Wood Adhesive Formulation

Abstract

The invention relates to a formulation comprising:—a first component which is formed from at least one isocyanate and at least one polyether, wherein said polyether comprises at least one ethylene oxide moiety and at least one isocyanate-reactive group selected from the group comprising hydroxyl, amino, epoxy, and thiol; and—a second component comprising at least one amino resin, wherein said amino resin is the condensation product of an aldehyde with a compound selected from the group comprising urea, melamine, benzoguanamine, glycoluril, acetoguanamine and mixtures thereof.

1 . An adhesive formulation for bonding lignocellulosic materials comprising:
 a first component which is formed from at least one isocyanate and at least one polyether, wherein said polyether comprises at least one ethylene oxide moiety and at least one isocyanate-reactive group selected from the group comprising hydroxyl, amino, epoxy, and thiol; and   a second component comprising at least one amino resin, wherein said amino resin is the condensation product of an aldehyde with a compound selected from the group comprising urea, melamine, benzoguanamine, glycoluril, acetoguanamine and mixtures thereof.   
     
     
         2 . The formulation according to  claim 1 , wherein said amino resin is the condensation product of a compound as defined in  claim 1  with an aldehyde selected from the group comprising formaldehyde, acetaldehyde, crotonaldehyde, acrolein, benzaldehyde, and furfural. 
     
     
         3 . The formulation according to  claim 1 , wherein the formulation has an ethylene oxide content of at least 1% by weight based on 100% by weight of the at least one isocyanate and the at least one polyether combined. 
     
     
         4 . The formulation according to  claim 1 , wherein the at least one polyether comprises the reaction product obtained by the polymerization of ethylene oxide or the reaction product obtained by the copolymerisation of ethylene oxide with at least one other cyclic oxide, in the presence of at least one polyfunctional initiator selected from the group comprising ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, cyclohexane dimethanol, resorcinol, bisphenol A, glycerol, trimethylolopropane, 1,2,6-hexantriol, pentaerythritol and mixtures thereof. 
     
     
         5 . The formulation according to  claim 1 , wherein the at least one polyether has a weight average molecular weight ranging from 62 to 40000. 
     
     
         6 . The formulation according to  claim 1 , wherein the at least one isocyanate is selected from the group comprising hexamethylene diisocyanate, m- and p-phenylene diisocyanate, tolylene-2,4- and tolylene-2,6-diisocyanate, diphenylmethane diisocyanate in the form of its 2,4′-, 2,2′- and 4,4′-isomers and mixtures thereof, the mixtures of diphenylmethane diisocyanates and oligomers thereof, chlorophenylene-2,4-diisocyanate, naphthylene-1,5-diisocyanate, diphenylene-4,4′-diisocyanate, 4,4′-diisocyanate-3,3′-dimethyl-diphenyl, 3-methyl-diphenylmethane-4,4′-diisocyanate , diphenyl ether diisocyanate, cyclohexane-2,4- and -2,3-diisocyanate, 1-methylcyclohexyl-2,4- and -2,6-diisocyanate, bis-(isocyana-tocyclohexyl)methane, 2,4,6-triisocyanatotoluene, 2,4,4-triisocyanatodiphenylether, isophorone diisocyanate, butylene diisocyanate, trimethylhexamethylene diisocyanate, isocyanatomethyl-1,8-octane diisocyanate, tetramethylxylene diisocyanate, 1,4-cyclohexanediisocyanate, tolidine diisocyanate, and mixtures thereof. 
     
     
         7 . The formulation according to  claim 1 , wherein the at least one amino resin is present in an amount of at least 30% by weight based on 100% by weight of the total formulation. 
     
     
         8 . The formulation according to  claim 1 , wherein the at least one isocyanate is present in an amount of at least 0.5% by weight based on 100% by weight of the total formulation. 
     
     
         9 . The formulation according to  claim 1 , wherein the at least one polyether is present in an amount of at least 0.01% by weight based on 100% by weight of the total formulation. 
     
     
         10 . The formulation according to  claim 1 , wherein the formulation comprises at least one additive selected from the group comprising a hardener, a surfactant, a release agent, a wax, and a pigment. 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . A method for preparing a composition according to  claim 11 , comprising the steps of:
 mixing at least one isocyanate with at least one polyether to prepare a first component as described in  claim 1 ; and   adding to the first component a second component comprising at least one amino resin as described in  claim 1  and mixing thereby forming the composition.   
     
     
         16 . The formulation according to  claim 4 , wherein the at least one other cyclic oxide is propylene oxide.