Method for recycling a mineral fiber material, use of a solution for decomposing the binder of said material, and oligomers obtained

Abstract

The present invention relates to a method for recycling a material in the form of a web, mat, or felt of mineral fibers bonded by a binder comprising at least one thermosetting resin, said method comprising a step of bringing said material into contact with at least one amine dissolved in an aprotic polar solvent, at a temperature of at least 50°C for a period of time sufficient to decompose said binder. The invention further relates to the use of a solution comprising such an amine and such an aprotic polar solvent to decompose such a binder comprised in such a material. Finally, the invention relates to an oligomer obtainable by such a method.

Description

[0001] Description

[0002] Title of the invention: Process for recycling a mineral fiber material, using a solution to decompose the binder of this material and oligomers obtained

[0003] technical field

[0004] [1] The present invention relates to the field of materials in the form of veils, mattresses, or felts of mineral fibers, particularly in the form of mineral wool, bonded with a binder comprising at least one thermosetting resin. More particularly, the invention relates to a process comprising a step of bringing said material into contact with at least one amine in solution in a polar aprotic solvent, at a temperature of at least 50 °C for a sufficient time to decompose the binder.

[0005] Background of the invention

[0006] [2] The use of mineral fibre-based materials, in particular glass wool and glass fibre veils, has become widespread in the field of construction, particularly to meet regulatory requirements aimed at reducing the energy consumption of buildings and their environmental impact.

[0007] [3] Mineral wool-based materials are used as thermal or acoustic insulation, while mineral fibre veils can be used in particular as wall coverings, surfacing materials or support layers for thermal or acoustic insulation products.

[0008] [4]Alternatively, mineral fibre veils can be used to manufacture shingles or waterproofing membranes for terraces or bituminous roofs.

[0009] [5] Mineral wool mattresses used as insulation have a certain lifespan and it may be necessary to change the substrate on which they are applied, particularly in the context of the renovation or transformation of a building or to replace them with more efficient insulating materials; this may also be the case for production waste (such as cutting waste).

[0010] [6]For their part, mineral fibre webs generate waste, particularly at the output of production (cutting waste), during a manufacturing cycle or during transitions in their production process (non-conforming webs, typically first and last webs of the cycle).

[0011] [7] Currently, these materials are either landfilled or destroyed by incineration. It is also possible to remelt the glass. In this latter case, the resulting glass must then undergo a fiber-making process if it is to be reused.

[0012] [8]Furthermore, all these materials contain, in addition to mineral fibers, a binder intended to ensure the cohesion of the fibers between them and to give the material the desired mechanical properties.

[0013] [9] In the event of glass remelting, it is therefore necessary to first remove the binder by combustion or pyrolysis. In the case of urea-formaldehyde or phenol-urea-formaldehyde-based binders, combustion and pyrolysis processes generate pollutants such as nitrogen gases and / or sulfur oxides (SO₂). X ) which must be reprocessed. Their burial also entails a risk of soil pollution.

[0014]

[0010] These processes therefore have a significant environmental and economic impact, particularly given their energy balance. It would therefore be desirable to have a more environmentally friendly process for recycling these materials, that is to say, for recovering their constituents, in particular the glass fibers and the binder.

[0015]

[0011] In this context, the inventors have developed a simple process for decomposing the binder by aminolysis at a moderate temperature, while preserving the fiber structure, thus eliminating the need for the melting and fiber-pulling steps previously used. The process according to the invention therefore makes it possible to recycle insulating materials under economically acceptable and more environmentally favorable conditions, since the energy balance of the process is improved compared to current recycling processes.

[0016]

[0012] It has already been suggested in US application 2019 / 0241713 to recycle a composite material based on a matrix formed from a phenolic resin incorporating glass fiber reinforcements. In this process, the composite material undergoes an aminolysis step to recover, on the one hand, monomers or oligomers capable of reforming a resin and, on the other hand, the mineral fibers. However, it is not suggested that this process could be applied to products other than these composites, which are in the form of laminates formed from a stack of glass fiber fabrics impregnated with phenolic resin, primarily intended for the manufacture of aeronautical or automotive parts, and in particular that this process could be used in the recycling of materials containing predominantly mineral fibers.

[0017]

[0013] Furthermore, the process implemented in US 2019 / 0241713 includes a final separation / purification step by distillation, which necessarily makes it unsuitable for amines with a high boiling point, for example, above 100 °C. Moreover, because of this step, this process is also unsuitable for the recovery of oligomers that are likely to re-polymerize under the effect of heat.

[0018]

[0014] The inventors have developed an aminolysis process that enables a different separation / purification through the use of specific amines and solvents. These amines have high boiling points and were therefore incompatible with known prior art processes.

[0019]

[0015] Compared to the prior art, the process according to the invention allows for recycling without the need for distillation through the use of inexpensive, non-toxic, and environmentally friendly compounds. The invention therefore enables recycling that is even less energy-intensive than existing solutions.

[0020] Summary of the invention

[0021]

[0016] The present invention thus relates to a process for recycling a material in the form of a veil, mattress, or felt made of mineral fibers, particularly mineral wool, bonded with a binder comprising at least one thermosetting resin. The process includes a step of bringing the material into contact with at least one amine in solution in a polar aprotic solvent, at a temperature of at least 50 °C, in particular at least 80 °C, and preferably at least 100 °C, for a sufficient duration to decompose the binder. Detailed description

[0022]

[0017] The present invention relates to a method for recycling a material originating, for example, from the collection of waste from renovation or demolition sites, or from factory waste, or from waste from a production line.

