Patents by Inventor Steven D. Dawson

Steven D. Dawson 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: 6472469
    Abstract: Using urea extended phenolic binders with a resin to urea solids ratio below 60/40 can significantly reduce production costs in the manufacture of fiberglass products without adversely affecting product performance or producing formaldehyde or ammonia emissions at unacceptable levels. The phenolic binders are produced by reacting urea with phenolic resins that are prepared in a reaction in which the formaldehyde and phenol are initially present in mole ratios of greater than 3.75:1. In preparing the phenol/formaldehyde based binder, the molar ratio of free formaldehyde to urea must be carefully controlled in order to minimize emissions of ammonia and formaldehyde. Typically this molar ratio is kept between 0.8 and 1.0, therefore, higher free formaldehyde resins may be reacted with a higher percentage of urea to maintain the target formaldehyde to urea molar ratio. No ammonia is needed in the making the phenolic binder.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: October 29, 2002
    Assignee: Johns Manville International, Inc.
    Inventors: Derek C. Bristol, Thomas J. Taylor, Steven D. Dawson
  • Publication number: 20010036996
    Abstract: Using urea extended phenolic binders with a resin to urea solids ratio below 60/40 can significantly reduce production costs in the manufacture of fiber glass products without adversely affecting product performance or producing formaldehyde or ammonia emissions at unacceptable levels. The phenolic binders are produced by reacting urea with phenolic resins that are prepared in a reaction in which the formaldehyde and phenol are initially present in mole ratios of greater than 3.75:1. In preparing the phenol/formaldehyde based binder, the molar ratio of free formaldehyde to urea must be carefully controlled in order to minimize emissions of ammonia and formaldehyde. Typically this molar ratio is kept between 0.8 and 1.0, therefore, higher free formaldehyde resins may be reacted with a higher percentage of urea to maintain the target formaldehyde to urea molar ratio. No ammonia is needed in the making the phenolic binder.
    Type: Application
    Filed: March 16, 2001
    Publication date: November 1, 2001
    Inventors: Derek C. Bristol, Thomas J. Taylor, Steven D. Dawson