EP4638637A1

EP4638637A1 - Improved bonding resin

Info

Publication number: EP4638637A1
Application number: EP23906209.4A
Authority: EP
Inventors: Ashar ZAFAR; Dimitri Areskogh; Huynh Tram Anh PHAM
Original assignee: Stora Enso Oyj
Current assignee: Stora Enso Oyj
Priority date: 2022-12-19
Filing date: 2023-12-18
Publication date: 2025-10-29
Also published as: SE2230424A1; WO2024134449A1; SE546258C2

Abstract

The present invention relates to a bonding resin useful for example in the manufacture of insulation, such as mineral wool insulation or glass wool insulation. The invention also relates to a method for preparing the bonding resin and to the use thereof.

Description

IMPROVED BONDING RESIN Field of the invention The present invention relates to a bonding resin useful for example in the 5 manufacture of insulation, such as mineral wool insulation or glass wool insulation. The invention also relates to a method for preparing the bonding resin and to the use thereof. Background 10 Bonding resins are useful in fabricating articles, because they are capable of consolidating non- or loosely- assembled matter. For example, bonding resins enable two or more surfaces to become united. In particular, bonding resin may be used to produce products comprising consolidated fibers. 15 Thermosetting bonding resins may be characterized by being transformed into insoluble and infusible materials by means of either heat or catalytic action. Examples of thermosetting bonding resins include a variety of phenol- aldehyde, urea-aldehyde, melamine-aldehyde, and other condensation- polymerization materials like polyurethane resins. Bonding resins containing 20 phenol-aldehyde, resorcinol-aldehyde, phenol/aldehyde/urea, phenol/melamine/aldehyde, and the like are used for the bonding of fibers, textiles, plastics, rubbers, and many other materials. The mineral wool and fiber board industries have historically used phenol- 25 formaldehyde bonding resins to bind fibers. Phenol-formaldehyde type bonding resins provide suitable properties to the final products; however, environmental considerations have motivated the development of alternative binders. One such alternative bonding resin is a carbohydrate-based binder derived from reacting a carbohydrate and a multiprotic acid, for example according to US2007/0027283 and WO2009/019235. Another alternative bonding resin is the esterification products of a polycarboxylic acid reacted with a polyol, for example according to US2005/0202224. Since these binders do not utilize formaldehyde as a reagent, they have been collectively referred 5 to as formaldehyde-free binders. One area of development is to find a replacement for the phenol- formaldehyde type binders across the entire range of products in which they are used (e.g. fiberglass insulation, particle boards, office panels, and 10 acoustical sound insulation). In particular, the previously developed formaldehyde-free bonding resins may not possess all the desired properties for all the products. For example, acrylic acid and poly(vinylalcohol) based binders have shown promising performance characteristics. However, these are relatively more expensive than phenol-formaldehyde binders, are derived 15 essentially from petroleum-based resources, and have a tendency to exhibit lower reaction rates compared to the phenol-formaldehyde based bonding resins (requiring either prolonged cure times or increased cure temperatures). Carbohydrate-based bonding resins are made of relatively inexpensive precursors and are derived mainly from renewable resources; however, these 20 bonding resins may also require reaction conditions for curing that are substantially different from those conditions under which the traditional phenol-formaldehyde binder system cured. Therefore, replacement of phenol- formaldehyde type binders with an existing alternative has not been readily achievable. 25 Lignin, an aromatic polymer is a major constituent in e.g. wood, being the most abundant carbon source on Earth second only to cellulose. In recent years, with development and commercialization of technologies to extract lignin in a highly purified, solid and particularized form from the pulp-making 30 process, it has attracted significant attention as a possible renewable substitute to primarily aromatic chemical precursors currently sourced from the petrochemical industry. Lignin, being a polyaromatic network, has been extensively investigated as a suitable substitute for phenol during production of phenol-formaldehyde adhesives. These are used during manufacturing of laminate and structural wood products such as plywood, oriented strand board and fiberboard. During 5 synthesis of such adhesives, phenol, which may be partially replaced by lignin, is reacted with formaldehyde in the presence of either basic or acidic catalyst to form a highly cross-linked aromatic resins termed novolacs (when utilizing acidic catalysts) or resoles (when utilizing basic catalysts). Currently, only limited amounts of the phenol can be replaced by lignin due to the lower 10 reactivity of lignin. Tannins are phenolic-based natural products. They are found mostly in the bark of pine, the wattle of mimosa and hemlock and in the wood of certain trees such as quebracho and sumach. The extraction of these substances 15 leads to a mixture of oligo-and poly flavonoids which are known as condensed tannins, with number average molecular weights ranging from 1000 to 4000 depending on the species which generated them. Given the phenolic-type structures borne by these oligomers, the use of tannin as macromonomers in formulations involving the characteristic phenol- 20 formaldehyde condensation reactions