Patents by Inventor Raymond C. Francis

Raymond C. Francis 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).

  • Method for brightening chemical pulp with hydrogen peroxide using a magnesium compound in silicate solution
    Patent number: 6699358
    Abstract: A method for brightening chemical pulps with less than 18% lignin utilizing a magnesium compound in a sodium silicate solution to form a higher percentage of high molecular weight silicates. Such high molecular weight silicates preferentially adsorb transition metal impurities, which, if left in solution, would tend to decompose hydrogen peroxide and organic peroxides. Hydrogen peroxide is added to peroxide and peroxide/oxygen stages, while it is generated, along with organic peroxides during an oxygen stage.
    Type: Grant
    Filed: January 11, 2001
    Date of Patent: March 2, 2004
    Assignees: National Silicates Partnership, Research Foundation of State University of New York
    Inventors: Timothy D. Evans, Raymond C. Francis
  • Method for reducing thermal and light-induced brightness reversion in lignin-containing pulps
    Patent number: 5443634
    Abstract: A method and article of manufacture thereof is provided for reducing brightness reversion in bleached lignin-containing pulps or newsprint by the treatment of the bleached lignin-containing pulp or newsprint with 2,5-dihydroxydioxane. In one embodiment, calcium carbonate is added to enhance the activity of 2,5-dihydroxydioxane.
    Type: Grant
    Filed: July 28, 1994
    Date of Patent: August 22, 1995
    Assignees: The Research Foundation of the State University of New York, Minerals Technologies Inc.
    Inventors: Raymond C. Francis, Daniel B. Evans
  • Ozone/peroxymonosulfate process for delignifying a lignocellulosic material
    Patent number: 5411635
    Abstract: A process for delignifying a lignocellulosic material comprising exposing the material to a mixture of peracid and ozone. Preferred peracids include Caro's acid and peracetic acid. Also disclosed is a kraft pulp delignification mixture comprising in combination: (a) water; (b) a kraft pulp at 1-40% consistency; (c) a peracid; and (d) from 0.1 to 5.0% ozone on pulp.
    Type: Grant
    Filed: March 22, 1993
    Date of Patent: May 2, 1995
    Assignees: The Research Foundation of State University of New York, Solvay Interox
    Inventors: Raymond C. Francis, Xioa-Zhu Zhang, Nicholas A. Troughton
  • Method for reducing thermal and light-induced brightness reversion in lignin-containing pulps
    Patent number: 5360515
    Abstract: A method and article of manufacture thereof is provided for reducing brightness reversion in bleached lignin-containing pulps or newsprint by the treatment of the bleached lignin-containing pulp or newsprint with 2,5-dihydroxydioxane. In one embodiment, calcium carbonate is added to enhance the activity of 2,5-dihydroxydioxane.
    Type: Grant
    Filed: August 25, 1993
    Date of Patent: November 1, 1994
    Assignees: The Research Foundation of the State University of New York, Minerals Technology Inc.
    Inventors: Raymond C. Francis, Daniel B. Evans
  • Method for reducing brightness reversion in lignin-containing pulps and article of manufacture thereof
    Patent number: 5080754
    Abstract: A method and article of manufacture thereof is provided for reducing brightness reversion in bleached lignin-containing pulps or newsprint by the treatment of the bleached lignin-containing pulp or newsprint with a compound which donates a hydrogen atom to a photo-excited group or free radical more easily than does the lignin contained in the treated pulp. The hydrogen donating compounds include compounds with certain formyl functionality, including formate salts such as sodium, magnesium and calcium formate, formamides, formic acid esters, and formylurea. In one embodiment, calcium carbonate is added to enhance the activity of the formyl compound. The further addition of a trace amount of superoxide anion quencher such as copper sulfate or ascorbic acid is also provided to still further enhance the activity of the formyl compound, especially formate salts.
    Type: Grant
    Filed: July 20, 1990
    Date of Patent: January 14, 1992
    Assignee: The Research Foundation of State University of NY
    Inventors: Raymond C. Francis, Carlton W. Dence, Thomas C. Alexander
  • Process for the oxidative delignification of demethylated chemical pulp
    Patent number: 4729817
    Abstract: The extent of delignification of chemical pulps by oxygen-containing chemicals, preferably hydrogen peroxide, is enhanced by demethylating the pulp prior to such oxidative delignification, to a degree of demethylation of at least about 30%, preferably at least about 50%. Demethylation may be achieved by chemical treatment of the already-formed pulp or by modification to the pulping process to result in demethylated pulp.
    Type: Grant
    Filed: December 19, 1985
    Date of Patent: March 8, 1988
    Assignee: Tenneco Canada Inc. (ERCO division)
    Inventors: Raymond C. Francis, Douglas W. Reeve