Sorbitan esters and process for enzymatically preparing same

Abstract

A process can be used for enzymatic preparation of sorbitan carboxylates. Sorbitan carboxylates are obtainable by this process.

1 . A process for enzymatic preparation of a sorbitol carboxylate, comprising:
 A) blending sorbitol and at least one acyl group donor, within a temperature range of 80° C. to 120° C., for at least 10 minutes.   B) reacting the sorbitol with the at least one acyl group donor in the presence of a lipase at a temperature of 75° C. to 110° C., to give a sorbitol carboxylate, and   C) optionally, purifying the sorbitol carboxylate.   
     
     
         2 . The process according to  claim 1 , wherein the at least one acyl group donor provided in A) provides acyl groups that derive from a carboxylic acid containing 2 to 34 carbon atoms or a mixture thereof. 
     
     
         3 . The process according to  claim 1 , wherein the sorbitol and the at least one acyl group donor make up at least 80% by weight, based on an overall reaction mixture at the start of B). 
     
     
         4 . The process according to  claim 1 , wherein in B), a water content based on an overall reaction mixture is less than 15% by weight. 
     
     
         5 . The process according to  claim 1 , wherein the lipase is selected from the group consisting of a lipase from  Thermomyces lanuginosus , a lipase A or B from  Candida antarctica , a lipase from  Mucor miehei , a lipase from  Humicola  sp., a lipase from  Rhizomucor javanicus , a lipase from  Rhizopus oryzae , a lipase from  Candida rugosa , a lipase from  Rhizopus niveus , a lipase from  Penicillium camemberti , a lipase from  Aspergillus niger , a lipase from  Penicillium cyclopium , and a respective at least 60% homologue thereof at an amino acid level. 
     
     
         6 . The process according to  claim 1 , wherein B) is conducted at a pressure of less than 1 bar. 
     
     
         7 . The process according to  claim 1 , wherein B) is ended no later than 180 hours after the lipase has been added. 
     
     
         8 . The process according to  claim 1 , wherein a molar ratio of the sorbitol provided to all acyl groups present in the at least one acyl group donor provided is within a range from 1.00:0.50 to 1.00:5.00. 
     
     
         9 . A sorbitol carboxylate obtainable by the process according to  claim 1 . 
     
     
         10 . The sorbitol carboxylate according to  claim 9 , containing:
 at least one carboxylic ester of sorbitol, and   at least one of a carboxylic ester of 1,4-anhydrosorbitol, a carboxylic ester of 2,5-anhydrosorbitol, a carboxylic ester of 1,5-anhydrosorbitol, and a carboxylic ester of isosorbide,   where a ratio by weight of sorbitol residues present in the sorbitol carboxylate to a sum total of all 1,4-anhydrosorbitol residues, 2,5-anhydrosorbitol residues, 1,5-anhydrosorbitol residues, and isosorbide residues present in the sorbitol carboxylate is greater than 90:10,   wherein a molar ratio of esterified primary hydroxyl groups to esterified secondary hydroxyl groups in the at least one carboxylic ester of sorbitol is 80:20 to 20:80.   
     
     
         11 . The sorbitol carboxylate according to  claim 9 , wherein an average degree of esterification of the at least one carboxylic ester of sorbitol present is from 0.3 to 4.0. 
     
     
         12 . The sorbitol carboxylate according to  claim 9 , wherein the sorbitol carboxylate contains 0.05% to 40% by weigh of free sorbitol. 
     
     
         13 . The sorbitol carboxylate according to  claim 9 , wherein the sorbitol carboxylate contains less than 25% by weight of at least one free carboxylic acid. 
     
     
         14 . The sorbitol carboxylate according to  claim 9 , wherein a total monoester content of the at least one carboxylic ester of sorbitol contains from 5% by weight to 25% by weight of secondary ester regioisomers. 
     
     
         15 . The sorbitol carboxylate according to  claim 9 , wherein the sorbitol carboxylate is a viscosity regulator, a care active ingredient, a foam booster or solubilizer, an antimicrobial, an antistat, a binder, a corrosion inhibitor, a dispersant, an emulsifier, a film former, a humectant, an opacifier, an oral care agent, a preservative, a skincare agent, a hydrophilic emollient, a foam stabilizer, or a nonionic surfactant. 
     
     
         16 . The process according to  claim 1 , wherein the at least one acyl group donor is selected from the group consisting of a fatty acid ester and a fatty acid. 
     
     
         17 . The process according to  claim 1 , wherein in B), the reacting is at a temperature of 80° C. to 95° C. 
     
     
         18 . The process according to  claim 1 , wherein in A), the blending is at a temperature range of 100° C. to 120° C., for at least 60 minutes. 
     
     
         19 . The process according to  claim 2 , wherein the at least one acyl group donor is a natural fatty acid or a mixture thereof. 
     
     
         20 . The process according to  claim 3 , wherein the sorbitol and the at least one acyl group donor make up at least 95% by weight, based on the overall reaction mixture at the start of B).