Method for producing 2-dimethylaminoethyl (meth)acrylate
AssigneeSnf Group
InventorsCédrick Favero, Johann Kieffer, Jing Ling
Life of this patent
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Abstract
Process for the production of 2-dimethylaminoethyl (meth)acrylate in multiple stage batch reactions involving the recycling of the catalyst (DBTO) in subsequent reaction, the addition a certain amount of fresh catalyst to the recycled catalyst, the use of said catalysts in the subsequent reaction, and wherein the volume decrease due to azeotropic distillation is compensate in order to keep the volume constant in the reactor during the reaction by the continuous addition of a composition comprising methyl(meth)acrylate and dimethylaminoethanol.
Claims18
A process for the production of 2-dimethylaminoethyl (meth)acrylate comprising a total of at least two and up to twenty sequential batch reactions wherein in each batch reaction, methyl(meth)acrylate, dimethylaminoethanol, dibutyltin oxide as catalyst, and a solvent are added as initial charge in an agitated reactor equipped with a distillation column, wherein an azeotropic distillation is made continuously during the reaction, wherein the volume decrease due to said azeotropic distillation is compensated in order to keep the volume constant in the reactor during the reaction by the continuous addition of a composition comprising methyl(meth)acrylate and dimethylaminoethanol, said composition may also comprise dibutyltin oxide said process comprising:
- a first batch reaction wherein the dibutyltin oxide used as catalyst is a fresh dibutyltin oxide;
- a separation step wherein the dibutyltin oxide from the first batch reaction is recovered from the reaction mixture of the first batch reaction, and that constitutes a recycled dibutyltin oxide;
- at least a second batch reaction wherein at least 65% by weight of the recycled dibutyltin oxide is used with fresh dibutyltin oxide as catalyst of the second batch reaction:
- wherein the amount of fresh dibutyltin oxide is comprised between 0.1% by weight and 35% by weight based on the recycled dibutyltin oxide from the first batch reaction,
- wherein the mass proportion of recycled dibutyltin oxide and fresh dibutyltin oxide, added in the initial charge is comprised between 220/1 and 80/20, and
- wherein the mass proportion of recycled dibutyltin oxide and fresh dibutyltin oxide is between 100/0 and 0/100, in the composition continuously added to compensate the azeotropic distillation, when said composition comprises dibutyltin oxide;
- wherein in each batch reaction, the recycled dibutyltin oxide from the previous reaction is used in combination with fresh dibutyltin oxide as catalyst, and
- wherein the solvent is an alkane from C6 to C12, linear, cyclic or branched.
Dependencies are inferred from the claim text.