Method for preparing graft copolymer, graft copolymer and thermoplastic resin molded article
The present invention relates to a method for preparing a graft copolymer, which includes polymerizing a first conjugated diene-based polymer, a second conjugated diene-based polymer, an aromatic vinyl-based monomer and a vinyl cyan-based monomer, wherein particle size distribution of the first conjugated diene-based polymer is 0.346 to 0.404, and particle size distribution of the second conjugated diene-based polymer is 0.196 to 0.304, a graft copolymer and a thermoplastic resin molded article.
1. A method for preparing a graft copolymer, the method comprising:
polymerizing a first conjugated diene-based polymer, a second conjugated diene-based polymer, an aromatic vinyl-based monomer and a vinyl cyan-based monomer,
wherein particle size distribution of the first conjugated diene-based polymer is 0.346 to 0.404, and
particle size distribution of the second conjugated diene-based polymer is 0.196 to 0.304.
2. The method for preparing a graft copolymer according to claim 1 , wherein average particle diameters of the first conjugated diene-based polymer and the second conjugated diene-based polymer are 0.2 to 0.4 μm, respectively.
3. The method for preparing a graft copolymer according to claim 1 , wherein the particle size distribution of the first conjugated diene-based polymer is 0.35 to 0.4.
4. The method for preparing a graft copolymer according to claim 1 , wherein the first and second conjugated diene-based polymers are respectively prepared by polymerizing a conjugated diene-based monomer to prepare a small-size conjugated diene-based polymer, and then, enlarging the small-size conjugated diene-based polymer.
5. The method for preparing a graft copolymer according to claim 4 , wherein the small-size diene-based rubbery polymer has the gel content of 90% or more.
6. The method for preparing a graft copolymer according to claim 1 , wherein the particle size distribution of the second conjugated diene-based polymer is 0.2 to 0.3.
7. The method for preparing a graft copolymer according to claim 1 , wherein a weight ratio of the first conjugated diene-based polymer and the second conjugated diene-based polymer is 30:70 to 80:20.
8. The method for preparing a graft copolymer according to claim 1 , wherein a weight ratio of the aromatic vinyl-based monomer and the vinyl cyan-based monomer is 80:20 to 65:35.
9. The method for preparing a graft copolymer according to claim 1 , further adding a mercaptan-based compound and an aromatic vinyl-based dimer during polymerizing.
10. The method for preparing a graft copolymer according to claim 9 , wherein the mercaptan-based compound and the aromatic vinyl-based dimer are added in a weight ratio of 60:40 to 70:30.
11. A graft copolymer prepared by the preparation method according to claim 1 , and having a graft ratio of 37% or more and a weight average molecular weight of a shell of 75,000 g/mol or more.
12. A thermoplastic resin molded article manufactured from a thermoplastic resin composition comprising:
the graft copolymer according to claim 11 ; and
a copolymer comprising a unit derived from an aromatic vinyl-based monomer and a unit derived from a vinyl cyan-based monomer,
wherein a remaining amount of volatile organic compounds is 1,000 ppm or less.