Process for making an abrasion resistant coating onto an organic glass substrate

• US 6,514,574 B1
• Filed: 06/29/2000
• Issued: 02/04/2003
• Est. Priority Date: 06/29/2000
• Status: Expired due to Term

• Current Assignee: Essilor International SA
• Original Assignee: Essilor International Compagnie Generale D Optique (Essilor International SA)
• Inventors: Valeri, Robert Alan, White, Sidney Shaw Jr., Anderson, Kimberly Denise
• Primary Examiner(s): PIANALTO, BERNARD D
• Application Number:
  US09/607,542
• Time in Patent Office: 950 Days
• Field of Search: 427/515, 427/557, 427/558, 427/559, 427/164, 427/386, 427/387, 427/393.5
• US Class Current: 427/515
• CPC Class Codes: C08G 77/04 Polysiloxanes
• CPC Class Codes: C08G 77/08 characterised by the catalysts used
• CPC Class Codes: C08J 2383/04 Polysiloxanes
• CPC Class Codes: C08J 2483/00 Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen, or carbon only; Derivatives of such polymers
• CPC Class Codes: C08J 3/243 Two or more independent types of crosslinking for one or more polymers
• 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 428/31511 Of epoxy ether
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

The process comprises, (a) adding to a polymerizable composition containing a component A comprising at least one silane compound containing at least one epoxy group and at least two alkoxy groups directly bonded to the Si atom of the molecule or hydrolysate thereof and a component B comprising fine particles of silica, an effective amount of at least one cationic photopolymerization initiator and an effective amount of at least one thermal polymerization catalyst, (b) coating at least one surface of the substrate with the composition resulting from step (a), (c) submitting the coated substrate to a photopolymerization step for pre-curing the coating layer; and thereafter, (d) submitting the substrate with the pre-cured coating layer thereon to a thermal curing at a predetermined temperature and for a predetermined time to complete curing of the coating layer.

Claims

1. A process for making an abrasion-resistant coating onto at least one surface of a substrate made of an organic glass which comprises:

(a) preparing a polymerizable composition containing a component A comprising at least one silane compound containing at least one epoxy group and at least two alkoxy groups directly bonded to the Si atom of the molecule or a hydrolysate thereof and a component B comprising fine particles of silica, an effective amount of at least one cationic photopolymerization initiator and an effective amount of at least one thermal polymerization catalyst;

(b) coating at least one surface of the substrate with the composition resulting from step (a);

(c) submitting the coated substrate to a photopolymerization step for pre-curing the coating layer; and

thereafter;

(d) submitting the substrate with the pre-cured coating layer thereon to a thermal curing at a predetermined temperature and for a predetermined time to complete curing of the coating layer.

2. The process of claim 1, wherein photopolymerization step (c) comprises irradiating the coated substrate with a UV radiation for less than 1 minute.

3. The process of claim 1, wherein the thermal curing step (d) lasts for less than 1 minute.

4. The process of claim 1, wherein the thermal curing step (d) is effected at a temperature ranging from 50 to 500°

C.

5. The process of claim 1, wherein the cationic photoiniatiator is selected from the group consisting of aromatic onium salts and iron arene salt complexes.

6. The process of claim 1, wherein the cationic photoinitiator is present in an amount ranging from 0.1 to 3.0%.

7. The process of claim 1, wherein the thermal polymerization catalyst is present in an amount ranging from 0.005% to 0.25%.

8. The process of claim 1, wherein the thermal polymerization catalyst is selected from titanium complexes.

9. The process of claim 1, wherein the thermal polymerization catalyst is a compound of formula:

10. The process of claim 1, wherein the silane compound containing at least one epoxy group and at least two alkoxy groups directly bonded to the Si atom of the molecule has formula:

wherein R¹ is an alkyl or alkoxy alkyl group having 1 to 4 carbon atoms;

R² is an alkyl or aryl group having 1 to 6 carbons atoms;

R³ is hydrogen or methyl group;

m is 2 or 3;

a is an integer from 1 to 6; and

b is 0,1 or 2.

11. The process of claim 1, wherein the silane compound containing at least one epoxy group and at least two alkoxy groups directly bonded to the Si atom of the molecule is selected from the group consisting of γ

-glycidoxypropyltrimethoxysilane, γ

-glycidoxypropyltriethoxysilane, γ

-glycidoxypropylmethyldimethoxysilane, γ

-glycidoxypropylmethyldiethoxysilane, γ

-glycidoxyethoxypropylmethyldimethoxysilane and mixture thereof.

12. The process of claim 1, wherein coating of the surface of the substrate with the composition is effected by spin coating.

13. The process of claim 1, wherein the substrate is selected from (meth)acrylic resins, diethyleneglycol bisallyl carbonate copolymers, (halogenated) bisphenol-A di(meth)acrylate homopolymers and copolymers, and (halogenated) bisphenol-A urethane-modified.

14. The process of claim 1, wherein the substrate is an optical or ophthalmic lens.