[0023]

[0018] By “recycling process” we mean a material treatment process which allows the constituents of the material to be recovered, in particular the mineral fibers it contains, possibly to be reused in the manufacture of a new material, but also to recover the binder in the form of oligomers or monomers.

[0024]

[0019] This material can be a veil of mineral fibers or a mattress or a mineral wool felt.

[0025]

[0020] In the context of this description, "mineral wool" means a mass of intertwined, discontinuous mineral fibers of varying lengths. The air pockets between the fibers give the material formed from mineral wool thermal and / or acoustic insulation properties. It is therefore an insulating material.

[0026]

[0021] By "insulating material" is meant a material that limits heat exchange between two surfaces it separates and that is characterized by a thermal conductivity α of less than 0.05 W / mK and generally greater than 0.02 W / mK. It is in the form of a mat or felt with a nominal thickness generally ranging from 10 to 400 mm, for example from 15 to 350 mm, preferably from 20 to 300 mm. Its density is preferably between 2 and 220 kg / m³ 3 , in particular from 5 to 180 kg / m 3 preferably between 10 and

[0027] 100 kg / m 3and more preferably between 10 and 60 kg / m 3 Mineral fibers typically make up 80 to 99% of the weight of the insulating material.

[0028]

[0022] By "nominal thickness" is meant the thickness of mattresses or felts as they are marketed, in compressed or uncompressed form.

[0029]

[0023] The manufacture of mineral wool insulation products generally includes a step of manufacturing the wool itself, which can be carried out by various processes, for example, according to known techniques of internal or external centrifugal spinning. Centrifugation consists of introducing molten mineral material (glass or rock) into a centrifugal device, comprising, for example in the case of glass, a multitude of small orifices. The material is projected towards the peripheral wall of the device under the action of centrifugal force and escapes in the form of filaments. At the exit of the centrifugal device, the filaments are stretched and carried towards a receiving element by a gas stream having a high temperature and speed, to form a sheet of fibers (or mineral wool).

[0030]

[0024] To ensure the bonding of the fibers and to give the web cohesion, a sizing composition in the form of an aqueous solution containing a thermosetting resin is sprayed onto the fibers along the path from the outlet of the centrifugal device to the receiving element. The sizing-coated fiber web is then subjected to heat treatment, generally at a temperature above 100 °C, to induce polycondensation of the resin and thus obtain a thermal and / or acoustic insulation product with specific properties, including dimensional stability, tensile strength, thickness recovery after compression, and a homogeneous color.

[0031]

[0025] In the context of this description, "mineral fiber veil" means a non-woven material based on mineral fibers, the thickness of which is generally less than or equal to 2 mm, preferably less than or equal to 1 mm, and generally between 250 and 1000 µm. Its surface mass is generally between 20 and 500 g / m². 2 , preferably from 30 to 250 g / m 2 , for example from 30 to 120 g / m 2 or 150 to 250 g / m 2 .

[0032]

[0026] Mineral fibers can be filaments or yarns composed of a multitude of filaments and assemblies of such yarns.

[0033]

[0027] Thus, according to a first embodiment, the mineral fiber veil is composed of mineral filaments of length up to 150 mm, preferably from 1 to 100 mm and advantageously from 2 to 50 mm, and having a diameter which can vary to a large extent, for example from 5 to 30 pm.

[0034]

[0028] According to a second embodiment, the mineral fiber veil is composed of mineral yarns. The mineral yarns may be yarns composed of a multitude of mineral filaments (or base yarns) or assemblies of these base yarns in rovings. The aforementioned yarns may be untwisted or twisted yarns (or textile yarns), preferably untwisted. The mineral yarns, particularly glass yarns, are generally cut to a length of up to 100 mm, preferably from 6 to 40 mm, and in particular from 10 to 35 mm. The diameter of the glass filaments constituting the yarns may vary widely, for example from 5 to 30 µm. Similarly, wide variations may occur in the linear density of the yarn, which may range from 34 to 1500 tex. The glass constituting the filaments may be of any type, for example C, E, R, ECR, or AR (alkali-resistant). We prefer glass C or E.

[0035]

[0029] In one embodiment, the nonwoven fabric can further be reinforced by a network of mineral fibers, in particular twisted or untwisted glass fibers, preferably arranged parallel to each other. Each fiber is composed of a multitude of very fine filaments. These mineral fibers are generally deposited on the fabric conveying device in the direction of the fabric's movement and distributed over all or part of the width of the mat. They are preferably deposited between two layers of mineral fibers.

[0036]

[0030] In one embodiment, the non-woven veil therefore comprises mineral fibers, in particular glass fibers, arranged parallel to each other, and preferably in the machine direction, between two layers of randomly arranged mineral fibers.

[0037]

[0031] Mineral fibre veils can be manufactured according to known processes operating by dry or wet method.

[0038]

[0032] In the dry process, molten material contained in a furnace is conveyed to a set of dies from which filaments flow by gravity and are drawn out by a gas flow. The filaments are collected on a conveyor where they intertwine.

[0039]

[0033] On the upper surface of the material thus formed, a sizing composition containing at least one thermosetting resin is applied using a suitable device, most often operating by curtain deposition, and the excess sizing composition is removed by suction from the opposite surface. The material then enters a hot air oven whose temperature is adapted to remove the water and crosslink the resin in a sufficiently short time, and the resulting mineral fiber web is then collected and wound up.

