Esterification process of polyols with tertiary alkyl substituted acids
View Patent ↗A process to prepare polyol esters from tertiary alkyl acid with reduced homo-polymerisation of the polyols. The ester polyol can be used in the synthesis of further polyester resins for coating or structural/composite or lube oil applications.
1. A process of preparing polyol esters from tertiary alkyl acids comprising reacting a polyol and the tertiary alkyl acid in the presence of an acid catalyst having a pKa from −2 to +2 at a temperature below 180° C., and optionally in presence of an inert organic solvent, wherein the polyol ester is predominantly a mono-ester of the polyol, wherein the acid catalyst is selected from the group consisting of methane sulphonic acid, ethane sulphonic acid, trifluoromethane sulphonic acid, para toluene sulphonic acid, xylene sulphonic acids and combinations thereof.
2. The process of claim 1 , wherein the acid catalyst is methane sulphonic acid or para toluene sulphonic acid.
3. The process of claim 1 , wherein the acid catalyst is used in a range from 0.05 to 4 weight % relative to the weight of the tertiary alkyl acid and the polyol ester.
4. The process claim 1 , wherein the tertiary alkyl acid is represented by the formula (I),
in which R 1 , R 2 are independently aliphatic alkyl radicals of having 1 to 10 carbon atoms, and the total carbon atoms of the three radicals, CH 3 +R 1 +R 2 ranges from 3 to 20.
5. The process claim 1 , wherein the polyol is selected from the group consisting of ethylene glycol, propylene glycol, glycol oligomers having 2 to 10 repeating units, glycerol, neopentyl glycol, trimethylolpropane, pentaerythritol, and combinations thereof.
6. The process of claim 1 , wherein the acid catalyst is used in a range from 0.10 to 2.5 weight % relative to the weight of the tertiary alkyl acid and the polyol ester.
7. The process of claim 1 , wherein the tertiary alkyl acid is represented by formula (I),
in which R 1 , R 2 are independently aliphatic alkyl radicals having 1 to 10 carbon atoms and the total carbon atoms of the three radicals, CH 3 +R 1 +R 2 , ranges from 3 to 13.
8. The process of claim 1 , wherein the polyol is selected from the group consisting of neopentyl glycol, trimethylolpropane, pentaerythritol, and combinations thereof.