×

Color changing compositions

  • US 5,326,388 A
  • Filed: 07/16/1993
  • Issued: 07/05/1994
  • Est. Priority Date: 07/31/1992
  • Status: Expired due to Term
First Claim
Patent Images

1. A multiple coloring composition system comprising:

  • (a) an undercolor aqueous coloring composition comprising an undercolor dye whose coloring ability is destroyed in the presence of a pH of about 10 or greater; and

    (b) an overcolor aqueous coloring composition comprising a colorant capable of maintaining its characteristic color in the presence of a pH of about 10 or greater and an effective amount of a base sufficient to yield a pH of said overcolor aqueous coloring composition of about 10 or greater.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×