Inventor
SPIETSCHKA ERNST
43 patents
Patents
43 patentsUS4496731AJan 29, 1985
Process for the preparation of perylene-3,4,9,10-tetracarboxylic acid N,N'-d
HOECHST AG30 citations93
US4431806AFeb 14, 1984
Process for the preparation of pigments of the perylene-3,4,9,10-tetracarboxylic acid diimide series, and their use
HOECHST AG28 citations93
US4714666ADec 22, 1987
Perylene tetracarboxylic acid imide pigments in an electrophotographic recording material
HOECHST AG37 citations92
US4709029ANov 24, 1987
Process for the preparation of perylene-3,4,9,10-tetracarboxylic acid monoanhydride monoimides
HOECHST AG32 citations92
US4599408AJul 8, 1986
Perylene-3,4,9,10-tetracarboxylic acid monoanhydride monoimides
HOECHST AG27 citations92
US4253839AMar 3, 1981
Process for the fine distribution of pigments of the dioxazine series
HOECHST AG34 citations92
US4501906AFeb 26, 1985
Monoalkali metal salts of perylene-3,4,9,10-tetracarboxylic acid monoanhydride and process for their manufacturing
HOECHST AG24 citations82
US4116923ASep 26, 1978
Dyed polyesters, process for their preparation and their use for the dyeing of plastics
HOECHST AG24 citations80
US4797162AJan 10, 1989
Process for the preparation of perylene-3,4,9,10-tetracarboxylic acid N,N'-d
HOECHST AG11 citations74
US4705572ANov 10, 1987
Process for the preparation of pigments of the anthanthrone series
HOECHST AG14 citations74
US4655845AApr 7, 1987
Process for preparing organic pigments having excellent application properties
HOECHST AG10 citations74
US4588814AMay 13, 1986
Process for the preparation of 3,4,9,10-perylenetetracarboxylic acid diimide
HOECHST AG10 citations74
US5154770AOct 13, 1992
Mix-crystal pigments based on perylenetetracarbimides, process for their preparation and their use
HOECHST AG13 citations73
US4831140AMay 16, 1989
Process for the preparation of arylimides of perylene-3,4,9,10-tetracarboxylic acid
HOECHST AG16 citations73
US4769460ASep 6, 1988
Mix-crystal pigments based on perylenetetracarbimides, process for preparing and their use
HOECHST AG9 citations73
US4758665AJul 19, 1988
Process for preparing high-hiding gamma-modification of unsubstituted linear transquinacridone
HOECHST AG11 citations73
US4742170AMay 3, 1988
Mix-crystal pigments based on perylenetetracarbimides, process for their preparation, and their use
HOECHST AG10 citations73
US4594420AJun 10, 1986
Perylene-3,4,9,10-tetracarboxylic acid monoanhydride monoimide and monoimidazolide compounds, processes for their preparation and their use
HOECHST AG13 citations73
US4224222ASep 23, 1980
Process for preparing copper phthalocyanine pigments of the α-modification
HOECHST AG8 citations73
US4018791AApr 19, 1977
Process for the preparation of highly pure halogenated phthalocyanine pigment
HOECHST AG12 citations73
US3939093AFeb 17, 1976
Daylight fluorescent pigments
HOECHST AG9 citations73
US4732618AMar 22, 1988
Powdered pigments with improved rheological properties, processes for their preparation and their use with a content of at least 5% of unsubstituted quinacridone
HOECHST AG11 citations72
US4153602AMay 8, 1979
Process for the preparation of a N,N'-dimethyl-perylene-3,4,9,10-tetracarboxylic acid diimide pigment
HOECHST AG8 citations72
US3984433AOct 5, 1976
Process for preparing copper phthalocyanine pigments of the α-modification
HOECHST AG13 citations71
US4124768ANov 7, 1978
Process for preparing pure substituted 2,5-diarylamino-terephthalates and the corresponding free acids
HOECHST AG12 citations68
US4002642AJan 11, 1977
Process for the preparation of polyhalo copper phthalocyanines
HOECHST AG8 citations68
US4650879AMar 17, 1987
Process for the preparation of perylene-3,4,9,10-tetracarboxylic dianhydride
HOECHST AG4 citations63
US4460410AJul 17, 1984
Process for the manufacture of a perylene tetracarboxylic acid dianhydride pigment
HOECHST AG2 citations63
US4284789AAug 18, 1981
Thio-indigo dyestuffs
HOECHST AG2 citations63
US4229583AOct 21, 1980
Process for preparing thio-indigo dyestuffs
HOECHST AG3 citations63
US4599431AJul 8, 1986
Process for the preparation of naphthalene-1,4,5,8-tetracarboxylic acid and its 1,8-monoanhydride in a high degree of purity
HOECHST AG2 citations62
US4212975AJul 15, 1980
Process for the manufacture of the gamma-crystal modification of linear trans-quinacridone
HOECHST AG5 citations62
US4010180AMar 1, 1977
Process for the purification of copper phthalocyanine
HOECHST AG4 citations62
US4758664AJul 19, 1988
Process for the preparation of linear quinacridones
HOECHST AG6 citations61
US4693753ASep 15, 1987
Pigments of the quinacridonequinone series, process for their preparation and their use
HOECHST AG3 citations61
US4009180AFeb 22, 1977
Continuous process for preparing copper phthalocyanine
HOECHST AG4 citations61
US4056534ANov 1, 1977
Process for preparing copper phthalocyanine pigments of the α-modification
HOECHST AG6 citations59
US4689087AAug 25, 1987
Process for the preparation of an organic pigment on the basis of 4,4',7,7'-tetrachloro-thio-indigo
HOECHST AG1 citations52
US4617403AOct 14, 1986
Process for preparing a pigment based on 4,4',7,7'-tetrachlorothioindigo
HOECHST AG1 citations52
US4614803ASep 30, 1986
Process for the preparation of dry alkali metal salts of 1,8-naphthalimide
HOECHST AG0 citations52
US4456762AJun 26, 1984
Process for the preparation of 4,7-dichloro-3-hydroxy-thionaphthene
HOECHST AG0 citations52
US4684753AAug 4, 1987
Process for preparing 1,3,6,8-tetrabromopyrene
HOECHST AG1 citations51
US3974177AAug 10, 1976
Process for the purification of crude polyhalo copper phthalocyanines
HOECHST AG1 citations47