Patents by Inventor Carl P. Strange

Carl P. Strange 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).

  • Process for preparing cellulose ethers
    Patent number: 4537958
    Abstract: Non-gelling cellulose ethers are purified by mixing same with a dialdehyde under acidic conditions and under high agitation, forming a slurry of the treated cellulose ether, rapidly transferring the slurry to a filter and then dewatering said slurry.
    Type: Grant
    Filed: June 29, 1984
    Date of Patent: August 27, 1985
    Assignee: The Dow Chemical Company
    Inventors: Carl P. Strange, Harold B. Martin, Jr., Albert C. Tsang
  • Process for preparing hydroxyalkylcellulose ethers
    Patent number: 4477657
    Abstract: Higher reaction efficiencies are seen in cellulose etherification reactions when the reagents are continuously added to alkali cellulose at elevated temperatures. In particular, mixed hydroxyalkylcellulose ethers are prepared with higher reaction efficiencies using this process. In an especially preferred embodiment, hydroxypropylmethylcellulose is prepared by continuously adding propylene oxide to heated cellulose containing a small amount of caustic, adding more caustic and then continuously adding methyl chloride at elevated temperatures.
    Type: Grant
    Filed: July 8, 1983
    Date of Patent: October 16, 1984
    Assignee: The Dow Chemical Company
    Inventors: Carl P. Strange, Christopher D. Messelt, Clark W. Gibson
  • Process for preparing cellulose derivatives
    Patent number: 4410693
    Abstract: Cellulose derivatives having a controlled molecular weight are prepared by adjusting oxygen concentration as measured by analyzing the quantity of oxygen in the head space of the reaction vessel to a level such that the cellulose derivative prepared therein has a desired solution viscosity. The cellulose derivative is then prepared in the reaction vessel without substantially increasing the quantity of oxygen in said reaction vessel.
    Type: Grant
    Filed: August 12, 1982
    Date of Patent: October 18, 1983
    Assignee: The Dow Chemical Company
    Inventors: Clark W. Gibson, Carl P. Strange
  • Method of preparing polysaccharide ethers and apparatus
    Patent number: 4015067
    Abstract: Polysaccharide ethers are prepared in a novel continuous process in which a slurry of a polysaccharide, an alkali metal hydroxide, and an etherifying agent, with or without an inert diluent, are mixed in the substantial absence of molecular or free oxygen and fed through a sinuous tubular reactor under pressure, so that the etherification reaction is continuous. The apparatus for preparing the reaction mixture is also novel.
    Type: Grant
    Filed: August 18, 1975
    Date of Patent: March 29, 1977
    Assignee: The Dow Chemical Company
    Inventors: Gordon Y. T. Liu, Carl P. Strange
  • Well treating composition and method
    Patent number: 3954626
    Abstract: Novel compositions comprise homogeneous mixtures of liquid carbon dioxide and an anhydrous lower alkanol gelled to a viscosity of at least 10 centipoises with a hydroxypropyl methylcellulose having a methoxyl degree of substitution of from 0.2 to 1.0 and a molar substitution of hydroxypropoxyl of at least 1.2. The compositions are employed in a method of treating a subterranean formation penetrated by a wellbore by injecting same under pressure down the wellbore and into the formation to stimulate production of natural gas or petroleum.
    Type: Grant
    Filed: September 24, 1973
    Date of Patent: May 4, 1976
    Assignee: The Dow Chemical Company
    Inventors: George K. Greminger, Jr., Carl P. Strange, Samuel A. Pence, Jr.