Binder Composition

Abstract

To provide a method for producing a binder composition using lignin.SOLUTION: The method comprises: i) preparing an ingredient crushed lignin agglomerates, where at least 90 wt.% of the crushed lignin agglomerates have particle size of at most 10 mm; ii) dissolving the prepared ingredient in an aqueous solvent composition, where at least 95 wt.% of the total amount of the ingredient provided into the aqueous solvent composition is dissolved in the aqueous solvent composition within at most 60 minutes; and iii) heating the composition formed in step ii) at a temperature of 60-150°C in the presence of a crosslinking agent and a compound selected from the class of phenols for polymerizing the ingredient, the crosslinking agent, and the compound selected from the class of phenols.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a method for making a binder composition. The present disclosure further relates to a binder composition and uses thereof. [Background technology]

[0002] Lignin is a natural polymer that can be extracted, for example, from wood. Because lignin is a natural biopolymer, its use as an ingredient in adhesives instead of synthetic substances has been explored to create more environmentally friendly adhesive compositions. In particular, the possibility of replacing synthetic phenol in phenolic resins, such as phenol-formaldehyde resins, continues to be a research goal. Lignin can be used to reduce the amount of synthetic phenol in resin compositions. Lignin has previously been used to replace phenol in the production of lignin-phenol-formaldehyde resins.

[0003] However, currently known lignin-based resins are not suitable for all applications for which conventional phenolic resins are used. For example, currently known lignin-based resins are not suitable for high-pressure laminates. High-pressure laminates (HPL), also known as plastic laminates, can be produced by fusing multiple layers of paper, fabric, or other core materials together under the influence of heat and pressure using a thermosetting resin as a binder. The present inventors have recognized the need for a method that can result in higher phenol substitution in the resin, and therefore a more environmentally friendly binder composition with suitable properties for use in various applications, such as high-pressure laminates. Summary of the Invention [Means for solving the problem]

[0004] A method for producing a binder composition is disclosed, which may include the steps of: i) providing a feedstock, crushed lignin aggregates, wherein at least 90% by weight of the crushed lignin aggregates have a particle size of 10 mm or less; ii) dissolving the prepared feedstock in an aqueous solvent composition, wherein at least 95% by weight of the total amount of the feedstock provided in the aqueous solvent composition is dissolved in the aqueous solvent composition within a maximum of 60 minutes; and iii) heating the composition formed in step ii) at a temperature of 60-150°C in the presence of a crosslinker and a compound selected from the class of phenols to polymerize the feedstock, the compound selected from the class of phenols, and the crosslinker.

[0005] Further disclosed are binder compositions obtainable by the methods disclosed herein.

[0006] Further disclosed are uses of the binder compositions obtainable by the methods disclosed herein. [Brief explanation of the drawings]

[0007] The accompanying drawings are included to provide a further understanding of the embodiments and are included to form a part of this specification, and illustrate various embodiments.

[0008] [Figure 1] FIG. 1 presents the results from Example 1. [Figure 2] Figure 2 presents stereomicroscope photographs from uncrushed lignin (Figure 2a) and crushed lignin (Figure 2b) measured using a stereomicroscope Wild M5A. [Figure 3] FIG. 3 shows SEM images from uncrushed lignin (3a) and crushed lignin (3b) measured using a FE SEM Hitachi SU 5000 (SEM = scanning electron microscope). DETAILED DESCRIPTION OF THE INVENTION

[0009] A method for producing a binder composition is disclosed, which may include the steps of: i) providing a raw material, crushed lignin aggregates, wherein at least 90% by weight of the crushed lignin aggregates have a particle size of 10 mm or less; ii) dissolving the prepared raw material in an aqueous solvent composition, wherein at least 95% by weight of the total amount of the raw material provided in the aqueous solvent composition is dissolved in the aqueous solvent composition within a maximum of 60 minutes; and iii) heating the composition formed in step ii) at a temperature of 60-150°C in the presence of a crosslinking agent and a compound selected from the class of phenols to polymerize the raw material, the compound selected from the class of phenols, and the crosslinking agent.

