Process for producing a polyfluoroalkyl (meth) acrylate

Abstract

A process for producing a polyfluoroalkyl (meth)acrylate, which comprises isolating, from a reaction mixture containing a polyfluoroalkyl (meth)acrylate obtained by reacting a polyfluoroalkyl iodide of the formula C n F 2n+1 (CH 2 ) m I (wherein n is an integer of from 2 to 7, and m is an integer of from 1 to 4) with a metal (meth)acrylate in tert-butanol, said polyfluoroalkyl (meth)acrylate by the following steps (1) to (3): (1) a step of taking out a crude liquid from the reaction mixture by solid-liquid separation; (2) a step of distilling the crude liquid to separate it into compound group A of compounds having a lower boiling point than the polyfluoroalkyl (meth)acrylate and compound group B of the polyfluoroalkyl (meth)acrylate and compounds having a higher boiling point than the polyfluoroalkyl (meth)acrylate; and (3) a step of distilling and purifying the polyfluoroalkyl (meth)acrylate from the compound group B in the presence of a polymerization inhibitor.

1 . A process for producing a polyfluoroalkyl (meth)acrylate, which comprises isolating, from a reaction mixture containing a polyfluoroalkyl (meth)acrylate obtained by reacting a polyfluoroalkyl iodide of the formula C n F 2n+1 (CH 2 ) m I (wherein n is an integer of from 2 to 7, and m is an integer of from 1 to 4) with a metal (meth)acrylate in tert-butanol, said polyfluoroalkyl (meth)acrylate by the following steps (1) to (3): 
 (1) a step of taking out a crude liquid from the reaction mixture by solid-liquid separation;    (2) a step of distilling the crude liquid to separate it into compound group A of compounds having a lower boiling point than the polyfluoroalkyl (meth)acrylate and compound group B of the polyfluoroalkyl (meth)acrylate and compounds having a higher boiling point than the polyfluoroalkyl (meth)acrylate; and    (3) a step of distilling and purifying the polyfluoroalkyl (meth)acrylate from the compound group B in the presence of a polymerization inhibitor.    
     
     
         2 . The process according to  claim 1 , wherein the separation method in the step (1) is a filtration method or a centrifugal separation method.  
     
     
         3 . The process according to  claim 1 , wherein the step (2) is carried out in an atmosphere containing oxygen gas.  
     
     
         4 . The process according to  claim 1 , wherein said reaction and/or the step (2) is carried out in the presence of a polymerization inhibitor.  
     
     
         5 . The process according to  claim 1 , wherein the polymerization inhibitor is hydroquinone, methoquinone, phenothiazine, cresol, tert-butyl catechol, diphenylamine, a p-phenylenediamine or an N-oxyl compound.  
     
     
         6 . The process according to  claim 1 , wherein the metal (meth)acrylate is a lithium salt, a sodium salt or a potassium salt.  
     
     
         7 . The process according to  claim 1 , wherein the temperature in the step (1) is from 20 to 60° C.  
     
     
         8 . The process according to  claim 1 , wherein the pressure in the step (2) is from 6.67×10 3  to 66.7×10 3  Pa (from 50 to 500 mmHg).  
     
     
         9 . The process according to  claim 1 , wherein the pressure in the step (3) is from 0.13×10 3  to 3.33×10 3  Pa (from 1 to 25 mmHg).  
     
     
         10 . The process according to  claim 3 , wherein the content of the oxygen gas in the oxygen-containing gas in the step (2) is from 0.01 to 5%, based on the amount of vapor (by volume calculated as in the standard state) generated in a heating tank.