Photopolymerizable compositions used in electronics

• US 5,180,757 A
• Filed: 05/16/1991
• Issued: 01/19/1993
• Est. Priority Date: 12/16/1987
• Status: Expired due to Fees

• Current Assignee: Mlt/Micro-Lite Technology Corporation
• Original Assignee: Michael Lucey
• Inventors: Lucey, Michael
• Primary Examiner(s): McCamish, Marion E.
• Assistant Examiner(s): Chapman, Mark A.
• Application Number:
  US07/701,664
• Time in Patent Office: 614 Days
• Field of Search: 522/76, 522/77, 522/79, 522/81, 522/83, 522/103
• US Class Current: 522/76
• CPC Class Codes: C08F 290/08 on to polymers modified by introduction of unsaturated side groups
• 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: H01C 1/022 the housing or enclosure being openable or separable from the resistive element
• CPC Class Codes: H01G 2/12 Protection against corrosion H01G2/10 takes precedence
• CPC Class Codes: H01G 9/08 Housing; Encapsulation

Abstract

Actinic radiation curable composition suitable for use in coating electronic components and as a printing ink comprising as the essential components:

(a) a monomer selected from the group consisting of monofunctional vinyl monomers and multifunctional vinyl monomers; or

(b) a prepolymer selected from the group consisting of monofunctional vinyl polymers and multifunctional vinyl polymers;

(c) a photoinitiator;

(d) at least one filler; and

(e) at least one surface active agent having a molecular weight greater than or equal to about 227;

wherein one of the surface active agent or the filler has a pH greater than or equal to 7 and the other of the surface active agent or the filler has a pH less than or equal to 7 such that dispersion of the filler in the composition is enhanced and relative high loading of filler in the composition is obtainable;

(f) or at least two surface active agents having a molecular weight greater than or equal to about 227 wherein one of the surface active agents has a pH greater than or equal to 7 and the other surface active agent has a pH less than or equal to 7 wherein the basic surface active agent is used to disperse fillers whose pH is less than or equal to 7 and the acidic surface active agent is used to disperse fillers whose pH is greater than or equal to 7 such that dispersion of the fillers in the composition are enhanced, and relative high loading of fillers in the composition is obtainable.

Claims

1. Actinic radiation curable composition suitable for use in coating electronic components and as a printing ink comprising:

(a) only one of either a monomer selected from the group consisting of monofunctional vinyl monomers and multifunctional vinyl monomers or a prepolymer selected from the group consisting of monofunctional vinyl resins and multifunctional vinyl resins;

(b) a photoinitiator;

(c) a filler; and

(d) at least one surface active agent having a molecular weight greater than or equal to about 227;

wherein one of the surface active agent or the filler has a pH greater than or equal to 7 and the other of the surface active agent or the filler has a pH less than or equal to 7 such that dispersion of the filler in the composition is enhanced and relative high loading of filler in the composition is obtainable.

2. Actinic radiation curable composition according to claim 1 wherein the prepolymer is an aromatic epoxy acrylate.

3. Actinic radiation curable composition according to claim 2 wherein the aromatic epoxy acrylate is a diacrylate ester of bisphenol A epoxy.

4. Actinic radiation curable composition according to claim 1 wherein the monomer is trimethylol propane triacrylate and/or 1,6 hexanediol diacrylate.

5. Actinic radiation curable composition according to claim 1 wherein the monomer is dicyclopentenyl acrylate.

6. Actinic radiation curable composition according to claim 1 wherein the monomer is pentaerythritol triacrylate.

7. Actinic radiation curable composition according to claim 1 wherein the monomer is hydroxypropyl acrylate.

8. Actinic radiation curable composition according to claim 1 wherein the monomer is dimethylaminoethyl acrylate.

9. Actinic radiation curable composition according to claim 1 wherein the photoaccelerator is selected from the group of 2-isopropyl-thioxanthone, 2-2 dimethoxy-2, phenyl-acetophenone, 2 hydroxy-2 methyl-1 phenyl propan-1-one, ethyl p-(N,N-dimethylamino) benzoate, and 2-(dimethylamino) ethyl benzoate.

10. Actinic radiation curable composition according to claim 1 wherein the filler is calcium metasilicate, or titanium dioxide, or zinc sulfide.

11. Actinic radiation curable composition according to claim 1 wherein the filler is carbon black.

12. Actinic radiation curable composition according to claim 1 wherein the filler is an alloy of chromium/copper/manganese/molybdenum, or cobalt/chromium/aluminum, or chromium/cobalt/magnesium/aluminum, or chromium/iron/silicon, or nickel/tin/titanium.

