BE1030513B1 - Glue for plates - Google Patents

Abstract

A plate comprising cellulosic materials, and an adhesive that connects these cellulosic materials together, wherein the adhesive is a glue based on amines, carbohydrates and additives, method for making such plates and an adhesive for such plates.

Description

1 BE2022/5351

Glue for plates

This invention concerns a board comprising cellulosic materials, such as vegetable fibers, and a cured adhesive that connects these cellulosic materials together. This invention also concerns a method for making such a plate, an adhesive for such plates and a method for manufacturing such adhesives.

This invention relates to plates comprising cellulosic materials.

These cellulosic materials can include one or more of the following materials: wood fibers, wood chips, wood layers, flax fibers, bamboo fibers, hemp fibers, wood waste from, among other things, the recycling of wood fiber boards, etc. These cellulosic materials can therefore be, for example, lignocellulosic materials. The plates are preferably fibreboards. The plants can be wood fiber boards, such as MDF Medium Density Fiberboard and HDF -High Density Fiberboard, other wood-based boards such as OSB (oriented strand board), plywood boards, etc. and non-wood-based fiber boards, such as flax boards, bamboo boards, hemp boards, etc. These plates may or may not be partially or completely formed from recycled material, such as recycled lignocellulosic material. For example, the cellulosic materials may include recycled materials from the recycling of, for example, wood fiber boards or panels comprising such wood fiber boards. For example, wood fiber boards can contain particles of recycled wood fiber boards.

The most common adhesive used in producing such boards is an aminoplast polymer, produced via a polycondensation reaction from urea and formaldehyde to form a urea-formaldehyde resin (UF resin). Optionally, melamine is added and a melamine urea formaldehyde resin (MUF resin) is obtained, or melamine and phenol are added (MUPF resins: melamine urea phenol formaldehyde). The major advantages of such adhesives are their low cost - due to the use of commonly available and cheap raw materials in their preparation -; and their high reactivity. Such adhesives can be damaged during and after polymerization under the influence of

2 BE2022/5351 temperature, moisture, or pH change, emitting formaldehyde. More and more efforts are being made to limit formaldehyde emissions from panels or even reduce them to zero.

Therefore, formaldehyde-free adhesives were and are being sought for producing the above-mentioned plates.

Bio-based adhesives for panels already exist, but the production of panels using these adhesives is less simple. Disadvantages include too low reactivity, uncontrolled/undesirable prepolymerization, limited adhesive power, poor wetting properties, compared to current aminoplast adhesives containing formaldehyde. Examples of bio-based adhesives are adhesives based on lignin, plant flour such as soy flour, or sugars.

This invention relates to an adhesive based on amines and carbohydrates, so that the cured adhesive present in the board includes Maillard reaction products resulting from the Maillard reaction between these amines and carbohydrates. The present invention primarily aims to optimize such adhesives, and plates comprising such adhesives.

The invention concerns a board comprising cellulosic materials, such as vegetable fibers, and a cured adhesive that connects these cellulosic materials together, wherein the cured adhesive originates from an adhesive based on amines and carbohydrates and the cured adhesive comprises Maillard reaction products originating from the Maillard reaction between these amines and carbohydrates, where the glue further contains additives to control the Maillard reaction. To form this plate, use is made of an adhesive based on amines and carbohydrates, including additives, whereby this adhesive has not yet or at least not fully hardened. During the formation of the plate, this glue will harden (further) to create a hardened glue that connects the cellulosic materials together. A hardened glue here indicates that the glue has undergone hardening during the formation of the panel, is sufficiently dry and sufficiently connects the cellulosic materials to each other to achieve the desired panel. This does not necessarily mean that the glue

3 BE2022/5351 has fully hardened. A hardened glue 1s here may or may not be a fully hardened glue.

With the mentioned boards, such as fiber boards, OSB boards, plywood boards, etc., heat is generated and/or added during production, for example during the pressing of these boards. The Maillard reaction is generated with the help of heat, allowing the glue used to harden further. A cured adhesive derived from an adhesive based on amines and carbohydrates here refers to the adhesive that is formed after curing of the adhesive used to form the plates.

The glue used to form this plate is based on the aforementioned amines, carbohydrates and additives. This means that when the glue is formed, these amines, carbohydrates and additives are provided. Percentages, quantities, ratios of these amines, carbohydrates and additives are always expressed here on the basis of the dry matter quantities that were provided for forming the adhesive. This is because when forming the glue it is possible that these amines and carbohydrates will already (partially) react with each other prior to using the glue to form the plates. Quantities of cellulosic materials are preferably expressed in dry substance of cellulosic materials, i.e. dry cellulosic materials, for example dry wood.

With the help of the additives, the Maillard reaction is controlled in a targeted manner, preferably during the formation of the plates, so that the desired Maillard reaction products are formed and/or the desired reaction speed is achieved, which improves the properties of the cured adhesive and therefore also the properties of the formed plate are as optimal as possible. For example, the additives can increase the reactivity of the adhesive and/or prevent unwanted prepolymerization and/or increase the adhesive strength of the cured adhesive. The result is a plate with the desired tensile strength, bending strength, E-modulus, etc. The additives therefore provide a better adhesive. Using this adhesive, one can opt to produce panels with better properties, compared to panels manufactured with existing adhesives based on carbohydrates and amines. However, one can also opt to use less glue than with boards made with existing glues based on carbohydrates and amines, in order to obtain similar properties. Using the additives mentioned, one can also opt to increase the amine content in the glue

4 BE2022/5351. Good results are achieved when the weight percentage of amines on the total weight of amines and carbohydrates is at least 20. One can, for example, opt to use fewer amines and therefore opt for a weight percentage of amines on the total weight of amines and carbohydrates of a maximum of 20 or a maximum of 15 and this in order to obtain similar properties as with plates manufactured with existing adhesives on based on carbohydrates and amines.

The Maillard reaction is the collective name for a complex series of chemical reactions that occur between reducing sugars and amines. The carbohydrates and amines form Maillard reactants here. The additives mentioned may or may not be consumed in the Maillard reaction, and may or may not therefore be part of the Maillard reactants. One or more types of additives can be used.

Amines here refer to chemical compounds that contain at least one amine atomic group and are therefore a source of amines. The weight percentage of the sum of dry matter amines and dry matter carbohydrates, which are used to form the adhesive, on the dry matter of cellulosic materials, is for example between 2 and 20, preferably between 3 and 15, even more preferably between 4 and 10. We are talking here about dry matter amines and dry matter carbohydrates, which are used to form the glue, and this is because when the glue is formed, i.e. during the mixing of the ingredients of the glue, these ingredients are already can react with each other, for example forming water, which changes the dry matter content. The above quantities are also determined by the type of plate. Bee

MDF or HDF or OSB, this weight percentage can be between 5 and 10, and can therefore be, for example, 6, 7, 8 or 9.

For example, the amines make up between 15 and 40 percent by weight of the total weight of amines and carbohydrates, preferably between 20 and 30 percent by weight. The carbohydrates then make up between 60 and 85 percent by weight of the total weight of amines and carbohydrates, preferably between 70 and 80 percent by weight. The amines may include, for example, diamines, such as hexamethylenediamine (HDMA), or amides comprising amine groups. For example, the weight percent of amines on the total weight of amines and carbohydrates can be 22, 23, 24, 25, 26, 27 or 28.

The carbohydrates have been and/or are being converted into reducing sugars. For the

Maillard reaction requires reducing sugars. For example, sucrose can be used, which is converted into glucose and fructose, for example. Sucrose is a common sugar and is a bio-based and inexpensive carbohydrate source. One can also start from invert sugar. The carbohydrates used can also include only glucose or only fructose.

An adhesive based on carbohydrates and amines refers to an adhesive whose dry matter consists largely of carbohydrates and amines, for example of at least 50% by weight of carbohydrates and amines on the total weight of the dry matter, preferably at least 70% by weight and even more. preferably at least 80 percent by weight and most preferably at least 90 percent by weight. Preferably, the additives mentioned constitute at most 20% by weight, preferably at most 10% by weight and most preferably at most 5% by weight of the total weight of dry matter.

