Wrapping-Tape Insulating System for Electrical Machines, Use Therefor, and Electrical Machine

1 . A wrapping-tape insulating system produced by vacuum pressure impregnation, the system comprising

an insulating tape with at least one tape adhesive,

a tape accelerator mixed in the tape adhesive, and

an anhydride-free impregnating resin,

wherein the tape accelerator comprises an amino-imidazole, amino-imidazole derivatives and mixtures thereof, bonded via the amino function to an acrylate by aza-Michael addition.

2 . The wrapping-tape insulating system as claimed in claim 1 , wherein the amino-imidazole is selected from the group of imidazoles consisting of aminoalkyl-imidazoles, 1-(aminoalkyl)imidazole, 1H-2-aminoimidazole, 1H-2-(aminoalkyl)imidazole, 1H-4-aminoimidazole, 1H-4-(amino-alkyl)imidazole, 1H-5-aminoimidazole, 1H-5-(aminoalkyl)-imidazole, 1-(3-amino-propyl)imidazole,

1H-2-aminoimidazoles,

1H-2-aminomethylimidazole,

1H-2-aminoethylimidazole,

1H-2-aminopropylimidazole, and

1H-2-aminobenzimidazoles.

3 . The wrapping-tape insulating system as claimed in claim 1 , wherein the amino-imidazole is selected from the group of imidazoles derivable from the following structures I and II:

where

R 2 ═(—CH 2 —) n wherein n=1, 2, 3, . . . , 10,

R 3 ═(—CH 2 —) n wherein n=1, 2, 3, . . . , 10,

and R (identical and/or nonidentical)=methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, aryl, more particularly phenyl.

4 . The wrapping-tape insulating system as claimed in claim 1 , wherein the -acrylate is selected from the group of acrylates consisting of diacrylates, triacrylates, tetra-acrylates, penta-acrylates, hexa-acrylates and mixtures thereof.

5 . The wrapping-tape insulating system as claimed in claim 1 , wherein the acrylate is selected from the group of acrylates consisting of

trimethylolpropane triacrylate,

trimethylolpropane propoxylate triacrylate,

pentaerythritol tetraacrylate,

dipentaerythritol pentaacrylate/dipentaerythritol hexaacrylate and mixtures therof.

6 . The wrapping-tape insulating system as claimed in claim 1 , wherein the the tape adhesive comprises a copolyester or a diol and mixtures thereof.

7 . The wrapping-tape insulating system as claimed in claim 1 , wherein the tape accelerator is present in the insulating tape in an amount of less than about 10 wt %, based on the amount of impregnating resin.

8 . The wrapping-tape insulating system as claimed in claim 1 , wherein the tape adhesive is present in the insulating tape in an amount in the range from about 1 to about 30 wt %, based on the amount of impregnating resin.

9 . The wrapping-tape insulating system as claimed in claim 1 , wherein the tape accelerator is in the form of a compound having the following structure III:

10 . The wrapping-tape insulating system as claimed in claim 1 , wherein the tape accelerator is in the form of a compound whose structure is derived from at least one of the following parent structures IV, V and VI:

wherein

R=identical and/or nonidentical and ═H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl and/or mono-, di-, tri-, tetra-, pentasubstituted phenyl, wherein the substituents on the phenyl radical may in turn be identical or nonidentical and may have been selected from the following group:

R phenyl =alkyl (linear and branched), alkoxy, —F, —Cl, —Br, —I, aldehyde, ketone, acyl ester, acyl amide, phosphonic acid derivative and/or sulfonic acid derivative.

11 . The wrapping-tape insulating system as claimed in claim 1 , wherein the tape accelerator is in the form of a compound whose structure is derived from at least one of the following parent structures VII, VIII and IX:

wherein

R=identical and/or nonidentical and ═H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl and/or mono-, di-, tri-, tetra-, pentasubstituted phenyl, wherein the substituents on the phenyl radical may in turn be identical or nonidentical and may have been selected from the following group:

R phenyl =alkyl (linear and branched), alkoxy, —F, —Cl, —Br, —I, aldehyde, ketone, acyl ester, acyl amide, phosphonic acid derivative and/or sulfonic acid derivative.

