BR112016013955B1 - AQUEOUS COMPOSITION OF ADHESIVE, ITS PRODUCTION PROCESS, LIGNOCELLULOSIC COMPOSITE AND PROCESS FOR THE PRODUCTION OF THE SAME - Google Patents

Abstract

AQUEOUS ADHESIVE COMPOSITION, ITS PRODUCTION PROCESS, PRECURSOR COMPOSITION, ITS PRODUCTION PROCESS, LIGNOCELLULOSIC SUBSTRATE AND PROCESS FOR THE PRODUCTION OF LIGNOCELLULOSIC COMPOSITE. The present invention relates to an aqueous adhesive composition and a process for preparing said compositions. The composition comprises a macromolecular complex comprising (A) a first component comprising (i) a framework element and (ii) a polyphenol, and (B) a second component comprising a polypeptide, an oligopeptide, an amino acid, or a polyamine. The framework element comprises (a) a polypeptide, an oligopeptide, an amino acid, or a polyamine, (b) a polysaccharide, an oligosaccharide, or a monosaccharide, or a saccharide conjugate, or (c) a lignin, a lignan, or a lignin conjugate. The polyphenol comprises a tannin, a tannic acid, a flavonoid, or a polyresorcinol. The present invention also relates to an adhesive precursor composition comprising the first component.

Description

FIELD OF THE INVENTION

[001] The invention relates to adhesives that are particularly convenient for use in the manufacture of lignocellulosic composites such as plywood, medium density fiberboard, particle board and veneers and for use in wood adhesion and packaging, and to a process for the manufacture of said composites.

BACKGROUND

[002] Medium density fiberboard, particle board, and other panel boards, plywood and veneer and similar manufactured wood products are typically composed of small-sized lignocellulosic or cellulosic material - either as particles or sheets - combined with an adhesive or with a resin with the composition subsequently pressed or shaped into a panel or the like and heated to cure the adhesive in order to fix the shape and provide internal bonding.

[003] In industry, the adhesives that are most commonly used are urea formaldehyde (UF) resins and phenol formaldehyde resins. Isocyanate resins are also used. Phenolic resins provide composite materials with superior material properties including stability, hardness and water resistance. UF resins provide good strength and are extremely cost-competitive. But both resins have disadvantages. Both are synthetic resins derived from fossil fuels and both result in the formation and emission of volatile organic compounds, particularly formaldehyde, both during manufacture and during use of the resulting panels.

[004] A resin that retains the material properties of UF and phenolic resins but is formaldehyde-free and produced from renewable or mostly renewable resources would potentially be of great benefit to the wood composite industry, to users of wood composites, to interior living spaces and to the environment. Ideally any similar resin would be compatible with current plant and production schemes particularly with regard to issues such as handling and application, compression and curing of the resins. Ideally, it would also be able to be formulated using typical adhesive manufacturing practice.

[005] It is an object of the invention to provide an adhesive suitable for bonding wood and other lignocellulosic substrates that is preferably free of formaldehyde or can be used to reduce formaldehyde emissions, and substantially consisting of renewable materials, or at least provide the public with a useful choice.

SUMMARY OF THE INVENTION

[006] In one aspect the present invention provides an aqueous adhesive composition comprising, consisting of, or consisting essentially of a macromolecular complex, the complex comprising:

[007] (A) a first component comprising:

[008] (i) a frame element selected from among

[009] (a) a polypeptide, oligopeptide, amino acid, polyamine, or any combination of any two or more thereof,

[0010] (b) a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof, or a saccharide conjugate comprising a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof and a first linker molecule, and

[0011] (c) a lignin, a lignan or a lignin conjugate comprising a lignin and a second linker molecule; It is

[0012] (ii) a polyphenol comprising a tannin, a tannic acid, a flavonoid, a polyresorcinol or any combination of any two or more thereof; It is

[0013] (B) a second component comprising a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof.

[0014] Any of the following embodiments may apply to any of the aspects described herein, in this patent application.

[0015] In one embodiment, the structure element to polyphenol ratio is from about 20:1 to about 1:1, from about 20:1 to about 2:1, from about 15:1 to about 1:1, from about 15:1 to about 2:1, from about 10:1 to about 2:1, from about 10:1 to about 1:1, from about 7:1 to about 2:1, from about 7:1 to about 3:1, from about 6:1 to about 2:1, from about 6:1 to about 3:1, from about 5:1 to about 3:1, from about 4:1 to about 3:1, about 4:1 or about 3:1 per dry weight.

[0016] In one embodiment, the ratio of structure element (a) to polyphenol is from about 15.5:1 to about 2:1 by dry weight. In another embodiment, the ratio of structure element (a) to polyphenol is about 3.9:1 by dry weight.

[0017] In one embodiment, the ratio of structure element (b) to polyphenol to second component is about 3 to 5:1:5.6 by dry weight.

[0018] In one embodiment, the ratio of structure element (c) to polyphenol is from about 3:1 to about 7:1 by dry weight. In some embodiments, the ratio is 5:1 by dry weight.

[0019] In one embodiment, the ratio of structure element (d) to polyphenol is from about 7:1 to about 2:1 by dry weight. In another embodiment, the ratio of structure element (c) to polyphenol is from about 6.3:1 to about 2.6:1 by dry weight. In another embodiment, the ratio of structure element (c) to polyphenol is from about 5.3:1 to about 3:1 by dry weight. In another embodiment, the ratio of structure element (c) to polyphenol is about 3.2:1 by dry weight.

[0020] In one embodiment, the polyphenol to second component ratio is from about 1:1 to about 1:8, from about 1:2 to about 1:8, from about 1:1 to about 1:7, from about 1:2 to about 1:7, from about 1:3 to about 1:7, from about 1:1 to about 1:7 6, from about 1:2 to about 1:6, from about 1:3 to about 1:6, about 1:6, about 1:5, about 1:4, about 1:3, or about 1:2,

[0021] In one embodiment, the ratio of polyphenol to second component is from about 1:2 to about 1:6 by dry weight. In another embodiment, the ratio of polyphenol to second component is about 1:2.8 by dry weight.

[0022] In one embodiment, the ratio of second component to polyphenol is from about 3:1 to about 7:1 by dry weight. In another embodiment, the second component to polyphenol ratio is from about 2.8:1 to about 6.7:1. In another embodiment, the second component to polyphenol ratio is about 5.5:1.

[0023] In one embodiment, the ratio of second component to polyphenol is from about 2:1 to about 7:1 by dry weight. In some embodiments, the ratio of second component to polyphenol is about 5.6:1 by dry weight.

[0024] In some embodiments, the saccharide conjugate comprises a plurality of first linker molecules which may be the same or different.

[0025] In some embodiments, the lignin conjugate comprises a plurality of second linker molecules which may be the same or different.

[0026] In one embodiment, the first linker molecule and the second linker molecule are each independently selected from:

[0027] (a) a polypeptide, an oligopeptide, an amino acid, or any combination of any two or more thereof;

[0028] (b) an inorganic polyhydroxylated non-metallic compound or an ester or a salt thereof;

[0029] (c) an amine compound or a salt thereof;

[0030] (d) a thiol compound or a salt thereof;

[0031] (e) a metal ion;

[0032] (f) an aldehyde compound; or a carboxylic acid compound or a salt, ester, anhydride, or halide thereof; It is

[0033] (g) any combination of any two or more thereof, for example any three, four, five, or six or more thereof.

[0034] In some embodiments, the first linker molecule and the second linker molecule are each independently selected from (a) through (g), where (f) is an aldehyde compound.

[0035] In some embodiments, the first linker molecule and/or the second linker molecule independently comprise two or more, for example three, four, five, or more, linker molecules adjacent to one another, preferably where the linker molecules are selected from (a) to (f).

[0036] In some embodiments, the saccharide conjugate comprises a first linker molecule comprising two or more, for example three, four, five, or more, linker molecules selected from (a) to (f) adjacent to each other.

[0037] In some embodiments, the lignin conjugate comprises a second linker molecule comprising two or more, for example three, four, five, or more, linker molecules selected from (a) to (f) adjacent to one another.

[0038] In one embodiment, the first chainer molecule is selected from:

[0039] (b) an inorganic polyhydroxylated non-metallic compound or an ester or a salt thereof; It is

[0040] (e) a metal ion;

[0041] (g) any combination of any two or more thereof.

[0042] In another embodiment, the first linker molecule is an inorganic polyhydroxy nonmetallic compound or an ester or salt thereof.

[0043] In one embodiment, the inorganic polyhydroxylated nonmetallic compound or ester or salt thereof is a polyhydroxylated boron, phosphorus, silicon, or sulfur compound or an ester or salt thereof. In another embodiment, the inorganic polyhydroxy nonmetallic compound or ester or salt thereof is a polyhydroxy boron or phosphorus compound or an ester or salt thereof.

[0044] In one embodiment, the inorganic polyhydroxy nonmetallic compound or ester or salt thereof is a boron or phosphorus oxoacid comprising two or more hydroxyl groups or an ester or salt thereof. In one embodiment, the oxo acid is a boron or phosphorus ortho acid or an ester or salt thereof.

[0045] In one embodiment, the inorganic polyhydroxy nonmetallic compound or ester or salt thereof is boric acid, phosphoric acid, or an ester or salt thereof. In one embodiment, the inorganic polyhydroxy nonmetallic compound or ester or salt thereof is boric acid, or an ester or salt thereof.

[0046] In one embodiment, the metal ion is capable of forming a metal chelate on the saccharide conjugate or on the lignin conjugate.

[0047] In one embodiment, the metal ion is an ion of a metal selected from groups 1 to 15 of the periodic table. In another embodiment, the metal is selected from periods 2 to 6 of groups 1 and 2, periods 4 to 6 of groups 3 to 12, periods 3 to 6 of group 13, or periods 4 to 6 of groups 14 and 15.

[0048] In one embodiment, the metal is an alkali metal, an alkaline earth metal, a transition metal, or a base metal.

[0049] In one embodiment, the metal is lithium, sodium, potassium, magnesium, calcium, barium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, zirconium, molybdenum, rhodium, silver, tungsten, osmium, rhenium, iridium, aluminum, lead, or bismuth. In another embodiment, the metal is lithium, sodium, potassium, magnesium, calcium, barium, titanium, chromium, manganese, iron, cobalt, copper, zinc, aluminum, lead, or bismuth. In another embodiment, the metal is lithium, sodium, potassium, magnesium, calcium, titanium, chromium, manganese, iron, cobalt, copper, zinc, aluminum, or lead. In another embodiment, the metal is calcium, chromium, iron, copper, zinc, or aluminum.

[0050] In some embodiments, the ratio of polyphenol to first linker molecule is from about 5:1 to about 40:1 by dry weight. In some embodiments, the ratio is from about 5:1 to about 30:1, from about 5:1 to about 20:1, from about 5:1 to about 10:1, from about 10:1 to about 40:1, from about 10:1 to about 30:1, or from about 10:1 to about 20:1.

[0051] In some embodiments, the second linker molecule is selected from:

[0052] (a) a protein, a polypeptide, an oligopeptide, an amino acid, or any combination of any two or more thereof;

[0053] (c) an amine compound or a salt thereof;

[0054] (d) a thiol compound or a salt thereof;

[0055] (f) an aldehyde compound; or a carboxylic acid compound or a salt, ester, anhydride or halide thereof; It is

[0056] (g) any combination of any two or more thereof, for example any three or four or more thereof.

[0057] In some embodiments, the second linker molecule is selected from (a), (c), (d), (f), and (g) above, wherein (f) is an aldehyde compound.

[0058] In some embodiments, the second linker molecule is selected from:

[0059] (a) a protein, a polypeptide, an oligopeptide, an amino acid, or any combination of any two or more thereof; It is

[0060] (c) an amine compound or a salt thereof

[0061] (f) an aldehyde compound; or a carboxylic acid compound or a salt, ester, anhydride or halide thereof; It is

[0062] (g) any combination of any two or more thereof.

[0063] In some embodiments, the second linker molecule is selected from (a), (c), (f), and (g) above, wherein (f) is an aldehyde compound.

[0064] In some embodiments, the second linker molecule is selected from:

[0065] (a) a protein, a polypeptide, an oligopeptide, an amino acid, or any combination of any two or more thereof; It is

[0066] (c) an amine compound or a salt thereof; It is

[0067] (g) any combination of any two or more thereof.

[0068] In some embodiments, the second linker molecule comprises two or more, for example three, four, five, or more, linker molecules selected from (b), (e) and a carboxylic acid compound or a salt, an ester, anhydride or a halide thereof adjacent to each other.

[0069] In some embodiments, the second linker molecule comprises an inorganic polyhydroxy nonmetallic compound or ester or salt thereof and a carboxylic acid compound or a salt, ester, anhydride or halide thereof adjacent thereto.

[0070] In one embodiment, the amine compound comprises at least 2 carbon atoms.

[0071] In one embodiment, the amine compound comprises an amino group and at least one additional functional group capable of forming covalent or non-covalent bonds in the saccharide conjugate or in the lignin conjugate. In another embodiment, the at least one additional functional group is selected from the group consisting of amino, hydroxyl, and carboxyl.

[0072] In one embodiment, the amine compound is selected from a natural amino acid, an unnatural amino acid having at least 2 carbon atoms, a polyamine having at least 2 carbon atoms, and a hydroxyamine having at least 2 carbon atoms, or a salt thereof. In one embodiment, the polyamine is a diamine.

[0073] In some embodiments, the amine compound comprises from about 2 to about 12, from about 2 to about 10, from about 2 to about 8, or from about 2 to about 6 carbon atoms.

[0074] In some embodiments, the natural amino acid is lysine.

[0075] In one embodiment, the thiol compound comprises a thiol group and at least one additional functional group capable of forming covalent or non-covalent bonds in the saccharide conjugate or lignin conjugate. In another embodiment, the at least one additional functional group is selected from the group consisting of thiol, amino, hydroxyl, and carboxyl.

[0076] In one embodiment, the thiol compound comprises at least two carbon atoms. In one embodiment, the thiol compound is cysteine, a compound having at least two carbon atoms comprising a thiol group and at least one additional functional group selected from thiol, amino, hydroxyl, and carboxyl, or a salt thereof.

[0077] In some embodiments, the thiol compound comprises from about 2 to about 12, from about 2 to about 10, from about 2 to about 8, or from about 2 to about 6 carbon atoms.

[0078] In some embodiments, the ratio of lignin to second linker molecule is from about 10:1 to about 1:5, from about 10:1 to about 1:4, from about 10:1 to about 1:2, from about 10:1 to about 1:1, from about 9:1 to about 1:2, from about 1:2 from about 9:1 to about 1:1, from about 8:1 to about 1:2, from about 8:1 to about 1:1, from about 7:1 to about 1:2, from about 7:1 to about 1:1, from about 6:1 to about 1:2, from about 6:1 to about 1:1, from about 5:1 1 to about to about 2:1, from about 5:1 to about 1:1 by dry weight.

[0079] In some embodiments, the ratio of lignin to second linker molecule (c) is from about 10:1 to about 1:1 by dry weight. In some embodiments, the ratio of lignin to second linker molecule (c) is about 3:1 by dry weight.

[0080] In some embodiments, the ratio of second linker molecule (a) to lignin is from about 4:1 to about 1:2 by dry weight. In some embodiments, the ratio of second linker molecule (a) to lignin is from about 3.7:1 to about 0.74:1. In some embodiments, the ratio of second linker molecule (a) to lignin is about 1.2:1.

[0081] In some embodiments, the ratio of second linker molecule (a) to polyphenol is from about 1:1 to about 5:1 by dry weight. In some embodiments, the ratio of second linker molecule (a) to polyphenol is from about 1.9:1 to about 4.7:1. In some embodiments, the ratio of second linker molecule (a) to polyphenol is from about 2.3:1 to about 3.9:1. In some embodiments, the ratio of second linker molecule (a) to polyphenol is about 3.9:1.

[0082] In some embodiments, the ratio of second linker molecule (a) to lignin to polyphenol to second component is about 2 to 5:2 to 5:1:3 to 7 by dry weight. In some embodiments, the ratio of second linker molecule (a) to lignin to polyphenol to second component is about 1.9 to 4.7:2 to 5:1:2.8 to 6.7 or 3.6:3:1:5.6 by dry weight.

[0083] In one embodiment, the second component, framework element (a), first linker molecule, or second linker molecule comprises a polypeptide or oligopeptide. In some embodiments, the polypeptide or oligopeptide comprises at least about 2, 3, 5, 10, 20, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, or 550 amino acids. In some embodiments, the polypeptide or oligopeptide comprises from about 2 to about 550, from about 3 to about 550, from about 5 to about 550, from about 10 to about 550, from about 2 to about 500, from about 3 to about 500, from about 5 to about 500 , or from about 10 to about 500 amino acids.

[0084] In some embodiments, the polypeptide or oligopeptide is a natural or synthetic polypeptide or oligopeptide. In some embodiments, the natural polypeptide or oligopeptide is a plant or animal polypeptide or oligopeptide.

[0085] In some embodiments, the polypeptide or oligopeptide is a meat, fish, dairy, egg, or plant polypeptide or oligopeptide.

[0086] In some embodiments, the polypeptide or oligopeptide is a zein, soy, keratin, gluten, casein, or whey polypeptide or oligopeptide, or any combination of any two or more thereof.

