ITMI20121357A1 - RECYCLING PROCESS OF THERMO-COMPOSITE COMPOSITE MATERIALS - Google Patents

Description

DESCRIPTION

"RECYCLING PROCESS OF COMPOSITE MATERIALS

THERMOSET "

Field of the invention

The present invention relates to a process for the recycling of thermosetting composite materials, in particular fiberglass. The invention also relates to the recycled product obtainable from this process.

State of the art

The recycling of plastics has had, in the last decades, a great impulse of growth stimulated by the more and more massive diffusion of the same in our society.

Plastics can be divided into two macro-families: thermoplastics and thermosetting materials.

The diffusion of products in thermosetting material appears modest if compared with other thermoplastic products. Just think of the PET (Polyethylene Terephthalate) bottles; PE (polyethylene) plastic bags; food packaging in PP (polypropylene); and all other widely used polymers (ABS; PA; POM; PS; PC; PMMA; PVC; PU; ...).

However, thermosetting matrix composites are used in a multitude of applications. For example, composites based on polyester, epoxy, acrylic, polyurethane, phenolic and urea resins are used in the following sectors: automotive, transport, construction, nautical, electricity, etc.

Such thermosetting composite materials include a thermosetting resin matrix (for example, polyester), together with reinforcing fibers (for example glass, carbon, aramid fibers, etc.) and possibly also together with inert fillers, such as calcium carbonate and aluminum hydroxide.

The recycling of thermoplastic materials is still technically simple today and resembles the same "system" adopted for metallic materials: it is sufficient to melt them.

Materials with a thermosetting matrix do not have the property of being remelted due to their chemical-physical structure and for this reason they are still considered "landfill inert".

Some recycling attempts have been made in various European and non-European countries.

The most significant experiences in Europe in this direction have been developed by French, German and Norwegian companies. In particular, the French and Germans dedicated themselves to waste from SMC (Sheet Molding Compound) and BMC (Bulk Molding Compound) technologies, while the Norwegians to waste from the nautical sector, mainly processed with spray-up technology.

The solution experimented by the French and Germans is to obtain, by granulation and successive pulverizations, a series of powders and fibers with different granulometry to be reused in the same SMC / BMC process as calcium carbonate supplements. Regarding this procedure, the composition of the starting raw materials (ie production waste) should be emphasized; these in fact contain high quantities of calcium carbonate and modest quantities of glass fiber which, moreover, undergoes a considerable degradation in terms of fiber length after molding. A product produced with SMC or BMC technologies is therefore particularly "easy" to granulate and finely pulverize. The powders obtained from these wastes are comparable with the common calcium carbonate even if they hardly reach particle sizes below 60 microns. It is possible to go below the threshold of 60 microns but the pulverization costs increase significantly. This granulometric difference causes the impossibility of reusing the ground in new products in percentages higher than 5% (on average 3% is used in order not to compromise the aesthetics of the surfaces of the products). However, tests have been conducted that have allowed to reach 20%.

Since the powders are obtained mainly from automotive sector waste (truck bumpers) it is obvious that 3% is too low to be able to reuse all the waste in the production of new products (for example, it is necessary to produce 33 new bumpers to dispose of only one ). It follows that the economic advantage in replacing calcium carbonate with recycled powders is minimal as the price of calcium carbonate is very low.

Since it is difficult to supply powders of thermosetting composite materials at competitive prices compared to the costs of inert fillers, an attempt has been made to mix these powders with widely used thermoplastic polymers, producing mixed composite materials.

The results obtained in the "compounding" with widely used polymers (PP polypropylene and high or low density PE polyethylene) were discrete from a technical point of view even if modest from an economic point of view. The selling price of the powders in fact continues to be in line with that of calcium carbonate although these powders also carry a reinforcing component given by the presence of glass fibers which would justify a minimum added value. Furthermore, doubts persist about the behavior of the resinous part (unsaturated polyester) in thermoplastic matrices which have in fact slowed down the spread of the application at an industrial level, above all because the large compound producers, working with considerable volumes, are reluctant to modify their production cycles.

