree gloss meter.