COMPOSITE PIGMENTS

摘要

1373047 Coated silicate pigments HAMMOND LEAD PRODUCTS Inc 19 Sept 1972 [20 Sept 1971 31 Aug 1972] 43289/72 Heading C1A [Also in Divisions C3 and C4] A composite pigment comprises a finelydivided silicate coated with a hydrated, amorphous metal phosphate, phosphite, borate, borophosphate, borophosphite or chromate or mixture thereof. Specified base pigments are the silicate minerals wollastonite, talc, mica, nepheline and feldspar. The coating, which may constitute 4-65 wt. per cent of the composite, may be a salt of calcium, magnesium, strontium, barium, lead or zinc. The composite pigment may be made by (1) introducing into an aqueous suspension of the silicate, a metal compound capable of forming the coating pigment (e.g. a basic salt); (2) adding at least one reagent to form the coating pigment (e.g. phosphoric, boric or phosphorous acid; (3) attriting the suspension of silicate and coating pigment. Preparations are described (see Division C1). Examples 11-18 describe pigments of calcium phosphitewollastonite, barium borate-wollastonite, zinc phosphate-wollastonite, strontium chromatenepheline, lead borate-wollastonite, magnesium borophosphate/zinc borophosphate - feldspar, barium phosphate/zinc phosphate-wollastonite/ nepheline, and calcium borophosphite(lead borophosphite-wollastonite, nepheline. In Examples 6-10, calcium salt-coated wollastonite, mica or talc pigments are incorporated into paints based on linseed oil and/or soya alkyl solution and comprising solvents, metallic salt driers, and additional pigments i.e. iron oxide, zinc oxide, titanium dioxide, talc, silica, mica.