During the making of the glue used to form the plate, the different ingredients of the glue are combined. This glue is then used to bond the cellulosic materials of the board to form the board.

The above-mentioned plates are usually formed using pressing, where heat is created and/or added during this pressing. The Maillard reaction takes place with the help of this heat. It is possible that prior to pressing, i.e. during the formation of the adhesive, the Maillard reaction has already partially taken place, and the adhesive, when gluing the cellulosic materials, has already

Maillard reaction products. For example, heat can be added while combining the ingredients of the glue to allow the Maillard reaction to take place. This has the advantage that the glue already contains some Maillard reaction products when gluing, so the pressing time can be shortened and/or the reactivity of the glue is higher. For example, one can proceed as follows: a prereact is first made comprising the carbohydrates and part of the amines. This prereact is heated (and/or the carbohydrates and/or the said portion of the amines are heated prior to combining to form the prereact). In this way, the Maillard reaction takes place in the formation of this prereact and has it

6 BE2022/5351 already prereacts a number of Maillard reaction products. The rest of the amines are then added to form the glue, which is then used for gluing the cellulosic materials. This prereact may already include some or all of the additives. These additives can be added at the beginning of the formation of the prereact, but also added during the formation of the prereact, and also added after the formation of the prereact. When the additives are added can also depend on the type of additive. For the formation of the prereact, for example, between 15 and 40 percent by weight of the amines can be provided, for example between 20 and 30 percent by weight, such that there are still sufficient amines present in the glue formed that have not yet reacted.

These cellulosic materials are preferably lignocellulosic materials.

The vegetable fibers are, for example, wood fibers. These wood fibers may or may not be present in the form of wood fiber bundles.

Preferably, only one first type of adhesive is used to form the plates, namely adhesives based on said carbohydrates and amines, but the plates can also comprise other types of adhesives. For example, use can be made of an adhesive mixture comprising the first type of adhesive and one or more other types of adhesives, and/or the plate can be multi-layered, whereby the first type of adhesive is used for one layer and a different type is used for another layer. glue is used.

Examples of other adhesives include conventional UF adhesives, MUF adhesives, MUPF adhesives, pMDI adhesives, polyurethane adhesives, polyvinyl butyral adhesives, polyacrylate adhesives, etc. Polyurethane adhesives can, for example, be used to increase water resistance and/or flexibility. It is also possible for a plate to be formed with different glues from the first type of glue. For example, the plate can be multi-layered in which different glues, but for example all glues based on the mentioned carbohydrates and amines, are used for the different layers.

These latter different adhesives can differ in all kinds of areas.

Below is a non-exhaustive list of possible differences, whereby these differences can be combined with each other as long as this is not contradictory: dry matter content, additives -which and amounts-, carbohydrates -which and

7 BE2022/5351 quantities, amines -which ones and quantities-, solvent used (water or solvent), etc.

Preferably the additives comprise bases. With the help of bases, the pH is controlled during the Maillard reaction to ensure that the desired Maillard reaction products are formed. Surprisingly, it was found that K:CO; is a very suitable base to use as an additive. KCO: is a base that ensures a faster start of the Maillard reaction, but does not cause unwanted prepolymerization of the adhesive. Preferably the bases also comprise K5CO3, and even more preferably the bases comprise only K5CO3. Prepolymerization refers to the polymerization of the glue prior to, for example, forming, for example pressing, the plate. The addition of K5CO: does not cause an unwanted increase in viscosity of the adhesive. Other bases, for example the strong bases

NaOH and KOH can also be used. The bases can also be Na:CO; and/or

Na,HPO4 and, for example, only include one of these mentioned bases.

NaOH and KOH can cause unwanted prepolymerization and thus result in plates with reduced technical properties, making them less suitable. It is also possible to use two or more different bases.

Furthermore preferably, the plate comprises one or more layers, wherein at least one said layer comprises said cellulosic materials and said cured adhesive, whereby preferably in this layer, the weight percentage of bases on cellulosic materials lies between 0.1 and 1, still more preferably between 0.15 and 0.25. For example, the weight percentage of KCO: on cellulosic materials can be between 0.1 and 1, preferably between 0.15 and 0.25. This weight percentage here refers to the amount of dry matter bases, for example the amount of K5CO3, that is added when forming the glue to the dry matter content of the cellulosic materials used to form the plate.

Also further preferred is the ratio KaCO; on the total dry weight of amines and carbohydrates between 0.01 and 0.2, preferably between 0.02 and 0.1. This ratio refers to the ingredients used in forming the glue. For

8 BE2022/5351 before forming the adhesive, K5CO: is preferably introduced into an aqueous solution of, for example, at least 40 percent by weight K:CO; and this to promote addition and good mixing. For example, an aqueous solution with 50% by weight K:CO; or 60% by weight K,CO; are used to form the adhesive.

In a preferred embodiment, the additives comprise salts of a hypochlorous acid. Salts of a hypochlorous acid promote the formation of Strecker degradation products during the Maillard reaction, allowing plates with higher stiffness to be obtained and/or the same stiffness with less glue. Surprisingly, it was found that sodium hypochlorite (NaOCI) in particular has a positive influence. Thus, the salts of a hypochlorous acid preferably include and are even more preferred

NaOCl. Other examples of possible salts of hypochlorous acid are potassium hypochlorite and calcium hypochlorite. It is also possible to use two or more different named salts.

Furthermore, the plate preferably comprises one or more layers, wherein at least one said layer comprises said cellulosic materials and said cured glue, whereby preferably in this layer, the weight percentage of salts of a hypochlorous acid on cellulosic materials is between 0.1 and 1. , even more preferably between 0.1 and 0.2. For example, the weight percentage of NaOCl on cellulosic materials can be between 0.1 and 1, preferably between 0.1 and 0.2. This weight percentage here refers to the amount of dry matter salts of a hypochlorous acid, for example the amount of NaOCl, that was added when forming the glue to the dry matter content of the cellulosic materials used in forming the plate.

Also preferably, the ratio of NaOCl to the total dry weight of amines and carbohydrates is between 0.01 and 0.2, preferably between 0.02 and 0.1. This ratio refers to the ingredients used in forming the glue. To form the adhesive, NaOCl is preferably introduced into an aqueous solution of, for example, at least 40% by weight NaOCl, to allow it to be added and properly

9 BE2022/5351 to promote mixing. For example, an aqueous solution containing 50% by weight NaOCI or 60% by weight NaOCI can be used to form the adhesive.

In a very preferred embodiment, the additives comprise crosslinkers, and these crosslinkers preferably comprise intermediate products resulting from the Maillard reaction between amines and carbohydrates. To form the glue, mentioned amines that have not yet reacted with a reducing sugar, mentioned carbohydrates, and additionally mentioned crosslinkers will be provided here. With the help of these crosslinkers, the reactivity and thus the quality of the adhesive is increased. Since the crosslinkers are consumed in the Maillard reaction, these crosslinkers are considered Maillard reactants. By also actively adding the intermediate products mentioned, and therefore not waiting until these intermediate products are formed during the Maillard reaction, it is ensured that various reaction paths of the Maillard reaction are already present at the start.

Furthermore preferably, the crosslinkers are selected from the group comprising: α-hydroxyaldehydes, glyceraldehyde and α-dicarbonyls. The best results are achieved with a-dicarbonyls, as they have the most positive influence on the reactivity of the adhesive. These α-dicarbonyls can be, for example, dialdehyde and/or glyoxal and/or methylglyoxal and/or deoxyosones. α-dicarbonyls react with the amines present to form AGE products (Advanced Glycation End Product), which can be classified as melanoidins if the molecular weight is higher than 10 kilodaltons.