has been suggested. Much experience has been gained on the making and properties of tannin-based resins. These include a number of combinations, such as phenol-formaldehyde, resorcinol- formaldehyde, urea-formaldehyde prepolymers and also mixtures therefrom to which tannins or tannin-formaldehyde resols are added: in a basic medium 25 these mixtures cure at room temperature to networks which possess good adhesive properties, particularly for plywood. Although cold curing ensures most of the network formation, it was shown that further condensation occurs when one heats these materials at about 130 °C. 30 A problem when preparing insulation products is to obtain appropriate strength properties, which largely depend on the bonding resin used, without the use of formaldehyde. In addition, there is a need to improve reactivity compared to prior art resins. Further, the bonding resin should preferably be bio-based. 5 Summary of the invention It has now surprisingly been found that it is possible to easily prepare a bonding resin, suitable for example for use in the production of insulation, in which the use of formaldehyde can be avoided. It has also been found that 10 the bonding resin provides improved wet strength properties and improved balance between dry strength and wet strength properties, making it particularly useful in the manufacture of insulation. Further, it has been found that the strength properties can be improved by including epoxy-based crosslinker in the bonding resin. In addition, it has surprisingly been found that 15 the use of carbohydrate reactant can be avoided. It has been found that a solution of lignin and/or tannin in ammonia or organic base is compatible with polyamines useful in the preparation of a bonding resin and improves the reactivity or reaction speed of the bonding resin. 20 Further, it has been found that when lignin and/or tannin is provided in the form of an aqueous solution comprising ammonia and/or organic base, the phenolic hydroxyl groups in the lignin and/or tannin structure are deprotonated and free to react with other components of a bonding resin. 25 Furthermore, by providing lignin and/or tannin in the form an aqueous solution of lignin and/or tannin comprising ammonia and/or an organic base the risk of degrading for example glass wool and mineral wool fibers is minimized. The present invention is thus directed to a bonding resin comprising a 30 reaction product of lignin and/or tannin, epoxy-based crosslinker and a polyamine, wherein the polyamine is a primary polyamine selected from a group consisting of a diamine, triamine, tetraamine and pentaamine, and wherein the polyamine is H2N-Q-NH2, wherein Q is C1-C10 alkyl, cycloalkyl, C1-C10 heteroalkyl, or cycloheteroalkyl, each of which is optionally substituted; and wherein the lignin and/or tannin is provided as a solution and wherein the total amount of lignin and/or tannin in the bonding resin, calculated on the 5 basis of dry lignin and/or tannin and dry bonding resin, is in the range of from 5 wt-% to 90 wt-%, such as 20-90 wt-% or preferably 30-80 wt-% or 50-80 wt- %, and wherein the bonding resin does not comprise monosaccharide, disaccharide or oligosaccharide and wherein the lignin is not chemically modified after its extraction from wood and isolation. 10 The present invention is also directed to a fibrous insulation product comprising the bonding resin according to the present invention. Detailed description 15 It is intended throughout the present description that the expression "lignin" embraces any kind of lignin, e.g. lignin originated from hardwood, softwood or annular plants. Preferably the lignin is an alkaline lignin generated in e.g. the Kraft process. Preferably, the lignin has been purified or isolated before being used in the process according to the present invention. The lignin may be 20 isolated from black liquor and optionally be further purified before being used in the process according to the present invention. The purification is typically such that the purity of the lignin is at least 90%, preferably at least 95%. Thus, the lignin used according to the method of the present invention preferably contains less than 10%, preferably less than 5% impurities. The lignin may 25 then be separated from the black liquor by using the process disclosed in WO2006031175. The lignin may then be separated from the black liquor by using the process referred to as the LignoBoost process. The lignin may be provided in the form of particles, such as particles having an average particle size of from 50 micrometers to 500 micrometers. 30 The tannin used in the present invention is a general term of complicated aromatic compounds having a large number of phenolic hydroxyl groups. Tannins are widely distributed in the plant kingdom, and to roughly divide, tannin is divided into two kinds of a hydrolyzed type and a condensed type. Both kinds are natural compounds, and have different structures. Either tannin may be used in the present invention. Polyhydric phenol compounds 5 having a dye-fixing effect and a tanning effect of leather are called "synthetic tannin" and "cintan", and among the synthetic tannins, the compounds which are effectively used can be used as well in the present invention. The lignin used according to the present invention is not modified chemically. 