Polyol Ester Plasticizers and Process of Making the Same

Abstract

Triglyceride and other polyol ester PVC plasticizers can be produced by recovery of branched C6 to C9 aldehydes from a hydroformylation product, optional hydrogenation to the alcohol, oxidation to the acid with oxygen and/or air, recovery of the resulting acid, and esterification with glycerol, ethylene glycol, propylene glycol or mixtures thereof. The branched alkyl chains comprise at least 10% methyl branching. Special triglycerides are derived from branched aliphatic acids having alkyl chains with average carbon numbers from 6 to 9 and at least 10% methyl branching. These triglycerides are fast fusing plasticisers if before esterification with glycerol, an aryl acid is introduced together with the aliphatic acids.

1 . A process for the production of a polyol ester comprising:
 (i) preparing at least one branched C6 to C9 aldehyde using a hydroformylation step, wherein the branched C6 to C9 aldehyde has an average branching of from 0.5 to 3.0 branches per molecule and at least 10% of the branches are methyl branches;   (ii) preparing a branched C6 to C9 acid by oxidizing the branched C6 to C9 aldehyde to the acid, or by first hydrogenating the branched C6 to C9 aldehyde to a branched C6 to C9 alcohol and subsequently oxidizing the branched C6 to C9 alcohol to the acid;   (iii) esterifying the branched C6 to C9 acid with a polyol selected from glycerol, ethylene glycol, and propylene glycol, and mixtures thereof.   
     
     
         2 . The process according to  claim 1  wherein the oxidation in step (ii) comprises the use of oxygen and/or air. 
     
     
         3 . The process according to  claim 1  wherein the oxidation in step (ii) of the branched C6 to C9 alcohol to the acid is performed in the presence of a heterogeneous catalyst, preferably a Pt on carbon catalyst. 
     
     
         4 . The process according to  claim 1 , wherein the hydroformylation in step (i) prepares at least one C3 to C6 aldehyde, and wherein the branched C6 to C9 aldehyde is obtained by aldolisation of the C3 to C6 aldehyde, or mixtures thereof, preferably wherein the branched C6 to C9 aldehyde is obtained by the aldolisation of a mixture of propionaldehyde and a butyraldehyde. 
     
     
         5 . The process according to  claim 4  wherein one or more C5 aldehydes are produced and a part thereof is aldolised to form a C10 aldehyde, whereby the C5 and/or the C10 aldehyde is converted to the respective C5 and/or C10 acid or acid mixture and the acid or acid mixture is used, individually or in combination, in a mixture of acids containing branched acids and having an average carbon number of at least 6 and at most 9, as the feedstock for the polyol ester. 
     
     
         6 . The process according to  claim 1 , further comprising providing as part of step (i) a higher olefin feed for the hydroformylation step by the oligomerization of a lower olefin feedstock. 
     
     
         7 . The process according to  claim 6 , wherein said lower olefin feedstock comprises an olefin selected from propylene, butenes, and mixtures thereof. 
     
     
         8 . The process according to  claim 1 , wherein the branched C6 to C9 acid is esterified in step (iii) in combination with an aromatic acid selected from the group consisting of benzoic acid, 2-methyl benzoic acid, 3-methyl benzoic acid, 4-methyl benzoic acid, 4-tert-butyl benzoic acid and mixtures thereof. 
     
     
         9 . A composition comprising a triglyceride according to the formula 
       
         
           
           
               
               
           
         
       
       wherein at least one of the R1, R2, and R3 groups defining the acid moieties in the triglyceride, is independently selected from C4 to C9 alkyl groups, whereby, if at least one of a C4 or a C9 alkyl group is present, this C4 or C9 group is present in a mixture of aliphatic acids, and whereby the mixture of aliphatic acids has an average carbon number of at least 6 and at most 9, with the proviso that the average branching on the alkyl groups of the aliphatic acid moieties is from 0.5 to 3.0, preferably from 0.6 to 2.2, more preferably from 0.7 to 1.8, still more preferably 0.8 to 1.6, and yet still more preferably from 1.2 to 1.4 branches per molecule, and wherein at least 10% of the branches, preferably at least 50% of the branches, and more preferably at least 80% of the branches on the alkyl groups of the aliphatic acid moieties are methyl branches. 
     
     
         10 . A composition comprising PVC and the composition according to  claim 9 . 
     
     
         11 . The composition according to  claim 9 , wherein each of R1, R2, and R3 is a C6 alkyl group, and wherein the average branching is about 1.2±0.1 per molecule, and wherein the branches are selected from methyl and a combination of methyl and ethyl branches. 
     
     
         12 . The composition according to  claim 9 , wherein at least one of the acid moieties has an average carbon number from 6.5 to 7.5 and has, as determined by C13-NMR, from 5 to 20% of its first branch, counting from the oxygen in the acid or ester function, on the second carbon, from 15 to 40% of the first branch on the third carbon, and from 20 to 40% of the first branch on the 4 th  carbon. 
     
     
         13 . The composition according to  claim 9  wherein at least one of the acid moieties comprising R1, R2, or R3 is selected from the group consisting of benzoic acid, 2-methyl benzoic acid, 3-methyl benzoic acid, 4-methyl benzoic acid, 4-tert-butyl benzoic acid and mixtures thereof. 
     
     
         14 . The composition according to  claim 13  further comprising a phthalate plasticiser, preferably selected from the group consisting of di-isononyl phthalate, di-isodecyl phthalate, di-2-propylheptyl phthalate, di-isoundecyl phthalate, di-2-ethylhexyl phthalate, and mixtures thereof. 
     
     
         15 . (canceled)