Polystyrene-based composite material and method of obtaining same

Abstract

The invention relates to a mush composition loaded with filler, comprising a polystyrene mush as well as at least one filler, and to a method for preparing same. Also provided are a composite material obtained from the filler-loaded mush composition, and to a method for preparing same. A container containing the filler-loaded mush composition is also described. The invention also relates to a part made of a composite material and to a method for preparing same. Lastly, the invention relates to a method for recycling a part made of composite material.

Description

[0001] Description

[0002] Title of the invention: Polystyrene-based composite material and its method of production

[0003] Background of the invention

[0004] The invention relates to the valorization of polystyrene waste. More specifically, the invention concerns the preparation of composite materials based on polystyrene and fillers, and their use in the production of composite parts exhibiting good mechanical strength. The invention also relates to the recycling of this composite material.

[0005] Object and summary of the invention

[0006] In general, it is desirable to recover value from various types of waste, whether industrial or not. Ideally, this recovery should be economical, energy-efficient, and easy to implement.

[0007] The use of expanded polystyrene is widespread, generating large quantities of expanded polystyrene waste that is difficult to reuse, particularly for food applications. To date, two different techniques have been proposed for treating expanded polystyrene waste: destruction or recycling.

[0008] The destruction of expanded polystyrene is typically carried out by incineration. Although this allows for the recovery of thermal energy, this solution is neither economical nor environmentally friendly. Recycling is a preferred alternative.

[0009] Expanded polystyrene (EPS) can be recycled either mechanically or chemically. Mechanical recycling involves crushing the EPS, then compacting it, and finally generating polystyrene granules. A drawback of mechanical recycling is that it requires prior cleaning of the EPS to be recycled. Furthermore, mechanical recycling requires high pressure and temperature to soften the EPS, and is therefore energy-intensive. It should also be noted that EPS residues can easily be dispersed during mechanical recycling. Moreover, mechanical recycling does not allow for the subsequent use of the recovered EPS for food contact, but only for non-food applications such as insulation or appliance packaging. Chemical recycling generally involves depolymerizing the EPS to recover styrene.The most common method for the chemical recycling of expanded polystyrene is thermal depolymerization, or thermolysis, using conventional heat or microwaves. This method involves thermally cracking the polymer and breaking its chains to obtain monomers (benzene, toluene, styrene). The yield of aromatic compounds from polystyrene is high. The resulting styrene monomer can then be repolymerized to obtain polystyrene. This method makes it possible to consider reusing polystyrene for food contact applications. However, thermal depolymerization is energy-intensive and very expensive.

[0010] An alternative method was described in French patent FR 2 766832, which concerns a process for transforming expanded polymers, particularly expanded polystyrene, into a flexible, pasty magma resulting from the collapse of the expanded polystyrene's internal structure, without any chemical modification of the latter. The described process involves treating the expanded polystyrene with a transformation composition comprising a solvent, a non-greasy lubricant, and an alcohol. Various uses for the resulting magma are envisaged, such as the manufacture of piping components, basins, boxes, protective housings, insulation, gaskets, or adhesives, although no explanation is provided for their implementation. The preparation of adhesive from such a magma was considered in French patent application FR2407141.

[0011] In this context, the Applicant became interested in the valorization of waste, and in particular expanded polystyrene waste, for the production of composite parts. More specifically, the invention relates to a charged magma composition comprising, preferably consisting essentially of, and even better consisting of:

[0012] - a polystyrene magma containing at least 70% by weight of polystyrene relative to the weight of the polystyrene magma, said polystyrene being in an amorphous, unexpanded state, and

[0013] - 25% to 75% by weight of one or more fillers, relative to the weight of the polystyrene magma and filler(s).

[0014] The charged magma composition has the advantage of being able to be stored for later use in the manufacture of a composite material according to the invention, or of a part made of composite material according to the invention.

[0015] The charged magma composition according to the invention exhibits one or more of the following characteristics, or a combination thereof:

[0016] - the filler(s) are chosen from: o plant-based fillers, preferably chosen from wood-based fillers, flax-based fillers, carbon fibers, and mixtures thereof,

[0017] o mineral fillers, preferably chosen from calcium carbonate, silica, sand, glass wool, rock wool, and mixtures thereof,

[0018] o - metallic fillers, preferably selected from steel, iron, copper, zinc, aluminum, their alloys, and mixtures thereof; o Ceramic fillers, preferably selected from oxides, nitrides, carbides, borides, and mixtures thereof, and in particular iron oxide, lead oxide, titanium oxide, magnesium oxide, zirconium oxide, tungsten nitride, titanium nitride, silicon nitride, silicon carbide, tungsten carbide, iron boride, titanium boride, zirconium boride, and mixtures thereof; and

[0019] or their mixtures;

[0020] - the charge(s) are in the form of powder, chips, fibers, or fragments whose largest dimension is less than or equal to 1 cm;

[0021] - the polystyrene magma comprises a transformation composition, preferably with a content of at least 15% by weight, preferably from 15% to 50% by weight, preferably from 15% to 40% by weight, preferably from 15% to 25% by weight, and even better from 17% to 20% by weight, relative to the total weight of the polystyrene magma;

[0022] The transformation composition includes, in relation to the volume of the transformation composition:

[0023] o at least one solvent, preferably a solvent, in a content preferably ranging from 92% to 98% by volume, said solvent preferably being acetone,

[0024] at least one lubricant, preferably a lubricant, preferably with a content ranging from 1% to 2% by volume, said lubricant preferably being glycerin, and

[0025] o at least one alcohol, preferably in a content ranging from 0.5% to 6% by volume, preferably 1% to 2% by volume, said at least one alcohol being preferably chosen from aliphatic or cycloaliphatic alcohols, linear or branched, comprising 1 to 15 carbon atoms;

[0026] - the composition of charged magma further includes 0.25 kg to 0.4 kg of at least one chlorinated solvent per kg of magma;

[0027] - the chlorinated solvent is chosen from trichloroethylene, tetrachloroethylene, and mixtures thereof; and

[0028] - the composition of charged magma further includes at least one additive, preferably chosen from colorants, flame retardants, UV inhibitors, plasticizers, and mixtures thereof.

[0029] The invention further relates to a method for preparing a charged magma composition comprising, preferably, the following steps:

[0030] a) to have a polystyrene magma containing at least 70% by weight of polystyrene, relative to the weight of the magma, said polystyrene being in an amorphous, non-expanded state,

[0031] b) have at least one charge,

[0032] c) mix the polystyrene magma and 25% to 75% by weight of at least one filler relative to the weight of the polystyrene magma and filler(s), and possibly 0.25 kg to 0.4 kg of at least one chlorinated solvent per kg of magma, in order to obtain a charged magma composition.

[0033] The process for preparing the filled magma composition has the advantage of being simple and quick to implement. The process is carried out under mild conditions (ambient temperature or low heating, atmospheric pressure, no need for an inert atmosphere). This process also has the advantage of not requiring complex and / or expensive equipment. Furthermore, it utilizes materials derived from waste, whether industrial or not: the polystyrene magma is made from expanded polystyrene waste, and the fillers used can also be waste-derived.

[0034] The invention further relates to a container holding the charged magma composition according to the invention, or obtained according to the process of the invention. Said container is preferably hermetically sealed in order to increase the storage time of the charged magma composition.

[0035] The invention also relates to a composite material comprising, preferably consisting essentially of, and more preferably consisting of:

[0036] - polystyrene, and - one or more fillers, in a mass ratio of filler(s) / polystyrene ranging from 0.3 to 4.

