Patents by Inventor Hans-Wilhelm Engels

Hans-Wilhelm Engels 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: 6534675
    Abstract: Zinc dithiocarbamates are obtained in especially readily filterable form and high purity when zinc salts are first added, in aqueous solution, to the secondary amines underlying the zinc carbamates, so that a zinc salt complex of the amines is formed, and carbon disulfide and then sodium hydroxide solution are then introduced, with stirring, into the aqueous suspension so obtained, the temperatures being maintained in the range from room temperature to the boiling temperature of carbon disulfide until the reaction has completely finished.
    Type: Grant
    Filed: April 2, 2001
    Date of Patent: March 18, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: RĂ¼diger Schubart, Hans-Wilhelm Engels
  • Publication number: 20010039339
    Abstract: Zinc dithiocarbamates are obtained in especially readily filterable form and high purity when zinc salts are first added, in aqueous solution, to the secondary amines underlying the zinc carbamates, so that a zinc salt complex of the amines is formed, and carbon disulfide and then sodium hydroxide solution are then introduced, with stirring, into the aqueous suspension so obtained, the temperatures being maintained in the range from room temperature to the boiling temperature of carbon disulfide until the reaction has completely finished.
    Type: Application
    Filed: April 2, 2001
    Publication date: November 8, 2001
    Inventors: Rudiger Schubart, Hans-Wilhelm Engels
  • Patent number: 6140427
    Abstract: New vulcanization accelerators, corresponding to the formula ##STR1## are particularly suitable for the production of vulcanized rubbers modified with lateral polar groups.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: October 31, 2000
    Assignee: Bayer AG
    Inventors: Thomas Scholl, Hermann-Josef Weidenhaupt, Stefan Kelbch, Hans-Wilhelm Engels
  • Patent number: 5416167
    Abstract: Vulcanizable rubber compositions are disclosed which contain partial polycarboxylic acid esters or their salts. Vulcanizates obtained from the compositions are readily processible and are found to have reduced compression set and high tension values, in particular after ageing by heat.
    Type: Grant
    Filed: May 3, 1994
    Date of Patent: May 16, 1995
    Assignee: Bayer Aktiengesellschaft
    Inventors: Joachim Thormer, Thomas Scholl, Hans-Wilhelm Engels
  • Patent number: 5175349
    Abstract: The present invention relates to the use of nucleus-substituted 4-hydroxyphenyl propionic acid compounds for stabilizing organic polyisocyanates.
    Type: Grant
    Filed: March 1, 1991
    Date of Patent: December 29, 1992
    Assignee: Bayer Aktiengesellschaft
    Inventors: Pramod Gupta, Christian Konig, Hans-Jurgen Rabe, Hans-Wilhelm Engels, Wilfried Nolte, Chiraranjan Podder
  • Patent number: 5130363
    Abstract: The rubber vulcanizates according to the invention, which are produced using certain carboxyalkyl oligosulfides, are distinguished by improved hysteresis behavior; their mechanical properties remain substantially unaffected.
    Type: Grant
    Filed: November 18, 1991
    Date of Patent: July 14, 1992
    Assignee: Bayer Aktiengesellschaft
    Inventors: Thomas Scholl, Hans-Wilhelm Engels, Ulrich Eisele, Ulrich Eholzer
  • Patent number: 5124408
    Abstract: Rubber mixtures containing so-called "pre-crosslinked" polychloroprene give vulcanizates having an improved combination of low rolling resistance and low abrasion.
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: June 23, 1992
    Assignee: Bayer AG
    Inventors: Hans-Wilhelm Engels, Ulrich Eisele, Werner Obrecht, Peter Wendling, Bernd Stollfuss
  • Patent number: 5028729
    Abstract: The elminination of sulfur from bis-(dialkoxythiophosphoryl)-tetrasulfides to bis-(dialkoxythiophosphoryl)-trisulfides on certain silicate fillers, carbon black and aluminium oxide is quantitative.
    Type: Grant
    Filed: February 2, 1990
    Date of Patent: July 2, 1991
    Assignee: Bayer Aktiengesellschaft
    Inventors: Rudiger Schubart, Hans-Wilhelm Engels
  • Patent number: 5006599
    Abstract: The present invention relates to a method for stabilizing a polyether polyol having a molecular weight of from about 300 to about 10,000 comprising adding 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid as an antioxidant stabilizer, optionally in combination with other antioxidants, to said polyether polyol. This invention further relates to polyols stabilized by the method of this invention and to stabilized polyurethanes prepared from such stabilized polyols.