If the crosslinkers mentioned are intermediate products resulting from the Maillard reaction between amines and carbohydrates, these intermediate products can influence the viscosity of the glue used to form the plates. It is therefore preferable to take this into account when forming the glue, i.e. when mixing the different ingredients. This allows you to choose when to add these crosslinkers and/or how the mixing takes place. These crosslinkers can thus be added while forming the above-mentioned prereact. These crosslinkers can also be added after forming the prereact, but prior to

10 BE2022/5351 adding the remaining amines to the prereact. These crosslinkers can also be added last, i.e. after adding the remaining amines to the prereact. Preferably, the crosslinkers are added prior to adding the remaining amines. It is also possible to dose the crosslinkers separately on the cellulosic materials.

Furthermore, the plate preferably comprises one or more layers, wherein at least one said layer comprises said cellulosic materials and said cured adhesive, whereby preferably in this layer the weight percentage of said crosslinkers on cellulosic materials is between 0.02 and 0.16. preferably between 0.04 and 0.08. This weight percentage here refers to the amount of dry matter crosslinkers, for example the amount of o-dicarbonyls, being for example dialdehyde and/or glyoxal and/or methylglyoxal and/or deoxyosones, that were added when forming the glue based on the dry matter content of the cellulosic materials.

Also preferably, the ratio of α-dicarbonyls, such as the ratio of dialdehyde and/or glyoxal and/or methylglyoxal and/or deoxyosones, to the total dry weight of amines and carbohydrates is between 0.01 and 0.20, preferably between 0.01 and 0.20. between 0.02 and 0.1. This ratio refers to the ingredients used in forming the glue. To form the adhesive, glyoxal, or another named o-dicarbonyl, is preferably introduced into an aqueous solution of, for example, at least 30 percent by weight glyoxal, or another named a-dicarbonyl, to promote addition and good mixing. For example, an aqueous solution containing 40 percent glyoxal or 50 percent glyoxal by weight can be used to form the adhesive.

In a specific embodiment, the additives comprise metal-comprising components, for example metal oxides and/or metal hydroxides and/or chelating metal salts. With the help of these metal-comprising components, the polymerization is strengthened and/or accelerated under the influence of heat, resulting in very strong plates. The weight percentages of said metal-containing components on cellulosic materials is, for example, between 0.01 and 0.2, preferably

11 BE2022/5351 between 0.025 and 0.1. Additionally, addition of Ca(OH)2, Mg(OH) or

CaCl: ensures a hardening of formed polymers after pressing the plate, which contributes to the strength and strength of the plates.

A very preferred aspect according to the invention is a plate, optionally as described in one or more of the embodiments described above, comprising cellulosic materials, such as vegetable fibers, and a cured adhesive that connects these cellulosic materials, wherein the cured adhesive comes from is an adhesive based on amines and carbohydrates and the adhesive comprises Maillard reaction products originating from the Maillard reaction between these amines and carbohydrates, whereby at least part of the amines is selected from the group comprising: highly branched polyamides or chain-shaped amines, and wherein preferably, at least some of the amines are highly branched polyamides. The chain-shaped amines may include, for example, triethylenetetramine (TETA).

In prior art plates, only HDMA is usually used as a source of amines. With HDMA it is possible to produce plates of a certain quality. However, the production of HDMA has a high carbon footprint because fossil raw materials are needed to produce HDMA industrially. In addition, HDMA is corrosive. TETA is a good alternative to HDMA, but the production of TETA is usually done with fossil raw materials.

Surprisingly, it was found that for adhesives based on amines and carbohydrates, highly branched polyamides can be used as an amine source. It is therefore possible that at least some of the amines, and preferably at least 50% of the amines, even more preferably at least 70% by weight of the amines, and most preferably at least 90% by weight of the amines, are highly branched polyamides.

The remaining amines are, for example, HDMA or TETA or a combination of these

HDMA and TETA. It is also possible that all amines are highly branched polyamides.

It is also surprising that such glues have a particularly good adhesive power.

Moreover, the production of plates using this glue can be done in a similar way to the production of such plates with conventional urea

12 BE2022/5351 formaldehyde adhesives (UF adhesives). One can therefore switch to an adhesive based on carbohydrates and amines containing highly branched polyamides, without changing the production process too much. These plates are obtained, for example, by providing the cellulosic materials with the glue and then pressing the cellulosic materials provided with glue into plate-shaped material, whereby this plate-shaped material is, for example, sawn into plates or already forms a plate with the desired dimensions. Pressing is preferably done at an elevated temperature, which can reach more than 200°C.

Even more surprisingly, it was found that boards comprising cellulosic materials bonded together with a carbohydrate-based adhesive and amines comprising highly branched polyamides can exhibit better technical characteristics than such boards comprising such adhesives in which the amines only contain

include HDMA. This allows higher stiffness (N/mm?) and transverse tensile strength (N/mm?) and/or higher water resistance.

Highly branched polyamides are highly branched three-dimensional macromolecules. High/strong branching indicates that the polyamides are not linear and also indicates that there are a significant number of branches. This means that there are more than 3, preferably more than 5 and even more preferably more than 10 branches present in the polyamide macromolecule.

Such polyamides can be bio-based. The highly branched polyamides can, for example, be based on polycondensed amino acids, whereby these amino acids are produced, for example, with the help of bacteria. Bacteria, such as Corynebacterium (gram positive) or Escherichia coli (gram negative), can chemically convert amino acids via fermentation into, for example, mainly lysine and some glutamine. Since the amines of the glue here include highly branched polyamides, and the glue also largely consists of sugars, this glue also contributes to the durability of the panels mentioned. In addition, this glue does not have to contain formaldehyde and preferably does not contain formaldehyde, so that there is no problem with any formaldehyde emissions. When the highly branched polyamides are based on polycondensed amino acids, it is not necessary that they are based only on one type of amino acid. When it is used

13 BE2022/5351 For example, from bacteria that mainly produce lysine and a small part of other amino acids such as glutamine, both the lysine and the glutamine can be used for the production of the highly branched polyamides, making an additional purification step of the amino acids unnecessary and the production of the highly branched polyamides can take place in an ecological manner.

Preferably, only one first type of adhesive is used to form the plates, namely adhesives based on said carbohydrates and amines, but the plates can also comprise other types of adhesives. For example, use can be made of an adhesive mixture comprising the first type of adhesive and one or more other types of adhesives, and/or the plate can be multi-layered, whereby the first type of adhesive is used for one layer and a different type is used for another layer. glue is used.

Examples of other adhesives include conventional UF adhesives, MUF adhesives, MUPF adhesives, pMDI adhesives, polyurethane adhesives, polyvinyl butyral adhesives, polyacrylate adhesives, etc. Polyurethane adhesives can, for example, be used to increase water resistance and/or flexibility. It is also possible for a plate to be formed with different glues from the first type of glue. For example, the plate can be multi-layered, with different adhesives, but for example all adhesives based on carbohydrates and amines, being used for the different layers. These latter different adhesives can differ in all kinds of areas. Below is a non-exhaustive list of possible differences, whereby these differences can be combined with each other as long as this is not contradictory: dry matter content, the amount of highly branched polyamides, the average molecular weight of the highly branched polyamides, amines - which ones and amounts -, carbohydrates -which and quantities-, additives -which and quantities-, solvent -water or solvent-.

In a preferred embodiment, the said highly branched polyamides are obtained by polycondensation of amino acids, wherein these amino acids are preferably selected from the group containing arginine, glutamine, asparagine and lysine. The highly branched polyamides are obtained here via peptide bonds, with no preference given to functional groups of the amino acids. This results in a complex network of polyamides that can serve well as an amine for the Maillard

14 BE2022/5351 response. The highly branched polyamides are obtained, for example, from the polycondensation of mainly lysine. Lysine is a basic amino acid that is cationic in a neutral medium. Lysine is, for example, obtained via fermentation using bacteria, such as Corynebacterium or Escherichia coli bacteria. During the production of lysine, smaller amounts of other amino acids such as glutamine can also be formed. By choosing the bacteria, nutrients and fermentation conditions, the desired amino acids can be specifically formed. Multiple carbohydrate sources can be used for this fermentation, such as sucrose, glucose, cellulose, hemicellulose or lignin. Mixtures of ammonium salts, such as ammonium sulphate or diammonium phosphate, are often used as an ammonium source for fermentation. Ammonium sulphate can be obtained as a by-product during manure processing or after stripping ammonia-containing gases. In other words, the production of amino acids, such as lysine, can be completely or largely based on bio-based raw materials and/or waste materials.

