CURABLE EPOXY RESIN COMPOSITION

• US 20100018750A1
• Filed: 10/02/2009
• Published: 01/28/2010
• Est. Priority Date: 04/03/2007
• Status: Abandoned Application

• Current Assignee: ABB Research Ltd. (ABB Ltd.)
• Original Assignee: ABB Research Ltd. (ABB Ltd.)
• Inventors: Rocks, Jens, Arauzo, Francisco, Meier, Patrick, SCHAAL, Stephane, Ghoul, Cherif, Gonzalez, Patricia
• Application Number:
  US12/572,872
• Publication Number:
  US 20100018750A1
• Time in Patent Office: Days
• US Class Current: 174/137.B
• CPC Class Codes: C08G 59/226 Mixtures of di-epoxy compounds
• CPC Class Codes: C08G 59/42 Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof
• CPC Class Codes: C08G 59/62 Alcohols or phenols
• CPC Class Codes: H01B 3/40 epoxy resins

Abstract

A curable epoxy resin composition is provided. The composition includes at least one diglycidyl ether of bisphenol A (DGEBA) and at least one diglycidyl ether of bisphenol F (DGEBF) as epoxy resins, in which the weight ratio of DGEBA:DGEBF is within the range of about 15:85 to 45:55; (ii) an anhydride hardener; (iii) and at least one plasticizer. The composition can additionally include a catalyst, at least one filler material and/or further additives. The dynamic complex viscosity value (η*) of the composition is within the range of 0.1 to 20 Pa·s. The present disclosure also provides a process for making the composition and electrical articles including an electrical insulation system made from the composition.

Claims

1. A curable epoxy resin composition, wherein said composition comprises:

(i) at least one diglycidyl ether of bisphenol A (DGEBA) and at least one diglycidyl ether of bisphenol F (DGEBF) as epoxy resins, wherein the weight ratio of DGEBA;

DGEBF is within the range of about 15;

85 to 45;

55;

(ii) an anhydride hardener; and

(iii) at least one plasticizer;

wherein the dynamic complex viscosity value (q*) of said composition is within the range of 0.1 to 20 Pa·

s, measured according to the ISO standard 6721-10.

2. The composition according to claim 1, wherein the weight ratio of DGEBA:

DGEBF is within the range of 20;

80 to 40;

60.

3. The composition according to claim 1, wherein the anhydride hardener is selected from the group consisting of:

maleic anhydride, methyltetrahydrophtalic anhydride, methyl-4-endomethylene tetrahydrophtalic anhydride, hexahydrophtalic anhydride, tetrahydrophtalic anhydride, and dodecenyl succinic anhydride.

4. The composition according to claim 1, wherein the plasticizer is selected from the group consisting of aromatic diols, aliphatic monomeric diols, aliphatic polymeric diols, and a mixture thereof.

5. The composition according to claim 4, wherein the plasticizer is present in an amount of from 5% to 50% by weight, calculated to the weight of the sum of the DGEBA and the DGEBF.

6. The composition according to claim 4, comprising an aromatic and an aliphatic diol having a weight ratio within the range of 80:

20 to 20;

80.

7. The composition according to claim 1, wherein the composition comprises a catalyst constituted by a 1-substituted imidazole and/or N,N-di-methylbenzylamine.

8. The composition according to claim 1, wherein the composition comprises a catalyst present in an amount of less than 5% by weight, calculated to the total weight of the DGEBA and DGEBF.

9. The composition according to claim 1, wherein the dynamic complex viscosity value (η

*) of the composition is within the range of 0.2 to 10 Pa·

s.

10. The composition according to claim 1, wherein the composition comprises at least one filler material constituting a mineral filler.

11. The composition according to claim 10, wherein a compound or mixture of the filler has an average grain size in the range of 1.0 μ

m to 2000 μ

m, and are present in an amount of 50% to 80% by weight, calculated to the total weight of the insulation composition.

12. The composition according to claim 1, wherein said composition comprises additives selected from the group consisting of hydrophobic compounds, elastomers, pigments, dyes and stabilizers.

13. The composition according to claim 1, wherein said composition is, in percentage by weight, comprised of 7.4 to 33.3% of the sum of the DGEBA+DGEBF, 2.9 to 40% of the anhydride hardener, 0.04 to 1.7% of a catalyst, 0.4 to 15% of the at least one plasticizer, and 50-80% of a filler.

14. A process for making a shaped article using a composition according to claim 1, comprising the steps of:

(a) preheating a curable liquid epoxy resin composition comprising (i) at least one diglycidyl ether of bisphenol A (DGEBA) and at least one diglycidyl ether of bisphenol F (DGEBF) as epoxy resins, (ii) an anhydride hardener; and

(iii) at least one plasticizer, wherein the weight ratio of DGEBA;

DGEBF is within the range of about 15;

85 to 45;

55, and the dynamic complex viscosity value (η

*) of said composition is within the range of 0.1 to 20 Pa·

s;

(b) transferring said composition into a pre-heated mold; and

(c) curing said composition at an elevated temperature for a time sufficient to obtain a shaped article with an infusible cross-linked structure.