[0037] The Applicant has discovered, surprisingly, that mixing various fillers with polystyrene produces a composite material with interesting physicochemical properties, particularly good mechanical strength and resistance to moisture and water. Furthermore, this composite material has the advantage of being easily molded. In addition, this composite material allows for the recycling and recovery of polystyrene waste, especially expanded polystyrene, but also potentially industrial waste, wood, or metal waste, for example. Finally, the composite material according to the invention has the advantage of being easily recyclable.

[0038] The composite material according to the invention may have one or more of the following characteristics:

[0039] - the charge(s) are chosen from:

[0040] o plant-based fillers, preferably chosen from wood-based fillers, flax-based fillers, carbon fibers, and mixtures thereof,

[0041] o - mineral fillers, preferably chosen from calcium carbonate, silica, sand, glass wool, rock wool, clay, kaolin, quartz, feldspar, and mixtures thereof,

[0042] o - metallic fillers, preferably selected from steel, iron, copper, zinc, aluminum, their alloys, and mixtures thereof,

[0043] o - ceramic fillers, preferably selected from oxides, nitrides, carbides, borides, and mixtures thereof, and in particular iron oxide, lead oxide, titanium oxide, magnesium oxide, zirconium oxide, tungsten nitride, titanium nitride, silicon nitride, silicon carbide, tungsten carbide, iron boride, titanium boride, zirconium boride, and mixtures thereof, and

[0044] o - their mixtures; and

[0045] - the composite material further comprises at least one chlorinated solvent in a mass ratio of chlorinated solvent(s) / polystyrene ranging from 0.25 to 0.6, said at least one chlorinated solvent being chosen from trichloroethylene, tetrachloroethylene and their mixture.

[0046] The invention also relates to a method for preparing a composite material according to the invention. This preparation method preferably comprises the following steps: 1) having a polystyrene magma containing at least 70% by weight of polystyrene, relative to the weight of the magma, said polystyrene being in an amorphous, unexpanded state,

[0047] 2) to have at least one charge,

[0048] 3) Mix the polystyrene magma with 25% to 75% by weight of at least one filler, relative to the weight of the polystyrene magma and filler(s), and optionally 0.25 kg to 0.4 kg of at least one chlorinated solvent per kg of magma, in order to obtain a charged magma composition, and

[0049] 4) dry the charged magma composition.

[0050] The composite material preparation process according to the invention has the advantage of being simple and quick to implement. The process is carried out under mild conditions (ambient temperature or low heating, atmospheric pressure, no need for an inert atmosphere). This process also has the advantage of not requiring complex and / or expensive equipment. Furthermore, this process has the advantage of using materials derived from waste, whether industrial or not: the polystyrene magma is derived from expanded polystyrene waste, and the fillers used can also come from waste.

[0051] The manufacturing process of the composite material according to the invention may include a step 2') subsequent to step 2) and prior to step 3), consisting of adding to the at least one filler 50 mL to 1000 mL of a transformation composition per kg of filler(s), preferably 100 mL to 500 mL, and better still 150 mL to 250 mL.

[0052] The invention further relates to a part made of a composite material according to the invention, or of a composite material obtained according to the process according to the invention. This part is advantageously prepared according to a process which preferably comprises the following steps:

[0053] (i) possess a charged magma composition according to the invention, or obtained according to the process of the invention,

[0054] ii) place the loaded magma composition into a mold having the desired shape of the part,

[0055] iii) dry the charged magma composition, and

[0056] iv) demold the resulting composite material part.

[0057] This process may include a step (v) subsequent to step (iv), consisting of machining the resulting composite part. Finally, the invention relates to a process for recycling at least one composite part according to the invention, or obtained according to the process according to the invention, comprising, in particular, the following steps:

[0058] I) to have at least one part made of composite material according to the invention, or obtained in accordance with the process according to the invention,

[0059] II) to have a transformation composition comprising, in relation to the volume of the transformation composition:

[0060] - at least one solvent, preferably a solvent, in a concentration preferably ranging from 92% to 98% by volume, said solvent preferably being acetone, - at least one lubricant, preferably a lubricant, preferably in a concentration ranging from 1% to 2% by volume, said lubricant preferably being glycerin, and

[0061] - at least one alcohol, preferably in a content ranging from 0.5% to 6% by volume, preferably 1% to 2% by volume, said at least one alcohol being preferably chosen from aliphatic or cycloaliphatic alcohols, linear or branched, comprising 1 to 15 carbon atoms,

[0062] III) bring at least one part made of composite material into contact with the transformation composition, and

[0063] IV) separate the polystyrene magma on one side and at least one charge on the other.

[0064] The recycling process according to the invention thus makes it possible to reuse all the materials to produce a new composite material. No waste is generated. Furthermore, the recycling process has the advantage of being quick and easy to implement, requiring only mild conditions and readily available equipment. The recycling process according to the invention is inexpensive and energy-efficient.

[0065] During the recycling process according to the invention, step IV) of separation can be carried out by removing the supernatant by aspiration or by filtration.

[0066] Brief description of the drawings

[0067] Other features and advantages of the present invention will become apparent from the description below, with reference to the accompanying drawings which illustrate an example of an embodiment without being limiting in any way. In the figures: - Figure 1 is a photograph of the CMC5-charged magma composition according to Example 1,

[0068] - Figure 2 is a photograph of the part made of composite material P7 according to example 1, - Figure 3 is a photograph of the part made of composite material P8 according to example 1, - Figure 4 is a photograph of the part made of composite material P9 according to example 1, - Figure 5 is a photograph of two parts made of composite material P9 of different shapes, and of a part made of composite material P10, and

[0069] - Figure 6 is a photo of a BIC® pen used for the preparation of magma M3, of the charged magma composition CMC12, and of the composite material part P 12.

[0070] Detailed description of the invention

[0071] The invention relates to a charged magma composition comprising, preferably consisting essentially of, and even better consisting of:

[0072] - a polystyrene magma as described below, or obtained in accordance with the process described below,

[0073] - from 25 to 75% by weight, preferably from 28% to 72% by weight, preferably from 30% to 62% by weight, and even better from 40% to 53% by weight, relative to the total weight of magma and charge(s), of one or more charges, said charges being as described above,

[0074] - possibly at least one chlorinated solvent, as described below, in a content preferably ranging from 0.25 kg to 0.40 kg, preferably from 0.28 kg to 0.36 kg, of chlorinated solvent per kg of polystyrene magma,

[0075] - possibly at least one additive, as described below, preferably in a content of less than 10% by weight relative to the weight of the loaded magma composition.

[0076] According to a first embodiment, the composition of the charged magma comprises, preferably consists essentially of, and even better consists of:

[0077] - a polystyrene magma as described below, or obtained in accordance with the process described below,

[0078] - from 25% to 75% by weight, preferably from 28% to 72% by weight, preferably from 30% to less than 60% by weight, and better still from 40% to 53% by weight, relative to the total weight of magma and charge(s), of one or more charges, said charges being as described below, and - possibly at least one additive, as described above, preferably in a content of less than 10% by weight relative to the weight of the charged magma composition.

[0079] According to a second embodiment, the composition of the charged magma comprises, preferably consists essentially of, and better still consists of:

[0080] - a polystyrene magma as described below, or obtained in accordance with the process described below,

[0081] - from 25% to 75% by weight, preferably from 28% to 72% by weight, preferably from 60% to 72% by weight, and even better from 63% to 72% by weight, relative to the total weight of magma and charge(s), of one or more charges, said charges being as described below,

[0082] - at least one chlorinated solvent, as described below, in a content preferably ranging from 0.25 kg to 0.40 kg, preferably from 0.28 kg to 0.36 kg, of chlorinated solvent per kg of polystyrene magma,

[0083] - possibly at least one additive, as described below, preferably in a content of less than 10% by weight relative to the weight of the loaded magma composition.

