Non-glossy rubber modified aromatic vinyl-vinyl cyanide copolymer and method for continuously preparing the same

1. A method for continuously preparing a non-glossy rubber modified aromatic vinyl-vinyl cyanide copolymer comprising:

preparing a reaction solution by mixing a mixed solution comprising an aromatic vinyl compound, a vinyl cyanide compound, a diene-based rubber and a solvent with a polymerization initiator and a molecular weight control agent;

polymerizing the reaction solution by continuously introducing the reaction solution into a first reactor to a conversion rate of about 30 to about 40%; and

polymerizing a polymerization product prepared from the first reactor by continuously introducing the polymerization product into a second reactor to a conversion rate of about 70 to about 80%.

2. The method of claim 1 , wherein said solvent comprises ethyl benzene, xylene, toluene, or a combination thereof.

3. The method of claim 1 , wherein said diene-based rubber has a solution viscosity of about 150 to about 300 cps in 5% styrene solution.

4. The method of claim 1 , wherein said mixed solution comprises about 40 to about 60% by weight of an aromatic vinyl compound, about 10 to about 25% by weight of a vinyl cyanide compound, about 7 to about 20% by weight of a diene-based rubber, and about 5 to about 30% by weight of a solvent.

5. The method of claim 1 , wherein said first reactor has a stirring rate of about 60 to about 150 rpm, and said second reactor has a stirring rate of about 50 to about 100 rpm.

6. The method of claim 1 , wherein said polymerization initiator has a half-life of about 10 minutes or less at polymerization temperature.

7. The method of claim 6 , wherein said polymerization initiator is 1,1-bis(t-butylperoxy)-2-methylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2-bis(4,4-di-t-butylperoxy cyclohexane)propane, t-hexyl peroxy isopropyl monocarbonate, t-butyl peroxymaleic acid, t-butyl peroxy-3,5,5-trimethyl hexanoate, t-butyl peroxylaurate, 2,5-dimethyl-2,5-bis(m-toluoyl peroxy)hexane, t-butyl peroxy isopropyl monocarbonate, t-butyl peroxy 2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-bis(benzoyl peroxy)hexane, t-butyl peroxyacetate, 2,2-bis(t-butyl peroxy)butane, t-butyl peroxybenzoate, n-butyl-4,4-bis(t-butyl peroxy) valerate, or a combination thereof.

8. The method of claim 1 , further comprising devolatilizing a polymerization product prepared from the second reactor.

9. The method of claim 8 , wherein said devolatilizing step comprises directing the polymerization product through serially connected first and second devolatizing apparatus to remove unreacted monomer.

10. The method of claim 9 , wherein said first devolatilizing apparatus is operated under the conditions of about 160 to about 240° C. and about 100 to about 600 Torr, and said second devolatilizing apparatus is operated under the conditions of about 210 to about 250° C. and about 1 to about 50 Ton.

11. The method of claim 5 , wherein said second reactor has a stirring rate of about 60 to about 80 rpm.

12. The method of claim 5 , wherein said second reactor has a stirring rate of about 65 to about 90 rpm.

13. The method of claim 1 , wherein the method produces a non-glossy rubber modified aromatic vinyl-vinyl cyanide copolymer including a diene-based rubber, wherein the rubber comprises a dispersed phase having an average rubber particle diameter of about 6 to about 20 μm and a span of about 1.2 to about 2.8.

14. The method of claim 13 , wherein said aromatic vinyl-vinyl cyanide copolymer comprises about 65 to about 85% by weight of an aromatic vinyl compound and about 15 to about 35% by weight of a vinyl cyanide compound.

15. The method of claim 14 , wherein said aromatic vinyl-vinyl cyanide copolymer comprises about 70 to about 83% by weight of said aromatic vinyl compound and about 17 to about 30% by weight of said vinyl cyanide compound.

16. The method of claim 13 , wherein said non-glossy rubber modified aromatic vinyl-vinyl cyanide copolymer has a 60° gloss value of about 1 to about 10 measured for a test specimen with a thickness of 2 mm using a BYK-Gardner gloss meter and a 60° gloss value of about 1 to about 5.5 measured for a test specimen with a thickness of 0.02 mm using a BYK-Gardner gloss meter.