Patents by Inventor Ludwig Stein

Ludwig Stein 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: 5882736
    Abstract: A formaldehyde-free chemical bath containing a palladium salt, a nitrogenated completing agent, and formic acid or formic acid derivatives, at a pH of greater than 4 and a process of using the chemical bath for depositing on a metal surface an adhesive, permanently glossy, bright palladium layer with few pores. The metal surface may be pretreated in a cementation palladium bath. The metal surface contains at least one of copper, nickel, and cobalt, as well as their alloys with one another and/or with phosphorus or boron.
    Type: Grant
    Filed: August 20, 1997
    Date of Patent: March 16, 1999
    Assignee: Atotech Deutschland GmbH
    Inventors: Ludwig Stein, Hartmut Mahlkow, Waltraud Strache
  • Patent number: 5019425
    Abstract: The invention concerns a process disclosed for the pre-treatment of synthetic materials (plastics), particularly polyetherimide, polycarbonate and poly(ester-co-carbonate), for the adhesive chemical metallization, involving treating the synthetic material with a quaternary base dissolved in an organic solvent.
    Type: Grant
    Filed: November 23, 1988
    Date of Patent: May 28, 1991
    Assignee: Schering Aktiengesellschaft
    Inventors: Michael Romer, Ludwig Stein
  • Patent number: 4929422
    Abstract: A process is disclosed for the adhesive metallization of synthetic materials, by means of pre-treatment of the synthetic materials and subsequent activation, as well as chemical and, if necessary, galvanic metal deposition, characterized by pre-treating the synthetic materials initially with an alkaline solution of an oxidation agent and then with a metal salt solution.
    Type: Grant
    Filed: March 14, 1988
    Date of Patent: May 29, 1990
    Assignee: Schering Aktiengesellschaft
    Inventors: Hartmut Mahlkow, Michael Romer, Gunther Rosskamp, Hubert-Matthias Seidenspinner, Ludwig Stein, Waltraud Strache
  • Patent number: 4352690
    Abstract: Stabilized aqueous, acid gold bath, containing a dicyanogold(I)-complex, a complex former, a reducing agent and customary additives, for electroless deposition of gold onto gold and metals that are more electronegative than gold, as well as alloys of these metals, containing a salt of hydroxylamine or a hydroxylamine derivative as reducing agent and a fluoride or hydrogen fluoride as stabilizer. Preferred embodiments include the use of an alkali- or ammonium dicyanoaurate(I) as dicyanogold(I)-complex; using a salt of hydroxylamine or a hydroxylamine derivative of the general formula ##STR1## in which R.sub.1 and R.sub.2 are the same or different and represent hydrogen or alkyl of 1 to 5 carbon atoms and X represents the residue of an inorganic acid, as reducing agent; using an alkali fluoride or an alkali hydrogen fluoride as stabilizer; and a pH-value less than 3, preferably from 0.5 to 2.8.
    Type: Grant
    Filed: July 17, 1980
    Date of Patent: October 5, 1982
    Assignee: Schering Aktiengesellschaft
    Inventors: Manfred Dettke, Ludwig Stein