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Metal treatment

  • US 5,226,976 A
  • Filed: 04/15/1991
  • Issued: 07/13/1993
  • Est. Priority Date: 04/15/1991
  • Status: Expired due to Fees
First Claim
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1. A process for increasing the corrosion resistance of a metal object bearing a pre-existing protective conversion coating, said process comprising steps of:

  • (A) contacting the pre-existing coating with a composition having a pH from about 5 to about 12 and consisting essentially of;

    (1) water,(2) from 25-5000 ppm of triazole molecules selected from the group consisting of aryl triazoles containing from 6 to about 10 carbon atoms and alkyl triazoles containing from 1 to about 6 carbon atoms, and, optionally,(3) at least partially substituted poly(vinylphenol) polymer or copolymer including substituents on at least some of the phenol rings that have a chemical structure according to one of the formulas;

    ##STR6## wherein each of R5 through R12 is selected from hydrogen, an alkyl, an aryl, an aryl, a hydroxy-alkyl, an amino-alkyl, a mercapto-alkyl, or a phospho-alkyl moiety, except that R12 can also be --O.sup.(-1) or --OH and that at least one of R9 and R10 must include a polyhydroxy functionality resulting from the condensation of an amine or ammonia with a ketose, aldose, or other polyhydroxyl compound having from about 3 to about 8 carbon atoms, followed by reduction from imino to amino, and, optionally,(4) polar organic solvents; and

    (B) drying the object completion of step (A).

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