Thermosetting binder composition for the manufacture of barrier products containing water-soluble oligomer esters

Abstract

The present invention relates to a composition comprising water and a water-soluble oligomeric ester comprising: at least one carbohydrate selected from reducing sugars, non-reducing sugars and hydrogenated sugars, said hydrogenated sugars being selected from the group consisting of erythritol, arabitol, xylitol, sorbitol, mannitol, iditol, maltitol, isomaltitol, lactitol, cellobitol, palatinitol, maltotritol and hydrogenated products of starch hydrolysates or of hydrolysates of lignocellulosic materials; at least one diol; and at least one polycarboxylic acid, a water-soluble oligomeric ester of the formula: The binder composition has a solid content of 40% by mass to 80% by mass, the water-soluble oligomeric ester comprises at least 70% by weight of the solids of the thermosetting binder composition; The thermosetting binder composition relates to a thermosetting binder composition in which the ratio of the number of hydroxyl groups of all diols to the number of hydroxyl groups of all diols and carbohydrates is 5% to 50%.

Description

[Technical Field]

[0001] The present invention relates to a thermosetting aqueous binder based on a water-soluble oligomeric ester obtained by a reaction between a carbohydrate, a diol, and a polycarboxylic acid.

[0002] The present invention also relates to the use of such binders for binding organic or mineral fibers; preferably mineral wool fibers, particularly glass wool or rock wool.

[0003] For several years, it has been known to use aqueous compositions based on bio-derived reagents, particularly sugars, as thermosetting binders for mineral wool or nonwoven fabric products based on mineral fibers.

[0004] It has been particularly proposed to form thermosetting polyesters by reacting a reducing sugar and / or a non-reducing sugar and / or a hydrogenated sugar having a hydroxyl group with a polycarboxylic acid in the presence of a catalyst, usually sodium hypophosphite (International Publication Nos. 2009 / 080938, 2010 / 029266, 2013 / 014399, and 2013 / 021112).

[0005] International application, International Publication No. 2012 / 138723, discloses binder compositions based on oligomers and / or polymeric carbohydrates (2 to 20 dextrose equivalents) and crosslinking agents selected from polycarboxylic acids. These compositions also include oligoesters obtained by the reaction of polycarboxylic acids with glycerol, having a weighted average mass of 1500 to 5000.

[0006] The sizing compositions described in the aforementioned literature are dilute, not very viscous aqueous solutions and monomer reagents. These are typically sprayed onto mineral fibers that are still hot immediately after formation. Evaporation of the aqueous phase begins immediately after application of the sizing composition to the fibers. When the fibers are collected on a recovery belt and assembled into a mat, the fibers are sticky, and the sizing composition film surrounding the glass fibers still contains water.

[0007] Only after the sized mineral wool mat is placed in a thermostat-controlled oven at a temperature typically exceeding 180°C or even exceeding 200°C does the evaporation of water complete and the esterification reaction between the reagents begin.

[0008] By heating the sized fiber mat at a high temperature for tens or hundreds of seconds, crosslinking of the reaction system through esterification and formation of a water-insoluble binder occur, but some of the reagents also undergo thermal decomposition and evaporation of the resulting decomposition products. The gaseous components formed in the oven are partially discharged through an exhaust pipe. The exhaust gas or flue gas is treated in a cleaning system, and the cleaning water is then recirculated in a closed system.

[0009] When a sizing composition contains citric acid, the resulting fumes contain many acidic compounds (citric acid, citraconic acid, itaconic acid, propionic acid, acetic acid, formic acid) that must be neutralized by adding a base to prevent corrosion and deterioration of the equipment. However, adding a base presents problems. Indeed, in equipment that manufactures barrier products based on mineral wool, wash water is reinjected into the system and used, in particular, for the preparation of binders and sizing compositions. The presence of large amounts of base or salt in the sizing composition tends to increase the pH, which can inhibit esterification reactions (crosslinking).

[0010] In its international application, International Publication No. 2019 / 202248, the applicant proposed applying an aqueous composition to mineral wool fibers that comprises an oligoester pre-synthesized by the reaction of carbohydrates and polycarboxylic acids in an anhydrous medium, rather than an aqueous composition comprising a mixture of one or more carbohydrates and one or more polycarboxylic acids. By replacing the monomer (carbohydrate and polycarboxylic acid) reagents with a soluble oligomer, the amount of acidic decomposition products in flue gas could be significantly reduced.