10 An aqueous solution of lignin and/or tannin comprising ammonia and/or an organic base can be prepared by methods known in the art, such as by mixing lignin and/or tannin and ammonia and/or organic base with water. The pH of the aqueous solution of lignin and/or tannin comprising ammonia and/or 15 an organic base is preferably in the range of from 8 to 14, more preferably in the range of from 9 to 11 or 10 to 11. Examples of organic bases include amines, such as primary, secondary and tertiary amines and mixtures thereof. Preferably, the organic base is selected from the group consisting of methylamine, ethylamine, propylamine, butylamine, ethylenediamine, 20 methanolamine, ethanolamine, aniline, cyclohexylamine, benzylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dimethanolamine, diethanolamine, diphenylamine, phenylmethylamine, phenylethylamine, hexamethylenediamine, polyetheramine, dicyclohexylamine, piperazine, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-25 isopropylimidazole, 2-phenylimidazole, 2-methylimidazoline, 2- phenylimidazoline, trimethylamine, triethylamine, dimethylhexylamine, N- methylpiperazine, dimethylbenzylamine, aminomethyl propanol, tris(dimethylaminomethyl)phenol and dimethylaniline or mixtures thereof. The total amount of ammonia and/or organic base in the aqueous solution is 30 preferably in the range of from 0.1 wt-% to 20 wt-%, preferably 0.1 wt-% to 10 wt-%, of the total weight of the aqueous solution comprising water, lignin and/or tannin and ammonia and/or an organic base. The total amount of lignin and/or tannin in the aqueous solution of lignin and/or tannin comprising ammonia and/or an organic base is preferably from 1 wt-% to 60 wt-% of the solution, such as from 10 wt-% to 30 wt-% of the solution. The aqueous solution of lignin and/or tannin comprising ammonia and/or an organic base comprises less than 1 wt-% alkali and less than 1 wt-% inorganic base. More preferably, the aqueous solution of lignin and/or tannin comprising ammonia and/or an organic base does not comprise alkali and does not comprise inorganic base. The total amount of lignin and/or tannin in the bonding resin is preferably from 5 wt-% to 90 wt-%, such as 20-90 wt-% or preferably 30-80 wt-% or 50-80 wt- %, calculated as the total dry weight of lignin and/or tannin and the total weight of the bonding resin. As used herein, a polyamine is an organic compound having two or more amine groups. As used herein, a primary polyamine is an organic compound having two or more primary amine groups (-NH2). Within the scope of the term primary polyamine are those compounds which can be modified in situ or isomerize to generate a compound having two or more primary amine groups (-NH2). The polyamine is a primary polyamine. The polyamine used in the bonding resin according to the present invention may be a molecule having the formula of H2N-Q-NH2, wherein Q is an alkyl, cycloalkyl, heteroalkyl, or cycloheteroalkyl, each of which may be optionally substituted. In one embodiment, Q is an alkyl selected from a group consisting of C2-C24 alkyl. In one embodiment, Q is an alkyl selected from a group consisting of C2-C8 alkyl. In one embodiment, Q is an alkyl selected from a group consisting of C3-C7 alkyl. In one embodiment, Q is a C6 alkyl. In one embodiment, Q is selected from the group consisting of a cyclohexyl, cyclopentyl or cyclobutyl. In one embodiment, Q is a benzyl. As used herein, the term "alkyl" includes a chain of carbon atoms, which is optionally branched. The alkyl is of limited length, including C1-C24, C1-C12, C1-C8, C1-C6, or C1-C4. Shorter alkyl groups may add less hydrophilicity to the compound and accordingly will have different reactivity and solubility in a binder solution. As used herein, the term "cycloalkyl" includes a chain of carbon atoms, which 5 is optionally branched, where at least a portion of the chain in cyclic. Cycloalkylalkyl is a subset of cycloalkyl. Cycloalkyl may be polycyclic. Examples of cycloalkyls include, but are not limited to, cyclopropyl, cyclopentyl, cyclohexyl, 2-methylcyclopropyl, cyclopentyleth-2-yl, adamantyl, and the like. Chain forming cycloalkyl is of limited length, including C³-C²⁴, C³- 10 C12, C3-C8, C3-C6, or C5-C6. Shorter alkyl chains forming cycloalkyl may add less lipophilicity to the compound and accordingly will have different behavior. As used herein, the term "heteroalkyl" includes a chain of atoms that includes both carbon and at least one heteroatom, and is optionally branched. 15 Illustrative heteroatoms include nitrogen, oxygen, and sulfur. Illustrative heteroatoms also include phosphorus, and selenium. In one embodiment, a heteroalkyl is a polyether. As used herein, the term "cycloheteroalkyl" including heterocyclyl and heterocycle, includes a chain of atoms that includes both carbon and at least one heteroatom, such as heteroalkyl, and is 20 optionally branched, where at least a portion of the chain is cyclic. Illustrative heteroatoms include nitrogen, oxygen, and sulfur. Illustrative heteroatoms also include phosphorus, and selenium. Illustrative cycloheteroalkyl include, but are not limited to, tetrahydrofuryl, pyrrolidinyl, tetrahydropyranyl, piperidinyl, morpholinyl, piperazinyl, homopiperazinyl and the like. 25 The term "optionally substituted" as used herein includes the replacement of hydrogen atoms with other functional groups on the radical that is optionally substituted. Such other functional groups illustratively include, but are not limited to, amino, hydroxyl, halo, thiol, alkyl, haloalkyl, heteroalkyl, aryl, 30 arylalkyl, arylheteroalkyl, nitro, sulfonic acids and derivatives thereof, carboxylic acids and derivatives thereof, and the like. Illustratively, any of amino, hydroxyl, thiol, alkyl, haloalkyl, heteroalkyl, aryl, arylalkyl, arylheteroalkyl, and/or sulfonic acid is optionally substituted. In one embodiment of the present invention, the polyamine is selected from a group consisting of a diamine, triamine, tetraamine, and pentamine. In one embodiment, the polyamine