[0084] In the context of this invention, "magma" refers to a thick, pasty, and flexible mass with a consistency similar to that of a resin. Polystyrene magma is obtained by treating polystyrene (expanded, semi-expanded, extruded, crystalline, etc.) with a transformation composition, as detailed below, resulting in a collapse of the internal structure of the expanded polystyrene or a reorganization of the non-expanded polystyrene, without any chemical modification of the polymer. Thus, polystyrene magma (or simply magma in the following description) comprises polystyrene in a non-expanded and amorphous form.

[0085] The polystyrene magma comprises predominantly polystyrene and a minor amount of the transformation composition. The polystyrene is in an amorphous, unexpanded state within the magma. More precisely, the magma comprises at least 70% by weight of polystyrene relative to the total weight of the magma, preferably 75% to 85% by weight, and even more preferably 80% to 83% by weight. Preferably, the magma comprises less than 30% by weight, preferably 15% to 25% by weight, and even more preferably 17% to 20% by weight of the transformation composition, relative to the total weight of the magma. According to a particular embodiment of the invention, the magma used comprises 17% by weight of the transformation composition relative to the total weight of the magma.Preferably, the magma comprises, preferably consists of, at least 70% by weight, preferably 75% to 85% by weight, and even better 80% to 83% by weight of polystyrene, and less than 30% by weight, preferably 15% to 25% by weight, and even better 17% to 20% by weight of transformation composition, the percentages being expressed as a percentage of the total weight of the magma. It is possible for the magma to contain more than 30% by weight of transformation composition, but this is not preferred as it is less economical (due to a larger quantity of transformation composition used) and the magma volumes are larger (and therefore less easily handled).

[0086] The charged magma composition advantageously comprises, relative to the weight of the charged magma composition, at least 15% by weight of transformation composition, preferably from 15% to 50% by weight, preferably from 15% to 40% by weight.

[0087] In the context of the invention, the transformation composition comprises at least one solvent, at least one lubricant and at least one alcohol.

[0088] Various solvents or solvent mixtures can be used in the transformation composition, such as acetone. In an advantageous embodiment, the transformation composition comprises acetone, alone or in a mixture with one or more other solvents. In a particularly preferred embodiment of the invention, the transformation composition comprises a single solvent, which is preferably acetone.

[0089] The transformation composition comprises 92% to 98% by volume of solvent(s), preferably 94% to 98% by volume, preferably 96% to 98% by volume, and even more preferably 97% to 98% by volume, relative to the volume of the transformation composition. According to a particular embodiment of the invention, the transformation composition comprises 97% by volume of solvent(s).

[0090] According to an advantageous embodiment of the invention, the transformation composition comprises at least 50% by volume of acetone, preferably at least 70% by volume, preferably at least 90% by volume, preferably from 92% to 98.5% by volume, preferably from 94% to 98% by volume, preferably from 96% to 98% by volume, and even more preferably from 97% to 98% by volume, relative to the volume of the transformation composition. According to a particularly advantageous embodiment, the transformation composition comprises 97% by volume of acetone, relative to the volume of the transformation composition.

[0091] At least one lubricant in the processing composition is preferably a non-greasy lubricant, such as Teflon (or polytetrafluoroethylene or PTFE) or glycerin, for example. Advantageously, the processing composition comprises glycerin, alone or in combination with one or more other lubricants. According to a particularly preferred embodiment of the invention, the processing composition comprises a single non-greasy lubricant, which is preferably glycerin.

[0092] Advantageously, the transformation composition comprises 1 to 2% by volume of lubricant(s), preferably 1.5% to 2% by volume, relative to the volume of the transformation composition.

[0093] According to an advantageous embodiment of the invention, the transformation composition comprises 1 to 2% by volume of glycerin, preferably 1.5% to 2% by volume, relative to the volume of the transformation composition. According to a particularly advantageous embodiment, the transformation composition comprises 1.5% by volume of glycerin, relative to the volume of the transformation composition.

[0094] Various alcohols can be used in the transformation composition.

[0095] Advantageously, at least one alcohol in the transformation composition is chosen from among linear or branched aliphatic or cycloaliphatic alcohols comprising 1 to 15 carbon atoms, and preferably from among linear or branched aliphatic alcohols comprising 1 to 10 carbon atoms. Preferably, at least one alcohol is a saturated linear or branched aliphatic or cycloaliphatic alcohol comprising 1 to 15 carbon atoms, and preferably from among linear or branched aliphatic alcohols comprising 1 to 10 carbon atoms. Examples of alcohols that may be used include, in particular, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secbutanol, pentanol, isopentanol, secpentanol, hexanol, cyclohexanol, and mixtures thereof. According to an advantageous embodiment of the invention, at least one solvent is chosen from ethanol, isopropanol and their mixture.According to one particular embodiment of the invention, the transformation composition comprises a single alcohol, namely ethanol. According to another particular embodiment of the invention, the transformation composition comprises a single alcohol, namely isopropanol.

[0096] Advantageously, the transformation composition comprises from 0.5% to 6% by volume of alcohol(s), preferably from 0.5% to 4% by volume, and even more preferably from 1% to 2% by volume, relative to the total volume of the transformation composition. In a particular embodiment, the transformation composition comprises 1.5% by volume of alcohol(s), relative to the volume of the transformation composition. In an advantageous embodiment of the invention, the transformation composition comprises from 0.5% to 6% by volume of ethanol, isopropanol, or a mixture thereof, preferably from 0.5% to 4% by volume, and even more preferably from 1% to 2% by volume, relative to the volume of the transformation composition. In a particular embodiment, the transformation composition comprises 1.5% by volume of ethanol, isopropanol, or a mixture thereof, relative to the volume of the transformation composition.

[0097] According to a particular embodiment of the invention, the transformation composition comprises a single solvent, preferably acetone, a single lubricant, preferably non-greasy, which is preferably glycerin, and at least one alcohol, preferably ethanol or isopropanol, or a mixture thereof.

[0098] According to a particular embodiment of the invention, the transformation composition comprises a single solvent, preferably acetone, a single lubricant, preferably glycerin and a single alcohol, preferably ethanol.

[0099] According to a particular embodiment of the invention, the transformation composition comprises a single solvent, preferably acetone, a single lubricant, preferably glycerin and a single alcohol, preferably isopropanol.

[0100] In the context of the invention, the polystyrene magma can be prepared according to the following successive steps:

[0101] A) to have polystyrene part(s) to treat,

[0102] B) possibly remove impurities from the polystyrene piece(s) and / or possibly crush or grind the polystyrene piece(s) to obtain polystyrene fragments whose largest dimension is less than 30 cm, preferably less than 20 cm, and even better less than 10 cm,

[0103] C) bring the processing composition into contact with the polystyrene piece(s) and / or fragment(s) to be treated,

[0104] D) possibly filter the resulting magma,

[0105] E) possibly eliminate, partially or totally, the transformation composition of the magma obtained, and

[0106] F) possibly add transformation composition.

[0107] In the context of the invention, the magma is obtained from any type of polystyrene, and in particular from expanded and / or semi-expanded and / or extruded and / or crystalline polystyrene. For the sake of simplicity, the entire description refers to expanded polystyrene as it is particularly preferred (because it allows for the recovery of many waste materials), but it is understood that everything described in relation to expanded polystyrene could apply equally to semi-expanded, extruded, crystalline polystyrene or a mixture thereof.