[0040]

[0034] In the wet process, the web is obtained from an aqueous dispersion of chopped mineral fibers which is deposited by means of a forming head onto a conveyor equipped with perforations, and the water is extracted through the conveyor by means of a suction box. The chopped fibers remaining on the conveyor form a web which is processed under the same conditions as those described for the dry process.

[0041]

[0035] The mineral fibers constituting the mineral wool or the mineral fiber veil can be made of glass or rock fibers or a mixture of glass and rock fibers.

[0042]

[0036] Glass fibers can be of any type.

[0043] [37JI1 may therefore be biosoluble fibers as described in application WO 2022 / 229571 A1, having the following composition, expressed as mass content relative to the total mass of the fibers:

[0044] SiO2: 50 to 75%, preferably 60 to 70%

[0045] Na2O: 10 to 25%, preferably 10 to 20%

[0046] CaO: 5 to 15%, preferably 5 to 10%

[0047] MgO: 1 to 10%, preferably 2 to 5%

[0048] CaO and MgO together preferably represent 5 to 20%

[0049] B2O3: 0 to 10%, preferably 2 to 8%

[0050] Al2O3: 0 to 8%, preferably 1 to 6%

[0051] K2O: 0 to 5%, preferably 0.5 to 2%

[0052] Na2O and K2O together preferably represent 12 to 20%

[0053] Iron oxide: 0 to 3%, preferably less than 2%, preferably even less than 1%

[0054] other oxide(s): from 0 to 5% cumulatively, preferably less than 3% cumulatively,

[0055] the rest being made up of unavoidable impurities.

[0056]

[0038] Alternatively, the glass fibers may be high alumina fibers, typically having the following composition, expressed as mass contents relative to the total mass of the fibers:

[0057] SiO2: 30 to 50%, preferably 35 to 45%

[0058] Na2O: from 0 to 20%, preferably from 0.4 to 7%

[0059] CaO: 6 to 35%, preferably 12 to 25%

[0060] MgO: 1 to 15%, preferably 5 to 13%

[0061] CaO+MgO: from 11 to 40% cumulatively,

[0062] Al2O3: from 10 to 27%

[0063] K2O: 0 to 15%, preferably 0 to 1%

[0064] Iron oxide: 0.5 to 15%, preferably 3 to 12%, other oxide(s): 0 to 5% cumulative, preferably less than 3% cumulative.

[0065] the rest being made up of unavoidable impurities.

[0066]

[0039] Apart from the mineral fibers, the material used according to the invention contains a binder comprising at least one thermosetting resin, that is to say, a cross-linked, insoluble, and infusible polymeric system. The binder can be obtained by hardening a sizing composition, which consists of an aqueous solution containing a mixture of organic and possibly inorganic compounds (sometimes referred to as "resin") capable of reacting with each other at high temperatures.

[0067]

[0040] In one embodiment of the invention, the thermosetting resin is a phenolic resin.

[0068]

[0041] The phenolic resins usable according to the present invention include both novolac resins and resols, both of which are obtained by reaction of formaldehyde, and possibly another aldehyde, with phenol and possibly o-, p- and / or m-cresol.

[0069]

[0042] The resins are prepared using an excess of formaldehyde under basic conditions, the formaldehyde / phenol molar ratio typically being between 2 and 4, each phenol molecule potentially being able to react with three formaldehyde molecules. They contain numerous methylol groups attached to an aromatic ring, which constitute the crosslinking sites by dehydration / formaldehyde release. These resins are essentially composed of phenol / formaldehyde condensates (PF), residual phenol, and residual formaldehyde.

[0070]

[0043] Novolac resins, on the other hand, are obtained by acid catalysis, using a sub-stoichiometric amount of formaldehyde. Novolac resins require the use of a crosslinking agent, such as a polyamine, to form a thermosetting resin.

[0071]

[0044] According to the invention, it is preferable to use phenolic resins of the resol type, possibly modified with an amine, preferably a monoalkanolamine, and in particular monoethanolamine.

[0072] This alkanolamine reacts via the Mannich reaction with phenol / formaldehyde (PF) condensates, phenol, and formaldehyde to form phenol / formaldehyde / amine (PFA) condensates. This amine-based phenolic resin consists essentially of phenol-formaldehyde and phenol-formaldehyde-amine condensates. Resins of this type are described, in particular, in application WO 2008 / 043961.

[0073]

[0045] In one embodiment of the invention, the binder comprises a phenolic resin optionally modified with an amine or with urea, in particular an amine-modified phenolic resin consisting essentially of phenol-formaldehyde condensates and phenol-formaldehyde-amine condensates or consisting essentially of phenol-formaldehyde condensates and phenol-formaldehyde-urea condensates.

[0074]

[0046] In another embodiment of the invention, the binder comprises a urea-formaldehyde resin or a melamine-formaldehyde resin, preferably a urea-formaldehyde resin.

[0075]

[0047] This embodiment is particularly well suited to mineral fibre veils.

[0076]

[0048] In the case where it constitutes a web of mineral fibers, the material used according to the invention advantageously contains from 60 to 95% by weight of mineral fibers, and preferably from 65 to 90% by weight of mineral fibers, for example from 75 to 85% by weight of mineral fibers, relative to the dry weight of the web. It advantageously contains from 5 to 40% by weight of binder, preferably from 10 to 35% by weight of binder, for example from 15 to 25% by weight of binder, relative to the dry weight of the web. In one embodiment of the invention, the weight ratio of fibers to binder is from 3:1 to 5:1.

