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US 12,448,535 B2Granted
Compositions for wetness indication
AssigneeChromatic Technologies, Inc.
InventorsTimothy J. Owen, William R. Bowers
Life of this patent
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Abstract
A composition, and methods of making and using such a composition, whereby the composition can include a printable ink formulation having a colorant which undergoes a visible color change upon exposure to a wetness threshold. The colorant can be highly resistant to leaching. Additionally, the colorant can be resistant to premature activation via ambient moisture or humidity.
Claims23
A composition comprising:
- a colorant which undergoes a visible color change upon exposure to an aqueous medium having a pH above the pKa of said colorant;
- a leaching inhibitor having a cationic charge;
- and
- a pH below the pKa of said colorant;
- wherein a molar ratio of said leaching inhibitor:said colorant is not greater than about 30:1;
- wherein said composition is in a liquid state at room temperature;
- wherein upon application to a substrate, said composition comprises a non-activated state in which said colorant has a neutral charge and is in a first color state associated therewith;
- wherein upon exposure to said aqueous medium, said composition comprises an activated state in which said colorant is anionic and in a second color state associated therewith;
- and
- wherein upon exposure to said aqueous medium, said colorant having said anionic charge resists leaching from said substrate by being chemically bound to said leaching inhibitor having said cationic charge.
7 more elements
A method for visually determining whether a composition has been exposed to a wetness threshold, comprising:
- visually observing said composition comprising:
- a colorant which undergoes a visible color change upon exposure to an aqueous medium having a pH above the pKa of said colorant;
- a leaching inhibitor having a cationic charge;
- and
- a pH below the pKa of said colorant;
- wherein a molar ratio of said leaching inhibitor:said colorant is not greater than about 30:1;
- wherein said composition is in a liquid state at room temperature;
- wherein upon application to a substrate, said composition comprises a non-activated state in which said colorant has a neutral charge and is in a first color state associated therewith;
- wherein upon exposure to said aqueous medium, said composition comprises an activated state in which said colorant is anionic and in a second color state associated therewith;
- and
- wherein upon exposure to said aqueous medium, said colorant having said anionic charge resists leaching from said substrate by being chemically bound to said leaching inhibitor having said cationic charge;
- and
- wherein visual detection of said color change indicates that said composition was exposed to said wetness threshold.
10 more elements
A method of making a composition, comprising:
- combining:
- a colorant which undergoes a visible color change upon exposure to an aqueous medium having a pH above the pKa of said colorant;
- and
- a leaching inhibitor having a cationic charge;
- wherein a pH of said composition is below the pKa of said colorant;
- wherein a molar ratio of said leaching inhibitor:said colorant is not greater than about 30:1;
- wherein said composition is in a liquid state at room temperature;
- wherein upon application to a substrate, said composition comprises a non-activated state in which said colorant has a neutral charge and is in a first color state associated therewith;
- wherein upon exposure to said aqueous medium, said composition comprises an activated state in which said colorant is anionic and in a second color state associated therewith;
- and
- wherein upon exposure to said aqueous medium, said colorant having said anionic charge resists leaching from said substrate by being chemically bound to said leaching inhibitor having said cationic charge.
8 more elements
Dependencies are inferred from the claim text.