Removable antifogging coatings, articles, coating compositions, and methods

Patent metadata

Field	Value
Publication number	US-10316212-B2
Application number	US-201615133262-A
Country	US
Kind code	B2
Filing date	Apr 20, 2016
Priority date	Dec 26, 2007
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A coating composition which imparts antifog properties to substrates coated therewith. The coating compositions are removable and utilize nanoparticles functionalized with epoxy groups. The removable coating compositions are particularly useful on personal protection equipment such as face masks, shields, and protective glasses.

First claim

What is claimed is:

1. A method of providing antifogging characteristics to a substrate, the method comprising:
a) obtaining an antifogging coating composition, the coating composition comprising
nanoparticles comprising a silica surface having functional groups attached to the surface through covalent bonds, wherein the functional groups comprise:
epoxy groups; and
optional water-dispersible groups;

optional surfactants;
optional antimicrobial agents;
optional organic solvents, wherein the optional organic solvents are present in an amount of no more than 30 wt-% of the total weight of the coating composition; and
water as a liquid carrier of the coating composition; and

b) applying the coating composition to a substrate and allowing it to dry, wherein the coating composition provides antifogging characteristics to the substrate on which it is coated and dried, and is removable after drying.

2. The method of claim 1 , wherein the obtaining the coating composition comprises preparing the coating composition by reacting one or more epoxy functional compounds with nanoparticles having an average particle size of no greater than 60 nm, wherein the reacting occurs in a mixture comprising water as a liquid carrier and having a pH of no greater than 6 for at least three hours.

3. The method of claim 2 , further comprising adjusting the pH of the mixture to be no greater than 6 prior to reacting the one or more epoxy functional compounds with the nanoparticles.

4. The method of claim 2 , wherein the reacting occurs in a mixture comprising water as a liquid carrier and having a pH of no greater than 6 for at least twelve hours.

5. The method of claim 4 , further comprising removing organic volatiles following reacting the one or more epoxy functional compounds with the nanoparticles.

6. The method of claim 2 , further comprising covalently attaching water-dispersible groups to the nanoparticles.

7. The method of claim 2 , wherein the mixture has a pH of 1 to 3 for at least three hours.

8. The method of claim 1 , wherein the nanoparticles are present in the antifogging coating composition in a concentration of no greater than 10 weight percent, based on the total weight of the coating composition.

9. The method of claim 2 , further comprising adding a surfactant following reacting the one or more epoxy functional compounds with the nanoparticles.

10. The method of claim 1 , wherein the coating composition comprises no more than 30 weight percent organic solvent, based on the total weight of the coating composition.

11. The method of claim 2 , further comprising adding an antimicrobial agent following reacting the one or more epoxy functional compounds with the nanoparticles.

12. The method of claim 1 , further comprising impregnating the coating composition into an applicator substrate prior to applying the coating composition to the substrate.

13. The method of claim 2 , further comprising adjusting the pH of the mixture to be between 6 and 8 following reacting the one or more epoxy functional compounds with the nanoparticles.

14. The method of claim 1 , further comprising wiping off the dried coating with a paper towel.

15. The method of claim 14 , wherein after wiping off the dried coating no residue of the dried coating remains on the substrate.

16. The method of claim 14 , further comprising applying the coating composition to the substrate and allowing it to dry, thereby providing a fresh layer of coating.

17. The method of claim 1 , wherein the coating composition is applied to the substrate using a paper wipe impregnated with the coating composition.

18. The method of claim 1 , wherein the coating composition is allowed to dry under ambient conditions.

19. The method of claim 1 , further comprising removing the dried coating; applying the coating composition to the substrate; and allowing it to dry, thereby providing a fresh layer of coating.

20. A method of making an antifogging coating composition, the method comprising reacting one or more epoxy functional compounds with nanoparticles having an average particle size of no greater than 60 nm, wherein the reacting occurs in a mixture comprising water as a liquid carrier and having a pH of no greater than 6 for at least three hours; and storing at least a portion of the coating composition in a sealed container for at least eight days and up to two years.

21. The method of claim 20 , further comprising impregnating the coating composition into an applicator substrate prior to storing the coating composition in the sealed container.

Assignees

• 3M Innovative Properties Co

Inventors

• Jing Naiyong
• Chen Xue-Hua
• Sun Ruo-Ni
• Yu Zhigang
• Xie Xiaoling
• Chen Jinyu

Classifications

• C09C1/00

  Treatment of specific inorganic materials other than fibrous fillers (tenebrescent materials C09K9/00; luminescent materials C09K11/00); Preparation of carbon black · CPC title

• C09C1/407

  Aluminium oxides or hydroxides · CPC title

• C09C3/12

  Treatment with organosilicon compounds {(C09C3/006 takes precedence)} · CPC title

• C09D1/00

  Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances · CPC title

• C03C17/32

  with synthetic or natural resins (C03C17/30 takes precedence) · CPC title