Water dilutable coating compositions
AssigneeBASF Lacke + Farben, AG
InventorsRoland Treutlein, Bodo Muller, Peter Mayenfelds
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AssigneeBASF Lacke + Farben, AG
InventorsRoland Treutlein, Bodo Muller, Peter Mayenfelds
Estimating the term…
The invention relates to water-dilutable coating compositions which contain a binder, an aluminum pigment and an aqueous diluent. The water-dilutable coating compositions according to the invention are distinguished in that they contain, as the aluminum pigment, a pigment which has been obtained by passivating a lubricant-containing aluminum pigment in an aqueous passivating solution which contains chromic acid and a water-soluble glycol ether of the general formula R.sup.1 --(--O--CHR.sup.2 --CH.sub.2 --).sub.n --OH (R.sup.1 represents a lower alkyl radical, R.sup.2 represents either an H atom or a lower alkyl radical, preferably a --CH.sub.3 group, and n represents a number from 1 to 5) and/or a water-soluble glycol of the general formula HO--(CHR.sup.3 --CH.sub.2 --O--).sub.n H (R.sup.3 represents either an H atom or a lower alkyl radical, preferably a --CH.sub.3 group, and n represents a number from 1 to 5), at not less than 50.degree. C., preferably 60.degree. to 90.degree. C., particularly preferably about 80.degree. C.
A water-dilutable coating composition which contains a binder, an aqueous diluent and an aluminum pigment which has been obtained by passivating a lubricant-containing aluminum pigment in an aqueous passivating solution which contains chromic acid and a water-soluble glycol ether of the general formula R.sup.1 --(--O--CHR.sup.2 --CH.sub.2 --).sub.n --OH, wherein R.sup.1 represents a lower alkyl radical, R.sup.2 represents either an H atom or a lower alkyl radical and n represents a number from 1 to 5, or a water-soluble glycol of the general formula HO--(--CHR.sup.3 --CH.sub.2 --O--).sub.n H wherein R.sup.3 represents either an H atom or a lower alkyl radical n represents a number from 1 to 5, at not less than 50.degree. C.
A process for preparing an aluminum pigment which can be employed in water-dilutable coating compositions comprising:
A method of coating a substrate comprising applying to the substrate a water-dilutable coating composition comprised of a binder, an aqueous diluent and an aluminum pigment obtained by passivating a lubricant-containing aluminum pigment at not less than 50.degree. C. in an aqueous passivating solution containing chromic acid and a water soluble glycol ether of the formula:
Dependencies are inferred from the claim text.