Patent ID: 9611409
Date: 2017-04-04
CPC Classifications: B29C,C08J,C08K,C09B,C09D,C09J

Claim:
1. An essentially colorless primer for use in preparing a PVC or CPVC plastic object for bonding with a solvent cement, the primer comprising an organic solvent capable of at least partially softening the surfaces of the plastic object to which it is applied and an essentially colorless color-forming chemical in the organic solvent, the essentially colorless color-forming chemical being chemically activated by at least one of the plastic object to which it is applied, a component in or on the plastic, a developer included in a subsequently applied solvent cement, and is not activatable by heat, activation causing the essentially colorless color-forming chemical to develop a visually noticeable color thereby identifying the surfaces of the plastic object to which the primer has been applied, wherein the primer does not contain a developer that must be activated for use.