[0010] Further disclosed are binder compositions obtainable by the methods defined herein.

[0011] Further disclosed is the use of the binder composition obtainable by the process defined herein for the manufacture of a high pressure laminate, a continuous pressure laminate, rock wool, insulation wool, oriented strand board, a panel facing film, or a plywood facing film.

[0012] The present inventors have surprisingly found that when preparing crushed lignin aggregates of raw materials, it is possible to efficiently dissolve the raw materials used in an aqueous solvent composition. The present inventors have surprisingly found that not only the particle size of the lignin raw material, but also the crushing process itself, affects the raw material's ability to dissolve in an aqueous solvent composition. While not bound by any particular theory as to why crushed lignin aggregates can be dissolved more efficiently than corresponding lignin that has not been subjected to any form of crushing, it is believed that the crushing process may soften the lignin raw material, and therefore the molecules of the lignin aggregates are more easily dissolved from the surface layer of the aggregate. Presence of hard lignin particles or aggregates may adversely affect the raw material's ability to dissolve in an aqueous solvent composition, which may result in hard, rock-like lignin aggregates remaining present during subsequent heat treatment steps and adversely affecting the properties of the formed binder composition. Such hard lignin particles or aggregates may have formed during storage of the lignin, for example, in large storage bags, or during a previous lignin separation and recovery process. Hard, stone-like aggregates present in the feedstock may remain as inert fillers during the heat treatment or polymerization process. Crushing the feedstock not only provides suitably sized lignin aggregates, but also reduces the size of potential impurities, such as fibrous particles, which may reduce the adverse impact they may have on the production of the binder composition. Furthermore, in applications such as oriented strand board production that involve spraying the binder composition, undissolved hard particles may clog the nozzles used.

[0013] For purposes of this specification, the term "lignin aggregate" may refer to at least two lignin particles that are bonded together. A lignin particle may be considered to be formed from one lignin polymer. Lignin can be considered to be an irregular, randomly cross-linked polymer of phenylpropane units joined by different linking groups.

[0014] The surface of the crushed lignin aggregates is rougher than the surface of lignin aggregates that have not been subjected to the crushing process.

[0015] The crushed lignin aggregates may have a particle size of 9 mm or less, or 8 mm or less, or 7 mm or less, or 6 mm or less, or 5 mm or less, or 4 mm or less. The crushed lignin aggregates may have a particle size of at least 0.15 mm, or at least 0.5 mm, or at least 1 mm. The particle size of the lignin aggregates used can be determined, for example, by sieving the lignin aggregates.

[0016] In one embodiment, at least 95%, or at least 99%, or at least 99.5% by weight of the crushed lignin aggregates have a particle size of 10 mm or less, hi one embodiment, at least 90%, or at least 95%, or at least 99% by weight of the crushed lignin aggregates have a particle size of 9 mm or less, or 8 mm or less, or 7 mm or less, or 6 mm or less, or 5 mm or less, or 4 mm or less.

[0017] The present inventors have surprisingly recognized that controlling the particle size of the lignin aggregates has the additional utility of beneficially influencing the solubility of the lignin feedstock. It has been recognized that particle size can affect the solubility of the lignin feedstock because molecules dissolve more readily from the surface layers of the lignin particles or aggregates. As particle size decreases, the specific surface area increases, which allows for more rapid formation of dispersions and subsequent reaction during the heat treatment or polymerization step.

[0018] Step i) of providing the feedstock crushed lignin aggregates may comprise subjecting the lignin to a process to produce the crushed lignin aggregates, which process may be selected from the group consisting of crushing, grinding, rubbing, pulverizing, stripping, and combinations of any of these.

[0019] The lignin subjected to the process to produce the crushed lignin aggregate may have a dry matter content of at least 50%, or at least 65%.

[0020] In one embodiment, step i) of preparing the raw material crushed lignin aggregates comprises subjecting the lignin to a process selected from the group consisting of crushing, grinding, rubbing, pulverizing, exfoliating, and combinations of any of these.