[0087] In some embodiments, the polypeptide is a protein. In some embodiments, the polypeptide is a meat, fish, dairy, egg, or plant protein. In some embodiments, the protein is a zein protein or a soy protein.

[0088] In some embodiments, the element of structure (a) is a zein protein. In some embodiments, the second component is a soy protein.

[0089] In some embodiments, the second linker molecule (a) is a zein protein.

[0090] In some embodiments, the protein is denatured.

[0091] In one embodiment, the adhesive additionally comprises a protein denaturing agent.

[0092] In some embodiments, the denaturing agent is selected from the group consisting of organic solvents, salts, ureas and salts thereof, guanidines and salts thereof, thiols and salts thereof, surfactants, dispersants, and any combination of any two or more thereof.

[0093] In one embodiment, the organic solvent is a polar protic or aprotic solvent. In one embodiment, the organic solvent is an alcohol. In one embodiment, the alcohol is glycerol. In one embodiment, the salts are selected from metal salts, inorganic non-metallic salts, and organic compound salts. In one embodiment, the salt has high solubility in water.

[0094] In one embodiment, the metal salt is an alkali or alkaline earth metal salt. In one embodiment, the metal salt is a sodium salt. In one embodiment, the sodium salt is sodium chloride, sodium sulfite, sodium sulfate, sodium acetate, sodium formate, or sodium bisulfite. In some embodiments, the adhesive composition comprises a denaturing agent comprising sodium sulfite.

[0095] In one embodiment, the inorganic non-metallic salt or salt of an organic compound is selected from amine, ammonium, organic nitrogen, and phosphate salts.

[0096] In some embodiments, the polyamine is selected from organic compounds comprising two or more amine groups. In some embodiments, the polyamine is selected from aliphatic or aromatic compounds comprising two or more amine groups. In some embodiments, the polyamine comprises at least two carbon atoms. In some embodiments, the polyamine comprises from about 2 to about 100, from about 2 to about 150, from about 2 to about 100, from about 2 to about 75, from about 2 to about 50, from about 2 to about 25 carbon atoms.

[0097] In some embodiments, the polyamine is a polymer comprising monomers of an aliphatic or aromatic compound comprising two or more amine groups. In some embodiments the monomers comprise at least 2 carbon atoms. In some embodiments, the monomers comprise from about 2 to about 20, from about 2 to about 15, from about 2 to about 12, from about 2 to about 10, from about 2 to about 8, or from about 2 to about 6 carbon atoms.

[0098] In some embodiments, the polyamine comprises a linear or substantially linear chain of carbon atoms. In some embodiments, the polyamine comprises a straight or substantially straight aliphatic chain comprising from about 2 to about 12, from about 2 to about 10, from about 2 to about 8, or from about 2 to about 6 carbon atoms.

[0099] In some embodiments, the aldehyde or carboxylic acid compound comprises from about 1 to about 12, from about 1 to about 10, from about 1 to about 8, from about 1 to about 6, from about 2 to about 12, from about 2 to about 10, from about 2 to about 8, from about 2 2 to about 6 carbon atoms. In some embodiments, the aldehyde is formaldehyde or an aliphatic or aromatic compound comprising from 2 to 12 carbon atoms and two or more aldehyde groups.

[00100] In some embodiments, the carboxylic acid compound, or salt, ester, anhydride or halide thereof, comprises or is capable of providing in conjugation at least one additional functional group capable of forming covalent or non-covalent bonds in the saccharide conjugate or lignin conjugate.

[00101] In some embodiments, the carboxylic acid compound, or salt, ester, anhydride or halide thereof is selected from formic acid, carbonic acid, or salt, ester, anhydride or halide thereof; an aliphatic or aromatic compound comprising the carboxylic acid group, or a salt, an ester, or an anhydride thereof and having at least two carbon atoms, for example from 2 to 12, 2 to 10, 2 to 8, or 2 to 6 carbon atoms.

[00102] In some embodiments, the aliphatic or aromatic compound is a cyclic ester or cyclic anhydride having at least 3 carbon atoms, preferably at least 4 carbon atoms, for example from 3 to 8, 4 to 8, 4 to 7, or 4 to 6 carbon atoms; or an aliphatic or aromatic compound comprising the carboxylic acid group, or a salt, an acyclic ester, or an acyclic anhydride thereof having at least two carbon atoms, for example from 2 to 12, 2 to 10, 2 to 8, or 2 to 6 carbon atoms and further comprising at least one additional functional group selected from thiol, amino, hydroxyl, and carboxyl.

[00103] In some embodiments, the aliphatic or aromatic compound is a polycarboxylic acid, for example a dicarboxylic acid, having at least two carbon atoms for example from 2 to 12, 2 to 10, 2 to 8, or 2 to 6 carbon atoms, or a salt thereof; or a cyclic anhydride having at least 4 carbon atoms, preferably at least 5 carbon atoms, for example from 4 to 8, 4 to 7, or 4 to 6 carbon atoms.

[00104] In some embodiments the halide is an acid chloride, an acid bromide, or an acid iodide, preferably an acid chloride or an acid bromide, more preferably an acid chloride.

[00105] In some embodiments, the carboxylic acid compound, or a salt, ester, anhydride, or halide thereof is a carboxylic acid compound, or a salt, ester, or anhydride thereof.

[00106] In some embodiments, the second linker molecule comprises two or more, for example three, four, five, or more, linker molecules selected from (c) and aldehyde compound adjacent to each other.

[00107] In some embodiments, the second linker comprises both an amine compound and an aldehyde. In some embodiments, the second linker molecule comprises an amine compound and an aldehyde compound adjacent thereto.

[00108] In one embodiment, the structure element (b) comprises a polysaccharide or an oligosaccharide. In some embodiments, the polysaccharide or oligosaccharide comprises at least about 2, 3, 5, 10, 20, 50, 100, 200, 300, 400, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1250, 1500, or 2000 monosaccharide units. In some embodiments, the polysaccharide or oligosaccharide comprises from about 2 to about 2000, from about 3 to about 2000, from about 5 to about 2000, from about 10 to about 2000, from about 2 to about 1500, from about 3 to about 1500, from about 5 to about 1500, from about 10 to about 1500 monosaccharide units.

[00109] In some embodiments, the polysaccharide or oligosaccharide has a molecular weight of less than 50,000 Daltons. In some embodiments, the molecular weight is from about 1,500 to about 50,000 Daltons.

[00110] In some embodiments, the structure element (b) comprises a polysaccharide.

[00111] In some embodiments, the polysaccharide is a natural polysaccharide or a modified polysaccharide. In some embodiments, the natural polysaccharide is an animal, plant, or microbial polysaccharide.

[00112] In some embodiments, the polysaccharide is selected from the group consisting of starches, oxidized starches, hydrolyzed starches, gums, celluloses, hemicelluloses, dextrins, dextrans, glycogens, chitosans, chitins, aminopolysaccharides, glycoproteins, and any combination of any two or more thereof.

[00113] In some embodiments, the monosaccharide is glucosamine.

[00114] In some embodiments, the structure element (c) comprises a lignin.

[00115] In some embodiments, the lignin has a molecular weight from about 2,000 to about 300,000, from about 5,000 to about 300,000, from about 2,000 to about 100,000, or from about 5,000 to about 100,000 Daltons.

[00116] In some embodiments, the lignin is a chemically modified lignin.

[00117] In some embodiments, the structure element (c) comprises a lignan.

[00118] In one embodiment, the polyphenol comprises a tannin, or a tannic acid. In another embodiment, the polyphenol comprises a tannin.

[00119] In one embodiment, the polyphenol additionally comprises lignin. In one embodiment, the polyphenol comprises a complex of tannin and lignin.

[00120] In some embodiments, the polyphenol comprises a tannin or a mixture of a tannin and a lignin. In some embodiments, the polyphenol comprises a tannin or a complex of tannin and lignin.

[00121] In some embodiments, the adhesive composition comprises at least about 1, 2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 8 5, 90, 95% by weight macromolecular complex. In some embodiments, the solids content is from about 5 to about 99%, from about 10 to about 99%, from about 5 to about 95%, or from about 10 to about 95%.

[00122] In some embodiments, the adhesive composition has a viscosity of at least about 5 cP, at least about 10 cP, at least about 25 cP, at least about 50 cP, at least about 75 cP, at least about 100 cP, or at least about 125 cP. In some embodiments, the viscosity is less than about 100,000 cP, less than about 75,000 cP, less than about 50,000 cP, less than about 25,000 cP, less than about 10,000 cP, less than about 7,500 cP, or less than about 5,000 cP. In some embodiments, the viscosity is from about 5 to about 100,000 cP, from about 10 to about 75,000 cP, from about 10 to about 50,000 cP, from about 25 to about 25,000 cP, from about 25 to about 10,000 cP, from about 50 cP to about 10,000 cP, from about 75 to about 10,000 cP, from about 100 to about 10,000, from about 25 to about 7,500 cP, from about 50 to about 7,500 cP, from about 100 to about 7,500 cP, from about 100 to about 7,500 cP, from about 25 to about 5,000 cP, from about 50 to about 5,000 cP, from about 75 to about 5,000 cP, or from about 100 to about 5,000 cP.

[00123] In some embodiments, the first component is covalently or non-covalently linked to the second component.

[00124] In some embodiments, the structure element is covalently or non-covalently linked to the polyphenol; and the polyphenol is covalently or non-covalently linked to the second component.

[00125] In some embodiments, the polyphenol is bound by covalent or non-covalent bonding between oxygen-containing functional groups of the polyphenol and the structure element and covalent or non-covalent bonding between functional groups of the oxygen-containing polyphenol and the second component.

[00126] In some embodiments, the functional groups of the oxygen-containing polyphenol comprise hydroxyl, carboxylic acid, ester, ether, ketone, or aldehyde groups. In some embodiments, the oxygen-containing functional groups comprise hydroxyl, carboxylic acid, ester, and ether groups.

[00127] In some modalities:

[00128] (a) the first component is covalently or non-covalently bound to the second component,

[00129] (b) the polyphenol is covalently or non-covalently bound to the structure element,

[00130] (c) the polyphenol is covalently or non-covalently bound to the second component,

[00131] (d) the polysaccharide, oligosaccharide, monosaccharide, or any combination of any two or more thereof of the saccharide conjugate is covalently or non-covalently attached to the first linker molecule, or

[00132] (e) the lignin of the lignin conjugate is covalently or non-covalently linked to the second linker molecule, or

[00133] (f) any combination of any two or more thereof.

[00134] In one embodiment, the composition comprises one or more additives selected from the group consisting of organic solvents, surfactants, dispersants, viscosity modifiers, and hydrophobizing agents.

[00135] In some embodiments, the one or more additives provide water resistance to or enhance the water resistance of a lignocellulosic substrate comprising the adhesive. In some embodiments, the one or more additives are selected from metal salts, for example soluble and insoluble metal salts including but not limited to zinc, magnesium, aluminum, and calcium salts, such as carbonates (for example calcium carbonate), which provide water resistance to or enhance the water resistance of a lignocellulosic substrate comprising the adhesive.

[00136] In one embodiment, the additive is a polyol, a fatty acid or an ester or salt thereof, an inorganic polyhydroxy nonmetallic compound or an ester or salt thereof, or a metal ion. In one embodiment, the polyol comprises at least two carbon atoms. In another embodiment, the polyol comprises from 2 to 10 carbon atoms. In some embodiments, the polyol is glycerol.

[00137] In one embodiment, the inorganic polyhydroxylated non-metallic compound or an ester or a salt thereof or a metal ion are as defined in any of the embodiments described herein, with respect to the first or second linker molecule.

[00138] In some embodiments, the adhesive has or provides:

[00139] (a) an internal bond strength of at least about 0.45 MPa when tested in accordance with AS/NZS:4266;

[00140] (b) a density of at least about 600 kg/m3 when assessed in accordance with AS/NZS:4266;

[00141] (c) an average maximum load value of at least about 1250 N when tested in accordance with ASTM D906-98;

[00142] (d) a tensile stress of at least about 2 MPa when tested in accordance with ASTM D906-98;

[00143] (e) a satisfactory chisel test glue line bond rating when tested in accordance with AS/NZS 2098.2:2006 B;

[00144] (f) formaldehyde emissions of less than 0.5 mg/L when tested in accordance with AS/NZS 4266:2004 after 7 days of conditioning; or

[00145] (g) any combination of any two or more thereof.

[00146] In some embodiments, the internal bond strength is at least about 0.5, about 0.55, about 0.6, or about 0.65 MPa.

[00147] In some embodiments, the density is at least about 650, about 700, or about 750 kg/m3.

[00148] In some embodiments, formaldehyde emissions are less than about 0.45, about 0.4, about 0.35, about 0.3 mg/L, about 0.25 mg/L, about 0.2 mg/L, about 0.15 mg/L, or about 0.1 mg/L.

[00149] In some embodiments, the pH of the composition is from about 3 to about 9, for example from about 4 to about 6.

[00150] In some embodiments, the viscosity of the composition remains within a predetermined range within which the composition is suitable for application to a substrate for at least about 3, 5, 7, 8, 9, 10, 11, 12, 13, 14, 21, or 28 days.

[00151] In some embodiments, the adhesive comprises, consists of, or consists essentially of a macromolecular complex comprising:

[00152] (A) a first component comprising

[00153] (i) a structure element selected among

[00154] (a) a polypeptide,

[00155] (b) a polysaccharide or a saccharide conjugate comprising a polysaccharide and a first linker molecule, and

[00156] (c) a lignin or a lignin conjugate comprising a lignin and a second linker molecule; It is

[00157] (ii) a polyphenol comprising a tannin; It is

[00158] (B) a second component comprising a polypeptide.

[00159] In another aspect, the invention provides an adhesive precursor composition comprising, consisting of, or consisting essentially of a first component comprising:

[00160] (i) a structure element selected among

[00161] (a) a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof,

[00162] (b) a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof, or a saccharide conjugate comprising a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof and a first linker molecule, and

[00163] (c) a lignin, a lignan or a lignin conjugate comprising a lignin and a second linker molecule; It is

[00164] (ii) a polyphenol comprising a tannin, a tannic acid, a flavonoid, a polyresorcinol or any combination of any two or more thereof.

[00165] In one embodiment, structure element (a) is a polypeptide, an oligopeptide, an amino acid, or any combination of any two or more thereof.

[00166] In one embodiment, the first component, the structure element, and the polyphenol are as defined in any of the embodiments described herein.

[00167] In some embodiments, the precursor composition comprises a denaturing agent and/or one or more additives, for example, an organic solvent, a surfactant, a dispersant, a viscosity modifier, and/or a hydrophobizing agent, as may be present in the adhesive composition.

[00168] In one embodiment, the composition is in the form of solid particles or an aqueous solubilization, solution, dispersion or suspension.

[00169] In another aspect, the present invention provides a process for producing an aqueous adhesive composition comprising, consisting of, or consisting essentially of a macromolecular complex, the process comprising:

[00170] (1) provide an aqueous composition comprising a first component, the first component comprising:

[00171] (i) a structure element selected among

[00172] (a) a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof,

[00173] (b) a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof, or a saccharide conjugate comprising a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof and a first linker molecule,

[00174] (c) a lignin, a lignan or a lignin conjugate comprising a lignin and a second linker molecule; It is

[00175] (ii) a polyphenol comprising a tannin, a tannic acid, a flavonoid, a polyresorcinol or any combination of any two or more thereof; It is

[00176] (2) mixing a second component comprising a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof to form a macromolecular complex.

[00177] In one embodiment, the first component, the structure element, the polyphenol, and the second component are as defined in any of the embodiments described herein.

[00178] In some modalities, step (1) comprises:

[00179] (a) providing an aqueous composition comprising the structure element;

[00180] (b) mixing the polyphenol to form the first component.

[00181] In one embodiment, the process comprises:

[00182] (1)(a) provide an aqueous composition comprising a structural element selected from among

[00183] (a) a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof,

[00184] (b) a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof, or a saccharide conjugate comprising a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof and a first linker molecule,

[00185] (c) a lignin, a lignan or a lignin conjugate comprising a lignin and a second linker molecule; It is

[00186] (1)(b) mixing a polyphenol comprising a tannin, a tannic acid, a flavonoid, a polyresorcinol or any combination of any two or more thereof to form a first component; It is

[00187] (2) mixing a second component comprising a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof with the first component to form a macromolecular complex.

[00188] In another modality, the process comprises:

[00189] (1)(a) provide an aqueous composition comprising a structural element selected from among

[00190] (a) a polypeptide,

[00191] (b) a polysaccharide or a saccharide conjugate comprising a polysaccharide and a first linker molecule,

[00192] (c) a lignin or a lignin conjugate comprising a lignin and a second linker molecule; It is

[00193] (1)(b) mixing a polyphenol comprising a tannin to form a first component; It is

[00194] (2) (2) mixing a second component comprising a polypeptide with the first component to form a macromolecular complex.

[00195] In some arrangements, step (1)(a) comprises:

[00196] (i) providing an aqueous composition comprising (a) a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof, or (b) a first linker molecule; It is

[00197] (ii) mixing the other of (a) or (b) so as to form a saccharide conjugate; or

[00198] (i) providing an aqueous composition comprising (a) a lignin or (b) a second linker molecule; It is

[00199] (ii) mixing the other of (a) or (b) so as to form a lignin conjugate.

