Abstract: A coating process for electrical steel sheets using a varnish composition includes: a) applying a varnish composition coating layer onto the surface of an electrical steel sheet. The varnish composition comprises (A) about 1 to about 95 wt % of a resin comprising nucleophilic groups chosen from OH, NHR, SH, carboxylate and CH-acidic groups, and electrophilic groups which can react with the nucleophilic groups, wherein the resin is capable of transacylation in its main chain and/or side chain(s), (B) about 5 to about 75 wt % of an organic solvent and/or water, (C) 0 to about 40 wt % of a resin different from (A), (D) 0 to about 10 wt % of a customary additive, (E) 0 to about 40 wt % of a pigment, filler and/or nano-scaled particle and/or monomeric and/or polymeric element-organic compound, wherein the wt % is based on the total weight of the varnish composition; b) curing the applied coating layer.

Abstract: The invention provides a coating process for electrical steel sheet using a varnish composition, comprising the steps of a) applying at least one coating layer of a varnish composition onto the surface of the electrical steel sheet wherein the varnish composition comprises (A) 1 to 95 wt % of at least one resin comprising nucleophilic groups selected from the group consisting of OH, NHR, SH, carboxylate and CH-acidic groups, and electrophilic groups which can react with the above mentioned nucleophilic groups, wherein the resin is capable of transacylation in its main chain and/or side chain(s), (B) 5 to 75 wt % of at least one organic solvent and/or water, (C) 0 to 40 wt % of at least one resin different from (A), (D) 0 to 10 wt % of at least one customary additive, (E) 0 to 40 wt % of at least one pigment, filler and/or nano-scaled particle and/or monomeric and/or polymeric element-organic compound, wherein the wt % based on the total weight of the varnish composition.

Abstract: A binder comprising a block polymer of blocks A and B and at least one of the blocks of C and D or E and F. The blocks are formed from: A monocarboxylic acids having 15 to 50 carbon atoms, B polyisocyanates having at least two isocyanate groups, C polycarboxylic acids having at least two carboxyl and/or anhydride groups, D polyisocyanates having at least two isocyanate groups, E polyalcohols having at least two hydroxyl groups, and F polyisocyanates having at least two isocyanate groups. The composition of the block polymer has the following composition: (f+g)/h=0.5 to 1.0, i/(h−f−g)=2.0 to 25 and a/(c+e)=0.1 to 1.0, where a, c and e=total moles of A, C and E; f=total equivalents of hydroxyl groups, g=total equivalents of carboxyl and anhydride groups, h=total equivalents of isocyanate groups and I=total moles of A to F.