Protein-containing adhesives, and manufacture and use thereof

Abstract

The invention provides protein adhesives and methods of making and using such adhesives. One type of protein adhesive described herein contains lignin and ground plant meal or an isolated polypeptide composition obtained from plant biomass. Other types of protein adhesives described herein contain a plant protein composition and either a hydroxyaromatic/aldehyde, urea/aldehyde, or amine/aldehyde component.

We claim: 
     
         1 . An adhesive composition comprising:
 (a) lignin;   (b) a plant protein composition; and   (c) a hydroxyl-functional compound.   
     
     
         2 . The composition of  claim 1 , wherein the plant protein composition is derived from corn, wheat, sunflower, cotton, rapeseed, canola, castor, soy, camelina, flax, jatropha, mallow, peanuts, algae, sugarcane bagasse, tobacco, whey, or a combination thereof. 
     
     
         3 . The composition of  claim 1 , wherein the plant protein composition is ground plant meal. 
     
     
         4 . The composition of  claim 3 , wherein the ground plant meal is canola meal, rapeseed meal, or sunflower meal. 
     
     
         5 . The composition of  claim 1 , wherein the plant protein composition is present in an amount of from about 15% w/w to about 35% w/w of the adhesive composition. 
     
     
         6 . The composition of  claim 4 , wherein the plant protein composition is present in an amount of from about 15% w/w to about 35% w/w of the adhesive composition. 
     
     
         7 . The composition of  claim 1 , wherein the lignin has a weight average molecular weight of about 10,000 g/mol to about 70,000 g/mol. 
     
     
         8 . The composition of  claim 1 , wherein the lignin is present in an amount of from about 5% w/w to about 35% w/w of the adhesive composition. 
     
     
         9 . The composition of  claim 1 , wherein the hydroxyl-functional compound is a low-viscosity polyol. 
     
     
         10 . The composition of  claim 1 , wherein the hydroxyl-functional compound is glycerin, propylene glycol, polypropylene glycol, polyethylene glycol, or trimethylol propane. 
     
     
         11 . The composition of  claim 6 , wherein the hydroxyl-functional compound is glycerin, propylene glycol, polypropylene glycol, polyethylene glycol, or trimethylol propane. 
     
     
         12 . The composition of  claim 1 , wherein the hydroxyl-functional compound is glycerin. 
     
     
         13 . The composition of  claim 1 , wherein the hydroxyl-functional compound is polyethylene glycol. 
     
     
         14 . An adhesive composition comprising:
 (a) lignin;   (b) a plant protein composition; and   (c) a polyol.   
     
     
         15 . The composition of  claim 14 , wherein the plant protein composition is ground plant meal. 
     
     
         16 . The composition of  claim 15 , wherein the plant protein composition is ground plant meal derived from corn, wheat, sunflower, cotton, rapeseed, canola, castor, soy, camelina, flax, jatropha, mallow, peanuts, sugarcane bagasse, tobacco, or a combination thereof. 
     
     
         17 . The composition of  claim 16 , wherein the plant protein composition is present in an amount of from about 15% w/w to about 35% w/w of the adhesive composition. 
     
     
         18 . A solid binder composition formed by curing a composition of  claim 1 . 
     
     
         19 . A method of bonding a first article to a second article comprising:
 (a) depositing on a surface of the first article the adhesive composition of  claim 1  thereby to create a binding area; and   (b) contacting the binding area with a surface of the second article thereby to bond the first article to the second article.   
     
     
         20 . An article comprising two or more components bonded together using the adhesive composition of  claim 1 .