Silica Coating For Enhanced Hydrophilicity/Transmittivity
Assignee3M Innovative Properties Company
InventorsNaiyong Jing, Roxanne A. Boehmer, Xue-hua Chen, Zhigang Yu, Ying Zhang, Dang Xie, Bangwei Xi
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Abstract
A coated article having a substrate coated with a layer of silica nanoparticles is provided. The coating is substantially uniform in thickness, durably adheres to the substrate, and provides antireflection and or hydrophilic surface properties to the substrate.
Claims22
A method of providing a coating to a substrate comprising contacting a substrate with a coating composition comprising:
- a) 0.5 to 99 wt. % water
- b) 0.1 to 20 wt. % silica nanoparticles having an average particle diameter of 40 nm or less,
- c) 0 to 20 wt. % silica nanoparticles having an average particle diameter of 50 nm or more, wherein the sum of b) and c) is 0.1 to 20 wt. %;
- d) a sufficient amount of an acid having a pKa of <3.5 to reduce the pH to less than 5;
- e) 0 to 20 percent by weight of a tetraalkoxysilane, relative to the amount of the silica nanoparticle;
- and drying to provide a silica nanoparticle coating.
(canceled)
A coated article comprising a substrate and a coating thereon of agglomerates of silica nanoparticles having average particle diameters of 40 nanometers or less thereon, said agglomerates comprising a three-dimensional porous network of silica nanoparticles, and the silica nanoparticles are bonded to adjacent silica nanoparticles.
A coating composition comprising:
- f) 0.5 to 99 wt. % water,
- g) 0.1 to 20 wt. % silica nanoparticles having an average particle diameter of 40 nm or less,
- h) 0 to 20 wt. % silica nanoparticles having an average particle diameter of greater than 50 nm, wherein the sum of b) and c) is 0.1 to 20 wt. %;
- i) a sufficient amount of an acid having a pKa of <3.5 to reduce the pH to less than 5;
- 0 to 20 percent by weight of a tetraalkoxysilane, relative to the amount of the silica nanoparticles.
Dependencies are inferred from the claim text.