Impregnation resin mixture
The invention relates to an impregnation resin mixture and to the use thereof. In one embodiment, an impregnation resin mixture includes a) at least one epoxide resin component selected from the group consisting of polyepoxides based on bisphenol A and/or F, and advancement resin produced therefrom, based on epoxidized halogenated bisphenols and/or epoxidized novolaks and/or polyepoxide esters based on phthalic acid, hexahydrophthalic acid, or based on terephthalic acid, epoxidized polyaddition products from dicyclopentadiene and phenol or cycloaliphatic compounds, b) as reactive diluents, 2 to 30 wt. % lactones with respect to the sum of the epoxy resin components, c) BCI3 and/or BCI3 complexes and/or a compound selected from the group of imidazoles and d) optionally additional additives, wherein the impregnation resin mixture does not contain any carboxylic acid anhydrides.
1. A process for producing an insulated electrical conductor, the process comprising:
(I) forming an insulation tape by applying a composition as adhesive between a nonconductive material and a reinforcement layer, the composition comprising:
a) at least one epoxy resin component or one novolac, wherein the novolac has a molar mass of 250 to 1000 g/mol;
b) BCl 3 , BCl 3 complexes, imidazole compounds, or combinations thereof; and
c) optionally further additives;
(II) winding the insulation tape around the electrical conductor; and
(III) impregnating the insulation tape wound around the electrical conductor with an impregnation resin mixture comprising the following constituents:
d) at least one epoxy resin component selected from polyepoxides based on bisphenol A, advancement resins produced therefrom, polyepoxides based on bisphenol F, advancement resins produced therefrom, polyepoxides based on epoxidized halogenated bisphenols, polyepoxides based on epoxidized novolacs, polyepoxy esters based on phthalic acid, polyepoxy esters based on hexahydrophthalic acid, polyepoxy esters based on terephthalic acid, epoxidized polyaddition products made of dicyclopentadiene and phenol, and epoxidized polyaddition products made of cycloaliphatic compounds;
e) 2 to 30% by weight of lactones, based on the entirety of the epoxy resin components, and
f) optionally further additives,
where the impregnation resin mixture and the composition of the insulation tape comprise no carboxylic anhydrides.
2. The process of claim 1 , wherein the impregnation in step (III) takes place in vacuo.
3. The process of claim 1 , wherein the non-conductive material is mica.
4. The process of claim 1 , wherein the reinforcement layer is composed of a woven fabric, a knitted fabric, a nonwoven web or a foil and is made of at least one of glass, rockwool, polyimide, polyester, and quartz.
5. The process of claim 1 , wherein the insulation tape comprises 5 to 20% by weight of the composition, based on total mass of the insulation tape.
6. The process of claim 1 , wherein the composition comprises 1 to 30% by weight of the BCl 3 , BCl 3 complexes, imidazole compounds, or combinations thereof, based on the weight of the at least one epoxy resin component or the novolac.
7. The process of claim 1 , wherein the composition further comprises
a) solvents or
b) coupling agents or
c) wetting agents.
8. The process of claim 1 , wherein the composition comprises
a) 50-90% by weight of the at least one epoxy resin component or the novolac,
b) 1-30% by weight of the BCl 3 , BCl 3 complexes, imidazole compounds, or combinations thereof, and
c) 0-49% by weight of further additives,
based on the total weight of all of the components of the composition.