Water-resistant vegetable protein adhesive dispersion compositions
AssigneesHeartland Resource Technologies LLC, Usda
InventorsJames M. Wescott, Charles R. Frihart
Life of this patent
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Abstract
Water-resistant, protein-based adhesive dispersion compositions and methods for preparing them are provided. The adhesive dispersions are prepared by copolymerizing a denatured vegetable protein, such as soy flour, that has been functionalized with methylol groups with one or more reactive comonomers, and preparing an acidic dispersion of the adhesive. The adhesive dispersions exhibit superior water resistance, and can be used to bond wood substrates, such as panels or laminate, or in the preparation of composite materials.
Claims19
A method of preparing a protein-based adhesive dispersion, the method comprising the steps of:
- denaturing a protein, whereby a denatured protein is obtained;
- methylolating the denatured protein with a formaldehyde source, whereby a methylolated, denatured protein is obtained;
- copolymerizing the methylolated denatured protein with a comonomer under basic conditions to yield a protein-based adhesive, wherein the comonomer is selected from phenol, phenol formaldehyde, urea, urea formaldehyde, melamine, melamine formaldehyde, melamine urea formaldehyde, and mixtures thereof;
- and adding an acid to the protein-based adhesive until a pH of less than 6.0 is attained, whereby a protein-based adhesive dispersion is obtained.
An adhesive dispersion comprising an acid and an adhesive, wherein the acid is present in an amount sufficient to obtain a pH less than 6.0, and wherein the adhesive comprises a methylolated protein resulting from reacting a copolymer of a protein having a plurality of methylol groups and at least one comonomer, wherein the comonomer comprises a methylol compound selected from phenol, phenol formaldehyde, urea, urea formaldehyde, melamine, melamine formaldehyde, melamine urea formaldehyde, tetramethylol ketone and mixtures thereof, wherein the dispersion comprises less than 2.5 wt. % of free phenol and less than about 1 wt. % free formaldehyde.
Dependencies are inferred from the claim text.