Indoline-Nitroxide Radical as Stabiliser and Inhibitor for Reaction Resins, Reaction Resins Containing Same and Use Thereof

Abstract

Use of a stable indole-nitroxide radical as a stabilizer and/or inhibitor for resin mixtures and reactive resin mortars is described on the basis of radically curable compounds. Resin mixtures and reactive resin mortars may be made stable in storage very effectively using the indole nitroxide radical and the pot life of mortar compositions can be adjusted in a targeted manner.

1 . 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 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; 
         R 1 , R 2 , R 3  and R 4  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, —OR 5 , —COOH, —COOR 6  or —CN; 
         R 3  and R 4 ═X, where X is O or NR 7  and 
         R 5 , R 6 , R 7  each represents an alkyl, alkenyl, aryl or aralkyl group. 
       
     
     
         2 . The method according to  claim 1 , wherein in formula (I) at least one of R 1  and R 2  denotes a group with a molecular weight greater than 15 and/or
 R 3  and R 4 ═X wherein X is defined as given above and/or   R 1  denotes an aryl moiety such as phenyl or mesityl and   R 2  denotes a C 1 -C 4  alkyl moiety such as methyl, ethyl, isopropyl, n-butyl, an aryl moiety such as phenyl, a benzyl or allyl moiety.   
     
     
         3 . The method according to  claim 2 , wherein the stable nitroxide radical is selected from compounds of general formula (II) 
       
         
           
           
               
               
           
         
         wherein 
         R 1 , R 2 , R 3 , R 4  are defined in  claim 1 ; 
         R 8  to R 11  may be the same or different and each denotes, independently of one another, water or a group as defined for R 1  to R 4 ; or R 8  and R 9  or R 9  and R 10  or R 10  and R 11  are joined together to form an aliphatic or aromatic cycle. 
       
     
     
         4 . The method according to  claim 3 , wherein the stable nitroxide radical is 2,3-dihydro-2,2-diphenyl-3-(phenylimino)-1H-indole-1-oxyl nitroxide. 
     
     
         5 . The method according to  claim 1 , 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. 
     
     
         6 . The method according to  claim 1 , wherein the reactive resin mortar contains at least one inorganic additive, selected from the group consisting of fillers, thickeners, thixotropy agents, nonreactive solvents, agents to improve flowability and wetting agents. 
     
     
         7 . The method according to  claim 6 , wherein the at least one inorganic additive is cement and/or quartz sand. 
     
     
         8 . A resin mixture comprising at least one radically curable compound, at least one reactive diluent and a stabilizer and/or inhibitor wherein the stabilizer and/or inhibitor is/are a stable nitroxide radical which 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; 
         R 1 , R 2 , R 3  and R 4  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, —OR 5 , —COOH, —COOR 6  or —CN; 
         R 3  and R 4 ═X, where X is O or NR 7  and 
         R 5 , R 6 , R 7  each represents an alkyl, alkenyl, aryl or aralkyl group. 
       
     
     
         9 . The resin mixture according to  claim 8 , wherein in formula (I) at least one of R 1  and R 2  denotes a group with the molecular weight greater than 15 and/or
 R 3  and R 4 ═X where X is defined as given above and/or   R 1  denotes an aryl moiety such as phenyl or mesityl and   R 2  denotes a C 1 -C 4  alkyl moiety such as methyl, ethyl, isopropyl, n-butyl, an aryl moiety such as phenyl, a benzyl moiety or an allyl moiety.   
     
     
         10 . The resin mixture according to  claim 9 , wherein the stable nitroxide radical is selected from compounds of general formula (II) 
       
         
           
           
               
               
           
         
         wherein 
         R 1 , R 2 , R 3 , R 4  are defined in  claim 1 ; 
         R 8  to R 11  may be the same or different and each denotes, independently of one another, water or a group as defined for R 1  to R 4 ; or R 8  and R 9  or R 9  and R 10  or R 10  and R 11  are joined together to form an aliphatic or aromatic cycle. 
       
     
     
         11 . The resin mixture according to  claim 8 , wherein the stabilizer and/or inhibitor is 2,3-dihydro-2,2-diphenyl-3-(phenylimino)-1H-indole-1-oxyl nitroxide. 
     
     
         12 . The resin mixture according to  claim 8 , wherein the stable nitroxide radical is present in an amount of 0.02 to 1 wt %, based on the resin mixture. 
     
     
         13 . The resin mixture according to  claim 8 , wherein the table nitroxide radical is present in an amount of 0.05 to 25 wt %, based on the resin mixture. 
     
     
         14 . The resin mixture according to  claim 8 , wherein the radically polymerizable compound is obtained by reaction of di- and/or higher functional isocyanate with suitable acryl compounds, optionally with the participation of hydroxy compounds containing at least two hydroxyl groups. 
     
     
         15 . The resin mixture according to  claim 8 , which also contains at least one accelerator for curing the radically curable compound. 
     
     
         16 . The reactive resin mortar containing a resin mixture according to  claim 8 . 
     
     
         17 . The reactive resin mortar according to  claim 16 , containing at least one inorganic additive selected from the group consisting of fillers, thickeners, thixotropy agents, nonreactive solvents, agents to improve flowability and wetting agents. 
     
     
         18 . The reactive resin mortar according to  claim 17 , wherein the at least one inorganic additive is cement and/or quartz sand. 
     
     
         19 . A multicomponent mortar system containing as the A component the reactive resin mortar according to  claim 16  and as the B component a hardener for the radically curable compound. 
     
     
         20 . The multicomponent mortar system according to  claim 19 , wherein the A component additionally contains a hydraulically setting or polycondensable inorganic compound in addition to the reactive resin mortar, and the B component also contains water in addition to the hardener. 
     
     
         21 . A method of chemical fastening comprising using the multicomponent mortar system according to  claim 19  as a binder for chemical fastening. 
     
     
         22 . The capsule or cartridge or film bag, comprising the multicomponent mortar system according to  claim 19 , wherein they comprise two or more separate chambers in which the reactive resin mortar and/or hardener is/are situated.