13. Actinic radiation curable composition according to claim 1 wherein the filler is copper, or aluminum, or iron oxide, or silver, or gold, or palladium, or platinum, or iridium, or tin, or lead, or cobalt, or iron, or magnesium, or silicon, or nickel, or manganese, or chromium, or tungsten, or titanium.

14. Actinic radiation curable composition according to claim 1 wherein the composition contains at least one surface active agent.

15. Actinic radiation curable composition according to claim 14 wherein one surface active agent is an organic phosphate ester.

16. Actinic radiation curable composition according to claim 15 wherein the organic phosphate acid ester is selected from the group of nonyl nonoxynol-7-phosphate, nonyl nonoxynol-10-phosphate, nonyl nonoxynol-15-phosphate, nonoxynol-9-phosphate, nonoxynol-4-phosphate, trideceth-6-phosphate, trideceth-4-phosphate, trideceth-7-phosphate, polyoxyethylene lauryl ether phosphate, polyoxyethylene phenyl ether phosphate, isoamyl alcohol ethoxylated phosphate, polyoxyethylene butoxyethyl ether phosphate, and polyoxyethylene hexyl ether phosphate.

17. Actinic radiation curable composition according to claim 14 wherein one surface active agent is a quaternary ammonium salt.

18. Actinic radiation curable composition according to claim 17 wherein the quaternary ammonium salt is selected from the group of polypropoxyglycol methyl diethyl quaternary ammonium acetate, polypropoxyglycol methyl diethyl quaternary ammonium phosphate, and polypropoxyglycol methyl diethyl quaternary ammonium chloride.

19. Actinic radiation curable composition according to claim 14 wherein one surface active agent is an acrylic or methacrylic organic phosphate acid ester.

20. Actinic radiation curable composition according to claim 19 wherein the acrylic or methacrylic organic phosphate acid ester is selected from the group of vinyl (acrylic or methacrylic) polyaliphatic phosphoric acid, vinyl (acrylic or methacrylic) aromatic phosphoric acid, vinyl (acrylic or methacrylic) bisphenol A phosphoric acid, vinyl (acrylic or methacrylic) polyethoxy phosphoric acid, and vinyl (acrylic methacrylic) polypropoxy phosphoric acid.

21. Actinic radiation curable composition according to claim 14 wherein one surface active agent is an organic acid and/or alcohol.

22. Actinic radiation curable composition according to claim 20 wherein the organic acid is selected from the group of oleic acid, palmitic acid, stearic acid, fish oil, linoleic acid, carboxylic acids, oleoyl acids, and titanates.

23. Actinic radiation curable composition according to claim 14 wherein one surface active agent is an acrylic or methacrylic quaternary ammonium salt.

24. Actinic radiation curable composition according to claim 23 wherein the acrylic or methacrylic quaternary ammonium salt is selected from the group of 2-trimethyl ammonium ethylmethacrylate chloride, N-trimethylammonium propylmethacrylamide chloride, and 2-trimethylammoniumethyl acrylate chloride.

25. Actinic radiation curable composition according to claim 14 wherein one surface active agent is an acrylic or methacrylic organic acid.

26. Actinic radiation curable composition according to claim 25 wherein the acrylic or methacrylic organic acid is selected from the group of maleic mono acryloyloxyethylester, maleic mono methacryloyloxyethylester, phthalic mono methacryloyloxylester, methacrylic acid, and acrylic acid.

27. Actinic radiation curable composition according to claim 1 wherein the filler used has been precoated with a surface active agent.

28. Actinic radiation curable composition according to claim 1 wherein the filler used has not been precoated with a surface active agent.

29. Actinic radiation curable composition according to claim 1 wherein the precoated filler is calcium metasilicate and the surface active agent is a silane.

30. Actinic radiation curable composition according to claim 29 wherein the silane is methacryloxypropyltrimethoxysilane.

31. Actinic radiation curable composition according to claim 1 wherein the precoated filler is calcium metasilicate and the surface active agent is an organic phosphate ester.

32. Actinic radiation curable composition according to claim 1 wherein the precoated filler is calcium metasilicate and the surface active agent is an acrylic or methacrylic organic phosphate acid ester.

33. Actinic radiation curable composition according to claim 1 wherein the filler is calcium metasilicate and the surface active agent is an organic acid and/or alcohol.

34. Actinic radiation curable composition according to claim 1 wherein the filler is calcium metasilicate and the surface active agent is an acrylic or methacrylic organic acid and/or alcohol.

35. Actinic radiation curable composition according to claim 1 wherein the filler is carbon black and the surface active agent is an acrylic or methacrylic quaternary ammonium salt and/or alcohol.

36. Actinic radiation curable composition according to claim 1 wherein the filler is carbon black and the surface active agent is a quaternary ammonium salt and/or alcohol.