In Norway we worked starting from scraps deriving from the production of fiberglass boats whose composition differs from the previous one due to the absence of calcium carbonate and a much higher percentage of glass fiber. Beyond the problems related to the machinery for the granulation of these waste (the consumption of the cutting blades is greater due to the presence of glass), the approach to recycling is similar to the previous one, that is to reuse the waste in the same production chain. granulates.

By modifying a common cutting / spraying gun (Spray-up) it was possible to replace the virgin glass yarn with recycled powders. The higher granulometry processable by the modified gun offered the advantage of lower granulation costs. The percentage of recycled materials in the new products is also significantly higher and has reached the maximum level of 30% (this percentage, however, refers only to the areas where this technology is used, for example fillers with a low level of mechanical resistance).

The economic results of these two experiences are, unfortunately, modest because they have not been able to give sufficient added value to the recycled product; It is certainly true, however, that considering the savings obtained from not transferring waste to landfills, the overall balance has improved in any case.

Recently, recycling methods of thermosetting matrix composite materials have been proposed in which the material can be used in the kilns of cement factories. In the recycling of thermosetting composite materials through cement factories, most of the material is transformed into raw material for the production of cement, while a small part of organic material is burned. The process therefore translates into an energy recovery (Position Paper on the recycling of thermosetting composite components by EUPC (European Plastics Converters); EUCIA (European Composites Association); ECRC (European Composites Recycling Service Company) and Assocompositi).

In light of the most recent EU provisions on environmental sustainability, which will inevitably lead to an increase in disposal costs, a new solution for the recycling of thermosetting matrix composite materials appears at least necessary.

The recycling process of these composites should allow to overcome the known problems, that is, it should be able to allow the composite material to be recycled in its entirety (without the need for initial separations into its constituents), to reduce the recycling costs of such materials, providing products with technical characteristics such as to have sufficient added value on the market.

Summary of the invention

The present invention responds to these needs by providing a method for recycling a composite material with a thermosetting matrix coming from the waste of industrial processes and / or from end-of-life products, in which the thermosetting composite material to be recycled is mixed, after shredding with a thermosetting resin. Furthermore, the process of the present invention provides for the use of a thickening agent which allows to control the rheology of the entire system and therefore allows to process the material to be recycled in a screw extruder.

The method of the invention can also be defined as a method for the preparation of a product based on recycled thermosetting plastic material, as it allows to obtain recycled products of different shapes and sizes that can be used for different purposes, for example for the preparation of plates for industrial roofs, drainage channels, gutters, fixtures, outdoor furniture, furnishings for interiors and exteriors, boards and poles for outdoor constructions (for example for fences) boards, panels, beams, strips, shower platforms, road signs, bushings, pipes, flanges, gears, guard rails, soundproofing barriers.

The process of the invention has the advantage of making it possible to obtain recycled products with a high added value, that is, with better performance than similar products in traditional materials, such that they can be used for different uses. Furthermore, the process of the invention allows the entire waste material to be recycled without requiring prior separation of its constituents.

Brief description of the figures

The detailed description of the invention is carried out below also with reference to the following figures: - Figure 1 shows an extruder with a screw used for the realization of the recycling product of the present invention;

- Figure 2 shows an extruder with two augers used for the realization of the recycled product of the present invention.

Detailed description of the invention

The present invention relates to a process for the recycling of a thermosetting matrix composite material comprising the steps of:

a) subjecting said composite material to a thermosetting matrix to grinding;

b) mixing said shredded material with a thermosetting resin and with an organic or inorganic thickening agent;

c) extruding the mixture obtained in point b) with an extruder to at least one screw.

