Enzymatic textile bleach-whitening methods

Abstract

A method for bleach-whitening of synthetic textile material is provided comprising contacting said textile material with (a) an enzymatic textile bleaching composition comprising (i) a perhydrolase enzyme, (ii) an ester substrate for said perhydrolase enzyme, (iii) a hydrogen peroxide source, (iv) a surfactant and/or an emulsifier, (v) a peroxide stabilizer, (vi) a sequestering agent, (vii) a buffer which maintains a pH of about 6 to about 8, and (b) at least one fluorescent whitening agent, and, optionally, (c) at least one acid or disperse shading dye for shaded variations of white, for a length of time and under conditions suitable to permit measurable whitening of the textile material, thereby producing a bleached-whitened textile material.

1 . A method for bleach-whitening of synthetic textile material comprising contacting said textile material with
 (a) an enzymatic textile bleaching composition comprising   (i) a perhydrolase enzyme,   (ii) an ester substrate for said perhydrolase enzyme,   (iii) a hydrogen peroxide source,   (iv) a surfactant and/or an emulsifier,   (v) a peroxide stabilizer,   (vi) a sequestering agent,   (vii) a buffer which maintains a pH of about 6 to about 8, and   (b) at least one fluorescent whitening agent, and, optionally,   (c) at least one acid or disperse shading dye for shaded variations of white,   for a length of time and under conditions suitable to permit measurable whitening of the textile material, thereby producing a bleached-whitened textile material.   
     
     
         2 . A method according to  claim 1 , wherein said perhydrolase enzyme comprises the amino acid sequence set forth in SEQ ID NO:1 or a variant or homolog thereof. 
     
     
         3 . A method according to  claim 2 , wherein said perhydrolase enzyme is the S54V variant of SEQ ID NO:1. 
     
     
         4 . A method according to  claim 1 , wherein said perhydrolase enzyme comprises a perhydrolysis to hydrolysis ratio greater than 1. 
     
     
         5 . A method according to  claim 1 , wherein said ester substrate is selected from propylene glycol diacetate, ethylene glycol diacetate, glycerol triacetate, ethyl acetate, and glycerol tributyrate. 
     
     
         6 . A method according to  claim 1 , wherein said hydrogen peroxide source is hydrogen peroxide. 
     
     
         7 . A method according to  claim 1 , wherein said surfactant and/or emulsifier comprises a non-ionic surfactant, for example, wherein the non-ionic surfactant is a fatty alcohol ethoxylate or isotridecanol ethoxylate. 
     
     
         8 . A method according to  claim 1 , wherein said peroxide stabilizer is phosphonic acid. 
     
     
         9 . A method according to  claim 1 , wherein said sequestering agent is polyacrylic acid. 
     
     
         10 . A method according to  claim 1 , wherein the fluorescent whitening agent is selected from the group comprising:
 a distyryl biphenyl derivative of the formula   
       
         
           
           
               
               
           
         
         in which 
         M is hydrogen, lithium, sodium, potassium, ammonium or ammonium that is mono-, di-, tri- or tetra-substituted by C 1 -C 6  alkyl or C 2 -C 6  hydroxyalkyl which may be interrupted by an oxygen atom or a mixture thereof, and 
         R 1  and R 2  independently of one another are hydrogen, C 1 -C 6  alkyl, C 1 -C 6  alkoxy or halogen; 
         a triazolyl stilbene disulfonic acid derivative of the formula 
       
       
         
           
           
               
               
           
         
         in which 
         M is defined as given above; 
         a diamino stilbene derivative of the formula 
       
       
         
           
           
               
               
           
         
         in which 
         M is defined as given above, and 
         R 3  and R 4  independently of one another are C 1 -C 4  alkoxy, C 1 -C 4  alkylthio, substituted or unsubstituted amino or an N-heterocycle which may contain further heteroatoms; 
         a diphenyl pyrazoline derivative of the formula 
       
       
         
           
           
               
               
           
         
         in which 
         M is defined as given above, and 
         R 5  and R 6  independently of one another are hydrogen, C 1 -C 4  alkyl, C 1 -C 4  alkoxy or halogen; 
         a diphenyl pyrazoline derivative of the formula 
       
       
         
           
           
               
               
           
         
         in which 
         M is defined as given above; 
         a coumarine derivative of the formula 
       
       
         
           
           
               
               
           
         
         a benzoxazole derivative of the formula 
       
       
         
           
           
               
               
           
         
         in which 
         B is a radical of formula —CH═CH—, 2,5-thiophenylene or 1,4-naphthylene, and 
         R 7  and R 8  independently of one another are hydrogen, C 1 -C 4  alkyl, C 1 -C 4  alkoxy or halogen; and 
         a dicyanstyrylbenzene derivative of the formula 
       
       
         
           
           
               
               
           
         
       
     
     
         11 . A method according to  claim 1 , wherein the fluorescent whitening agent is selected from the group of a distyryl biphenyl derivative of the formula 
       
         
           
           
               
               
           
         
         in which 
         M is hydrogen, lithium, sodium, potassium, ammonium or ammonium that is mono-, di-, tri- or tetra-substituted by C 1 -C 6  alkyl or C 2 -C 6  hydroxyalkyl which may be interrupted by an oxygen atom or a mixture thereof; and 
         a triazolyl stilbene disulfonic acid derivative of the formula 
       
       
         
           
           
               
               
           
         
         in which 
         M is defined as given above. 
       
     
     
         12 . A method according to  claim 1 , further comprising hydrolyzing said hydrogen peroxide with a catalase enzyme after said bleached textile is produced. 
     
     
         13 . A method according to  claim 1 , wherein the liquor ratio is about 20:1 or 10:1. 
     
     
         14 . A method according to  claim 1 , wherein said method is performed in a process selected from a batch process, an exhaust process, and a discontinuous process. 
     
     
         15 . A method according to  claim 1 , wherein the textile material is contacted with the enzymatic textile bleaching composition at a bleaching temperature of about 60° C. to about 70° C. for a processing time of about 40 to about 60 minutes.