is a diamine selected from a group consisting of 5 hexamethylenediamine, 1,6-diaminohexane,1,5-diamino-2-methylpentane and 3-(aminomethyl)-3,5,5-trimethylcyclohexan-1-amine. In one embodiment, the diamine is 1,6-diaminohexane. In one embodiment, the polyamine is a triamine selected from a group consisting of diethylenetriamine, 1- piperazineethaneamine, and bis(hexamethylene)triamine. In one 10 embodiment, the polyamine is a tetramine such as triethylenetetramine. In one embodiment, the polyamine is a pentamine, such as tetraethylenepentamine. In one embodiment, the primary polyamine is a polyether-polyamine, i.e. an amine terminated polyether or diamines and triamines attached to a polyether backbone. In one embodiment, the 15 polyether-polyamine is a diamine or a triamine. Examples of polyether- polyamine include polyoxypropylene triamine, polyoxypropylene diamine, triethylene glycol diamine. The weight ratio of the lignin and/or tannin to polyamine, calculated on the 20 basis of dry solids, is between 100:1 and 1:100, preferably in the range of from 20:1 to 1:20 and more preferably in the range of from 10:1 to 1:10, most preferably in the range of from 2:1 to 10:1, such as from 1:1 to 5:1 or from 2:1 to 5:1. 25 The epoxy-based crosslinker is preferably selected from glycerol diglycidyl ether, polyglycerol polyglycidyl ether, glycerol triglycidyl ether, sorbitol polyglycidyl ether, alkoxylated glycerol polyglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolpropane diglycidyl ether, polyoxypropylene glycol diglycidylether, polyoxypropylene glycol triglycidyl ether, diglycidylether of 30 cyclohexane dimethanol, resorcinol diglycidyl ether, isosorbide diglycidyl ether, pentaerythritol tetraglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether having 2-9 ethylene glycol units, propylene glycol diglycidyl ether having 1-5 propylene glycol units, diglycidyl-, triglycidyl- or polyglycidyl- ether of a carbohydrate, diglycidyl-, triglycidyl- or polyglycidyl-ester of a carbohydrate, diglycidyl-ether or diglycidyl ester of salicylic acid, vanillic acid, or 4-hydroxybenzoic acid, an epoxidized or glycidyl substituted plant-based phenolic compound or epoxidized plant- 5 based oil, tris(4-hydroxyphenyl) methane triglycidyl ether, N,N-bis(2,3- epoxypropyl)aniline, p-(2,3-epoxypropoxy-N,N-bis(2,3-epoxypropyl)aniline, diglycidyl ether of bis-hydroxymethylfuran, and/or diglycidyl ether of terminal diol having a linear carbon chain of 3-6 carbon atoms. 10 The weight ratio of the epoxy-based crosslinker to the lignin and/or tannin is preferably in the range of from 1:100 to 100:1, more preferably in the range of from 1:100 to 10:1, such as from 2:100 to 1:1 or from 5:100 to 1:1, calculated on the basis of dry solids. 15 The solid content of the bonding resin before curing is preferably in the range of from 10 to 70%, such as in the range of from 15 to 50%. The bonding resin may also comprise additives, such as urea, tannin, surfactants, dispersing agents and fillers. The bonding resin may also 20 comprise plasticizer. In one embodiment, the bonding resin does not comprise plasticizer. As used herein, the term “plasticizer” refers to an agent that, when added to lignin and/or tannin, makes the lignin and/or tannin softer and more flexible, to increase its plasticity by lowering the glass transition temperature (Tg) and improve its flow behavior. Examples of plasticizers 25 include polyols, alkyl citrates, organic carbonates, phthalates, adipates, sebacates, maleates, benzoates, trimellitates and organophosphates. Polyols include for example polyethylene glycols, polypropylene glycols, glycerol, diglycerol, polyglycerol, butanediol, sorbitol and polyvinyl alcohol. Alkyl citrates include for example triethyl citrate, tributyl citrate, acetyl triethyl citrate 30 and trimethyl citrate. Organic carbonates include for example ethylene carbonate, propylene carbonate, glycerol carbonate and vinyl carbonate. Further examples of plasticizers include polyethylene glycol ethers, polyethers, triacetin and solvents used as coalescing agents like alcohol ethers. In one embodiment of the present invention, the plasticizer is a polyol, such as a polyol selected from the group consisting of polyethylene glycols and polypropylene glycols. If the resin comprises a plasticizer, the weight ratio between plasticizer and 5 lignin and/or tannin, calculated on the basis of dry weight of each component, is preferably from 0.1:10 to 10:1. Preferably, the weight ratio between plasticizer (if present) and lignin and/or tannin, calculated on the basis of dry weight of each component, is from 0.1:10 to 10:10, such as from 1:10 to 5:10. The bonding resin may also comprise coupling agent. Coupling agents are for 10 example silane-based coupling agents. In one embodiment, the bonding resin does not comprise coupling agent. Preferably, the bonding resin according to the present invention does not 15 contain formaldehyde. Preferably, the bonding resin does not contain phenol. Preferably, the bonding resin according to the present invention does not contain basic catalyst. Further, it is preferred that a basic catalyst is not used in the production of the bonding resin according to the present invention. 20 The bonding resin according to the present invention does not contain carbohydrate reactant selected a from monosaccharide, a disaccharide or an oligosaccharide. 