[0108] Expanded polystyrene can come from various sources, such as insulating panels, appliance packaging, or food packaging, for example. It is understood that, within the scope of the invention, the origin of the polystyrene is not limiting, and one or more different sources of polystyrene can be used to manufacture the polystyrene magma. Advantageously, it is not necessary to wash the polystyrene prior to its use: indeed, it is not necessary for the polystyrene to be free of impurities for the manufacture of the polystyrene magma that will be used in the composite material according to the invention. It is nevertheless possible to remove impurities, either when the polystyrene is still in its expanded form, or in step D when the polystyrene is in its amorphous form, or both.

[0109] Advantageously, in step B) of the polystyrene magma preparation process, the polystyrene pieces are crushed to obtain polystyrene fragments whose largest dimension is less than 30 cm, preferably less than 20 cm, and even better, less than 10 cm. It should be noted that the polystyrene fragments are not in granular or pellet form, and that their largest dimension is advantageously greater than 3 cm. It is understood that not all the fragments are necessarily the same size, and that a typical size distribution is obtained.Although not mandatory, this step facilitates the collapse or dispersion of the polystyrene in step C) (i.e. the transformation of the polystyrene in its expanded form to an amorphous non-expanded form, or its reorganization in the case of the use of non-expanded polystyrene), and in particular allows to limit the amount of transformation composition required while maintaining a good rate of collapse.

[0110] In step C) of the polystyrene magma preparation process, the polystyrene is brought into contact with the processing composition in various ways, such as by immersing the polystyrene pieces and / or fragments in the processing composition, or by spraying the processing composition onto the polystyrene pieces and / or fragments. Generally, spraying the processing composition is preferred because the collapse or reorganization of the polystyrene then requires smaller quantities of processing composition, thus reducing costs and potentially eliminating the need for a subsequent step of partially removing the processing composition from the resulting magma. Furthermore, the treatment is faster by spraying than by immersion. Immersion in the processing composition may be preferred when the quantities of expanded polystyrene to be processed are small.

[0111] When spraying the processing composition onto the polystyrene parts and / or fragments, the quantity of processing composition sprayed is determined according to the quantity of polystyrene to be treated. Advantageously, 0.6 kg to 0.9 kg of processing composition per kg of polystyrene to be treated is used, and preferably 0.7 kg to 0.8 kg of processing composition per kg of polystyrene to be treated. In one particular embodiment, 0.75 kg of processing composition per kg of polystyrene is applied. The mass of the resulting magma then corresponds to the sum of the mass of polystyrene treated and the mass of the processing composition sprayed.

[0112] When immersing the polystyrene to be treated (i.e., the polystyrene pieces and / or fragments to be treated), a sufficient quantity is used to ensure that all of the polystyrene is completely submerged in the processing solution. The exact quantities depend on the container and the amount of polystyrene to be treated and can be easily determined by a person skilled in the art. Again, the mass of the resulting solution corresponds to the sum of the mass of the polystyrene to be treated and the mass of the processing solution in which the polystyrene was immersed.

[0113] As detailed above, regardless of the method used to bring the transformation composition into contact with the expanded polystyrene, the latter transitions from an expanded state to an amorphous, unexpanded state. This can be observed through a significant reduction in volume and the formation of a flexible, non-sticky paste.

[0114] In step D) of the polystyrene magma preparation process, the magma can be filtered to remove certain impurities. This optional step can be carried out using a hopper or a filter, for example, the diameter or pore size of which can be adjusted by a person skilled in the art. It is also possible to apply pressure or vacuum at this stage, using techniques known to those skilled in the art, which will not be detailed here.

[0115] Advantageously, the magma is obtained at ambient temperature and atmospheric pressure.

[0116] In step E) of the magma preparation process, it is possible to partially or completely remove the transformation composition. It is advantageous for a minimum amount of the transformation composition to remain in the magma for the subsequent manufacturing of the composite material, so that it does not dry out. Indeed, by completely removing the transformation composition from the magma, it becomes solid and is no longer easily handled.

[0117] According to a first preferred embodiment, the transformation composition is not eliminated during step E). Indeed, according to this embodiment, the quantity of transformation composition applied in step C) is sufficient for the transformation of the expanded polystyrene into magma, and is not greater than the quantity of transformation composition that may be present in the magma for the manufacture of the composite material, as detailed in this description.

[0118] According to a second preferred embodiment, the transformation composition is partially eliminated during step E). Thus, it is possible to reduce the content of the transformation composition in the magma, to subsequently allow the manufacture of the composite material according to the invention.

[0119] Although not preferred, it is nevertheless possible to completely remove the transformation composition from the magma. Once the transformation composition is entirely eliminated, the magma is transformed into a solid and is then composed essentially, or even exclusively, of polystyrene. This solid can then be brought back into contact with the transformation composition to obtain magma, thus regaining the characteristic pasty and flexible form of magma. To facilitate the transformation of the solid into magma, it is advantageous to have the solid in the form of fragments or granules: for this, the solid can be broken into pieces and / or crushed.

[0120] The partial or total removal of the processing composition can be achieved by various techniques, such as evaporation or dewatering. Evaporation can be carried out by heating and / or applying reduced pressure, using techniques known to those skilled in the art. Dewatering can be carried out using any technique known to those skilled in the art, such as centrifugation or compression. Preferably, dewatering is achieved by compression, in particular by compression of the magma, for example, using a conical screw press fitted into a complementary sleeve through which only the processing composition passes. Preferably, the partial removal of the processing composition is achieved by dewatering.

[0121] According to an advantageous embodiment, the transformation composition recovered during the elimination of the transformation composition from the magma is reused in the process of transforming polystyrene into magma, in step C). The process for preparing the polystyrene magma and the device for manufacturing it can be as described in patent FR 2 766 832 and / or in patent application FR 2404962.

[0122] In addition to the polystyrene magma, the filled magma composition includes one or more fillers. These fillers may be in various forms: powder, in particular powder of particles whose largest dimension is less than or equal to 100 microns; chips, in particular chips whose largest dimension is less than 1 cm; fibers, in particular fibers whose largest dimension is less than 1 cm; pellets or granules, in particular those whose largest dimension is less than 1 cm; and / or elements or pieces or fragments whose largest dimension is less than 1 cm.

[0123] In cases where the magma composition contains multiple fillers, these fillers may be of different types, shapes, and / or sizes. The selection of fillers (type, shape, size) and their respective concentrations is determined by a person skilled in the art, based on the desired properties of the magma composition and / or the composite material obtained from it.

[0124] In the context of the invention, the filler(s) can be selected from plant-based fillers, mineral fillers, metallic fillers, ceramic fillers, and / or mixtures thereof. According to a particular embodiment, these fillers can be obtained by grinding waste.

[0125] Examples of plant-based fillers include wood-based fillers, flax-based fillers, and carbon fibers and their mixtures. Wood-based fillers can take the form of sawdust and / or wood chips, and can be made from any type of wood species (e.g., oak, pine, beech, fir, Douglas fir, maple, birch, exotic woods, or bamboo). Sawdust and wood chips are particularly preferred fillers and can be produced from the recovery of waste from the wood industry, especially from machining residues in carpentry, forestry operations, joinery, and the production of wooden toys, for example.

[0126] Examples of mineral fillers include calcium carbonate, silica, sand, glass wool, rock wool, clay, kaolin, quartz, feldspar, and mixtures thereof. Examples of metallic fillers include steel, iron, copper, zinc, aluminum, their alloys, and mixtures thereof. Metallic fillers may originate from scrap metal.

