Patents by Inventor Druce K. Crump

Druce K. Crump 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).

  • Methylenephosphonic acid derivatives of bis(aminoalkyl)piperazines as cement set retarding agents
    Patent number: 4500356
    Abstract: Methylenephosphonic acid derivatives of bis(aminoalkyl)piperazine are employed as cement set retarding additives. The compounds must have at least one of the amine hydrogens phosphonomethylated.
    Type: Grant
    Filed: February 24, 1984
    Date of Patent: February 19, 1985
    Assignee: The Dow Chemical Company
    Inventors: Druce K. Crump, Jaime Simon, David A. Wilson
  • Metal ion control compounds based on norbornane
    Patent number: 4500469
    Abstract: The bis(methylamine) of norbornane compounds which have at least one of the amine hydrogens substituted with hydroxyalkyl, methylenephosphonic, alkylenesulfonic, carboxylic acid radicals and salts of any of the acid radicals are useful as chelating, sequestering agents. The phosphonate substituted compounds are also useful as threshold agents.
    Type: Grant
    Filed: February 27, 1984
    Date of Patent: February 19, 1985
    Assignee: The Dow Chemical Company
    Inventors: Jaime Simon, Druce K. Crump, David A. Wilson
  • Polyumeric alkylene phosphoric acid piperazine derivatives as scale inhibitors
    Patent number: 4489203
    Abstract: New polymers which are the reaction product of aminoethylpiperazine and a dihalo or epoxyhalo compound are subsequently phosphonomethylated to provide products which are useful as threshold ion control agents.
    Type: Grant
    Filed: September 27, 1982
    Date of Patent: December 18, 1984
    Assignee: The Dow Chemical Company
    Inventors: David A. Wilson, Druce K. Crump
  • New additives for retarding setting of cement from methylenephosphonated aminohydrocarbylpiperazine-urea adducts
    Patent number: 4472200
    Abstract: Certain methylenephosphonic acid derivatives of aminohydrocarbylpiperazine-urea adducts have been found to be good cement set-retarding additives.
    Type: Grant
    Filed: September 2, 1983
    Date of Patent: September 18, 1984
    Assignee: The Dow Chemical Company
    Inventors: Druce K. Crump, David A. Wilson
  • Scale control in flue gas desulfurization
    Patent number: 4469663
    Abstract: An improvement in a process for flue gas desulfurization in which particular phosphonomethylated derivatives of aminoethylpiperazine, employed as threshold agents, prevent calcium scale formation in the contacting section but permit precipitation of calcium compounds at a later stage.
    Type: Grant
    Filed: October 15, 1982
    Date of Patent: September 4, 1984
    Assignee: The Dow Chemical Company
    Inventors: Druce K. Crump, David A. Wilson, Gary D. Gatton
  • Set retarding additives for cement from aminomethylenephosphonic acid derivatives
    Patent number: 4468252
    Abstract: Compounds useful as cement set retarding additives have been found which have the formula ##STR1## wherein A, B, C and D substituents are independently selected from hydrogen, methylenephosphonic acid, or salts thereof, hydroxypropyltrialkylammonium halide, wherein the trialkylammonium moiety contains alkyl groups having from 1 to 5 carbon atoms and n is 0 to 15, and wherein said substituents include at least one methylenephosphonic acid group, or salt thereof, and at least one hydroxypropyltrialkylammonium halide group.
    Type: Grant
    Filed: June 1, 1983
    Date of Patent: August 28, 1984
    Assignee: The Dow Chemical Company
    Inventors: Druce K. Crump, David A. Wilson
  • Cement compositions containing set retarders
    Patent number: 4466835
    Abstract: The process of employing as a cement setting retarder a compound which is a derivative of dicyclopentadiene bis(methylamine) wherein at least one amine hydrogen is substituted with a methylenephosphonic acid group or a salt thereof.
    Type: Grant
    Filed: April 18, 1983
    Date of Patent: August 21, 1984
    Assignee: The Dow Chemical Company
    Inventors: Druce K. Crump, David A. Wilson
  • Set retarding compounds for use in cement slurries
    Patent number: 4466836
    Abstract: The process of employing as a cement setting retarder a compound which is a phosphonomethylated derivative of a dimer or polymer which is the reaction product of ethylene dichloride or epichlorohydrin with aminoethylpiperazine wherein at least 50% of the amine hydrogen substituents are phosphonomethyl groups or an alkali metal, alkaline earth metal or ammonium salt thereof.
    Type: Grant
    Filed: April 28, 1983
    Date of Patent: August 21, 1984
    Assignee: The Dow Chemical Company
    Inventors: Druce K. Crump, David A. Wilson
  • Preparation of a zinc chelate having improved stability
    Patent number: 4312815
    Abstract: An improved process of preparing an aqueous solution of the zinc chelate of N-(2-hydroxyethyl) iminodiacetic acid wherein ammonia is added to the aqueous solution during its preparation to increase the solubility of zinc therein.
    Type: Grant
    Filed: March 31, 1980
    Date of Patent: January 26, 1982
    Assignee: The Dow Chemical Company
    Inventors: David A. Wilson, Druce K. Crump, Freddie Griffin, Jr.