Patents by Inventor Helga Sikora

Helga Sikora 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: 4559292
    Abstract: The present invention relates to a photosensitive transfer material, which comprises a flexible temporary support film which is preferably transparent, a thermoplastic photosensitive layer, optionally a flexible cover film on the free side of the photosensitive layer and, optionally, an intermediate layer between the support film and the photosensitive layer. The photosensitive transfer material is suitable for manufacturing photoresist stencils and solder masks. The temporary support film has a rough surface which exerts an embossing effect on the surface of the photosensitive layer and the intermediate layer, respectively. The mat-finish of the intermediate layer prevents an irregular deformation of this layer in moist air, while the mat-finish of the photosensitive layer precludes unwanted reflections.
    Type: Grant
    Filed: September 29, 1983
    Date of Patent: December 17, 1985
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Ulrich Geissler, Walter Herwig, Helga Sikora
  • Patent number: 4485166
    Abstract: A radiation-polymerizable mixture comprising a compound having at least two terminal ethylenically unsaturated groups which can form a crosslinked polymer by means of free-radical initiated addition polymerization, a polymeric binder, a radiation activatable polymerization initiator, and a compound having two epoxy groups in the molecule and a molecular weight of not more than 1,500; and a photopolymerizable copying material having a flexible transparent temporary support and a transferrable thermoplastic photopolymerizable layer comprising the above-described radiation-polymerizable mixture.
    Type: Grant
    Filed: April 7, 1982
    Date of Patent: November 27, 1984
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Walter Herwig, Rudolf Decker, Helga Sikora, Kurt Erbes
  • Patent number: 4399239
    Abstract: A polyurethane corresponding to the formula: ##STR1## wherein Q is a divalent, mononuclear or dinuclear aromatic radial which is unsubstituted or is substituted by lower alkyl groups and which can contain, as a linking member, a lower alkylene group,X is one of the groups --O--Ph--Z--Ph--O-- and --OOC--(CH.sub.2).sub.y --COO--,Ph being an optionally substituted phenylene group,Z being an alkylene group having 1--4 carbon atoms andy being a number from 2 to 12,R is a hydrogen atom or a methyl group,Y is an alkylene radical having 2-6 carbon atoms,m is an integer from 4 to 50n is an integer from 1 to 6 ando is an integer from 4 to 20having the properties of thermolasts and being hardenable to give elastic products. It is suitable for use as a hardenable constituent of photopolymerizable materials.
    Type: Grant
    Filed: July 21, 1982
    Date of Patent: August 16, 1983
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Walter Herwig, Kurt Erbes, Rudolf Decker, Helga Sikora
  • Patent number: 4387139
    Abstract: A polyurethane corresponding to the formula: ##STR1## wherein Q is a divalent, mononuclear or dinuclear aromatic radial which is unsubstituted or is substituted by lower alkyl groups and which can contain, as a linking member, a lower alkylene group,X is one of the groups --O--Ph--Z--Ph--O-- and --OOC--(CH.sub.2).sub.y --COO--,Ph being an optionally substituted phenylene group,Z being an alkylene group having 1-4 carbon atoms and y being a number from 2 to 12,R is a hydrogen atom or a methyl group,Y is an alkylene radical having 2-6 carbon atoms,m is an integer from 4 to 50n is an integer from 1 to 6 ando is an integer from 4 to 20having the properties of thermoplasts and being hardenable to give elastic products. It is suitable for use as a hardenable constituent of photopolymerizable materials.
    Type: Grant
    Filed: September 15, 1981
    Date of Patent: June 7, 1983
    Assignee: KALLE, Niederlassung der Hoechst AG
    Inventors: Walter Herwig, Kurt Erbes, Rudolf Decker, Helga Sikora
  • Patent number: 4379834
    Abstract: A process and an aqueous treatment solution for cleaning copper surfaces, in particular for removing residues of photoresist layers, which residues still adhere after development to the cleared copper areas, are described. The solution contains a water-soluble aliphatic sulfonic acid having 8 to 30 carbon atoms or a water-soluble salt thereof.
    Type: Grant
    Filed: June 23, 1982
    Date of Patent: April 12, 1983
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Walter Herwig, Kurt Klupfel, Helga Sikora, Heide Sprengel