[0011] Furthermore, the use of oligomers makes it possible to significantly lower the crosslinking initiation temperature of the reaction system and / or significantly shorten the duration required to fully cure the binder at a given oven temperature.

[0012] In continuing research to optimize the method for producing mineral wool described in International Publication No. 2019 / 202248, the applicant encountered a problem in which the viscosity of the oligomer solution increased excessively rapidly as soon as the degree of esterification reaction (evaluated by monitoring the disappearance of acidic functional groups) exceeded about 30%, that is, when about 30% of the number of carboxylic acid functional groups initially introduced had disappeared.

[0013] This excessively high viscosity of the binder composition results in excessive and cumbersome stickiness of the sizing mineral fiber mat in the mineral wool manufacturing process. After spraying the newly formed fibers with a relatively diluted aqueous sizing composition, the majority of the water evaporates naturally due to the high temperature of the fibers. When the sizing fibers are collected on a conveyor that leads them into the oven, their dry matter content is approximately 40-70%. Before entering the heated oven, the sizing fiber mat first passes under compression rollers and is then re-expanded by an airflow from below. The excessively high stickiness of the concentrated binder composition film results in, firstly, reduced re-expansion of the mat after (roller) compression, and secondly, difficulty in spreading the sizing composition to the contact points between mineral fibers and insufficient migration. The barrier product obtained after curing of the adhesive film has a higher density and inferior mechanical properties compared to equivalent barrier products obtained with a sizing composition of lower viscosity at a given solid content.

[0014] This invention is based on the discovery that partial replacement of one or more carbohydrate diols can significantly reduce the viscosity of aqueous oligoester compositions at predetermined conversion rates and dry matter content. This makes it possible to synthesize oligoesters with lower viscosity at predetermined conversion rates, or oligoesters with fewer free carboxylic acid functional groups at predetermined viscosity.

[0015] A higher conversion rate leads to a further reduction in acid decomposition products in the chimney flue gas and a lower crosslinking initiation temperature.

[0016] The first subject of the present invention is water and water-soluble oligomeric esters; - A carbohydrate comprising at least one carbohydrate selected from reducing sugars, non-reducing sugars, and hydrogenated sugars, wherein the hydrogenated sugar is selected from the group consisting of erythritol, arabitol, xylitol, sorbitol, mannitol, isitol, maltitol, isomaltitol, lactitol, cellobitol, palatinitol, maltotriitol, and hydrogenated starch hydrolysates or hydrolysates of lignocellulosic materials; -at least one diol; and - at least one polycarboxylic acid, water-soluble oligomer ester, A thermosetting binder composition comprising, The binder composition has a solid content of 40% to 80% by mass, preferably 40% to 70% by mass. The water-soluble oligomer ester accounts for at least 70% by mass of the solid content of the thermosetting binder composition. This is a thermosetting binder composition in which the ratio of the number of hydroxyl groups of the total diol to the total number of hydroxyl groups of the carbohydrate is 5% to 50%.

[0017] In this application, the term "carbohydrate" has a broader meaning than it usually does. The term refers to carbohydrates in the strict sense, i.e., formula C n (H2O) p This is because the formula includes not only reducing sugars or carbohydrates having at least one aldehyde or ketone group (reducing group), where p is n (monosaccharide) or p is n-1 (oligo and polysaccharide), but also hydrogenated versions of these carbohydrates in which the aldehyde or ketone group has been reduced to an alcohol. These hydrogenated versions are also called alditols, sugar alcohols, or hydrogenated sugars. The term "carbohydrate" also includes non-reducing sugars consisting of multiple carbohydrate units containing hemiacetal hydroxyl-carrying carbons involved in osidic bonds connecting the units.

[0018] In the present application, the terms "binder composition" and "sizing composition" are not synonymous. The term "binder composition" refers to a concentrated aqueous solution, i.e., a high solids content (tens of %). These compositions can be stored and transported. These compositions are rather fluid so that they can be pumped, but are too viscous to spray themselves onto the fibers. The term "sizing composition" refers to an aqueous solution having a solids content of less than 10% by mass and a substantially lower concentration. These are generally obtained by diluting the binder composition with water. Due to the sufficiently low viscosity, the sizing composition can be applied to the mineral wool fibers by spraying it through a nozzle onto the mineral wool fibers.

[0019] In principle, for the preparation of the thermosetting binder composition of the present invention, any of the carbohydrates selected from reducing sugars, non-reducing sugars and hydrogenated sugars can be used.