12 . The wrapping-tape insulating system as claimed in claim 1 , wherein the tape accelerator is in the form of a compound whose structure is derived from at least one of the following parent structures X, XI and XII:

wherein

R=identical and/or nonidentical and ═H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl and/or mono-, di-, tri-, tetra-, pentasubstituted phenyl, wherein the substituents on the phenyl radical may in turn be identical or nonidentical and may have been selected from the following group:

R phenyl =alkyl (linear and branched), alkoxy, —F, —Cl, —Br, —I, aldehyde, ketone, acyl ester, acyl amide, phosphonic acid derivative and/or sulfonic acid derivative.

13 . The wrapping-tape insulating system as claimed in claim 1 , wherein the tape accelerator in the form of a compound whose structure is derived from the following parent structure XIII:

wherein

R 2 ═H and/or structure XIV

and/or structure XV

and/or structure XVI

wherein for structure XIII:

R=identical and/or nonidentical and

R═H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl and/or mono-, di-, tri-, tetra-, pentasubstituted phenyl,

wherein the substituents on the phenyl radical may in turn be identical or nonidentical and may have been selected from the following group:

R phenyl =alkyl (linear and branched), alkoxy, F, Cl, Br, I, aldehyde, ketone, acyl ester, acyl amide, phosphonic acid derivative and/or sulfonic acid derivative

R 2 as indicated in the structures XIV, XV and XVI.

14 - 15 . (canceled)

16 . A wrapping-tape insulating system produced by vacuum pressure impregnation, the system comprising:

an insulating tape, the insulating tape comprising

a tape adhesive selected from the group of tape adhesives selected from the group consisting of tricyclomethanedimethanol,trimethylolpropane,hydroxy-functional dendritic polymers,polycaprolactone triols, and polycaprolactone tetrols;

a tape accelerator mixed in the tape adhesive, the tape accelerator selected from the group consisting of 1H-2-aminoimidazoles, 1H-2-(aminoalkyl)imidazoles, and mixtures thereof covalently bonded via the amino function to an acrylate by aza-Michael addition, the acrylate selected from the group consisting of trimethylolpropane triacrylate, trimethylolpropane propoxylate triacrylate, pentaerythritol tetraacrylate,

dipentaerythritol pentaacrylate/dipentaerythritol hexaacrylate and mixtures thereof; and

an anhydride-free resin.

17 . The system as claimed in claim 16 , wherein the tape accelerator comprises 1,2-dimethylimidazole.

18 . The system as claimed in claim 16 , wherein the tape adhesive is oxirane group free.

19 . The system as claimed in claim 17 , wherein the tape adhesive is present in an amount of about 2 wt % of the anhydride-free resin.

20 . The system of claim 16 , wherein the tape accelerator has a vapor pressure of less than about 10 −4 at a temperature of about 50° C. to about 80° C.

21 . The system of claim 16 , wherein the tape accelerator has a glass transition temperature of about 140° C. or higher.

22 . A wrapping-tape insulating system comprising:

an insulating tape produced by vacuum pressure impregnation, the insulating tape comprising

an oxirane group free tape adhesive;

a tape accelerator mixed in the tape adhesive, the tape accelerator comprising an imidazole covalently bonded via the amino function to an acrylate by aza-Michael addition, the tape accelerator having a vapor pressure of less than about 10 −3 at a temperature of about 50° C. to about 80° C. and a glass transition temperature of about 140° C. or higher; and

an anhydride-free epoxy resin.

23 . The system of claim 22 , wherein the imidazole is selected from the group consisting of 1H-2-aminoimidazoles, 1H-2-(aminoalkyl)imidazoles, and mixtures thereof.