Aqueous polyurethane dispersion

Abstract

Provided is an aqueous composition comprising dispersed particles that comprise a polyurethane, wherein said polyurethane is a reaction product of a group of reactants (GR1), wherein GR1 comprises one or more aromatic polyisocyanates and, a polyol component, wherein said polyol component comprises (a) 50% to 99% by weight, based on the weight of said polyol component, one or more polyester polyols, (b) 0.1% to 10% by weight, based on the weight of said polyol component, one or more diols having a hydrophilic side chain, and (c) 0.9% to 40% by weight, based on the weight of said polyol component, one or more polyols different from (a) and (b). Also provided is a method of bonding a metal foil to a polymer film using such an aqueous composition.

1 . An aqueous composition comprising one or more anionic surfactants and further comprising dispersed particles that comprise a polyurethane, wherein said polyurethane is a reaction product of a group of reactants (GR1), wherein GR1 comprises one or more aromatic polyisocyanates and a polyol component, wherein said polyol component comprises
 (a) 50% to 99% by weight, based on the weight of said polyol component, one or more polyester polyols,   (b) 0.1% to 10% by weight, based on the weight of said polyol component, one or more diols having a hydrophilic side chain, and   (c) 0.9% to 40% by weight, based on the weight of said polyol component, one or more polyols different from (a) and (b).   
     
     
         2 . The composition of  claim 1 , wherein (c) comprises 2% to 20% by weight, based on the weight of said polyol component, one or more polyethylene glycols. 
     
     
         3 . The composition of  claim 2 , wherein the total amount in said polyol component of polyether polyols that are not said polyethylene glycols and that are not said diols having a hydrophilic side chain is, by weight based on the total weight of said polyol component, 20% or less. 
     
     
         4 . The composition of  claim 1 , wherein (c) comprises 0.5% to 5% by weight, based on the weight of said polyol component, one or more monomeric diols. 
     
     
         5 . The composition of  claim 1 , wherein said polyester polyol (a) comprises one or more aliphatic polyester polyols. 
     
     
         6 . The composition of  claim 1 , wherein said GR1 additionally comprises one or more polyamines. 
     
     
         7 . The composition of  claim 1 , wherein said composition additionally comprises one or more isocyanate crosslinker. 
     
     
         8 . The composition of  claim 7 , wherein said isocyanate crosslinker comprises one or more hydrophilically modified trimers of monomeric diisocyanates. 
     
     
         9 . An aqueous composition comprising dispersed particles that comprise a polyurethane, wherein said polyurethane is a reaction product of a group of reactants (GR1), wherein GR1 comprises one or more aromatic polyisocyanates and, a polyol component, wherein said polyol component comprises
 (a) 50% to 99% by weight, based on the weight of said polyol component, one or more polyester polyols,   (b) 0.1% to 10% by weight, based on the weight of said polyol component, one or more diols having a hydrophilic side chain, wherein said hydrophilic side chain comprises one or more anionic group; and   (c) 0.9% to 40% by weight, based on the weight of said polyol component, one or more polyols different from (a) and (b).   
     
     
         10 . A method of bonding a metal foil to a polymeric film comprising the steps of
 (A) applying a layer of the composition of  claim 1  to a surface of said metal foil,   (B) drying said layer of said adhesive composition to produce a layer of dried adhesive, and   (C) after said drying, bringing a surface of a polymeric film into contact with said layer of said dried adhesive composition.