[00200] In some embodiments, the first linker molecule (b) or the second linker molecule (b) comprises two or more linker molecules, and step (1)(a) comprises mixing the two or more linker molecules with (a) in any order.

[00201] In some embodiments, the first linker molecule or the second linker molecule comprises two or more linker molecules, and step (1)(a) comprises mixing one of the two or more linker molecules with (a) to conjugate the linker molecule and (a), and then subsequently mixing one or more other linker molecules to form a saccharide conjugate or a lignin conjugate comprising a first linker molecule or a second linker molecule comprising two or more linker molecules adjacent to each other.

[00202] In some embodiments, the provision of step (1), (1)(a), or (1)(a)(i), or any combination of any two or more thereof, comprises solubilizing, dissolving, dispersing, or suspending the first component, the structural element, the polysaccharide, the oligosaccharide, the monosaccharide, or any combination of any two or more thereof, the first linker molecule, the lignin, or the second linker molecule in a aqueous solution.

[00203] In some embodiments, the aqueous composition of step (1), (1)(a), or (1)(a)(i), or any combination of any two or more thereof is a solubilization, a solution, a dispersion, or a suspension.

[00204] In some modalities, solubilization, solution, dispersion, or suspension is stable to precipitate the element of structure, polysaccharide, oligosaccharide, monosaccharide, or any combination of any two or more, the first library molecule, lignin, or second molecule for a period of at least 2, 5, 10, 15, 30, 30, 30, 30, 30 60 minutes.

[00205] In some embodiments, the solubilization, dissolution, dispersion, or suspension is carried out at alkaline pH or at elevated temperature or both.

[00206] In some embodiments, the mixing of step (2), (1)(b), or (1)(a)(ii), or any combination of any two or more thereof is performed at alkaline pH or at elevated temperature or both.

[00207] In some embodiments, the pH is at least about 8, at least about 9, or at least about 10.

[00208] In some embodiments, the pH is from about 8 to about 13, from about 8 to about 12, from about 8 to about 11, from about 8 to about 10, from about 8 to about 9, from about 9 to about 13, from about 9 to about 12, from about 9 to about 12 11, from about 9 to about 10, from about 10 to about 13, from about 10 to about 12, from about 10 to about 11, from about 11 to about 13, from about 11 to about 12.

[00209] In some embodiments, the temperature is at least about 50, at least about 55, at least about 60, at least about 65, or at least about 70°C.

[00210] In some embodiments, the temperature is from about 50 to about 95°C, from about 50 to about 90, from about 50 to about 80, from about 50 to about 70, from about 50 to about 60, from about 60 to about 95, from about 60 to about 90, to from about 60 to about 80, from about 60 to about 70, from about 70 to about 95, from about 70 to about 90, from about 70 to about 80, from about 80 to about 95, or from about 80 to about 90°C.

[00211] In some embodiments, the pH or the temperature or both the pH and the temperature of the aqueous composition are maintained during mixing.

[00212] In some embodiments, the mixing of step (2), (1)(b), or (1)(a)(ii), or any combination of any two or more thereof, comprises solubilizing, dissolving, suspending or dispersing the second component, the polyphenol, the polysaccharide, the oligosaccharide, the monosaccharide, or any combination of any two or more thereof, the first linker, the lignin, or the second linker.

[00213] In some embodiments, the mixing of step (2), (1)(b), or (1)(a)(ii), or any combination of any two or more thereof additionally comprises adjusting the conditions (i.e., one or more reaction conditions) so as to form the macromolecular complex, the first component, the saccharide conjugate, or the lignin conjugate.

[00214] In some embodiments, adjusting the conditions (that is, one or more reaction conditions) comprises reducing the pH or the temperature or both the pH and the temperature.

[00215] In some embodiments, the pH is reduced to a pH of at least about 8, at least about 9, or at least about 10.

[00216] In some embodiments, the temperature is reduced to a temperature from about 50 to about 80°C.

[00217] In some embodiments, the mixing of step (2), (1)(b), or (1)(a)(ii), or any combination of any two or more thereof, further comprises mixing the second additional component, the additional polyphenol, the additional polysaccharide, the additional oligosaccharide, the additional monosaccharide, or any combination of any two or more thereof, the first additional linker, the additional lignin, or the second additional linker.

[00218] In some embodiments, the mixture of step (2), (1)(b), or (1)(a)(ii), or any combination of any two or more thereof comprises:

[00219] (A) mixing the second component, the polyphenol, the polysaccharide, the oligosaccharide, the monosaccharide, or any combination of any two or more thereof, the first linker, the lignin, or the second linker;

[00220] (B) adjust the reaction conditions so as to form the macromolecular complex, a first component, a saccharide conjugate, or a lignin conjugate; It is

[00221] (C) mixing the second additional component, the additional polyphenol, the additional polysaccharide, the additional oligosaccharide, the additional monosaccharide, or any combination of any two or more thereof additional, the first additional linker, the additional lignin, or the second additional linker so as to form the macromolecular complex, the first additional component, the additional saccharide conjugate, or the additional lignin conjugate.

[00222] The additional macromolecular complex, the first additional component, the additional saccharide conjugate, or the additional lignin conjugate formed in step (C) may be the same or different from the macromolecular complex, the first component, the saccharide conjugate, or the lignin conjugate formed in step (B).

[00223] In some embodiments, the additional macromolecular complex, the first additional component, the additional saccharide conjugate, or the additional lignin conjugate formed in step (C) is formed from the macromolecular complex, the first component, the saccharide conjugate, or the lignin conjugate formed in step (B).

[00224] In some embodiments, the mixing of step (2), (1)(b), or (1)(a)(ii), or any combination of any two or more thereof, is performed under conditions that inhibit or prevent clotting in the reaction mixture.

[00225] In one embodiment, the composition comprises one or more selected additives that enhance the solubilization, dissolution, suspension, or dispersion of any one or more of the first component, the second component, the structure element, the first linker, the second linker, the polysaccharide, the oligosaccharide, the monosaccharide, or any combination of any two or more thereof, the lignin, or any combination of any two or more thereof.

[00226] In some embodiments, the additive is selected from the group consisting of organic solvents, surfactants, and dispersants.

[00227] In some embodiments, step (2) is performed at a pH of from about 8 to about 10. In example embodiments, step (2) is performed at a pH of about 9.

[00228] In some embodiments, the polypeptide, oligopeptide, amino acid, polyamine, or any combination of any two or more thereof in step (2) is mixed under conditions that inhibit or prevent clotting in the reaction mixture.

[00229] In some embodiments, the conditions are alkaline. In some embodiments, the pH is about 9. In some embodiments, the temperature is from about 50 to about 80°C. In some embodiments, the temperature is about 70°C.

[00230] In some embodiments, the polypeptide, oligopeptide, amino acid, polyamine, or any combination of any two or more is mixed in combination with or after mixing one or more additives that enhance its solubility. In some embodiments, the additive is a protein denaturing agent.

[00231] In some embodiments, step (1)(b) is performed at a pH from about 9 to about 13. In some embodiments, the pH is from about 9 to about 12. In some embodiments, the pH is from about 9 to 11.5. In some embodiments, the pH is from about 10 to about 11. In some embodiments, the pH is about 11. In some embodiments, the pH is about 9.

[00232] In some embodiments, step (1)(b) is performed at a temperature from about 70 to about 95°C. In some embodiments, the temperature is about 90°C. In some embodiments, the temperature is from about 50 to about 80°C. In some embodiments, the temperature is about 70°C.

[00233] In some embodiments, conditions are adjusted in order to form the macromolecular conjugate. In some embodiments, the pH is lowered. In some embodiments, the pH is reduced to about 9. In some embodiments, the temperature is reduced. In some embodiments, the temperature is reduced to from about 50 to about 80°C. In some embodiments, the temperature is reduced to about 70°C.

[00234] In some embodiments, step (1)(b) comprises:

[00235] (A) mix the polyphenol;

[00236] (B) adjust the reaction conditions to form a first component; It is

[00237] (C) Mix additional polyphenol to form the first component.

[00238] In some embodiments, the first component formed in step (C) is formed from the first component in step (B), for example by adding pendant tannin units.

[00239] In some embodiments, the additional polyphenol is mixed under conditions that inhibit or prevent clotting in the reaction mixture.

[00240] In some embodiments, the conditions are alkaline. In some embodiments, the pH is about 9. In some embodiments, the temperature is from about 50 to about 80°C. In some embodiments, the temperature is about 70°C.

[00241] In some embodiments, step (1)(a) comprises solubilizing, dissolving, dispersing, or suspending a structure element in an aqueous solution.

[00242] In some embodiments, the structure element is solubilized, dissolved, dispersed, or suspended under alkaline conditions. In some embodiments, the pH is from about 9 to about 13. In some embodiments, the pH is about 11.

[00243] In some embodiments, the structure element is solubilized, dissolved, dispersed, or suspended at an elevated temperature. In some embodiments, the structure element is solubilized, dissolved, dispersed, or suspended at a temperature of from about 70 to about 95°C. In some embodiments, the temperature is about 90°C.

[00244] In one embodiment, step (1)(a) comprises solubilizing, dissolving, dispersing, or suspending an element of structure (a) in an aqueous solution under alkaline conditions. In one embodiment, the pH is from about 10 to about 12. In another embodiment, the pH is about 10.5.

[00245] In one embodiment, step (1)(a) comprises solubilizing, dissolving, dispersing, or suspending an element of structure (a) in an aqueous solution at an elevated temperature. In one embodiment, the temperature is from about 50 to about 90°C. In another embodiment, the temperature is about 70°C.

[00246] In one embodiment, step (1)(a)(ii) comprises mixing the first linker molecule under alkaline conditions or at elevated temperature or both so as to form the saccharide conjugate. In one embodiment, the pH is about 9.

[00247] In one embodiment, the first linker is an inorganic polyhydroxy nonmetallic compound or an ester or salt thereof. In one embodiment, the polyhydroxylated non-metallic compound is boric acid or an ester or salt thereof.

[00248] In one embodiment, step (1)(a)(ii) comprises mixing the second linker molecule under alkaline conditions or elevated temperature or both, and adjusting the conditions so as to form the lignin conjugate.

[00249] In one embodiment, adjusting the conditions so as to form the lignin conjugate comprises reducing the pH. In one embodiment, the pH is reduced to about 9.

[00250] In one embodiment, adjusting the conditions so as to form the lignin conjugate comprises reducing the temperature. In one embodiment, the temperature is reduced to a temperature from about 50 to about 80°C. In another embodiment, the temperature is reduced to about 70°C.

[00251] In one embodiment, step (1)(a)(ii) comprises mixing the second linker molecule and an enzyme under conditions effective to enzymatically conjugate the second linker molecule to form the lignin conjugate.

[00252] In some embodiments, step (1)(a)(ii) comprises mixing an amine compound and an aldehyde to form the lignin conjugate.

[00253] In some embodiments, step (1)(a)(ii) comprises mixing a carboxylic acid compound or salt, ester, anhydride, or halide thereof and an inorganic polyhydroxy nonmetallic compound or ester or salt thereof to form the lignin conjugate.

[00254] In some embodiments, step (1)(a)(ii) comprises mixing a carboxylic acid compound or a salt, an ester, anhydride, or halide thereof and lignin to conjugate the carboxylic acid compound or a salt, ester, anhydride, or halide thereof to the lignin, and subsequently mixing a polyhydroxylated non-metallic compound, preferably boric acid or an ester or salt thereof, to form a lignin conjugate comprising an inorganic polyhydroxy non-metallic compound or ester or salt thereof and a carboxylic acid compound or salt, ester, anhydride or halide thereof adjacent thereto.

[00255] In one embodiment, the second linker molecule is an amine compound or a salt thereof. In one embodiment, the amine compound is lysine.

[00256] In one embodiment, step (1)(a)(ii) comprises mixing the lignin under alkaline conditions or at elevated temperature or both, and adjusting the conditions so as to form the lignin conjugate.

[00257] In one embodiment, the second linker is a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof. In one embodiment, the polysaccharide, oligosaccharide, monosaccharide, or any combination of any two or more thereof is zein.

[00258] In one embodiment, adjusting the conditions comprises reducing the pH. In one embodiment, the pH is reduced to about 9.

[00259] In one embodiment, adjusting the conditions comprises reducing the temperature. In one embodiment, the temperature is reduced to from about 50 to about 80°C. In another embodiment, the temperature is reduced to about 70°C.

[00260] In one embodiment, the lignin is mixed under alkaline conditions or at elevated temperature or both. In one embodiment, the pH is about 12.5.

[00261] In some embodiments, the second component is mixed in combination with or after mixing one or more additives that enhance the solubilization, dissolution, dispersion, or suspension of the second component.

[00262] In some embodiments, the additive is a protein denaturing agent as defined in any of the embodiments described herein.

[00263] In some embodiments, the additive is selected from sodium salts, for example sodium sulfite, and glycerol, or any combination of any two or more thereof. In some embodiments, the additive is sodium sulfite.

[00264] In some embodiments, step (2) comprises mixing the second component and a protein denaturing agent with the aqueous composition comprising the first component.

[00265] In some embodiments, the protein denaturing agent is mixed with the aqueous composition comprising the first component prior to or contemporaneously with the second component.

[00266] In some embodiments, step (2) comprises mixing a composition comprising the second component and a protein denaturing agent with the aqueous composition comprising the first component. In some embodiments, the composition comprising the second component and a protein denaturing agent is an aqueous solubilization, solution, dispersion, or suspension.

[00267] In some embodiments, the denaturing agent is as defined in any of the embodiments described above.

[00268] In some embodiments, step (2) additionally comprises mixing one or more viscosity modifying agents.

[00269] In some embodiments, step (2) additionally comprises mixing one or more dispersing agents.

[00270] In some embodiments, step (2) comprises mixing the second component at a first elevated temperature, optionally maintaining the first temperature for a first period of time, adjusting the temperature to a second temperature, and maintaining the second temperature for a second period of time.

[00271] In some embodiments, step (2) comprises mixing the second component at a first elevated temperature, optionally maintaining the first temperature for a first period of time until at least partially solubilizing, dissolving, or suspending or dispersing the second component, adjusting the temperature to a second temperature, and maintaining the second temperature until further solubilizing, dissolving, or suspending or dispersing the second component.

[00272] In some embodiments, the second temperature is lower than the first temperature.

[00273] In some embodiments, the optional step of maintaining the first temperature for a first period of time is performed.

[00274] In some embodiments, the method comprises after step (2), a step (3) comprising adjusting the pH of the composition, preferably to a pH within from about 3 to about 9, for example from about 4 to about 6.

[00275] In one embodiment, the ratio of structure element to polyphenol, structure element (a) to polyphenol, structure element (a) to polyphenol to second component, structure element (b) to polyphenol, structure element (c) to polyphenol, second component to polyphenol, polyphenol to first chainer molecule, polyphenol to second chainer molecule, lignin to second chainer molecule, linker nin to second linker molecule (a), lignin to second linker molecule (c), or second linker molecule (c) to lignin to polyphenol, or any combination of any two or more thereof as defined in any of the embodiments described herein.

[00276] In another aspect, the present invention provides an aqueous adhesive composition produced by means of a process according to the present invention.

[00277] In another aspect, the present invention provides a process for producing an adhesive precursor composition comprising, consisting of, or consisting essentially of a first component, the process comprising:

[00278] (1) provide an aqueous composition comprising a structure element selected from

[00279] (a) a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof,

[00280] (b) a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof, or a saccharide conjugate comprising a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof and a first linker molecule,

[00281] (c) a lignin, a lignan or a lignin conjugate comprising a lignin and a second linker molecule; It is

[00282] (2) mixing the framework element with a polyphenol comprising a tannin, a tannic acid, a flavonoid, a polyresorcinol or any combination of any two or more thereof to provide a first component.

[00283] In some embodiments, the element of structure (a) is a polypeptide, an oligopeptide, an amino acid, one or any combination of any two or more thereof.

[00284] In some embodiments, the frame element and the polyphenol are as defined in any of the embodiments described herein.

[00285] In another aspect, the present invention provides an adhesive precursor composition comprising, consisting of, or consisting essentially of a first component produced by means of a process according to the present invention.

[00286] In another aspect, the present invention provides a lignocellulosic substrate comprising a cured or curable adhesive composition of the present invention.

[00287] In some embodiments, the substrate is a lignocellulosic composite. In some embodiments, the composite comprises lignocellulosic fibers, particles, flakes, filaments, chips, or sheets. In some embodiments, the lignocellulosic fibers, particles, flakes, strands, chips, or sheets are wood fibers, particles, flakes, strands, chips, or sheets.

[00288] In some embodiments, the adhesive loading is from about 5% to about 50% by weight.

[00289] In some embodiments, the composite has:

[00290] (a) an internal bond strength of at least about 0.45 MPa when tested in accordance with AS/NZS:4266;

[00291] (b) a density of at least about 600 kg/m3 when assessed in accordance with AS/NZS:4266;

[00292] (c) an average maximum load value of at least about 1250 N when tested in accordance with ASTM D906-98;

[00293] (d) a tensile stress of at least about 2 MPa when tested in accordance with ASTM D906-98;

[00294] (e) a satisfactory chisel test glue line bond rating when tested in accordance with AS/NZS 2098.2:2006 B;

[00295] (f) formaldehyde emissions of less than 0.5 mg/L when tested in accordance with AS/NZS 4266:2004 after 7 days of conditioning; or

[00296] (g) any combination of any two or more thereof, for example three, four, five, or more.

