Coating compositions, hydrophilic films, and hydrophilic film-coated articles
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsMasahiro Furuya, Masaaki Yamaya
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Abstract
A coating composition which is comprised of an emulsion of a silicone resin, typically a water-insoluble, silanol group-bearing silicone resin dispersed in water, and contains photocatalyst particles, typically titanium oxide forms a hydrophilic film having a water-drop contact angle of no more than 60.degree. when irradiated with UV-containing light. The composition eliminates the use of organic solvents and has excellent dispersion and storage stability. Films obtained by applying this coating composition to the surface of substrates have excellent weathering resistance and antifouling properties due to a self-cleaning effect arising from the photocatalytic action of the particles.
Claims14
A coating composition comprising an emulsion of a silicone resin dispersed in water, and photocatalyst particles, which forms a hydrophilic film having a water-drop contact angle of no more than 60.degree. when irradiated with UV-containing light, wherein said emulsion of a silicone resin dispersed in water is of an emulsion polymer which has been obtained from as main components:
- (i) 100 parts by weight of a water-insoluble, silanol group-bearing silicone resin of the average compositional formula (1):
- R.sup.1.sub.m R.sup.2.sub.n Si(OR.sup.3).sub.p (OH).sub.q O.sub.(4-m-n-p-q)/4 ( 1)
- wherein R.sup.1 is an unsubstituted monovalent hydrocarbon group;
- R.sup.2 is a substituted monovalent hydrocarbon group;
- R.sup.3 is an unsubstituted or substituted monovalent hydrocarbon group;
- and the letters m, n, p and q are numbers falling in the ranges 0.3.ltoreq.m.ltoreq.1.8, 0.ltoreq.n.ltoreq.1.0, 0.ltoreq.p.ltoreq.2.0, 0<q.ltoreq.1.7, 0.3.ltoreq.m+n.ltoreq.1.8, 0<p+q.ltoreq.3.0 and 0.3<m+n+p+q<4.0, and
- (ii) 10 to 1,000 parts by weight of a radical-polymerizable vinyl monomer,
- said emulsion being essentially free of organic solvents having a boiling point of less than 100.degree. C. and aromatic organic solvents.
Dependencies are inferred from the claim text.