[0127] Examples of ceramic fillers include oxides, nitrides, carbides, borides, and mixtures thereof, and in particular iron oxide, lead oxide, titanium oxide, magnesium oxide, zirconium oxide, tungsten nitride, titanium nitride, silicon nitride, silicon carbide, tungsten carbide, iron boride, titanium boride, zirconium boride, and mixtures thereof.

[0128] In one particular embodiment, the magma composition also includes a chlorinated solvent selected from trichloroethylene, tetrachloroethylene (also known as perch-loroethylene), and mixtures thereof. Tetrachloroethylene is preferably used due to its lower toxicity. In this embodiment, the mass ratio of chlorinated solvent(s) to polystyrene in the magma composition ranges from 0.25 to 0.6, and preferably from 0.28 to 0.5. In another embodiment, the mass ratio of chlorinated solvent(s) to magma in the magma composition ranges from 0.25 to 0.4, and preferably from 0.28 to 0.36. This embodiment is particularly advantageous when the mass ratio of filler(s) to polystyrene in the composition of the filled magma is greater than 1.5, that is to say when the content of filler(s) is at least 60% by weight relative to the total weight of filler(s) and magma.

[0129] According to one embodiment, the filled magma composition also includes one or more additives. Examples of additives include colorants, flame retardants, UV inhibitors, plasticizers, etc. According to this embodiment, the filled magma composition according to the invention comprises one or more additives in a total additive content of less than or equal to 10% by weight, and preferably in a content of less than or equal to 5% by weight, relative to the total weight of the filled magma composition.

[0130] The charged magma composition has the advantage of being able to be stored in a container, preferably a sealed one to prevent drying. The applicant has determined that it is possible to store the charged magma composition in a hermetically sealed container for at least two months under ambient air, at room temperature and atmospheric pressure, without observing any degradation or alteration of the magma composition. To increase the storage time, it is also possible to store the charged magma composition under vacuum (i.e., at a pressure lower than atmospheric pressure, typically 0.3 bar under an inert atmosphere, or 0.8 bar under air) and / or under inert conditions (N2 or Ar atmosphere). The invention also relates to a hermetically sealed container holding the charged magma composition according to the invention.This container can be under inert conditions (i.e., an atmosphere of N2 or Ar in the container), under vacuum (for example at a pressure ranging from 0.3 bar to 0.8 bar) or under ambient air.

[0131] The invention also relates to a method for preparing a charged magma composition according to the invention. This method comprises, preferably consists essentially of, and better consists of the following steps:

[0132] a) to have a polystyrene mass as described above,

[0133] b) have at least one charge as described above,

[0134] c) mix the polystyrene magma and 25% to 75% by weight of at least one filler relative to the weight of the polystyrene magma and filler(s), in order to obtain a charged magma composition.

[0135] At step a), the magma is as described above, and / or can be obtained according to the process described above.

[0136] Step b) of the process for preparing the loaded magma composition according to the invention consists of having at least one charge. Such a charge is as detailed above. Optionally, this charge can be shaped (i.e., ground or crushed, for example) before its use.

[0137] Step c) of the process for preparing the loaded magma composition according to the invention comprises mixing the polystyrene magma with 25% to 75% by weight of at least one filler, relative to the weight of the magma and filler mixture, preferably 28% to 72% by weight, preferably 30% to 62% by weight, and even more preferably 40% to 53% by weight. In other words, in this step, the filler(s) and the magma are mixed in a filler / magma mass ratio of 0.39 to 9, preferably 0.4% to 2.5%, and even more preferably 0.4% to 0.53%. Advantageously, in this step, the filler(s) and the polystyrene are mixed in a mass ratio of 0.3 to 4, and preferably 0.4 to 3.7. The polystyrene magma and at least one filler are as detailed above. This mixture can be produced by any technique known to those skilled in the art, and in particular by mechanical stirring.The mixing speed can vary depending on the nature and concentration of the fillers, and therefore on the viscosity of the mixture. The mixing of the magma and the filler(s) can be carried out in different ways: either the magma is added to the filler(s), or, preferably, the filler(s) is / are added to the magma. Regardless of the method chosen, the addition can be done all at once, sequentially, or continuously over a set period. If the composite material contains several fillers, these are mixed into the magma either all at once or one after the other. The exact conditions (mixing speed and time, order and method of addition) can be determined by a person skilled in the art and do not affect the resulting composite material as long as the mixing continues until a homogeneous, or nearly homogeneous, distribution of the fillers is achieved in the magma.

[0138] According to a particular embodiment, in step c), the charge, or at least one of the charges, may be pre-mixed with the transformation composition before being brought into contact with and mixed with the magma. This embodiment is particularly advantageous when the charge(s) are in powder or chip form, as it prevents their dispersion into the atmosphere during mixing. According to this embodiment, 50 mL to 1000 mL, preferably 100 mL to 500 mL, even better 150 mL to 250 mL, and more preferably 200 mL of transformation composition per kg of charge(s).

[0139] According to a particular embodiment, step c) of the process for preparing the loaded magma composition also includes mixing 25 kg to 0.40 kg per kg of polystyrene magma, preferably 0.28 kg to 0.36 kg, of at least one chlorinated solvent, as detailed above, with the polystyrene magma and the filler(s). Advantageously, according to this embodiment, the at least one chlorinated solvent is pre-mixed with the magma before mixing with the filler(s). Although not preferred, it is possible to first mix the magma and the filler(s), and then mix this mixture with the at least one chlorinated solvent, or to directly mix the magma, the at least one filler, and the at least one chlorinated solvent together.

[0140] According to a particular embodiment, step c) of the process for preparing the filled magma composition also includes mixing at least one additive, as detailed above, with the polystyrene magma and the filler(s). The order in which the at least one additive is mixed with the polystyrene magma, the at least one filler, and optionally the at least one chlorinated solvent, is irrelevant for obtaining the composite material.

[0141] The invention also provides a composite material comprising polystyrene and one or more fillers. More specifically, the composite material is obtained by mixing a polystyrene magma with at least one filler. The polystyrene, the polystyrene magma, and the filler(s) are as detailed above. The composite material according to the invention comprises one or more fillers, in a filler / polystyrene mass ratio ranging from 0.3 to 4, preferably from 0.4 to 3.7. It has been found that the mechanical strength of the resulting composite material is inversely proportional to the filler content. Therefore, depending on the intended application, a person skilled in the art can adjust the filler content in the composite material to obtain the desired mechanical strength.

[0142] In a particular embodiment, the composite material also comprises at least one chlorinated solvent as detailed above. According to this embodiment, the mass ratio of chlorinated solvent(s) to polystyrene in the composite material ranges from 0.25 to 0.6, and preferably from 0.28 to 0.5. This embodiment is particularly advantageous when the mass ratio of filler(s) to polystyrene in the composite material is greater than 1.5.

[0143] In one embodiment, the composite material also comprises one or more additives, as detailed above. According to this embodiment, the composite material according to the invention comprises one or more additives in a total additive content of less than or equal to 10% by weight, and preferably in a content of less than or equal to 5% by weight.

[0144] According to a first particular embodiment, the composite material comprises, preferably consists essentially of, and even better consists of:

[0145] - polystyrene as defined above,

[0146] - one or more fillers, in a mass ratio of filler(s) to polystyrene ranging from 0.3 to 4, preferably from 0.4 to 3.7, and

[0147] - possibly one or more additives, preferably in a content of less than 10% by weight, relative to the total weight of the composite material.

