Patents by Inventor Claudia Kräh

Claudia Kräh has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6903197
    Abstract: Azoxy dyes of the general formula I in the form of the free acid where n is 0 or 1, each R1 is selected from the group consisting of methoxy, hydroxyl and carboxyl, each R2 is selected from the group consisting of carboxyl, amino, C1-C4-alkylamino, allylamino, benzylamino and methoxycarbonylmethylamino, and the phenyl rings A may additionally be substituted by C1-C8-alkyl, unsubstituted or methyl- or halogen-substituted phenyl, hydroxyl, amino, nitro, halogen, carboxyl, N-benzylcarbamoyl, unsubstituted or nitro-, halogen-, C1-C4-alkoxy- or acetoxy-substituted phenylcarbamoyl and naphthylcarbamoyl or be benzofused, their copper complexes, a process for preparing the copper complex dyes, azoxy dyes of the formula I in their partially or completely deacylated form, their copper complexes, colorants comprising these azoxy dyes and/or their copper complexes and also their use for dyeing and printing natural or synthetic substrates.
    Type: Grant
    Filed: March 9, 2004
    Date of Patent: June 7, 2005
    Assignee: BASF Aktiengesellschaft
    Inventors: Rainer Tresch, Karl-Heinz Etzbach, Rüdiger Sens, Claudia Kräh
  • Patent number: 6727351
    Abstract: Azoxy dyes of the general formula I in the form of the free acid where n is 0 or 1, each R1 is selected from the group consisting of methoxy, hydroxyl and carboxyl, each R2 is selected from the group consisting of carboxyl, amino, C1-C4-alkylamino, allylamino, benzylamino and methoxycarbonylmethylamino, and the phenyl rings A may additionally be substituted by C1-C8-alkyl, unsubstituted or methyl- or halogen-substituted phenyl, hydroxyl, amino, nitro, halogen, carboxyl, N-benzylcarbamoyl, unsubstituted or nitro-, halogen-, C1-C4-alkoxy- or acetoxy-substituted phenylcarbamoyl and naphthylcarbamoyl or be benzofused, their copper complexes, a process for preparing the copper complex dyes, azoxy dyes of the formula I in their partially or completely deacylated form, their copper complexes, colorants comprising these azoxy dyes and/or their copper complexes and also their use for dyeing and printing natural or synthetic substrates.
    Type: Grant
    Filed: September 13, 2001
    Date of Patent: April 27, 2004
    Assignee: BASF Aktiengesellschaft
    Inventors: Rainer Tresch, Karl-Heinz Etzbach, Rüdiger Sens, Claudia Kräh
  • Patent number: 6616712
    Abstract: Compositions comprising as components A) at least one bisazo compound selected from the group consisting of the compounds of the general formula Ia  and of the general formula Ib  where R1 is C1-C8-alkyl, R2 is C2-C8-alkyl, R3 and R3′ are each C2-C21-alkyl in which up to four CH2 groups of the carbon chain may be replaced by oxygen in ether function, R4 is hydrogen or is R3 (independently of R3), R4′ is hydrogen or is R3′ (independently of R3′), B) at least one solvent in which said component A) is soluble, and optionally C) at least one surface-active substance, are useful as dye penetrants for detecting surface cracks or other defects in workpieces to be tested in this respect.
    Type: Grant
    Filed: May 17, 2001
    Date of Patent: September 9, 2003
    Assignee: BASF Aktiengesellschaft
    Inventors: Karin Heidrun Beck, Christos Vamvakaris, Karl-Heinz Etzbach, Gerhard Scholz, Claudia Kräh
  • Patent number: 6302924
    Abstract: Dye mixtures comprising one or more thienyl- and/or thiazole-azo dyes with a coupling component of the aminothiazole, aniline or tetrahydroquinoline series, one or more dyes of the class of the monoazo or disazo dyes, methine dyes, azamethine dyes, anthraquinone dyes, nitro dyes or quinophthalone dyes which have their respective absorption maximum at a wavelength of from 410 to 520 nm and optionally one or more dyes of the class of the monoazo or disazo dyes, methine dyes, azamethine dyes, anthraquinone dyes, nitro dyes or quinophthalone dyes which have their respective absorption maximum at a wavelength of from 600 to 700 nm, the FWHM value of the absorption maximum being at least 2000 cm−1, are useful for thermal transfer and for dyeing or printing synthetic materials.
    Type: Grant
    Filed: September 22, 1998
    Date of Patent: October 16, 2001
    Assignee: Basf Aktiengesellschaft
    Inventors: Karl-Heinz Etzbach, Rüdiger Sens, Claudia Kräh, Frank Wüthner
  • Patent number: 5410053
    Abstract: There are described rhodamine derivatives of the formula ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each hydrogen or substituted or unsubstituted C.sub.1 -C.sub.4 -alkyl, or R.sup.2 is paired off with R.sup.5 or R.sup.4 with R.sup.6 to form 1,3-propylene, which can be substituted,R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are each hydrogen or methyl,R.sup.9 is hydrogen, substituted or unsubstituted C.sub.1 -C.sub.4 -alkyl or a radical of the formula (C.sub.2 H.sub.4 O--).sub.n H, where n is 2 or 3, andAn.sup..crclbar. is the equivalent of an anion derived from an addition or condensation polymer that contains acid groups, novel cyclic rhodamine dyes, and the use of the novel rhodamine derivatives and cyclic rhodamine dyes for dyeing polyacrylonitrile fibers, for incorporation into polymers or for preparing inks.
    Type: Grant
    Filed: March 16, 1994
    Date of Patent: April 25, 1995
    Assignee: BASF Aktiengesellschaft
    Inventors: Erwin Hahn, Claudia Kraeh, Udo Mayer, Bernhard Albert, Walter Denzinger