In a specific embodiment, the highly branched polyamides comprise a first group of highly branched polyamides with a molecular weight between 500 and 100,000 g/mol, preferably between 5000 and 50,000 g/mol and even more preferably between 10,000 and 25,000 g/mol. mol, wherein the first group of highly branched polyamides preferably constitutes at least 60 percent by weight, even more preferably at least 65 percent by weight, even more preferably at least 70 percent by weight, even more preferably at least 75 percent by weight and most preferably at least 80 percent by weight of the high branched polyamides. The reactivity of the highly branched polyamides is optimal if the molecular weight is higher than 5000 g/mol and the gluing can be done very well when the molecular weight is lower than 50000 g/mol. This also allows good production of the plates.

In a preferred embodiment, the plate comprises one or more layers, wherein at least one said layer comprises said cellulosic materials and said glue, whereby preferably in this layer the weight percentage of highly branched polyamides on cellulosic materials is between 0.5 and 3, still more preferably between 1 and 2. These weight percentages are the cellulosic

BE2022/5351 materials preferably dried cellulosic materials such as dry wood containing no residual moisture. Here, only 1 layer, or only a number of layers, can comprise cellulosic materials and a mentioned glue, while other layers then comprise, for example, a different glue. Preferably, all said layers comprise cellulosic materials and a said adhesive based on carbohydrates and amines.

In a specific embodiment, the plate comprises three or more layers, being two outermost covering layers, and one or more central layers, wherein at least one central layer comprises said cellulosic materials and said adhesive, and wherein the covering layers each comprise cellulosic materials and an adhesive on based on carbohydrates and amines comprising highly branched polyamides, wherein the weight ratio of highly branched polyamides to cellulosic materials in the covering layers is higher than the weight ratio of highly branched polyamides to cellulosic materials in the latter central layer. For example, the weight percentage of highly branched polyamides on cellulosic materials in the covering layers can be between 2 and 3 and the weight percentage of highly branched polyamides on cellulosic materials in a mentioned central layer can be between 0.5 and 2. The glue used for the covering layers can be the same glue as the glue used for the one or more central layers mentioned. However, it is possible that different glues are used for the different layers, but for example always glues based on carbohydrates and amines. These plates can be manufactured using, for example, press plates at temperatures between 170°C and 245°C, at a pressure between 2 and 5 N/mm? and this for at least 3 seconds, preferably at least 5 seconds, per mm of sheet thickness. The composition of the cellulosic materials can differ per layer. The one or more central layers and/or the covering layers can, for example, comprise recycled cellulosic materials.

In a special embodiment, the highly branched polyamides comprise a first group of highly branched polyamides and a second group of highly branched polyamides, wherein the average molecular weight of the first group of highly branched polyamides

16 BE2022/5351 is at least 3 times higher, preferably at least 5 times higher than the average molecular weight of the second group of highly branched polyamides and/or where the average molecular weight of the first group of highly branched polyamides is at most 15 times higher, preferably is at most 10 times higher than the average molecular weight of the second group of highly branched polyamides. The first group of highly branched polyamides form the high molecular weight highly branched polyamides and the second group of highly branched polyamides form the low molecular weight highly branched polyamides. The combination of high molecular weight highly branched polyamides and low molecular weight highly branched polyamides improves the performance of the adhesive, in both reactivity and technical characteristics. The mentioned high molecular weight highly branched polyamides have, for example, an average molecular weight of at least 5000 and preferably at least 10000 g/mol, for example an average molecular weight between 5000 and 50000 g/mol, preferably between 10000 and 25000 g/mol. The low molecular weight polyamides then, for example, have an average molecular weight between 500 and 5000 g/mol.

With the help of this combination, the further polymerization of the adhesive during pressing of the plate is accelerated. We are talking here about groups of highly branched polyamides with an average molecular weight. Not all macromolecules from the same group have the same molecular weight. This is, for example, the result of the production of these highly branched polyamides. In the polycondensation of amino acids, not all amino acids will obtain the same reactions, i.e. the same branches, resulting in the obtained highly branched polyamides having different molecular weights. The highly branched polyamides from the same group are obtained, for example, by the same production, where, for example, for the first group of highly branched polyamides the polycondensation takes place for a longer time than for the second group of highly branched polyamides, such that the average molecular weight of the first group highly branched polyamides is higher than the average molecular weight of the second group of highly branched polyamides.

Furthermore, preferably the second group of highly branched polyamides comprises between 5 and 30 weight percent of the total weight of the highly branched polyamides, preferably between 10 and 20 weight percent.

17 BE2022/5351

In a very preferred embodiment, the adhesive comprises amine cross-linkers, whereby preferably these amine cross-linkers are selected from the group comprising polyketones, polyesters, isocyanate dispersions, epoxides, glyoxal and other dialdehydes. These amine cross-linkers provide additional cross-links between the highly branched polyamides during the forming of the plates, which ensures good properties of the formed plate.

These amine cross-linkers, if they include, for example, glyoxal and/or dialdehydes, are also part of the cross-linkers as described above. The amine cross-linkers can therefore not only provide additional crosslinks between the highly branched polyamides, but also additional crosslinks in the Maillard reaction.

The amine cross-linkers mentioned are or include, for example, polyesters, whereby these polyesters are preferably dispersed and/or unsaturated polyesters. For example, these unsaturated polyesters are highly branched, making them easily soluble and not adversely affecting the viscosity of the glue used to form the plates. During the production of the plates, where pressing is used, the acidity of the polyesters is preferably brought or stabilized towards the acidity of the polyamides, so that no acid/base reactions, i.e. undesirable prepolymerization, take place prior to pressing. .

The adhesive may comprise one or more types of amine cross-linkers. During the pressing of the plates, these amine cross-linkers ensure better and faster bonding between the cellulosic materials, so that the resulting plate has the necessary strength and strength and the connection between the cellulosic materials does not break undesirably.

In addition, with the help of these amine cross-linkers, the pressing time can be further shortened and the technical characteristics of the end product, such as the HDF, MDF or

OSB. The technical characteristics include bending strength, tensile strength, compressive strength and water resistance.

The amine cross-linkers mentioned are or include, for example, epoxides. Excellent results are achieved using epoxides, such as di-epoxides or tri-epoxides.

These epoxides can, for example, be produced via bio-based routes

18 BE2022/5351 lignin or aniline, such as glycerol diglycedyl ether, and/or ethylene glycol diglycedyl ether.

Epoxides are known to react with amines. For example, tertiary amines are used as a hardener component in epoxy resins. However, it is exceptional that highly branched polyamides can be brought into contact with epoxides without unwanted prepolymerization after gluing the cellulosic material and prior to pressing the sheet. Preferably, an overstochiometric amount of highly branched polyamides is contacted with epoxides. With highly branched polyamides, the epoxides only become active when pressure and temperature are added in the press. The addition of epoxides to highly branched polyamides hardly increases the viscosity of the adhesive. This does not make pressing the plate difficult and the bond between the cellulosic materials can be achieved very well. These amine cross-linkers can already be pre-mixed with the highly branched polyamides of the adhesive used and stored this way. However, the amine cross-linkers can also be combined with the highly branched polyamides of the adhesive used shortly before gluing. The glue used is then, for example, two-part, comprising a first part comprising the highly branched polyamides and a second part comprising amine cross-linkers, whereby these two parts are only joined before gluing or during gluing of the cellulosic materials. The amine cross-linkers mentioned can also be regarded as separate ingredients, regardless of the glue used in the production of plates, where the glue used, together with the amine cross-linkers, forms the cured glue based on highly branched polyamides present in the plate.