[0077]

[0049] In the case where this material is a felt or a mineral wool mattress, the mineral fibers can represent from 80 to 99% of the weight of the material.

[0078]

[0050] Thus, the material used in a process according to the invention can comprise from 60 to 99% by weight of mineral fibers, preferably from 65 to 99% by weight of mineral fibers, for example from 75 to 99% by weight of mineral fibers, relative to the total weight of the material.

[0079]

[0051] When the binder consists solely of combustible organic components, this binder content is identical to what is usually called loss on ignition (LOI, from the English "loss on ignition").

[0080]

[0052] The binder may, however, contain a certain fraction of mineral components, for example, mineral particulate fillers. This fraction generally does not exceed 20% by weight of the binder. When the binder contains such a mineral filler, its loss on ignition (LOI) will therefore be lower than the binder content of the nonwoven mineral fiber web.

[0081]

[0053] In a preferred embodiment of the invention, the material used is in the form of a veil of mineral fibers bonded with a binder comprising a urea-formaldehyde resin or a melamine-formaldehyde resin, preferably a urea-formaldehyde resin, or is in the form of a mattress or felt of mineral wool containing mineral fibers which represent 80 to 99% by weight of the total weight of the material.

[0082]

[0054] In the process according to the present invention, an insulating material comprising a binder as described above is reacted with at least one amine.

[0083]

[0055] The amine used in the process according to the invention is advantageously soluble in water at 25 °C, in particular the solubility of the amine in water at 25 °C is at least 60 g / L and preferably at least 100 g / L.

[0084]

[0056] The amine used in the process according to the invention advantageously has a boiling point of at least 50 °C, in particular of at least 80 °C, and preferably of at least 100 °C.

[0085]

[0057] In particular, the amine used in the process according to the invention is chosen from primary or secondary hydrocarbon mono- or polyamines, saturated or unsaturated, linear, branched or cyclic, optionally aromatic, whose hydrocarbon chain contains from 1 to 20 carbon atoms and can optionally be substituted by at least one group chosen from hydroxyl and aromatic groups and / or interrupted by at least one oxygen atom; and mixtures thereof.

[0086]

[0058] In a preferred embodiment of the invention, the amine is chosen from saturated primary or secondary amines substituted by at least one group chosen from hydroxyl and aromatic groups; and mixtures thereof.

[0087]

[0059] In a particularly preferred manner, the amine is chosen from among the saturated primary or secondary amines substituted by at least one hydroxyl group.

[0088]

[0060] According to the invention, a monoamine is preferred, in particular selected from aminopropanol, 2-aminopropanol, 2-(methylamino)ethanol, benzylamine, and mixtures thereof; in particular, the amine is selected from aminopropanol, 2-aminopropanol, 2-(methylamino)ethanol, and mixtures thereof; preferably, the amine is selected from aminopropanol, 2-(methylamino)ethanol, and mixtures thereof.

[0061] For the purposes of the invention, the term "amine" refers to both a single amine and a mixture of amines.

[0089]

[0062] The material is brought into contact with the amine by immersing the material in a solution containing the amine in a polar aprotic solvent.

[0090]

[0063] When the material is brought into contact, it is preferably in a divided form, obtained by a comminution step, for example implemented by grinding the initial material or by stirring the solution in which the material is immersed.

[0091]

[0064] Thus, in a particular embodiment, the process according to the invention includes, prior to or concurrently with the step of bringing the material into contact with the amine, a step of comminution of the material.

[0092]

[0065] In a particular embodiment, the amine represents from 2% to 30% of the volume, in particular from 5% to 25% of the volume and preferably from 7% to 15% of the volume, relative to the total volume of solution.

[0093]

[0066] In a particular embodiment, the aprotic polar solvent is chosen from dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), hexamethylphosphoramide (HMPA), N,N'-dimethylpropylene urea (DMPU), and mixtures thereof; in particular the solvent is chosen from DMSO, DMF, and mixtures thereof; preferably the solvent is DMSO.

[0094]

[0067] The material is brought into contact with the amine at a temperature of at least 50 °C.

[0095]

[0068] Preferably, the material is brought into contact with the amine at a temperature of at least 100 °C.

[0096]

[0069] In a particular embodiment, this contact is made at a temperature between 50 °C and 300 °C, in particular from 75 °C to 250 °C, and preferably from 100 °C to 200 °C.

[0097]

[0070] It is preferably carried out at the boiling point of the amine, or in the case of the use of several amines, at the highest boiling point among the boiling points of the amines used.

[0098]

[0071] This contact can last for a period ranging, for example, from 1 hour to 48 hours, in particular from 2 hours to 30 hours and preferably from 5 hours to 24 hours.

[0099]

[0072] The process according to the invention may include a step of purifying oligomers from the decomposition of the binder by filtering and washing the treated material, preferably first with a polar aprotic solvent, for example as defined in this text, and then with a solvent selected from water, an aqueous solution, a primary C1-C5 alcohol and mixtures thereof, said solvent being preferably introduced into a solution comprising a salt such as NaCl, at a concentration of 1 gL -1at 400 gL -1 .

[0100]

[0073] This step allows the said oligomers to be precipitated in order to isolate them from the reaction medium.

