Indoline-nitroxide radical as stabilizer and inhibitor for reactive resins, reactive resins containing same and use of same

A method of stabilizing and/or inhibiting resin mixture or a reactive resin mixture comprising:

• using a stable nitroxide radical as a stabilizer and/or inhibitor for a resin mixture or a reactive resin mixture based on radically curable compounds,
• wherein the radically curable compound is obtained by reacting di- and/or higher functional isocyanates with suitable acryl compounds, optionally with the participation of hydroxy compounds containing at least two hydroxyl groups each, and
• wherein the stable nitroxide radical is selected from compounds of general formula (I)
• wherein
• A is a hydrocarbon group which form an aromatic, optionally substituted ring with the two carbon atoms to which it is bound, wherein the substituents may constitute one or more optionally substituted aromatic or aliphatic condensed rings;
• R1, R2, R3 and R4 may be the same or different and each denotes independently of the others a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or an aralkyl group, —OH, —OR5, —COOH, —COOR6 or —CN;
• R3 and R4 =X, where X is O or NR7 and
• R5, R6, R7 each represents an alkyl, alkenyl, aryl or aralkyl group.