CONTROL OF ATMOSPHERIC COMPOSITION DURING RADIATION CURING

• US 3,798,053 A
• Filed: 03/30/1971
• Issued: 03/19/1974
• Est. Priority Date: 03/30/1971
• Status: Expired due to Term

• Current Assignee: Thomas F. Huemmer
• Original Assignee: Thomas F. Huemmer
• Inventors: Huemmer, Thomas F.
• Primary Examiner(s): Martin, William D.
• Assistant Examiner(s): Newsome, John H.
• Application Number:
  US05/129,586
• Time in Patent Office: 1,085 Days
• Field of Search: 117/93.31,161KP,161ZB 118/49.1,49.5,620 250/49.5TE
• US Class Current: 427/495
• CPC Class Codes: B05D 3/0486 Operating the coating or treatment in a controlled atmosphere
• CPC Class Codes: B05D 3/068 using ionising radiations (gamma, X, electrons)

Abstract

A method for in situ radiation polymerization or curing of air inhibited compositions as coatings on substrates in the presence of limited but still substantial amounts of oxygen. As much as 7.5 percent by weight of oxygen may be present if the radiation dose is fixed by the formula:

Claims

2. In a method for applying a continuous coating to the exterior surface of an article of manufacture, wherein a flowable, polymerizable coating material comprising an epoxy acrylate containing halogen species is applied as a liquid film to said surface, and said film is polymerized in situ thereon by passing said film through a beam of polymerization effecting electrons from an electron beam, the improvement which comprises adjusting the oxygen content of the atmosphere at the point of incidence of said film and said beam of polymerization effecting electrons by the addition of an inert gas selected from the group consisting of carbon dioxide, nitrogen and mixtures thereof to said atmosphere, whereby said atmosphere contains from about 1.0 percent to about 7.5 percent by weight oxygen, subjecting said film to a minimum radiation dose equal to the oxygen content of the atmosphere (in percnet by weight) multiplied by 0.41, plus 1.3 MRads.

3. In a method of painting the exterior surface of a substrate, comprising applying a flowable, polymerizable coating material comprising a urethane acrylic oligomer to a substrate toform a film of up to about 10 mils average depth, passing said film through a beam of high energy ionizing radiation, the improvement which comprises adjusting the oxygen level of the atmosphere surrounding said film in the vicinity of said beam by passing nitrogen gas over said substrate, whereby the effective oxygen content of said atmosphere is from about 1.0% to about 7.5 percent by weight, subjecting said film to a radiation dose, the minimum of which equals one plus the oxygen content multiplied by 0.92 MRads.

4. In a method of painting the exterior surface of a substrate, comprising applying a flowable, polymerizable coating material comprising an epoxy acrylate containing halogen species to a substrate to form a film of up to about 10 mils average depth, passing said film through a beam of high energy ionizing radiation, the improvement which comprises adjusting the oxygen level of the atmosphere surrounding said film in the vicinity of said beam by passing nitrogen gas over said substrate, whereby the effective oxygen content of said atmosphere is from about 1.0 to about 7.5 percent by weight, subjecting said film to a radiation dose the minimum of which equals 1.3 plus the oxygen content multiplied by 0.41 MRads.