摘要:
In a novel method of homo- or copolymerization of vinyl chloride, a specified coating agent is applied on the surfaces of the portions which will become into contact with the vinyl chloride monomer during the polymerization process. The coating agent is in a form of an aqueous solution of a modified condensation product of phenol and aldehyde, the pH of the solution being adjusted in a range that the product is dissolved at an ambient temperature upon coating of the solution and separates out of the solution upon being heated on the surfaces. The wall surface of the polymerization tank and the like is then coated with a thin film of the coating agent having a uniform thickness and being strongly adhered to the wall surface, thereby providing an excellent effect of preventing adhesion of the product polymer to the wall surface.
摘要:
A method for polymerizing vinyl chloride comprises polymerizing vinyl chloride in an aqueous medium or bulk-polymerizing vinyl chloride, wherein the inner wall of a polymerizer and parts of devices which come in contact with the monomer during the polymerization are coated, prior to the polymerization, with a reaction product having a molecular weight ranging from 500 to 100,000, obtained by condensing a polyhydric phenol and sulfur dichloride in the presence of a Lewis acid as a catalyst. The amount of the polymer adhered to the polymerizer during polymerization of vinyl chloride is substantially lowered and the adhered polymer can be easily washed away through simple water washing according to the foregoing method. Moreover, the method does not adversely affect the reaction time and the quality of the resulting product at all.