25 The fibrous material used according to the present invention is for example mineral fibers (such as glass fibers, slag wool fibers, and rock wool fibers), aramid fibers, ceramic fibers, metal fibers, carbon fibers, polyimide fibers, polyester fibers, and rayon fibers. Such fibers are substantially unaffected by exposure to temperatures above about 120 °C. In one 30 embodiment, the insulating fibers are glass fibers. In one embodiment, the insulating fibers are rock wool fibers. In one embodiment, the mineral fibers are present in an insulation product according to the present invention in the range from about 70% to about 99% by weight. In one embodiment, fibrous material comprises cellulosic fibers. For example, the cellulosic fibers may be wood fibers, wood shavings, sawdust, wood pulp, or ground wood. In one embodiment, the cellulosic fibers may be other 5 natural fibers such as jute, flax, hemp, and straw. As used herein, the term binder solution is the solution of chemicals which can be substantially dehydrated to form an uncured bonding resin. As used herein, the bonding resin may be cured, uncured, or partially cured. The 10 composition of the uncured bonding resin is referred to as an uncured bonding resin. An uncured bonding resin is a substantially dehydrated mixture of chemicals which can be cured to form a cured bonding resin. Substantially dehydrated means that the solvent (typically water or a mixture comprising water) used to make the binder solution is vaporized to the extent that the 15 viscosity of the remaining material (comprising the binder reactants and solvent) is sufficiently high to create cohesion between the loosely assembled matter; thus, the remaining material is an uncured bonding resin. In one embodiment, the solvent is less than 65% of the total weight of the remaining material. In one embodiment, a substantially dehydrated bonding resin has a 20 moisture content between about 5% and about 65% water by weight of total binder. In one embodiment, the solvent may be less than 50% of the total weight of the remaining material. In one embodiment, the solvent may be less than 35% of the total weight of the remaining material. In one embodiment, a substantially dehydrated bonding resin has between about 10% and about 25 35% water by weight of total bonding resin. In one embodiment, the solvent may comprise less than about 20% of the total weight of the remaining material. As used herein, the term cured bonding resin describes the polymeric product 30 of curing the uncured bonding resin. The cured bonding resin may have a characteristic brown to black color and tends to absorb light over a broad range of wavelengths. Since the polymer of the cured bonding resin is extensively cross-linked, the cured bonding resin is substantially insoluble. For example, the bonding resin is essentially insoluble in water. As described herein, the uncured bonding resin provides sufficient binding capacity to consolidate fibers; however, the cured bonding resin imparts the robust, long- lasting durability and physical properties commonly associated with cross- 5 linked polymers. The bonding resin reactants described herein are soluble in water and when combined in water, a binder solution is obtained. In one embodiment, a surfactant is included in the aqueous solution to increase the solubility or 10 dispersability of one or more bonding resin reactants or additives. For example, a surfactant may be added to the aqueous binder solution to enhance the dispersibility of a particulate additive. In one embodiment, a surfactant is used to create an emulsion with a non-polar additive or binder reactant. In one embodiment, the binder solution comprises about 0.01% to 15 about 5% surfactant by weight based on the weight of the binder solution. In one embodiment, the binder solution is prepared by first mixing lignin and/or tannin in ammonia with epoxy-based crosslinker, followed by addition of polyamine. 20 In one embodiment, the binder solution is prepared by adding polyamine to a mixture of lignin and/or tannin in the form of a solution, wherein the epoxy- based crosslinker has been added to the solution before addition of polyamine. 25 The binder solutions described herein can be applied to fibrous material (e.g., sprayed onto a mat or sprayed onto the fibers as they enter a forming region), during production of fibrous insulation products. Once the binder solution is in contact with the mineral fibers the residual heat from the mineral fibers (note 30 that glass fibers for example are made from molten glass and thus may contain residual heat) and the flow of air through and/or around the product will cause a portion of the water to evaporate from the binder solution. Removing the water leaves the remaining components of the bonding resin on the fibers as a coating of viscous or semi-viscous high-solids mixture. This coating of viscous or semi-viscous high-solids mixture functions as a bonding resin. At this point, the mat has not been cured. In other words, the uncured bonding resin functions to bind the fibers in the mat. 5 The above described uncured bonding resins can be cured. For example, the process of manufacturing a cured insulation product may include a subsequent step in which heat is applied to cause a chemical reaction in the uncured bonding resin. For example, in the case of making fiberglass 10 insulation products or other mineral fiber insulating products, after the binder solution has been applied to the fibers and dehydrated, the uncured insulation product may be transferred to a curing oven. In the curing oven the uncured insulation product is heated (e.g. to from about 150°C to about 320°C), causing the bonding resin to cure. The cured bonding resin is thus a 15 formaldehyde-free, water-resistant bonding resin that binds the fibers of the fibrous insulation product together. The drying and thermal curing may occur either sequentially, simultaneously, contemporaneously, or concurrently. An uncured fiber product typically comprises about 3% to about 40% of dry 20 binder solids (total uncured solids by weight). In one embodiment, the uncured fiber product comprises about 5% to about 25% of dry binder solids. In one embodiment, the uncured fiber product comprises about 50% to about 97% fibers by weight. 