Multi-component system for modifying, degrading or bleaching lignin, lignin-containing materials or similar substances and processes for its use

Abstract

Multi-component system for modifying, degrading or bleaching lignin, lignin-containing materials or similar substances, includes (a) if appropriate at least one oxidation catalyst; (b) at least one suitable oxidizing agent; and (c) at least one mediator, wherein the mediator is chosen from the group consisting of N-aryl-N-hydroxyamides.

What is claimed is:  
     
         1 . A multi-component system for modifying, degrading or bleaching lignin, or lignin-containing materials, comprising 
 (a) if appropriate at least one oxidation catalyst;    (b) at least one oxidizing agent; and    (c) at least one mediator, wherein the mediator is an N-aryl-N-hydroxyamide.    
     
     
         2 . A multi-component system as claimed in    claim 1   , wherein 
 the at least one mediator of (c) is    an N-aryl-N-hydroxyamide selected from the group consisting of the formula (I), the formula (II) or the formula (III)  
                 
   and salts, ethers or esters thereof, wherein    A is a monovalent homoaromatic or heteroaromatic mononuclear or dinuclear radical and    D is a divalent homoaromatic or heteroaromatic mononuclear or dinuclear radical, and    wherein these aromatics can be substituted by one or more identical or different radicals R 1  chosen from the group consisting of a halogen, hydroxyl, formyl, cyano, carbamoyl or carboxyl radical, an ester or salt of the carboxyl radical, a sulfono radical, an ester or salt of the sulfono radical, a sulfamoyl, nitro, nitroso, amino, phenyl, aryl-C 1 -C 5 -alkyl, C 1 -C 12 -alkyl, C 1 -C 5 -alkoxy, C 1 -C 10 -carbonyl, carbonyl-C 1 -C 6 -alkyl, phospho, phosphono or phosphono-oxy radical and an ester or salt of the phosphonooxy radical, and    where carbamoyl, sulfamoyl, amino and phenyl radicals can be unsubstituted or monosubstituted or polysubstituted by a radical R 2  and the aryl-C 1 -C 5 -alkyl, C 1 -C 12 -alkyl, C 1 -C 5 -alkoxy, C 1 -C 10 -carbonyl and carbonyl-C 1 -C 6 -alkyl radicals can be saturated or unsaturated, branched or unbranched and can be monosubstituted or polysubstituted by a radical R 2 , wherein    R 2  is identical or different and is a hydroxyl, formyl, cyano or carboxyl radical, an ester or salt of the carboxyl radical or a carbamoyl, sulfono, sulfamoyl, nitro, nitroso, amino, phenyl, C 1 -C 5 -alkyl, C 1 -C 5 -alkoxy or C 1 -C 5 -alkylcarbonyl radical, and in each case two radicals R 1  or R 2  can be linked in pairs via a bridge [—CR 3 R 4 ] m , where m is 0, 1, 2, 3 or 4, and    R 3  and R 4  are identical or different and are a carboxyl radical, an ester or salt of the carboxyl radical or a phenyl, C 1 -C 5 -alkyl, C 1 -C 5 -alkoxy or C 1 -C 5 -alkylcarbonyl radical, and    one or more non-adjacent groups [—CR 3 R 4 —] can be replaced by oxygen, sulfur or an imino radical which is optionally substituted by a C 1  to C 5  alkyl radical, and two adjacent groups [—CR 3 R 4 —] can be replaced by a group [—CR 3 ═CR 4 —] and    B is a monovalent acid radical, present in amidic form, of acids chosen from the group consisting of a carboxylic acid having up to 20 carbon atoms, carbonic acid, a half-ester of carbonic acid or of carbamic acid, sulfonic acid, phosphonic acid, phosphoric acid, a monoester of phosphoric acid or a diester of phosphoric acid and C is a divalent acid radical, present in amidic form, of acids chosen from the group consisting of monocarboxylic and dicarboxylic acids having up to 20 carbon atoms, carbonic acid, sulfonic acid, phosphonic acid, phosphoric acid or a monoester of phosphoric acid.    
     
     
         3 . A multi-component system as claimed in    claim 1   , comprising at least one oxidation catalyst (a).  
     
     
         4 . A multi-component system as claimed in    claim 3   , wherein the at least one oxidation catalyst of (a) is an enzyme.  
     
     
         5 . A multi-component system as claimed in    claim 4   , wherein the enzyme comprises laccase.  
     
     
         6 . A multi-component system as claimed in    claim 1   , 
 wherein the at least one oxidizing agent of (b) is selected from the group consisting of air, oxygen, ozone, H 2 O 2 , organic peroxides, peracids, peracetic acid, performic acid, persulfuric acid, pernitric acid, metachloroperoxybenzoic acid, perchloric acid, a perborate, a peracetate, a persulfate, a peroxide, an oxygen species and free radicals thereof, OH • , OOH • , singlet oxygen, superoxide (O 2   − ), ozonide or the dioxygenyl cation (O 2   + ), a dioxirane, a dioxetane and a Fremy radical.    
     
     
         7 . A multi-component system as claimed in    claim 1   , 
 wherein the at least one mediator of (c) is selected from the group consisting of N-hydroxyacetanilide, N-hydroxypivaloylanilide, N-hydroxyacrylanilide, N-hydroxybenzoylanilide, N-hydroxy-methylsulfonylanilide, N-hydroxy-N-phenyl-methylcarbamate, N-hydroxy-3-oxo-butyrylanilide, N-hydroxy-4-cyanoacetanilide, N-hydroxy-4-methoxyacetanilide, N-hydroxyphenacetin, N-hydroxy-2,3-dimethylacetanilide, N-hydroxy-2-methylacetanilide, N-hydroxy-4-methylacetanilide, 1-hydroxy-3,4-dihydroquinolin-(1H)-2-one, N,N′-dihydroxy-N,N′-diacetyl-1,3-phenylenediamine, N,N′-dihydroxy-succinic acid dianilide, N,N′-dihydroxy-maleic acid dianilide, N,N′-dihydroxy-oxalic acid dianilide, N,N′-dihydroxy-phosphoric acid dianilide, N-acetoxyacetanilide, N-hydroxymethyloxalylanilide and N-hydroxymaleic acid monoanilide.    
     
     
         8 . A multi-component system as claimed in    claim 1   , wherein the at least one mediator of (c) is N-hydroxyacetanilide.  
     
     
         9 . A process for the treatment of lignin comprising the steps of 
 providing an aqueous suspension of lignin-containing material; and    mixing with said aqueous suspension a multi-component system comprising as multi-components    (a) if appropriate at least one oxidation catalyst;    (b) at least one oxidizing agent; and    (c) at least one mediator, wherein the mediator is an N-aryl-N-hydroxyamide.    
     
     
         10 . The process of    claim 9   , comprising 
 simultaneously mixing said aqueous suspension with said multi-components of said multi-component system.    
     
     
         11 . The process of    claim 9   , comprising 
 mixing said multi-components in any sequence with said aqueous suspension.    
     
     
         12 . In a method for using a mediator for modifying, degrading or bleaching lignin, or lignin-containing materials, 
 the improvement which comprises utilizing the mediator (c) of    claim 1    for the modifying degrading or bleaching of lignin or lignin-containing materials.