[0020] "Hydrogenated sugar" is intended to mean all products resulting from the reduction or hydrogenation of saccharides (carbohydrates) selected from monosaccharides, disaccharides, oligosaccharides, polysaccharides, and mixtures of these products. Hydrogenated sugars are also referred to as sugar alcohols, alditols or polyols. These can be obtained by the catalytic hydrogenation of saccharides. The hydrogenation can be carried out by known methods under conditions of high hydrogen pressure and high temperature in the presence of a catalyst selected from the elements of groups IB, IIB, IVB, VI, VII and VIII of the periodic table, preferably from the group comprising nickel, platinum, palladium, cobalt, molybdenum and mixtures thereof. A suitable catalyst is Raney nickel.

[0021] One or more hydrogenated sugars are selected from the group consisting of erythritol, arabitol, xylitol, sorbitol, mannitol, iditol, maltitol, isomaltitol, lactitol, cellobiitol, palatinite, maltotriitol, and hydrogenated products of starch hydrolyzates, or particularly hydrogenated products of hydrolyzates of lignocellulosic materials, especially hemicellulose, such as xylan and xyloglucan. Therefore, the hydrogenated sugars used in the present invention do not contain glycerol or polyglycerol.

[0022] The starch hydrolyzate is a product obtained by enzymatically and / or acid-hydrolyzing starch.

[0023] Before the hydrogenation step, a suitable starch hydrolyzate has a dextrose equivalent (DE) of 5 to 99, and 10 to 80 is advantageous.

[0024] Particularly preferably, a hydrogenated sugar selected from the group consisting of maltitol, xylitol, sorbitol, and hydrogenated products of hydrolyzates of starch or lignocellulosic materials is used.

[0025] Among the above-mentioned hydrogenated sugars, sorbitol is the most readily available and the lowest in price on the market. The applicant had aimed to develop a binder based on polycarboxylic acid and hydrogenated sugar during the test, but it was found that it was not easily possible to obtain a barrier product having sufficient mechanical properties (tensile breaking strength, thickness recovery, bending strength) when using this hydrogenated sugar as it was. To impart a predetermined mechanical strength to the obtained barrier product, it was necessary to significantly increase the polycarboxylic acid / sorbitol ratio of the sizing composition. However, this increase has three drawbacks: the corrosiveness of the sizing composition becomes stronger, the release of a large amount of acid decomposition products is promoted, and the efficiency of the binder line decreases (especially when the acid used is citric acid that thermally decomposes at less than 200°C).

[0026] According to the present invention, the aforementioned drawbacks regarding the use of sorbitol as a hydrogenated sugar can be prevented. Indeed, pre-oligomerization of sorbitol in an anhydrous medium in the presence of a polycarboxylic acid yields an oligoester having properties equivalent to, for example, xylitol or maltitol-based oligoesters.

[0027] From the above perspective, obtaining a barrier product based on mineral wool with sufficient mechanical properties naturally assumes that no free sorbitol is added to the binder composition after the esterification process. In other words, the advantage of the present invention, namely obtaining good mechanical properties even when sorbitol is used, will be negated if an excess amount of free sorbitol is added when preparing the sizing composition by diluting the binder composition of the present invention.

[0028] The binder composition and sizing composition of the present invention consequently contain less than 10% by mass, preferably less than 5% by mass, and more favorably less than 2% by mass, of free sorbitol that was added after the esterification step or remained unreacted during esterification. The proportion of this free sorbitol is relative to the total solid content of the binder composition or sizing composition of the present invention.

[0029] The reducing sugar is preferably selected from monosaccharides such as glucose, galactose, mannose, and fructose; disaccharides such as lactose, maltose, isomaltose, and cellobiose; and starch hydrolysates having a DE of 5 to 98, more preferably 15 to 95, and hydrolysates of lignocellulosic materials. Preferably, glucose or fructose is used, and glucose in particular.

[0030] The non-reducing sugar is preferably a disaccharide such as trehalose, isotrehalose, sucrose, or isosucrose. Sucrose is particularly preferred.

[0031] The one or more polycarboxylic acids used in this invention are monomeric polycarboxylic acids. In other words, in this invention, the term polycarboxylic acid does not refer to polymers obtained by polymerizing monomeric polycarboxylic acids, such as homopolymers or copolymers of acrylic acid or methacrylic acid.

[0032] Polycarboxylic acids selected from the group consisting of dicarboxylic acids, tricarboxylic acids, and tetracarboxylic acids are preferably used. Citric acid is a particularly preferred polycarboxylic acid.