[00297] In some embodiments, the internal bond strength is at least about 0.5, about 0.55, about 0.6, or about 0.65 MPa.

[00298] In some embodiments, the density is at least about 650, about 700, or about 750 kg/m3.

[00299] In some embodiments, formaldehyde emissions are less than about 0.45, about 0.4, about 0.35, or about 0.3 mg/L.

[00300] In some embodiments, the composite is particle board, oriented particle board, waferboard, fiberboard, parallel yarn lumber, laminated yarn lumber, plywood, laminated plywood, finger-jointed lumber, scrimber board, cardboard, linerboard, or other engineered wood product or engineered wood product board.

[00301] In some embodiments, the composite is particle board, oriented particle board, chipboard, fiberboard, parallel-ply lumber, laminated-ply lumber, plywood, laminated plywood, or finger-jointed lumber. In some embodiments, the composite is particleboard, fiberboard, or plywood.

[00302] In another aspect, the present invention provides a process for producing a lignocellulosic composite, the process comprising applying the adhesive composition of the present invention to lignocellulosic fibers, particles, flakes, filaments, chips, or sheets; and forming a composite of the fibers, particles, flakes, filaments, flakes or sheets.

[00303] In some embodiments, the formation of the composite comprises the application of heat or pressure or both.

[00304] In some embodiments, the heat applied is from a temperature of from about 120 to about 250°C. In some embodiments, the temperature is from about 150 to about 220°C.

[00305] In some embodiments, the pressure is from about 5 kN to about 35 kN.

[00306] In another aspect, the present invention provides a process for bonding a first substrate to a second substrate, the process comprising:

[00307] (a) applying the adhesive composition of the present invention to the first substrate or to the first substrate and the second substrate; It is

[00308] (b) contacting the second substrate or the adhesive applied to the second substrate with the adhesive applied to the first substrate to bond the first substrate to the second substrate.

[00309] In another aspect the present invention provides an adhesive for lignocellulosic substrates and particularly for the manufacture of lignocellulosic composites and for joining wood, which comprises the reaction product of:

[00310] (a) a first component being itself the product of the reaction of

[00311] (i) a structure element; It is

[00312] (ii) a polyphenolic bioderivative such as tannin, a tannin-rich material or a combination of polyphenolic lignin and tannin;

[00313] and

[00314] (b) (b) a second component comprising a protein or a substrate rich in protein or amino acid;

[00315] wherein the structure element consists of one or more of zein, a material or residue from corn or corn grain rich in zein, wheat gluten, soy protein, soy flour or soy bran, any other protein, lignin, a lignin derivative such as a lignosulphonate, a lignin-amine compound conjugate, a zein and lignin conjugate, starch, amino sugars including chitosan, chitin, or conjugates of sugar and protein.

[00316] Preferably the protein or protein rich substrate is soy protein, soy flour or soy bran or any other bio-derived protein or high protein raw material including but not limited to keratin, gluten and casein.

[00317] Preferably the structure element is subjected to alkaline solubilization and the tannin is added to the structure element in solution and the pH is adjusted to approximately pH 9 in order to promote the formation of the first component.

[00318] Preferably the protein or protein-rich substrate is added to the first component while still in solution while maintaining the pH at pH 9 or about pH 9.

[00319] Preferably the protein-rich substrate is one or more of soy protein, soy flour, wheat gluten or other proteinaceous material.

[00320] Preferably a denaturing agent is added with the protein or with the protein-rich substrate.

[00321] The denaturing agent may consist of glycerol, sodium salts such as sodium chloride or sodium sulfite or sodium bisulfite (hydrogen sulfite), urea, thiols, surfactants and dispersants or any combination of any two or more thereof.

[00322] Preferably, the component structure element is initially solubilized at a pH of 9 to 11.5 and at temperatures of 50 to 90°C.

[00323] Preferably during solubilization of zein a pH of about pH 11 or more is used and preferably a pH greater than pH 10.2 for lignin.

[00324] Preferably after solubilization of the structure element the tannin is added, dispersed and the pH is reduced to 9 in order to induce the formation of the first component.

[00325] Preferably when the polyphenolic bioderivative is a combination of lignin and tannin, the lignin and tannin are added sequentially.

[00326] Optionally boric acid is added when impure raw materials are used to promote binding of starch and carbohydrate and other impurities.

[00327] Optionally, an additional viscosity modifier is added.

[00328] Optionally a wax or a wax-based additive is also added.

[00329] Preferably the additional viscosity modifier is selected from sodium sulfite or sodium bisulfite. It will be apparent to a person skilled in the art that a range of other viscosity modifiers can be used.

[00330] Preferably zein-rich material or residue from maize or maize grain means a material or residue that has at least 30% zein by dry weight.

[00331] Preferably the protein content of the zein or zein-rich ingredient is at least 50% and more preferably at least 60% by weight.

[00332] In some embodiments of the invention the structural element is first formulated by adding lignin to zein, or an amino acid such as lysine to lignin.

[00333] In an embodiment of the invention in which lignin is used, before adding tannin, an amino acid is added.

[00334] Preferably the amino acid has 2 or more amino groups.

[00335] The preferred amino acid is lysine.

[00336] Where a lignin-lysine combination is used, the conjugation of the lignin with the lysine can be carried out in more than one way. For example, it can be performed through pH adjustment and resuspension. It can also be performed by grafting covalent bonds promoted by an enzyme such as laccase.

[00337] In one embodiment of the invention glycerol or sodium salts are added to the first component in solution with or before addition of the protein or protein-rich substrate. Said additives may aid in the dissolution of the soy protein and may have an effect on the viscosity of the final formulation.

[00338] In another aspect, the present invention provides a process for manufacturing an adhesive or a resin comprising:

[00339] - solubilization of a structure element;

[00340] - addition and dispersion of a polyphenolic bioderivative such as tannin, a tannin-rich material or a combination of polyphenolic lignin and tannin under conditions that prevent the structure element from coagulating before the tannin is dispersed;

[00341] - change of conditions in order to induce the formation of a first component of the structure element and the polyphenolic bioderivative;

[00342] - optionally addition of more polyphenolic bioderivative; It is

[00343] - addition of a second component comprising a protein or material rich in protein or amino acid under conditions and/or with additives that stimulate the solubilization and denaturation of the protein or material rich in protein or amino acid without inducing coagulation or precipitation or impairing the intermediate conjugate.

[00344] In another aspect the present invention provides the use of the adhesive of the present invention in an adhesive mixture, for example with another resin such as a UF, phenolic, melamine, polyamine, or isocyanate resin, or other amino resin, in which the adhesive not only provides its own adhesive effect but also functions as a formaldehyde extractor reducing formaldehyde emissions while the lignocellulosic composite is in synthesis or in use.

[00345] In another aspect the present invention provides an adhesive blend comprising an adhesive composition of the present invention and one or more additional adhesives.

[00346] In another aspect the present invention provides an adhesive blend comprising an adhesive precursor composition of the present invention and one or more additional adhesives.

[00347] In another aspect the present invention provides a process for producing an adhesive mixture comprising mixing an adhesive composition of the present invention and one or more additional adhesives.

[00348] In another aspect the present invention provides a process for producing an adhesive mixture comprising mixing an adhesive precursor composition of the present invention and one or more additional adhesives.

[00349] In some embodiments, the one or more additional adhesives in the above aspects comprise UF, phenolic, melamine, polyamine, or isocyanate resin, or other amino resin.

[00350] In a further aspect the present invention provides use of the adhesive of the present invention together with or in a mixture with other soy-based adhesives that use isocyanate, epichlorohydrin or polyamidoamine. In some embodiments, use of the present adhesive minimizes the need for petrochemical crosslinkers.

[00351] In a further aspect the present invention provides a lignocellulosic material-adhesive composite such as mdf panels, particle board, plywood and similar products incorporating a lignocellulosic material and the adhesive system as described herein.

[00352] The term "comprising" as used in this specification and the claims means "consisting at least in part of". By interpreting each statement in this descriptive report and in the claims that includes the term "comprising", it means that others besides the one or those preceded by the term may also be present. Related terms such as "comprises" and "comprises" are to be interpreted in the same way.

[00353] As used herein, the term "and/or" means "and" or "or", or both.

[00354] As used herein, "(s)" after a noun means the plural and/or singular forms of the noun.

[00355] Reference to a range of numbers disclosed herein, (for example, 1 to 10) is intended to also incorporate reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7), and therefore all subtracks of all tracks expressly disclosed herein, are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numeric values between the lowest and highest values listed are to be deemed to be expressly stated in this application in a similar manner.

[00356] In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for the discussion of the features of the invention. Unless specifically stated otherwise, reference to similar external documents is not to be construed as an admission that said documents, or said sources of information, in any jurisdiction, are prior art, or form part of common general knowledge in the art.

[00357] To those skilled in the art to which the invention relates, many modifications in the construction and modalities and applications of the invention widely differing will be suggested without departing from the scope of the invention as defined in the appended claims. The disclosures and descriptions herein are purely illustrative and are not intended to be limiting in any way.

[00358] While the present invention is broadly as defined above, those skilled in the art will recognize that the invention is not limited thereto and that the invention also includes embodiments of which the following description provides examples.

DETAILED DESCRIPTION OF THE INVENTION

[00359] The adhesive composition of the present invention comprises a macromolecular complex comprising a first component and a second component associated with each other. Components can be associated with each other in the macromolecular complex by covalent bonds or non-covalent bridging interactions, for example, ionic bonding, hydrogen bonding, van der Walls forces, π-stacking interactions, or hydrophobic interactions.

[00360] The first component comprises a structural element and an associated polyphenol. As for the first component and the second component in the macromolecular complex, the structural element and the polyphenol of the first component can be associated by covalent or non-covalent bridge interactions.

[00361] The term "complex" and related terms such as "complexes" and the like are used herein to designate an association of two or more molecules, including macromolecules, either by chemical attraction or physical attraction. For example, an association of a first component and a second component, or an association of a structure element and a polyphenol. Therefore the complexes described here are not limited to coordination complexes comprising for example a metal or a metal ion coordinated by one or more ligands.

[00362] The macromolecular complex comprises a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof. In some embodiments, the polypeptide or oligopeptide is a zein, soy, keratin, gluten, casein, or whey polypeptide or oligopeptide, or any combination of any two or more thereof.

[00363] The polypeptide, oligopeptide, amino acid, or polyamine used may be obtained from any suitable source. In some embodiments, the polypeptide, oligopeptide, amino acid, or polyamine is isolated or purified polypeptide, oligopeptide, amino acid, or polyamine.

[00364] The polypeptide may be a protein, for example a meat, fish, dairy, egg, or plant protein. In some embodiments, the protein is a zein or soy protein.

[00365] Polypeptides include natural and synthetic proteins, for example, structural proteins, enzymes, and binding proteins.

[00366] Non-limiting examples of proteins include milk, whey, casein, egg, white, yolk, meat, beef, lamb, fish, seafood, silk, vegetable, legume, alfalfa, clover, pea, bean, bean, soy, lentil, lupine, mesquite, carob, walnut, peanut, rye, cereal, whole wheat, rice, hemp, wheat gluten, fungal, a lga, and any combination of any two or more thereof. Any similar protein can be unhydrolyzed, partially hydrolyzed, or completely hydrolyzed.

[00367] The polypeptide or oligopeptide may comprise one or more saccharides. In some embodiments, the polypeptide is a glycoprotein.

[00368] Suitable amino acids include natural and unnatural amino acids. As used herein, an "unnatural amino acid" refers to any amino acid, modified amino acid, or amino acid analog other than the following twenty genetically encoded a-amino acids: alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyres ina, and valine. Unnatural amino acids include, but are not limited to, N-substituted α-amino acids; α,α-di-substituted amino acids, including cyclic quaternary amino acids; D-amino acids; e-amino acids, including β2- and β3- amino acids and β2-2, β2-3-, β3,3-disubstituted amino acids, including cyclic variants; 3- to 9-membered ring proline analogues; Y-amino acids; and homo amino acids.

[00369] In some embodiments, the amino acid is a naturally occurring amino acid.

[00370] Polyamines are compounds characterized by the presence of two or more amine groups. Examples include alkanes having 2 or more carbons per chain such as 1,2-diaminoethane and 1,6-hexadiamine and compounds having ring structures such as 1,4-cyclohexane-diamine and 1,3-phenyldiamine.

[00371] Useful polyamines include linear or predominantly linear polyamines comprising 3, 4 or 5 or more amine groups.

[00372] Polyamines include monomeric compounds comprising two or more amine groups and furthermore polymers comprising said monomers.

[00373] In other embodiments, the framework element comprises a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof.

[00374] The polysaccharide, oligosaccharide, or monosaccharide may be obtained from any suitable source. In some embodiments, the polysaccharide, oligosaccharide, or monosaccharide is an isolated or purified polysaccharide, oligosaccharide, or monosaccharide.

[00375] The polysaccharide may be a natural polysaccharide or a modified polysaccharide. Natural polysaccharides include animal, plant, or microbial polysaccharides.

[00376] As used herein, the term "polysaccharide" refers to polymers comprising a backbone consisting essentially (e.g., at least about 80, 85, or 90%) of monosaccharide repeating units and/or modified monosaccharide repeating units.

[00377] In some embodiments, the polysaccharide is selected from the group consisting of starches, oxidized starches, hydrolyzed starches, gums, celluloses, hemicelluloses, dextrins, dextrans, glycogens, chitosans, chitins, aminopolysaccharides, glycoproteins, and any combination of any two or more thereof. In some embodiments, the polysaccharide comprises one or more reducing sugars.

[00378] Non-limiting examples of polysaccharides include starches, modified starches, amylopectin, modified amylopectin, amylose, modified amylose, chitosan, chitin, guar gum, modified guar gum, locust bean gum, tara gum, konjac gum, konjac flour, fenugreek gum, mesquite gum, aloe mannans, cellulose, modified cellulose such as carboxyalkylated cellulose and carboxymethyl cellulose, oxidized polysaccharides, sulfated polysaccharides, cationic polysaccharides, pectin, gum arabic, karaya gum, xanthan, kappa, iota or lambda carrageenans, agar-agar and alginates.

[00379] Polysaccharide starches include natural starches, chemically modified starches, and mixtures of one or more natural and/or chemically modified starches. Natural starches include corn starch, corn kernels, waxy corn, potato, cassava, tapioca, wheat starch, rice, waxy rice, peas, sago, oats, barley, rye, amaranth, and sweet potato. Chemically modified starches include, for example, carboxymethyl starch, hydroxyethyl starch, hydroxypropyl starch, acetate starch, sulfamate starch, phosphate starch, nitrogen modified starch, and the like, for example, chitosan and chitin.

[00380] Modified polysaccharides include polysaccharides modified, for example, by etherification, esterification, oxidation, acid hydrolysis, dextrinization, crosslinking, pregelatinization, or enzymatic treatment (for example with alpha-amylase, beta-amylase, pullulanase, isoamylase, or glucoamylase).

[00381] Non-limiting examples of modified polysaccharides include esters such as acetate and half-esters of dicarboxylic acids; ethers, such as hydroxyethyl and hydroxypropyl starches and starches reacted with hydrophobic cationic epoxides; starches oxidized with hypochlorite; starches reacted with cross-linking agents such as boric acid, phosphorus oxychloride, epichlorohydrin or phosphate derivatives prepared by reaction with sodium or potassium orthophosphate or tripolyphosphate. These and other conventional starch modifications are well known in the art.

[00382] Modified polysaccharides comprise a randomly substituted monosaccharide backbone with one or more modification groups.

[00383] Modifying groups include groups that mask or protect functional groups, for example hydroxyl groups such as ethers and esters, and groups that introduce additional functional groups, for example cationic, anionic, amphoteric, nonionic, and cross-linking groups, such as carboxylic acid, carboxylate, amino, and amido groups.

[00384] The modification groups can change the chemical and/or physical properties of the polysaccharide. For example, a modifying group can increase hydrophobicity, reduce hydrophilicity, or increase the ability to complex or otherwise associate with the polyphenol and/or other components of the macromolecular complex.

[00385] Modifications are not limited to those that provide properties that are beneficial in the context of the invention, but may include modifications that have a neutral or possibly harmful effect, for example on processing parameters with respect to the process by which the adhesive is prepared or on the immediate or long-term properties of the adhesive.

[00386] For example, a modified polysaccharide in which a small percentage of the hydroxyl groups present are masked, for example as acetyl or methoxy groups which are harmful in that they block binding or complexing sites, is still likely to be useful in the invention, since modifying only a small percentage of the functional groups of the polysaccharide is likely to have a minimal sum effect on the macromolecule and is therefore unlikely to make the modified polysaccharide incompatible with the process of formulation or significantly decrease the final bond strength of the adhesive in most cases.

[00387] Conversely, polysaccharides modified with groups that are beneficial in some embodiments, for example groups that can increase binding or complexation strength, such as carboxymethylation, carboxylation and hydroxyalkylation, in particular applications and/or at higher degrees of substitution, for example, can result in adhesives that are susceptible to moisture and can lead to moisture ingress and degradation of adhesive properties in engineered wood product comprising the aforementioned adhesives over time.