The composite material with thermosetting matrix subjected to recycling with the process of the invention is preferably a composite material which comprises a matrix chosen from: polyester resin, epoxy resin, polyurethane resin, phenolic resin, urea resin, acrylic resin, vinyl-ester resin , alkyl resin, melamine resin. The preferred resin is polyester resin.

The polyester resin can be preferably chosen from: orthophthalic, isophthalic, isophthalic, neopentylglycol, dicyclopentadiene resin.

The composite material with a thermosetting matrix subjected to recycling with the process of the invention preferably comprises a reinforcing fiber chosen from: a glass fiber, a carbon fiber, an aramid fiber, a basalt fiber, a vegetable fiber or vegetable origin, for example a coconut fiber or a flax fiber. The preferred fiber is glass fiber.

In one embodiment, the thermosetting matrix composite material subjected to recycling with the process of the invention can also comprise one or more inert fillers, for example calcium carbonate, aluminum hydroxide, quartz, bentonites, woods, hollow glass microspheres and / or thermoplastic material (for example PVC, acrylates etc.).

In a particularly preferred embodiment, the thermosetting composite material subjected to the recycling process of the invention comprises a polyester resin matrix, a glass fiber and, optionally, an inorganic filler (for example, chosen between calcium carbonate and hydroxide of aluminum).

Even more preferably, the thermosetting matrix composite material subjected to the recycling process of the invention is glass fiber reinforced polyester (PRFV), commonly called fiberglass.

Preferably, the thermosetting matrix composite material subjected to the recycling process of the invention comprises from 40% to 80% by weight of thermosetting resin (for example, polyester) and from 20% to 60% by weight of reinforcing fibers, preferably 25% to 30% by weight of reinforcing fibers (for example, glass fibers).

The composite material with a thermosetting matrix subjected to recycling in this process can be a waste material from industrial processes, for example waste, non-conforming parts, defective parts, sprues, purges; or it can be an end-of-life product, for example car doors, truck bumpers, isothermal trailers, electrical insulators, electrical cabinets, ducts, pultruded beams, industrial covers, tanks, grids, profiles, boat hulls, molds for the hulls of boats, bushings, pipes, fishing rods, aeronautical and aerospace components, wind turbines.

Preferably, this material is a fiberglass product, preferably chosen from: an industrial roof or a boat hull.

The shredding according to step a) can take place either through a system based on the principle of cut or impact. Preferably, the shredding takes place through the use of a shredder selected from: a hammer mill, a mill with rotating blades, a ball / marble mill, a disc pulverizer and a grinder. As for the shredded, the smaller the size (granulometry), the better the mechanical performance. Furthermore, the smaller the particle size, the greater the useful surface for the transmission of stresses from the resin matrix to the reinforcement.

The shredded composite material can be considered as a collaborating inert material, since, by chemically binding to the thermosetting resin matrix added in step b), and being itself reinforced with a fiber, it collaborates in the transmission of stresses in the recycled material obtained at the end of the recycling process.

The best mechanical performance can be obtained by suitably mixing different granulometries of shredded material also to reduce the quantity of new thermosetting resin to be added and, therefore, the cost of the product.

A larger size of the shredded composite material will be more visible in the final product obtained from the recycling process. It follows that if you want to obtain a material that resembles stones and / or marbles, especially if dyes are added to the mixture, it will be necessary to maintain a large size.

The size of the shredded material can be of so-called fine powders and so-called coarse powders. For example, the size of fine powders does not exceed 5 mm; the size of coarse powders is greater than 5 mm.

The mixing of the shredded material with the thermosetting resin can be carried out using both a continuous mixer (for example, a single-shaft, double-shaft, vane, propeller mixer) or in discontinuous (for example, concrete mixers, rotary arm mixers / orbiting, kneading machines with crankshafts). Preferably, the mixing takes place at room temperature and atmospheric pressure, generating minimal quantities of heat by friction. The size of the mixer will be adapted to the required productivity according to the type of material desired. A continuous mixer is preferably used. Said mixer comprises two shafts equipped with specially oriented vanes, which mix the components in the tank by sliding them towards the opening on the front bottom. In this way, a direct feed of the mixture into the feed mouth of the extruder is achieved.