[0033] The applicant conducted numerous tests to evaluate the proportions of carbohydrates and polycarboxylic acids that act as binders, which, when cross-linked, impart the best mechanical properties to the final product, particularly after accelerated aging under high humidity conditions.

[0034] These tests showed that the carbohydrate / citric acid weight ratio is favorably 20 / 80 to 55 / 45, and preferably 25 / 75 to 50 / 50.

[0035] Furthermore, the ratio of the total number of acid groups derived from the polycarboxylic acid to the total number of hydroxyl groups derived from one or more carbohydrates and one or more diols is favorably 30 / 70 to 70 / 30, preferably 35 / 60 to 60 / 40, and particularly 40 / 60 to 55 / 45.

[0036] To reduce the viscosity of the binder after application to the fibers and thus suppress the stickiness of the mat before curing, the diols used in the present invention are preferably linear or branched aliphatic diols, and therefore do not include either aromatic diols or alicyclic diols.

[0037] The diol is advantageously an aliphatic diol containing 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms. The alkyl chain may contain one or more oxygen atoms.

[0038] Particularly interesting examples of diols include those selected from the group consisting of ethylene glycol, propylene glycol, butanediol, hexanediol, diethylene glycol, and triethylene glycol.

[0039] The amount of one or more diols used should be such that the ratio of hydroxyl groups of the diols to the total number of hydroxyl groups of the diols and carbohydrates is between 5% and 50%. Below the lower limit of this range, the technical effects (limiting viscosity increase and reducing stickiness) become insufficient. Above the upper limit of this range, it certainly becomes difficult to obtain a satisfactory crosslinked binder. The introduction of diols (bifunctional compounds) into a citric acid and carbohydrate-based system effectively reduces the average functionality of the reaction system.

[0040] The ratio of the number of hydroxyl groups in the total diol used to the total number of hydroxyl groups in the total diol and carbohydrate is favorably between 8% and 40%, and preferably between 10% and 30%. These ratios are, of course, understood to refer to the diol and carbohydrate present in the reaction mixture before the esterification step is carried out for the synthesis of the oligoester.

[0041] A method for preparing the binder composition of the present invention comprises the steps of synthesizing an oligomer by esterifying a reagent in an essentially anhydrous medium, and then diluting the formed reaction product with water.

[0042] More specifically, the method for preparing the binder composition of the present invention is: - Heating a mixture of at least one carbohydrate selected from reducing sugars, non-reducing sugars and hydrogenated sugars, at least one diol, at least one polycarboxylic acid and optionally at least one esterification catalyst at 105 to 170°C, preferably 120 to 150°C, for 5 minutes to 10 hours, preferably 20 minutes to 5 hours, particularly 30 minutes to 2 hours, and - This includes adding a sufficient amount of water to obtain an aqueous solution of the oligomeric ester that can be pumped.

[0043] As described above, the reaction mixture for this bulk polycondensation is preferably essentially anhydrous, that is, preferably containing less than 2% water, and more preferably less than 1% water. In some cases, it may be necessary or permissible to add a small amount of water, generally less than 10% by mass, to homogenize the reagents in the reaction mixture. This water, necessary for homogenization, then evaporates due to heating.

[0044] A preferred embodiment of the method for synthesizing oligoesters includes heating a carbohydrate and a diol in the absence of a solvent until completely melted, and then adding citric acid and, optionally, a catalyst. The reaction time depends on the change in viscosity of the medium during the synthesis.

[0045] The progress of the oligomerization reaction can be monitored by the viscosity method as follows: A certain amount of the reaction medium is taken and diluted with distilled water to obtain a solution with a solid content equivalent to 60% (dry extract). This solution is introduced into an Anton Paar MCR302 rheometer (equipped with a 50 mm upper cone plate geometry and a 50 mm lower cone plate geometry) (which provides high sensitivity down to low viscosity). The viscosity of the oligomer is measured at room temperature with a shear rate of 5 seconds. -1 1000 seconds -1 After increasing it to 1000 seconds again -1 5 seconds -1 The viscosity is reduced and measured. It is found that the viscosity does not depend on the shear rate. The oligomeric solution is therefore a Newtonian liquid. Viscosity is measured at 20°C for 100 seconds. -1 The shear rate is stated as follows.

[0046] The objective of studying the oligomerization reaction dynamics is to find the best compromise between, on the one hand, an acceptable viscosity—that is, a viscosity low enough that the somewhat concentrated binder composition can still be pumped—and, on the other hand, the lowest possible crosslinking initiation temperature.

