Neilds & Lemack
Coating composition for precoated steel sheet, precoated steel sheet, and process for preparing the same
 The invention relates to a thermosetting coating composition for precoated steel sheets which are required to have high hardness, good workability and stain resistance, to a precoated steel sheet having a film of the coating composition, and to a method for producing such precoated steel sheets. The coating composition for precoated steel sheets of the invention consists essentially of a polyol and contains a specific compound and a curing agent composed of polyisocyanate compounds added thereto, in which the curing agent is a mixture composed of a blocked polyisocyanate compound as obtained by blocking one or more polyisocyanate compounds selected from polyisocyanates of the following group (a) and their derivatives, and a blocked polyisocyanate compound as obtained by blocking one or more polyisocyanate compounds selected from polyisocyanates of the following group (b) and their derivatives: PA1 (a) 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate, naphthalene-1,5-diisocyanate; PA1 (b) hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate. The coating composition forms a coating film having good workability, high hardness and good stain resistance. 
NKK Corporation
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Y10T Y10T C08G Y10T C08G C08G C08G C08G C08G Y10T Y10T C08G C08G C09D
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Takashi Masaru Masaaki Hiroyuki Mamoru Yasuhiro Kenichi Yasuyuki Katsuyoshi Keiji Keiichi
Anyashiki Sagiyama Yamashita Kato Ehara Toyoda Sasaki Kajita Tanaka Yoshida Kotani