15. An electrical article including an electrical insulation system constituted by said composition according to claim 1.

16. The composition according to claim 1, wherein the at least one plasticizer is a diol.

17. The composition according to claim 16, wherein the diol is solid at room temperature.

18. The composition according to claim 1, comprising:

a catalyst, at least one filler material and additives.

19. The composition according to claim 2, wherein the weight ratio of DGEBA DGEBF is within a range of 25:

75 to 35;

65.

20. The composition according to claim 1, wherein the anhydride hardener comprises methyltetrahydrophtalic anhydride (MTHPA).

21. The composition according to claim 4, wherein the plasticizer is selected from the group consisting of bisphenol A, bisphenol F, polyethylene glycols, polypropylene glycols, neopentyl glycol, and a mixture thereof.

22. The composition according to claim 4, wherein the plasticizer is selected from the group consisting of bisphenol A, bisphenol F, neopentyl glycol, and a mixture thereof.

23. The composition according to claim 5, wherein the plasticizer is present in an amount of from 10% to 45% by weight, calculated to the weight of the sum of the DGEBA and the DGEBF.

24. The composition according to claim 5, comprising an aromatic and an aliphatic diol having a weight ratio within the range of 80:

20 to 20;

80.

25. The composition according to claim 7, wherein the catalyst is a 1-alkyl imidazole which is substituted in the 2-position.

26. The composition according to claim 7, wherein the catalyst is 1-methyl imidazole or 1-isopropyl-2-methyl imidazole and/or 1-methyl imidazole.

27. The composition according to claim 7, wherein the catalyst is present in an amount of less than 5% by weight, calculated to the total weight of the DGEBA and DGEBF.

28. The composition according to claim 7, wherein the catalyst is present in an amount within the range of 0.01% to 2.5% by weight, calculated to the total weight of the DGEBA and DGEBF.

29. The composition according to claim 7, wherein the catalyst is present in an amount within the range of 0.05% to 1% by weight, calculated to the total weight of the DGEBA and DGEBF.

30. The composition according to claim 8, wherein the catalyst is present in an amount within the range of 0.01% to 2.5% by weight, calculated to the total weight of the DGEBA and DGEBF.

31. The composition according to claim 8, wherein the catalyst is present in an amount within the range of 0.05% to 1% by weight, calculated to the total weight of the DGEBA and DGEBF.

32. The composition according to claim 1, wherein the dynamic complex viscosity value (η

*) of the composition is within the range of 0.5 to 2.0 Pa·

s.

33. The composition according to claim 1, wherein the dynamic complex viscosity value (η

*) of the composition is about 1.0 Pa·

s.

34. The composition according to claim 10, wherein the filler is selected from the group consisting of silicon oxides, aluminum oxides, titanium oxides, silicates, zinc oxide, sodium/potassium silicates and silicon aluminosilicates.

35. The composition according to claim 34, wherein the silicates are selected from the group consisting of silicon oxides, aluminum oxides and hydroxides.

36. The composition according to claim 10, wherein the filler is surface treated.

37. The composition according to claim 10, wherein a compound or mixture of the filler has an average grain size in the range of from 5 μ

m to 500 μ

m, and are present in an amount of 55% to about 75% by weight, calculated to the total weight of the insulation composition.

38. The composition according to claim 10, wherein a compound or mixture of the filler has an average grain size in the 5 μ

m to 100 μ

m, and are present in an amount of about 60% to about 70% by weight, calculated to the total weight of the insulation composition.

39. The composition according to claim 12, wherein the hydrophobic compounds comprise a polysiloxane or a mixture of polysiloxanes.

40. The composition according to claim 11, wherein said composition is, in percentage by weight, comprised of 7.4 to 33.3% of the sum of the DGEBA+DGEBF, 2.9 to 40% of the anhydride hardener, 0.04 to 1.7% of a catalyst, 0.4 to 15% of the at least one plasticizer, and 50-80% of the filler.

41. The process according to claim 14, wherein the at least one plasticizer is a diol.

42. The process according to claim 41, wherein the diol is solid at room temperature.

43. The process according to claim 14, wherein composition includes a catalyst, at least one filler material, and additives.

44. The process according to claim 14, comprising post curing the obtained shaped article for approximately ten hours at a temperature of approximately 140°

C.

45. The electrical article according to claim 15, comprising a dry-type trans-former including cast coils.

46. The electrical article according to claim 45, wherein the dry-type transformer is a vacuum cast dry distribution transformer having a resin structure that contains electrical conductors.

47. The electrical article according to claim 15, wherein the insulation system includes insulation selected from the group consisting of a high-voltage insulation for indoor use, composite and cap-type insulators, base insulators in a medium-voltage sector, insulators associated with outdoor power switches.

48. The electrical article according to claim 15, comprising a device selected from the group consisting of a measuring transducer, a leadthrough, and an overvoltage protector, a power switch, a coating material for a semiconductor element, and an element to impregnate electrical components.