Heat curable epoxy compositions and transparent heat-cured coatings with durable adhesion prepared therefrom

Patent metadata

Field	Value
Publication number	US-11709290-B2
Application number	US-201917281053-A
Country	US
Kind code	B2
Filing date	Oct 3, 2019
Priority date	Oct 5, 2018
Publication date	Jul 25, 2023
Grant date	Jul 25, 2023

Abstract

The present disclosure provides heat-curable coating compositions for optical articles. The coating compositions include a multifunctional epoxy monomer in combination with a UV absorber. The inclusion of at least one multifunctional epoxy monomer and at least one UV absorber provide epoxy coatings that exhibit excellent adhesion on a variety of lens substrates.

First claim

The invention claimed is:

1. A heat-curable coating composition, comprising:
a) 20-40% by weight as compared to the total weight of the composition of at least one epoxy monomer comprising two or three epoxy groups, wherein the at least one epoxy monomer does not include hydrolyzable groups directly linked to a silicon atom;
b) 10-25% by weight as compared to the total weight of the composition of at least one hydroxylated epoxy monomer comprising at least three epoxy groups and one to three hydroxyl groups, wherein the hydroxylated epoxy monomer does not include hydrolyzable groups directly linked to a silicon atom;
c) at least one UV absorber comprising a hydroxyphenyl benzotriazole or hydroxyphenyl triazine; and
d) at least one epoxy ring-opening catalyst, wherein said epoxy ring-opening catalyst is an aluminum chelate, aluminum acrylate, aluminum alcoholate, triflic acid, or metal salt of triflic acid.

2. The composition of claim 1 , wherein the epoxy monomer is a diglycidyl ether, a triglycidyl ether, or a cycloaliphatic epoxy.

3. The composition of claim 1 , wherein the hydroxylated epoxy monomer is the sorbitol polyglycidyl ether of formula:

4. The composition of claim 1 , wherein the epoxy monomers and hydroxylated epoxy monomers comprise at least 50% by weight of all epoxy-containing compounds present in the composition.

5. The composition of claim 1 , wherein the composition further comprises at least one epoxysilane comprising at least one hydrolyzable group directly linked to the silicon atom and at least one epoxy group, or a hydrolyzate thereof.

6. The composition of claim 5 , wherein the epoxysilane is (3-glycidyloxypropyl)trimethoxysilane or hydrolyzed (3-glycidyloxypropyl)trimethoxysilane.

7. The composition of claim 6 , further defined as comprising the following epoxy monomers: trimethylol ethane triglycidyl ether and 3′,4′-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, and said hydroxylated epoxy monomer is the sorbitol polyglycidyl ether of formula:

8. The composition of claim 1 , further comprising at least one absorbing dye.

9. The composition of claim 8 , wherein the absorbing dye at least partially inhibits the transmission of light in at least one selected wavelength range between 380 and 1400 nm.

10. A method of preparing an optical article, comprising:
a) coating an optical substrate with the heat-curable coating composition of claim 1 ; and
b) curing the resulting coating with heat.

11. The method of claim 10 , wherein coating an optical substrate comprises spin-coating, spray-coating, 3D printing, roll-to-roll coating, or inkjet printing.

12. The method of claim 10 , wherein the resulting coating is heated to a temperature between 60° C. and 140° C. to form a tack-free or completely cured coating.

13. An optical article having at least one main surface comprising a coating obtained by depositing on an optical substrate and curing a composition according to the method of claim 10 , wherein said coating, following at least 40 hours of exposure to full spectrum sunlight, exhibits an adhesion of at least 96% to said optical substrate when tested according to ISTM 02-010.

14. The optical article of claim 13 , wherein the optical substrate comprises a thermoset material or hard coated polycarbonate lens.

15. A heat-curable coating composition, comprising:
a) 20-40% by weight as compared to the total weight of the composition of at least one epoxy monomer comprising two or three epoxy groups, wherein the at least one epoxy monomer does not include hydrolyzable groups directly linked to a silicon atom and comprises trimethylol ethane triglycidyl ether and 3′,4′-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate;
b) 10-25% by weight as compared to the total weight of the composition of at least one hydroxylated epoxy monomer comprising at least three epoxy groups and one to three hydroxyl groups, wherein the hydroxylated epoxy monomer does not include hydrolyzable groups directly linked to a silicon atom;
c) at least one UV absorber comprising a hydroxyphenyl benzotriazole or hydroxyphenyl triazine; and
d) at least one epoxy ring-opening catalyst.

Assignees

• Essilor Int

Inventors

• Zheng Haipeng
• Thai Christopher

Classifications

• G02B1/04 Primary

  made of organic materials, e.g. plastics (G02B1/08 takes precedence) · CPC title

• C08G59/38

  together with di-epoxy compounds · CPC title

• C08G59/70

  Chelates · CPC title

• C09D163/00

  Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins · CPC title

• G02C7/10

  Filters, e.g. for facilitating adaptation of the eyes to the dark; Sunglasses · CPC title