Viscoelastic Polyurethane Foam with Aqueous Polymer Dispersion

Abstract

A reaction system for forming a viscoelastic polyurethane foam includes an isocyanate component that has at least one isocyanate and an isocyanate-reactive component that is a mixture formed by adding at least a polyol component, an additive component, and a preformed aqueous polymer dispersion. The mixture includes, based on the total weight of the mixture, from 50.0 wt % to 99.8 wt % of a polyol component including at least one polyether polyol, from 0.1 wt % to 50.0 wt % of an additive component including at least one catalyst, and from 0.1 wt % to 6.0 wt % of a preformed aqueous polymer dispersion. The preformed aqueous polymer dispersion has a solids content from 10 wt % to 80 wt %, based on the total weight of the preformed aqueous polymer dispersion, and is one of an aqueous acid polymer dispersion or an aqueous acid modified polyolefin polymer dispersion in which the polyolefin is derived from at least one C 2 to C 20 alpha-olefin.

1 - 12 . (canceled) 
     
     
         13 . A method for forming a viscoelastic polyurethane foam that has a resiliency of less than 20% as measured according to ASTM D 3574, the method comprising:
 providing a preformed aqueous dispersion that has a solids content from 10 wt % to 80 wt % based on the total weight of the preformed aqueous polymer dispersion, the preformed aqueous dispersion being one of an aqueous acid polymer dispersion or an aqueous acid modified polyolefin polymer dispersion in which the polyolefin is derived from at least one C 2  to C 20  alpha-olefin;   preparing an isocyanate-reactive component by mixing at least a polyol component, an additive component, and the preformed aqueous dispersion, the resultant mixture including:
 from 50.0 wt % to 99.8 wt % of a polyol component, based on the total weight of the mixture, the polyol component including at least one polyether polyol, 
 from 0.1 wt % to 50.0 wt % of an additive component, based on the total weight of the mixture, that includes at least one catalyst and at least one surfactant, and 
 from 0.1 wt % to 6.0 wt % of the preformed aqueous polymer dispersion, based on the total weight of the mixture; 
   providing an isocyanate component that includes at least one isocyanate such that an isocyanate index of the reaction system is from 50 to 110; and   allowing the isocyanate component to react with the isocyanate-reactive component to form the viscoelastic polyurethane foam.   
     
     
         14 . The method as claimed in  claim 13 , wherein the preformed aqueous polymer dispersion is a continuous liquid phase component at ambient conditions of room temperature and atmospheric pressure and is derived from a liquid phase and a solid phase, the liquid phase being water and the solid phase being an acid or an acid-modified polyolefin in which the polyolefin is derived from at least one C 2  to C 20  alpha-olefin. 
     
     
         15 . The method as claimed in  claim 13 , wherein the preformed aqueous polymer dispersion is a continuous liquid phase component at ambient conditions of room temperature and atmospheric pressure and is derived from a liquid phase and a solid phase, the liquid phase being water and the solid phase including an ethylene-acrylic acid copolymer. 
     
     
         16 . The method as claimed in  claim 13 , wherein the preformed aqueous polymer dispersion includes at least one ethylene-acrylic acid copolymer that has an acrylic acid content from 10 wt % to 70 wt %, based on the total weight of the ethylene-acrylic acid copolymer. 
     
     
         17 . The method as claimed in  claim 13 , wherein the additive component includes at least one surfactant. 
     
     
         18 . The method as claimed in  claim 13 , wherein the additive component includes water that accounts for less than 2.0 wt % of the total weight of mixture. 
     
     
         19 . The method as claimed in  claim 13 , wherein the polyol component includes at least one polyoxyethylene-polyoxypropylene polyether polyol that has an ethylene oxide content of at least 50 wt %, has a nominal hydroxyl functionality from 2 to 4, and accounts for 35 wt % to 90 wt % of the isocyanate-reactive component. 
     
     
         20 . The method as claimed in  claim 13 , wherein the polyol component includes a blend of at least three polyols, the blend including:
 (i) a polyoxyethylene-polyoxypropylene polyether polyol that has an ethylene oxide content of at least 50 wt %, has a nominal hydroxyl functionality from 2 to 4, has a number average molecular weight from 700 g/mol to 1500 g/mol, and accounts for 35 wt % to 90 wt % of the isocyanate-reactive component,   (ii) a polyoxypropylene-polyoxyethylene polyether polyol that has an ethylene oxide content of less than 20 wt %, has a nominal hydroxyl functionality from 2 to 4, has a number average molecular weight greater than 1500 g/mol and less than 6000 g/mol, and accounts for 5 wt % to 50 wt % of the isocyanate-reactive component, and   (iii) a polyoxypropylene polyether polyol that has a nominal hydroxyl functionality from 2 to 4, has a number average molecular weight from 700 g/mol to 1500 g/mol, and accounts for 5 wt % to 50 wt % of the isocyanate-reactive component.