37. Actinic radiation curable composition according to claim 1 wherein the filler is a metal alloy of cobalt/chromium/aluminum, or chromium/cobalt/magnesium/aluminum, or chromium/iron/silicon, or nickel/tin/titanium, and the surface active agent is a quaternary ammonium salt and/or alcohol.

38. Actinic radiation curable composition according to claim 1 wherein the filler is a metal alloy of cobalt/chromium/aluminum, of chromium/cobalt/magnesium/aluminum, or chromium/iron/silicon, or nickel/tin/titanium, and the surface active agent is an acrylic or methacrylic quaternary ammonium salt and/or alcohol.

39. Actinic radiation curable composition according to claim 1 wherein the filler is a metal of copper, or palladium, or platinum, or nickel, or tantalum, or molybdenum, or iron, or silver, or gold, or tungsten, or boron, or iridium, or aluminum, or titanium and the surface active agent is a quaternary ammonium salt and/or alcohol.

40. Actinic radiation curable composition according to claim 1 wherein the filler is a metal of copper, or pallatium, or platinum, or nickel, or tantalum, or molybdenum, or iron, or silver, or gold, or tungsten, or boron, or iridium, or aluminum, and the surface active agent is an acrylic or methacrylic quaternary ammonium salt and/or alcohol.

41. Actinic radiation curable composition according to claim 1 wherein the composition further comprises a flame retardant component.

42. Actinic radiation curable composition according to claim 1 wherein the composition further comprises an inhibitor component.

43. Actinic radiation curable composition according to claim 1 wherein the composition further includes a thixotropic agent.

44. Actinic radiation curable composition according to claim 43 wherein the thixotropic agent is fumed silica.

45. An electrical or electronic component coated with a composition according to the composition of claim 1.

46. Actinic radiation curable composition according to claim 1 wherein monofunctional vinyl monomers are selected from the group of monofunctional alpha, beta unsaturated carboxy monomers and wherein the multifunctional vinyl monomers are selected from the group of multifunctional alpha, beta unsaturated carboxy monomers.

47. Actinic radiation curable composition according to claim 1 wherein the prepolymer is between about 0 and about 70% by weight, the monomer is between about 1 and about 70% by weight, the photoinitiator is between about 1 and about 70% by weight, the filler is between about 25 and about 90% by weight and the surface active agent(s) is between about 0.5 and about 4% by weight of the composition.

48. Actinic radiation curable composition according to claim 1 wherein the prepolymer is between about 3 and about 20% by weight, the monomer is between about 3 and about 20% by weight, the photoinitiator is between about 2 and about 6% by weight, the filler is at least about 45% by weight, and the surface active agent(s) is between about 0.5 and about 4% by weight of the composition.

49. Actinic radiation curable composition according to claim 1 wherein the composition includes a first filler having a pH greater than 7, a second filler having a pH less than 7, a first surface active agent having a pH greater than 7 and a second surface active agent having a pH less than 7, the surface active agents having a molecular weight greater than or equal to about 227.

50. Actinic radiation curable composition according to claim 1 wherein the composition includes a first surface active agent having a pH greater than 7 and a second surface active agent having a pH less than 7, the surface active agents having a molecular weight greater than or equal to about 227.

51. Method of preparing an UV curable coating composition useful for coating electronic components comprising the following steps:

(a) selecting one of either a monomer selected from the group consisting of monofunctional vinyl ester monomers or a prepolymer selected from the group consisting of monofunctional vinyl ester resins and multifunctional vinyl ester resins;

(b) admixing with the monomer or prepolymer a filler;

(c) admixing with the mixture at least two surface active agents having a molecular weight greater than or equal to about 227 wherein one of the surface active agents has a pH greater than or equal to 7 and the other surface active agent has a pH less than or equal to 7 where the basic surface active agent disperses filler having a pH less than or equal to 7 and the acidic surface active agent disperses filler having a pH greater than or equal to 7; and

(d) admixing with the mixture a photoinitiator for polymerizing the monomer or prepolymer.

52. Method according to claim 51 wherein the filler has been pretreated with a surface active agent.

53. Method according to claim 51 wherein the filler has not been pretreated with a surface active agent.

54. Improved composition capable of being UV cured and suitable for use as a printing ink comprising:

(a) only one of either a monomer selected from the group consisting of monofunctional vinyl ester monomers selected from the group consisting of acrylate and methacrylate monomers, and multifunctional vinyl ester monomers selected from the group consisting of acrylate and methacrylate monomers or a prepolymer selected from the group consisting of monofunctional vinyl ester resins and multifunctional ester resins;

(b) a photoinitiator;

(c) a pigment; and

(d) at least one surface active agent having a molecular weight greater than or equal to about 227;

wherein one of the surface active agent or the pigment has a pH greater than or equal to 7 and the other of the surface active agent or pigment has a pH less than or equal to 7.