[00388] In some embodiments, the framework element comprises a saccharide conjugate comprising a polysaccharide, an oligosaccharide, or a monosaccharide, and a first linker molecule covalently or non-covalently conjugated thereto. Without wishing to be bound by theory, it is believed that in the macromolecular complex the first linker molecule acts as a linker (or moiety) through which the polysaccharide, oligosaccharide, or monosaccharide and the polyphenol can be associated.

[00389] The saccharide conjugate may comprise a plurality of first linker molecules, which may be the same or different.

[00390] The saccharide conjugate can be formed or obtained, or is obtainable, by conjugating a polysaccharide, an oligosaccharide, or a monosaccharide and a first linker molecule. A wide range of chainers can be suitable for conjugation.

[00391] The first linker molecule may comprise two or more linker molecules. In said embodiments, the saccharide conjugate can be formed or obtained, or is obtainable, by conjugating the polysaccharide, oligosaccharide, or monosaccharide and the two or more linker molecules simultaneously, or separately, or sequentially in any order.

[00392] In some embodiments the first linker molecule comprises two or more linker molecules adjacent to each other, which may be the same or different. Conjugates comprising the first named linker molecules can be prepared by conjugating the two or more linker molecules to the polysaccharide, oligosaccharide, or monosaccharide separately or sequentially.

[00393] In some embodiments, the second linker molecule capable of forming covalent bonds and/or non-covalent bridge interactions with the polyphenol and/or other components of the macromolecular complex. A saccharide conjugate may have a greater ability to form said bonds and/or bridging interactions compared to the polysaccharide, oligosaccharide, or monosaccharide from which it is formed.

[00394] In one embodiment, the first linker molecule may be an inorganic polyhydroxy nonmetallic compound or an ester or salt thereof, such as boric acid. Boric acid can be covalently conjugated to the polysaccharide, oligosaccharide, or monosaccharide by exchanging the hydroxyl groups present in the boric acid molecule with oxygen atoms of hydroxyl groups of the polysaccharide, oligosaccharide, or monosaccharide. In the foregoing embodiments, boric acid may be present in the conjugate as a boron ester of the polysaccharide, oligosaccharide, or monosaccharide.

[00395] Therefore, it will be recognized that conjugation of a linker molecule (e.g. a first linker molecule or a second linker molecule, or any one of two or more linker molecules into a first linker molecule or a second linker molecule comprising two or more linker molecules) by one or more covalent bonds can alter or modify the structure of the linker molecule.

[00396] In another embodiment, the first linker molecule is a metal ion. Saccharide conjugates comprising a metal ion as a linker molecule can be formed by treating the polysaccharide, oligosaccharide, or monosaccharide with a metal salt comprising the metal ion (i.e., the metal ion is provided in a suitable salt form). The metal ion may form a metal coordination complex with one or more oxygen atoms of hydroxyl groups present in the polysaccharide, oligosaccharide, or monosaccharide, preferably a chelating complex with two or more oxygen atoms of hydroxyl groups of the polysaccharide, oligosaccharide, or monosaccharide.

[00397] In some embodiments, the framework element comprises a lignin, a lignan or a lignin conjugate comprising a lignin and a second linker molecule.

[00398] The lignin can be isolated or purified lignin. Lignin can be obtained from various industrial processes.

[00399] Lignins are a heterogeneous group of polyphenolic compounds derived from secondary cell walls of plants and generally wood. The lignin in wood serves to crosslink polysaccharides in the cell wall and therefore impart mechanical strength to the cell wall and the plant itself as well as having a role in conducting water through vascular tissues.

[00400] Lignin comprises a variety of functional groups, for example, hydroxyl, methoxy, carbonyl and carboxyl groups. Phenolic hydroxy groups can be the most reactive. The number and range of functional groups make an enormous number of modifications of lignin possible, without removing its ability to conjugate with the polyphenol and with the second component in the macromolecular complex and without negating its structural and bonding function in the adhesive.

[00401] Lignin is a three-dimensional, complex and amorphous polymer, which has a structure based on phenylpropane. In its natural unprocessed form, the molecular structure of lignin varies according to source and is so complex and varied that its molecular structure has never been fully described.

[00402] Lignin is composed essentially of monolignols, a phenylpropanoid subgroup with a single propanoid side chain and phenyl hydroxyl groups.

[00403] There are three common monolignols that make up almost all lignin found in nature - p-coumaryl alcohol, coniferyl alcohol, and sinapyl alcohol (Scheme 1). These monomers are biosynthesized in plants via the shikimic acid pathway. Scheme 1.

[00404] The proportions of the various monomers depend on the species. p-Coumaryl alcohol is a component of forage and grass-type lignin but is rare in wood. Coniferyl alcohol is the predominant lignin monomer found in softwoods and both coniferyl alcohol and sinapyl alcohol are the main building blocks of hardwood lignin.

[00405] A variety of industrial isolation methods have been used to extract lignin from the source material. Lignins produced after isolation include lignin sulfonates, Kraft lignins, soda lignins, organosolve lignins, steam explosion lignins, softwood lignin, hardwood lignin, cellulosic grass lignins, corn straw lignins, and other lignins, all of which can be modified to produce modified lignins.

[00406] Lignins can be modified, for example, in the context of the present invention to improve structural properties, stability, etc. or to increase solubility, etc. Modified lignins are well known in the art.

[00407] Non-limiting examples of lignins and modified lignins include sulfinated and sulfonated lignin, lignin modified by hydroxymethylation, epoxidation, denitrication, acylation, or hydroxylation, lignin modified with diethanolamine, enzymatically modified lignin, lignin modified with Lacase, Kraft lignin, lignin modified with urea, lignosulfonates, Alcell lignins, granit alkali lignins, reflux lignins, lignin polyols (e.g. through propylene oxide modification), lignin modified by the addition of moieties such as antimicrobial compounds (e.g. paraben, terpenols, etc.), lignophenol, amino derivatives of lignin, lignins comprising complexed metal ions, and the like, e.g., demethylated lignin.

[00408] Native lignins are known to include carboxyl groups. Lignin can be modified to introduce additional carboxyl groups by oxidation (eg using sodium chlorite). Carboxyl-modified lignins are known and commercially available.

[00409] A wide range of modified lignins are useful in the present invention. Suitable lignins and modified lignins are capable of associating with one or more other components of the first component and/or the macromolecular complex to form the first component and/or the macromolecular complex. Modification that blocks all or the vast majority of complexing sites on a lignin (as can occur if a lignin is fully acetylated) can affect the ability of the concerned lignins to form the first component and/or the macromolecular complex.

[00410] Modified lignins comprise a randomly substituted lignin backbone with one or more modification groups. In some embodiments, lignin backbone phenolic hydroxyl groups are replaced with modifying groups.

[00411] The lignin backbone includes the carbon skeleton of the lignin polymer which can be derived from the carbons in the lignin monomer units. The lignin backbone additionally includes the ether linkages between the carbons of adjacent monomeric units, which can link the monomeric units together in the polymer backbone.

[00412] Modifying groups include groups that mask or protect functional groups, for example hydroxyl groups such as ethers and esters, and groups that introduce additional functional groups, for example cationic, anionic, amphoteric, nonionic, and crosslinking groups, such as carboxylic acid, carboxylate, amino, and amido groups.

[00413] Modification groups can change the chemical and/or physical properties of lignin. For example, a modifying group can increase hydrophobicity, reduce hydrophilicity, or increase the ability to complex or otherwise associate with the polyphenol and/or other components of the macromolecular complex.

[00414] In some embodiments, the lignin comprises a single monolignol as a lignin subunit. In some embodiments, the lignin subunit comprises from about 1 to about 20, from about 2 to about 20, or from about 5 to about 20 monolignol monomers. In some embodiments, the lignin comprises from about 1 to about 20, from about 2 to about 20, or from about 5 to about 20 monolignol monomers.

[00415] Lignans are plant polyphenols derived from lignin-like structural units. Lignans have structures in which two phenylpropanoid molecules having the C6-C3 backbone are dimerized. those with an 8,8' bond are the most prevalent class of lignans.

[00416] They can be found in different parts (roots, leaves, stems, seeds, fruits). In many sources (seeds, fruits), lignans are found as glycosidic conjugates associated with the fibrous component of plants. Examples of plant lignans include, but are not limited to: (+)-pinoresinol, (+)-sesamin, (+)-sesaminol, (+)-sesamolin and (+)-sesamolinol contained in sesame (Sesamum indicum); (+)-pinoresinol, (-)-arctigenin and (-)-matairesinol contained in forsythia (Forsythia intermedia); (-)-pinoresinol and (-)-lariciresinol contained in Daphne tangutica; (+)-secoisolaricyrresinol contained in linum (Linum usitatissimum), etc.

[00417] The lignin conjugate comprises a lignin and a second linker molecule covalently or non-covalently linked thereto. Without wishing to be bound by theory, it is believed that in the macromolecular complex the second linker molecule acts as a linker (or moiety) through which the lignin and the polyphenol can be associated.

[00418] The lignin conjugate may comprise a plurality of second linker molecules, which may be the same or different.

[00419] The conjugate can be formed or obtained, or is obtainable, by conjugating a lignin and a second linker molecule. A wide range of chainers can be suitable for conjugation.

[00420] In some embodiments, the second linker molecule capable of forming covalent bonds and/or non-covalent bridge interactions with the polyphenol and/or other components of the macromolecular complex. A lignin conjugate may have an increased ability to form said bonds and/or bridging interactions compared to the lignin from which it is formed.

[00421] In one embodiment, the second linker molecule can be a polypeptide, such as a zein protein. The zein protein is covalently or non-covalently attached by one or more functional groups present on the zein protein to lignin.

[00422] In another embodiment, the second linker molecule can be an amine compound, such as the amino acid lysine. Lysine can be covalently grafted to lignin, for example, enzymatically or non-enzymatically as described herein.

[00423] In another embodiment, the second linker molecule is an aldehyde, for example, formaldehyde or glyoxal. Nucleophilic functional groups on the lignin can react with the carbonyl aldehyde groups in order to covalently conjugate the aldehyde to the lignin, for example, as an acetal or hemiacetal.

[00424] The second linker molecule may comprise two or more linker molecules. In said embodiments, the lignin conjugate can be formed or obtained, or is obtainable, by conjugating the lignin and the two or more linker molecules simultaneously, or separately, or sequentially in any order.

[00425] In some embodiments the second linker molecule comprises two or more separately linker molecules, which may be the same or different. Conjugates comprising said second linker molecules can be prepared by conjugating the two or more linker molecules to lignin separately or sequentially.

[00426] In some embodiments, the second linker molecule comprises an amine compound (a primary or secondary amine) and an aldehyde compound, such as formaldehyde and lysine. The reaction of formaldehyde and an amine compound with a lignin leads to covalent conjugation of the linkers to the lignin through Mannich-type reactions. It will be appreciated that in the foregoing embodiments formaldehyde may be incorporated into the conjugate in the form of a methylene group (-CH 2 -) linkage to the nitrogen atom of the amine group of the amine compound and another nucleophile, possibly of lignin.

[00427] In other embodiments, the second linker molecule comprises a carboxylic acid compound or a salt, an ester, an anhydride or a halide thereof, for example a dicarboxylic acid, and an inorganic polyhydroxylated non-metallic compound or an ester or a salt thereof, for example boric acid. In some embodiments, the dicarboxylic acid can be conjugated to the lignin, followed by the boric acid to provide a conjugate in which the dicarboxylic acid and the boric acid are contiguous with each other. In the foregoing embodiments, the dicarboxylic acid may be covalently attached to the lignin by one of the carboxylic acid groups while the other carboxylic acid group is covalently attached to the boric acid molecule.

[00428] In some embodiments, the polyphenol of the first component comprises a tannin, a tannic acid, a flavonoid, a polyresorcinol, or any combination of any two or more thereof.

[00429] The tannin, tannic acid, flavonoid, or polyresorcinol can be obtained from any suitable source. In some embodiments, the tannin, tannic acid, flavonoid, or polyresorcinol is an isolated or purified tannin, tannic acid, flavonoid, or polyresorcinol.

[00430] Tannins are a group of plant polyphenolic compounds present in a wide range of plants including woody trees but also in fruits, leaves and seeds such as grapes, persimmons, berries, cloves, vegetables, herbs, tea leaves and cocoa beans. Tannin molecules usually include numerous hydroxyl groups and often also carboxyl groups, and tend to form strong complexes and conjugates with a range of macromolecules.

[00431] Tannins include oligomeric polyphenols that occur naturally in a variety of plants. Isolated tannins typically form a heterogeneous mixture of tannin compounds.

[00432] Tannin compounds can be subdivided into two groups: condensed tannins, also known as proanthocyanidins, and hydrolysable tannins. Tannin oligomers typically occur as dimers, trimers, tetramers, pentamers, hexamers, heptamers, octamers, nonamers, or decamers. Oligomers with more than ten monomer segments can also be isolated, such as oligomers that include up to 50 units.

[00433] Tannin polymers and oligomers are essentially composed of the following base units: gallic acid, flavanols, and phloroglucinol. Which base unit(s) are present and their proportions are largely dependent on which plant the tannin is taken from.

[00434] Hydrolyzable tannins include ellagic and gallic acid esters of polyol core moieties such as sugars. Proanthocyanidins are polymers of flavanols (eg flavan-3-ols).

[00435] Tannins include tannic acid, proanthocyanidins, flavanoids, gallic acid esters, catechins, etc.

[00436] Tannins can be modified, for example, in the context of the present invention to improve structural properties, stability, etc. or to increase solubility, etc. Modified tannins are common knowledge in the art. Tannins can be modified, for example, as a result of their extraction process or the primary processing of the material from which the tannin is derived.

[00437] Modified tannins comprise a tannin backbone randomly substituted with one or more modification groups. In some embodiments, tannin backbone phenolic hydroxyl groups are replaced with modifying groups.

[00438] Modifying groups include groups that mask or protect functional groups, for example hydroxyl groups such as ethers and esters, and groups that introduce additional functional groups, for example cationic, anionic, amphoteric, non-ionic, and crosslinking groups, such as carboxylic acid, carboxylate, amino, and amido groups.

[00439] Examples of tannins and modified tannins include, but are not limited to, sulphited tannins, lignin-tannin complexes, tannates (e.g. tannic acid salts or esters), tannin salts, etherified tannins, alkylated (e.g., methylated) tannins, tannin esters (e.g., acetylated tannins), tannin metal complexes (e.g., copper tannins), amine-modified tannins, and the like , for example cationic or anionic tannins, and hydroxypropylated tannins. A wide range of modified tannins are useful in the present invention. Suitable tannins and modified tannins are capable of associating with one or more other components of the first component and/or the macromolecular complex to form the first component and/or the macromolecular complex. Modification that blocks all or the vast majority of complexing sites on a tannin, for example acetylation of substantially all of the hydroxyl groups on a tannin, can affect the ability of the tannins concerned to form the first component and/or the macromolecular complex.

[00440] For tannins to act as protein binders/crosslinkers, they generally must be of a certain size and have sufficient binding sites. In general, the tannins are very high, so this is not a problem. In some embodiments, the tannin subunits may also be large enough and have sufficient binding sites to be useful in the invention.

[00441] In some embodiments, the tannin comprises 4 or more phenyl groups and 10 or more hydroxyl groups. In some embodiments, the tannin is a tannin subunit or a modified tannin comprising 4 or more phenyl groups and 10 or more hydroxyl groups.

[00442] Flavonoids, including polyflavonoids, are a generally known class of secondary plant metabolites which are ubiquitous in leaves, stems, and bark of plants and trees. This broad class of compounds commonly referred to as tannins includes hydrolysable and condensed tannins which are distinguished by their polyphenolic compositions of either gallic acid or catechin-based monomer units.

[00443] Polyresorcinols are a class of polyphenolics typically extracted from marine sources such as seaweed. Polyresorcinols are structurally closely related to phloroglucinolic-based condensed tannins.

[00444] In order to provide the required functionality, such as bonding, crosslinking, durability and moisture tolerance, a combination of multiple components is required for an adhesive system.

[00445] The macromolecular complex in the adhesive composition of the present invention comprises a similar combination of components.

[00446] The various components can be combined in a specific order so as to form the macromolecular complex.

[00447] Those skilled in the art will recognize that in preparing the macromolecular complex (or the first component, the saccharide conjugate or the lignin conjugate) that the degree of incorporation of any given component into the macromolecular complex (or the first component, the saccharide conjugate or the lignin conjugate) may be less than 100%. In some embodiments, the degree of incorporation is from about 10% to about 99%, from about 10% to about 95%, from about 10% to about 90%, from about 10% to about 85%, or from about 10% to about 80% by dry weight of starting material (actual component) provided.

[00448] The formation of the macromolecular complex, the first component, the saccharide conjugate or the lignin conjugate can be determined by any suitable method, for example by nuclear magnetic resonance (NMR) spectroscopy or infrared spectroscopy as described herein. Formation can also be determined by precipitation or coagulation under conditions where the starting materials would conveniently be soluble, dispersed or suspended.

[00449] In some embodiments, the adhesive composition of the present invention can be produced by combining a protein or lignin (or other macromolecule that can serve a similar purpose, for example a polysaccharide) with a tannin in a first component (or, in the context of the adhesive, an intermediate that will be a copolymer in the cured adhesive) and subsequently combining the first component with a second component comprising a protein or protein-rich substrate. On curing, the first component and the protein in the second component crosslink to form a thermosetting or coldsetting adhesive or resin.

