Process for manufacturing reduced water content (meth)acrylic acid

Abstract

A method is provided herein for purifying (meth)acrylic acid to provide a purified (meth)acrylic acid product having a low aldehyde concentration and not more than 0.2 wt % water. One embodiment of the method includes distilling (meth)acrylic acid in the presence of an aldehyde treating compound. Another embodiment of the method includes also distilling crude (meth)acrylic acid in the presence of a reactive drying agent. (Meth)acrylic acid produced in this manner is especially suitable for use in specialty (meth)acrylic acid polymers, such as for example superabsorbent polymers, binders, and ethylene-(M)AA copolymers.

1 - 14 . (canceled) 
     
     
         15 . A (meth)acrylic acid product comprising less than 1% impurities and less than 5 ppm furfural. 
     
     
         16 . The (meth)acrylic acid product of  claim 15 , further comprising not more than 0.2 wt % water based on the total weight of the (meth)acrylic acid product. 
     
     
         17 . The (meth)acrylic acid product of  claim 16 , further comprising not more than 5 ppm acrolein, not more than 5 ppm benzaldehyde, and not more than 5 ppm protoanemonin. 
     
     
         18 . A specialty polymer composition comprising units derived from at least the (meth)acrylic acid product of  claim 15 . 
     
     
         19 . (canceled) 
     
     
         20 . A method of purifying a (meth)acrylic acid stream using a distillation apparatus, comprising maintaining the temperature at the bottom of the distillation apparatus at not more than 110° C. 
     
     
         21 . The method of  claim 20 , wherein the production of methyl vinyl ketone within the distillation apparatus is minimized. 
     
     
         22 . The method of  claim 21 , further comprising producing a final product (meth)acrylic acid stream comprising no more than 25 ppm methyl vinyl ketone.