Binder compositions comprising lignin derivatives

Abstract

The present disclosure provides an adhesive composition comprising derivatives of native lignin and an isocyanate-based binder such as methylene diphenyl diisocyanate. The present compositions may further comprise formaldehyde-based resins such as PF, UF, and MF. While not wishing to be bound by theory, it is believed that incorporating derivatives of native lignin in isocyanate compositions will reduce incidence of pre-curing.

What is claimed is: 
     
         1 . An adhesive system comprising:
 a. a resin comprising at least about 30% by weight of phenol-formaldehyde resin and at least about 30% by weight of derivative of native lignin; and   b. an isocyanate-based binder.   
     
     
         2 . A composition according to  claim 1  wherein the composition comprises at least about 35% by weight of derivative of native lignin. 
     
     
         3 . A composition according to  claim 1  wherein the derivative of native lignin has an ethoxy content of 0.45 mmol/g or greater. 
     
     
         4 . A composition according to  claim 1  wherein the isocyanate-based binder comprises methylene diphenyl diisocyanate. 
     
     
         5 . A composition according to  claim 1  wherein the isocyanate-based binder comprises methylene diphenyl diisocyanate and a derivative of native lignin. 
     
     
         6 . A composition according to  claim 1  wherein the isocyanate-based binder comprises methylene diphenyl diisocyanate and a derivative of native lignin wherein the derivative of native lignin has an aliphatic hydroxyl content of from about 0.6 mmol/g to about 6.5 mmol/g. 
     
     
         7 . Use of the system according to  claim 1  for the production of a fibreboard. 
     
     
         8 . Use of the system according to  claim 1  as an adhesive for low density fibreboard (LDF), medium density fibreboard (MDF), high density fibreboard (HDF), strawboard & other agricultural fibre/particle boards, oriented strand board (OSB), particle board, wood fibre insulation board (WFIB), or polyurethane foams. 
     
     
         9 . A method of producing a fibreboard
 a) providing fibres to a blowline;   b) providing an adhesive system according to  claim 1 ;   c) treating the fibres with the adhesive;   d) preferably at least partially drying the treated fibres; and   e) pressing the treated fibres to form a fibreboard.   
     
     
         10 . A binder composition comprising methylene diphenyl diisocyanate and a derivative of native lignin. 
     
     
         11 . A composition according to  claim 10  wherein the derivative of native lignin has an aliphatic hydroxyl content of from about 0.1 mmol/g to about 8 mmol/g. 
     
     
         12 . A composition according to  claim 10  wherein the derivative of native lignin has an aliphatic hydroxyl content of from about 0.6 mmol/g to about 6.5 mmol/g 
     
     
         13 . A composition according to  claim 10  comprising from about 0.1% to about 25%, by weight, of the derivative of native lignin. 
     
     
         14 . A composition according to  claim 10  comprising from about 50% to about 99%, by weight, of methylene diphenyl diisocyanate. 
     
     
         15 . A method of producing a composition according to  claim 10 , said method comprising:
 a) providing a composition comprising derivatives of native lignin in a suitable solvent;   b) providing a resin composition comprising methylene diphenyl diisocyanate;   c) mixing the compositions; and   d) removing the solvent.   
     
     
         16 . A fibreboard comprising a composition according to  claim 10 . 
     
     
         17 . Use of a composition according to  claim 10  as a binder for low density fibreboard (LDF), medium density fibreboard (MDF), high density fibreboard (HDF), strawboard & other agricultural fibre/particle boards, oriented strand board (OSB), particle board, wood fibre insulation board (WFIB), or polyurethane foams. 
     
     
         18 . A method of producing a fibreboard
 f) providing fibres to a blowline;   g) providing a binder comprising methylene diphenyl diisocyanate and a derivative of native lignin;   h) treating the fibres with the binder;   i) preferably at least partially drying the treated fibres; and   j) pressing the treated fibres to form a fibreboard.