Two-component solventless adhesive compositions comprising an amine-initiated polyol

Abstract

A two-component solventless adhesive composition is disclosed, the adhesive composition comprising an isocyanate component comprising at least one isocyanate, and a polyol component comprising at least one amine-initiated polyol having a functionality of from 3 to 8 and a hydroxyl number of from 20 to 1,000. Further, a method for forming a laminate is disclosed, the method comprising forming a solventless adhesive composition comprising an amine-initiated polyol, applying a layer of the adhesive composition to a surface of a film, bringing the layer into contact with a surface of another film to form a laminate, and curing the adhesive composition. Still further, a laminate formed by the method is disclosed.

1 . A premixed two-component solventless adhesive composition, comprising:
 an isocyanate component comprising at least one isocyanate; and   a polyol component comprising at least one amine-initiated polyol having a functionality of from 3 to 8 and a hydroxyl number of from 20 to 1,000.   
     
     
         2 . The two-component solventless adhesive composition of  claim 1 , wherein the at least one isocyanate is selected from the group consisting of a monomeric isocyanate, a polymeric isocyanate, an isocyanate prepolymer, and combinations of two or more thereof. 
     
     
         3 . The two-component solventless adhesive composition of  claim 1 , wherein the at least one isocyanate is selected from the group consisting of hexamethylene diisocyanate (“HDI”) and isomers thereof, isophorone diisocyanate (“IPDI”) and isomers thereof, norbornane diisocyanate (“NBDI”) and isomers thereof, tetramethylxylylene diisocyanate (“TMXDI”) and isomers thereof, xylylene diisocyanate (“XDI”) and isomers thereof, toluene diisocyanate (“TDI”) and isomers thereof, diphenylmethane diisocyanate (“MDI”) and isomers thereof, isocyanate prepolymers thereof, and combinations of two or more thereof. 
     
     
         4 . The two-component solventless adhesive composition of  claim 1 , wherein the amine-initiated polyol is the reaction product of a C 1 -C 6  alkylene oxide and an amine 
     
     
         5 . The two-component solventless adhesive composition of  claim 4 , wherein the amine is selected from the group consisting of toluene diamine, methylamine, ethylenediamine, diethylenetriamine, aniline, aminoethylethanolamine, bis-3-aminopropylmethylamine, propylenediamine, tetra-or hexamethyleneamine, triethanolamine, phenylenediamine, and combinations of two or more thereof. 
     
     
         6 . The two-component solventless adhesive composition of  claim 1 , wherein the amine-initiated polyol accounts for 0.5 to 12 wt % of the adhesive composition, based on the total weight of the adhesive composition. 
     
     
         7 . The two-component solventless adhesive composition of  claim 1 , the polyol component further comprising at least one non-amine-initiated polyol selected from the group consisting of a polyester polyol, a polyether polyol, a polycarbonate polyol, a polyacrylate polyol, a polycaprolactone polyol, a polyolefin polyol, a natural oil polyol, and combinations of two or more thereof. 
     
     
         8 . The two-component solventless adhesive composition of  claim 1 , further comprising an additive selected from the group consisting of a tackifier, a plasticizer, a rheology modifier, an adhesion promoter, an antioxidant, a filler, a colorant, a surfactant, a catalyst, a solvent, and combinations of two or more thereof. 
     
     
         9 . The two-component solventless adhesive composition of  claim 1 , wherein the stoichiometric ratio of the isocyanate component to the polyol component is from 3:1 to 1:1. 
     
     
         10 . A method for forming a laminate, comprising:
 forming a solventless adhesive composition by mixing reactants comprising:
 an isocyanate component comprising at least one isocyanate; and 
 a polyol component comprising at least one amine-initiated polyol having a functionality of from 3 to 8 and a hydroxyl number of from 20 to 1,000; 
   applying a layer of the adhesive composition to a surface of a first substrate;   bringing the layer into contact with a surface of a second substrate to form a laminate; and   curing the adhesive composition.   
     
     
         11 . The method for forming a laminate of  claim 10 , wherein the amine-initiated polyol is the reaction product of a C 1 -C 6  alkylene oxide and an amine 
     
     
         12 . The method for forming a laminate of  claim 11 , wherein the alkylene oxide is selected from the group consisting of ethylene oxide, propylene oxide, 1,2-butylene oxide, and combinations of two or more thereof. 
     
     
         13 . The method for forming a laminate of  claim 11 , wherein the amine is selected from the group consisting of toluene diamine, methylamine, ethylenediamine, diethylenetriamine, aniline, aminoethylethanolamine, bis-3-aminopropylmethylamine, propylenediamine, tetra-or hexamethyleneamine, triethanolamine, phenylenediamine, and combinations of two or more thereof. 
     
     
         14 . The method for forming a laminate on of  claim 10 , wherein the amine-initiated polyol accounts for 0.5 to 12 wt % of the polyol component, based on the total weight of the polyol component. 
     
     
         15 . The method for forming a laminate of  claim 10 , the polyol component further comprising at least one non-amine-initiated polyol selected from the group consisting of a polyester polyol, a polyether polyol, a polycarbonate polyol, a polyacrylate polyol, a polycaprolactone polyol, a polyolefin polyol, a natural oil polyol, and combinations of two or more thereof. 
     
     
         16 . The method for forming a laminate of  claim 10 , further comprising adding an additive to the adhesive composition, the additive selected from the group consisting of a tackifier, a plasticizer, a rheology modifier, an adhesion promoter, an antioxidant, a filler, a colorant, a surfactant, a catalyst, a solvent, and combinations of two or more thereof. 
     
     
         17 . The method for forming a laminate of  claim 10 , wherein the first substrate and second substrate are each selected from the group consisting of wood, metal, plastics, composite materials, paper, fabric, and combinations of two or more thereof. 
     
     
         18 . A laminate formed by the method of  claim 10 .