Furthermore, the weight ratio of amine cross-linkers to the highly branched polyamides is preferably between 0.02 and 0.15. For example, between 3 and 6 weight percent epoxides, for example 4 or 5 weight percent epoxides, may be present on highly branched polyamides. A higher proportion of amine cross-linkers contributes to the water resistance of the adhesive and therefore of the panel containing this adhesive. The content of amine cross-linkers should also not be too high, as this can cause prepolymerization of the adhesive prior to pressing the plate. This weight ratio ensures optimal technical characteristics, more specifically a

19 BE2022/5351 better tensile strength, bending strength and compressive strength and better water resistance.

Such panels are therefore not only suitable for applications in dry indoor conditions, but also extremely suitable in more humid areas, such as damp indoor areas such as bathrooms.

The invention also relates to an adhesive for connecting cellulosic materials, such as vegetable fibres, into plates, wherein the adhesive is based on amines and carbohydrates, wherein the adhesive comprises additives for controlling the Maillard reaction. This glue is the glue used to produce plates as described above. The advantages and embodiments of the plate shown above with regard to the glue also apply to this glue.

Surprisingly enough, it was found that such an adhesive is extremely suitable for bonding cellulosic materials, such as wood fibers or other vegetable fibers, wood layers and wood chips, together to form panels by pressing. The amines and carbohydrates form Maillard reactants that react with each other during the reaction

Maillard reaction to form Maillard reaction products.

After curing, for example by pressing, the adhesive contains Maillard reaction products from the Maillard reaction between these amines and carbohydrates. The additives mentioned steer the Maillard reaction in the desired direction. The glue is based on the aforementioned amines, carbohydrates and additives. This means that when the glue is formed, these amines, carbohydrates and additives are provided. Percentages, quantities, ratios of these amines, carbohydrates and additives are always expressed here on the basis of the dry matter quantities that were provided for forming the adhesive. This is because when forming the glue it is possible that these amines and carbohydrates will already (partially) react with each other prior to using the glue to form the plates.

The additives can, for example, increase the reactivity of the glue and/or prevent unwanted prepolymerization and/or increase the adhesive strength of the cured glue. The additives therefore provide a better adhesive.

20 BE2022/5351

The Maillard reaction is the collective name for a complex series of chemical reactions that occur between reducing sugars and amines. The carbohydrates and amines form Maillard reactants here. Said additives may or may not be consumed in

Maillard reaction, and may or may not be part of the Maillard reactants. One or more types of additives can be used.

Amines here refer to chemical compounds that contain at least one amine atomic group and are therefore a source of amines.

For example, the amines make up between 15 and 40 percent by weight of the total weight of amines and carbohydrates, preferably between 20 and 30 percent by weight. The carbohydrates then make up between 60 and 85 percent by weight of the total weight of amines and carbohydrates, preferably between 70 and 80 percent by weight. The amines can, for example, include diamines such as hexamethylenediamine (HDMA) and/or highly branched polyamides. For example, the amines make up 22, 23, 24, 25, 26, 27 or 28 percent by weight of the total weight of amines and carbohydrates.

The carbohydrates have been and/or are being converted into reducing sugars. For the

Maillard reaction requires reducing sugars. For example, sucrose can be used, which is converted into glucose and fructose. Sucrose is a common sugar and is a bio-based and inexpensive carbohydrate source. The carbohydrates can also be invert sugar. The carbohydrates can also include only glucose or only fructose.

Preferably the additives include bases for controlling pH. With the help of bases, the pH is controlled during the Maillard reaction to ensure that the desired Maillard reaction products are formed. Surprisingly, it was found that K:CO; is a very suitable base to use as an additive. K:CO; is a base that ensures a faster start of the Maillard reaction, but does not cause unwanted prepolymerization of the glue. Preferably, the bases also include

K;CO: and even more preferably the bases comprise only K:CO4. Prepolymerization refers to the polymerization of the glue prior to, for example, forming, for example pressing, the plate. The addition of K5CO: does not cause an unwanted increase in viscosity of the adhesive. Other bases, for example the strong bases NaOH and KOH, can also be used. The bases can also be Na2CO: and/or

Na:HPO4 and, for example, only include one of these mentioned bases.

21 BE2022/5351

NaOH and KOH can cause unwanted prepolymerization and thus result in plates with reduced technical properties, making them less suitable. It is also possible to use two or more different bases.

Furthermore, the bases preferably comprise between 1 and 20 percent by weight of the glue on a dry matter basis, even more preferably between 2 and 10 percent by weight and most preferably between 3 and 5 percent by weight.

In a preferred embodiment, the additives comprise salts of a hypochlorous acid. Salts of a hypochlorous acid promote the formation of Strecker degradation products during the Maillard reaction, allowing plates with a higher stiffness to be obtained and/or the same stiffness but with less glue. Surprisingly, it was found that sodium hypochlorite (NaOCI) in particular has a positive influence. Thus, the salts of a hypochlorous acid preferably include and more preferably NaOCl. Other possible salts of a hypochlorous acid are potassium hypochlorite and calcium hypochlorite.

Furthermore, preferably the salts of a hypochlorous acid constitute between 1 and 20 weight percent of the adhesive, even more preferably between 2 and 10 weight percent, most preferably between 3 and 4 weight percent.

In a particularly preferred embodiment, the additives comprise crosslinkers, and these crosslinkers are preferably intermediate products formed in the Maillard reaction between amines and carbohydrates. To form the glue, mentioned amines that have not yet reacted with a reducing sugar, mentioned carbohydrates, and additionally mentioned crosslinkers will be provided here. Using these crosslinkers increases the reactivity and thus the quality of the adhesive. Since the crosslinkers are consumed in the Maillard reaction, these crosslinkers are considered Maillard reactants. By also actively adding the intermediate products mentioned, i.e. the crosslinkers, and therefore not waiting for these intermediate products to be formed during the Maillard reaction, it is ensured that various reaction paths of the Maillard reaction are already present immediately at the start of using the adhesive. are.

22 BE2022/5351

Furthermore preferably, the crosslinkers are selected from the group comprising: α-hydroxyaldehydes, glyceraldehyde and α-dicarbonyls. The best results are achieved with a-dicarbonyls, as they have the most positive influence on the reactivity of the adhesive. These α-dicarbonyls can be, for example, dialdehyde and/or glyoxal and/or methylglyoxal and/or deoxyosones. α-dicarbonyls react with the amines present to form AGE products (Advanced Glycation End Product), which can be classified as melanoidins if the molecular weight is higher than 10 kilodaltons. The crosslinker can, for example, be glyoxal.

If the crosslinkers mentioned are intermediate products resulting from the Maillard reaction between amines and carbohydrates, these intermediate products can influence the viscosity of the glue used to form the plates. It is therefore preferable to take this into account when forming the glue, i.e. when mixing the different ingredients. This way you can choose when to add these intermediate products and/or how the mixing takes place. These intermediate products can thus be added during the formation of the above-mentioned prereact.

Furthermore, these crosslinkers preferably comprise between 0.3 and 3 percent by weight of the adhesive on a dry matter basis, even more preferably between 0.7 and 1.6 percent by weight. This weight percentage here refers to the amount of dry substance crosslinkers, for example the amount of α-dicarbonyls, being for example dialdehyde and/or glyoxal and/or methylglyoxal and/or deoxyosones, that were added when forming the glue.

Also preferably, the ratio of α-dicarbonyls, such as the ratio of dialdehyde and/or glyoxal and/or methylglyoxal and/or deoxyosones, to the total dry weight of amines and carbohydrates is between 0.01 and 0.20, preferably between 0.01 and 0.20. between 0.02 and 0.1. This ratio refers to the ingredients used in forming the glue. To form the glue, glyoxal, or another named a-dicarbonyl, is preferably introduced into an aqueous solution of, for example, at least 30 percent by weight glyoxal, or another named a-dicarbonyl, to promote addition and good mixing. So can an aqueous solution

23 BE2022/5351 with 40% by weight glyoxal or 50% by weight glyoxal are used to form the adhesive.

In a specific embodiment, the additives comprise metal-comprising components, for example metal oxides and/or metal hydroxides and/or chelating metal salts. The weight percentages of said metal-containing components on cellulosic materials are, for example, between 0.01 and 0.2, preferably between 0.025 and 0.1. Additionally, addition of Ca(OH), Mg(OH): or

CaCl: ensures a hardening of formed polymers after pressing the plate, which contributes to the strength and strength of the plates.

