Method for preparing vinyl chloride pasty resin

Abstract

A process for preparing a vinyl chloride paste resin comprises the following steps: homogenizing a vinyl chloride monomer in an aqueous medium together with an oil-soluble polymerization initiator to form a first aqueous dispersion, and subjecting the first dispersion to a micro-suspension polymerization wherein a second aqueous dispersion containing a vinyl chloride monomer and a surface active agent is added to the reaction system in such a manner that the addition is started after starting the polymerization but by the time the polymerization conversion of the initially charged monomer reaches 30%, and is terminated by the time the polymerization conversion of the initially charged monomer reaches 95%. The process has an improved productivity since the heat removing area of a jacket of a reactor is prevented from lowering during the polymerization to increase the amount of heat removed and since the polymer yield per unit volume of the reactor is increased.

Description

technical field

[0001] The invention relates to a method for preparing vinyl chloride paste resin, in particular to a microsuspension polymerization method for preparing vinyl chloride resin suitable for paste technology. Background technique

[0002] Microsuspension polymerization involves a homogenization step in which vinyl chloride monomer, water, surfactants, polymerization initiators and other polymerization aids dissolved in the monomer are mixed under high shear in a separate mixing in equipment to form a homogeneous dispersion, and a polymerization step in which the dispersion is transferred to a polymerization apparatus and polymerized under agitation, thereby producing vinyl chloride pasty resin particles having an elementary particle size of about 0.2 to about 3 microns.

[0003] As used herein, the term "vinyl chloride monomer" means vinyl chloride itself or a mixture of vinyl chloride and other monomers copolymerizable with vinyl chloride.

[0004] In microsus...