[0148] According to a second particular embodiment of the invention, the composite material comprises, preferably consists essentially of, and even better consists of:

[0149] - polystyrene as defined above,

[0150] - one or more filler(s), in a mass ratio of filler(s) / polystyrene ranging from 0.3 to 4, preferably from 0.4 to 3.7,

[0151] - one or more chlorinated solvent(s), in a mass ratio of chlorinated solvent(s) / polystyrene ranging from 0.25 to 0.6, preferably from 0.28 to 0.5 kg, the chlorinated solvent(s) being preferably chosen from trichloroethylene, tetrachloroethylene and their mixture, and - possibly one or more additives, preferably in a content of less than 10% by weight, relative to the total weight of the composite material.

[0152] In other words, the composition of the composite material according to the invention differs from that of the magma composition charged only by the content of the solvents (solvent(s) of the transformation composition and possibly chlorinated solvent(s)) and / or by the content of the alcohol(s) of the transformation composition.

[0153] The composite material according to the invention has the advantage of being resistant to moisture and water, meaning that it does not deteriorate or alter in the presence of water or moisture. It can therefore be used to manufacture parts or structures intended for outdoor use, and thus subject to weathering.

[0154] The invention also relates to a method for preparing a composite material according to the invention. The method for preparing such a composite material comprises, preferably consists essentially of, the following successive steps:

[0155] 1) to have a polystyrene magma containing at least 70% by weight of polystyrene, relative to the weight of the magma, said polystyrene being in an amorphous, non-expanded state,

[0156] 2) to have at least one charge,

[0157] 3) Mix the polystyrene magma with 25% to 75% by weight of at least one filler, relative to the weight of the polystyrene magma and filler(s), to obtain a charged magma composition, and

[0158] 4) dry the charged magma composition.

[0159] Steps 1), 2) and 3) correspond respectively to steps a), b) and c) of the process for preparing the charged magma composition according to the invention and as detailed above.

[0160] During steps 1) and 2), the polystyrene magma and at least one filler are as detailed above.

[0161] Similar to step c) of the process for preparing the loaded magma composition according to the invention, step 3) comprises mixing the polystyrene magma with 25% to 75% by weight of at least one filler, relative to the weight of the magma and filler mixture, preferably 28% to 72% by weight, preferably 30% to 62% by weight, and even better 40% to 59% by weight. In other words, during this step, the filler(s) and the magma are mixed in a filler / magma mass ratio preferably ranging from 0.39 to 9, preferably 0.4% to 2.5%, and even better 0.33% to 0.53%. Advantageously, at this stage, the filler(s) and the polystyrene are mixed in a mass ratio of 0.3 to 4, and preferably 0.4 to 3.7. The polystyrene mixture and the at least one filler are as detailed above. This mixing can be carried out by any technique known to those skilled in the art, and in particular by mechanical stirring.The mixing speed can vary depending on the nature and concentration of the fillers, and therefore on the viscosity of the mixture. The mixing of the magma and the filler(s) can be carried out in different ways: either the magma is added to the filler(s), or, preferably, the filler(s) is / are added to the magma. Regardless of the method chosen, the addition can be done all at once, sequentially, or continuously over a set period. If the composite material contains several fillers, these are mixed into the magma either all at once or one after the other. The exact conditions (mixing speed and time, order and method of addition) can be determined by a person skilled in the art and do not affect the resulting composite material as long as the mixing continues until a homogeneous, or nearly homogeneous, distribution of the fillers is achieved in the magma.

[0162] According to a particular embodiment, in step 3, the feed, or at least one of the feeds, may be pre-mixed with the processing composition before being brought into contact with and mixed with the magma. This embodiment is particularly advantageous when the feed is in powder or small particle form, especially sawdust or wood chips, as it prevents its dispersion into the atmosphere during the mixing operations. According to this embodiment, 50 mL to 1000 mL, preferably 100 mL to 500 mL, even better 150 mL to 250 mL, and more preferably 200 mL of processing composition per kg of feed is added.

[0163] According to one particular embodiment, step 3) of the composite material preparation process also includes mixing 25 kg to 0.40 kg per kg of polystyrene magma, preferably 0.28 kg to 0.36 kg, of at least one chlorinated solvent, as detailed above, with the polystyrene magma and the fillers. In other words, according to this embodiment, the mass ratio of chlorinated solvent(s) to magma in the filled magma composition obtained at the end of step 3) is 0.25 to 0.4, preferably 0.28 to 0.36. Advantageously, according to this embodiment, the mass ratio of chlorinated solvent(s) / polystyrene in the composition of the loaded magma obtained at the end of step 3) is 0.25 to 0.57, preferably 0.28 to 0.51. This embodiment is particularly advantageous when the content of fillers in the composition of the loaded magma is greater than 60% by weight relative to the total weight of magma and filler(s).Advantageously, according to this embodiment, at least one chlorinated solvent is pre-mixed with the magma before mixing with the filler(s). Although not preferred, it is possible to first mix the magma and the filler(s), then mix this mixture with at least one chlorinated solvent, or alternatively, to directly mix the magma, the filler, and the chlorinated solvent together.

[0164] According to a particular embodiment, step 3) of the composite material preparation process also includes mixing at least one additive, as detailed above, with the polystyrene magma and the filler(s). The order in which the at least one additive is mixed with the polystyrene magma, the at least one filler, and optionally the at least one chlorinated solvent, is not important for obtaining the composite material.

[0165] At the end of step 3) a magma composition is obtained, known as the charged magma composition. This composition comprises only polystyrene magma, one or more fillers, possibly one or more chlorinated solvents, and possibly one or more additives, in the proportions detailed above.

[0166] Step 4) of the composite material preparation process according to the invention comprises drying the filled magma composition. This drying can be carried out at atmospheric pressure and ambient temperature or by heating to a temperature preferably below the boiling point of each of the solvents (chlorinated or non-chlorinated), alcohols, lubricants, and additives present in the filled magma composition. For example, heating to 40°C, 45°C, or 50°C can be carried out to accelerate the drying step. This heating step is carried out until the weight of the resulting composite material remains constant. Furthermore, advantageously, no air bubbles are trapped in the composite material during this drying step. No vibration or shaking step is necessary for this, but such a step could be considered without departing from the scope of the invention.

[0167] The invention also relates to a part made of composite material produced from a composite material according to the invention, or produced from a composite material obtained according to the process according to the invention.

[0168] The invention also relates to a method for preparing such a part from composite material. Such a method comprises, preferably consists essentially of, and better still consists of, the following successive steps: i) having a charged magma composition according to the invention, or obtained according to the method of the invention,

[0169] ii) place the loaded magma composition into a mold having the desired shape of the part,

[0170] iii) dry the charged magma composition, and

[0171] iv) demold the resulting composite material part.

[0172] In step ii), the charged magma composition can be introduced into a mold using any technique known to those skilled in the art. For example, the composition can be poured into a mold and then possibly pressed to distribute the charged magma composition throughout the mold. Alternatively, the charged magma composition can be introduced into a mold by applying overpressure or underpressure.

[0173] Step iii) of drying the filled magma composition can be carried out in the same way as step 4) of the composite material preparation process according to the invention, that is, preferably at atmospheric pressure and ambient temperature or with slight heating. Advantageously, within the scope of the invention, no deformation is observed during drying: the dimensions of the composite part are substantially identical to those of the mold.

[0174] Step iv) of the process for preparing a part made of composite material consists of demolding the part obtained after drying in step iii). This step can be carried out using any technique known to a person skilled in the art, and will not be detailed here.

