Acrylated maleic-modified rosin ester and method of preparation

Abstract

A two-step method for introducing acrylic functions into high molecular weight natural resins, under mild conditions, without the risk of gellation, wherein an acrylated natural resin ester is prepared by esterifying one or more of the sterically hindered hydroxy groups of the natural resin ester in an inert solvent with a 3-halopropionic acid, to form a 3-haloproprionate ester of the natural resin ester and dehydrohalogenated the 3-halopropionate ester by reacting it with an organic base.

What is claimed is:  
     
         1 . An acrylated maleic-modified rosin ester comprising: a maleic-modified rosin ester moiety and one or more acrylate moieties connected directly to the maleic-modified rosin ester moiety through an ester linkage; and, optionally, one or more hydroxy moieties; wherein the acrylated maleic-modified rosin ester contains about 30 equivalent % or more of the acrylate moieties based on the total equivalents of the acrylate moieties and the hydroxy moieties and is substantially free of polymerized acrylate moieties.  
     
     
         2 . The acrylated maleic-modified rosin ester of  claim 1  containing about 40 equivalent % to about 75 equivalent % of the acrylate moieties based on the total equivalents of the acrylate moieties and the hydroxy moieties.  
     
     
         3 . An acrylated maleic-modified rosin ester composition made by the process comprising the steps of: 
 A: esterifying one or more sterically hindered hydroxy groups of a natural resin ester, with 3-halopropionic acid at an esterification temperature of about 100° C. or more to form a 3-halopropionate ester of the natural resin ester;    B: reacting the 3-halopropionate ester with an organic base at a second reaction temperature of about 100° C. or less to form the acrylated natural resin ester.    
     
     
         4 . The composition of  claim 3  wherein the natural resin ester is a rosin ester.  
     
     
         5 . The composition of  claim 3  wherein the natural resin ester is a maleated rosin ester.  
     
     
         6 . The composition of  claim 5  wherein the maleated rosin ester is a reaction product of rosin, maleic anhydride, and a polyol.  
     
     
         7 . The method of  claim 6  wherein the polyol is ethylene glycol, propylene glycol, neopentyl glycol, 2-ethyl-2-butyl propanediol, polyethylene glycol, polypropylene glycol, glycerol, trimethylol ethane, trimethylol propane, trimethylol butane, pentaerythritol, dipentaerythitol, sorbitol, or a mixture thereof.  
     
     
         8 . The composition of  claim 3  wherein the 3-halopropionic acid is 3-chloro-propionic acid.  
     
     
         9 . The composition of  claim 3  wherein the organic base is tertiary amine selected from a group consisting of example trimethylamine, triethyl amine, tributylamine, triethanolamine, N,N-dimethylbenzylamine, diazabicycloundecene.  
     
     
         10 . The composition of  claim 3  wherein the organic base is triethylamine.  
     
     
         11 . The composition of  claim 3  wherein the esterification temperature is between about 100° C. to about 180° C.  
     
     
         12 . The composition of  claim 3  wherein the esterification temperature is a boiling temperature of a processing solvent.  
     
     
         13 . The composition of  claim 3  wherein the reaction temperature is between about 25° C. to about 80° C.  
     
     
         14 . The composition of  claim 3  wherein Step A is carried out in the presence of an acid catalyst.  
     
     
         15 . The composition of  claim 3  wherein Step B is carried out in the presence of air.  
     
     
         16 . The composition of  claim 3  wherein Step B is carried out in the presence of hydroquinone monomethyl ether.  
     
     
         17 . The composition of  claim 3  wherein about 30 equivalent % of the sterically hindered hydroxy groups are esterified with the 3-halopropionic acid.  
     
     
         18 . The composition of  claim 3  wherein between about 40 equivalent % and 75 equivalent % of the sterically hindered hydroxy groups are esterified with the 3-halopropionic acid.