The shredded thermosetting matrix composite material is mixed, in step b), with a thermosetting resin having the same chemical nature of the matrix of the same, or having a chemical nature compatible with the matrix of the same. This thermosetting resin is preferably chosen from: polyester resin, epoxy resin, polyurethane resin, vinyl ester, phenolic resin, urea resin.

The polyester resin can be preferably chosen from: orthophthalic, isophthalic, isophthalic, neopentylglycol, dicyclopentadiene resin.

For example, if the thermosetting matrix composite material to be subjected to the recycling process of the invention has a polyester resin matrix, the thermosetting resin added in step b) will preferably be a polyester resin. Alternatively, the thermosetting resin added in step b) can be chosen from polyester resin, epoxy resin, polyurethane resin, vinyl ester, phenolic resin, urea resin.

The thermosetting resin is mixed with the shredded composite material in quantities from 1% to 60% by weight, preferably between 3.5% by weight and 20% by weight. Consequently, these are the percentages of new thermosetting resin (i.e., not coming from recycled materials) that will be found in the final product, i.e. in the recycled material obtained at the end of the recycling process.

The quantity of shredded composite material subjected to the recycling process of the invention, present in the final product (i.e. in the recycled material obtained at the end of the recycling process) will be approximately between 40% and 99% by weight, preferably between 80% and 96.5% by weight.

During the mixing step, at least one thickening agent is added.

The thickening agent is preferably selected from: melamine, magnesium oxide, aluminum hydroxide, calcium carbonate and glass microspheres (preferably hollow), preferably having a diameter not exceeding 120 Î1⁄4Ï € Îù, more preferably from 30 at 70 pm.

The thickening agent is preferably added in an amount comprised between 0.5% and 70%, preferably between 0.9% and 16% by weight with respect to the thermosetting resin. For example, in the case of magnesium oxide, the amount is between 0.5% and 2% by weight, preferably between 0.8% and 1.3% by weight with respect to the thermosetting resin. For example, in the case of glass microspheres, the amount is between 15% and 50% by weight, preferably between 20% and 40% by weight with respect to the thermosetting resin.

The thickening agent serves to modulate the rheology of the mixture and therefore the possibility that the latter can be processed in an extruder.

At least one of the following additional additives is preferably added to the mixture of thermosetting matrix composite material, thermosetting resin and thickening agent:

at least one catalyst preferably selected from organic peroxides and / or photoinitiators;

at least one accelerating agent preferably selected from cobalt octoate and / or diethylacetoacetamide;

at least one inhibitor preferably selected from benzophenone and / or terbutylcatechol.

The organic peroxides are preferably selected from: acetylacetone, methylethylketone, tertialbutyl perbenzoate, benzoyl peroxide, isopropylpercarbonate. Depending on the catalyst molecule used, crosslinking trigger temperatures from 20 ° C to 120 ° C can be obtained.

Alternatively, it is possible to use photoinitiators selected from: trimethylbenzoyldiphenylphosphines and aidroxyketone, which trigger cross-linking of the thermosetting resin in the presence of UV radiation with a wavelength preferably between 340 and 420 nm. In this case, the cross-linking effect is limited to the outermost layers of the product, where the UV rays are able to penetrate. For this reason this solution is applicable and preferable for low thickness products (max 10-15 mm).

In a preferred form of the present invention, this catalyst is a mixed peroxidophotoinitiator system.

The catalyst is preferably added to the mixture in an amount comprised between 0.1% and 5% by weight, preferably between 0.5% and 2% by weight on the thermosetting resin.

The accelerating agent is preferably added to the mixture in an amount lower than or equal to 0.3% by weight on the thermosetting resin.