The invention also concerns an adhesive, optionally as shown above, for joining cellulosic materials, such as vegetable fibres, into plates, wherein the adhesive is based on amines and carbohydrates, wherein at least part of the amines is selected from the group comprising: highly branched polyamides or chain-shaped amides; and wherein the amines preferably comprise highly branched polyamides.

This glue is the glue used to manufacture plates comprising a hardened glue derived from a glue based on carbohydrates and amines, wherein the amines include highly branched polyamides and/or chain-shaped amides, as described above. The advantages and designs of these plates also apply to this glue. Surprisingly enough, it was found that such an adhesive is extremely suitable for bonding cellulosic materials, such as wood fibers or other vegetable fibers, wood layers and wood chips, together to form panels by pressing.

Preferably the amines comprise highly branched polyamides, wherein the highly branched polyamides constitute at least 50% by weight, preferably at least 70% by weight, more preferably 90% by weight of the amines. For example, all amines can be highly branched polyamides.

24 BE2022/5351

These highly branched polyamides are preferably obtained by polycondensation of amino acids, whereby these amino acids are preferably selected from the group containing arginine, glutamine, asparagine and lysine.

In a specific embodiment, the highly branched polyamides comprise a first group of highly branched polyamides with a molecular weight between 500 and 100,000 g/mol, preferably between 5000 and 50,000 g/mol and even more preferably between 10,000 and 25,000 g/mol. mol and the highly branched polyamides further preferably comprise a second group of highly branched polyamides, wherein the average molecular weight of the first group of highly branched polyamides is at least 3 times higher, preferably at least 5 times higher than the average molecular weight of the second group of highly branched polyamides and/or wherein the average molecular weight of the first group of highly branched polyamides is at most 15 times higher, preferably at most 10 times higher than the average molecular weight of the second group of highly branched polyamides and wherein further preferably, the second group of highly branched polyamides constitutes between 5 and 30 percent by weight of the total weight of the highly branched polyamides, preferably between 10 and 20 percent by weight.

In a preferred embodiment, the adhesive comprises amine cross-linkers, wherein preferably these amine cross-linkers are selected from the group comprising polyketones, polyesters, isocyanate dispersions, epoxides, glyoxal and other dialdehydes and wherein the weight ratio of amine cross-linkers is also preferably on the highly branched polyamides. between 0.02 and 0.15. These amine cross-linkers provide additional cross-links between the highly branched polyamides during the forming of the plates, which ensures good properties of the formed plate. These amine cross-linkers, if they include, for example, glyoxal and/or dialdehydes, are also part of the cross-linkers as described above. The amine cross-linkers can therefore not only provide additional crosslinks between the highly branched polyamides, but also additional crosslinks in the Maillard reaction. The amine cross-linkers are or include, for example, polyesters, whereby these polyesters are preferably dispersed and/or unsaturated polyesters. The amine cross-linkers are or include, for example, epoxides. Excellent

25 BE2022/5351 results are obtained using epoxides, such as di-epoxides or tri-epoxides.

These epoxides can, for example, be produced via bio-based routes from lignin or aniline, such as glycerol diglycedyl ether, and/or ethylene glycol diglycedyl ether.

With this adhesive, both for embodiments that do not contain or contain highly branched polyamides, the weight ratio of amines to the sum of amines and carbohydrates is preferably at most 0.4, and even more preferably at least 0.15. For example, the weight ratio of amines to the sum of amines and carbohydrates can be: 0.22 or 0.23 or 0.24 or 0.25 or 0.26 or 0.27 or 0.28.

The adhesive may include water as a solvent and/or may also be solvent-based. During the gluing of the cellulosic materials, the water causes the cellulosic materials to become wet and there is even a slight penetration of the cell wall. With the help of this glue, the cellulosic materials can be connected very well to each other due to the good contact between the glue and the cellulosic materials. Using water as a solvent, contact between the adhesive and the cellulosic materials is possible on almost the entire outer surface of the cellulosic materials.

The viscosity of the adhesive used for forming plates is preferably at most 20,000 mPa.s, even more preferably at most 2,000 mPa.s, at 20°C and 1.013 bar.

This invention also concerns a method for forming plates comprising cellulosic materials, such as vegetable fibres, wherein cellulosic materials are provided and a glue is applied to these cellulosic materials, after which these glued cellulosic materials are pressed into a plate-shaped material for thus forming. of plates, the adhesive being an adhesive as shown above. Using this method, a plate is obtained as described above. All advantages and embodiments described above also apply to this method. Surprisingly enough, pressing into plates can be done in a similar way to pressing glued cellulosic materials into plates, where the glue is a conventional UF glue.

26 BE2022/5351

The cellulosic materials, such as wood chips, wood layers, wood fibers or other vegetable fibers, are provided with glue, i.e. glued, by, for example, atomizing/spraying/pouring glue onto these cellulosic materials. The cellulosic materials can be placed in an air stream or in a mixing vessel in order to bond the cellulosic materials as homogeneously as possible by misting and/or mechanical friction. The glued cellulosic materials are then pressed together in, for example, a continuous press or a discontinuous press, under a certain pressure, for example a pressure between 2 and 6.

N/mm}, preferably between 2 and 4 N/mm), at a certain temperature, for example a temperature between 160°C and 245°C, preferably 200°C and 245°C, and for a certain time , for example at least 4 seconds per mm sheet thickness.

The glue will bond here with the cellulosic materials and harden, thus creating a sturdy panel. This adhesive can be one-part, where the adhesive is kept in its entirety and applied in its entirety to the cellulosic materials.

The adhesive can also be two-part or multi-part, where the adhesive comprises two or more different parts that are kept separately, where these parts are joined together prior to gluing and thus applied as one whole to the cellulosic materials, or where these parts are joined without prior joining. are applied to the cellulosic materials, either simultaneously or separately.

In a specific embodiment, where the plate comprises one or more layers, these layers are pressed together and at least one said layer comprises said cellulosic materials and said glue, wherein the weight ratio of glue to cellulosic materials in this layer is between 0.03 and 0.15, preferably between 0.04 and 0.1. The plate may, for example, consist of three or more layers, with outermost covering layers, and one or more central layers, wherein at least one central layer comprises the said cellulosic materials and the said glue, and wherein the covering layers each comprise cellulosic materials and an adhesive as above. is shown, where the weight ratio of glue to cellulosic materials in the covering layers is higher than the weight ratio of glue to cellulosic materials in the latter central layer.

27 BE2022/5351

In a specific embodiment the adhesive comprises said crosslinkers and/or amine crosslinkers and/or said crosslinkers and/or amine crosslinkers are applied to the cellulosic materials. If the adhesive itself does not contain the crosslinkers and/or amine crosslinkers mentioned, the application of crosslinkers and/or amine crosslinkers to the cellulosic materials can take place after gluing or during gluing. Preferably, the adhesive itself comprises the cross-linkers and/or amine cross-linkers mentioned. With the aid of said crosslinkers and/or said amine crosslinkers, the polymerization during pressing is accelerated and the cellulosic materials are therefore connected more quickly. The pressing time can therefore be less than 10 seconds per mm sheet thickness. These cross-linkers and/or amine cross-linkers may or may not be part of the adhesive. For example, the glue can be a one-part glue, where all components of the glue have already been added together and the glue is thus preserved. The glue can also be a two- or multi-part glue, wherein the glue comprises two or more parts that are joined together prior to gluing, or are applied together or successively to the cellulosic materials. In this way, unwanted prepolymerization can be avoided. The cross-linkers and/or amine cross-linkers mentioned can also be regarded as separate components that are not part of the adhesive.