[0021] In one embodiment, step i) of providing the feedstock crushed lignin aggregates comprises subjecting the lignin to one or more of the following: crushing, grinding, rubbing, pulverizing, or peeling. In one embodiment, step i) of providing the feedstock crushed lignin aggregates comprises subjecting the lignin to at least two of the following: crushing, grinding, rubbing, pulverizing, peeling, drying, sieving, or sieving.

[0022] In one embodiment, step i) of preparing the raw material crushed lignin aggregates comprises subjecting the lignin to sieving and / or sieving during and / or after a process selected from the group consisting of crushing, grinding, rubbing, pulverizing, peeling, and combinations of any of these.

[0023] The grinding can be coarse grinding.The grinding can be coarse grinding.

[0024] In one embodiment, step i) of providing the feedstock crushed lignin aggregates does not only include sieving and / or screening of the lignin.

[0025] Processing lignin using at least one of the above process options has the added benefit of activating and softening the feedstock, such that hard, rock-like particles or aggregates may be absent, or at least their amount reduced, compared to the situation before the lignin was subjected to these processing steps. Crushing the lignin may result in the lignin aggregates being broken down and the particle surfaces becoming softer, which may make the feedstock crushed lignin aggregates more easily dissolve in an aqueous solvent composition. The feedstock crushed lignin aggregates may be coarser and therefore more quickly dissolve than lignin that has not been subjected to the above processing steps.

[0026] For purposes of this specification, the term "lignin" may refer to lignin derived from any suitable lignin source. In one embodiment, the lignin is substantially pure lignin. The expression "substantially pure lignin" should be understood as at least 70% pure lignin, or at least 90% pure lignin, or at least 95% pure lignin, or at least 98% pure lignin. This substantially pure lignin may contain 30% or less, or 10% or less, or 5% or less, or 2% or less of other components and / or impurities. Extractives and carbohydrates, such as hemicellulose, may be mentioned as examples of such other components.

[0027] The lignin may contain less than 30%, or less than 10%, or less than 5%, or less than 2% by weight of carbohydrates. The amount of carbohydrates present in the lignin can be measured by high performance anion exchange chromatography using a pulsed amperometric detector (HPAE-PAD) according to standard SCAN-CM 71.

[0028] The ash percentage of the lignin may be less than 7.5% by weight, or less than 5% by weight, or less than 3% by weight, or less than 1% by weight. Ash content can be determined by carbonizing and rapidly combusting a lignin sample (e.g., 20-200°C for 30 minutes, followed by adjusting the temperature to 200-600°C for 1 hour, and then adjusting the temperature to 600-700°C for 1 hour) so that the alkali salts do not melt before the organic matter has burned off, and finally igniting the lignin sample at 700°C for 1 hour. The ash content of a lignin sample refers to the mass of the sample remaining after combustion and ignition, and is presented as a percentage of the dry content of the sample. In one embodiment, the lignin is industrial lignin. For purposes of this specification, the term "industrial lignin" may refer to lignin derived from any technological process from lignin in any biomass. In one embodiment, industrial lignin is lignin received from an industrial process.

[0029] In one embodiment, the lignin is selected from the group consisting of kraft lignin, steam exploded lignin, biorefinery lignin, supercritically separated lignin, hydrolyzed lignin, flash precipitated lignin, biomass-derived lignin, lignin from an alkaline pulping process, lignin from a soda process, lignin from organosolv pulping, lignin from an alkaline process, lignin from an enzymatic hydrolysis process, and any combination thereof. In one embodiment, the lignin is wood-based lignin. The lignin can be derived from softwood, hardwood, annual plants, or any combination thereof.

