Ppg Industries, Inc.

Jonathan G Lasch

Charles R Wiedrich

Robert B Simmons

Charles H Hoelscher

Ronald L Haynes

Described is particulate halogen-containing material, e.g., calcium hypochlorite, containing from about 0.1 to about 10 weight percent of colorant-treated particulate inorganic water soluble salt, e.g., sodium chloride. The colorant used with the sodium chloride salt is resistant to oxidation by the halogen specie in the material and is water dispersible. The amount of colorant used is from about 0.01 to about 5 weight percent, based on the inorganic salt. Preferred are the water dispersible phthalocyanine colorants.

Solid halogen-containing composition and method for producing same

Described is photochromic particulate material comprising a photochromic substance within a matrix of a polymerizate of a polyfunctional acrylate monomer. The photochromic particulate material may be produced by adding an organic photochromic substance to a polymerizable composition including a polyfunctional acrylate monomer and polymerizing the resultant admixture, e.g., by emulsion polymerization. In the case of emulsion or suspension polymerization, finely divided particulate organic photochromic materials are separated from the polymerization medium in the form of spheroidal thermoset photochromic particles of fairly uniform size. If desired, the particles recovered from the polymerization medium may be further ground in conventional attrition mills to further reduce the size of the particulate product. In the case of bulk polymerization, the polymerizate may be formed as a continuously cast sheet, which is then pulverized to a particulate material of pigmentary size.

Growing community of inventors

Akron, OH, United States of America

Jonathan G Lasch