Tape comprising a hybrid binder for high voltage application

A process for preparing a tape, the process comprising:

• providing a material comprising mica, a separate solid support and a resin component Z, the resin component Z comprising:
• i. one or more, the same or different, groups of formula
• wherein R is an organic group comprising 2 to 40 carbon atoms;
• and
• ii. one or more groups comprising one ester group and one ethylenically unsaturated group;
• iii. one or more groups comprising two ester groups and one ethylenically unsaturated group;
• and
• bonding the material comprising mica and the solid support with the resin component Z to form a tape consisting essentially of said mica, said separate solid support, and said resin component Z,
• wherein the resin component Z has an acid value of not more than 25 mgKOH/g.

A process for preparing a treated substrate, the process comprising:

• wrapping a substrate comprising a metal with a tape to obtain a wrapped substrate, the tape consisting essentially of mica and a separate solid support;
• one or more of coating and impregnating the wrapped substrate with a composition, the composition comprising:
• A) a resin component comprising:
• one or more, the same or different, groups of formula
• wherein R is an organic group comprising 2 to 40 carbon atoms;
• ii. one or more groups comprising two ester groups and one ethylenically unsaturated group;
• and
• iii. one or more terminal or pendant groups comprising one ester group and one ethylenically unsaturated group;
• B) at least one reactive diluent comprising at least one ethylenically unsaturated polymerizable group and having a boiling point at atmospheric pressure higher than 200° C.;
• and
• C) an initiator for radical polymerization;
• and
• curing the composition to form a cured resin composition;
• wherein the cured resin composition has an acid value of not more than 25 mgKOH/g.