| 摘要 |
<p>1322049 Coatings REICHHOLD-ALBERTCHEMIE AG 8 Dec 1970 [18 Dec 1969] 58257/70 Heading B2E [Also in Division C3] A coating composition for galvanised iron, zinc or aluminium comprises solution of (A) 70-80% of a copolymer of (a) 30-37.5% of styrene, (b) 20-30% of n-butyl acrylate or methacrylate or 2-ethylhexyl acrylate, (c) 8-12% of acrylic or methacrylic acid and (d) 30-36% of glycidyl esters ofα-branched alkanoic acids having the overall formula C 12-14 H 22-26 O 3 , the percentages of (a)-(d) totalling 100, the copolymer having a molecular weight of 5,000-20,000 and a hydroxyl content of 1.5-2.8% by wt. and (B) 20-30% of an organic polyisocyanate. In the examples copolymers are formed from styrene, n-butyl acrylate and acrylic acid as monomers. Reaction is effected in xylene with di-tert butyl peroxide and dodecyl mercaptan. To the polymer solution is added a solution in xylene/ethylene glycol monoethyl ether of the reaction product of toluylene diisocyanate and trimethylolpropane, or the reaction product of hexamethylene diisocyanate and water, titanium dioxide and optionally zinc chromate, talc, barium sulphate and calcium naphthenate. The lacquers are sprayed onto metal sheets and air dried at room temperature.</p> |