The inhibitor is preferably added to the mixture in an amount equal to or less than 0.02% by weight on the thermosetting resin.

In a preferred form of the invention, at least one further component is added to the mixture selected from: glass fibers, inert fillers, dyes (for example, micronized pigments in powder or paste), UV absorbers (for example 2-hydroxy-4- n-octoxybenzophenone), additives, such as flame-retardant agents, wetting agents, dispersants, thixotropics, air-repellents, antimicrobials), antistatic agents, other monomers (for example, styrene, monomethyl methacrylate, etc.).

When these further additives are present, they are added in quantities from 0.5% to 20% by weight on the thermosetting resin.

In a preferred embodiment, it is possible to add a functional filler, preferably selected from graphite, polytetrafluoroethylene (PTFE), flame-retardant fillers (for example chosen from: melamine), aluminum hydroxide and antimony salts. Graphite and PTFE give the product obtained with the recycling process self-lubricating properties; they are therefore useful in the production of bushings or recycling gears.

The functional filler, if present in the mixture, is added in a quantity between 10 and 30% by weight with respect to the sum of the new thermosetting resin and the thermosetting resin contained in the shredded composite material.

The shredded thermosetting matrix composite material, the thickening agent, the thermosetting resin and any further additives can be pre-dosed and fed into the mixer at the same time. Alternatively, continuous dosing systems can be used for granular and / or powder solids (for example, gravimetric, belt, screw, disc, pneumatic, etc.) and for liquids (for example, dosing pumps). In the case of continuous dosing, the solid components start from, which will be wetted by the liquid components transported with suitable pipes as they advance into the mixer basin.

The kneaded mixture (slurry) prepared by the mixer subsequently enters an extruder with at least one screw where it is subjected to extrusion.

In a preferred embodiment, with reference to Figure 1, the extruder 1 comprises an auger 2, a feeding mouth 3, from which the mixture to be extruded enters the extruder, and a perforated plate (or die or die) 4 , located at the entrance to the degassing chamber 5.

The perforated plate 4 comprises holes whose size and shape vary according to the consistency of the dough and therefore to the proportions between the various ingredients of the mixture to be extruded. The holes reduce the mixture into pieces of various sizes and shapes, depending on the size and shape of the corresponding holes. The pieces of mixture leaving the plate are pushed, by means of the screw 2, towards the degassing treatment which takes place inside the degassing chamber 5.

Therefore, the mixture extrusion step c) preferably comprises a first densification step of the mixture which takes place in the auger section comprised between the feeding mouth 3 and the perforated plate 4 (densification chamber 5a). The mixture is compacted and at the same time transported by the screw to the perforated plate 4.

The perforated plate reduces the mixture into pieces, thus increasing the free surface through which the air contained in the dough can escape.

The degassing chamber 5 comprising a suction system 6 with which the vacuum is applied (for example by means of a vacuum pump). The application of vacuum, together with the large exposed surface of the pieces of mixture and their modest thicknesses, determines an easy and fast elimination of the air.

After degassing, the mixture is transported by the screw 2 to the accumulation area of the extruder 7 from which it flows through the outlet 8. In a particularly preferred form, the extrusion is carried out by means of an extruder 9 comprising two screws 10 and 11 (see Fig. 2). The mixture obtained from the mixer enters the first auger 10 through the feed mouth 12 and is densified and pushed up to the perforated plate 13 which delimits the entrance to the degassing chamber 14. The perforated plate includes holes which reduce the mixture into pieces (of shape and size corresponding to the shape and size of the holes) which fall towards the bottom of the degassing chamber 14, meeting the second auger 11. The degassing chamber 14 performs the same function as the degassing chamber 5 of figure 1. Therefore, an aspiration system 15 is applied to the degassing chamber (for example, a vacuum pump) which by generating the vacuum causes the elimination of the air from the mixed mixture reduced to pieces.