55. A process for preparing a cured coating layer on an electrical component comprising the steps of:

,

(a) preparing a coating composition comprising;

(1) only one of a monomer selected from the group consisting of monofunctional vinyl ester monomers selected from the group consisting of acrylate and methacrylate monomers, and multifunctional vinyl ester monomers selected from the group consisting of acrylate and methacrylate monomers;

or a prepolymer selected from the group consisting of monofunctional ester resins and multifunctional ester resins;

(2) a photoinitiator;

(3) a filler; and

(4) at least one surface active agent having a molecular weight greater than or equal to about 227;

wherein one of the surface active agent or the filler has a pH greater than or equal to 7 and the other of the surface active agent or the filler has a pH less than or equal to 7 such that the dispersion of the filler in the composition is enhanced and relative high loading of filler in the composition is obtainable;

(b) coating a desired electrical component with the said composition; and

(c) exposing the coating to actinic radiation at a wavelength within the ultraviolet and visible spectral regions or electron beam irradiation and for a period of time sufficient to cure the coating.

56. Process according to claim 55 wherein the cured coating is subjected to a post heat treatment at a suitable temperature and for a suitable period of time to complete the cure of the polymeric coating.

57. Actinic radiation curable composition suitable for use in coating electronic components and as a printing ink comprising:

(a) only one of either a monomer selected from the group consisting of monofunctional vinyl monomers and multifunctional vinyl monomers or a prepolymer selected from the group consisting of monofunctional vinyl resins and multifunctional vinyl resins;

(b) a photoinitiator;

(c) a first filler having a pH of 7 and a second filler having a pH greater than 7; and

(d) a first surface active agent having a pH greater than or equal to 7 and a second surface active agent having a pH less than 7 such that dispersion of the filler in the composition is enhanced and relative high loading of filler in the composition is obtainable, the surface active agents having a molecular weight greater than or equal to about 227.

58. Actinic radiation curable composition suitable for use in coating electronic components and as a printing ink comprising:

(a) a monomer selected from the group consisting of monofunctional vinyl monomers and multifunctional vinyl monomers;

(b) a prepolymer selected from the group consisting of monofunctional vinyl resins and multifunctional vinyl resins;

(c) a photoinitiator;

(d) a filler; and

(e) a first surface active agent having a pH greater than 7 and a second surface active agent having a pH less than 7 such that dispersion of the filler in the composition is enhanced and relative high loading of filler in the composition is obtainable, the surface active agents having a molecular weight greater than or equal to about 227.

59. Actinic radiation curable composition according to claim 58 wherein the composition includes a first filler having a pH greater than 7 and a second filler having a pH less than 7.

60. Actinic radiation curable composition suitable for use in coating electronic components and as a printing ink comprising:

(a) a monomer selected from the group consisting of monofunctional vinyl monomers and multifunctional vinyl monomers;

(b) a prepolymer selected from the group consisting of monofunctional vinyl resins and multifunctional vinyl resins;

(c) a photoinitiator;

(d) a first filler having a pH of 7 and a second filler having a pH greater than 7; and

(e) a first surface active agent having a pH greater than or equal to 7 and a second surface active agent having a pH less than 7 such that dispersion of the filler in the composition is enhanced and relative high loading of filler in the composition is obtainable, the surface active agents having a molecular weight greater than or equal to about 227.

61. Actinic radiation curable composition suitable for use in coating electronic components and as a printing ink comprising:

(a) only one of either a monomer selected from the group consisting of monofunctional vinyl monomers and multifunctional vinyl monomers or a prepolymer selected from the group consisting of monofunctional vinyl resins and multifunctional vinyl resins;

(b) a photoinitiator;

(c) a filler; and

(d) one surface active agent having a molecular weight greater than or equal to about 227;

wherein one of the surface active agent or the filler has a pH greater than or equal to 7 and the other of the surface active agent or the filler has a pH less than or equal to 7 such that dispersion of the filler in the composition is enhanced and relative high loading of filler in the composition is obtainable.

62. Actinic radiation curable composition suitable for use in coating electronic components and as a printing ink comprising:

(a) a monomer selected from the group consisting of monofunctional vinyl monomers and multifunctional vinyl monomers;

(b) a prepolymer selected from the group consisting of monofunctional vinyl resins and multifunctional vinyl resins;

(c) a photoinitiator;

(d) a filler; and

(e) one surface active agent having a molecular weight greater than or equal to about 227;

wherein one of the surface active agent or the filler has a pH greater than or equal to 7 and the other of the surface active agent or the filler has a pH less than or equal to 7 such that dispersion of the filler in the composition is enhanced and relative high loading of filler in the composition is obtainable.