US 8,568,834 B2 · Superhydrophilic coating compositions and their preparation

Abstract

A method is provided for preparing on the surface of a substrate a superhydrophilic layer containing at least one metal oxide which method comprises calcining at elevated temperatures a cross-linked precursor film in which film the metal oxide is evenly distributed and immobilized. The precursor film is prepared by sequentially applying to the surface of the substrate a polyamine or other cationic polymer, a suspension of metal oxide and then a suitable cross linking agent. The superhydrophilic layer can be applied as a coating to a variety of substrates including metal, glass and ceramic and provides excellent dirt resistance, scratch resistance and antifogging effect. Multi-layer systems are also available using the inventive process.

Claims11

Dependent claims

A method for preparing a superhydrophilic layer comprising one or more metal oxides on a substrate which method comprises:

(a) first coating the substrate with a cationic polymer, followed by
(b) applying to the substrate coated by the cationic polymer a suspension, in a solvent, of amorphous particles of one or more metal oxides selected from the group consisting of oxides of silicon, zinc and titanium, wherein the particles have a particle diameter of from about 20 nm to about 80 nm, to form a single layer film;
(c) cross linking the thus obtained single layer film by applying a cross linking agent followed by drying to obtain a precursor film;
and then
(d) calcining the precursor film at temperatures ranging from about 400° C. to about 600° C. for about 1 to 8 hours.

2 more elements

Dependencies are inferred from the claim text.

Superhydrophilic coating compositions and their preparation

Life of this patent

Superhydrophilic coating compositions and their preparation

Life of this patent

Abstract

Claims11