[0047] The crosslinking initiation temperature is evaluated using dynamic mechanical thermal analysis (DMTA), which allows for the characterization of the viscoelastic behavior of polymer materials. Two fiberglass strips are cut and overlapped. 30 mg of a 30% solids binder composition is uniformly deposited onto the strip and then fixed horizontally between the two jaws of an RSAIII apparatus (Texas Instruments). A vibrating element equipped with a device that measures stress as a function of applied deformation is placed on the upper surface of the specimen. This device allows for the evaluation of the modulus of elasticity E'. The specimen is heated from 20 to 250°C at a rate of 4°C / min. From the measurement results, a curve of the change in modulus of elasticity E' (MPa) as a function of temperature (°C) is plotted.

[0048] The DMTA curve is modeled using three line segments. (1) The tangent to the curve before the start of the reaction, (2) The slope of the line between the increase in elastic modulus during the reaction, (3) Tangent to the curve after the end of the increase in elastic modulus

[0049] The cross-linking initiation temperature (TR) is the temperature at the intersection of the first two straight lines.

[0050] When oligomerization reaches the desired degree, heating is stopped and water is added to the reaction mixture to obtain the binder composition of the present invention.

[0051] The binder composition of the present invention generally contains less than 25% by mass, preferably less than 20% by mass, of free residual polycarboxylic acid relative to the solid content. The other two monomers, carbohydrates and diols, are preferably present only in trace amounts, for example, less than 5% by mass, preferably less than 2% by mass.

[0052] The viscosity of the binder composition was measured at 20°C, with a 60% by mass dry matter content, using a rheometer (Anton Paar MCR302 rheometer, with a 50mm upper cone plate geometry and a 50mm lower cone plate geometry, at a shear rate of 100 seconds). -1The viscosity of the binder composition is evaluated using ), and is 50-250 mPa·s, preferably 60-200 mPa·s, and particularly 70-180 mPa·s.

[0053] The oligomerization is carried out in the presence of a known esterification catalyst selected from a strong acid such as sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, or trifluoroacetic acid, and a Lewis acid commonly used as a catalyst for esterification reactions.

[0054] When using citric acid, the oligomerization reaction may also be catalyzed with sodium hypophosphite. Although this is not strictly an esterification catalyst, it is thought to be more reactive than triacids and to promote the formation of citrate anhydride that can react with polyols (carbohydrates and diols).

[0055] Therefore, one or the other of these two types of catalysts will be present in the thermosetting binder composition.

[0056] When an esterification catalyst such as a strong acid is used as a catalyst for the oligomerization reaction, it is desirable to add an effective amount of sodium hypophosphite or hypophosphorous acid to the binder composition before or after dilution with water to obtain the sizing composition, for example, the amount being 0.5 to 10% by mass, preferably 1.0 to 5% by mass, relative to the mass of the solid content of the binder composition. Sodium hypophosphite and the corresponding acid are, in fact, currently the compounds that most effectively catalyze the curing of oligomers into a thermosetting binder (which is insoluble in water).

[0057] The binder composition of the present invention is required to be storable and transportable. In other words, it is required to be stable when stored at room temperature and not undergo substantial hydrolysis that converts the oligoester into a polyol and polyacid even when a relatively large amount of water, which may be in the range of 20 to 60% by mass, is present.

[0058] The applicant found that good storage stability of the composition was obtained at a neutral or acidic pH, preferably 1 to 7, more preferably 3 to 6.

[0059] This application also relates to a method for producing products based on mineral fibers or organic fibers bound together by an insoluble organic binder, using the binder composition according to the above invention.

[0060] The above method includes the following sequential steps: (a) Prepare a sizing composition by diluting the above thermosetting binder composition with water to a solid content of 2 to 10% by mass. (b) Apply the sizing composition to mineral fibers or organic fibers (c) forming aggregates of sized mineral fibers or organic fibers, and (d) Heat the resulting sized mineral fiber or organic fiber aggregate until the sizing composition hardens.

[0061] To obtain a high-quality product, the sizing composition must have good sprayability and be able to deposit as a thin film on the surface of the fibers so that the fibers are effectively bonded. The sprayability of the sizing composition is directly related to the ability to dilute the concentrated binder composition with a large amount of water. The diluted sizing composition is required to be a time-stable solution that does not undergo demixing.

[0062] Dilution suitability is characterized by “dilutability,” defined as the volume of deionized water that can be added to a given volume unit of the binder composition before permanent haze appears at a given temperature. A binder composition is generally considered suitable for sizing when its dilutability is equal to or greater than 1000% at 20°C.

