Application of carbonyl compounds in the process of tanning hides

Abstract

The application of carbonyl compounds in the process of tanning hides, including the use of selected α-hydroxy ketones that present a general formula as (I) where R may be a linear or ramified alkyl group or even aromatic group and R 1 and R 2 may be hydrogen, linear or ramified alkyl or even aromatic, as, for example, R 1 ═R 2 ═H and R═CH 2 CH 3 or, preferentially, R 1 ═R 2 ═H and R═—CH 3 , or still, the use of selected β-hydroxyl ketones presenting a general formula s (II) where R may be a linear or ramified alkyl group or even aromatic group as, for example, R, R 1 and R 2 ═—CH 3 and R 3 ═H, preferentially R, R 2 and R 3 ═—CH 3 , and R 1 ═H. The application of carbonyl compounds in the process of tanning hides, with the possibility of using a water solution, in concentrations that may vary from 0.1 % till its pure state, that is, 100 %, or still, in mixtures with other organic compounds acting as dilutents.

I claim:  
     
         1 . A process of tanning hide characterized in that it comprises a step of contacting the hide with a member selected from the group consisting of: an α-hydroxy ketone of General Formula (I):  
       
         
           
           
               
               
           
         
       
       wherein R 1  is linear or ramified alkyl group or an aromatic group and R 1  and R 2  independently are hydrogen, a linear or ramified alkyl group or an aromatic group, and R 1  and R 2  are not concomitantly H,  
       and a β-hydroxy ketone of General Formula II:  
       
         
           
           
               
               
           
         
       
       wherein R is a linear or ramified alkyl group or an aromatic group and R 1  and R 2  and R 3  independently are hydrogen, a linear or ramified alkyl group or an aromatic group.  
     
     
         2 . A process according to  claim 1 , characterized in that it comprises a step of contacting said hide with the β-hydroxy ketone of formula (II).  
     
     
         3 . A process according to  claim 1 , characterized in that it comprises a step of contacting said hide with the α-hydroxy ketone of formula (I) wherein R═CH 2 CH 3  or CH 3  and wherein when R 2 ═H, R 3  is alkyl.  
     
     
         4 . A process according to  claim 2 , characterized in that it comprises the step of contacting said hide with the β-hydroxy ketone of general formula (II), wherein R is CH 3 , R 1  is H or CH 3 , R 2  is CH 3 , and R 3  is H or CH 3 .  
     
     
         5 . A process according to  claim 1 , wherein said β-hydroxy ketone is diacetone alcohol.  
     
     
         6 . A process according to  claim 1 , wherein the amount of said α- or β-hydroxy ketone ranges from about 0.1% to 100% by weight based on the total weight of said hide.  
     
     
         7 . A process according to  claim 1 , wherein said α- or β-hydroxy ketone is used (a) as such, (b) diluted in water, or (c) in mixtures with other organic compounds acting as diluents, with or without water.  
     
     
         8 . A process according to  claim 1 , wherein the concentration of said α- or β-hydroxy ketone ranges from about 0.1% to about 30% in weight based on the total weight of hide, and wherein said step of contacting the hide with said α- or β-hydroxy ketone procedes a step of contacting the hide with a chrome salt or tannin.  
     
     
         9 . The process of  claim 8 , wherein said concentration of α- or β-hydroxy ketone ranges from about 0.5% to about 10% in weight based on the total weight of hide.  
     
     
         10 . The process of  claim 8 , wherein said concentration of α- or β-hydroxy ketone ranges from about 1% to about 5% in weight based on the total weight of hide.  
     
     
         11 . A process of tanning hide, characterized in that it comprises some or all of the following steps: 
 (a) deliming;    (b) bating;    (c) pickling;    (d) conditioning with an α-hydroxy ketone of General Formula (I):                          wherein R 1  is a linear or ramified alkyl group or an aromatic group and R 1  and R 2  independently are hydrogen, a linear or ramified alkyl group or an aromatic group, and R 1  and R 2  are not concomitantly H,    or with a β-hydroxy ketone of General Formula II:                          wherein R is a linear or ramified alkyl group or an aromatic group and R 1  and R 2  and R 3  independently are hydrogen, a linear or ramified alkyl group or an aromatic group; and    (e) chromium or tannin tanning.    
     
     
         12 . A hide tanned by the process of  claim 1.