Patents by Inventor Jurgen Engelhardt

Jurgen Engelhardt 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: 6146858
    Abstract: Samples of commercial cellulose having high crystallinity (>80%) and a degree of polymerization of approximately 1500 were pretreated enzymatically under various conditions with commercial endoglucanases, before the chemical conversion to substituted cellulose derivatives was carried out. The enzymatically pretreated cellulose samples exhibited a significantly higher substitution, up to 222% higher, in comparison with control samples which had been treated with buffer without enzyme. The increase in substitution during the chemical reaction could be observed in the presence of various amounts of alkali, but fell as the amounts of alkali decreased. At the same degree of substitution of the cellulose derivative, the use of cellulose pretreated with endoglucanase significantly reduced the amount of alkali required by 60%, as compared with the use of cellulose pretreated only with buffer.
    Type: Grant
    Filed: February 14, 2000
    Date of Patent: November 14, 2000
    Assignee: Wolff Walsrode AG
    Inventors: Rainhardt Koch, Frank Berendes, John Foster, Hans-Georg Rast, Jurgen Engelhardt, Jorg Neubauer, Wolfgang Koch, Klaus Szablikowski
  • Patent number: 5861506
    Abstract: Thermoplastic and compostable cellulose ether esters with 2-hydroxycarboxylic acids as acid components and mixed esters which, in addition to 2-hydroxycarboxylic acid groups, have further mono-, dicarboxylic acid or carbamate groups.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: January 19, 1999
    Assignee: Wolff Walsrode AG
    Inventors: Joachim Simon, Hanns Peter Muller, Rainhard Koch, Dirk Jacques Dijkstra, Jurgen Engelhardt, Volkhard Muller
  • Patent number: 5717087
    Abstract: The present invention relates to thermoplastic and biodegradable polysaccharide esters/polysaccharide ether esters, which are characterised in that they can be represented by the general structure ##STR1## wherein Polysaccharide-O represents the substituted OH groups of a polymeric saccharide unit and wherein A is a linear polyether chain of the following structureA=(E--O)nwherein E signifies a linear aliphatic or aromatic branched or unbranched chain having 2 to 11 C atoms, n is an integer equal to or greater than 0 and both B and D are a maleic acid addition product of the following structure ##STR2## wherein F is an aliphatic, saturated, monounsaturated or polyunsaturated carbon skeleton, which may optionally be provided with further substituents and wherein C can be a hydrogen atom, one or more substituents from the group dihydroxyethyl, hydroxypropyl, hydroxybutyl, methyl, ethyl, benzyl, dihydroxypropyl, carboxyalkyl, sulphoalkyl or cyanoethyl.
    Type: Grant
    Filed: August 2, 1996
    Date of Patent: February 10, 1998
    Assignee: Wolff Walsrode AG
    Inventors: Jochen Kalbe, Reinhard Koch, Hanns Peter Muller, Jurgen Engelhardt, Wolfgang Koch, Volkhard Muller
  • Patent number: 5698612
    Abstract: The present invention provides thermoplastically workable and completely biodegradable moulding compositions, a process for the preparation thereof and the use thereof as biodegradable materials for the production of, for example, injection-moulded parts, films, fibres or coatings.
    Type: Grant
    Filed: December 11, 1996
    Date of Patent: December 16, 1997
    Assignee: Bayer Akteingesellschaft
    Inventors: Joachim Simon, Hanns Peter Muller, Dirk Jacques Dijkstra, Jurgen Engelhardt, Volkhard Muller, Gunter Weber
  • Patent number: 5639865
    Abstract: The present invention relates to novel thermoplastic, biodegradable polysaccharide ether esters, such as for example cellulose ether esters or starch ether esters, and to the production of such graft copolymers from polysaccharides, epoxides and dicarboxylic acid anhydrides and to the use thereof, for example as moldings, films or coatings.
    Type: Grant
    Filed: February 9, 1995
    Date of Patent: June 17, 1997
    Assignee: Wolff Walsrode Aktiengesellschaft
    Inventors: Jochen Kalbe, Hanns-Peter Muller, Rainhard Koch, Jurgen Engelhardt, Wolfgang Koch, Klaus Szablikowski, Gunter Weber
  • Patent number: 5466794
    Abstract: The present invention relates to novel thermoplastic, water-insoluble cellulose hydroxyalkyl hydroxycarboxylic acid esters of the general structureCell--O--Rwhere Cell--O is the substituted OH group of a polymeric cellulose unit and R is either a monomeric and/or polymeric hydroxyalkylether hydroxycarboxylic acid ester of the structure X:X=--A--B--in which A is a linear polyether chain:A=(--D--O--).sub.nin which D signifies a linear aliphatic branched or unbranched chain with 2 to 11 C atoms and n is a whole number equal to or greater than 1, and B is a linear polyester chain: ##STR1## in which E signifies a linear aliphatic branched or unbranched chain with 2 to 5 C atoms and m is a whole number equal to or greater than 1, or R is equal to A or B or X and a combination thereof in any ratio, or R is equal to H (hydrogen) according to the degree of substitution per anhydroglucose unit (max. 3) with A, B or X, and a process for their production and use of these cellulose derivatives as biodegradable mouldings.
    Type: Grant
    Filed: May 17, 1994
    Date of Patent: November 14, 1995
    Assignee: Wolff Walsrode Aktiengesellschaft
    Inventors: Jochen Kalbe, Hanns P. Muller, Rainhard Koch, Jurgen Engelhardt, Wolfgang Koch, Klaus Szablikowski, Gunter Weber
  • Patent number: 5134219
    Abstract: The substituted polyheterocycles containing recurring structural units corresponding to the formula ##STR1## in which X is an oxygen atom, a sulfur atom or N-H, show good solubility in mixtures of methanesulfonic acid and methylene chloride or trifluoroacetic acid and methylene chloride. They may be used for the production of mixtures with thermoplastic polymers.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: July 28, 1992
    Assignee: Bayer Aktiengesellschaft
    Inventors: Hans R. Kricheldorf, Jurgen Engelhardt, Ralf Pakull, Volker Eckhardt, Ulrich Leyrer