Facemasks containing an anti-fog / anti-glare composition
View Patent ↗A coating composition that is incorporated into a facemask to reduce fogging and glare is provided. For example, in one embodiment, the facemask contains a shield or visor formed from a transparent substrate having at least one surface applied with the coating composition of the present invention. The present inventors have unexpectedly discovered that one or more water-soluble organic polymers, such as ethyl hydroxyethylcellulose, may be utilized as a principal component of the coating composition to reduce fogging and glare in a simple, yet effective manner.
1. A facemask comprising a substrate, wherein a coating is present on at least one surface of said substrate, the coating having a thickness of from about 50 to about 250 nanometers and consisting essentially of organic polymers, wherein the organic polymers include a cellulosic ether and constitute at least about 90 wt. % of said coating, and the substrate forms a visor or shield of the facemask.
2. A facemask as defined in claim 1 , wherein said substrate is transparent.
3. A facemask as defined in claim 1 , wherein said substrate is a polyester film.
4. A facemask as defined in claim 1 , wherein said coating comprises at least one organic polymer having an index of refraction of from 1.0 to 1.7.
5. A facemask as defined in claim 1 , wherein said coating comprises at least one organic polymer having an index of refraction of from 1.2 to 1.4.
6. A facemask as defined in claim 1 , wherein said coating comprises at least one organic polymer having an index of refraction of from 1.25 to 1.36.
7. A facemask as defined in claim 1 , wherein said cellulosic ether is nonionic.
8. A facemask as defined in claim 7 , wherein said nonionic cellulosic ether is selected from the group consisting of alkyl cellulose ethers, hydroxyalkyl cellulose ethers, alkyl hydroxyalkyl cellulose ethers, and combinations thereof.
9. A facemask as defined in claim 8 , wherein said nonionic cellulosic ether includes an alkyl hydroxyalkyl cellulose ether.
10. A facemask as defined in claim 9 , wherein said nonionic cellulosic ether includes ethyl hydroxyethyl cellulose.
11. A facemask as defined in claim 1 , wherein said cellulosic ether is cationic.
12. A facemask as defined in claim 11 , wherein said cellulosic ether is modified with a quaternary ammonium group.
13. A facemask as defined in claim 1 , wherein said coating comprises less than about 10 wt. % of surfactants.
14. A facemask as defined in claim 1 , wherein said coating comprises less than about 1 wt. % of surfactants.
15. A facemask as defined in claim 1 , wherein said coating further comprises antiblocking particles.
16. A facemask as defined in claim 1 , wherein said coated substrate exhibits a transmission of normal incident light of greater than about 3% when compared to an uncoated substrate.
17. A facemask as defined in claim 1 , wherein said coated substrate exhibits a transmission of normal incident light of greater than about 5% when compared to an uncoated substrate.
18. A facemask as defined in claim 1 , wherein said coated substrate exhibits a transmission of normal incident light of greater than about 8% when compared to an uncoated substrate.
19. A facemask as defined in claim 1 , wherein the haze of said substrate subtracted by the haze of an uncoated substrate is less than 0%.
20. A facemask as defined in claim 1 , further comprising a filter body attached to said visor or shield.
21. A facemask comprising a transparent visor or shield, wherein a coating is present on at least one surface of said transparent visor or shield that consists essentially of one or more cellulosic ethers, wherein the one or more cellulosic ethers constitute at least about 90 wt. % of said coating, wherein said coating has a thickness of from about 50 to about 250 nanometers.
22. A facemask as defined in claim 21 , wherein said one or more cellulosic ethers include an alkyl hydroxyalkyl cellulose ether.
23. A facemask as defined in claim 22 , wherein said one or more cellulosic ethers include ethyl hydroxyethyl cellulose.
24. A facemask as defined in claim 21 , wherein said coating comprises less than about 10 wt. % of surfactants.
25. A facemask as defined in claim 21 , wherein said coating comprises less than about 1 wt. % of surfactants.
26. A method for forming a facemask that comprises a transparent substrate, said method comprising:
applying an aqueous composition to at least one surface of the transparent substrate, said aqueous composition including a mixture of water and one or more water-soluble organic polymers selected from the group consisting of cellulosic ethers;
drying said aqueous composition to form a coating on said transparent substrate, wherein said coating has a thickness of from about 50 to about 260 nanometers and consists essentially of one or more cellulosic ethers, wherein the one or more cellulosic ethers constitute at least about 90 wt. % of said coating, and the substrate forms a visor or shield of the facemask.
27. A method as defined in claim 26 , wherein said one or more water-soluble organic polymers include a nonionic cellulosic ether.
28. A method as defined in claim 27 , wherein said cellulosic ether includes an alkyl hydroxyalkyl cellulose ether.
29. A method as defined in claim 28 , wherein said cellulosic ether includes ethyl hydroxyethyl cellulose.
30. A method as defined in claim 26 , wherein water constitutes at least about 75 wt. % of said aqueous coating composition.
31. A method as defined in claim 26 , wherein said one or more water-soluble organic polymers constitute from about 0.01 wt. % to about 5 wt. % of said aqueous coating composition.
32. A method as defined in claim 26 , wherein said one or more water-soluble organic polymers constitute from about 0.2 wt. % to about 0.75 wt. % of said aqueous coating composition.
33. A method as defined in claim 26 , further comprising attaching said visor or shield to a filter body.
34. A method as defined in claim 26 , wherein said coating comprises less than about 10 wt. % of surfactants.
35. A method as defined in claim 26 , wherein said coating comprises less than about 1 wt. % of surfactants.