Hydrophobic polymer dispersion and process for the preparation thereof

Abstract

The invention relates to a hydrophobic polymer dispersion and a solvent-free process for the preparation thereof. According to the invention, the dispersion contains starch ester together with dispersion admixtures known as such. According to the process, the polymer is first mixed with a plasticizer in order to obtain a plasticized polymer blend. The platicized polymer blend is then mixed with dispersion admixtures and water at an elevated temperature so as to form a dispersion. The plasticizing of the polymer and the dispersion of the mixture in water can be performed in an extruder. The obtained dispersion is homogenized in order to improve its stability. The dispersion obtained by the invention can be used to coat paper or board, as a primer or a component in paint or labelling adhesives, and it is also suitable for the production of cast films and as a binder in materials based on cellulose fibers, as well as for coating medicinal preparations.

1 . A method of coating a substrate which comprises applying to the substrate a coating which comprises polymer dispersion containing a modified starch ester dispersed in a liquid phase wherein the degree of substitution (DS) of the starch ester is greater than 1.5.  
     
     
         2 . The method according to  claim 1 , wherein the substrate is selected from the group consisting of paper, board and medicinal tablets.  
     
     
         3 . A method of manufacturing a primer composition for paint which comprises formulating said primer composition with a polymer dispersion containing a modified starch ester dispersed in a liquid phase wherein the degree of substitution (DS) of the starch ester is greater than 1.5.  
     
     
         4 . A method of manufacturing a labeling adhesive composition which comprises formulating said adhesive composition with a polymer dispersion containing a modified starch ester dispersed in a liquid phase wherein the degree of substitution (DS) of the starch ester is greater than 1.5.  
     
     
         5 . A method of manufacturing a cast film composition which comprises formulating said cast film composition with a polymer dispersion containing a modified starch ester dispersed in a liquid phase wherein the degree of substitution (DS) of the starch ester is greater than 1.5.  
     
     
         6 . A method of manufacturing a binding agent composition for materials containing cellulose fibers which comprises formulating said cast film composition with a polymer dispersion containing a modified starch ester dispersed in a liquid phase wherein the degree of substitution (DS) of the starch ester is greater than 1.5.