| 摘要 |
PURPOSE:To provide a primer for sealing a clay pipe capable of firmly bonding a clay pipe to a urethane joint even in the case of a gas-covered clay pipe, which comprises a hydrolyzable silicon compd. and a polyurethane urea resin. CONSTITUTION:A hydrolyzable silicon compd. (A) is mixed with a polyurethane urea resin (B) in a weight ratio of pref. 9:1-1:9 to prepare an intended primer for sealing a clay pipe. Specific examples of component A include gamma- aminopropyltrimethoxysilane and gamma-mercaptopropyltrimethoxysilane. Component B is suitably a polyurethane urea resin derived from polyester diol (e.g., polycaprolactonediol), an org. diisocyanate (e.g., tolylene diisocyanate), and an amine chain extender (e.g. ethylenediamine).
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