| 摘要 |
PURPOSE:A coating composition which forms a film of coating having improved wear resistance and has improved shelf stability, consisting of a partial condensate of an organotrialkoxysilane, colloidal silica, a lower alcohol, water and a polyhydric carboxylic acid anhydride. CONSTITUTION:(A) 100pts.wt. organotrialkoxysilane shown by the formula (R1 is 1-2C alkyl and R2 is 1-3C alkyl), preferably methyltriethoxysilane is blended with (B) 0.05-4pts.wt. polyfunctional carboxylic acid anhydride having a cyclic structure such as phthalic anhydride, etc., then reacted with (C) an aqueous solution of weakly basic colloidal silica at 30-50 deg.C and the prepared reaction product is mixed with (D) a lower aliphatic alcohol to adjust solvent balance. The resultant substance is further concentrated by ultrafiltration and preferably further incorporated with a weakly basic compound as a curing catalyst to give the aimed composition which is at pH6-7 and has >=0.005wt% component B.
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