Patents Assigned to Chemfil Corporation
  • Patent number: 5238506
    Abstract: This invention relates to a method of coating metal surfaces including zinc-coated steel with zinc, nickel and manganese phosphate crystals for the purposes of improving paint adhesion, corrosion resistance, and resistance to alkali solubility. Potassium, sodium, or ammonium ions present as a phosphate salt are combined with zinc ions and nickel and manganese ions in relative proportions to cause the nickel and manganese ions to form a crystalline coating on the surface in combination with the zinc and phosphate.
    Type: Grant
    Filed: April 30, 1992
    Date of Patent: August 24, 1993
    Assignee: Chemfil Corporation
    Inventors: Thomas W. Cape, Harry R. Charles
  • Patent number: 5223141
    Abstract: A method for the removal and recovery of paint overspray in a water wash spray booth is disclosed. The method uses a circulating agitated dispersion of an organic solvent component in water which collects the paint overspray. The dispersion containing the overspray is permitted to phase separate into an organic phase and an aqueous phase. The organic phase is further treated such as by distillation to separate the paint solids from an organic solvent portion which contains the original organic solvent component and the organic solvents associated with the paint. The organic solvent portion can be recycled and reused in the circulating dispersion and the paint solids can be recovered for further use such as a filler for adhesives or can be disposed of.
    Type: Grant
    Filed: July 27, 1992
    Date of Patent: June 29, 1993
    Assignee: Chemfil Corporation
    Inventors: William B. Brown, Edmund L. Tisko, Harry R. Charles, Dean L. Miles
  • Patent number: 4941930
    Abstract: This invention relates to a method of coating metal surfaces including zinc-coated steel with zinc and nickel phosphate crystals for the purposes of improving paint adhesion, corrosion resistance, and resistance to alkali solubility. Potassium, sodium, or ammonium ions present as a phosphate salt are combined with zinc ions and nickel or manganese ions in relative proportions to cause the nickel or manganese ions to form a crystalline coating on the surface in combination with the zinc and phosphate.
    Type: Grant
    Filed: September 12, 1988
    Date of Patent: July 17, 1990
    Assignee: Chemfil Corporation
    Inventors: Harry R. Charles, Thomas W. Cape, Donald L. Miles
  • Patent number: 4828615
    Abstract: A solution containing pentavalent vanadium is applied to a metal surface subsequent to conversion coating. The solution contains pentavalent vanadium ions which may be obtained from a sodium metavanadate or sodium metavanadate/orthovanadate solution that is acidified with an acid. Vanadium pentoxide may be dissolved in a base such as sodium hydroxide, potassium hydroxide or lithium hydroxide to form a basic concentrate which can be acidified conveniently after dilution. In one disclosed embodiment, the solution comprises vanadium pentoxide, sodium hydroxide, nitric acid and water which is applied to a phosphate conversion coated surface than rinsed with deionized water prior to priming and painting.
    Type: Grant
    Filed: March 23, 1987
    Date of Patent: May 9, 1989
    Assignee: Chemfil Corporation
    Inventor: Thomas W. Cape
  • Patent number: 4793867
    Abstract: This invention relates to a method of coating metal surfaces including zinc-coated steel with zinc and nickel phosphate crystals for the purposes of improving paint adhesion, corrosion resistance, and resistance to alkali solubility. Potassium, sodium, or ammonium ions present as a phosphate salt are combined with zinc ions and nickel or manganese ions in relative proportions to cause the nickel or manganese ions to form a crystalline coating on the surface in combination with the zinc and phosphate.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: December 27, 1988
    Assignee: Chemfil Corporation
    Inventors: Harry R. Charles, Thomas W. Cape, Donald L. Miles
  • Patent number: 4748049
    Abstract: A crystal clear paint spray booth barrier coating comprising an aqueous solution of polyvinyl alcohol is disclosed. The polyvinyl alcohol may include a foam depressor for spray application of said coating. Fluorocarbon and non-ionic surfactants are disclosed for providing a smooth coating surface and improving the transparency of said coating. A polyacrylate thickener may be included to facilitate applying the coating to vertical surfaces. Methylparaben is disclosed for preventing the formation of mold on said coating and improving shelf life of the coating. The method disclosed includes mixing an aqueous solution of polyvinyl alcohol, at least one surfactant and a foam depressor, applying said mixture to the surfaces of the paint spray booth to be protected and equipment located in the paint spray booth, and allowing the coating to dry to a crystal clear coating. Methods of removing the coating include peeling the coating off as a film and water washing the coating.
    Type: Grant
    Filed: March 27, 1986
    Date of Patent: May 31, 1988
    Assignee: Chemfil Corporation
    Inventors: Harry R. Charles, Cathy D. Stewart
  • Patent number: 4699730
    Abstract: The paint denaturant composition of this invention includes mixing magnesium sulfate with complex silicate minerals. The complex silicate minerals disclosed include bentonite clay, kaolin clay, and diatomite preferably a mixture thereof. The paint denaturant composition as disclosed is preferably a slurry but may be a dry powder composition. Additives incorporating magnesium sulfate, or a combination of magnesium sulfate, a polyelectrolyte and water, are also disclosed for use with paint denaturant compositions including silicate minerals. The addition of a polyelectrolyte solution to the magnesium sulfate and complex silicate mineral paint denaturant composition is also disclosed for improving floculation prior to filtration or mechanical separation.
    Type: Grant
    Filed: May 24, 1985
    Date of Patent: October 13, 1987
    Assignee: Chemfil Corporation
    Inventors: Donald L. Miles, Harry R. Charles
  • Patent number: 4330345
    Abstract: This invention relates to a method of coating a metal surface with zinc and iron phosphate crystals for the purpose of improving corrosion resistance by means of a buffered zinc phosphate solution containing zinc dihydrogen phosphate and a monovalent, alkali metal salt of phosphate in proportions such that a fine, horizontal crystal structure consisting of tertiary zinc phosphate, zinc ferrous phosphate and other crystals of zinc ferrous phosphate is formed on the metal surface. The invention also relates to this composition.
    Type: Grant
    Filed: December 8, 1980
    Date of Patent: May 18, 1982
    Assignee: Chemfil Corporation
    Inventors: Donald L. Miles, Harry R. Charles