25 A cured bonding resin is the product of curing the bonding resin. The term cured indicates that the bonding resin has been exposed to conditions that initiate a chemical change. Examples of these chemical changes may include, but are not limited to, (i) covalent bonding, (ii) hydrogen bonding of binder components, and (iii) chemically cross-linking the polymers and/or oligomers 30 in the bonding resin. These changes may increase the bonding resin’s durability and solvent resistance as compared to the uncured bonding resin. Curing a bonding resin may result in the formation of a thermoset material. In addition, a cured bonding resin may result in an increase in adhesion between the matter in a collection as compared to an uncured bonding resin. Curing can be initiated by, for example, heat, microwave radiation, and/or conditions that initiate one or more of the chemical changes mentioned above. 5 In a situation where the chemical change in the bonding resin results in the release of water, e.g., polymerization and cross-linking, a cure can be determined by the amount of water released above that which would occur from drying alone. The techniques used to measure the amount of water 10 released during drying as compared to when a bonding resin is cured, are well known in the art. The bonding can also be used in the manufacture of wood fiber insulation, laminates and wood products such as plywood, oriented strandboard (OSB), 15 laminated veneer lumber (LVL), medium density fiberboards (MDF), high density fiberboards (HDF), parquet flooring, curved plywood, veneered particleboards, veneered MDF or particle boards. The present invention is also directed to such wood fiber insulation, laminates, wood products such as plywood, oriented strandboard (OSB), laminated veneer lumber (LVL), 20 medium density fiberboards (MDF), high density fiberboards (HDF), parquet flooring, curved plywood, veneered particleboards, veneered MDF or particle boards manufactured using the bonding resin. The bonding resin according to the present invention may also be used in the manufacture of composites, molding compounds and foundry applications. 25 Examples Example 1 Lignin solution was prepared first by adding 211 g of powder lignin (solid 30 content 95%) and 655 g of water were added to a 1 L glass reactor at ambient temperature and were stirred until the lignin was fully and evenly dispersed. The lignin used was a kraft lignin which had not been chemically modified. Then, 30g of polyethylene glycol 300 and 104 g of 28-30% ammonia solution was added to the lignin dispersion. The composition was stirred for 60 minutes to make sure that the lignin was completely dissolved. 5 Example 2 Lignin solution was prepared first by adding 211 g of powder lignin (solid content 95%) and 685 g of water to a 1 L glass reactor at ambient temperature and stirred until the lignin was fully and evenly dispersed. The lignin used was a kraft lignin which had not been chemically modified. Then, 10 104 g of 28-30% ammonia solution was added to the lignin dispersion. The composition was stirred for 60 minutes to make sure that the lignin was completely dissolved. Example 3 15 3-Aminopropyl trimethoxysilane was diluted to 1% solution in water. Binder composition was prepared by weighing 51.3 g of lignin-ammonia solution from the example 1, 2.6 g of polyethylene glycol diglycidyl ether, 2.6 g of Polyoxypropylene triamine (Jeffamine T403) and 4 g of 1% of 3-aminopropyl trimethoxysilane into a 250 ml plastic container and was stirred with a wooden 20 stick for 2 minutes. Then, 450 g glass beads was weighed into a beaker and the lignin mixture were poured on top of the glass beads and mixed for 2 minutes. Then, the glass beads bars were prepared by putting the glass beads -binder mixture into a silicon mould for baking in an oven at 200°C for 1 hours. All glass beads bars were hard and stable after curing in the oven. The 25 size of the bar for each test is height x thickness x length: 26mm x 18mm x 103mm. Glass beads bars were post-cured for 24 hours and soaked in a water bath at 80°C for 2 hours. The glass beads bars were evaluated with 3-point bending test. The flexural 30 strength before and after water soaking is given in the Table 1. Flexural Strength Flexural Strength after without conditioning conditioning [MPa] [MPa] Glass beads bars 5.6 4.7 Table 1. Flexural Strength of the glass beads bars with and without conditioning Example 4 3-Aminopropyl trimethoxysilane was diluted to 1% solution in water. Binder composition was prepared by weighing 54.9 g of lignin-ammonia solution from the example 1, 2.75 g of polyethylene glycol diglycidyl ether, 1.4 g of Polyoxypropylene triamine (Jeffamine T403) and 4 g of 1% of 3-aminopropyl trimethoxysilane into a 250 ml plastic container and was stirred with a wooden stick for 2 minutes. Then, 450 g glass beads was weighed into a beaker and the lignin mixture were poured on top of the glass beads and mixed for 2 minutes. Then, the glass beads bars were prepared by putting the glass beads -binder mixture into a silicon mould for baking in an oven at 200°C for 1 hours. All glass beads bars were hard and stable after curing in the oven. The size of the bar for each test is height x thickness x length: 26mm x 18mm x 103mm. Glass beads bars were post-cured for 24 hours and soaked in a water bath at 80°C for 2 