Merck Patent Gesellschaft MIT Beschrankter Haftung

E. Merck A. G.

Wilhelm Baumer

Karlheinz Neisius

Jorg Ohngemach

Horst Bernhard

Reiner Esselborn

Otto Stahlecker

Karl H Neisius

Dieter Schmitt

Fritz Zureda

An etching medium for chromed surfaces, comprises amounts of aluminum chloride, hydrochloric acid and an inorganic reducing agent, effective for etching a chromed surface. This medium is particularly advantageous when used for the correction of chromed gravure cylinders.

Etching medium and process for the correction of chromed gravure

Pigmented substantially crack-free casein plastic compositions containing a minor, luster-imparting quantity of coated mica platelets, wherein at least 75% of the pigment particles possess an average platelet size of below 10 .mu.m., a thickness of about 0.1 to 0.7 .mu.m. and a ratio of diameter to thickness of about 10 to 200.

Lustrous pigments for pigmenting casein plastics

Hardened photolacquer on semi-conductors and integrated circuits for etching purposes are stripped therefrom employing, preferably at a temperature above 75.degree. C., a stripping composition consisting essentially of 20-50 weight percent of at least one alkylbenzenesulfonic acid of 12-20 carbon, and 80-50 weight percent of a chlorine-free, aromatic hydrocarbon having a boiling point above 150.degree. C.

Method for stripping photolacquers

In indicators comprising a carrier such as cellulose saturated with one or more azo dyes having reactive groups capable of forming a chemical bond with the carrier material, the improvement wherein the indicator is made non-bleeding by using such dyes which, in addition to the reactive group, contain at least one additional sulfonic acid and/or carboxylic acid group, an example of such a dye being 4-anilino-3'-(2-hydroxysulfonyloxyethylsulfonyl)-azobenzene-6'-carboxylic acid.

Non-bleeding indicator and dyes therefor

In colorimetric indicators comprising a carrier such as cellulose saturated with one or more azo dyes having reactive groups capable of forming a chemical bond with the carrier material, the improvement wherein the indicator is made non-bleeding by using such dyes which, in addition to the reactive group, contain at least one additional sulfonic acid and/or carboxylic acid group, an example of such a dye being 4-anilino-3'-(2-hydroxysulfonyloxyethylsulfonyl)-azobenzene-6'-carboxylic acid.

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Darmstadt, Germany

Wilhelm Baumer