[00450] When combined with a lignocellulosic material such as wood fiber or plywood, the adhesive components after curing also crosslink with the lignocellulosic material to form a composite material. The adhesive may be suitable for use in a range of engineered wood product composite materials. In some embodiments, better adhesive properties can be obtained when a denaturing agent is added with the protein or protein-rich substrate. Denaturing agents such as glycerol, sodium salts such as sodium chloride or sodium sulfite or sodium bisulfite (hydrogen sulfite), urea, thiols, surfactants and dispersants serve to open up protein molecules, destroying their quaternary, tertiary, and/or secondary structure, and can also help to solubilize them.

[00451] The adhesive of the present invention can be provided by component construction in stages, in particular by forming a first component (adding a structure component (for example a protein, a lignin, a starch or a modified lignin) to a polyphenolic component (for example a tannin)) followed by adding a second component (for example a protein) in order to form the adhesive. Temperature, pH and order of addition can be controlled in order to dissolve or disperse a component or conjugate in solution, in order to prevent or promote conjugation or complexation of components present at relevant times, and in order to obtain an orderly conjugation.

[00452] The manufacture of the adhesive first requires the formation of a first component. The first component can be formed, for example, by tannin conjugation to a protein. In other embodiments of the invention other macromolecules or modified or complexed macromolecules can be used instead of the protein. Lignin forming complex with amino acid is an example. Others may include starch, protein-lignin combination, and miscellaneous.

[00453] The formation of the first component, for example the conjugation of a tannin with a protein or a lignin complex, can be controlled by controlling the aqueous pH, the temperature, the proportion of the components and the order of addition. The specific temperature, time, and pH ranges used to control solution promotion, dissolution, conjugation, etc. may be important for first component formulation, for adhesive formation, for adhesive properties, and for composite properties. It should be noted that to a certain degree these variables are interdependent and are subject to the specific components used in a specific formulation. For example, zein and soy can both be used as the structural element but zein needs substantially more alkaline conditions to solubilize. A person skilled in the art will recognize appropriate conditions that can be used, for example, to solubilize the various components, to maintain solubilization (eg prevent clotting), and to control (eg promote or inhibit) their conjugation.

[00454] The order of addition and formation of the first component can also be important. For example, a soy-tannin:soy adhesive produced by first forming a soy-tannin complex before adding more soy results in a much superior adhesive than tannin that was simply added to an amount of soy protein equal to the sum of the 2 soy components.

[00455] The formation of the first component can be demonstrated in a number of ways. For example a zein-tannin complex can be precipitated from solution under conditions which in the absence of complexation would see the remaining tannin in solution. NMR analysis shows the magnification and intensity changes of peaks associated with tannin hydroxyl carbons (about 155 ppm) and peptide starch-carbonyls (about 175 ppm) indicating the presence of a multitude of chemical interactions and complexation through hydrogen bonding of amino groups and phenolic hydroxyls. In some embodiments of the invention, infrared spectroscopy shows peak shifts indicating ammonium formation from the hydroxyl-amino bond.

[00456] Similar effects are evident when the first component is formed by adding tannin to lysine-modified lignin, and with other formulation combinations.

[00457] In one embodiment, the process is to solubilize the structure element (for example, zein) under conditions suitable for said solubilization, then add and disperse the tannin under conditions that prevent the structure element from coagulating before the tannin is well dispersed, and then modify the conditions (for example, reduce the pH or temperature) to facilitate the formation of the conjugate.

[00458] Optionally more tannin can be added to add outstanding tannin units. The second component (for example a protein such as soy flour) is then added under conditions and/or with additives that promote the dissolution of the soy. Then the adhesive is cooled down.

[00459] The second component, for example soy protein, is typically added at an elevated temperature and the composition is held at the elevated temperature for a period of time sufficient to solubilize, dissolve, disperse, or suspend the second component and form the macromolecular complex. The temperature and period of time required can vary depending on several factors, such as the purity of the ingredient containing the second component. For ingredients of low purity with respect to the amount of the second component in the ingredient, longer heating times and/or higher temperatures may be required in order to solubilize, dissolve, disperse, or suspend the second component compared to higher purity ingredients.

[00460] In some embodiments, for example where the ingredient providing the second component comprises components different from the second component, the second component can be added to the composition at a first elevated temperature and the first temperature maintained for a period of time to promote or facilitate the solubilization, dissolution, dispersion, or suspension of at least part of the second component, after which the temperature can be adjusted to a second temperature, typically lower than the first temperature, and the second temperature maintained for a period of time to promote or facilitate the solubilization, dissolution, dispersion, or the suspension of the second additional component. The macromolecular complex can be formed throughout the heating process.

[00461] Heating after adding the second component for an extended period of time, in some embodiments, can reduce the rate at which the viscosity of the adhesive composition increases over time (in storage, prior to application to a substrate). This increases the length of time for which the adhesive composition, on storage, remains at a suitable viscosity for application to a suitable substrate.

[00462] In the case of a zein-tannin:soy protein patch, the zein component is typically first solubilized and then conjugated with the tannin. The zein-tannin conjugate is then combined with the soy protein. In order to solubilize zein in an aqueous solution generally requires a temperature of 70 to 90°C and alkaline conditions in the range of about pH 11. Then tannin can be added and the pH lowered to about 9 and the temperature reduced to 50 to 70°C to promote conjugation of polyphenols to protein. More tannin can be added. Additives such as glycerol or sodium salts can be added to promote dissolution of the soy protein. The soy protein is added and dispersed in the adhesive formulation maintaining a pH of 9 and a temperature of 70°C. The final formulation is then cooled to room temperature.

[00463] During or after cooling, the pH can be further adjusted by adding an acid (eg, formic acid) to a pH typically in a range of 3 to 9. The pH of the final formulation depends on the specific demands of the application for which the adhesive is produced. For example, plywood production requires an adhesive with a pH at the lower end of this range in order to provide greater resistance to moisture, typically a pH in the range of about 4 to 6.

[00464] In applying the adhesive to lignocellulosic substrates and curing, the components crosslink with each other and with the lignocellulosic substrate to form the hardened composite product.

[00465] The adhesive compositions described herein in this patent application can be combined with one or more additional adhesives to provide an adhesive mixture. The content of the adhesive compositions described herein in this patent application in the mixture can be determined by the other adhesive(s) present in the mixture and the mode of application for which the mixture is intended.

First components of zein-tannin

[00466] Release of zein in a soluble form followed by combination with a tannin creates a first zein-tannin component. This first zein-tannin component imparts hydrophobicity and serves as a crosslinker for the soy component in zein-tannin:soy adhesives.

[00467] In forming zein-tannin conjugate preventing protein clotting before all the tannin is added and dispersed in the solution can be achieved by manipulating the pH. Adding tannin at about pH 11 prevents protein clotting. Once the required dosage of tannin is added and dispersed in the solution, the pH can be adjusted to about pH 9. The change in pH induces conjugate formation and colloidal dispersion of the first zein-tannin component.

[00468] The zein : tannin ratio is controlled first to avoid agglomeration of zein colloids on pH adjustment. This step can be adapted and applied even when using ingredients (raw materials) with varying degrees of zein content. An additional amount of tannin can be added in order to additionally conjugate the zein and create residual/free pendant tannin units, not forming complexes available for coordination of additional protein in the addition of soy protein.

First components of lignin-tannin

[00469] In one embodiment, lignin is first coupled with an amine compound such as lysine and then the pH is adjusted to ensure conjugation of the lignin with the amine compound. Tannin is then added.

[00470] Conjugation of phenolid hydroxyl lignin with amide and amino groups present in proteins, peptide residues and amino acids can modify lignin to aid tannin conjugation.

[00471] Variations involving enzymatic linkage can also be used, such as the use of peroxidase enzymes to promote grafting between lignin and amino groups. Tannin is then added.

[00472] This first component can be integrated into a lignin-tannin:soy or zein-lignin-tannin:soy adhesive formulation, for example, by the subsequent addition of soy protein as the second component under specified conditions.

[00473] Other synthetic methods can also be used in order to form lignin-tannin first components. For example the first lignin-tannin components can be formed synthetically by adding formaldehyde, glyoxal or other aldehydes to lignin followed by addition of tannin. An amino acid and formaldehyde can also be coupled to lignin in a Mannich reaction with the product then coupled to tannin. However, in order to avoid formaldehyde chemistry, the above methods provide a simple alternative.

First starch-tannin components

[00474] Starch components can be incorporated with tannin through the binding of residual aldehyde groups present in the carbohydrate component. In order to obtain substantially higher conjugation rates, borate-mediated binding can be used. In one embodiment, under alkaline conditions (around pH 9), boric acid is added which leads to binding of amide hydroxyls and residual tannin phenolic groups. This results in conjugation of starch and tannin through the boron center. A tannin : boric acid ratio of 20:1 appears to provide adequate properties and conjugation potential.

Zein Patches: Tannin: Soy

[00475] Zein can be used in varying purity raw materials, for example pure zein or corn and residues from corn starch processing, such as unrefined corn flour or gluten or corn bran or gluten, ground to pass through a 1 mm sieve (preferably <0.25 mm) and having a purity of at least 50% zein, more preferably 62 to 100%, with typically 62 to 70% ze materials in being commonly available.

[00476] In one embodiment, the zein ingredient (zein-containing raw material) is added to water and the pH is adjusted between 9 and 13 (preferably 11) and between 70 to 95°C (preferably 90°C). Heating is continued until all particulates are deemed to have solubilized providing a light yellow to yellow dispersion within 45 to 75 minutes (terms such as solution or suspension may equally apply here).

[00477] The initial amount of water used with the zein is typically dictated by the viscosity requirements of the final adhesive.

[00478] An initial charge of the tannin ingredient (raw material) is added to the zein dispersion while maintaining pH 11 and 90°C. The amount added can vary between 20:1 to 5:1, preferably 10:1 (of zein: tannin by weight of ingredient (raw material)).

[00479] The pH is reduced to pH 9 and the temperature is reduced to 50 to 80°C, preferably to 70°C.

[00480] A second charge of tannin ingredient is added giving a combined ingredients ratio of 7:1 to 3:1 (of zein:tannin by weight of ingredient), preferably 5:1, and completes the formation of the zein-tannin intermediate.

[00481] Glycerol or other additives can be added to ensure dispersion of soy protein and favorable properties of the formulation such as viscosity.

[00482] Maintaining pH 9 and 70°C a soy protein ingredient (raw material) is added. The soy ingredient can have a soy purity of at least 40% soy, preferably 50 to 100%, with typically 50 to 55% purity being common in soy flours or soy brans favored for making adhesives.

[00483] The amount of soy can be from 5:1 to 10:1, preferably 5:1 (soy: tannin by weight of ingredient).

[00484] In some embodiments, the soy is dispersed within 15 to 75 minutes to provide the macromolecular zein-tannin:soy complex. The actual length of time required for dispersing the soy protein in any given case will be determined by the target properties of the final target adhesive (including viscosity).

[00485] In some embodiments, the soybean is mixed at an elevated temperature of about 70°C for 30 to 60 min (for example, about 45 min), the temperature reduced to about 50°C, and heating continued for an extended period of time, such as 90 to 120 min (for example, 120 min), in order to form the macromolecular complex. Times and temperatures can be varied depending on several factors such as the purity of the soy raw material or the ingredient used.

[00486] Boric acid can be added to the formulation as it cools down to room temperature. The amount of tannin used dictates the amount of boric acid, typically being from 40:1 to 15:1, preferably 20:1 tannin : boric acid per dry weight of components, which can help conjugate and bind residual carbohydrates with tannin.

Zein adhesives : lignin : tannin : soy

[00487] Zein can be used in varying purity as described above, for example from corn and maize starch processing residues having a purity of at least 50% zein, more preferably 62 to 100%, with typically 62 to 70% of zein materials being commonly available.

[00488] In one embodiment, the zein ingredient is added to the water and the pH is adjusted between 9 and 13 (preferably 11) and between 70 to 95°C (preferably 90°C). Heating is continued until all particulates are considered solubilized providing a light yellow to brown solution dispersion within 45 to 75 minutes.

[00489] The initial amount of water used with the zein is typically dictated by the viscosity requirements of the final adhesive.

[00490] Caustic is added in order to increase the alkalinity. The caustic required is typically the amount required to dissolve the amount of lignin used that follows.

[00491] Lignin is then added to the zein solution allowing time for the lignin to become fully solubilized. Added lignin provides a ratio of 5:5 to 5:1 (zein : lignin by weight of ingredient), for example 5:3.

[00492] Then the solution is adjusted to pH 9 and a temperature of 50 to 80°C causing precipitation of the conjugate of zein and lignin.

[00493] The tannin ingredient is added giving an ingredient ratio of 2.5:1 to 6:1 (zein : tannin by weight of ingredient), preferably 3:1 to 5:1, for example 3:1, and completes the formation of the first lignin-tannin conjugate component.

[00494] Glycerol or other additives can be added to ensure dispersion of soy protein and favorable properties of the formulation such as viscosity.

[00495] Maintaining pH 9 and 70°C, a soy protein ingredient is added. The soy ingredient can have a soy purity of at least 40% soy, preferably 50 to 100%, with typically 50 to 55% purity being common in soy flours or soy brans favored for adhesives.

[00496] The amount of soy can be from 5:1 to 12:1, preferably 10:1 (soy: tannin by weight of ingredient).

[00497] In some embodiments, the soybean is dispersed within 15 to 75 minutes, for example 45 to 50 minutes, to provide the macromolecular complex. In other embodiments, the soy can be blended at the first temperature and heated at a second, lower temperature for an extended period of time to form the macromolecular complex as described above.

[00498] Boric acid can be added to the formulation as it cools down to room temperature. The amount of tannin used dictates the amount of boric acid, typically being from 40:1 to 15:1, preferably 20:1 tannin : boric acid per dry weight of components, which can help conjugate and bind residual carbohydrates with tannin.

Lignin adhesives : tannin : soy by chemical bonding

[00499] In one embodiment, a technical lignin is dissolved in water and the pH is adjusted to pH 10 to 12, preferably at least pH 10.5 with heating between 50 and 90°C.

[00500] The initial amount of water used with the lignin is typically dictated by the viscosity requirements of the final adhesive.

[00501] An amino acid such as lysine with at least 50% purity is added to the solution in an amount of 5:1 to 1:2, preferably 1:1 (lignin : lysine by weight of ingredient).

[00502] The pH is reduced to pH 9 and the temperature is reduced to 50 to 80°C, preferably 70°C.

[00503] The resulting suspension creates the lignin - amino acid conjugate.

[00504] The tannin ingredient is added giving an ingredient ratio of 2.5:1 to 6:1 (of lignin : tannin by weight of ingredient), preferably 3:1 to 5:1, for example 3:1, and completes the formation of the first lignin-tannin conjugate component.

[00505] Glycerol or other additives can be added to ensure dispersion of soy protein and favorable properties of the formulation such as viscosity.

[00506] Maintaining pH 9 and 70°C a soy protein ingredient is added. The soy ingredient will have a soy purity of at least 40% soy, more preferably 50 to 100%, with typically 50 to 55% purity being common in soy flours or soy brans favored for adhesives.

[00507] The amount of soy can be from 5:1 to 12:1, preferably 10:1 (soy: tannin by weight of ingredient).

[00508] The soybean is dispersed within 15 to 75 minutes, for example 45 to 50 minutes, to provide the macromolecular complex. In other embodiments, the soy can be blended at the first temperature and heated at a second, lower temperature for an extended period of time to form the macromolecular complex as described above.

[00509] Boric acid can be added to the formulation as it cools to room temperature. The amount of tannin used dictates the amount of boric acid, typically being from 40:1 to 15:1, preferably 20:1 tannin : boric acid per dry weight of components, which can help conjugate and bind residual carbohydrates with tannin.

Lignin adhesives : tannin : soy by enzymatic bonding

[00510] In one embodiment, a technical lignin is dissolved in water and the pH is adjusted to pH 10 to 12, preferably at least pH 10.5 with heating between 40 and 80°C.

[00511] Lysine with at least 50% purity is added to the solution in an amount of 5:1 to 1:2, preferably 1:1 (lignin:lysine by weight of ingredient).

[00512] The pH is reduced to pH 5 to 7 and the temperature is reduced to 40 to 60°C, preferably 50°C.

[00513] The resulting suspension is treated with lignin peroxidase enzyme such as laccase with an activity of 40 to 250 U/g on lignin. The laccase activity determines the duration of the reaction time between 4 to 20 hours, preferably 6 hours reaction time using 200 U/g.

[00514] The lignin is grafted with the amino acid.

[00515] The tannin ingredient is added giving a combined ingredients ratio of 2.5:1 to 6:1 (of lignin : tannin by weight of ingredient), preferably 3:1 to 5:1, for example 3:1, and completes the formation of the first lignin-tannin conjugate component.

[00516] The reaction mixture is heated to 70°C.

[00517] The remaining steps are the same as variation (a) above.

[00518] Glycerol or other additives can be added to ensure dispersion of soy protein and favorable properties of the formulation such as viscosity.

[00519] Maintaining pH 9 and 70°C a soy protein ingredient is added. The soy ingredient will have a soy purity of at least 40% soy, preferably greater than 50 to 100%, with typically 50 to 55% purity being common in soy flours or favored soy brans for adhesives.

