| 摘要 |
PROBLEM TO BE SOLVED: To obtain a vinyl chloride polymer having good properties such as heat stability at good efficiency by using a polymerization initiator composition prepared by mixing two specified peracid esters with each other in a specified ratio in the polymerization of vinyl chloride. SOLUTION: This polymerization initiator composition is used for the polymerization of a vinyl chloride monomer and prepared by mixing peracid esters (A) and (B) of the formula [wherein R1 to R3 are each a 1C or higher alkyl; R4 is a phenyl; the total number of carbon atoms of R1 to R3 in the compound A is 7; and the total number of carbon atoms of R1 to R3 in the compound B is 11] with each other in an A/B weight ratio of 70/30 to 90/10 as the effective component. When this composition is used in the polymerization of vinyl chloride monomers (other copolymerizable monomers may be included), it can give a vinyl chloride polymer having good properties in high yields. These peracid esters are obtained by reacting the corresponding acid chlorides with cumyl hydroperoxide in the presence of a catalyst such as NaOH. Their examples include cumylperoxy-2,2,3-trimethyl hexanoate and cumylperoxy-2,2,8,8- tetramethyl nonanoate. |