[0101]

[0074] Compared to purification by distillation, which involves heating, this method has the advantage of not exposing the oligomers to heat, to which they are sensitive. Indeed, under the effect of heat, they are likely to re-polymerize.

[0102]

[0075] The process according to the invention may further include steps of recovering the material treated with the amine, washing, preferably with water or with an aqueous solution, and drying, in order to obtain mineral fibers.

[0103]

[0076] Said mineral fibres can then be reused in the manufacture of a material, possibly after carding.

[0104]

[0077] The new material can be, for example, a new insulating material.

[0105]

[0078] The invention also relates to the use of a solution comprising an amine and a polar aprotic solvent to decompose a binder contained in a material in the form of a veil, mat, or felt of mineral fibers. The amine, the polar aprotic solvent, and the binder being as defined above.

[0106]

[0079] The process according to the invention leads to the obtaining of oligomers soluble in the aprotic polar solvent, resulting from the decomposition of the binder in contact with the amine.

[0107]

[0080] Another object of the present invention is therefore an oligomer that can be obtained by a process according to the invention.

[0108]

[0081] Such oligomers comprise the following motifs (B), and optionally (A) [Chem 1]

[0109]

[0110]

[0082] where each R2 and R3 are independently chosen from a hydrogen radical and a C1-C5 alkyl, and

[0111]

[0083] where each of R4, R4' and R4” is chosen from the group consisting of a hydrogen radical, a hydroxy radical, alkyls, cycloalkyls, aryls and heteroaryls, saturated or unsaturated, linear or branched, whose hydrocarbon chain contains from 1 to 20 carbon atoms, possibly substituted by at least one group chosen from hydroxyl, amine and aromatic groups and / or interrupted by at least one oxygen or nitrogen atom.

[0112]

[0084] Preferably, each of R4, R4' and R4” is chosen from a hydroxy radical and a hydrogen radical, and at least one of R4, R4' and R4” is a hydroxy radical. Preferably, at least one of R4' and R4” is a hydroxy radical.

[0113]

[0085] In a preferred embodiment of the invention, each R4 is a hydrogen radical.

[0114]

[0086] These motifs are linked to each other and thus form at least one oligomer obtained by a process according to the invention.

[0115]

[0087] In the structures shown above, a bond represented by a dashed line indicates the possibility of a bond. Thus, each motif (B) composing an oligomer according to the invention is selected from the motifs of formulas (B1) to (B10) below [Chem 2]

[0116]

[0117]

[0088] where each X is chosen from -CH2-, -CH2-O-CH2- and -CH2-N(R5”R6”)-CH2-, preferably X is -CH2-,

[0118]

[0089] each of Ri and R is independently chosen from the group consisting of the substituents -H, -CH2OH and -CH2NH2,

[0090] each of R4, R4' and R4” is as defined above,

[0119]

[0091] Each of R5, RÔ, R5', RÔ', RS” and RÔ” is independently chosen from the group consisting of a hydrogen radical, alkyls, cycloalkyls, aryls and heteroaryls, saturated or unsaturated, linear or branched, whose hydrocarbon chain contains from 1 to 20 carbon atoms, optionally substituted by at least one group chosen from hydroxyl, amine and aromatic groups and / or interrupted by at least one oxygen or nitrogen atom,

[0092] the sum of the iterations of motifs (A) and (B) is from 2 to 500,

[0120]

[0093] Each motif (A) is linked to two motifs chosen from motifs (A) and (B),

[0121]

[0094] Each motif (B1) to (B4) is linked to two or three motifs chosen from motifs (A) and (B), and

[0122]

[0095] Each motif (B5) to (B10) is linked to a motif chosen from among the motifs (A) and (B1) to (B4). In this text, the expressions "each R x" or "each of Rx" are intended to be representative of the fact that an oligomer according to the invention may comprise several iterations of a motif (A) and / or (B) as defined above and that for each of these iterations, the substituents R x , including Ri, Rf, R2, R3, R4, R4', R4”, Rs, Rs', R5”, RÔ, RÔ' and RÔ” are independently defined according to this text.

[0123]

[0096] By definition, since the compounds according to the invention are oligomers, their chains comprise a limited number of motifs (B) and optionally (A). Thus, in an oligomer according to the invention, the sum of the iterations of motifs (A) and (B) is from 2 to 500. In particular, this sum is from 3 to 400 and preferably from 5 to 300.

[0124]

[0097] The motifs (B), in particular (B5) to (B10), are located at the ends of the oligomeric chain. In particular, the motifs (B5) to (B10) are not consecutive to another motif (B5) to (B10) within said chain. In other words, each motif (B5) to (B10) is linked to another motif chosen from among the motifs (A) and (B1) to (B4).

[0125]

[0098] In addition to these ends, the oligomeric chain is therefore made up of motifs (A) (optionally) and (B), in particular (B1) to (B4) and optionally (A), said motifs being randomly linked. These motifs can therefore be linked to any other motif chosen from (A) and (B).

[0126]

[0099] In particular, an oligomer according to the invention comprises at least one motif selected from (B1) to (B4).

[0100] In the present text, the expression "(BX) to (BY)" is meant to designate all motifs (B) of order from X to Y. For example, the expression "(B5) to (B10)" designates all motifs of order from 5 to 10, that is to say: (B5), (B6), (B7), (B8), (B9) and (B10).

[0127]

[0101] Aminolysis of a phenolic resin leads to an oligomer substantially composed of motifs (B). Such an oligomer is a preferred embodiment of the invention.