The second screw 11 transports the mixture to the accumulation area of the extruder 16 from which it flows through the outlet 17.

The extruder with at least one screw preferably works at room temperature and atmospheric pressure (except in the degassing chamber, where the vacuum is created), generating heat inside it due to the friction between the dough and the surface. of the screw / cochlea.

Once it has come out of the extrusion mouth 8, 17, the extruded mixture can be subjected to shaping, for example by molding or lamination, or made to harden directly as it exits the mouth through a suitably shaped and heated die (the temperature will be the useful one. for triggering the crosslinking by the catalyst).

Alternatively, the mixture leaving the extruder can be placed on the market before forming, which will be carried out directly by the customer according to their needs. In this case the product leaving the extruder can be defined as molding mass. The molding mass will then be subjected to forming and crosslinking by applying heat to obtain a final product having the desired shape.

The recycling process of the invention allows to obtain a recycled thermosetting composite material comprising up to 99% by weight of recycled thermosetting matrix composite material (such as for example end-of-life products or waste from industrial processing in thermosetting composite material). Preferably the amount of recycled thermosetting matrix composite material is between 60% and 80% by weight, more preferably from 50% to 60% by weight in the final recycled product.

The recycled thermosetting composite material obtainable with the recycling process of the invention is preferably obtained starting from industrial processing waste and / or end-of-life products based on thermosetting matrix composite materials, in which the preferred thermosetting matrix is ̈ the polyester and the reinforcing fibers are glass or carbon fibers, preferably glass fibers.

Preferably, the recycled thermosetting composite material obtainable with the recycling process of the invention is obtained starting from a fiberglass product, preferably from boat hulls or industrial fiberglass covers.

In another aspect, the invention also relates to the use of the recycled thermosetting matrix composite material obtainable with the process of the invention for the production of recycled products having different shapes and sizes that can be used for different purposes, for example for the preparation of plates for industrial roofs, drainage channels, gutters, fixtures, outdoor furniture, furnishings for interiors and exteriors, boards and poles for outdoor constructions (for example for fences), boards, panels, beams, strips, shower platforms, etc.

The invention also relates to these manufactured articles obtained starting from the recycled thermosetting matrix composite material obtainable by means of the recycling process of the invention, after crosslinking of the material. The crosslinking of the material, which can remain latent for some time depending on the reciprocal relationship between catalyst and reaction inhibitor, can take place for example during the forming step of the material, that is, for example during molding. In fact, molding is normally hot and the application of heat triggers the crosslinking reaction and, therefore, the hardening of the recycled material in the desired shape.

Once hardened, the recycled product preferably has the following mechanical characteristics: a tensile strength higher than 30 MPa, preferably higher than 100 MPa (measured according to the UNINISO 527-1 standard), a deformation at the unit breaking load of between 1 and 5%, preferably between 2 and 4% (measured according to the UNINISO 14125 standard) and a flexural strength greater than 150 MPa (measured according to the UNINISO 527-1 standard).

Claims (20)