In a preferred embodiment, pressing takes place at a temperature between 150°C and 250°C, with a pressing pressure between 1.5 and 5 N/mm? and this for at least 3 seconds per mm of sheet thickness. The pressing time can be, for example, 3 to 7 seconds per mm sheet thickness, depending on the pressing temperature and the pressing type. A continuous or discontinuous press can be used. When pressing, surfaces at the bottom and top are preferably treated with water, for example between 10 and 50g/m². water, sprayed, to favor heat transfer to the center of the plate and shorten the total pressing time.

In a specific embodiment, the cellulosic material is covered with adhesive by injection, atomization or by friction between the cellulosic materials or a combination of the techniques. This ensures good gluing

28 BE2022/5351 cellulosic material. This concerns a similar or the same adhesive that is applied when using current UF adhesives, as a result of which an existing adhesive step of an existing production process does not have to be adapted or only to a limited extent to the adhesive according to the invention.

This invention also concerns a method for manufacturing an adhesive for plates, in which amines and carbohydrates are provided, wherein the carbohydrates and part of the amines are combined and heated to form a pre-react, after which the remaining amines are added to the pre-react , and where additives are provided, whereby these additives are added, for example, during the formation of the prereact. The additives are additives as described above, such as bases, and/or salts of a hypochlorous acid and/or crosslinkers and/or amine cross-linkers and/or metal (hydr)oxides and/or metal salts. Said amines may include highly branched polyamides as described above. This prereact includes the carbohydrates and some of the amines. This prereact is preferably heated (and/or the carbohydrates and/or the said portion of the amines are heated prior to combining to form the prereact). In this way, the Maillard reaction takes place in the formation of this prereact and this prereact already has a number of Maillard reaction products. The rest of the amines are then added to form the glue, which is then used for gluing the cellulosic materials. This prereact may also already include some or all additives. These additives can be added at the beginning of the formation of the prereact, but can also be added during the formation of the prereact. For the formation of the prereact, for example, between 15 and 40 percent by weight of the amines can be provided, for example between 20 and 30 percent by weight, such that there are still sufficient amines present in the glue formed that have not yet reacted.

An alternative embodiment of the invention concerns an adhesive for connecting insulating materials, such as glass wool, rock wool, etc., for example to form mats, wherein the adhesive is an adhesive as described above. The preferred embodiments of the adhesive shown above also apply to this alternative embodiment. Insulating material such as glass wool, rock wool, etc. is then formed with the help of this glue. The invention therefore concerns an insulating material, such as glass wool

29 BE2022/5351 or rock wool, comprising a said glue based on amines and carbohydrates, and also a method for manufacturing insulating material, such as glass wool or rock wool, wherein a said glue based on carbohydrates and amines is provided.

According to a different variant, the invention concerns a method for producing a basic raw material comprising amino acids, wherein this basic raw material can be used for producing highly branched polyamides, preferably by polycondensation of the amino acids of the basic raw material. The basic raw material is preferably obtained by fermentation, whereby this fermentation is preferably carried out by bacteria. This basic raw material can be used to form hyperbranched polyamides by, for example, allowing polycondensation of the amino acids present to take place at a certain temperature, for example between 120°C and 180°C, for a number of hours, for example in the presence of any catalysts and/or a strong base, such as KOH. Specific embodiments of the deviating variant are shown in the non-exhaustive list below. Combinations of characteristics from this non-exhaustive list are possible, as long as they do not contradict each other: e Bacteria are provided that are capable of producing targeted amino acids via fermentation. For example, bacteria can be provided that are able to produce mainly lysine, and for example in smaller quantities one or more other amino acids such as glutamine, whereby the weight percentage of other amino acids is preferably at most 20%, preferably at most 10%, even more preferably a maximum of 5%, of the total amount of amino acids produced. These bacteria then produce a basic raw material comprising amino acids, whereby this basic raw material can be referred to as an industrial quality lysine source. The standards for an industrial grade lysine source are lower than those for a food or feed lysine source; e The basic raw material includes amino acids from the group containing arginine, glutamine, asparagine and lysine. The basic raw material can comprise one, a combination of 2, a combination of 3 or all amino acids from the above group;

30 BE2022/5351 e The basic raw material comprising amino acids is produced via fermentation by bacteria, whereby one or more carbohydrate sources and one or more ammonium sources are provided for the fermentation. The one or more ammonium sources include, for example, one or more ammonium salts, such as ammonium sulphate or diammonium phosphate. The one or more carbohydrate sources include, for example, sucrose, glucose, cellulose, hemicellulose or lignin. The carbohydrate sources are, for example, molasses, starch hydrolysates, wood-containing sources, recycled sources such as recycled MDF; e The basic raw material comprising amino acids is produced via fermentation by bacteria. These bacteria can be, for example, Corynebacterium and/or

E. coli bacteria are; e The basic raw material is produced using L-Lysine producing bacterial strains. These bacterial strains can be, for example, Corynebacterium and/or E. coli bacteria; e The fermentation takes place at a pH between 7 and 8, preferably between 7.3 and 7.7 and/or at a temperature between 28°C and 35°C, preferably between 30°C and 33°C ; e The fermentation takes place in a reactor with agitator 'stirred tank reactor' e The fermentation takes place in batch, fed batch mode or continuously; e Additives are added to increase the yield of a certain amino acid, such as L-Lysine, during fermentation.

With the aim of better demonstrating the features of the invention, some preferred embodiments are described below, by way of example without any limitation.

An example of a panel according to the invention is a wood fiber board, such as an MDF or HDF board. This wood fiber board is single-layered and consists of wood fibers and a hardened glue that connects these wood fibers together. The wood fibers are connected here using a glue based on carbohydrates, highly branched polyamides and additives. These additives include one or more of the following

31 BE2022/5351 components: bases, salts of a hypochlorous acid, crosslinkers as described above, amine crosslinkers as described above. The additives include, for example, one or more of the following components: K5CO3, NaOCl, a-dicarbonyls and epoxides. For example, the adhesive may contain the following weight percentages based on dry matter content: 69% carbohydrates, 23% highly branched polyamides, 4% K:CO3, 3% NaOCl and 1% glyoxal.

The highly branched polyamides are obtained by polycondensation of amino acids mainly comprising lysine. For example, in addition to lysine, which is preferably L-lysine, a small amount of glutamine is present. For example, glutamine makes up a maximum of 5% by weight of the amino acids present. The amino acids mentioned come from a basic raw material comprising amino acids.

This basic raw material is obtained, for example, by the fermentation of bacteria, in which these bacteria specifically form lysine.

Claims (40)