[0030] "Kraft lignin," as used herein, unless otherwise specified, refers to lignin derived from kraft black liquor. Black liquor is an alkaline aqueous solution of lignin residues, hemicellulose, and inorganic chemicals used in the kraft pulping process. Black liquor from the pulping process contains components derived from various softwood and hardwood species in varying proportions. Lignin can be separated from black liquor by various techniques, including precipitation and filtration. Lignin typically begins to precipitate at pH values ​​below 11-12. Different pH values ​​can be used to precipitate lignin fractions with different properties. These lignin fractions differ from each other by molecular weight distribution, e.g., Mw and Mn, polydispersity, hemicellulose, and extractive content. The molar mass of lignin precipitated at higher pH values ​​is higher than that of lignin precipitated at lower pH values. Furthermore, the molecular weight distribution of lignin fractions precipitated at lower pH values ​​is broader than that of lignin fractions precipitated at higher pH values. The precipitated lignin can be purified from inorganic impurities, hemicellulose, and wood extractives using an acidic washing step. Further purification can be achieved by filtration.

[0031] The term "flash precipitated lignin" is understood herein as lignin precipitated from black liquor in a continuous process by lowering the pH of the black liquor stream to a lignin precipitation level using a carbon dioxide-based acidifying agent, preferably carbon dioxide, under the influence of an overpressure of 200-1000 kPa, and then suddenly releasing the pressure to precipitate the lignin. A method for producing flash precipitated lignin is disclosed in Finnish Patent Application No. 20106073. The residence time in the above process is less than 300 s. Flash precipitated lignin particles with a particle size of less than 2 μm form agglomerates, which can be separated from the black liquor using, for example, filtration. The advantage of flash precipitated lignin is its higher reactivity compared to conventional kraft lignin. Flash precipitated lignin can be purified and / or activated as needed for further processing.

[0032] Lignin may be derived from an alkaline process, which begins with liquefying the biomass using a strong alkali, which can be followed by a neutralization process. After alkaline treatment, the lignin can be precipitated in a manner similar to that presented above.

[0033] Lignin may be derived from steam explosion, which is a pulping and extraction technique that can be applied to wood and other fibrous organic materials.

[0034] "Biorefinery lignin," as used herein, unless otherwise specified, should be understood as lignin that can be recovered from a purification facility or process where biomass is converted into fuels, chemicals, and other materials.

[0035] "Supercritically separated lignin," as used herein, unless otherwise specified, should be understood as lignin that can be recovered from biomass using supercritical fluid separation or extraction techniques. The supercritical state corresponds to temperatures and pressures above the critical point for a given substance. At the supercritical state, distinct liquid and gas phases do not exist. Supercritical water or supercritical fluid extraction is a method of decomposing and converting biomass into cellulosic sugars by using water or a liquid under supercritical conditions. This water or liquid, acting as a solvent, extracts the sugars from the cellulose plant matter, leaving the lignin as solid particles.

[0036] The lignin may be derived from a hydrolysis process. Lignin derived from a hydrolysis process can be recovered from paper pulp or wood chemical processes.

[0037] The lignin may be derived from an organosolv process, which is a pulping technique that uses organic solvents to solubilize lignin and hemicellulose.

[0038] The lignin may be lignin from an enzymatic hydrolysis process, which is a process in which enzymes use the addition of water to assist in breaking bonds within molecules. In one embodiment, the enzymatic hydrolysis comprises the enzymatic hydrolysis of cellulose.

[0039] In one embodiment, the aqueous solvent composition comprises or consists of a compound selected from the class of phenols and / or alkalis, and may be an aqueous solvent composition of alkalis, an aqueous solvent composition of a compound selected from the class of phenols, or an aqueous solvent composition of a compound selected from the class of phenols and alkalis.

[0040] The compound selected from the class of phenols may be selected from the group consisting of phenol, cresol, resorcinol, and any combination thereof, hi one embodiment, the compound selected from the class of phenols is phenol.

[0041] The concentration of the compound selected from the class of phenols in step ii) may be 10-60% by weight, or 20-50% by weight, or 30-45% by weight, based on the total weight of the composition in step ii).

[0042] The concentration of the raw material in step ii) may be 10 to 40 wt %, or 20 to 30 wt %, based on the total weight of the composition in step ii).