hours. The glass beads bars were evaluated with 3-point bending test. The flexural strength before and after water soaking is given in the Table 2. Flexural Strength Flexural Strength after without conditioning conditioning [MPa] [MPa] Glass beads bars 6.6 5.3 Table 2. Flexural Strength of the glass beads bars with and without conditioning Example 5 3-Aminopropyl trimethoxysilane was diluted to 1% solution in water. Binder composition was prepared by weighing 54.9 g of lignin solution from the example 1, 2.75 g of polyethylene glycol diglycidyl ether, 1.4 g of Jeffamine 5 D230 (Polyoxypropylene diamine) and 4 g of 1% of 3-aminopropyl trimethoxysilane into a 250 ml plastic container and was stirred with a wooden stick for 2 minutes. Then, 450 g glass beads was weighed into a beaker and the lignin mixture were poured on top of the glass beads and mixed for 2 minutes. Then, the glass beads bars were prepared by putting the glass 10 beads -binder mixture into a silicon mould for baking in an oven at 200°C for 1 hours. All glass beads bars were hard and stable after curing in the oven. The size of the bar for each test is height x thickness x length: 26mm x 18mm x 103mm. Glass beads bars were post-cured for 24 hours and soaked in a water bath at 15 80°C for 2 hours. The glass beads bars were evaluated with 3-point bending test. The flexural strength before and after water soaking is given in the Table 3. Flexural Strength Flexural Strength after without conditioning conditioning [MPa] [MPa] Glass beads bars 5.4 3.9 Table 3. Flexural Strength of the glass beads bars with and without 20 conditioning Example 6 3-Aminopropyl trimethoxysilane was diluted to 1% solution in water. Binder composition was prepared by weighing 54.9 g of lignin solution from the 25 example 1, 2.75 g of polyethylene glycol diglycidyl ether, 1.4 g of triethylene glycol diamine (Jeffamine EDR148) and 4 g of 1% of 3-aminopropyl trimethoxysilane into a 250 ml plastic container and was stirred with a wooden stick for 2 minutes. Then, 450 g glass beads was weighed into a beaker and the lignin mixture were poured on top of the glass beads and mixed for 2 minutes. Then, the glass beads bars were prepared by putting the glass beads -binder mixture into a silicon mould for baking in an oven at 200°C for 1 hours. All glass beads bars were hard and stable after curing in the oven. The 5 size of the bar for each test is height x thickness x length: 26mm x 18mm x 103mm. Glass beads bars were post-cured for 24 hours and soaked in a water bath at 80°C for 2 hours. The glass beads bars were evaluated with 3-point bending test. The flexural 10 strength before and after water soaking is given in the Table 4. Flexural Strength Flexural Strength after without conditioning conditioning [MPa] [MPa] Glass beads bars 4.9 3.8 Table 4. Flexural Strength of the glass beads bars with and without conditioning 15 Example 7 3-Aminopropyl trimethoxysilane was diluted to 1% solution in water. Binder composition was prepared by weighing 66.6 g of lignin solution from the example 2, 3.3 g of polyethylene glycol diglycidyl ether, 1.3 g of Polyoxypropylene triamine (Jeffamine T403) and 4 g of 1% of 3-aminopropyl 20 trimethoxysilane into a 250 ml plastic container and was stirred with a wooden stick for 2 minutes. Then, 450 g glass beads was weighed into a beaker and the lignin mixture were poured on top of the glass beads and mixed for 2 minutes. Then, the glass beads bars were prepared by putting the glass beads -binder mixture into a silicon mould for baking in an oven at 200°C for 1 25 hours. All glass beads bars were hard and stable after curing in the oven. The size of the bar for each test is height x thickness x length: 26mm x 18mm x 103mm. Glass beads bars were post-cured for 24 hours and soaked in a water bath at 80°C for 2 hours. The glass beads bars were evaluated with 3-point bending test. The flexural strength before and after water soaking is given in the Table 5. 5 Flexural Strength Flexural Strength after without conditioning conditioning [MPa] [MPa] Glass beads bars 5.1 5 Table 5. Flexural Strength of the glass beads bars with and without conditioning Example 6 - Reference 10 3-Aminopropyl trimethoxysilane was diluted to 1% solution in water. Binder composition was prepared by weighing 57 g of lignin solution from the example 1, 2.85 g of polyethylene glycol diglycidyl ether and 4 g of 1% of 3- aminopropyl trimethoxysilane into a 250 ml plastic container and was stirred with a wooden stick for 2 minutes. Then, 450 g glass beads was weighed into 15 a beaker and the lignin mixture were poured on top of the glass beads and mixed for 2 minutes. Then, the glass beads bars were prepared by putting the glass beads -binder mixture into a silicon mould for baking in an oven at 200°C for 1 hours. All glass beads bars were hard and stable after curing in the oven. The size of the bar for each test is height x thickness x length: 20 26mm x 18mm x 103mm. Glass beads bars were post-cured for 24 hours and soaked in a water bath at 80°C for 2 hours. The glass beads bars were evaluated with 3-point bending test. The flexural strength before and after water soaking is given in the Table 6. 25 Flexural Strength Flexural Strength after without conditioning conditioning [MPa] [MPa] Glass beads bars 3.6 3.8 Table 6. Flexural Strength of the glass beads bars with and without conditioning 5 In view of the above detailed description of the present invention, other modifications and variations will become apparent to those skilled in the art. However, it should be apparent that such other modifications and variations may be effected without departing from the spirit and scope of the invention.