[0175] The process for preparing a part made of composite material may further include a step (v) subsequent to step (iv), preferably comprising machining the resulting part to give it the desired shape and / or appearance. This step may, for example, include polishing the part, drilling, grinding, cutting, sawing, milling, or joining it to another part by any known means.

[0176] The invention also relates to a part made of composite material obtained in accordance with the process according to the invention.

[0177] Finally, the invention also relates to a method for recycling a part made of composite material according to the invention, or obtained according to the method of the invention, comprising, preferably consisting essentially of, preferably consisting of, the following successive steps:

[0178] I) to have at least one part made of composite material conforming to the invention, or obtained in accordance with the process according to the invention, II) to have a transformation composition as described above, III) to bring the at least one part made of composite material into contact with the transformation composition,

[0179] IV) separate the polystyrene magma on one side and at least one charge on the other.

[0180] In step I), at least one composite material component may have been used in various applications (food or non-food packaging, insulation, etc.). According to one embodiment, this component may be broken, ground, or crushed to form small parts or fragments, whether regular or irregular in shape, the largest dimension of which is advantageously less than 20 cm. The following description refers to at least one composite material component, but it is clear that fragments obtained by breaking, grinding, or crushing could also be used in this recycling process.

[0181] In step III), the contacting of at least one part made of composite material and the transformation composition is preferably carried out by immersing at least one part made of composite material in the transformation composition.

[0182] Alternatively, it is also possible to spray the transformation composition onto at least one composite material part without departing from the scope of the invention. Upon contact, the polystyrene takes on a non-expanded and amorphous form characteristic of magma. This can again be observed by a significant reduction in volume and the formation of a flexible, non-sticky paste, as in step C) of the magma preparation process.

[0183] In step IV), the separation between the polystyrene magma on the one hand and at least one filler on the other can be achieved by removing the supernatant, for example by aspiration or filtration. Thus, at the end of this recycling process, the polystyrene magma, which may contain the transformation composition, and the fillers, the transformation composition, possibly at least one chlorinated solvent, and possibly at least one additive, as described above, are recovered on the one hand.

[0184] In a particular embodiment, the resulting magma is filtered to remove certain impurities. This optional step can be carried out using a hopper or a filter, for example, the diameter or pore size of which can be adjusted by a person skilled in the art. It is also possible to apply pressure or vacuum at this stage, using techniques known to those skilled in the art. Examples

[0185] Example 1: Preparation of composite materials according to the invention from expanded polystyrene

[0186] To produce the composite material according to the invention, the following were used: - expanded polystyrene from packaging for household appliances, reduced to pieces whose largest dimension is less than 20 cm,

[0187] - transformation composition: 96.5% by volume of acetone (99.8% marketed by Brenntag), 1.5% by volume of glycerin (99.5%, marketed by Brenntag), and 2% by volume of isopropanol (99.9%, marketed by Brenntag), relative to the total volume of the transformation composition,

[0188] - tetrachloroethylene (100%, marketed by Brenntag),

[0189] - Fir and beech sawdust as plant-based filler (originating from woodworking machining residues),

[0190] - diatomaceous earth (marketed by Imerys under the name Absodan) as a mineral filler,

[0191] - steel as metallic filler (from metallic residues of milling and metal sawing machines),

[0192] - Magnesium oxide (99%, marketed by the company MYLEORE) as a ceramic filler.

[0193] First, an initial polystyrene magma (Ml) was obtained by spraying 8.57 kg of the transformation composition onto 11.43 kg of expanded polystyrene. After a few minutes, structural collapse was observed. The magma was then dewatered by compressing it and passing the transformation composition through a conical screw press nested inside a complementary conical sleeve. The gap between the screw press and the sleeve was such that only the transformation composition passed through. Following dewatering, 20 kg of polystyrene magma (Ml) were recovered and then transferred to a 60 L polyethylene drum.

[0194] A second polystyrene magma, M2, was then prepared by spraying 8.57 kg of the transformation composition onto 11.43 kg of expanded polystyrene. After a few minutes, structural collapse was observed. The magma was then dewatered by compressing it and passing the transformation composition through a conical screw press nested inside a complementary conical sleeve. The gap between the screw press and the sleeve was such that only the transformation composition passed through. Next, 2.63 L of tetrachloroethylene were poured into the drum containing the magma, without stirring. After 5 minutes, the mixture was mechanically stirred (200 rpm for 8 minutes, then 400 rpm for 2 minutes), resulting in the production of magma M2.

[0195] Next, the feedstock was added under agitation to the magma M1 or M2, according to the contents mentioned in Table 1 below (the contents are mass contents relative to the weight of magma and feedstock), and the mixture was mechanically stirred at 200 rpm for 10 min, allowing the loaded magma compositions CMC1 to CMC11 to be obtained.

[0196] Table 1]

[0197] composite material magma Ml (%) magma M2 (%) loads (%)

[0198] CMC1 72 0 fir wood sawdust

[0199] 28

[0200] CMC2 70 0 magnesium oxide

[0201] 32

[0202] CMC3 68 0 steel

[0203] 32

[0204] CMC4 60 0 diatomaceous earth

[0205] 40

[0206] CMC5 60 0 fir sawdust

[0207] 40

[0208] CMC6 60 0 40

[0209] beech sawdust

[0210] CMC7 60 0 40

[0211] steel

[0212] CMC8 47 0 fir sawdust

[0213] 53

[0214] CMC9 0 37 fir sawdust

[0215] 63

[0216] CMC10 0 37 diatomaceous earth

[0217] 63

[0218] CMC11 0 28 fir sawdust

[0219]

[0220] 72

[0221] A photograph of the charged magma composition is shown in Figure 1.

[0222] Magma compositions loaded with CMC1 to CMC11 were introduced into a mold to form plates of varying dimensions and were dried at room temperature and atmospheric pressure for 2 hours. The resulting PI to Ply composite parts, obtained from the CMC1 to CMC11 magma compositions, were then demolded. The P7, P8, P9, and P10 composite parts are shown in Figures 2 to 5.

[0223] The mechanical resistance of the part made of P9 composite material was tested, and it was determined that it can support a weight of 40 kg without deterioration (no elastic or plastic deformation, nor breakage).

[0224] Example 2: Preparation of composite material from crystal polystyrene. To produce the composite material according to the invention, the following were used: - crystal polystyrene from the body of a BIC® brand pen,

[0225] - transformation composition: 96.5% by volume of acetone (99.8% marketed by Brenntag), 1.5% by volume of glycerin (99.5%, marketed by Brenntag), and 2% by volume of isopropanol (99.9%, marketed by Brenntag), relative to the total volume of the transformation composition, and

[0226] - Fir wood sawdust as a filler of plant origin (from machining residues in carpentry).

[0227] First, a polystyrene M3 magma was obtained by spraying 2.3 g of the transformation composition onto 3.4 g of crystal polystyrene. The magma was then dewatered by compressing it and passing the transformation composition through a conical screw press nested inside a complementary conical sleeve. The gap between the screw press and the sleeve was such that only the transformation composition passed through. After dewatering, 5.7 g of polystyrene M3 magma were recovered and then placed in a polyethylene drum.

[0228] Next, 43% by weight of fir sawdust relative to the total weight of magma M3 and fir sawdust were added under agitation to the magma M3, and the mixture was mechanically stirred at 200 rpm for 10 min, allowing the magma composition to be charged with CMC12.

[0229] The CMC12-filled magma composition was introduced into a mold to form a plate, then dried at room temperature and atmospheric pressure for 2 hours. The resulting P12 composite part, made from the CMC12-filled magma composition, was then demolded.