[0043] In one embodiment, the alkali is an alkali metal hydroxide, hi one embodiment, the alkali is sodium hydroxide, potassium hydroxide, or a combination thereof.

[0044] The concentration of the alkali in step ii) may be 0.1 to 11 wt %, or 0.3 to 9 wt %, or 0.5 to 5 wt %, or 1 to 2 wt %, based on the total weight of the composition in step ii).

[0045] The temperature of the composition in step ii) can be kept at 15 to 95°C, or 18 to 80°C, or 20 to 70°C, or 25 to 60°C, or 30 to 50°C, or 35 to 40°C.

[0046] In one embodiment, at least 95% by weight of the total amount of ingredients provided in the aqueous solvent composition is dissolved in the aqueous solvent composition within a maximum of 45 minutes, or within a maximum of 30 minutes, or within a maximum of 15 minutes.

[0047] In one embodiment, at least 97% by weight, or at least 99% by weight, of the total amount of ingredients provided in the aqueous solvent composition are dissolved in the aqueous solvent composition within a maximum of 60 minutes, or within a maximum of 45 minutes, or within a maximum of 30 minutes, or within a maximum of 15 minutes.

[0048] The ability to quickly dissolve the raw material crushed lignin aggregates in the aqueous solvent composition has the additional benefit of beneficially impacting the subsequent steps of allowing polymerization of the lignin raw material, the compound selected from the class of phenols, and the crosslinking agent by reducing the time required for heating step iii), while providing a formed binder composition of uniform quality.

[0049] Once the prepared raw materials have been dissolved in the aqueous solvent composition, step iii) of heating the formed composition may be carried out in the presence of a crosslinker and a compound selected from the class of phenols.

[0050] The crosslinking agent may be selected from the group consisting of aldehydes, aldehyde derivatives, aldehyde-forming compounds, and any combination thereof. In one embodiment, the aldehyde derivative is hexamethylenetetramine, paraformaldehyde, or trioxane. In one embodiment, the crosslinking agent is selected from the group consisting of aromatic aldehydes, glyoxal, furfuryl alcohol, caprolactam, and glycol compounds. The aldehyde can be formaldehyde. The aromatic aldehyde can be furfuryl aldehyde. In one embodiment, the crosslinking agent is an aldehyde, preferably formaldehyde, paraformaldehyde, or a combination thereof.

[0051] The compound selected from the class of phenols may be selected from the group consisting of phenol, cresol, resorcinol, and any combination thereof, hi one embodiment, the compound selected from the class of phenols is phenol.

[0052] In one embodiment, the compound selected from the phenols class is provided in the composition of step ii) as part of the aqueous solvent composition and / or in step iii). The compound selected from the phenols class may be added to the composition of step iii). However, if the aqueous solvent composition in which the raw material is dissolved in step ii) contains a compound selected from the phenols class, it may not be necessary to separately add a compound selected from the phenols class in step iii). However, even if the aqueous solvent composition contains a compound selected from the phenols class, a further amount of a compound selected from the phenols class may be added in step iii).

[0053] The heating in step iii) may be carried out in the presence of a catalyst. The catalyst may be an alkali. The catalyst may be an alkali metal hydroxide. The catalyst may be sodium hydroxide, potassium hydroxide, or a combination thereof. The concentration of the catalyst may be 0.1 to 15 wt %, or 0.5 to 12 wt %, or 3 to 10 wt %, or 5 to 8 wt %, based on the total weight of the composition in step iii). If the aqueous solvent composition in which the raw materials are dissolved in step ii) contains an alkali, it may not be necessary to separately add a catalyst in step iii). However, even if the aqueous solvent composition contains an alkali, a certain amount of catalyst may be added in step iii).

[0054] The entire amount of catalyst used in step iii) may be added substantially all at once. The entire amount of crosslinker used in the process and the entire amount of catalyst used in the process can be mixed with the composition formed in step ii) during step iii).

