Patents by Inventor David C. Molzahn

David C. Molzahn 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: 4996363
    Abstract: A process for reforming alkyleneamines to predominantly linearly-extended polyalkylenepolyamines comprising contacting an alkyleneamine or mixture thereof with a catalyst under conditions such that a mixture of polyalkylenepolyamines enriched in linearly-extended products is formed, said catalyst containing at least one compound selected from the group consisting of (a) Group VB metal oxides, (b) Group VB metal phosphates, (c) silicates of Groups IIA, IIIB, IVB, VB, and the lanthanide and actinide metals, and (d) tungsten oxides, with the proviso that the silicates and tungsten oxides are essentially free of aluminum. For example, ethylenediamine is contacted with a catalyst of niobium phosphate or niobic acid under reaction conditions to yield predominantly non-cyclic polyethylenepolyamines.
    Type: Grant
    Filed: December 20, 1988
    Date of Patent: February 26, 1991
    Assignee: The Dow Chemical Company
    Inventors: Robert G. Bowman, David C. Molzahn, George E. Hartwell
  • Patent number: 4983735
    Abstract: A process for preparing alcohol-extended and amine-extended piperazines comprising contacting a difunctional aliphatic alcohol with a reactant amine, wherein at least one of the aliphatic alcohol or the reactant amine contains a piperazine moiety, in the presence of a catalyst containing a tungsten heteropoly acid. For example, monoethanolamine reacts with piperazine in the presence of a 12-tungstophosphoric acid catalyst to yield predominantly N-(2-aminoethyl)piperazine, which is an amine-extended piperazine.
    Type: Grant
    Filed: July 20, 1988
    Date of Patent: January 8, 1991
    Assignee: The Dow Chemical Company
    Inventors: George E. Hartwell, Robert G. Bowman, David C. Molzahn
  • Patent number: 4927931
    Abstract: A process for preparing alkyl-extended, alcohol-extended or amine-extended piperazines or mixtures thereof comprising contacting a difunctional aliphatic alcohol with a reactant amine, wherein at least one of the aliphatic alcohol or the reactant amine contains a piperazine moiety, in the presence of a catalyst containing a Group VB metal oxide or a Group VB metal phosphate, or mixtures thereof. For example, monoethanolamine reacts with piperazine in the presence of a catalyst of niobic acid supported on hydrated alumina to yield predominantly N-(2-aminoethyl)piperazine. Also, N-hydroxyethylpiperazine reacts with piperazine in the presence of a catalyst of niobium phosphate to yield predominantly 1,2-bis(piperazinyl)ethane.
    Type: Grant
    Filed: November 1, 1988
    Date of Patent: May 22, 1990
    Assignee: The Dow Chemical Company
    Inventors: David C. Molzahn, George E. Hartwell, Robert G. Bowman
  • Patent number: 4839460
    Abstract: A process for the preparation of novel polymers comprises reacting a primary polyether polyamine of the formulaA(E.sub.p NH.sub.2).sub.m,wherein A is the residue of a polyether initiator having m initiator groups, E is an ether moiety from an oxirane compound, p is 5-90 and m is 2-8; with an aqueous solution of formaldehyde or with paraformaldehyde in the absence of a diluent.
    Type: Grant
    Filed: February 25, 1988
    Date of Patent: June 13, 1989
    Assignee: The Dow Chemical Company
    Inventor: David C. Molzahn