    Type: Grant
    Filed: December 14, 1989
    Date of Patent: April 9, 1991
    Assignee: Bayer Aktiengesellschaft
    Inventors: Pramod Gupta, Hans-Wilhelm Engels, Hansjurgen Rabe
  • Patent number: 4822845
    Abstract: It now has been found that uncured rubber composition comprising rubbers having an unsaturated carbon chain and at least one carbon black can be improved by including therein, a minor property-improving amount of at least one aromatic heterocyclic di-N-oxide compound of the partial formula ##STR1## wherein the depicted carbon atoms are part of an optionally substituted aromatic ring, and R.sup.1 and R.sup.2 are each independently hydrogen, hydrocarbyl, halohydrocarbyl, hydrocarbyloxy, hydrocarbyl sulfonyl, hydrocarbyl thio, hydrocarbylsulfoxidyl, halogen, amino,--CN--OH--CHO--CH(O hydrocarbyl)2--C(O)R.sup.3--C(O)OR.sup.3--C(N--OH)R.sup.3--C(O)NR.sup.3 R.sup.6--CH.dbd.N--NH--C(O)OR.sup.3--CH.sub.2 OC(O)CH.sub.3--R.sup.4 YR.sup.3--C(O)NHR.sup.4 OH--C(NH)NR.sup.7 R.sup.8,or--C(O)NHN(R.sup.3).sub.2wherein each R.sup.3 is independently hydrogen or a hydrocarbyl group, R.sup.4 is a divalent hydrocarbyl group, R.sup.6 is hydrogen, hydrocarbyl, --R.sup.4 OR.sup.3, or --R.sup.4 COOR.sup.3 ; R.sup.
    Type: Grant
    Filed: April 13, 1987
    Date of Patent: April 18, 1989
    Assignee: The Firestone Tire & Rubber & Company
    Inventors: Daniel F. Graves, Hans-Wilhelm Engels
  • Patent number: 4762870
    Abstract: It now has been found that the properties of rubber compositions comprising rubbers having an unsaturated carbon chain can be improved by including therein, a minor property-improving amount of at least one hydroxy-benzimidazole oxide compound of the formula ##STR1## wherein R is hydrogen, or a halogen, hydroxyl, lower acyl, lower hydrocarbyl, lower hydrocarbyloxy, lower hydrocarbylthio, carboxyl, cyano, amino, amide or --C(O)-- lower hydrocarbyl group, and R' is hydrogen, or a lower hydrocarbyl, lower hydrocarbyl amide, carboxamide carboxy acid, carboxy ester, or aryl group. When vulcanizates are prepared from such rubber compositions containing one or more fillers, the vulcanizates exhibit reduced low strain hysteresis and a high electrical resistivity.
    Type: Grant
    Filed: April 13, 1987
    Date of Patent: August 9, 1988
    Assignee: The Firestone Tire & Rubber Company
    Inventors: Daniel F. Graves, Hans-Wilhelm Engels
  • Patent number: 4761446
    Abstract: It now has been found that the properties of filled rubber compositions comprising rubbers having an unsaturated carbon chain can be improved by including therein, a minor property-improving amount of at least one 1,3-dihydroxy-benzimidazolinone or derivative compound of the formula ##STR1## wherein R is hydrogen, or a halogen, hydroxyl, lower hydrocarbyl, lower hydrocarbyloxy, lower hydrocarbylthio, lower hydrocarbyl nitrile, carboxyl, cyano, nitro, amino, amide or --C(O)--R'" where R'" is an aryl or a lower hydrocarbyl group; each R' independently is H, lower alkyl, acyl, CONR"2 or CONHR" where R" is alkyl or aryl. When vulcanizates are prepared from such uncured rubber compositions, the vulcanizates exhibit reduced low strain hysteresis and a high electrical resistivity.
    Type: Grant
    Filed: April 13, 1987
    Date of Patent: August 2, 1988
    Assignee: The Firestone Tire & Rubber Company
    Inventors: Daniel F. Graves, Hans-Wilhelm Engels