CLAIMS 1. Process for the recycling of a thermosetting matrix composite material comprising the steps of: a) subjecting said composite material to a thermosetting matrix to grinding; b) mixing said shredded material with a thermosetting resin and with an organic or inorganic thickening agent; c) extruding the mixture obtained in point b) with an extruder to at least one screw. 2. Process according to claim 1, in said thermosetting matrix it is selected from: polyester resin, epoxy resin, polyurethane resin, phenolic resin, urea resin, acrylic resin, vinyl ester resin, alkyl resin, melamine resin, preferably polyester resin. 3. Process according to claim 1, wherein said polyester resin is selected from: orthophthalic, isophthalic, isophthalic, neopentylglycol, dicyclopentadiene resin. 4. Process according to any one of claims 1 to 3, wherein said composite material with a thermosetting matrix comprises a reinforcing fiber selected from: a glass fiber, a carbon fiber, an aramid fiber, a basalt fiber, a fiber vegetable or of vegetable origin, preferably a glass fiber. 5. Process according to any one of claims 1 to 4, wherein said composite material further comprises one or more inert fillers, chosen from: calcium carbonate, aluminum hydroxide, quartz, bentonites, woods, hollow glass microspheres and / or a thermoplastic material, preferably polyvinyl chloride (PVC) or acrylates. 6. Process according to any one of claims 1 to 5, wherein said composite material comprises a polyester resin matrix, a glass fiber and, optionally, an inorganic filler selected from calcium carbonate and aluminum hydroxide. 7. Process according to any one of claims 1 to 6, wherein said composite material is fiberglass reinforced polyester (PRFV). 8. Process according to any one of claims 1 to 7, in which said composite material is selected from a waste material from industrial processes, preferably waste, non-conforming pieces, defective pieces, sprues, purges; or an end-of-life product, preferably car doors, truck bumpers, isothermal trailers, electrical insulators, electrical cabinets, ducts, pultruded beams, industrial covers, tanks, grids, profiles, boat hulls, molds for boat hulls, bushings , pipes, fishing rods. 9. Process according to any one of claims 1 to 8, wherein said thermosetting resin added in step b), has the same chemical nature as the thermosetting matrix of said composite material, or has a chemical nature compatible with the matrix thereof, said thermosetting resin being preferably chosen from: polyester resin, epoxy resin, polyurethane resin, vinyl ester, phenolic resin, urea resin. 10. Process according to claim 9, wherein said composite material comprises a polyester resin matrix and said thermosetting resin added in step b) is a polyester resin. 11. Process according to any one of claims 1 to 10, wherein said thickening agent is selected from: melamine, magnesium oxide, aluminum hydroxide, calcium carbonate and glass microspheres, preferably hollow, preferably having a diameter not exceeding for 120 Î1⁄4Ï € ι, more preferably from 30 to 70 Î1⁄4Ï € ι. Process according to any one of claims 1 to 11, wherein at least one of the following further additives is added to said mixture of thermosetting matrix composite material, thermosetting resin and thickening agent: at least one catalyst preferably selected from organic peroxides and / or photoinitiators; at least one accelerating agent preferably selected from cobalt octoate and / or diethylacetoacetamide; at least one inhibitor preferably selected from benzophenone and / or terbutylcatechol. 13. Process according to any one of claims 1 to 12, wherein said extrusion step c) comprises a step of degassing the mixture by applying vacuum. 14. Process according to claim 13, wherein said degassing step comprises a passage for reducing the mixture into pieces by passing it through a perforated plate placed at the inlet of a degassing chamber of said extruder. 15. Process according to any one of claims 1 to 14, wherein said extruder comprises two augers. 16. Process according to any one of claims 1 to 15, further comprising a step d) for forming the extruded material, preferably by molding. 17. Composite material with thermosetting matrix obtainable by the process according to any one of claims 1 to 16. 18. Material according to claim 17, comprising from 40% to 99% by weight, preferably from 80% to 96.5% by weight, of recycled thermosetting matrix compound material. 19. Product obtainable from the material according to claim 18, after step d) of claim 17, preferably selected from: sheets for industrial roofing, drainage channels, gutters, fixtures, outdoor furniture, furnishings for interiors and exteriors, boards and poles for outdoor construction boards, panels, beams, strips, shower platforms, road signs, bushings, pipes, flanges, gears, guard-rails, soundproofing barriers. 20. Product according to claim 19, having the following mechanical characteristics: a tensile strength higher than 30 MPa, preferably higher than 100 MPa (measured according to the UNINISO 527-1 standard), a deformation at the unit breaking load between 1 and 5%, preferably between 2 and 4% (measured according to the UNINISO 14125 standard) and a flexural strength greater than 150 MPa (measured according to the UNINISO 527-1 standard).