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

Abstract

Two-component solventless polyurethane adhesive compositions comprising an isocyanate component and a polyol component comprising at least one highly-reactive amine-initiated polyol are disclosed. The at least one amine-initiated polyol comprises primary hydroxyl groups and a backbone incorporating one or more tertiary amines. The amine-initiated polyol further comprises a functionality of from 2 to 12, a hydroxyl number of from 5 to 1,830, and a viscosity at 40° C. of from 500 to 20,000 mPa-s. The polyol component can further comprise a non-amine-initiated polyol. The adhesive compositions are formulated such that the isocyanate and polyol components can be applied to separate substrates prior to mixing. Still further, a laminate comprising the adhesive compositions is disclosed.

1 . A 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 comprising two or more primary hydroxyl groups and a backbone incorporating tertiary amines, wherein the amine-initiated polyol comprises a functionality of from 2 to 12, a hydroxyl number of from 5 to 1,830, and a viscosity at 40° C. of from 500 to 20,000 mPa-s.   
     
     
         2 . The two-component solventless adhesive composition according to  claim 1 , wherein the isocyanate component is adapted for application to a first substrate and the polyol component is adapted for application to a second substrate. 
     
     
         3 . The two-component solventless adhesive composition of  claim 1 , the adhesive composition comprising a viscosity greater than 10,000 mPa-s (at 40° C.) within 10 minutes of mixing the isocyanate component and polyol component. 
     
     
         4 . A two-component solventless adhesive composition, comprising:
 an isocyanate component adapted for application to a first substrate and comprising at least one isocyanate; and   a polyol component adapted for application to a second substrate and comprising at least one amine-initiated polyol comprising primary hydroxyl groups and a backbone incorporating tertiary amines   
     
     
         5 . The two-component solventless adhesive composition of  claim 4 , wherein the amine-initiated polyol has the structure I: 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , and R 3  are independently a linear or branched alkyl group. 
       
     
     
         6 . The two-component solventless adhesive composition of  claim 4 , wherein the amine-initiated polyol comprises a functionality of 4. 
     
     
         7 . The two-component solventless adhesive composition of  claim 4 , wherein the amine-initiated polyol comprises a hydroxyl number of 37. 
     
     
         8 . The two-component solventless adhesive composition of  claim 4 , wherein the amine-initiated polyol comprises a viscosity at 25° C. of about 1,200 mPa-s. 
     
     
         9 . The two-component solventless adhesive composition of  claim 4 , wherein the amine-initiated polyol comprise a molecular weight of about 6,000 g/mol. 
     
     
         10 . The two-component solventless adhesive composition of  claim 4 , wherein the ratio by weight of isocyanate component to polyol component is from 0.5:1 to 1.5:1. 
     
     
         11 . The two-component solventless adhesive composition of  claim 4 , wherein the isocyanate component comprises less than about 50% monomer content. 
     
     
         12 . The two-component solventless adhesive composition of  claim 4 , wherein the isocyanate component comprises a viscosity at 40° C. from 500 to 10,000 mPa-s. 
     
     
         13 . The two-component solventless adhesive composition of  claim 4 , wherein the at least one polyisocyanate is selected from the group consisting of 4,4-methylene diphenyl dipolyisocyanate (“MDI”), 2,4-MDI, 2,2′-MDI, 2,4-toluene-dipolyisocyanate (“TDI”), 2,6-TDI, isomers of hexamethylene diisocyanate (“HDI”), and combinations of two or more thereof. 
     
     
         14 . A laminate structure comprising the two-component solventless adhesive composition according to any one of the foregoing claims.