[0128]

[0102] Aminolysis of a phenolic resin modified with urea leads to an oligomer substantially composed of motifs (A) and (B). Such an oligomer is another preferred embodiment of the invention.

[0129]

[0103] Rs, RÔ, Rs', RÔ', Rs” and RÔ”, are defined according to the amine or mixture of amines used for the decomposition of the binder leading to the oligomer according to the invention. In particular, R5, RÔ, RS', RÔ', RS” and RÔ” are the substituents carried by this or these amine(s).

[0130]

[0104] In a particular embodiment of the invention, each of Rs, RÔ, RS', RÔ', Rs” and RÔ” is independently chosen from the group consisting of a hydrogen radical and saturated alkyls, in particular in Ci-Cs, substituted by at least one hydroxyl group, preferably each Rs, Rs' and Rs” being identical to each other and each RÔ, RÔ' and RÔ” being identical to each other.

[0131]

[0105] In a particular embodiment, an oligomer according to the invention comprises the motifs (B) and optionally (A) as defined above, where each (B) is chosen from the motifs of formulas (B1) to (B10) as defined above and where

[0132] X is chosen from -CH2-, -CH2-O-CH2- and -CH2-N(RS”RÔ”)-CH2-,

[0133] Each Ri and Rf are chosen independently from the group consisting of the substituents -H, -CH2OH and -CH2NH2,

[0134] Each R2 and R3 are independently chosen from a hydrogen radical and a C1-C5 alkyl group,

[0135] at least one of R4, R4' and R4” is a hydroxy radical,

[0136] Each R4 is chosen from the group consisting of a hydrogen radical, a hydroxy radical, alkyls, cycloalkyls, aryls and heteroaryls, saturated or unsaturated, linear or branched, whose hydrocarbon chain contains from 1 to 20 carbon atoms, possibly substituted by at least one group chosen from the hydroxyl, amine and aromatic groups and / or interrupted by at least one oxygen or nitrogen atom, preferably each R4 is a hydrogen radical,

[0137] each R5, RÔ, R5', RÔ', RS” and RÔ” are independently chosen from the group consisting of a hydrogen radical, saturated or unsaturated alkyls, cycloalkyls, aryls and heteroaryls, linear or branched, whose hydrocarbon chain contains from 1 to 20 carbon atoms, possibly substituted by at least one group chosen from hydroxyl, amine and aromatic groups and / or interrupted by at least one oxygen or nitrogen atom, in particular each R5, RÔ, R5', RÔ', RS” and RÔ” are independently chosen from the group consisting of a hydrogen radical and saturated alkyls substituted by at least one hydroxyl group,

[0138] preferably each R5 is identical to each R5' and each RÔ is identical to each RÔ',

[0139] the sum of the iterations of patterns (A) and (B) is between 2 and 500, each pattern (A) is linked to two patterns chosen from patterns (A) and (B), each pattern (B1) to (B4) is linked to two or three patterns chosen from patterns (A) and (B), and

[0140] Each pattern (B5) to (B10) is linked to a pattern chosen from among the patterns (B1) to (B4) and (A).

[0141]

[0106] The present invention also relates to a mixture of oligomers according to the invention. Such a mixture is obtained in particular by implementing a recycling process according to the invention.

[0142] Examples

[0143]

[0107] Tests were carried out on a 1 g sample of a novolac phenolic resin-based binder. The samples were ground in a mortar and then placed in 20 mL of dimethyl sulfoxide (DMSO) solution containing an amine and refluxed at a temperature as indicated in Table 1 below, for 9 h with stirring at 200 rpm. The reaction mixture was then filtered through a Büchner funnel and washed with DMSO and then with water. The residue was dried under vacuum in a chamber at 40 °C for 48 h. The filtrate was then precipitated in brine with stirring at 200 rpm, filtered again through a Büchner funnel, and washed with water. The different experimental conditions are presented in Table 1 below. [Table 1]

[0144] Ex. 1 Comp. 1 Comp. 2 Ex. 2 Ex. 3 Amino-2-Amine Aminopropanol Aniline Pyridine Piperidine propanol Solubility in

[0145] Water at 20°C Soluble 34 Soluble Soluble Soluble (g / L)

[0146] Temperature (°C) 187 185 115 106 160 Rate of

[0147] Depolymerization 74 0 0 30 48 (% wt.)

[0148] Residual rate (%

[0149] 27 - 100 90 26 wt.)

[0150]

[0151] Ex. 4 Ex. 5 Ex. 6 Ex. 7

[0152] 2- 2- Benzyl tert-octyl

[0153] Amine (methylamino) (ethylamino)

[0154] amine amine

[0155] ethanol ethanol Solubility in

[0156] Water at 25°C Soluble Soluble Insoluble Soluble

[0157] (g / L)

[0158] Temperature (°C) 170 185 177 170

[0159] Rate of

[0160] depolymerization 76 - 19 21

[0161] (% wt.)

[0162] Residual rate (%

[0163] 35 35 88 43

[0164] wt.)

[0165]

[0166]

[0108] The depolymerization rate expresses the mass of oligomers obtained relative to the initial mass of binder, at the end of the process described in the preceding paragraph.

[0109] The residual rate expresses the mass of undissolved binder obtained after filtration relative to the initial mass of binder.