Claims

Claims 1. A bonding resin comprising a reaction product of lignin and/or tannin, epoxy-based crosslinker and a polyamine, wherein the polyamine is a 5 primary polyamine selected from a group consisting of a diamine, triamine, tetraamine and pentaamine, and wherein the polyamine is H2N-Q-NH2, wherein Q is C1-C10 alkyl, cycloalkyl, C1-C10 heteroalkyl, or cycloheteroalkyl, each of which is optionally substituted; and wherein the lignin is provided as a solution and wherein the total amount of lignin 10 and/or tannin in the bonding resin, calculated on the basis of dry lignin and/or tannin and dry bonding resin, is in the range of from 1 wt-% to 90 wt-% and wherein the bonding resin does not comprise monosaccharide, disaccharide or oligosaccharide and wherein the lignin is not chemically modified after its extraction from wood and isolation. 15 2. A bonding resin according to claim 2, wherein the bonding resin further comprises a coupling agent. 3. A bonding resin according to claim 1 or 2, wherein the polyamine is20 selected from hexamethylenediamine, polyetheramine, 1,6- diaminohexane, 1,5-diamino-2-methylpentane, 3-(aminomethyl)-3,5,5- trimethylcyclohexan-1-amine, diethylenetriamine, 1- piperazineethaneamine, bis(hexamethylene)triamine, triethylenetetramine and tetraethylenepentamine. 25 4. A bonding resin according to claim 1 or 2, wherein the polyamine is a polyether amine. 5. A bonding resin according to any one of claims 1-4, wherein the lignin 30 and/or tannin solution is a solution of lignin and/or tannin in ammonia and/or organic base. 6. A bonding resin according to any one of claims 1-5, wherein the weight ratio of the lignin and/or tannin to polyamine, calculated on the basis of 35 dry solids, is from 2:1 to 5:1. 7. A bonding resin according to any one of claims 1-6, wherein the weight ratio of the epoxy-based crosslinker to the lignin and/or tannin is in the range of from 1:100 to 10:1, preferably from 2:100 to 1:1, calculated on the basis of dry solids. 5 8. A bonding resin according to any one of claims 1-7, wherein the epoxy- based crosslinker is selected from glycerol diglycidyl ether, polyglycerol polyglycidyl ether, glycerol triglycidyl ether, sorbitol polyglycidyl ether, alkoxylated glycerol polyglycidyl ether, trimethylolpropane triglycidyl 10 ether, trimethylolpropane diglycidyl ether, polyoxypropylene glycol diglycidylether, polyoxypropylene glycol triglycidyl ether, diglycidylether of cyclohexane dimethanol, resorcinol diglycidyl ether, isosorbide diglycidyl ether, pentaerythritol tetraglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether having 2-9 ethylene 15 glycol units, propylene glycol diglycidyl ether having 1-5 propylene glycol units, diglycidyl-, triglycidyl- or polyglycidyl- ether of a carbohydrate, diglycidyl-, triglycidyl- or polyglycidyl-ester of a carbohydrate, diglycidyl- ether or diglycidyl ester of salicylic acid, vanillic acid, or 4- hydroxybenzoic acid, an epoxidized or glycidyl substituted plant-based 20 phenolic compound or epoxidized plant-based oil, tris(4-hydroxyphenyl) methane triglycidyl ether, N,N-bis(2,3-epoxypropyl)aniline, p-(2,3- epoxypropoxy-N,N-bis(2,3-epoxypropyl)aniline, diglycidyl ether of bis- hydroxymethylfuran, and/or diglycidyl ether of terminal diol having a linear carbon chain of 3-6 carbon atoms. 25 9. Fibrous insulation product comprising a bonding resin according to any one of claims 1-8 and fibrous material. 10. A fibrous insulation product according to claim 9, wherein the fibrous 30 material is selected from wood fibers, glass fibers, mineral fibers, aramid fibers, ceramic fibers, metal fibers, carbon fibers, polyimide fibers, polyester fibers, rayon fibers and cellulose fibers. 11. A fibrous insulation product according to claim 10, wherein the fibrous 35 material is selected from glass fibers or mineral fibers. 12. Wood fiber insulation, laminate, wood product such as plywood, oriented strandboard (OSB), laminated veneer lumber (LVL), medium density fiberboard (MDF), high density fiberboard (HDF), parquet flooring, curved plywood, veneered particleboards, veneered MDF or particle 5 board manufactured using the bonding resin according to any one of claims 1-8.