Coating composition
US4191804A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1978 |
| Grant date | Mar 4, 1980 |
| Priority date | — |
| Expiry date | Jun 30, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31862
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An improved pigment-free abrasion resistant coating composition for plastic substrates which is particularly suited for the protective coating of optical lenses formed from synthetic polymers such as acrylics, polyesters, polycarbonates, and the like. The coating composition is characterized by significantly improved adhesive qualities over prior art materials. The composition includes a major amount of a pigment-free aqueous composition comprising a dispersion of colloidal silica in a lower aliphatic alcohol-water solution of the partial condensate of a silanol of the formula RSi(OH).sub.3 in which R is selected from the group consisting of alkyl radicals of 1 to 3 inclusive carbons, the vinyl radical, cyanoethyl radical, the 3,3,3-trifluoropropyl radical, the gamma-glycidoxypropyl radical, at least 70 weight percent of the silanol being CH.sub.3 Si(OH).sub.3, said composition containing 10 to 50 weight percent solids consisting essentially of 10 to 70 weight percent colloidal silica and 30 to 90 weight percent of the partial condensate, said composition containing sufficient acid to provide a pH in the range of about 3 to about 6; and, based on the above solids from about 3.5% to…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.