[00520] The amount of soy can be from 5:1 to 12:1, preferably 10:1 (soy: tannin by weight of ingredient).

[00521] The soybean is dispersed within 15 to 75 minutes, for example 45 to 50 minutes, to provide the macromolecular complex. In other embodiments, the soy can be blended at the first temperature and heated at a second, lower temperature for an extended period of time to form the macromolecular complex as described above.

[00522] Boric acid can be added to the formulation as it cools down to room temperature. The amount of tannin used dictates the amount of boric acid, typically being from 40:1 to 15:1, preferably 20:1 tannin : boric acid per dry weight of components, which can help conjugate and bind residual carbohydrates with tannin.

[00523] The following non-limiting examples are provided to illustrate the present invention and in no way limit the scope thereof.

EXAMPLES Example 1. Zein MDF : tannin : soybean

[00524] Avon Gold (corn gluten meal, about 70% zein) (100 g) was added to water (450 mL) and then adjusted to pH 11 with a 40% sodium hydroxide solution. The reaction mixture was heated to 90°C for 50 minutes ensuring that a pH of 11 was maintained. After 1 hour, a mimosa tannin (10 g) was added and the solution was stirred for 10 minutes while adjusting the pH to pH 9 with a formic acid solution and reducing the temperature to 70°C. An additional charge of tannin (10g) was added and stirring was continued. Glycerol (130 mL) was added followed by addition of 7B soy flour (100 g). Stirring was continued for another 50 minutes and then the solution was cooled to room temperature. During cooling, boric acid (0.55 g) was added. The final solution was then applied as a fine spray to mechanically mixed wood fiber at a rate of 8 to 10% adhesive content over the fiber. The fiber was formed into a mattress and consolidated by hot pressing at 180°C to provide an 8 mm Medium Density Fiberboard (MDF) board with an internal bond strength of 0.45 MPa and 24 hours soaking in cold water at 29% thickness swelling, which is a board that contains no added wax sizing agent.

Example 2. Zein MDF : tannin : soybean

[00525] Avon Gold (80 g) was added to water (360 mL) and then adjusted to pH 11 with 40% sodium hydroxide solution. The reaction mixture was heated to 90°C for 50 minutes ensuring that a pH of 11 was maintained. After 1 hour a sulphited pine bark tannin (8 g) was added and the solution was stirred for 10 minutes while adjusting the pH to pH 9 with a formic acid solution and reducing the temperature to 70°C. An additional charge of tannin (8g) was added and stirring was continued. Glycerol (130 mL) was added followed by addition of 7B soy flour (about 50 to 52% soy protein) (80 g). Stirring was continued for another 50 minutes and then the solution was cooled to room temperature. During cooling, boric acid (0.48 g) was added. The final solution was then applied by mechanical mixing with wood fiber at a rate of 8 to 10% adhesive content over the fiber. The fiber was formed into a mattress and hot pressed consolidated at 210°C to provide an 8 mm medium density fiberboard with an internal bond strength of 0.55 MPa and 24 hours of cold water immersion with 31% thickness swelling.

Example 3. Lignin MDF : tannin : soybean

[00526] A lignosulfonate (30 g) was added to water at 70°C (310 ml) and adjusted to pH 11 with sodium hydroxide. Lysine sulfate (30 g) was added and after dissolution the pH was adjusted to pH 9 with formic acid. Pine bark tannin (10 g) was added and stirring was continued. After adding glycerol (120 mL), 7B soy flour (100 g) was added and stirring was continued for 60 minutes. Boric acid (0.50 g) was added and the solution was cooled. The brown solution was applied to the wood fiber at a rate of 8 to 10% adhesive content over the fiber and mechanically mixed. This fiber was hot pressed at 180°C to provide an 8 mm medium density fiber board with an internal bond strength of 0.57 MPa and 24 hours cold water soaking with 21% thickness swelling.

Example 4. Zein MDF : lignin : tannin : soybean

[00527] Avon Gold (50 g) was added to water (360 mL) and then adjusted to pH 11 with 40% sodium hydroxide solution. The reaction mixture was then heated to 90°C for 50 minutes ensuring that a pH of 11 was maintained. Caustic (sodium hydroxide) was added to give pH 12.5 and then Kraft lignin (30g) was added. After dissolution of the lignin, the pH was adjusted to pH 9 with formic acid and mimosa tannin (10 g) was added and stirring was continued. Glycerol (120 mL) was added followed by addition of soy hydrolyzate (about 90% soy protein) (55 g) and stirring was continued for 60 minutes. Boric acid (0.55 g) was added and the solution was then cooled. The brown solution was applied to the wood fiber at a rate of 8% adhesive content over the fiber and mechanically mixed. This fiber was hot pressed at 180°C to provide an 8 mm medium density fiber board having an internal bond strength of 0.37 MPa and 24 hours cold water soaking with 33% thickness swelling.

Example 5. Lignin : tannin : soy plywood panel

[00528] Lignin Indulin AT (Kraft lignin) (30 g) was added to water at 70 °C (310 mL) and adjusted to pH 11 with sodium hydroxide. Lysine sulfate (30 g) was added and after dissolution the pH was adjusted to pH 9 with formic acid. Sulfited tannin (10 g) was added and stirring was continued. After adding glycerol (120 mL), 7B soy flour (100 g) was added and stirring was continued for 60 minutes. Boric acid (0.50 g) was added and the solution was cooled. The brown solution was applied to a single face radiata pine softwood plywood at a rate of 100 g/m2. The veneers were stacked to provide a 5-ply stack and then cold pressed for 5 minutes. A plywood panel was then formed by hot pressing at 140°C. Plywood does not delaminate after 16 hours of immersion in cold water.

Example 6. Zein MDF : tannin : soybean

[00529] Avon Gold, a corn gluten meal, (1.44 kg) was dispersed in water (10.1 kg) and 40% sodium hydroxide (40%, 211 g) was added to adjust the solution to pH 11. This reaction mixture was heated to 90°C for 50 minutes maintaining pH 11. Sulphited pine bark tannin (144 g) was then added and the solution stirred for 10 minutes before adding formic acid (40%, 50 g) and reducing the temperature to 70°C. With the aqueous suspension at pH 9, additional sulphited pine bark tannin (144 g) was added and stirring was continued. Glycerol (1.9 kg) was then added followed by the careful addition of 7B soy flour (1.44 kg). Stirring was continued for 50 minutes before cooling the adhesive formulation to room temperature. During cooling, boric acid (10 g) was added. The adhesive was applied to the wood fiber by mechanical mixing at a rate of 10% adhesive content over the fiber. The fiber was formed into a mattress, pre-pressed at room temperature to 40 to 50 mm thick. The pre-pressed mattress was then hot pressed consolidated at 210°C compressing at a rate of 20 sec/mm (180 sec) to provide an 8mm medium density fiber board with an average density of 710kg/m3. Test to AS/NZS:4266 gave an internal bond strength of 0.55 MPa and an unwaxed MDF panel after 24 hours soaking in cold water with 31% thickness swelling.

Example 8. Lignin MDF : tannin : soybean

[00530] Lignosulfonate (30 g) was added to water at 70°C (310mL) and adjusted to pH 11 with sodium hydroxide. Lysine sulfate (30 g) was added and after dissolution the pH was adjusted to pH 9 with formic acid. Pine bark tannin (10 g) was added and stirring was continued. After adding glycerol (120 mL), 7B soy flour (100 g) was added and stirring was continued for 60 minutes. Boric acid (0.50 g) was added and the solution was cooled. The resulting adhesive was applied to the wood fiber by mechanical mixing at a rate of 10% adhesive content over the fiber. The fiber was formed into a mattress, pre-pressed at room temperature to a thickness of 50 mm. The pre-pressed mattress was then hot pressed consolidated at 180°C compressing at a rate of 20 sec/mm (180 sec) to provide an 8 mm medium density fiber board with an average density of 720 kg/m3. Test to AS/NZS:4266 gave an internal bond strength of 0.57 MPa and an unwaxed MDF panel after 24 hours soaking in cold water with 21% thickness swelling.

Example 9. Lignin MDF : tannin : soybean

[00531] Lignin Indulin AT (660 g) and lysine sulfate (660 g) were combined in water (7.4 kg) and sodium hydroxide (40%, 586 g) was added to obtain a pH >10.5. This solution was then adjusted to pH 7 with formic acid (40%, 470g). Enzyme laccase (46 g, 55 nkat, 203 U over lignin) was added and the solution was stirred for 6 hours at 50°C. After adjusting to pH 9 (with caustic solution - sodium hydroxide), sulphited pine bark tannin (220 g) was added and the solution was stirred for 10 minutes while heating to 70°C. Glycerol (2.9 kg) was added followed by careful addition of 7B soy flour (2.2 kg) while maintaining 70°C. After 50 minutes, boric acid (10g) was added and the adhesive formulation was then cooled to room temperature. Application of the adhesive onto wood fiber and compression at 180°C provided an 8 mm MDF panel with an average density of 670 kg/m3. This MDF panel had a measured formaldehyde emission of 0.04 mg/L as determined by the routine Japanese desiccator method in accordance with AS/NZS 4266:2004.

[00532] In the above formulation, the raw material ratio of lignin : tannin : soybean (ie ingredients) is 3:1:10 by weight of ingredients.

[00533] With this the ratio of lignin : lysine raw materials is 1:1 by weight. This corresponds to about 1 lysine per 1 lignin unit (i.e. the phenylpropyl unit which comprises the lignin unit) - i.e. about a 1:1 ratio by dry weight of the components.

[00534] Tannin is added on a unit basis. This gives a raw material ratio of lignin - tannin of 3:1 by weight.

[00535] The raw material ratio of lignin : soy protein is 3:5 by weight, since soy flour is about 50% protein.

[00536] In general the ratio of 3:1:10 by weight of raw materials corresponds to a ratio of approximately 3:1:5 by weight of the actual components (that is, the actual amount by dry weight of lignin, tannin, and soy in the respective raw materials).

[00537] The adhesives of the present invention are designed to be able to be manufactured from low-cost impure raw materials such as corn or corn residue (for zein), and soy flour or soy bran. Only some components of the raw materials can be involved in the formation of the macromolecular complex. On occasions, additional additives may be required in order to inhibit or prevent impurities in the raw materials from adversely affecting the formation or stability of the macromolecular complex. For example, boric acid can be added to aid in cross-linking starch molecules from residual carbohydrates.

Example 10. Zein : tannin : soy plywood

[00538] Avon Gold (200 g) was added to water (1105 mL) and then adjusted to pH 11 with sodium hydroxide solution (40%, 25.8 g) and heated to 90°C for 50 minutes. After 1 hour mimosa tannin (20 g) was added and the solution stirred while adjusting the pH to pH 9 with formic acid solution (40%, 5.9 g) and reducing the temperature to 70°C. Additional mimosa tannin (20 g) was added. Glycerol (260 g) and water (130 mL) were added followed by the addition of 7B soy flour (200 g). Stirring was continued for another 50 minutes while maintaining pH 9. The adhesive was then cooled to room temperature and boric acid (1.6 g) was added during cooling. The adhesive was combined with 5% wheat flour by weight and applied to radiata pine softwood plywood at a spread rate of 200 g/m2. After a 10 minute open build, the veneers were stacked to provide a 5 ply stack and then cold pressed for 5 minutes. A plywood panel was then formed by hot pressing at 160°C with 14 minutes. Tensile loading shear testing using ASTM D906-98 revealed adhesive strength properties with an average maximum load value of 1527 N and tensile stress of 2.4 MPa.

Example 11. Lignin plywood : tannin : soybean

[00539] Lignin Indulin AT (30 g) was added to 70 °C water (310 mL) and adjusted to pH 11 with sodium hydroxide. Lysine sulfate (30 g) was added and after dissolution the pH was adjusted to pH 9 with formic acid. Sulfited tannin (10 g) was added and stirring was continued. After the addition of glycerol (120 mL) 7B soy flour (100 g) was added and stirring was continued for 60 minutes. Boric acid (0.50 g) was added and the adhesive was cooled. The adhesive was applied to a single face of radiata pine softwood plywood (250 x 250 mm) at a rate of 200 g/m2. The veneers were stacked to provide a 5 ply stack and then cold pressed at 59 kN for 5. A plywood panel was then formed by hot pressing at 150°C for 10 minutes at 90 kN. Satisfactory dry glue line bond ratings were obtained in chisel test to AS/NZS 2098.2:2006 B with wood failures of 63 to 95% across all glue lines. Plywood does not delaminate after 16 hours of immersion in cold water.

Example 12. Lignin plywood : tannin : soybean

[00540] Lignosulfonate (90 g) and lysine sulfate (90 g) were added to water at 70°C (810 mL) and adjusted to pH 11 with sodium hydroxide solution (40%, 89 g). After dissolution the pH was adjusted to pH 9 with formic acid (40%, 85g) and water (170ml). Mimosa tannin (30 g) was added and stirring was continued. 7B soy flour (300 g) was added and stirring was continued for 60 minutes. Boric acid (1.6 g) was added and the adhesive was cooled. The adhesive was combined with 5% wheat flour by weight and applied to radiata pine softwood plywood at a spread rate of 200 g/m2. After a 10 minute open build, the veneers were stacked to provide a 5 ply stack and then cold pressed for 5 minutes. A plywood panel was then formed by hot pressing at 160°C with 14 minutes. Satisfactory dry glue line bond ratings were obtained in chisel testing to AS/NZS 2098.2:2006 B. Tensile loading shear testing using ASTM D906-98 revealed adhesive strength properties with an average maximum load value of 1778 N and tensile stress >2.9 MPa.

Example 13. Lignin MDF : tannin : soybean with additional viscosity modifier

[00541] Lignin Kraft (90 g) and lysine sulfate (90 g) were added to water at 70°C (656 mL) and adjusted to pH 11 with sodium hydroxide solution (40%, 66 g). After dissolution the pH was adjusted to pH 9 with formic acid (40%, 85g) and water (170ml). Sulphited pine bark tannin (30 g) was added after which sodium sulphite (10 g) was also added while stirring was continued. 7B soy flour (300 g) was added and stirring was continued for 60 minutes. Boric acid (1.6 g) was added and the adhesive was cooled. The adhesive having 36% solids and 420 cP viscosity was applied to the wood fiber and an MDF panel was pressure formed at 180°C.

Example 14. Lignin plywood : tannin : soybean

[00542] Lignin Kraft (90 g) and lysine.H2SO4 (90 g) were added to water and adjusted to pH 10.5 with caustic solution. After heating to 70°C, the pH was adjusted to pH 9 with formic acid solution and sulphited pine bark tannin (30 g) was added. After 15 minutes sodium sulphite (8.1 g) was added followed by the addition of soy flour (300 g). The solution was heated for an additional 60 minutes before cooling to 50°C. After 2 hours the solution was cooled to room temperature during which time boric acid (5g) was added to give a formulation of 34 to 40% solids. Additives from the plywood glue mix (2% modal bark flour and 1% wheat flour) were mixed into the formulation and the resulting adhesive was spread over radiata pine veneers at a spreading rate of 300 g/m2 and a panel of 3 to 5 layers stacked. After 5 minutes of open assembly, the panel was cold pressed and then hot pressed (170°C for 600 sec). The resulting plywood has a dry bond rating of 8 to 10 and a cold water immersion bond rating of at least 5 to 6 in accordance with AS/NZS 2098.2:2006.

Example 15. Zein : tannin : soy plywood

[00543] Corn gluten meal (100 g) was suspended in water, adjusted to pH 11 and heated at 90°C for 45 minutes. Sulphited pine bark tannin (10 g) was added and the pH was reduced to pH 9 with formic acid solution. After 10 minutes, an additional portion of tannin (10 g) was added and left to stir for 20 minutes. Sodium sulphite (8 g) was added followed by soy flour (300 g). The solution was heated to 70°C for 60 minutes and then cooled to 50°C while stirring was continued for an additional 2 hours. On cooling to room temperature, boric acid (1.7 g) was added to provide a formulation of 20 to 24% solids. A plywood glue mixture was formed by adding 2% modal bark flour and 1% wheat flour and the adhesive was applied to radiata pine plywood (300 g/m2). Pressing at 170°C for 600 sec seconds yielded a plywood having dry bond ratings of 8 to 10 and cold water immersion bond ratings of up to 5 as determined by AS/NZS 2098.2:2006.

Example 16. Lignin plywood : tannin : soybean

[00544] Lignin Kraft (90 g) and lysine.H2SO4 (90 g) were added to water and adjusted to pH 11.2. After heating to 70°C, the pH was adjusted to pH 9 with formic acid and tannin mimosa solution (30 g) added together with sodium sulfite (8 g). After 15 minutes soy flour (300g) was added followed by calcium carbonate (18g) and stearic acid (10g). Heating was continued for 60 minutes before cooling to 50°C. Boric acid (1.6 g) was added and the solution was stirred for an additional 2 hours before cooling to room temperature to provide a 36% solids formulation. A plywood glue mixture was formed by adding 2% modal bark flour and 1% wheat flour and the adhesive was applied to radiata pine plywood (300 g/m2). The plywood panels were pressed at 170°C for 600 seconds. Excellent wet adhesive strengths (bond ratings of 8 to 10) were achieved with cold water immersion bond ratings of 1 to 2 as determined by AS/NZS 2098.2:2006.

