INSULATING COMPOSITES FOR POWER TRANSMISSION AND DISTRIBUTION

1 . An insulating composite for power transmission and distribution comprising a continuous reinforcing fiber embedded in a thermoset resin, wherein the thermoset resin is a reaction product of a curable epoxy resin composition comprising (a) at least one bisphenol A-type epoxy resin, (b) at least one oxazolidone ring containing epoxy resin, and (c) at least one anhydride hardener and wherein the curable epoxy resin composition has a viscosity of 6,000 Millipascals·second or less at 25° C.

2 . The insulating composite of claim 1 , wherein the bisphenol A-type epoxy resin is a diglycidyl ether of bisphenol A.

3 . The insulating composite of claim 1 , wherein the oxazolidone ring containing epoxy resin is a reaction product of an aromatic epoxy resin and an isocyanate compound.

4 . The insulating composite of claim 1 , wherein the anhydride hardener is selected from methyltetrahydrophthalic anhydride (MTHPA); methyl hexahydrophathalic anhydride (MHHPA); methyl-(endo)-5-norbornene-2,3-dicarboxylic anhydride (METHPA); hexahydrophthalic anhydride (HHPA); tetrahydrophthalic anhydride (THPA); pyromellitic dianhydride; ciscyclopentanetetracarboxylic acid dianhydride; hemimellitic anhydride; trimellitic anhydride; naphthalene-1,8-dicarboxylic acid anhydride; phthalic anhydride; dichloromaleic anhydride; dodecenylsuccinic anhydride; glutaric anhydride; maletic anhydride; succinic anhydride; or mixtures thereof.

5 . The insulating composite of claim 1 , wherein the curable epoxy resin composition comprises from 60 to 95 weight percent of the bisphenol A-type epoxy resin and from 5 to 40 weight percent of the oxazolidone ring containing epoxy resin, based on the total weight of epoxy resins in the curable epoxy resin composition.

6 . The insulating composite of claim 1 , wherein the curable epoxy resin composition further comprises an additional epoxy resin selected from the group consisting of a phenol novolac epoxy resin and a cycloaliphatic epoxy resin.

7 . The insulating composite of claim 1 , wherein the curable epoxy resin composition further comprises at least one of a toughening agent, a mold release agent, a catalyst and a filler.

8 . The insulating composite of claim 1 , wherein the reinforcing fiber is a glass fiber.

9 . The insulating composite of claim 1 , wherein the insulating composite comprises from 70 to 85 weight percent of the reinforcing fiber, based on the total weight of the insulating composite.

10 . The insulating composite of claim 1 , wherein the reinforcing fiber is axially aligned in the longitudinal direction of the insulating composite.

11 . The insulating composite of claim 1 , wherein the insulating composite is in a shape of a rod.

12 . The insulating composite of claim 11 having a length of one meter or more.

13 . The insulating composite of claim 1 , wherein the insulating composite is in a form of a core that further comprises an outer sheathing around the insulating composite core.

14 . The insulating composite of claim 13 , wherein the sheathing is rubber.

15 . A pultrusion process for preparing an insulating composite, comprising pulling a continuous reinforcing fiber, contacting the reinforcing fiber with a curable epoxy resin composition and curing the curable epoxy resin composition, wherein the curable epoxy resin composition has a viscosity of 6000 Millipascals·Second or less at 25° C. and contains (a) at least one bisphenol A-type epoxy resin, (b) at least one oxazolidone ring containing epoxy resin, and (c) at least one anhydride hardener.