Method for producing diene-based graft copolymer resin and diene-based graft copolymer resin

A method for producing a diene-based graft copolymer resin, the method comprising:

• adding, into a reactor, a polymerization solution comprising a diene-based rubber polymer, an aromatic vinyl-based monomer, a vinyl cyan-based monomer, a polymerization initiator, and a reaction solvent, and polymerizing the polymerization solution to prepare a polymer;
• recovering a solution comprising unreacted monomers and a reaction solvent from the polymerization solution, dispersing a releasing agent in a recovered solution, and then adding the solution into the front end of a volatilization tank;
• and
• removing the unreacted monomers and the reaction solvent from the volatilization tank,
• wherein the removing of the unreacted monomers and the reaction solvent from the volatilization tank is carried out at a temperature of 200° C. to 300° C. under a pressure of 10 torr to 100 torr,
• wherein the diene-based rubber polymer includes a polymer of a diene-based monomer,
• wherein the diene-based monomer includes at least one selected from among 1,3-butadiene, isoprene, chloroprene, and piperylene,
• wherein the aromatic vinyl-based monomer includes at least one selected from among styrene, α-methyl styrene, α-ethyl styrene, and p-methyl styrene,
• wherein the vinyl cyan-based monomer includes at least one selected from among acrylonitrile, methacrylonitrile, phenylacrylonitrile and α-chloroacrylonitrile, and
• wherein the releasing agent includes calcium stearate.