Example 17. Lignin plywood : tannin : soybean

[00545] Lignin Kraft (90 g) and lysine.H2SO4 (90 g) were added to water and adjusted to pH 10.9 and heated to 70°C. The pH was adjusted to pH 9 with a solution of formic acid and mimosa tannin (30g) added together with sodium sulphite (8g). Over 15 minutes soy flour (300g) calcium carbonate (18g) and zinc stearate (10g) were added and heating was continued for 60 minutes before cooling to 50°C. After stirring for 2 hours, boric acid (5 g) was added and the formulation was cooled to room temperature before further adjusting to pH 6. The formulation retained a viscosity of about 200 cP for 14 days. Plywood panels formed with this adhesive have dry bond strengths with cold water immersion bond ratings of 4 to 5 as determined by AS/NZS 2098.2:2006.

Example 18. Lignin MDF : tannin : soybean

[00546] Lignin Kraft (90 g) and lysine.H2SO4 (90 g) were added to water and adjusted to pH 11.4 on heating to 70°C. After adjusting to pH 9 with formic acid solution, sulphited Quebracho tannin (30 g) was added along with sodium sulphite (8 g) and glycerol (60 g). During 15 minutes, soy flour (300 g) and calcium carbonate (18 g) were added. Heating was continued for 60 minutes before cooling to 50°C. After stirring for 2 hours, the formulation was cooled to room temperature and boric acid (8g) was added. The formulation which had 38% solids content was divided into two portions and again adjusted to pH 6. Each had a viscosity of <300 cP after 14 days. MDF panels prepared with either formulation have internal bond strength values as determined by AS/NZS:4266 of around 0.45 MPa with resin loadings of 8 to 10%.

[00547] The proportions of the components, for example, zein:tannin or soy-lignin:tannin:protein are important to confer functionality and determine the characteristics of the adhesives of specific formulations. The specific proportions will be determined by the intended purpose and material properties of the adhesive. Typical proportions for adhesives useful for manufacturing MDF and plywood as described here.

[00548] The proportions can be expressed by dry weight of the raw materials or ingredients used in order to provide particular components of the adhesive (for example polypeptides, polysaccharides, lignins, tannins, etc.) or by dry weight of the actual components in the raw materials (for example the actual soy protein components of soy bran). The proportions are not by spring proportion. Unless otherwise stated, proportions are by dry weight of the actual components indicated in the raw material or ingredients used to provide the particular components.

[00549] The terms "ingredient" and "raw material", and related terms such as "ingredients" and "raw materials", are used interchangeably herein to refer to a composition that provides an adhesive component. The composition may consist of or consist essentially of the component. Alternatively, the composition may comprise, in addition to the component, one or more other components. For example, a soy flour ingredient or raw material providing a soy component may comprise 50% soy component (e.g. soy protein) and 50% other components (i.e. non-soy components).

Zein (Z) : tannin (T) : soy (S) ratios

[00550] With the type of raw materials (i.e., ingredients) described in the examples above, the preferred ratio for zein-tannin-soy formulation is generally approximately 5:1:5 (Z:T:S) by weight of raw materials. However, a range of proportions can be used.

[00551] Based on the weight of the raw materials, the zein to tannin ratio can be any value from about 20:1 to 3:1, preferably between 7:1 and 3:1, and most preferably about 5:1.

[00552] If the proportions are calculated by dry weight of the actual components in the raw materials (for example the actual amount of zein in a zein raw material) the proportions can change considerably.

[00553] The ratio of zein : tannin can vary between 15.5:1 to 2:1 by dry weight of the actual components in the raw materials (however, the preferred amis is around 3.9:1 in cases where a second load of tannin is added).

[00554] In terms of raw materials, the ratio of tannin to soy by weight ranges from 1:3 to 1:15, 1:3 to 1:12, or 1:4 to 1:10, preferably 1:5. This equates to a tannin : soy ratio in dry weight of actual components in the raw materials of 1:2 to 1:6 and preferably around 1 : 2.8.

[00555] In general, the ratio of zein to tannin to soy (Z:T:S) by dry weight of the actual components in the raw materials is preferably about (3 to 5) : 1 : (2 to 6). Table 1. Examples of component ratios (by weight) of components in raw materials.

Zein (Z)-lignin (L) : tannin (T) : soy (S) ratios

[00556] For the zein : lignin : tannin : soy formulations described above, the formulation can be around 5 : 3 : 1 : (3 to 15) or 5 : 3 : 1 : (3 to 12), the preferred formulation being around 5 : 3 1 : 10 (Z:L:T:S) based on the weight of the raw materials.

[00557] By dry weight of real components within the raw materials:

[00558] - The Z:L ratio is quite flexible and can vary from more than 3.7:1 to less than 0.74:1, but preferably around 1.2:1.

[00559] - The Z:T ratio can vary from 1:1 to 5:1, preferably from 1.9:1 to 4.7:1, more preferably from 2.3:1 to 3.9:1 and most preferably around 3.9:1.

[00560] - the S:T ratio will then be around 3:1 to 7:1, preferably from 2.8:1 to 6.7:1 and most preferably around 5.5:1.

[00561] Therefore, the preferred Z:L:T:S component dry weight ratio in the raw materials is approximately (1.9 to 4.7) : (2 to 5) : 1 : (2.8 to 6.7) and most preferably is about 3.6 : 3 : 1 : 5.6.

Lignin (L) : tannin (T) : soy (S) ratios

[00562] For the lignin : tannin : soy formulations described above, the preferred formulation is around (3 to 5): 1 : 10 (L:T:S) based on the weight of the raw materials.

[00563] This formulation typically includes the addition of an amino acid such as lysine (preferably at least 50% purity or more) in a ratio of 5:1 to 1:2 and preferably around 1:1 (lignin: lysine) by weight of the raw material. These ratios will be between 10:1 to 1:1 and preferably 3:1 by dry weight of lysine and lignin in the lysine and lignin feedstocks.

[00564] By weight of raw material, tannin is added to provide an ingredient ratio of 2.5:1 to 6:1 (lignin:tannin), preferably between 3:1 and 5.1:1, and most preferably around 3:1. The lignin:tannin ratio by dry weight of lignin and tannin in the lignin and tannin feedstocks can range from 2:1 to 7:1, preferably 2.6:1 to 6.3:1. More preferably from 3:1 to 5.3:1 and most preferably around 3.2:1.

[00565] By weight of raw material, soy protein is added to bring the ratio of soy : tannin to between 3:1 to 15:1, 3:1 to 12:1, or 5:1 to 12:1, preferably around 10:1. The ratio of soy:tannin per dry weight of soy and of tannin in the soy and tannin raw materials are between 2:1 to 7:1, preferably between 2.8:1 to 6.7:1 and most preferably around 5.6:1.

[00566] The use of formaldehyde chemistry results in modifications to the proportions. In an adhesive using formaldehyde chemistry, each of the following lignin to soybean tannin (L:T:S) formulations were prepared. These vary from the various lignin:tannin and soy:tannin ratios described in the previous examples.

[00567] Lignin, lysine and formaldehyde were added to water and adjusted to pH 10.5. The Mannich-type reaction was carried out by heating for 4 hours at 90°C before cooling to 70°C and adjusting to pH 9. The remaining addition of tannin, soy flour and any other additives followed the examples described above. Table 2. Various lignin : tannin : soybean formulations (by dry weight of actual components in the raw materials)

[00568] In the above example, formaldehyde was used to promote lignin-lysine crosslinking through a Mannich-type reaction.

[00569] Alternatively, lignin and tannin can be directly coupled together by reaction. One method is reaction of lignin with an aldehyde followed by tannin coupling. Another example of lignin and tannin grafting is the lignin-glyoxal-tannin reaction in which lignin and glyoxal are first reacted and then the reaction product is coupled with tannin.

[00570] The addition of additives such as formaldehyde may necessitate an adjustment in the component proportions. In the above case, as formaldehyde adds crosslinking, the soy component can be higher.

[00571] Adhesives can be applied by atomization to wood fiber, particles, flakes and filaments by mechanical mixing or through a blowing line and the resin-bonded wood product molded into a mattress before hot pressing.

[00572] Adhesives can also be applied by spray, roller or curtain coating of wood veneers followed by plywood jointing and pressing to provide plywood, laminated plywood lumber, over layers of plywood or other plywood products.

[00573] Consolidation through hot pressing can use a range of temperatures, closing rates and waiting times specific to the wood panel product that ensures dehydration and curing of the adhesive component with densification of the wood product (wood furnish) or plywood in the formation of the panel.

[00574] In another embodiment, an adhesive composition or adhesive precursor composition as described herein, in this patent application, can be applied in aqueous or powder form to traditional adhesives and resins such as urea formaldehyde resin and then applied to wood or veneer furniture in the usual manner.

[00575] Adhesives of the type described can be applied to wood fiber, particles and plywood, etc. using routine application methods and equipment and can be pressed and cured according to pressing schemes not substantially different from those currently used in industry.

[00576] For the adhesive to fully adjust to provide final crosslinking and bonding between the composite components, the adhesive after application is at least partially dehydrated. Dehydration can be performed by loss of water and migration of water to the lignocellulosic substrate and by heat applied in the compression and curing stages involved in the formation of composites.

[00577] After adding the protein or protein-rich or amino acid component, the adhesive is in the form of an aqueous suspension or dispersion. The formulations can be used directly or stored (eg for a finite period, preferably at 20°C or below) or dried to a powder for reconstitution at the point of application.

[00578] The resulting wood composites have material properties substantially similar to those produced with formaldehyde-based resins.

[00579] It is not the intention to limit the scope of the invention to the above mentioned examples only. As would be recognized by a person skilled in the art, many variations are possible without departing from the scope of the invention.

Claims (24)

1. Aqueous adhesive composition, characterized in that it comprises a macromolecular complex comprising: (A) a first component comprising: (i) a structural element selected from (a) a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof, (b) a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof, or a saccharide conjugate comprising a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof and a first linker molecule, and (c) a lignin, a lignan or a lignin conjugate comprising a lignin and a second linker molecule; and (ii) a polyphenol comprising a tannin, a tannic acid, a flavonoid, a polyresorcinol or any combination of any two or more thereof; and (B) a second component comprising a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof; wherein the ratio of frame element to polyphenol is from 20:1 to 1:1 dry weight; and wherein the ratio of polyphenol to second component is from 1:1 to 1:8 dry weight. 2. Aqueous adhesive composition according to claim 1, characterized in that the ratio of structure element (a) to polyphenol is from 15.5:1 to 2:1 in dry weight. 3. Aqueous adhesive composition according to claim 1, characterized in that the ratio of structure element (b) to polyphenol is from 3:1 to 7:1 in dry weight. 4. Aqueous adhesive composition according to claim 1, characterized in that the proportion of structure element (c) to polyphenol is from 7:1 to 2:1 in dry weight. 5. Aqueous adhesive composition according to any one of claims 1 to 4, characterized in that the first linker molecule and the second linker molecule are each independently selected from: (a) a polypeptide, an oligopeptide, an amino acid, or any combination of any two or more thereof; (b) an inorganic polyhydroxy nonmetallic compound or an ester or salt thereof; (c) an amine compound or a salt thereof; (d) a thiol compound or a salt thereof; (e) a metal ion; (f) an aldehyde compound; or a carboxylic acid compound or a salt, ester, anhydride or halide thereof; and (g) any combination of any two or more thereof. 6. Aqueous adhesive composition according to claim 5, characterized in that: the first linker molecule is a compound of polyhydroxylated boron, phosphorus, silicon, or sulfur or an ester or salt thereof; or the second linker molecule is an amine compound selected from a natural amino acid, an unnatural amino acid having at least 2 carbon atoms, a polyamine having at least 2 carbon atoms, and a hydroxyamine having at least 2 carbon atoms, or a salt thereof; or the second linker molecule is a thiol compound comprising at least two carbon atoms; a thiol group; and at least one additional functional group capable of forming covalent or non-covalent bonds in the lignin conjugate; or the second linker is an aldehyde comprising from 1 to 12 carbon atoms; or the second linker comprises an aldehyde comprising from 1 to 12 carbon atoms and an amine compound; or the second linker molecule comprises a polyhydroxy boron, phosphorus, silicon, or sulfur compound or an ester or salt thereof and a carboxylic acid compound or a salt, ester, anhydride, or halide thereof. 7. Aqueous adhesive composition according to any one of claims 1 to 6, characterized in that the second component, the element of structure (a), the first linker molecule, or the second linker molecule comprises a polypeptide or an oligopeptide of zein, soy, keratin, gluten, casein, or whey, or any combination of any two or more thereof. 8. Aqueous adhesive composition according to any one of claims 1 to 7, characterized in that the polyphenol comprises a tannin or a mixture of a tannin and a lignin. 9. Aqueous adhesive composition according to any one of claims 1 to 8, characterized in that the composition comprises one or more protein denaturing agents. 10. Aqueous adhesive composition according to any one of claims 1 to 9, characterized in that the composition comprises one or more additives selected from the group consisting of organic solvents, surfactants, dispersants, viscosity modifiers, and hydrophobizing agents. 11. Process for producing an aqueous adhesive composition comprising a macromolecular complex, characterized in that the process comprises: (1) providing an aqueous composition comprising a first component, the first component comprising: (i) a structural element selected from (a) a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof, (b) a polysaccharide, an oligosaccharide, a monosaccharide, or any combination thereof any two or more thereof, or a saccharide conjugate comprising a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof and a first linker molecule, (c) a lignin, a lignan or a lignin conjugate comprising a lignin and a second linker molecule; and (ii) a polyphenol comprising a tannin, a tannic acid, a flavonoid, a polyresorcinol or any combination of any two or more thereof; and (2) mixing a second component comprising a polypeptide, an oligopeptide, an amino acid, a polyamine, or any combination of any two or more thereof to form a macromolecular complex; wherein the ratio of frame element to polyphenol is from 20:1 to 1:1 dry weight; and wherein the ratio of polyphenol to second component is from 1:1 to 1:8 dry weight. 12. Process according to claim 11, characterized in that step (1) comprises: (a) providing an aqueous composition comprising the structure element; (b) mixing the polyphenol to form the first component. 13. Process according to claim 12, characterized in that step (1)(a) comprises: (i) providing an aqueous composition comprising (a) a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof, or (b) a first linker molecule; and (ii) mixing the other of (a) or (b) to form a saccharide conjugate; or (iii) providing an aqueous composition comprising (a) a lignin or (b) a second linker molecule; and (iv) mixing the other of (a) or (b) to form a lignin conjugate. 14. Process according to any one of claims 11 to 13, characterized in that the provision of step (1), (1)(a), or (1)(a)(i), or any combination of any two or more thereof, comprises solubilization, dissolution, dispersion, or suspension of the first component, the structural element, the polysaccharide, the oligosaccharide, the monosaccharide, or any combination of any two or more thereof, the first chainer molecule, lignin, or the second chain linker molecule in an aqueous solution. 15. Process according to claim 14, characterized in that the mixing of step (2), (1)(b), or (1)(a)(ii), or any combination of any two or more thereof, is carried out at alkaline pH or at a temperature of at least 50°C, or both. 16. Process according to claim 15, characterized in that the pH is from 8 to 13. 17. Process according to claim 15 or 16, characterized by the fact that the temperature is from 50 to 95°C. 18. Process according to any one of claims 11 to 17, characterized in that the mixing of step (2), (1)(b), or (1)(a)(ii), or any combination of any two or more thereof additionally comprises adjusting one or more conditions in order to form the macromolecular complex, the first component, the saccharide conjugate, or the lignin conjugate. 19. Process according to claim 18, characterized in that the adjustment of one or more conditions comprises the reduction of pH or temperature or both. 20. Process according to any one of claims 11 to 19, characterized in that the mixing of step (2), (1)(b), or (1)(a)(ii), or any combination of any two or more thereof further comprises mixing a second additional component, an additional polyphenol, a polysaccharide, an oligosaccharide, a monosaccharide, or any combination of any two or more thereof additional, a first additional linker, an additional lignin, or a second link additional donor. 21. Process according to any one of claims 11 to 20, characterized in that the mixing of step (2), (1)(b), or (1)(a)(ii), or any combination of any two or more thereof, is carried out under conditions that inhibit or prevent coagulation in the reaction mixture. 22. Process according to any one of claims 11 to 21, characterized in that the second component is mixed in combination with or after mixing one or more additives that enhance the solubilization, dissolution, dispersion, or suspension of the second component. 23. Lignocellulosic composite, characterized in that it comprises fibers, particles, flakes, filaments, flakes or lignocellulosic sheets and a dehydrated or partially dehydrated adhesive composition as defined in any one of claims 1 to 10, wherein the composite is a particle board, an oriented particle board, a board of inserts, a fiber board, a sawn wood of parallel strands, a sawn wood of laminated wires, a plywood, a laminated plywood lumber, a finger-jointed lumber, a scrimber board, a paperboard, a corrugated board, or other engineered wood product or engineered wood product board. 24. Process for producing a lignocellulosic composite, characterized in that the process comprises applying the adhesive composition as defined in any one of claims 1 to 10 to fibers, particles, flakes, filaments, flakes, or lignocellulosic sheets; and forming a composite of the fibers, particles, flakes, filaments, chips, or sheets, wherein forming the composite comprises applying heat, or pressure, or both, wherein the applied heat is from a temperature of 120 to 250°C to dehydrate or partially dehydrate and cure the adhesive composition.