Provided is a method of preparing a graft copolymer, which includes: preparing a liquid maleimide-based monomer; preparing a reaction solution including a diene-based rubber polymer, an aromatic vinyl-based monomer, and a vinyl cyan-based monomer; and adding the liquid maleimide-based monomer and the reaction solution to a reactor and carrying out polymerization. According to the preparation method of the present invention, the amount of the maleimide-based monomer involved in the polymerization can be increased, and the color characteristics, glass transition temperature, and softening temperature of the graft copolymer are improved.

Provided is a method of preparing a graft copolymer, which includes: preparing a liquid maleimide-based monomer; preparing a reaction solution including a diene-based rubber polymer, an aromatic vinyl-based monomer, and a vinyl cyan-based monomer; and adding the liquid maleimide-based monomer and the reaction solution to a reactor and carrying out polymerization. According to the preparation method of the present invention, the amount of the maleimide-based monomer involved in the polymerization can be increased, and the color characteristics, glass transition temperature, and softening temperature of the graft copolymer are improved.

Provided is a method of preparing a graft copolymer, which includes: preparing a liquid maleimide-based monomer; preparing a reaction solution including a diene-based rubber polymer, an aromatic vinyl-based monomer, and a vinyl cyan-based monomer; and adding the liquid maleimide-based monomer and the reaction solution to a reactor and carrying out polymerization. According to the preparation method of the present invention, the amount of the maleimide-based monomer involved in the polymerization can be increased, and the color characteristics, glass transition temperature, and softening temperature of the graft copolymer are improved.

A thermoplastic resin composition of the present invention comprises: a polycarbonate resin; a rubber-modified vinyl-based graft copolymer; a large particle size rubbery polymer having an average particle size of about 400 to about 1,500 nm; an aromatic vinyl-based copolymer resin; a phosphorus-based flame retardant; talc; wollastonite; a maleic anhydride grafted rubbery polymer; and a black pigment. The thermoplastic resin composition is superior in terms of adhesion to metal, strength, flame retardancy, fluidity, and appearance.

A thermoplastic resin composition of the present invention comprises: a polycarbonate resin; a rubber-modified vinyl-based graft copolymer; a large particle size rubbery polymer having an average particle size of about 400 to about 1,500 nm; an aromatic vinyl-based copolymer resin; a phosphorus-based flame retardant; talc; wollastonite; a maleic anhydride grafted rubbery polymer; and a black pigment. The thermoplastic resin composition is superior in terms of adhesion to metal, strength, flame retardancy, fluidity, and appearance.

An emulsion polymerization process for preparation of ABS graft copolymer latex having reduced residual monomer content, wherein a grafting step c) comprises the steps: c1): feeding of 10 to 45 wt.-% of styrene and acrylonitrile in one portion to agglomerated butadiene rubber latex and addition of redox system initiator, then polymerization; c2): feeding remaining monomers in portions or continuously and further addition of redox system initiator; c3): addition of inorganic free radical initiator and continuation of polymerization, leads to ABS graft copolymers and thermoplastic molding compositions which can be used in the automotive industry.

An emulsion polymerization process for preparation of ABS graft copolymer latex having reduced residual monomer content, wherein a grafting step c) comprises the steps: c1): feeding of 10 to 45 wt.-% of styrene and acrylonitrile in one portion to agglomerated butadiene rubber latex and addition of redox system initiator, then polymerization; c2): feeding remaining monomers in portions or continuously and further addition of redox system initiator; c3): addition of inorganic free radical initiator and continuation of polymerization, leads to ABS graft copolymers and thermoplastic molding compositions which can be used in the automotive industry.

Disclosed in the present invention are ABS rubber powder with a low impurity content, a preparation method therefor, and an ABS resin. The ABS rubber powder is treated by using the following steps: washing the ABS rubber powder with a washing solution I, and monitoring the content of soluble organic carbon in the ABS rubber powder until the content of soluble organic carbon in the ABS rubber powder is less than or equal to 9000 ppm, so as to obtain the ABS rubber powder with the low impurity content. In the present invention, by controlling the content of soluble organic carbon or the contents of soluble organic carbon and iron ions in the ABS powder, the ABS resin with a low yellow index of less than or equal to 18 is obtained.

Disclosed in the present invention are ABS rubber powder with a low impurity content, a preparation method therefor, and an ABS resin. The ABS rubber powder is treated by using the following steps: washing the ABS rubber powder with a washing solution I, and monitoring the content of soluble organic carbon in the ABS rubber powder until the content of soluble organic carbon in the ABS rubber powder is less than or equal to 9000 ppm, so as to obtain the ABS rubber powder with the low impurity content. In the present invention, by controlling the content of soluble organic carbon or the contents of soluble organic carbon and iron ions in the ABS powder, the ABS resin with a low yellow index of less than or equal to 18 is obtained.

Disclosed in the present invention are ABS rubber powder with a low impurity content, a preparation method therefor, and an ABS resin. The ABS rubber powder is treated by using the following steps: washing the ABS rubber powder with a washing solution I, and monitoring the content of soluble organic carbon in the ABS rubber powder until the content of soluble organic carbon in the ABS rubber powder is less than or equal to 9000 ppm, so as to obtain the ABS rubber powder with the low impurity content. In the present invention, by controlling the content of soluble organic carbon or the contents of soluble organic carbon and iron ions in the ABS powder, the ABS resin with a low yellow index of less than or equal to 18 is obtained.