Patent ID: 9388118
Filing Date: 2016-07-12
CPC Classification: C07C

Claim Text:
1. A continuous process for preparing (meth)acrylates of C 10 -alcohol mixtures, the process comprising: (A) esterifying, in a reaction zone, glacial (meth)acrylic acid with an isomer mixture of propytheptanol isomers in the presence of a acidic catalyst, at least one polymerization inhibitor and an azeotroping agent for the water of esterification, such that the water of esterification is drawn off in a distillation zone connected atop the reaction zone as an azeotrope with the azeotroping agent, to obtain a reaction output; (B) neutralizing the acidic catalyst and unconverted glacial (meth)acrylic acid in the reaction output with an alkaline solution to obtain a crude propylheptyl (meth)acrylate; (C) washing the crude propylheptyl (meth)acrylate to remove residues of salts from the crude propylheptyl (meth)acrylate, to obtain a washed crude propylheptyl (meth)acrylate; (D) distilling the washed crude propytheptyl (meth)acrylate under reduced pressure and with continuous metered addition of at least one polymerization inhibitor, while drawing off the azeotroping agent, other low boilers and a very small proportion of propylheptyl (meth)acrylate; (E) removing low boilers from a bottom stream of the distillation (D) under reduced pressure and with continuous metered addition of at least one polymerization inhibitor to remove residues of low boilers and a small proportion of the propylheptyl (meth)acrylate; (F) air saturating the bottom stream in countercurrent by blowing in an oxygenous gas mixture and removing a resulting offgas, to form a resulting bottom stream; (G) distilling the resulting bottom stream under reduced pressure and with continuous metered addition of at least one polymerization inhibitor to obtain glacial propylheptyl (meth)acrylate and a further bottom stream comprising polymerization inhibitors and high boilers; (H) distilling the further bottom stream under reduced pressure and with continuous metered addition of at least one polymerization inhibitor, with separation of residual propylheptyl (meth)acrylate from polymerization inhibitors and high boilers, to obtain (meth)acrylates of C wherein the isomer mixture of propylheptanol isomers comprises 2-propylheptanol as the main isomer and at least one of the 2-propyl-4-methythexanol, 2-propyl-5-methylhexanol, 2-isopropylheptanol, 2-isopropyl-4-methylhexanot, 2-isopropyi-5-methylhexanol and 2-propyl-4,4-dimethylpentanot.