초록 ▼

Graft copolymers are prepared by means of a two-step polymerization process, in emulsion: in the first step, a vinylaromatic monomer and an acryl or metacryl monomer are grafted on a monomodal polybutadiene latex constituted of particles of diameter comprised within the range of from 800 to 2500 Å.

Graft copolymers are prepared by means of a two-step polymerization process, in emulsion: in the first step, a vinylaromatic monomer and an acryl or metacryl monomer are grafted on a monomodal polybutadiene latex constituted of particles of diameter comprised within the range of from 800 to 2500 Å. The polymerization/grafting reaction is continued up to a 70-90% conversion, at which time a further portion of monomodal polybutadiene is added, together with further amounts of said monomers, always in emulsion.

대표청구항 ▼

An emulsion polymerization process for the preparation of grafted polymers comprising: (a) in a first stage of the process, charging a reaction space with a monomodal polybutadiene latex having a particle diameter of from 800 to 2500 Angstroms in an amount from 80 to 90% of the total polybutandiene

An emulsion polymerization process for the preparation of grafted polymers comprising: (a) in a first stage of the process, charging a reaction space with a monomodal polybutadiene latex having a particle diameter of from 800 to 2500 Angstroms in an amount from 80 to 90% of the total polybutandiene latex employed in the entire process; (b) continuously feeding said reaction space with monomers of styrene and acrylonitrile in a weight ratio of from 60:40 to 80:20 at a temperature of from 50°to 80°C. in the presence of an initiator until 70 to 90% of said monomers react with said polybutadiene latex to form the grafted polymer; and (c) in a second stage of the process, feeding to the grafted polymer of the first stage the remaining amount of the polybutadiene latex and an additional amount of said monomers of styrene and acrylonitrile at a temperature of 50°-80°C. in the presence of initiator until 94-96% of the monomers have reacted with the polybutadiene latex to form said grafted polymer.