Patents by Inventor Sigberg Pfohl

Sigberg Pfohl 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: 5131981
    Abstract: The wet-end coloring of paper with pigments and fixers is carried out by a process in which the pigment and fixer are added simultaneously to the paper pulp to be colored, and the fixer used is a cationic fixer, in an amount of from 0.01 to 3% by weight, based on the dry paper pulp to be colored.
    Type: Grant
    Filed: June 6, 1991
    Date of Patent: July 21, 1992
    Assignee: BASF Aktiengesellschaft
    Inventors: Erwin Hahn, Georg Henning, Manfred Mielke, Hans-Juergen Degen, Sigberg Pfohl
  • Patent number: 4978427
    Abstract: Water-soluble copolymers containing copolymerized vinylamine units are prepared by copolymerizing (a) from 95 to 10 mol % of N-vinylformamide and (b) from 5 to 90 mol % of an ethylenically unsaturated monomer from the group consisting of vinyl acetate, vinyl propionate, C.sub.1 -C.sub.4 -alkyl vinyl ethers, the esters, nitriles and amines of acrylic acid and methacrylic acid and N-vinylpyrrolidone, and then eliminating from 30 to 100 mol % of the formyl groups from the copolymer. Preferred copolymers are copolymers of N-vinyl-formamide and vinyl acetate, in which from 30 to 100 mol % of the monomer units are hydrolyzed. The copolymers are used in papermaking to increase the dry strength and wet strength of the paper.
    Type: Grant
    Filed: September 5, 1989
    Date of Patent: December 18, 1990
    Assignee: BASF Aktiengesellschaft
    Inventors: Sigberg Pfohl, Michael Kroener, Heinrich Hartmann, Walter Denzinger
  • Patent number: 4880497
    Abstract: Water-soluble copolymers containing copolymerized vinylamine units are prepared by copolymerizing (a) from 95 to 10 mol % of N-vinylformamide and (b) from 5 to 90 mol % of an ethylenically unsaturated monomer from the group consisting of vinyl acetate, vinyl propionate, C.sub.1 -C.sub.4 -alkyl vinyl ethers, the esters, nitriles and amides of acrylic acid and methacrylic acid and N-vinylpyrrolidone, and then eliminating from 30 to 100 mol % of the formyl groups from the copolymer. Preferred copolymers are copolymers of N-vinylformamide and vinyl acetate, in which from 30 to 100 mol % of the monomer units are hydrolyzed. The copolymers are used in papermaking to increase the dry strength and wet strength of the paper.
    Type: Grant
    Filed: April 29, 1988
    Date of Patent: November 14, 1989
    Assignee: BASF Aktiengesellschaft
    Inventors: Sigberg Pfohl, Michael Kroener, Heinrich Hartmann, Walter Denzinger
  • Patent number: 4818341
    Abstract: Paper and paperboard of high dry strength are produced by adding a dry strength enhancer to the paper stock and dewatering the paper stock with sheet formation by using as the dry strength enhancer a mixture of a cationic polymer which contains as characteristic monomers copolymerized units of(a) diallyldimethylammonium chloride,(b) N-vinylamine or(c) a substituted or unsubstituted N-vinylimidazoline and has a K value of not less than 30, and natural potato starch which is converted into a water-soluble form by heating in an aqueous medium at above the gelatinization temperature of natural potato starch in the absence of any oxidizing agents or alkali.
    Type: Grant
    Filed: February 12, 1988
    Date of Patent: April 4, 1989
    Assignee: BASF Aktiengesellschaft
    Inventors: Hans-Juergen Degen, Sigberg Pfohl, Volkmar Weberndoerfer, Gerd Rehmer, Michael Kroener, Andreas Stange
  • Patent number: 4804387
    Abstract: Aqueous dye mixtures for black shades containing as dyes essentially those dyes which have the C.I. number 19,140, 40,000 or 47,035, in the form of the alkanolammonium salt, and also the dyes of the formula I, II and/or III ##STR1## where the cations R.sup.+ are each independently of the others an alkanolammonium cation, a substituted or unsubstituted ammonium cation or an alkali metal cation, and the quantities of the individual dyes are such as to produce a black, are suitable in particular for dyeing paper and leather.
    Type: Grant
    Filed: November 27, 1987
    Date of Patent: February 14, 1989
    Assignee: BASF Aktiengesellschaft
    Inventors: Hans-Juergen Degen, Rudolf Bermes, Sigberg Pfohl
  • Patent number: 4784724
    Abstract: Paper having a high dry strength is made using water-soluble homopolymers of salts or quaternary 1-vinyl-2-imidazolines and copolymers of these salts or quaternary compounds with acrylamide and/or methacrylamide as agents for increasing the dry strength of paper.