[0063] The binder composition of the present invention has a dilution ratio greater than 2000%.

[0064] It is certainly conceivable that the method for producing mineral fiber or organic fiber-based products of the present invention may be carried out by directly diluting an aqueous sizing composition from oligomerized products obtained by bulk esterification of polyacids and carbohydrates, without preparing a concentrated intermediate solution (binder composition). This variation of the method may be useful when the synthesis of oligomer esters is carried out in the same location as the production of the final mineral fiber or organic fiber-based product. The method is considered to be entirely equivalent to one that includes the preparation of an intermediate concentrate intended for storage and / or transport.

[0065] The process of preparing the sizing composition is advantageous to include the addition of one or more known additives commonly used in the art of mineral wool. These additives are selected from, for example, dustproofing additives, silicones, and coupling agents.

[0066] In a particularly preferred embodiment of the method of the present invention, it is avoided to add large amounts of monomers that can react with oligoesters, such as reducing sugars, non-reducing sugars, hydrogenated sugars, or other polyols, or amines, especially alkanolamines, to the binder composition.

[0067] When applied to mineral fibers or organic fibers, the sizing composition preferably contains at least 70% by mass, more preferably at least 75% by mass, or even further at least 80% by mass, of the total solids content of a water-soluble oligomer ester.

[0068] In an advantageous embodiment of the method of the present invention, the fibers are mineral fibers, and the aggregate of fibers is mineral wool.

[0069] A sizing composition is applied to mineral fibers in a known manner through nozzles positioned in a spray ring near a molten glass extruder.

[0070] Next, the sized mineral fibers are assembled into a mat (or loft) shape on a conveyor belt that passes through the oven.

[0071] For crosslinking of the binder, it is advantageous to heat an assembly of sized mineral fibers at 180 - 230°C for 20 seconds to 5 minutes, preferably 30 seconds to 3 minutes. Example 1

[0072] 116.1 g of sorbitol and 57.4 g of butanediol (molar ratio of OH butanediol / OH sorbitol = 0.25) are introduced into a reactor and heated at a temperature of 130°C. Then, 326.5 g of citric acid (powder) is added in portions. The reagents are reacted by stirring the reaction mixture at 130°C for as long as necessary to obtain the desired conversion rate. The water formed is removed by vacuum distillation. When the conversion rate is reached, heating is stopped and water is added to the reaction medium containing the formed oligomers to obtain a dry matter content of 60%.

[0073] This protocol is repeated using only 154.6 g of sorbitol. (Comparative test without butanediol)

[0074] Another series of tests is carried out using 139.3 g of sorbitol and 23.0 g of butanediol. (molar ratio of OH butanediol / OH sorbitol = 0.10)

[0075] The conversion rate of the oligomerization reaction (esterification) is followed by acid-base titration. A defined quantity (approx. 1.0 g) of the reaction medium is taken and diluted with distilled water to obtain a solution with a dry matter content of approx. 1%.

[0076] The number of residual acid functional groups in the taken defined quantity is given by pH measurement using an automatic titrator (addition of 0.1 N sodium hydroxide). And the number of residual acid functional groups in the reaction product is calculated.

[0077] The conversion rate is calculated using the following formula. Conversion (%) = 100(n COOH - nresidual) / n COOH ·······n COOH = Initial number of carboxylic acid functional groups n = number of residual carboxylic acid functional groups

[0078] The viscosity of the reaction product diluted to 60% dry matter content is evaluated using an Anton Paar MCR302 rheometer (equipped with a 50 mm upper cone plate geometry and a 50 mm lower cone plate geometry) (which provides high sensitivity down to low viscosity). The viscosity of the oligomer is measured at room temperature with a shear rate of 5 seconds. -1 1000 seconds -1 After increasing it to 1000 seconds again -1 5 seconds -1 It is reduced to this value and measured. Viscosity is found to be independent of shear rate. The oligomeric solution is therefore a Newtonian liquid. 100 seconds at 20°C. -1 The viscosity measured at the shear rate is shown in Table 1 below. [Table 1]

[0079] At a given conversion rate, the viscosity of the binder composition (evaluated at 20°C and 60% dry matter content) decreases when some of the sorbitol is replaced with butanediol. For example, a binder composition prepared from sorbitol and citric acid with a conversion rate of 38% has a viscosity of 95 mPa·s. When some of the sorbitol is replaced with butanediol (OH butanediol / OH sorbitol = 10%), the viscosity is 81.3 mPa·s, and when some of the sorbitol is replaced with butanediol (OH butanediol / OH sorbitol = 25%), the viscosity decreases to 35 mPa·s.