[0055] Step iii) may comprise heating the composition formed in step ii) at a temperature of 65 to 140°C, or at a temperature of 70 to 100°C, or at a temperature of 75 to 95°C, or at a temperature of 80 to 90°C.

[0056] In one embodiment, the polymerization of the lignin raw material, the compound selected from the class of phenols, and the crosslinker in step iii) is completed within 0.5 to 6 hours, or within 1.0 to 5 hours, or within 2 to 4 hours, or within 1.5 to 3.0 hours.

[0057] The heating step iii) can be continued until a binder composition is formed having a weight average molecular weight of 500 to 6000 g / mol, or 1000 to 4000 g / mol.

[0058] The weight-average molecular weight of the binder composition can be determined using high-performance size-exclusion chromatography. In one embodiment, the weight-average molecular weight of the binder composition is determined using high-performance size-exclusion chromatography as follows: two parallel measurements are performed. 0.1 M NaOH is used as the eluent. Calibration is performed using Na-polystyrene sulfonate standards with molecular weights of 1,100 to 73,900 g / mol. For quality control, standard quality kraft lignin and PSS molecular weight standards are used. The columns used are a PSS MCX precolumn packed with a sulfonated styrene-divinylbenzene copolymer matrix, 1,000 Å and 100,000 Å separation columns. An isocratic run program is used. The run time is 45 minutes. The injection volume is 50 μl. The flow rate is 0.5 ml per minute. The temperature is 25°C. As a result of this chromatography, it is possible to report values ​​for number average molecular weight (Mn), weight average molecular weight (Mw), peak molecular weight (Mp) and polydispersity index (PDI).

[0059] Heating the formed composition in step iii) may be carried out to polymerize the reactant components, i.e., the crushed lignin aggregates, the compound selected from the class of phenolics, and the crosslinker, so that the viscosity of the binder composition increases. This heating may be continued until a predetermined viscosity value is produced. The predetermined viscosity value of the final binder composition may vary depending on the particular application for which the binder composition will be used.

[0060] In one embodiment, the heating step iii) is continued until the binder composition has a viscosity value of 30 to 300 cP, or 40 to 200 cP, or 50 to 150 cP, or 80 to 120 cP, as measured in step iii) using a rotational viscometer (digital Brookfield viscometer LVDV-II+ Pro; cone spindle) at a temperature of 25°C.

[0061] In one embodiment, the heating step (iii) is carried out as a one-step reaction. In one embodiment, the heating step (iii) is carried out in at least two steps. The temperatures in the at least two steps may be the same or different.

[0062] The exact amounts and ingredients used to prepare the binder composition can vary, and the selection of different ingredients and their amounts is within the knowledge of one skilled in the art based on this specification. Temperature and all other values ​​can be controlled and adjusted as needed during the manufacturing process.

[0063] The binder compositions described herein have the additional advantage of having properties suitable for the production of high-pressure laminates, continuous pressure laminates, rock wool, insulating wool, oriented strand board, panel surface films, or plywood surface films. The methods described herein have the additional advantage of providing raw materials that can be efficiently and quickly dissolved in aqueous solvent compositions. The ability to efficiently dissolve the raw materials has the additional advantage that the raw materials are thus activated and in a reactive form for the subsequent heat treatment step, thereby achieving a uniform and appropriate binder composition. [Example]

[0064] Reference will now be made in detail to various embodiments.

[0065] The following description discloses several embodiments in sufficient detail to enable one skilled in the art to utilize the embodiments based on the present disclosure, and not every step or feature of the embodiments is discussed in detail, as many of the steps or features will be apparent to one skilled in the art based on this specification.

[0066] Example 1 - Dissolving lignin samples in aqueous phenolic compositions In this example, the effect of preparing crushed lignin aggregates compared to uncrushed lignin was determined based on the following dissolution test: An aqueous composition of phenol was used as the aqueous solvent composition.

