DIELECTRIC, RADIATION-CURABLE COATING COMPOSITIONS

• US 20020004537A1
• Filed: 05/07/1998
• Published: 01/10/2002
• Est. Priority Date: 10/30/1997
• Status: Active Grant

• Current Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Original Assignee: Dsm Nv
• Inventors: KRONGAUZ, VADIM V., HA, CHAU T.M., RAMPURIA, SANGEETA
• Granted Patent: US 6,506,814 B2
• Time in Patent Office: Days
• US Class Current: 522/90
• CPC Class Codes: C08F 290/067 Polyurethanes; Polyureas
• CPC Class Codes: C08F 290/08 on to polymers modified by introduction of unsaturated side groups
• CPC Class Codes: C08F 290/14 Polymers provided for in subclass C08G
• CPC Class Codes: C08F 290/147 Polyurethanes; Polyureas
• CPC Class Codes: C09D 4/06 Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond in combination with a macromolecular compound other than an unsaturated polymer of groups C09D159/00 - C09D187/00
• CPC Class Codes: C09J 4/06 Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond in combination with a macromolecular compound other than an unsaturated polymer of groups C09J159/00 - C09J187/00
• CPC Class Codes: G11B 7/26 Apparatus or processes specially adapted for the manufacture of record carriers
• CPC Class Codes: H01B 3/30 plastics; resins; waxes

Abstract

A UV-curable acrylate-thiol-ene insulating coating composition for electrical conductors, a method of manufacturing a UV-curable acrylate-thiol-ene insulating coating composition for electrical conductors. The insulating coating being of about 2.5 μm to about 500 μm thickness, which cured coating has a dielectric dissipation factor (60Hz, 24° C.) of lower than about 0.05.

Claims

1. An insulating coating for an electrical conductor having a cured coating of about 2.5 μ

m to about 500 μ

m thickness which coating has a dielectric dissipation factor (60 Hz, 24°

C.) of lower than about 0.05, said insulating coating being a radiation-cured coating formulated from a coating composition comprising;

(A) about 15 wt. % to about 80 wt. % of at least one UV or radiation-curable acrylate oligomer;

(B) about 3 wt. % to about 20 wt. % of at least one vinyl reactive diluent or ene reactive diluent;

(C) about 10 wt. % to about 80 wt. % of at least one acrylate monomer diluent;

(D) about 0.5 wt. % to about 10 wt. % of at least one thiol compound, and

(E) optionally at least one additional additive, wherein the pre-mixture ingredients correspond to the identity of radiation-curable composition components prior to mixture with other ingredients.

2. An insulating coating according to claim 1, wherein the at least one acrylate monomer diluent comprises isobornylacrylate.

3. An insulating coating according to claim 1, wherein the at least one vinyl reactive diluent is selected from the group consisting of N-vinylpyrrolidone and N-vinyl caprolactam.

4. An insulating coating according to claim 1, wherein the additional additives comprise at least one member selected from the group consisting of photoinitiators, stabilizers, chain transfer agents, plasticizers, light stabilizers, UV screening compounds, leveling agents, wetting agents and preservatives.

5. An insulating coating according to claim 1, wherein the at least one additional additive comprises at least one photoinitiator selected from the group consisting of mercaptobenzothiazoles, mercaptobenzooxazoles, benzophenones, acetophenone derivatives, benzoin alkyl ethers, benzil ketals, monoacylphosphine oxides and bisacylphosphine oxides.

6. An insulating coating according to claim 1, wherein the thiol compound comprises γ

-mercaptopropyl-trimethoxysilane.

7. An insulating coating according to claim 1, wherein said electrical conductor is made from a material selected from the group consisting of metals, ceramics, silicones and polymers.

8. An insulating coating according to claim 1, wherein said electrical conductor is a component of a device selected from the group consisting of semiconductors, printed circuit boards, capacitors, resistors, motors, coils, transformers, generators and electrical wiring systems.

9. An insulating coating according to claim 1, wherein said electrical conductor is made from a metallic material selected from the group consisting of iron, copper, aluminum and silver.

10. An insulating coating according to claim 1, wherein the cured coating has a dissipation factor at 60 Hz at 150°

C. of lower than about 0.5.

11. An insulating coating according to claim 1, wherein the cured coating is formulated from the coating composition which further comprises a photoinitiator.

12. An insulating coating according to claim 11, wherein the cured coating is a coating cured by irradiation with light with a wavelength between about 200 μ

m to about 700 μ

m, and the photoinitiator is present in an amount of about 1 wt. % to about 10 wt. % of the coating composition.

13. An insulating coating according to claim 1, wherein the cured coating is formulated from the coating composition which further comprises an adhesion promoter.

14. An insulating coating according to claim 13, wherein the adhesion promoter is an acid functional compound.

15. An insulating coating to claim 1, wherein the cured coating further comprises about 0.2 wt. % to about 5 wt. % of a pigment or a dye.

16. An insulating coating according to claim 1, wherein the cured coating has a thickness of about 10 μ

m to about 100 μ

m.

17. An insulating coating according to claim 1, wherein the cured coating has a dielectric constant lower than about 5.

18. An insulating coating according to claim 1, wherein the cured coating has a dielectric dissipation factor lower than about 0.05 (60 Hz, 24°

C.) after hot oil exposure (150°

C.)

19. An insulating coating according to claim 1, wherein said hydrocarbon backbone is fully saturated.

20. An insulating coating according to claim 1, wherein said coating has a dielectric dissipation factor (60 Hz, 140°

C.) of lower than about 1.0.

21. A method of manufacturing an insulating radiation-cured coating for an electrical conductor comprising the steps of:

(A) coating an electrical conductor with a radiation-curable coating composition, the coating composition being formulated from the following premixture ingredients;

(i) about 15 wt. % to about 80 wt. % of at least one UV or radiation-curable acrylate oligomer;

(ii) about 3 wt. % to about 20 wt. % of at least one vinyl reactive diluent or ene reactive diluent;

(iii) about 10 wt. % to about 80 wt. % of at least one acrylate monomer diluent;

(iv) about 0.5 wt. % to about 10 wt. % of at least one thiol compound, and

(v) optionally at least one additional additive,

wherein the pre-mixture ingredients correspond to the identity of radiation-curable composition components prior to mixture with other ingredients; and

(B) exposing the electrical conductor coated with said coating composition to an effective amount of radiation to sufficiently cure the coating composition to form an insulating radiation-cured coating on the electrical conductor, wherein said insulating radiation-cured coating has a dielectric dissipation factor at 60 Hz at 24°

C. of lower than about 0.05, a dissipation factor at 60 Hz at 150°

C. of lower than about 0.5, and an elongation at 25°

C. of a 25 μ

m thin coating of greater than about 50%.