[0080] It has also been observed that when 25% of the hydroxyl functional groups generated by sorbitol are replaced by hydroxyl functional groups generated by butanediol, it becomes possible to obtain a binder composition with a conversion rate greater than 40 (42-55%) and a viscosity that is completely acceptable (71-139 mPa·s). This disclosure includes the following embodiments of the invention: <Aspect 1> A thermosetting binder composition comprising water and a water-soluble oligomer ester, This water-soluble oligomer ester is - A carbohydrate comprising at least one carbohydrate selected from reducing sugars, non-reducing sugars, and hydrogenated sugars, wherein the hydrogenated sugar is selected from the group consisting of erythritol, arabitol, xylitol, sorbitol, mannitol, isitol, maltitol, isomaltitol, lactitol, cellobitol, palatinitol, maltotriitol, and hydrogenated starch hydrolysates or hydrolysates of lignocellulosic materials; -at least one diol; and - at least one polycarboxylic acid, It is a water-soluble oligomer ester, The binder composition has a solid content of 40% to 70% by mass. The water-soluble oligomer ester accounts for at least 70% by mass of the solid content of the thermosetting binder composition. A thermosetting binder composition in which the ratio of the number of hydroxyl groups of the total diol to the total number of hydroxyl groups of the carbohydrate is 5% to 50%. <Aspect 2> The binder composition according to Embodiment 1, characterized in that the ratio of the number of hydroxyl groups of the total diol to the total number of hydroxyl groups of the carbohydrate is 8% to 40%, preferably 10% to 30%. <Aspect 3> The aforementioned diol is C 2 ~C 12 an aliphatic diol, preferably C 2 ~C 8 The binder composition according to embodiment 1 or 2, characterized in that it is linear or branched and optionally contains one or more oxygen atoms in the alkyl chain. <Aspect 4> The binder composition according to embodiment 3, characterized in that the diol is selected from the group consisting of ethylene glycol, propylene glycol, butanediol, hexanediol, diethylene glycol, and triethylene glycol. <Aspect 5> A thermosetting binder composition according to any one of embodiments 1 to 4, characterized in that it contains less than 10% by mass, particularly less than 5% by mass, of free sorbitol relative to the solid content. <Aspect 6> A thermosetting binder composition according to any one of embodiments 1 to 5, characterized in that the reducing sugar is selected from monosaccharides, disaccharides, starch hydrolysates having a dextrose equivalent (DE) of 5 to 98, preferably 15 to 95, and hydrolysates of lignocellulose-based materials. <Aspect 7> A thermosetting binder composition according to any one of embodiments 1 to 6, characterized in that the hydrogenated sugar is selected from the group consisting of xylitol, maltitol, sorbitol, and hydrogenated starch hydrolysates or hydrolysates of lignocellulosic materials. <Aspect 8> A thermosetting binder composition according to any one of embodiments 1 to 7, characterized in that the one or more polycarboxylic acids are selected from dicarboxylic acids, tricarboxylic acids, and tetracarboxylic acids. <Pattern 9> The binder composition according to any one of embodiments 1 to 8, characterized in that the polycarboxylic acid is citric acid. <Aspect 10> The binder composition according to embodiment 9, characterized in that the ratio of the total number of acid groups produced by the polycarboxylic acid to the total number of hydroxyl groups produced by the one or more carbohydrates and the one or more diols is 30 / 70 to 70 / 30, preferably 35 / 60 to 60 / 40, and particularly 40 / 60 to 55 / 45. <Aspect 11> A binder composition according to any one of embodiments 1 to 10, characterized in that it contains less than 25% by mass, preferably less than 20% by mass, of free residual polycarboxylic acid relative to the solid content. <Aspect 12> The binder composition according to embodiment 9, further comprising sodium hypophosphite and hypophosphorous acid. <Aspect 13> A method for producing mineral fibers bound with an organic binder or a product based on organic fibers, wherein the method is: (a) Prepare a sizing composition by diluting the thermosetting binder composition described in any of embodiments 1 to 12 with water to a solid content of 2 to 10% by mass. (b) Applying the sizing composition to mineral fibers or organic fibers, (c) forming aggregates of sized mineral fibers or organic fibers, and (d) Heat the aggregate of sized mineral fibers or organic fibers until the sizing composition hardens. Methods that include... <Aspect 14> The method according to embodiment 13, characterized in that step (a) of preparing the sizing composition includes adding one or more additives, preferably selected from dust-proofing additives, silicones, and coupling agents. <Aspect 15> The method according to embodiment 13 or 14, characterized in that the fibers are mineral fibers and the aggregate of the fibers is mineral wool. <Aspect 16> The method according to any one of embodiments 13 to 15, characterized in that when the sizing composition is applied to the mineral fiber or organic fiber, the sizing composition contains less than 10% by mass, preferably less than 5% by mass, of free sorbitol relative to the solid content.