[0067] For all tests, 1000 g of the aqueous phenolic composition was first added to a reactor and heated to a temperature of 50° C. The lignin feedstock was then added to the reactor and the lignin feedstock was dissolved in the aqueous phenolic composition with stirring. The following test procedures were performed simultaneously: 1) Mix for 15 minutes ⇒ Sift through a 400 μm sieve to see if there are any undissolved particles + take a photo. Then put everything back into the reactor; 2) Continue mixing for another 15 minutes (30 minutes total) ⇒ Sift through a 400 μm sieve to see any undissolved particles + photograph. Then return everything to the reactor; 3) Continue mixing for another 15 minutes (45 minutes total) ⇒ Sift through a 400 μm sieve to see any undissolved particles + photograph. Then return everything to the reactor; 4) Continue mixing for another 15 minutes (60 minutes total) ⇒ Sift through a 400 μm sieve to see any undissolved particles + photograph. Stop the test after 60 minutes.

[0068] The following samples were tested: Sample 1: Uncrushed lignin Sample 2: Uncrushed lignin sieved by vibrating sieve Sample 3: Lignin crushed using a jawbreaker (Laitex Oy, model RML 220) Sample 4: Lignin crushed using a lump crusher (Telschig GmbH, CEMBREAK KB-330-ED / S-6-P) Sample 5: Lignin crushed using Atrex (Megatrex Oy, Atrex G Series, Model CD500 G 45-P)

[0069] The results from the above tests are presented in Figure 1. As can be seen from the accompanying results, the crushed lignin aggregates dissolve more efficiently in aqueous compositions of phenol than the uncrushed lignin aggregates and the lignin aggregates that were only subjected to sieving.

[0070] Sample No. 4 was further analyzed by subjecting the sample to sieving before and after the process of producing the crushed lignin aggregates. A total of 3 kg of this sample was subjected to sieving using a Retsch shaking sieve by using the following sizes of sieves: 16 mm, 10 mm, 5 mm, 2 mm, and 1 mm. The sieving time was 15 minutes at an amplitude of 60. The results from this sieving are presented in Table 1 below.

[0071] [Table 1]

[0072] Additionally, the samples in Table 1 were subjected to binocular stereomicroscope imaging, measured using a Wild M5A binocular stereomicroscope. The results are presented in Figure 2a (uncrushed) and Figure 2b (crushed). As can be seen from Figure 2, the surface of the crushed sample, i.e., the surface of the lignin aggregates, was affected by the crushing process. Note that although the surface of the lignin aggregates was affected by the crushing process, their dissolution in the aqueous solvent composition was also beneficially affected.

[0073] Additionally, the samples in Table 1 were subjected to SEM (scanning electron microscopy) imaging using a Hitachi SU 5000 FE SEM. The results are presented in Figure 3a (uncrushed) and Figure 3b (crushed). Figures 3a and 3b show that the surfaces of the crushed lignin aggregates are more porous than those of the uncrushed lignin aggregates. As can be seen from Figure 3a, the surface of the uncrushed lignin aggregates contains distinctly smoother and denser areas. Because the surface of the lignin aggregates becomes more porous as a result of the crushing process, chemicals may penetrate the lignin aggregates more easily, thus potentially helping the lignin aggregates to dissolve more quickly in aqueous solvent compositions. During imaging, it was further noted that distinct lignin particles loosened when the electron beam struck the surface of the crushed lignin aggregates. This type of phenomenon was not observed when the electron beam was applied to uncrushed lignin aggregates.

[0074] Furthermore, producing binder compositions from using the above samples showed that the use of the shredded lignin aggregates beneficially affects subsequent binder composition production, for example, by providing produced binder compositions with uniform quality compared to binder compositions produced by using unshredded lignin feedstock.

[0075] It is obvious to those skilled in the art that with the advancement of technology, the basic concept may be implemented in various ways. Therefore, the embodiments are not limited to the above examples, instead, the embodiments may vary within the scope of the claims.

