摘要：

A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising an alkaline solution containing (A) a condensation product of (A-1) a diamino aromatic compound having the general formula (1):wherein R is at least one group selected from the group consisting of -OH, -COOH and -SOH, R is a hydrogen atom or a substituent group, X is a single bond or a divalent group of the formula -CH=CH-, and are not simultaneously zero, when a plurality of R groups are present they may be identical or different, and when a plurality of R groups are present they may be identical or different, with (A-2) a quinone compound, and a process for producing a polymer using the agent are disclosed. Polymer scale deposition can be prevented not only on the areas located in the liquid phase region but also on the areas around the interface between gas and liquid phases in a polymerization vessel, and a polymeric product can be obtained which has a reduced number of fish eyes when processed into formed products.

展开