32 BE2022/5351 Conclusions 1.- A board comprising cellulosic materials, such as vegetable fibers, and a cured adhesive that connects these cellulosic materials, wherein the cured adhesive originates from an adhesive based on amines and carbohydrates and the cured adhesive comprises Maillard reaction products originating from the Maillard reaction between these amines and carbohydrates, characterized in that at least some of the amines are selected from the group comprising: highly branched polyamides and chain-shaped amines; and wherein preferably, at least some of the amines are highly branched polyamides. 2.- A plate according to claim 1, wherein the amines comprise at least highly branched polyamides and preferably the highly branched polyamides constitute at least 50% by weight, preferably at least 70% by weight, of the amines. 3. - A plate according to claim 1 or 2, wherein said highly branched polyamides are obtained by polycondensation of amino acids, wherein these amino acids are preferably selected from the group containing arginine, glutamine, asparagine and lysine. 4. - A sheet according to any of the preceding claims, wherein the highly branched polyamides comprise a first group of highly branched polyamides with a molecular weight between 500 and 100,000 g/mol, preferably between 5,000 and 50,000 g/mol and even more preferably between 10000 and 25000 g/mol. 5.- A plate according to any of the preceding claims, wherein the plate comprises one or more layers, wherein at least one said layer comprises said cellulosic materials and said cured glue, wherein preferably in this layer the weight percentage of highly branched polyamides on cellulosic materials is between 0.5 and 3, preferably between 1 and 2. 6. - A sheet according to any of the preceding claims, wherein the highly branched polyamides comprise a first group of highly branched polyamides and a second group of highly branched polyamides, wherein the average molecular weight of the first 33 BE2022/5351 group of highly branched polyamides is at least 3 times higher, preferably at least 5 times higher than the average molecular weight of the second group of highly branched polyamides and/or where the average molecular weight of the first group of highly branched polyamides is at most 15 times higher, preferably at most 10 times higher, than the average molecular weight of the second group of highly branched polyamides. 7. - A plate according to any of the preceding claims, wherein the adhesive comprises amine cross-linkers, wherein preferably these amine cross-linkers are selected from the group comprising polyketones, polyesters, isocyanate dispersions, epoxides, glyoxal and other dialdehydes. 8. - A plate according to claim 7, wherein the weight ratio of amine cross-linkers on highly branched polyamides is between 0.02 and 0.15. 9.- A plate, optionally according to one or more of the preceding claims, comprising cellulosic materials, such as vegetable fibers, and a hardened glue that connects these cellulosic materials, wherein the hardened glue comes from a glue based on amines and carbohydrates and the hardened glue contains Maillard reaction products from the Maillard reaction between these amines and carbohydrates, where the glue contains additives for controlling the Maillard reaction. 10. - A plate according to claim 9, wherein the additives comprise bases. 11. - A plate according to claim 10, wherein the bases are K:CO; include. 12.- A plate according to claim 10 or 11, wherein the plate comprises one or more layers, wherein at least one said layer comprises said cellulosic materials and said cured glue, preferably with this layer, the weight percentage of the bases on the cellulosic materials is between 0.1 and 1, even more preferably between 0.15 and 0.25. A plate according to any one of claims 9 to 12, wherein the additives comprise salts of a hypochlorous acid. 34 BE2022/5351 A plate according to claim 13, where the salts of a hypochlorous acid include sodium hypochlorite (NaOCl). 15. - A plate according to claim 13 or 14, wherein the plate comprises one or more layers, wherein at least one said layer comprises said cellulosic materials and said cured glue, preferably with this layer the weight percentage of salts of a hypochlorous acid on cellulosic materials is between 0.1 and 1, even more preferably between 0.1 and 0.2. 16. - A plate according to any one of claims 9 to 15, wherein the additives comprise crosslinkers, and these crosslinkers are preferably intermediate products formed in the Maillard reaction between amines and carbohydrates. 17. - A plate according to claim 16, wherein the crosslinkers are selected from the group comprising: α-hydroxyaldehydes, glyceraldehyde and α-dicarbonyls. 18.- A plate according to claim 16 or 17, wherein the plate comprises one or more layers, wherein at least one said layer comprises said cellulosic materials and said cured glue, wherein preferably in this layer the weight percentage of said crosslinkers is on cellulosic materials between 0.02 and 0.16, preferably between 0.04 and 0.08. 19. - A plate according to any one of claims 9 to 18, characterized in that the additives comprise metal-comprising components, for example metal oxides and/or metal hydroxides and/or metal salts. 20.- An adhesive for joining cellulosic materials, such as vegetable fibres, into panels where the adhesive is based on amines and carbohydrates, characterized in that at least some of the amines are chosen from the group comprising: highly branched polyamides and chain-shaped amides; wherein the amines preferably comprise highly branched polyamides. 35 BE2022/5351 21. - Glue according to claim 20, wherein the amines comprise highly branched polyamides and wherein the highly branched polyamides constitute at least 50% by weight, preferably at least 70% by weight, even more preferably at least 90% by weight of the amines. 22. - Glue according to claim 20 or 21, wherein the highly branched polyamides are obtained by polycondensation of amino acids, wherein these amino acids are preferably selected from the group containing arginine, glutamine, asparagine and lysine. 23. - Glue according to any one of claims 20 to 22, wherein the highly branched polyamides comprise a first group of highly branched polyamides with a molecular weight between 500 and 100,000 g/mol, preferably between 5,000 and 50,000 g/mol, and more preferably between 10000 and 25000 g/mol and that preferably the highly branched polyamides comprise a second group of highly branched polyamides, wherein the average molecular weight of the first group of highly branched polyamides is at least 3 times higher, preferably at least 5 times is higher than the average molecular weight of the second group of highly branched polyamides and/or where the average molecular weight of the first group of highly branched polyamides is at most 15 times higher, preferably at most 10 times higher than the average molecular weight of the second group highly branched polyamides and wherein further preferably, the second group of highly branched polyamides constitutes between 5 and 30 weight percent of the total weight of the highly branched polyamides, preferably between 10 and 20 weight percent. 24. - Glue according to any one of claims 20 to 23, wherein the glue comprises amine cross-linkers, wherein preferably these amine cross-linkers are selected from the group comprising polyketones, polyesters, isocyanate dispersions, epoxides, glyoxal and other dialdehydes and wherein also preferably the weight ratio of amine cross-linkers on the highly branched polyamides is between 0.02 and 0.15. 25.- An adhesive, optionally according to one or more of claims 20 to 24, for connecting cellulosic materials, such as vegetable fibers, into plates 36 BE2022/5351 where the glue is based on amines and carbohydrates, where the glue contains additives for controlling the Maillard reaction. 26. - An adhesive according to claim 25, wherein the additives include bases for controlling the pH. 27. - An adhesive according to claim 26, wherein the bases are K, CO; include. 28. - An adhesive according to claim 25 or 26, wherein the bases make up between 1 and 20 weight percent of the adhesive's dry matter content. 29. - An adhesive according to any one of claims 25 to 28, wherein the additives comprise salts of a hypochlorous acid. 30. - An adhesive according to claim 29, where the salts of a hypochlorous acid include sodium hypochlorite (NaOCl). 31. - An adhesive according to claim 29 or 30, wherein the salts of a hypochlorous acid constitute between 1 and 20 weight percent of the adhesive's dry matter content. 32. - An adhesive according to any one of claims 25 to 31, wherein the additives comprise crosslinkers, and these crosslinkers are preferably intermediate products formed during the Maillard reaction between amines and carbohydrates. 33. - An adhesive according to claim 32, wherein the crosslinkers are selected from the group comprising: α-hydroxyaldehydes, glyceraldehyde and α-dicarbonyls. 34. - An adhesive according to claim 32 or 33, wherein crosslinkers make up between 0.3 and 3 percent by weight of the adhesive's dry matter content. 35. - An adhesive according to any one of claims 25 to 34, wherein the additives comprise metal-comprising components, for example metal oxides and/or metal hydroxides and/or metal salts. 37 BE2022/5351 Glue according to any one of claims 20 to 35, wherein the weight ratio of amines to the total weight of amines and carbohydrates is at most 0.4, and preferably at least 0.15. 37.- Method for forming plates comprising cellulosic materials, such as vegetable fibres, wherein cellulosic materials are provided and a glue is applied to these cellulosic materials, after which these glued cellulosic materials are pressed into a plate-shaped material for thus forming plates, characterized in that the glue is an glue as in one or more of claims 20 to 36. 38. - Method according to claim 37, wherein the plate comprises one or more layers, wherein these layers are pressed together and wherein at least one said layer comprises said cellulosic materials and said glue, wherein the weight ratio of glue to cellulosic materials in this layer is between 0.03 and 0.10. 39. - Method according to claim 37 or 38, wherein the pressing takes place at a temperature between 150°C and 250°C, with a pressing pressure between 1.5 and 5 N/mm? and this for at least 3 seconds per mm of sheet thickness. 40.- Method for the production of an adhesive for plates, in which amines and carbohydrates are provided, wherein the carbohydrates and part of the amines are combined and heated to form a prereact, after which the remaining amines are added to the prereact, with the feature that additives are provided, whereby these additives are added, for example, during the formation of the prereact or after the formation of the prereact.