Reversible color-changing sanitizer-indicating nonwoven wipe

Patent metadata

Field	Value
Publication number	US-9861245-B2
Application number	US-201414284866-A
Country	US
Kind code	B2
Filing date	May 22, 2014
Priority date	Mar 31, 2009
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

A nonwoven wipe having a reversible sanitizer indicator for multiple uses and recharges is provided. The nonwoven wipe includes a cloth-like nonwoven fabric coated with a reversible color-changing ink formulation. During use, the nonwoven wipe is impregnated with a quaternary ammonium compound-based sanitizer. When the level of free quaternary ammonium compound falls below a threshold level, the color-changing ink formulation changes from a first color to a second color, indicating the need to recharge the wipe. When the nonwoven wipe is recharged with sanitizer solution, the color-changing ink formulation changes back to the first color.

First claim

We claim:

1. A method of making an article having reversible color-changing properties, comprising the steps of:
providing a fabric formed of flexible polymeric material;
applying a solution including a reversible color-changing ink formulation and a solvent to the fabric;
drying the solution on the fabric to remove the solvent; and
permanently binding the reversible color-changing ink formulation to the fabric;
wherein the reversible color-changing ink formulation comprises a polymer binder, a plasticizer, a wetting agent and an anionic indicator compound, and the drying causes the reversible color-changing ink formulation to permanently bind to the fabric; and
impregnating the dried fabric with a quaternary ammonium compound-based sanitizer solution;
wherein the article changes back and forth between a first color and a second color during at least four cycles of impregnation with the quaternary ammonium compound-based sanitizer solution followed by depletion of the quaternary ammonium compound-based sanitizer solution from the article.

2. The method of claim 1 , further comprising heating the fabric to perform the drying.

3. The method of claim 2 , wherein the fabric is heated to a temperature of about 40° C. to about 60° C.

4. The method of claim 1 , further comprising applying a vacuum to the fabric.

5. The method of claim 1 , wherein the reversible color-changing ink formulation comprises about 10-50% by weight of the polymer binder, about 10-50% by weight of the plasticizer, about 10-50% by weight of the wetting agent, and about 1-10% by weight of the anionic indicator compound, based on a dry weight of the reversible color-changing ink formulation.

6. The method of claim 1 , wherein the solution comprises about 15-50% by weight of the reversible color-changing ink formulation.

7. The method of claim 1 , wherein the solvent is selected from the group consisting of n-propyl acetate, acetone, methylethyl ketone, toluene, tetrahydrofuran, ethyl acetate, and combinations thereof.

8. The method of claim 1 , wherein the polymer binder comprises a polymer selected from the group consisting of cellulose acetate, cellulose acetate derivatives, carboxymethyl cellulose, ethyl cellulose, nitrocellulose, and combinations thereof.

9. The method of claim 1 , wherein the plasticizer comprises a compound selected from the group consisting of dibutyl phthalate, triethyl citrate, bis-(2-butoxylethyl) adipate, bis-(2-ethylhexyl) sebacate, diethyl phthalate, and combinations thereof.

10. The method of claim 1 , wherein the wetting agent comprises a compound selected from the group consisting of ethylene glycol, 2-ethoxy ethanol, triethylene glycol, sorbitol, and combinations thereof.

11. The method of claim 1 , wherein the anionic indicator comprises a compound selected from the group consisting of bromothymol blue, thymol blue, m-cresol purple, xylenol blue, xylenol orange, phenol red, and combinations thereof.

12. The method of claim 1 , wherein the flexible polymeric material is selected from the group consisting; of polyester, polypropylene, high density polyethylene, linear low density polyethylene, polyamides, polytetrafluoroethylene, and combinations thereof.

13. A method of imparting reversible color-changing properties to a polymeric article, comprising the steps of:
providing a polymeric article;
applying a solution including a reversible color-changing ink formulation to the polymeric article;
drying the solution on the polymeric article; and
permanently binding the reversible color-changing ink formulation to the polymeric article;
wherein the reversible color-changing ink formulation comprises a polymer binder, a plasticizer, a wetting agent and an anionic indicator compound, and the drying causes the reversible color-changing ink formulation to permanently bind to the polymeric article; and
impregnating the dried polymeric article with a quaternary ammonium compound-based sanitizer solution;
wherein the article changes back and forth between a first color and a second color during at least four cycles of impregnation with the quaternary ammonium compound-based sanitizer solution followed by depletion of the quaternary ammonium compound-based sanitizer solution from the article.

14. The method of claim 13 , wherein the anionic indicator compound causes the reversible color-changing ink formulation to change back and forth between the first color when the quaternary ammonium compound exceeds a threshold concentration and the second color when the quaternary ammonium compound falls below the threshold concentration.

15. The method of claim 14 , wherein the threshold concentration is about 190-220 ppm.

16. The method of claim 13 , wherein the polymer binder comprises a polymer selected from the group consisting of cellulose acetate, cellulose acetate derivatives, carboxymethyl cellulose, ethyl cellulose, nitrocellulose, and combinations thereof.

17. The method of claim 13 , wherein the plasticizer comprises a compound selected from the group consisting of dibutyl phthalate, triethyl citrate, bis-(2-butoxylethyl) adipate, bis-(2-ethylhexyl) sebacate, diethyl phthalate, and combinations thereof.

18. The method of claim 13 , wherein the wetting agent comprises a compound selected from the group consisting of ethylene glycol, 2-ethoxy ethanol, triethylene glycol, sorbitol, and combinations thereof.

19. The method of claim 13 , wherein the anionic indicator comprises a compound selected from the group consisting of bromothymol blue, thymol blue, m-cresol purple, xylenol blue, xylenol orange, phenol red, and combinations thereof.

20. A method of monitoring a concentration of quaternary ammonium-containing compound using a polymeric article, comprising the steps of:
contacting a quaternary ammonium compound-containing solution to the polymeric article;
using the polymeric article, causing a reduction in the quaternary ammonium compound below a threshold concentration wherein the polymeric article changes from a first color to a second color; and
contacting more of the quaternary ammonium compound-containing solution to the used polymeric article until the quaternary ammonium compound exceeds the threshold concentration wherein the polymeric article changes from the second color back to the first color;
wherein the polymeric article comprises a reversible color-changing ink formulation permanently bound thereto using a polymer binder;
wherein the article changes back and forth between the first color and the second color during at least four cycles of contacting with the quaternary ammonium-compound containing solution followed by depletion of the quaternary ammonium compound-containing solution from the article.

Assignees

• Farrugia Darren J
• Ward Lesley J
• Reichert Veronica R
• Illinois Tool Works

Inventors

• Farrugia Darren J
• Ward Lesley J
• Reichert Veronica R

Classifications

• D06P5/138

  fugitive dyeing · CPC title

• C11D1/62

  Quaternary ammonium compounds · CPC title

• Y10T442/2525

  Coating or impregnation functions biologically [e.g., insect repellent, antiseptic, insecticide, bactericide, etc.] · CPC title

• A47L13/17 Primary

  containing cleaning agents (A47L13/19 takes precedence {; chemical compositions C11D17/049}) · CPC title

• C11D3/48

  Medical, disinfecting agents, disinfecting, antibacterial, germicidal or antimicrobial compositions · CPC title