Ciba Specialty Chemicals Corporation

Basf Se Corporation

Colin Dennis Campbell

Yingxia He

Damien Thurber Cole

Gordian Schilling

Rhonda Carter

Kevin Rodney Gerzevske

James Will

Joseph E Sarver

Harold Raymond Taylor, Iii

Melissa Wagner

A method for laser marking a substrate which method comprises exposing a composition comprising a tetrabenzodiazadiketoperylene pigment to laser radiation to produce a fluorescent marking readily apparent under UV light is disclosed. Many of the tetrabenzodiazadiketoperylenes herein are novel. This method can yield fluorescent markings which are not readily apparent under ambient light. A method for producing non-fluorescent laser marked substrates containing tetrabenzodiazadiketoperylene dyes is also disclosed.

Tetrabenzodiazadiketoperylene pigments for laser marking

The invention is directed to a method or use of 2,9-dichloro-quinacridone as an alpha crystal phase inhibitor and optionally, 4,11-dichloroquinacridone during the beta-quinacridone or gamma-quinacridone crude pigment particle size reduction processes. The invention is also directed to solid solutions of quinacridone comprising about 98 to about 80 weight % gamma or beta-quinacridone, about 0.1 to about 10 weight % 2,9-dichloroquinacridone and about 0.1 to about 10 weight % 4,11-dichloroquinacridone.

2,9-dichloro-quinacridone as &#x3b1;-quinacridone crystal phase inhibitor

The present invention is directed to an aqueous process for reducing particle size of organic pigments by milling the crude pigment in the presence of a water soluble styrene copolymer dispersant, optionally a defoamer, optionally an additive, and greater than about 10 wt. % water, and isolating the organic pigment.

Process for aqueous milling of quinacridone pigments

The invention is directed to a method or use of 2,9-dichloro-quinacridone as a crystal phase inhibitor during the beta-quinacridone or gamma-quinacridone crude pigment particle size reduction processes. 2,9-dichloroquinacridone is added to the milling composition of the crude gamma or crude beta quinacridone.

2,9-Dichloro-quinacridone as alpha-quinacridone crystal phase inhibitor

Dialkyl succinylsuccinates are prepared in a pure form and in high yield by reacting an alkali metal alcoholate with an excess of dialkyl succinate under anhydrous conditions followed by isolation of the di(alkali metal) salt of the dialkyl succinylsuccinate and then neutralization of the salt with acid. The resulting dialkyl succinylsuccinate is isolated or used without isolation as an intermediate in the production of quinacridone pigments. The disclosed process provides for high yields and reduced organic waste compared with known processes.

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Claymont, DE, United States of America

Colin Dennis Campbell