Continuous processes and apparatus for forming cyanoacetate and cyanoacrylate

Abstract

Continuous processes for forming cyanoacrylate from polycyanoacrylate include stripping a solvent from a reaction mass; cracking a polymer in the reaction mass to form a cracked cyanoacrylate monomer and residue substances; and distilling the cracked cyanoacrylate monomer to produce a cyanoacrylate monomer product. These steps can be performed in short-path, wiped-film evaporators. Polycyanoacrylate used in the processes can be formed using cyanoacetate produced by processes for continuously producing cyanoacetate by forming a higher homologue cyanoacetate from a lower homologue cyanoacetate. The cyanoacetate can be formed in short-path, wiped-film evaporators.

1 . A process for continuously producing cyanoacrylate monomer, comprising the steps: 
 (a) stripping solvent from a reaction mass comprising polycyanoacrylate and solvent to produce stripped polycyanoacrylate;    (b) cracking the stripped polycyanoacrylate to form a cracked cyanoacrylate monomer and residue substances in a short-path, wiped-film evaporator; and    (c) distilling the cracked cyanoacrylate monomer to produce a purified cyanoacrylate monomer.    
     
     
         2 . A process for continuously making cyanoacetate, comprising: 
 converting a first cyanoacetate to a second cyanoacetate via a transesterification reaction in a first wiped-film evaporator; and    purifying the second cyanoacetate in a second wiped-film evaporator;    wherein the first cyanoacetate is a lower homologue cyanoacetate and the second cyanoacetate is a higher homologue cyanoacetate as compared to each other.    
     
     
         3 . The process of  claim 2 , wherein the first cyanoacetate is ethyl cyanoacetate or methyl cyanoacetate, and the second cyanoacetate is 2-octyl cyanoacetate.  
     
     
         4 . The process of  claim 2 , wherein the first wiped-film evaporator and the second wiped-film evaporator are the same wiped-film evaporator.  
     
     
         5 . The process of  claim 2 , wherein the first wiped-film evaporator and the second wiped-film evaporator are each a short-path wiped-film evaporator.  
     
     
         6 . The process of  claim 2 , wherein the first wiped-film evaporator operates at a temperature of from about 100° C. to about 250° C. and at about atmospheric pressure during the converting step.  
     
     
         7 . The process of  claim 2 , wherein the second wiped-film evaporator operates at a temperature of from about 75° C. to about 105° C. and a pressure of about 0.5 torr to about 10 torr during the purifying step.  
     
     
         8 . An apparatus for continuously producing cyanoacrylate monomer, comprising: 
 (a) means for stripping solvent from a reaction mass comprising polycyanoacrylate and solvent to produce stripped polycyanoacrylate;    (b) means for cracking the stripped polycyanoacrylate to form a cracked cyanoacrylate monomer and residue substances; and    (c) means for distilling the cracked cyanoacrylate monomer to produce a purified cyanoacrylate monomer.    
     
     
         9 . An apparatus for continuously producing cyanoacrylate monomer, comprising: 
 (a) a first wiped-film evaporator for stripping solvent from a reaction mass comprising polycyanoacrylate and solvent to produce stripped polycyanoacrylate;    (b) a separate second wiped-film evaporator for cracking the stripped polycyanoacrylate to form a cracked cyanoacrylate monomer and residue substances; and    (c) at least one separate evaporator for distilling the cracked cyanoacrylate monomer to produce a purified cyanoacrylate monomer.    
     
     
         10 . The apparatus of  claim 9 , wherein the evaporator further comprises a third wiped-film evaporator for distilling the cracked cyanoacrylate monomer and the volatile substances to separate the residue substances from the cracked cyanoacrylate monomer.  
     
     
         11 . The apparatus of  claim 10 , wherein the evaporator further comprises a fourth wiped-film evaporator for distilling the distilled cracked cyanoacrylate monomer to produce a purified cyanoacrylate monomer.  
     
     
         12 . The apparatus of  claim 11 , wherein the third and fourth wiped-film evaporators are short-path, wiped-film evaporators.  
     
     
         13 . The apparatus of  claim 9 , wherein the second wiped-film evaporator is a short-path, wiped film evaporator.  
     
     
         14 . The apparatus of  claim 9 , wherein the first wiped-film evaporator and the second wiped-film evaporator are each a short-path, wiped-film evaporator.  
     
     
         15 . The apparatus of  claim 9 , further comprising an apparatus for continuously forming cyanoacetate.  
     
     
         16 . The apparatus of  claim 15 , wherein the apparatus for continuously forming cyanoacetate comprises: 
 a fifth wiped-film evaporator for synthesizing a second cyanoacetate via a reaction of a first cyanoacetate; and    a sixth wiped-film evaporator for purifying the second cyanoacetate.    
     
     
         17 . The apparatus of  claim 16 , wherein the fifth wiped-film evaporator and the sixth wiped-film evaporator are each a short-path, wiped-film evaporator.  
     
     
         18 . An apparatus for continuously producing cyanoacrylate monomer, comprising: 
 (a) means for stripping solvent from a reaction mass comprising polycyanoacrylate and solvent in a first wiped-film evaporator to produce stripped polycyanoacrylate;    (b) means for cracking the stripped polycyanoacrylate to form a cracked cyanoacrylate monomer and residue substances in a second wiped-film evaporator; and    (c) means for distilling the cracked cyanoacrylate monomer to produce a purified cyanoacrylate monomer.