Patents by Inventor Karl-Heinz Lindemann

Karl-Heinz Lindemann 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: 4746411
    Abstract: Bright electrodeposits of zinc/iron alloys onto iron of good ductility and adhesion are obtained at low electroplating voltage and high current yield by using a bath containing zinc sulfate, ferrous sulfate, conductive salt, citric acid and alkali metal acetate and, as additional ingredients, saccharin, a naphthalene mono-, -di- or -trisulfonate or a condensation product thereof with formaldehyde and/or an organic complexing agent for iron and further one or more compounds selected from the group consisting of alkali metal cumene sulfonate, alkali metal benzoate, collagen hydrolyzate having a mean molecular weight of from 500 to 2000 and a reducing agent for ferric irons selected from the group consisting of alkali metal bisulfite, alkali metal dithionite and hydroxy ammonium chloride.
    Type: Grant
    Filed: May 29, 1987
    Date of Patent: May 24, 1988
    Assignee: Elektro-Brite GmbH
    Inventors: Klaus-Peter Klos, Karl-Heinz Lindemann, Hermann Donsbach
  • Patent number: 4740278
    Abstract: Bright electrodeposits of zinc/iron alloys of good ductility and adhesion are obtained at low electroplating voltage and high current yield by using a bath containing zinc chloride, ferrous chloride, conductive salt and, as additional ingredients, saccharin, a dextrin of molecular weight 2,000 to 30,000 and, optionally, a reducing agent for ferric ions such as alkali metal bisulfite, alkali metal dithionite and hydroxyl ammonium chloride at a p.sub.H 1-3.5.
    Type: Grant
    Filed: May 29, 1987
    Date of Patent: April 26, 1988
    Assignee: Elektro-Brite GmbH
    Inventors: Klaus-Peter Klos, Karl-Heinz Lindemann, Hermann Donsbach
  • Patent number: 4740277
    Abstract: Bright electrodeposits of zinc/nickel alloys onto iron of fine crystalline structure are obtained by using an acidic bath containing the sulfates of zinc and nickel, alkali metal acetate and brightening agents, the brightening agents being (1) citric acid, (2) hexin-3-diol-2,5 and (3) naphthalene sulfonic acid having 1 to 3 sulfo groups which is optionally substituted by one or two C.sub.1 -C.sub.4 -alkyl groups and halogen atoms, respectively or a condensation product thereof with formaldehyde.
    Type: Grant
    Filed: May 29, 1987
    Date of Patent: April 26, 1988
    Assignee: Elektro-Brite GmbH
    Inventors: Klaus-Peter Klos, Karl-Heinz Lindemann, Hermann Donsbach
  • Patent number: 4705576
    Abstract: An aqueous acidic trivalent chromium and fluoride containing coating (passivating) solution for zinc, zinc alloy and cadmium surfaces contains one or more complex compounds of the formula[Cr(H.sub.2 O).sub.6-x F.sub.x ].sup.(3-x)+ A.sup.-wherein x is an integer of from 1 to 3 and A is an anion of the group selected from nitrate, sulfate, phosphate, chloride, bromide, fluoride and iodide. In particular the solution contains a soluble nitrate in an amount greater than the cromium(III)concentration and before application the solution is either heated to at least 60.degree. C. or treated with a catalyst at a temperature above 15.degree. C.
    Type: Grant
    Filed: November 3, 1986
    Date of Patent: November 10, 1987
    Assignee: Elektro-Brite GmbH
    Inventors: Klaus-Peter Klos, Karl-Heinz Lindemann, Willi Birnstiel
  • Patent number: 4397717
    Abstract: A bath for electoplating zinc containing in aqueous solution a zinc salt, an alkali metal hydroxide, optionally, an aromatic aldehyde or ketone and other usual additives and, if desired, an alkali metal cyanide and further, as a brightener, one or more reaction products obtained by reacting (a) an epihalohydrin with a heterocyclic nitrogen compound containing at least two reactive nitrogen atoms which compound may be substituted by 1 or 2 methyl, ethyl or amino groups or of a mixture of such reaction products of the epihalohydrin and the nitrogen compound in a molar ratio of 1:1 with (b) ammonia, an aliphatic amine, polyamine and/or polyimine in a molar ratio of 1:0.3 to 1:1 said bath yielding highly brilliant zinc coatings which may be up to 40 .mu.m thick and are abrasion resistant and resistant to temperatures up to about 220.degree. C. in a range of current densities of from 0.5 to 5 amps/dm.sup.2.
    Type: Grant
    Filed: February 10, 1981
    Date of Patent: August 9, 1983
    Assignee: Elektro-Brite GmbH & Co. KG.
    Inventors: Simeon Acimovic, Karl-Heinz Lindemann, Volker G. Kunz
  • Patent number: 4388161
    Abstract: Bright deposits of tin and tin/lead alloys by electrocoating are obtained by using a bath containing tin salts and, optionally, lead salts, aldehydes and/or ketones as brighteners as well as surfactants besides sulfuric acid and/or borofluohydric acid wherein part or all of the aldehydes and/or ketones are replaced by a cyclic reaction product of one or more aromatic aldehydes and epihalohydrin of the general formula ##STR1## (Hal being chlorine or bromine, R being a phenyl, naphthyl or pyridyl radical which is optionally substituted by one to three members of the group consisting of chlorine, bromine or fluorine atoms, alkyl or alkoxy groups having 1 to 3 carbon atoms, carboxy and hydroxy groups). Preferably the cyclic reaction product is contained in the bath in an amount of from 0.1 to 2 g/liter of the bath.
    Type: Grant
    Filed: June 24, 1982
    Date of Patent: June 14, 1983
    Assignee: Elektro-Brite GmbH & Co. KG
    Inventors: Simeon Acimovic, Karl-Heinz Lindemann, Volker G. Kunz