Benzoate/alkanoate ester compositions

Abstract

Mixtures of esters produced by reacting an aromatic and an aliphatic monocarboxylic acid with a stoichiometric quantity of a diol are effective plasticizers for polyvinyl chloride and other rigid organic polymers. The freezing point of the mixtures and the efficacy of the present ester mixtures as plasticizers can be varied by adjusting the type and molar ratio of the two types of acids used to prepare the ester mixture.

That which is claimed is:  
     
         1 . An ester composition comprising 
 1) an ester corresponding to formula (I)    R 1 C(O)OR 2 O(O)CR 3   I    2) an ester corresponding to formula (II)    R 1 C(O)OR 2 O(O)CR 1 ;  II and    3)an ester corresponding to formula (III)    R 3 C(O)OR 2 O(O)CR 3   III    wherein R 1  is at least one radical selected from the group consisting of phenyl and alkyl-substituted phenyl, R 2  is a divalent radical of the formula —R 4 (OR 4 ) m —, R 3  is an alkyl radical containing from 3 to 21 carbon atoms, R 4  is an alkyl radical containing from 2 to 4 carbon atoms, and m represents 0 or the integer 1 or 2.    
     
     
         2 . A composition according to  claim 1  wherein the molar ratio of R 1 C(O)— to R 3 C(O)— groups in said composition is at least 1:1 and said composition is a liquid at 25° C.  
     
     
         3 . A composition according to  claim 2  wherein said molar ratio is from 1:1 to 12:1.  
     
     
         4 . A composition according to  claim 3  wherein said composition additionally contains at least one ester exhibiting a formula selected from the group consisting of R 1 C(O)OR 2 OH and R 3 C(O)OR 2 OH.  
     
     
         5 . A composition according to  claim 1  wherein R 1  is phenyl, m is 1 or 2 and R 3  contains from 8 to 16 carbon atoms.  
     
     
         6 . A composition according to  claim 5  wherein R 4  is ethyl or propyl and R 3  contains 11 carbon atoms.  
     
     
         7 . A plasticized polymer composition comprising 1) a polymer selected from the group consisting of homopolymers and copolymers of vinyl chloride and 2) a plasticizer comprising 
 1) an ester corresponding to formula (1)    R 1 C(O)OR 2 O(O)CR 3   I    2) an ester corresponding to formula (II)    R 1 C(O)OR 2 O(O)CR 1 ;  II and    3) an ester corresponding to formula (III)    R 3 C(O)OR 2 O(O)CR 3   III    wherein R 1  is at least one radical selected from the group consisting of phenyl and alkyl-substituted phenyl, R 2  is a divalent radical of the formula —R 4 (OR 4 ) m —, R 3  is an alkyl radical containing from 3 to 21 carbon atoms, R 4  is an alkyl radical containing from 2 to 4 carbon atoms, and m represents 0 or the integer 1 or 2.    
     
     
         8 . A polymer composition according to  claim 7  wherein the molar ratio of R 1 C(O)— to R 3 C(O)— groups in said composition is at least 1:1, and said composition is a liquid at 25° C.  
     
     
         9 . A polymer composition according to  claim 8  wherein said molar ratio is from 1:1 to 12:1.  
     
     
         10 . A polymer composition according to  claim 7  wherein R 1  is phenyl and m is 1 or 2 and R 3 . contains from 8 to 16 carbon atoms.  
     
     
         11 . A polymer composition according to  claim 10  wherein R 4  is ethyl or propyl and R3 contains 11 carbon atoms.