| abstract |
1402658 Polyurethane coating compositions BAYER AG 30 May 1973 [30 May 1972 1 Feb 1973] 25716/73 Heading C3R A binder for a coating composition comprises a reactive mixture having a viscosity of 19 to 400 seconds measured in a no. 4 DIN cup, containing (a) at least one organic polyisocyanate having aliphatically bound isocyanate groups, (b) at least one polyhydroxyl compound with a molecular weight between 200 and 2000, the hydroxyl groups being aliphatically bound, and which is free from ether groups, and (c) 0 to 40% by weight of the total mixture of a monohydric and/or polyhydric alcohol with a molecular weight below 200, the NCO/OH ratio in the mixture being between 0À8 :1 and 1À2 :1. In examples the polyisocyanates (a) are a tris- (isocyanatohexyl)-biuret, an isocyanurate/uretdione mixture prepared by oligomerization of hexamethylene diisocyanate and 4,4<SP>1</SP>-diisocyanatodicyclohexylmethane; the polyhydroxyl compounds, (b) are castor oil and hydroxylcontaining polyesters prepared from phthalic acid, ethylene glycol, trimethylolpropane, adipic acid, 2-ethyl-hexanoic acid and maleic acid; the monohydric and polyhydric alcohols (c) are butyl glycollate, 2-ethylhexane-1,3-diol and trimethylolpropane; other ingredients include silicone oil, lead octoate, titanium dioxide, dibutyl tin dilaurate, polyacrylate, fluorinated hydrocarbon, cellulose acetobutyrate and ethyl glycol acetate. |