Ultraviolet radiation curable vehicle for ceramic colors, composition and method

• US 4,649,062 A
• Filed: 04/25/1985
• Issued: 03/10/1987
• Est. Priority Date: 01/05/1983
• Status: Expired due to Fees

• Current Assignee: Ciba-Geigy Corporation (Novartis Ag)
• Original Assignee: Ciba-Geigy Corporation (Novartis Ag)
• Inventors: Gatechair, Leslie R., Kosiorek, Raymond S.
• Primary Examiner(s): Bleutge, John C.
• Assistant Examiner(s): KOECKERT JR, ARTHUR
• Application Number:
  US06/727,184
• Time in Patent Office: 684 Days
• Field of Search: 522/14, 522/10, 522/81, 427/54.1, 427/125, 427/228
• US Class Current: 427/511
• CPC Class Codes: C08F 290/06 Polymers provided for in subclass C08G

Abstract

Vehicles for ultraviolet radiation-curable ceramic enamels comprise (a) acrylate- or methacrylate-modified oligomers; (b) acrylate or methacrylate monomers, the functionality of (a) and (b) being selected to provide desired film and firing characteristics; (c) a combination of photoinitiators to provide a balance of surface and through cure; and an inhibitor to enhance shelf life. Printing media comprising pigmented frits and the vehicles are described, as are methods for their application to heat-resistant substrates, especially glass.

Claims

1. An ultraviolet radiation curable vehicle for ceramic frits, said vehicle comprising

(a) not less than three polymerizable liquid oligomers, each containing acrylate or methacrylate functional end groups and selected from

(i) a difunctional- or trifunctional-polyester acrylate or methacrylate, a difunctional- or trifunctional-polyether acrylate or methacrylate, a difunctional- or trifunctional-polyester-polyether acrylate or methacrylate, a difunctional- or trifunctional-polyurethane acrylate or methacrylate or a mixture of any of the foregoing;

(ii) an at least tetrafunctional polyester-polyether acrylate or methacrylate; and

(iii) an epoxidized unsaturated fatty acid triglyceride acrylate or methacrylate;

the amount of (ii) being at least sufficient to increase solvent resistance of the cured vehicle and the amount of (iii) being at least sufficient to enhance the adhesion thereof to a substrate;

(b) not less than three polymerizable liquid monomers, each containing acrylic or methacrylic functional groups and selected from

(i) a monofunctional polyether acrylate or methacrylate;

(ii) at least one difunctional polyglycol acrylate or methacrylate; and

(iii) at least one trifunctional aliphatic triacrylate or trimethacrylate;

the ratios of (i), (ii) and (iii) being selected to provide an acrylate or methacrylate functionality of not less than 1 nor more than 3;

(c) an effective amount of a photoinitiator combination comprising

(i) a 2-phenyl acetophenone compound;

(ii) a substituted thioxanthone compound; and

(iii) an ester of an aminobenzoic acid, or a tertiary amine, the ratios of (i), (ii) and (iii) being selected to provide a balance of surface cure and through cure on ultraviolet exposure of films comprising said vehicle; and

(d) an amount of a polymerization inhibitor which is at least effective to retard polymerization of the vehicle in total darkness, but less than an amount which will significantly retard the rate of cure of said vehicle when exposed to ultraviolet light.

2. An ultraviolet radiation curable vehicle, as defined in claim 1, wherein the inhibitor component (d) comprises hydroquinone.

3. An ultraviolet radiation curable vehicle, as defined in claim 1, which also includes (e) a small, effective amount of flow promoter.

4. An ultraviolet radiation curable vehicle, as defined in claim 3, wherein the flow promoter (e) comprises a polymerized butene hydrocarbon.

5. An ultraviolet radiation curable composition for coating the surface of a heat-resistant substrate comprising

(1) 100 parts by weight of a vehicle as defined in claim 1, and

(2) from about 200 parts to about 550 parts by weight of a ceramic frit.

6. An ultraviolet radiation curable composition, as defined in claim 5, which also includes

(3) a small, but effective to enhance screen printability, amount of a solvent for the vehicle component of said composition.

7. An ultraviolet radiation curable composition, as defined in claim 6, wherein said solvent (3) comprises a liquid aromatic hydrocarbon mixture in which the major components are C₉ -C₁₀ aromatics.

8. An ultraviolet radiation curable vehicle, as defined in claim 3, which comprises

(a) 45 to 65 parts by weight of said oligomeric component;

(b) 30 to 40 parts by weight of said monomer component;

(c) 5 to 15 parts by weight of said photoinitiator component;

(d) 0.01 to 0.5 parts by weight of said inhibitor component; and

(e) to 0.2 to 2.0 parts by weight of said flow promoter component per 100 parts by weight of components (a) to (e), inclusive.

9. An ultraviolet radiation curable vehicle, as defined in claim 1, wherein component

(a)(i) comprises a difunctional- or trifunctional-acrylate containing polyester backbone units;

(a)(ii) comprises a tetrafunctional polyester-polyether acrylate;

(a)(iii) comprises an acrylated epoxylated linseed oil;

(b)(i) comprises ethoxyethoxyethyl acrylate;

(b)(ii) comprises a polyethyleneglycol diacrylate and tripropylene glycol diacrylate;

(b)(iii) comprises at least one aliphatic triacrylate;

(c)(i) comprises 2,2-dimethoxy-2-phenylacetophenone;

(c)(ii) comprises 2-isopropylthioxanthone;

(c)(iii) comprises ethyl 4-dimethylaminobenzoate; and

(d) comprises hydroquinone.

10. An ultraviolet radiation curable vehicle, as defined in claim 8, where flow promoter component (e) comprises a polybutene.

11. A process for coating a heat-resistant substrate selected from glass, metal and ceramic comprising

(1) applying a printing medium to the heat-resistant substrate, wherein the printing medium comprises a ceramic frit and a vehicle therefor, as defined in claim 5;

(2) curing the printing medium with ultraviolet radiation after it is applied to the substrate; and

(3) thereafter firing the substrate with the applied and cured printing medium at a temperature sufficient to burn off the vehicle and fuse the frit to the substrate.

12. A process for coating a heat-resistant substrate selected from glass, metal and ceramic comprising

(1) applying a solvent-containing printing medium to the heat-resistant substrate, wherein the printing medium comprises a ceramic frit and a vehicle therefor and a solvent, as defined in claim 6;

(2) curing the printing medium with ultraviolet radiation after it is applied to the substrate; and

(3) thereafter firing the substrate with the applied and cured printing medium at a temperature sufficient to burn off the vehicle and fuse the frit to the substrate.

13. A process for coating a heat-resistant substrate selected from glass, metal and ceramic comprising

(1A) applying a first printing medium to the heat-resistant substrate, wherein the printing medium comprises a low-melting ceramic frit, a conductive metal powder and a resinous vehicle and allowing the medium to cure in place;

(1B) applying a second printing medium to the heat-resistant substrate over the first printing medium, wherein the second printing medium comprises a ceramic frit and a vehicle therefor, as defined in claim 5;

(2) curing the second printing medium with ultraviolet radiation after it is applied to the substrate; and

(3) thereafter firing the substrate with the applied and cured printing media at a temperature sufficient to burn off the vehicles and fuse the frits to the substrate so as to provide an overprinted electrically conductive subsurface layer.