    Type: Grant
    Filed: April 15, 1986
    Date of Patent: November 15, 1988
    Assignee: BASF Aktiengesellschaft
    Inventors: Sigberg Pfohl, Volkmar Weberndoerfer, Heinrich Hartmann, Friedrich Linhart
  • Patent number: 4774285
    Abstract: Water-soluble copolymers containing copolymerized vinylamine units are prepared by copolymerizing (a) from 95 to 10 mol % of N-vinylformamide and (b) from 5 to 90 mol % of an ethylenically unsaturated monomer from the group consisting of vinyl acetate, vinyl propionate, C.sub.1 -C.sub.4 -alkyl vinyl ethers, the esters, nitriles and amides of acrylic acid and methacrylic acid and N-vinylpyrrolidone, and then eliminating from 30 to 100 mol % of the formyl groups from the copolymer. Preferred copolymers are copolymers of N-vinylformamide and vinyl acetate, in which from 30 to 100 mol % of the monomer units are hydrolyzed. The copolymers are used in papermaking to increase the dry strength and wet strength of the paper.
    Type: Grant
    Filed: September 15, 1986
    Date of Patent: September 27, 1988
    Assignee: BASF Aktiengesellschaft
    Inventors: Sigberg Pfohl, Michael Kroener, Heinrich Hartmann, Walter Denzinger
  • Patent number: 4294873
    Abstract: A process for the manufacture of paper having a high dry strength and a low wet strength, by treating the surface of the paper with an aqueous solution of an alkali metal and/or alkaline earth metal salt of a polymer of (a) from 91 to 100% by weight of acrylic acid and/or methacrylic acid and (b) from 0 to 9% by weight of acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, vinyl acetate, maleic anhydride, diisobutylene, an ester of acrylic acid and/or an ester of methacrylic acid, which has a viscosity of from 5 to 100 mPas in 2% strength aqueous solution at 20.degree. C., and drying the impregnated paper. The polymer is generally employed in an amount of from 1 to 4% by weight, based on dry paper, and increases the dry strength of the paper without substantially increasing the wet strength.
    Type: Grant
    Filed: January 3, 1980
    Date of Patent: October 13, 1981
    Assignee: BASF Aktiengesellschaft
    Inventors: Juergen Hartmann, Joachim Stedefeder, Walter Denzinger, Sigberg Pfohl
  • Patent number: 4191692
    Abstract: In the manufacture of tocopherol (vitamin E) by reaction of isophytol with trimethylhydroquinone in the presence of zinc chloride and acid in a hydrocarbon solvent one of the starting compounds, isophytol, is pretreated with small amounts of ammonia or an amine.Tocopherol is obtained in higher yield and purity.
    Type: Grant
    Filed: April 14, 1978
    Date of Patent: March 4, 1980
    Assignee: BASF Aktiengesellschaft
    Inventors: Paul Grafen, Henning Kroesche, Bernhard Schulz, Joachim Paust, Sigberg Pfohl
  • Patent number: 4081477
    Abstract: Pinanes substituted by a group X in the 3-position which group is formyl, or its alkyl-acetals or alkyl-hemiacetals, carboxylic acid, carboxylic acid chloride, carboxylic acid amide, hydroxymethyl or aminomethyl substituted in a specific manner at the nitrogen, the optical isomers of these compounds and a process for their manufacture by hydroformylation of .alpha.-pinene in the presence of rhodium catalysts, and conversion of the 3-formylpinane first produced into the above derivatives by conventional methods.
    Type: Grant
    Filed: January 27, 1975
    Date of Patent: March 28, 1978
    Assignee: BASF Aktiengesellschaft
    Inventors: Werner Hoffmann, Walter Himmele, Joachim Paust, Karl Von Fraunberg, Hardo Siegel, Sigberg Pfohl
  • Patent number: 3996246
    Abstract: A process for resolving racemic .alpha.-hydroxy-.beta.,.beta.-dimethyl-.gamma.-butyrolactone, referred to as D,L-pantolactone, into its optical antipodes, based on the separation of diastereomeric salts of D,L-pantoic acid (.alpha.,.gamma.-dihydroxy-.beta.,.beta.-dimethylbutyric acid), produced from D,L-pantolactone, by means of (-)-3-aminomethylpinane, (+)-3-aminomethylpinane or one of their acid addition salts, as a new resolving agent.
    Type: Grant
    Filed: January 24, 1975
    Date of Patent: December 7, 1976
    Assignee: BASF Aktiengesellschaft
    Inventors: Werner Hoffmann, Walter Himmele, Joachim Paust, Karl Von Fraunberg, Hardo Siegel, Sigberg Pfohl