Method and composition for priming wood and natural fibres

Abstract

A method of improving the bonding of a coating or adhesive to an article comprising a wood surface comprises applying to the at least part of the wood surface a primer composition comprising a waterborne composition consisting essentially of at least one polyamine, at least one base and water and having a pH of at least 11.5.

1 - 36 . (canceled) 
     
     
         37 . A method of improving the bonding of a coating or adhesive to an article comprising a wood surface comprising applying to the at least part of the wood surface a primer composition comprising a waterborne composition consisting essentially of at least one polyamine, at least one base and water and having a pH of at least 11.5. 
     
     
         38 . A method according to  claim 37 , wherein the pH of the waterborne composition is at least 12.5. 
     
     
         39 . A method according to  claim 37 , wherein the polyamine comprises polymers and copolymers having multi amine groups and of molecular weight is between 200 and 3000000. 
     
     
         40 . A method according to  claim 37 , wherein the polyamine comprises at least one compound selected from the group consisting of polyethyleneimines of molecular weight in the range of from 800 to 2 million. 
     
     
         41 . A method according to  claim 37 , wherein the primer composition contains from 0.05 to 50% polyamine by weight based on the total weight of the composition. 
     
     
         42 . A method according to  claim 37 , wherein the primer composition contains a hydroxide or carbonate base wherein the counter ion of the hydroxide or carbonate comprises at least one of a metal and ammonium cation. 
     
     
         43 . A method according to  claim 37 , wherein the at least one base is selected from the group consisting of alkali and alkaline earth metal hydroxides and carbonates. 
     
     
         44 . A method according to  claim 37 , wherein the base comprises a strong base in an amount of from 0.1% to 10% by weight based on the total weight of the composition. 
     
     
         45 . A method according to  claim 37 , wherein the primer composition is applied to at least part of the wood surface of article by brush, roller coating, spray, curtain coating, dip coating or the like. 
     
     
         46 . A method according to  claim 37 , wherein the primer composition based on polyamine solid content is applied at a rate of 0.01 to 20 g/m2 and most preferably at a rate of 0.1 to 5 g/m2. 
     
     
         47 . A method according to  claims 37 , wherein the primer composition comprises at least one additional component selected from the group consisting of stain-blocking agents, thickeners, resins latex components wetting agents, surfactants, pigments, fillers, functional materials such as UV stabilisers, fire retardants, biocides and preservatives, and cross linkers containing at least two functional groups with at least one of these groups capable of reacting with the amino groups of the polyamino compounds so that a stable bond is formed between the polyamino compound and the crosslinker. 
     
     
         48 . A method according to  claim 37 , wherein the method further comprises application of a coating or adhesive to at least part of the primed wood surface. 
     
     
         49 . A method according to  claim 37 , wherein the method comprises applying at least one coating selected from the group consisting of coatings based on any of vegetable oils; alkyds and modified alkyds such as vinyl toluenated alkyds, styrenated alkyds, urethane alkyds, polyesters; cellulosic derivatives such as ethyl cellulose, nitrocellulose, cellulose acetobutyrate and modifications such as cellulose acrylics, cellulose alkyds and cellulose polyurethanes and latex coatings based on urethane series resins, melamine series resins and polyester series resins or lacquers. 
     
     
         50 . A method according to  claim 37 , wherein the method further comprises applying to at least a portion of the primed wood surface at least one thermoset or thermoplastic adhesive selected from epoxies, polyurethanes, isocyanates, urea formaldehydes, phenolics, acrylics, PVA's, crosslinked PVA's, polyesters, silicones, hot-melts, cyanoacrylates and hybrids of any of these materials. 
     
     
         51 . A method according to  claim 37 , wherein following application of said waterborne composition a powder coating is applied by an electrostatic spray process.