[0167]

[0110] The sum of these rates may differ from 100% in cases, for example, of grafting the amine onto the residual binder or if the latter is not perfectly dry and still contains water, amine and / or solvent.

[0168] [11 l]These examples therefore demonstrate that it is possible to obtain oligomers from a phenolic resin using different amines but that amines carrying a hydroxy group are particularly effective for this purpose.

[0169]

[0112] It is also noted that the solubility of the amine in water is advantageous for allowing purification of oligomers.

[0170]

[0113] An amine with a higher boiling point also allows the reaction to be carried out at a higher temperature and therefore to benefit from a better depolymerization rate.

[0171]

[0114] In summary, the examples below demonstrate that an amine particularly suitable for the invention is soluble in water and / or has a high boiling point (approximately above 150 °C) and / or carries a hydroxy group.

[0172]

[0115] Aminopropanol, meeting all these conditions, allows obtaining particularly advantageous depolymerization rates and residual binder rates.

[0173]

[0116] Following the same protocol as described above, different solvents were tested for washing, using aminopropanol as the amine. They are presented in the table below:

[0174] [Table 2] Dimethyl

[0175] Dichloro Trichloro Solvent sulfoxide Acetone

[0176] methane (DMSO)

[0177] Temperature

[0178] 189 56 39 61 boiling point (°C)

[0179] Solubilization of

[0180] +++ + ++ ++ oligomers

[0181] Polarity

[0182] 4.2 2.1 1.3 1.8 (Debye index)

[0183] Protic or

[0184] Aprotic Protic Aprotic Aprotic?

[0185] Dimethyl Acetate

[0186] Solvent Ethanol Acetonitrile Ethyl formamide

[0187] (DMF) Temperature

[0188] 78 81 77 153 boiling point (°C)

[0189] Solubilization of

[0190] + + + +++ oligomers

[0191] Polarity

[0192] 2.4 4.6 5.2 3.8 (Debye index)

[0193] Protic or

[0194] Protic Aprotic Aprotic Aprotic aprotic?

[0195]

[0196]

[0117] Similar to what has been observed for amines, several factors influence the ability of a solvent to solubilize oligomers. This is visually indicated by "+" for poor solubilization, "++" for incomplete solubilization, or "+++" for good solubilization.

[0197]

[0118] The examples tested above demonstrate that the polar and / or aprotic character of a solvent promotes the solubilization of oligomers.

[0198]

[0119] Priority solvents, such as DMSO or DMF, also have a high boiling point. Table 3 below shows the effects of using a solvent with a high boiling point (DMSO) with the amine during aminolysis.

[0199] [Table 3]

[0200] Ex. 8 Comp. 3 Ex. 9 Ex. 10 Ex. 11 Ex. 12 Aminopropanol volume (mL) 20 0 10 5 2.5 0.60 DMSO volume (mL) 0 20 10 15 17.5 19.4 Temperature (°C) 187 189 189 189 189 189 Time (h) 9 72 9 9 9 9

[0201] Depolymerization rate (% wt.) 74 9 68 73 77 61 Residual rate (% wt.) 27 96 - 8 - 31

[0202]

[0203]

[0120] It is observed that the conditions of examples 10 and 11, i.e. the use during the aminolysis of an amine solution in DMSO at a volume rate of amine ranging from 12.5% ​​to 25%, make it possible to improve the rate of depolymerization and / or the residual rate.

[0204]

[0121] Table 4 below shows the effects of temperature during aminolysis.

[0205] [Table 4]

[0206] Ex. 13 Ex. 14 Ex. 15

[0207] Reaction time (h) 9 9 24

[0208] Temperature (°C) 187 100 50

[0209] Depolymerization rate (% wt.) 74 20 12

[0210] Residual rate (% wt.) 27 83 84

[0211]

[0212]

[0122] It is observed that above 100 °C (example 13), depolymerization occurs in a particularly satisfactory quantity.