Claims

1. A thermosetting binder composition comprising water and a water-soluble oligomer ester, This water-soluble oligomer ester is - A carbohydrate comprising at least one carbohydrate selected from reducing sugars, non-reducing sugars, and hydrogenated sugars, wherein the hydrogenated sugar is selected from the group consisting of erythritol, arabitol, xylitol, sorbitol, mannitol, isitol, maltitol, isomaltitol, lactitol, cellobitol, palatinitol, maltotriitol, and hydrogenated starch hydrolysates or hydrolysates of lignocellulosic materials; - at least one diol; and - At least one polycarboxylic acid, It is a water-soluble oligomer ester, The binder composition has a solid content of 40% to 70% by mass. The water-soluble oligomer ester accounts for at least 70% by mass of the solid content of the thermosetting binder composition. A thermosetting binder composition in which the ratio of the number of hydroxyl groups of the total diol to the total number of hydroxyl groups of the carbohydrate is 5% to 50%.

2. The binder composition according to claim 1, characterized in that the ratio of the number of hydroxyl groups of the total diol to the total number of hydroxyl groups of the carbohydrate is 8% to 40%.

3. The diol is a straight-chain or branched C ２ ~C １２ The binder composition according to claim 1 or 2, characterized in that it is an aliphatic diol, and optionally contains one or more oxygen atoms in the alkyl chain.

4. The binder composition according to claim 3, characterized in that the diol is selected from the group consisting of ethylene glycol, propylene glycol, butanediol, hexanediol, diethylene glycol, and triethylene glycol.

5. A thermosetting binder composition according to any one of claims 1 to 4, characterized in that it contains less than 10% by mass of free sorbitol relative to the solid content.

6. The thermosetting binder composition according to any one of claims 1 to 5, characterized in that the reducing sugar is selected from monosaccharides, disaccharides, starch hydrolysates having a dextrose equivalent (DE) of 5 to 98, and hydrolysates of lignocellulosic materials.

7. The thermosetting binder composition according to any one of claims 1 to 6, characterized in that the hydrogenated sugar is selected from the group consisting of xylitol, maltitol, sorbitol, and hydrogenated starch hydrolysates or hydrolysates of lignocellulosic materials.

8. The thermosetting binder composition according to any one of claims 1 to 7, characterized in that the one or more polycarboxylic acids are selected from dicarboxylic acids, tricarboxylic acids, and tetracarboxylic acids.

9. The binder composition according to any one of claims 1 to 8, characterized in that the polycarboxylic acid is citric acid.

10. The binder composition according to claim 9, characterized in that the ratio of the total number of acid groups produced by the polycarboxylic acid to the total number of hydroxyl groups produced by the one or more carbohydrates and the one or more diols is 30 / 70 to 70 / 30.

11. A binder composition according to any one of claims 1 to 10, characterized in that it contains less than 25% by mass of free residual polycarboxylic acid relative to the solid content.

12. The binder composition according to claim 9, further comprising sodium hypophosphite and hypophosphorous acid.

13. A method for producing mineral fibers bound with an organic binder or a product based on organic fibers, wherein the method is: (a) A sizing composition is prepared by diluting the thermosetting binder composition according to any one of claims 1 to 12 with water to a solid content of 2 to 10% by mass. (b) Applying the sizing composition to mineral fibers or organic fibers, (c) forming aggregates of sized mineral fibers or organic fibers, and (d) Heating the aggregate of sized mineral fibers or organic fibers until the sizing composition hardens. Methods that include...

14. The method according to claim 13, characterized in that step (a) of preparing a sizing composition includes adding one or more additives.

15. The method according to claim 13 or 14, characterized in that the fibers are mineral fibers and the aggregate of the fibers is mineral wool.

16. The method according to any one of claims 13 to 15, characterized in that when the sizing composition is applied to the mineral fiber or organic fiber, the sizing composition contains less than 10% by mass of free sorbitol relative to the solid content.

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