The present invention relates to ABS
thermoplastic resin and preparation thereof, and particularly to a process for preparing an ABS graft
copolymer comprising the step of introducing to a) 40 to 80 weight parts of rubber latex comprising i) 10 to 50 weight parts of large
diameter polybutadiene rubber latex having a particle
diameter of 2500 to 3500 Å, gel contents of 60 to 80%, and a swelling index to 12 to 30, and ii) 50 to 90 weight parts of large
diameter rubber latex having a particle diameter of 2500 to 3500 Å, gel contents of 81 to 97%, and a swelling index of 18 to 40, b) 20 to 60 weight parts of a
monomer mixture of two or more kinds selected from a group consisting of aromatic vinyl compounds and vinyl
cyanide compounds to prepare a graft
copolymer, wherein 5 to 30 wt % of the
monomer mixture is introduced as a batch and simultaneously 70 to 95 wt % of the
monomer mixture is started to be continuously introduced in an emulsified state, and a
thermoplastic resin composition using the same. According to the process of the present invention, control of
polymerization heat is easy even at high
solid contents, and
polymerization cohesion contents can be minimized and thus ABS
thermoplastic resin having superior
impact resistance, gloss, and coloring property can be provided.