Process of coating a substrate with an abrasion resistant ultraviolet curable composition
AssigneeGeneral Electric Company
InventorRack H. Chung
Life of this patent
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Abstract
A process of coating a solid substrate with an abrasion resistant silicone hard coating composition which is curable upon exposure to ultraviolet radiation under a non-inert atmosphere, such as air, is provided. The coating composition is comprised of a combination of UV light crosslinkable polyfunctional acrylate monomers, SiO.sub.2 in the form of colloidal silica, and acryloxy functional silanes and a selected blend of ketone-type and hindered amine-type photoinitiators.
Claims23
A process for providing a mar resistant tenaciously and durably adhered hard coating onto the surface of a solid substrate comprising:
- I. applying a thin layer of a coating composition onto the surface of said solid substrate, said coating composition being comprised of (A) at least one polyfunctional acrylate monomer represented by the general formula ##STR40## wherein n is an integer having a value of from 1 to 4, and R is selected from the group consisting of a n valent aliphatic hydrocarbon residue, a n valent substituted aliphatic hydrocarbon residue containing at least one ther linkage, and a n valent substituted aliphatic hydrocarbon residue containing at least one ether linkage, R' is selected from hydrogen or lower alkyl radicals;
- (B) colloidal silica;
- (C) at least one acryloxy functional silane of the formula ##STR41## wherein R.sup.4 is a monovalent hydrocarbon radical, R.sup.5 is a divalent hydrocarbon radical, R.sup.6 is selected from the group consisting of hydrogen atoms and monovalent hydrocarbon radicals, x is an integer of from 1 to 4 inclusive;
- (D) a photoinitiator comprised of a blend of (i) one or more ketones and (ii) one or more hindered amines;
- and
- II. exposing said coated substrate under a non-inert atmosphere to ultraviolet light for a period of time sufficient to polymerize and crosslink said polyfunctional acrylate monomers, thereby forming said hard coating.
A process for providing an abrasion resistant, durably adhered, ultraviolet light curable hardcoating composition which is curable in a non-inert atmosphere comprising the steps of mixing:
- (A) at least one ultraviolet light crosslinkable polyfunctional acrylate monomer represented by the general formula ##STR42## wherein n is an integer having a value of from 1 to 4, and R is selected from the group consisting of substituted and unsubstituted n valent aliphatic hydrocarbon residue, n valent aliphatic hydrocarbon residue containing at least one ether linkage, and substituted n valent aliphatic hydrocarbon residue containing at least one ether linkage, R' is selected from hydrogen or lower alkyl radicals;
- (B) colloidal silica;
- (C) at least one acryloxy functional silane of the formula ##STR43## wherein R.sup.4 is a monovalent hydrocarbon radical, R.sup.5 is a divalent hydrocarbon radical, R.sup.6 is selected from the group consisting of hydrogen atoms and monovalent hydrocarbon radicals, x is an integer of from 1 to 4 inclusive;
- (D) a photoinitiator comprised of a blend of (i) one or more ketones and (ii) one or more hindered amines, wherein said photoinitiator blend is effective for cross-linking (A) upon exposure to ultraviolet radiation.
Dependencies are inferred from the claim text.