Aqueous dispersions of low-molecular weight, low-melting and water insoluble polymers

Abstract

An aqueous dispersion of (a) 0.1-40% by wt. of a low molecular weight, low melting point, water-insoluble polymer in which the polymer particles have a size <10 microns, and (b) 0.001-30% by wt. of an anionic emulsifier.

What is claimed is:  
     
         1 . An aqueous dispersion of (a) 0.1-40% by wt. of a low molecular weight, low melting point, water-insoluble polymer in which the polymer particles have a size <10 microns, and (b) 0.001-30% by wt. of an anionic emulsifier.  
     
     
         2 . An aqueous dispersion according to  claim 1  wherein (a) is 5-30% and (b) is 0.002-20%.  
     
     
         3 . An aqueous dispersion according to  claim 1  wherein (a) is 10-20% and (b) is 0.005-10%.  
     
     
         4 . An aqueous dispersion according to  claim 1  wherein (a) is a vinyl pyrrolidone copolymer.  
     
     
         5 . An aqueous dispersion according to  claim 4  wherein (a) is a vinyl pyrrolidone-alkylated or vinyl acetate copolymer.  
     
     
         6 . An aqueous dispersion according to  claim 1  wherein (b) is sodium lauryl sulfate, calcium dodecyl benzene sulfonate, tristyryl ethoxylated phosphoric acid, or salts thereof, polymeric anionic emulsifiers including lignin sulfonate, neutralized methyl vinyl ether maleic acid half-ester, and polyacrylic acid with >10% acrylic acid, or salts thereof, and mixtures of the above.  
     
     
         7 . An aqueous dispersion according to  claim 1  wherein (a) has a molecular weight <100,000 and a pyrrolidone content >10%.  
     
     
         8 . A process of making the aqueous dispersion of  claim 1  which comprises heating said polymer and anionic emulsifier in water at a temperature close to the Tg of the polymer under high shear mixing conditions.  
     
     
         9 . A process according to  claim 8  wherein said temperature is 40-90° C.  
     
     
         10 . A process according to  claim 9  wherein said temperature is 50-80° C.  
     
     
         11 . A process according to  claim 9  wherein said temperature is 60-75° C.  
     
     
         12 . A process according to  claim 8  wherein said polymer and anionic emulsifier is present in amounts of 1-40 wt. % and 0.001-30 wt. %, respectively.  
     
     
         13 . A water-resistant composition including the aqueous dispersion of  claim 1 .  
     
     
         14 . A water-resistant composition according to  claim 13  which includes said dispersion at a dilution of 1:10 to 1:1000.