[0230] Figure 6 is a photograph illustrating the pen body used (the cap at the end of the pen was removed prior to the preparation of the magma), the CMC12-charged magma composition, and the P12 composite material part.

Claims

DEMANDS

1. Charged magma composition comprising: - a polystyrene magma containing at least 70% by weight of polystyrene relative to the weight of the polystyrene magma, said polystyrene being in an amorphous, unexpanded state, and - 25% to 75% by weight of one or more fillers, relative to the weight of the polystyrene magma and filler(s).

2. A magma composition loaded according to claim 1, wherein the load(s) are selected from: - plant-based fillers, preferably chosen from wood-based fillers, flax-based fillers, carbon fibers, and mixtures thereof, - mineral fillers, preferably chosen from calcium carbonate, silica, sand, glass wool, rock wool, and mixtures thereof, - metallic fillers, preferably selected from steel, iron, copper, zinc, aluminum, their alloys, and mixtures thereof, - ceramic fillers, preferably selected from oxides, nitrides, carbides, borides, and mixtures thereof, and in particular iron oxide, lead oxide, titanium oxide, magnesium oxide, zirconium oxide, tungsten nitride, titanium nitride, silicon nitride, silicon carbide, tungsten carbide, iron boride, titanium boride, zirconium boride, and mixtures thereof, and - their mixtures.

3. Magma composition loaded according to claim 1 or 2, wherein the load(s) are in the form of powder, chips, fibers, or fragments whose largest dimension is less than or equal to 1 cm.

4. A magma composition loaded according to any one of claims 1 to 3, wherein the polystyrene magma comprises a transformation composition, preferably in a content of at least 15% by weight, preferably from 15% to 50% by weight, preferably from 15% to 40% by weight, preferably from 15% to 25% by weight, and preferably from 17% to 20% by weight, relative to the total weight of the polystyrene magma, said transformation composition comprising at least one solvent, at least one lubricant and at least one alcohol.

5. A magma composition charged according to the preceding claim, wherein the transformation composition comprises, relative to the volume of the transformation composition: - at least one solvent, preferably a solvent, in a content ranging from 92% to 98% by volume, said solvent preferably being acetone, - at least one lubricant, preferably a lubricant, in a concentration ranging from 1% to 2% by volume, said lubricant preferably being glycerin, and - at least one alcohol, in a content ranging from 0.5% to 6% by volume, preferably 1% to 2% by volume, said at least one alcohol being preferably chosen from aliphatic or cycloaliphatic alcohols, linear or branched, comprising 1 to 15 carbon atoms.

6. Magma composition loaded according to any one of the preceding claims, further comprising 0.25 kg to 0.4 kg of at least one chlorinated solvent per kg of magma.

7. Magma composition loaded according to the preceding claim, wherein the chlorinated solvent is selected from trichloroethylene, tetrachloroethylene and their mixture.

8. Magma composition loaded according to any one of the preceding claims, further comprising at least one additive, preferably selected from colorants, flame retardants, UV inhibitors, plasticizers, and mixtures thereof.

9. A method for preparing a magma composition loaded according to any one of claims 1 to 8 comprising the following steps: a) having a polystyrene magma containing at least 70% by weight of polystyrene, relative to the weight of the magma, said polystyrene being in an amorphous, unexpanded state, b) have at least one charge, c) mix the polystyrene magma and 25% to 75% by weight of at least one filler relative to the weight of the polystyrene magma and filler(s), and possibly 0.25 kg to 0.4 kg of at least one chlorinated solvent per kg of magma, in order to obtain a charged magma composition.

10. Container containing the magma composition loaded according to any one of claims 1 to 8, or obtained in accordance with the process according to the preceding claim, said container preferably being hermetically sealed.

11. Composite material comprising: - polystyrene, and - one or more fillers, in a mass ratio of filler(s) / polystyrene ranging from 0.3 to 4.

12. Composite material according to the preceding claim, wherein the filler(s) are selected from: - plant-based fillers, preferably chosen from wood-based fillers, flax-based fillers, carbon fibers, and mixtures thereof, - mineral fillers, preferably chosen from calcium carbonate, silica, sand, glass wool, rock wool, clay, kaolin, quartz, feldspar, and mixtures thereof, - metallic fillers, preferably selected from steel, iron, copper, zinc, aluminum, their alloys, and mixtures thereof, - ceramic fillers, preferably selected from oxides, nitrides, carbides, borides, and mixtures thereof, and in particular iron oxide, lead oxide, titanium oxide, magnesium oxide, zirconium oxide, tungsten nitride, titanium nitride, silicon nitride, silicon carbide, tungsten carbide, iron boride, titanium boride, zirconium boride, and mixtures thereof, and - their mixtures.

13. Composite material according to claim 11 or 12, further comprising at least one chlorinated solvent in a mass ratio of chlorinated solvent(s) / polystyrene of 0.25 to 0.6, said at least one chlorinated solvent being selected from trichloroethylene, tetrachloroethylene and mixtures thereof.

14. A method for preparing composite material according to any one of claims 11 to 13 comprising the following steps: 1) to have a polystyrene magma containing at least 70% by weight of polystyrene, relative to the weight of the magma, said polystyrene being in an amorphous, non-expanded state, 2) to have at least one charge, 3) Mix the polystyrene magma with 25% to 75% by weight of at least one filler, relative to the weight of the polystyrene magma and filler(s), and optionally 0.25 kg to 0.4 kg of at least one chlorinated solvent per kg of magma, in order to obtain a charged magma composition, and 4) dry the charged magma composition.

15. A method according to the preceding claim, comprising a step 2') subsequent to step 2) and prior to step 3), consisting of adding to the at least one 50 mL to 1000 mL charge of a transformation composition per kg of charge(s), preferably 100 mL to 500 mL, and even better 150 mL to 250 mL, said transformation composition comprising at least one solvent, at least one lubricant and at least one alcohol.

16. Part made of composite material according to any one of claims 11 to 13, or of a material obtained according to the process according to claim 14 or 15.

17. A method for preparing a part made of composite material according to the preceding claim, comprising the following steps: (i) to have a magma composition charged according to any one of claims 1 to 8, or obtained in accordance with the process according to claim 9, ii) place the loaded magma composition into a mold having the desired shape of the part, iii) dry the charged magma composition, and iv) demold the resulting composite material part.

18. A method according to the preceding claim, comprising a step v) subsequent to step iv), consisting of machining the resulting composite material part.

19. A process for recycling at least one part made of composite material according to claim 16, or obtained according to the process according to claim 17 or 18, comprising the following steps: I) to have at least one part made of composite material according to claim 17, or obtained in accordance with the process according to claim 18 or 19, II) to have a transformation composition comprising, in relation to the volume of the transformation composition: - at least one solvent, preferably a solvent, in a content preferably ranging from 92% to 98% by volume, said solvent preferably being acetone, - at least one lubricant, preferably a lubricant, preferably with a content ranging from 1% to 2% by volume, said lubricant preferably being glycerin, and - at least one alcohol, preferably with a content ranging from 0.5% to 6% volume, preferably 1% to 2% by volume, said at least one alcohol being preferably chosen from aliphatic or cycloaliphatic alcohols, linear or branched, comprising 1 to 15 carbon atoms, III) bring at least one part made of composite material into contact with the transformation composition, IV) separate the polystyrene magma on one side and at least one charge on the other.

20. A recycling process according to the preceding claim, wherein step IV) of separation is carried out by removing the supernatant by aspiration or filtration.

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