[0076] The embodiments described hereinbefore may be used in any combination with each other. Some of the embodiments may be combined together to form further embodiments. The methods, compositions, or uses disclosed herein may include at least one of the embodiments described hereinbefore. It will be understood that the benefits and advantages described above may relate to one embodiment or to several embodiments. Embodiments are not limited to those that solve any or all of the problems described above or those that have any or all of the benefits and advantages described above. It is further understood that reference to an item preceded by "an" refers to one or more of those items. The term "comprising" is used herein to mean "including" the subsequent feature(s) or act(s) without excluding the presence of one or more additional features.

Claims

1. A method for producing a binder composition, comprising: i) providing a feedstock of crushed lignin aggregates, the crushed lignin aggregates having a particle size of at least 0.5 mm, and at least 90% by weight of the crushed lignin aggregates having a particle size of 10 mm or less; ii) dissolving the prepared raw materials in an aqueous solvent composition, wherein at least 95% by weight of the total amount of the raw materials provided in the aqueous solvent composition is dissolved in the aqueous solvent composition within a maximum of 60 minutes; iii) heating the composition formed in step ii) in the presence of a crosslinking agent and a compound selected from the class of phenols at a temperature of 60-150°C to polymerize the raw materials, the crosslinking agent, and the compound selected from the class of phenols; A method for providing

2. 2. The method of claim 1, wherein at least 95% by weight, or at least 99% by weight, or at least 99.5% by weight of the crushed lignin aggregates have a particle size of 10 mm or less.

3. 3. The method of claim 1 or claim 2, wherein at least 90% by weight, or at least 95% by weight, or at least 99% by weight of the crushed lignin aggregates have a particle size of 9 mm or less, or 8 mm or less, or 7 mm or less, or 6 mm or less, or 5 mm or less, or 4 mm or less.

4. 4. The method according to claim 1, wherein the aqueous solvent composition comprises or consists of a compound selected from the class of phenols and / or alkalis.

5. 5. The method according to any one of claims 1 to 4, wherein the compound selected from the class of phenols is provided in the composition of step ii) as part of the aqueous solvent composition and / or in step iii).

6. 6. The method of any one of claims 1 to 5, wherein step i) of preparing the raw material crushed lignin aggregates comprises subjecting the lignin to a process selected from the group consisting of crushing, grinding, rubbing, pulverizing, peeling, and combinations of any of these.

7. 7. The method of claim 1, wherein at least 95 wt. % of the total amount of the ingredients provided to the aqueous solvent composition is dissolved in the aqueous solvent composition within a maximum of 45 minutes, or within a maximum of 30 minutes, or within a maximum of 15 minutes.

8. 8. The method of any one of claims 1 to 7, wherein at least 97 wt. %, or at least 99 wt. %, of the total amount of the ingredients provided to the aqueous solvent composition are dissolved in the aqueous solvent composition within a time period of at most 60 minutes, or within a time period of at most 45 minutes, or within a time period of at most 30 minutes, or within a time period of at most 15 minutes.

9. 5. The method of claim 4, wherein the concentration of the compound selected from the class of phenols in step ii) is 10 to 60 wt. %, or 20 to 50 wt. %, or 30 to 45 wt. %, based on the total weight of the composition in step ii).

10. 10. The method of any one of claims 1 to 9, wherein the polymerization of the raw materials, the compound selected from the class of phenols, and the crosslinker in step iii) is completed within 0.5 to 6 hours, or 1.0 to 5 hours, or 2 to 4 hours, or 1.5 to 3.0 hours.

11. 11. The method of any one of claims 1 to 10, wherein the heating step iii) is continued until a binder composition is formed having a weight average molecular weight of 500 to 6000 g / mol, or 1000 to 4000 g / mol.

12. 12. The method of any one of claims 1 to 11, wherein the heating step iii) is continued until a binder composition is formed having a viscosity value of from 30 to 300 cP, or from 40 to 200 cP, or from 50 to 150 cP, or from 80 to 120 cP.

13. 13. Use of a binder composition obtainable by the method according to any one of claims 1 to 12 for the production of high pressure laminates, continuous pressure laminates, rock wool, insulating wool, oriented strand board, panel facing films or plywood facing films.

Images