Claims

Demands 1) A process for recycling a material in the form of a veil, mattress or felt of mineral fibres, in particular in the form of mineral wool, bonded with a binder comprising at least one thermosetting resin, said process comprising a step of bringing said material into contact with at least one amine in solution in a polar aprotic solvent, at a temperature of at least 50 °C, in particular at least 80 °C and preferably at least 100 °C for a period sufficient to decompose said binder. 2) A method according to the preceding claim, characterized in that the material comprises from 60 to 99% by weight of mineral fibers, preferably from 65 to 99% by weight of mineral fibers, for example from 75 to 99% by weight of mineral fibers, relative to the total weight of the material. 3) A method according to any one of the preceding claims, characterized in that the material is in the form of a veil of mineral fibers bonded with a binder comprising a urea-formaldehyde resin or a melamine-formaldehyde resin, preferably a urea-formaldehyde resin, or is in the form of mattress or mineral wool felt containing mineral fibers which represent 80 to 99% by weight of the total weight of the material. 4) A process according to any one of the preceding claims, characterized in that the binder comprises a phenolic resin optionally modified with an amine or with urea, in particular an amine-modified phenolic resin consisting essentially of phenol-formaldehyde condensates and phenol-formaldehyde-amine condensates or consisting essentially of phenol-formaldehyde condensates and phenol-formaldehyde-urea condensates. 5) A method according to any one of the preceding claims, characterized in that the binder comprises a urea-formaldehyde resin or a melamine-formaldehyde resin, preferably a urea-formaldehyde resin. 6) A process according to any one of the preceding claims, characterized in that the amine is soluble in water at 25 °C, in particular the solubility of the amine in water at 25 °C is at least 60 g / L and preferably at least 100 g / L. 7) A process according to any one of the preceding claims, characterized in that the amine has a boiling point of at least 50 °C, in particular of at least 80 °C and preferably of at least 100 °C. 8) A process according to any one of the preceding claims, characterized in that the amine is selected from primary or secondary hydrocarbon mono- or polyamines, saturated or unsaturated, linear, branched or cyclic, optionally aromatic, whose hydrocarbon chain contains from 1 to 20 carbon atoms and is optionally substituted by at least one group selected from hydroxyl and aromatic groups and / or is interrupted by at least one oxygen atom; and mixtures thereof, in particular the amine is selected from saturated primary or secondary amines substituted by at least one group selected from hydroxyl and aromatic groups; and mixtures thereof, preferably the amine is selected from saturated primary or secondary amines substituted by at least one hydroxyl group. 9) A process according to any one of the preceding claims, characterized in that the amine is selected from aminopropanol, amino-2-propanol, 2-(methylamino)ethanol, benzylamine, and mixtures thereof; in particular, the amine is selected from aminopropanol, amino-2-propanol, 2-(methylamino)ethanol, and mixtures thereof; preferably, the amine is selected from aminopropanol, 2-(methylamino)ethanol, and mixtures thereof. 10) A process according to any one of the preceding claims, characterized in that the contact between the material and the amine is carried out at a temperature of 50 °C to 300 °C, in particular from 75 °C to 250 °C, and preferably from 100 °C to 200 °C. 11) A process according to any one of the preceding claims, characterized in that the aprotic polar solvent is selected from dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), hexamethylphosphoramide (HMPA), A,A'-dimethylpropylene urea (DMPU), and mixtures thereof; in particular the solvent is selected from DMSO, DMF, and mixtures thereof; preferably the solvent is DMSO. 12) A process according to any one of the preceding claims, characterized in that the amine represents from 2% to 30% of the volume, in particular from 5% to 25% of the volume and preferably from 7% to 15% of the volume, relative to the total volume of solution. 13) A process according to any one of the preceding claims, characterized in that it comprises, prior to or concurrently with the step of bringing the material into contact with the amine, a step of comminution of the material. 14) A process according to any one of the preceding claims, characterized in that it comprises a step of purifying oligomers from the decomposition of the binder by filtration and washing of the treated material, preferably first with a polar aprotic solvent, for example as defined in claim 9, and then with a solvent selected from water, an aqueous solution, a primary C1-C5 alcohol and mixtures thereof, said solvent being introduced preferably in a solution comprising a salt such as NaCl, at a concentration of 1 gL -1 at 400 gL -1 . 15) A process according to any one of the preceding claims, characterized in that it further comprises steps of recovering the amine-treated material, washing, and preferably with water or an aqueous solution, and drying, in order to obtain mineral fibers. 16) A process according to the preceding claim, characterized in that the recovered mineral fibers are reused in the manufacture of a material, possibly after carding. 17) Use of a solution comprising an amine and an aprotic polar solvent as defined in any one of the preceding claims, to decompose a binder as defined in any one of the preceding claims, contained in a material in the form of a veil, a mat or a mineral fibre felt. 18) Oligomer capable of being obtained by a process according to any one of claims 1 to 16 comprising motives (B) and optionally (A) where each (B) is chosen from the formula patterns (B1) to (B10) X is chosen from -CH2-, -CH2-O-CH2- and -CH2-N(R5”R6”)-CH2-, preferably X is -CH2-, Each R1 and R1' is independently chosen from the group consisting of the substituents -H, -CH2OH and –CH2NH2, Each R2 and R3 is independently chosen from a hydrogen radical and a C1-C5 alkyl group, at least one of R4, R4' and R4” is a hydroxy radical, each R4, R4' and R4” is chosen from the group consisting of a hydrogen radical, a hydroxy radical, alkyls, cycloalkyls, aryls and heteroaryls, saturated or unsaturated, linear or branched, whose hydrocarbon chain contains from 1 to 20 carbon atoms, possibly substituted by at least one group chosen from the hydroxyl, amine and aromatic groups and / or interrupted by at least one oxygen or nitrogen atom, preferably at least one of R4, R4' and R4” is a hydroxy radical and the others is (are) a hydrogen radical, each R5, RÔ, R5', RÔ', RS” and RÔ” is independently chosen from the group consisting of a hydrogen radical, alkyls, cycloalkyls, aryls and heteroaryls, saturated or unsaturated, linear or branched, whose hydrocarbon chain contains from 1 to 20 carbon atoms, possibly substituted by at least one group chosen from hydroxyl, amine and aromatic groups and / or interrupted by at least one oxygen or nitrogen atom, in particular each R5, RÔ, R5', RÔ', RS” and RÔ” is independently chosen from the group consisting of a hydrogen radical and saturated alkyls, in particular in Ci-Cs, substituted by at least one hydroxyl group, preferably each R5, R5' and R5” being identical to each other and each RÔ, RÔ' and RÔ” being identical to each other, the sum of the iterations of patterns (A) and (B) is between 2 and 500, each pattern (A) is linked to two patterns chosen from patterns (A) and (B), each pattern (B1) to (B4) is linked to two or three patterns chosen from patterns (A) and (B), and Each pattern (B5) to (B10) is linked to a pattern chosen from among the patterns (B1) to (B4) and (A).

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