Patents by Inventor Narayan Das

Narayan Das 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: 6027579
    Abstract: The invention provides a non-chrome rinse and method for treating a phosphate conversion-coated ferrous metal substrate. The rinse comprising zirconium ions, vanadium ions, fluoride ions, and phosphate ions in a ratio and a concentration effective for providing the phosphate conversion-coated ferrous metal substrate with improved corrosion resistance.
    Type: Grant
    Filed: July 7, 1997
    Date of Patent: February 22, 2000
    Assignee: Coral Chemical Company
    Inventors: Narayan Das, John P. Jandrists
  • Patent number: 5332452
    Abstract: An aqueous, acidic composition for application to aluminum and aluminum alloy surfaces comprising a source of zirconium ions, a source of fluoride ions, a source of phosphate ions, a phosphate acid ester, a polyethylene glycol ester of a fatty acid, and nitric acid, and a method for treating aluminum and aluminum alloy surfaces with such a composition.
    Type: Grant
    Filed: May 28, 1992
    Date of Patent: July 26, 1994
    Assignee: Coral International, Inc.
    Inventor: Narayan Das
  • Patent number: 5279677
    Abstract: An aqueous composition for treating metal surfaces, particularly formed aluminum and aluminum alloy surfaces, comprising a surface tension reducing agent selected from the group consisting of sulfosuccinate salts and derivatives and mixtures thereof, a surfactant selected from the group consisting of propoxylated and ethoxylated linear alcohols, and an acid such as phosphoric acid, as well as preferably a bactericide and a defoamant, and a method for treating metal surfaces, particularly beverage containers, such as of aluminum and aluminum alloy with such a composition.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: January 18, 1994
    Assignee: Coral International, Inc.
    Inventor: Narayan Das
  • Patent number: 5139586
    Abstract: An aqueous, acidic composition for application to aluminum and aluminum alloy surfaces comprising a source of zirconium ions, a source of fluoride ions, a source of phosphate ions, a phosphate acid ester, a polyethylene glycol ester of a fatty acid, and nitric acid, and a method for treating aluminum and aluminum alloy surfaces with such a composition.
    Type: Grant
    Filed: February 11, 1991
    Date of Patent: August 18, 1992
    Assignee: Coral International, Inc.
    Inventor: Narayan Das
  • Patent number: 4470853
    Abstract: An aqeuous acidic composition provides improved coating for aluminum. The composition comprises from about 10 to about 150 ppm zirconium, from about 20 to about 250 ppm fluoride, from about 30 to about 125 ppm tannin, from about 15 to about 100 ppm phosphate and from about 5 to about 50 ppm zinc, said coating solution having a tannin to phosphate ratio in the range of at least about 1:1 to about 2:1 and a pH in the range of about 2.3 to about 2.95.
    Type: Grant
    Filed: October 3, 1983
    Date of Patent: September 11, 1984
    Assignee: Coral Chemical Company
    Inventors: Narayan Das, Peter M. Stastny
  • Patent number: 4422886
    Abstract: A low pH solution and a method for conversion coating aluminum and aluminum alloy surfaces, as well as the coated surfaces themselves, utilizing zirconium, fluoride and nickel and, optionally, fluorophosphate.
    Type: Grant
    Filed: March 16, 1983
    Date of Patent: December 27, 1983
    Assignee: Chemical Systems, Inc.
    Inventors: Narayan Das, Joy M. Schaefer
  • Patent number: 4391652
    Abstract: A low pH solution and a method for conversion coating aluminum and aluminum alloy surfaces, as well as the coated surfaces themselves, utilizing zirconium, fluoride and nickel and, optionally, fluorophosphate.
    Type: Grant
    Filed: January 29, 1982
    Date of Patent: July 5, 1983
    Assignee: Chemical Systems, Inc.
    Inventors: Narayan Das, Joy M. Schaefer
  • Patent number: 4381064
    Abstract: A stock material for producing seamless containers from a black plate base includes applying a layer of insoluble crystalline phosphate to each surface of the black plate and subsequently producing a thin film of organic lubricating material on the exposed surfaces of the phosphate layers so that a drawn and ironed container can be produced from a flat blank without the use of any additional lubricants during fabrication. The weight of the phosphate layer for each surface of the black plate base is preferably less than 100 milligrams per square foot, while the weight of lubricating film is on the order of 70 to 360 milligrams per square foot. In the preferred embodiment, the phosphate layer is preferably in the range of 20 to 35 milligrams per square foot, and the lubricant layer is on the order of 70 to 180 milligrams per square foot.
    Type: Grant
    Filed: March 2, 1981
    Date of Patent: April 26, 1983
    Assignee: National Can Corporation
    Inventors: Narayan Das, Surya K. Misra
  • Patent number: 4285223
    Abstract: A stock material for producing seamless containers from a black plate base includes applying a layer of insoluble crystalline phosphate to each surface of the black plate and subsequently producing a thin film of organic lubricating material on the exposed surfaces of the phosphate layers so that a drawn and ironed container can be produced from a flat blank without the use of any additional lubricants during fabrication. The weight of the phosphate layer for each surface of the black plate base is preferably less than 100 milligrams per square foot, while the weight of lubricating film is on the order of 70 to 360 milligrams per square foot. In the preferred embodiment, the phosphate layer is preferably in the range of 20 to 35 milligrams per square foot, and the lubricant layer is on the order of 70 to 180 milligrams per square foot.
    Type: Grant
    Filed: February 12, 1979
    Date of Patent: August 25, 1981
    Inventors: Narayan Das, Surya K. Misra
  • Patent number: 3964936
    Abstract: An acidic aqueous coating solution for forming on an aluminum surface a coating which is corrosion resistant and to which overlying coatings adhere excellently is disclosed. The coating solution contains compounds of zirconium and fluorine. The use of boric acid in the solution is disclosed also. The coating solution is capable of forming on an aluminum surface a uniformly colorless and clear coating so that the coated surface has the appearance of the underlying metal surface, that is, the coating can be formed without changing the appearance of the metal surface. When coating a shiny bright aluminum surface, there can be produced a coated surface having a uniformly shiny bright appearance which is maintained even after the coated surface is subjected to boiling water.
    Type: Grant
    Filed: December 17, 1974
    Date of Patent: June 22, 1976
    Assignee: Amchem Products, Inc.
    Inventor: Narayan Das