Process of coating a substrate with an abrasion resistant ultraviolet curable composition

• US 4,478,876 A
• Filed: 01/17/1983
• Issued: 10/23/1984
• Est. Priority Date: 12/18/1980
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Chung, Rack H.
• Primary Examiner(s): Morris, Theodore
• Application Number:
  US06/458,820
• Time in Patent Office: 645 Days
• Field of Search: 204/159.13, 427/54.1
• US Class Current: 427/515
• CPC Class Codes: C08F 222/102 of dialcohols, e.g. ethylene glycol di(meth)acrylate or 1,4-butanediol dimethacrylate
• CPC Class Codes: C08F 230/00 Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and containing phosphorus, selenium, tellurium or a metal metal salts, e.g. phenolates or alcoholates, see the parent compounds
• CPC Class Codes: C08J 2369/00 Characterised by the use of polycarbonates; Derivatives of polycarbonates
• CPC Class Codes: C08J 2483/04 Polysiloxanes
• CPC Class Codes: C08J 7/0427 with only one layer of a composition containing a polymer binder with more layers C08J7/042
• CPC Class Codes: C08J 7/043 Improving the adhesiveness of the coatings per se, e.g. forming primers adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50
• CPC Class Codes: C08J 7/046 Forming abrasion-resistant coatings; Forming surface-hardening coatings
• CPC Class Codes: C09D 4/00 Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/31529 Next to metal
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

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, SiO₂ in the form of colloidal silica, and acryloxy functional silanes and a selected blend of ketone-type and hindered amine-type photoinitiators.

Claims

1. 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 R⁴ is a monovalent hydrocarbon radical, R⁵ is a divalent hydrocarbon radical, R⁶ 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.

2. A process as in claim 1 wherein said non-inert atmosphere is air.

3. A process as in claim 1 wherein said solid substrate is selected from the group consisting of polycarbonate, polyester, polymethyl methacrylate, polyacrylate, polyamide, nylon, metal or metalized plastic.

4. A process as in claim 1 wherein said coating is applied in a thickness of, approximately, 0.05 to 4.0 mils.

5. A process as in claim 1 wherein said ketone is selected from the group consisting of:

benzophenone, acetophenone,

benzil, benzaldehyde, o-chlorobenzaldehyde,

xanthone,

thioxanthone,

2-chlorothioxanthone,

9, 10-phenanthrenequinone,

9, 10-anthraquinone,

ethylbenzoin ether,

isopropyl benzoin ether,

a,a-dimethoxy-a-phenylacetophenone,

a, a-diethoxyacetophenone, and

1-phenyl-1, 2-propanediol-2-o-benzoyl oxime.

6. A process as in claim 1 wherein said hindered amine is selected from the group consisting of:

methyldiethanol amine,

ethyldiethanol amine,

dimethylethanol amine,

diethylethanol amine,

triethanol amine,

dimethylamino ethylbenzoate,

ethyl-3-dimethyl amino benzoate,

4-dimethyl amino benzophenone,

4-diethyl aminobenzophenone,

4, 4'"'"'-bis(diethylamino) benzophenone,

4, 4'"'"'-bis(dimethylamino) benzophenone,

N, N-diethyl aniline,

phenyl methyl ethanol amine,

phenyl ethyl ethanol amine,

phenyl diethanol amine, and

N,N,N¹,N¹ tetramethyl - 1,3 -butanediamine.

7. A process as in claim 1 wherein said photoinitiator blend is present in an amount of, approximately, 0.01 to 10 percent by weight of the ultraviolet light curable hardcoating composition.

8. A process as in claim 7 wherein said photoinitiator blend is comprised of benzophenone and methyldiethanol amine.

9. The process of claim 1 wherein said composition contains a mixture of hexanediol diacrylate and trimethylolpropane triacrylate monomers.

23. A process as in claim 1 or 20 wherein said composition contains a mixture of diethylenglycol diocrylate and trimethylolpropane triacrylate.

10. 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 R⁴ is a monovalent hydrocarbon radical, R⁵ is a divalent hydrocarbon radical, R⁶ 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.

11. A process as in claim 10 further comprising the step of coating said hardcoating composition onto a solid substrate.

12. A process as in claim 11 further comprising the step of curing said hardcoating composition by exposure to an effective amount of ultraviolet radiation.

13. A process as in claim 10 wherein said ketone is selected from the group consisting of:

benzophenone, acetophenone,

benzil, benzaldehyde, o-chlorobenzoldehyde,

xanthone,

thioxanthone,

2-chlorothioxanthone,

9, 10-phenanthrenequinone,

9, 10-anthraquinone,

ethylbenzoin ether,

isopropyl benzoin ether,

a,a,-dimethoxy-a-phenylacetophenone

a, a-diethoxyacetophenone, and

1-phenyl-1, 2-propanediol-2-o-benzoyl oxime.

14. A process as in claim 10 wherein said hindered amine is selected from the group consisting of:

methyldiethanol amine,

ethyldiethanol amine,

dimethylethanol amine,

diethylethanol amine,

triethanol amine,

dimethylamino ethylbenzoate,

ethyl-3-dimethyl amino benzoate,

4-dimethyl amino benzophenone,

4-diethyl aminobenzophenone,

4, 4'"'"'-bis(diethylamino) benzophenone,

4, 4'"'"'-bis(dimethylamino) benzophenone,

N, N-diethyl aniline,

phenyl methyl ethanol amine,

phenyl ethyl ethanol amine,

phenyl diethanol amine,

N,N,N¹,N¹ tetramethyl - 1,3 -butanediamine.

15. A process as in claim 10 further comprising the step of mixing an ultra-violet light screening agent into said hardcoating composition.

16. A process as in claim 15 wherein said screening agent is selected from esorcinol monobenzoate, resorcinol dibenzoate, methyl resorcinol monobenzoate, methyl resorcinol dibenzoate.

17. A process as in claim 10 further comprising a surface active agent.

18. A process as in claim 10 wherein said photoinitiator blend is present in an amount of, approximately, 0.01% to 10% by weight of the ultraviolet light curable hardcoating composition.

19. A process as in claim 18 wherein said photoinitiator blend is comprised of benzophenone and methyldiethanol amine.

20. A process as in claim 10 wherein said composition contains a mixture of hexanediol diacrylate and trimethylolpropane triacrylate monomers.

21. A process as in claim 10 wherein said process is carried out under a non-inert atmosphere.

22. A process as in claim 21 wherein said non-inert atmosphere is air.