Method for recycling polyvinyl chloride products

Abstract

Method for recycling polyvinyl chloride floor or wall coverings, said polyvinyl chloride forming a first thermoplastic polymer, characterized in that said polyvinyl chloride product comprises at least a second thermoplastic polymer other than polyvinyl chloride, wherein said method comprises the step (S1) of subjecting said polyvinyl chloride products (1) to a solvent-based extraction and the step of separating at least partially said second thermoplastic polymer from said first thermoplastic polymer.

Description

[0001] Method for manufacturing polyvinyl chloride products.

[0002] The present invention relates to recycling polyvinyl chloride (PVC) products. In particular, the invention relates to recycling polyvinyl chloride products such that the polyvinyl chloride polymer obtained from these products may be used for the production of new polyvinyl chloride products. More in particular, these polyvinyl chloride products may relate to floor or wall coverings.

[0003] Although polyvinyl chloride is a thermoplastic polymer, recycling of polyvinyl chloride products is often conceived as being difficult or problematic. This is mainly due to the additives and / or contaminants that PVC products may contain. It is particularly common for most polyvinyl chloride products, especially those which are made from soft PVC, to contain plasticizers. In the state of the art, a class of plasticizers which has been abundantly used are phthalates and their derivatives. Recently however, phthalates have been associated with public health related issues, and in particular with regard to the emission of volatile organic compounds (VOCs). Furthermore, polyvinyl chloride products may contain, amongst other, fillers (for example calcium carbonate), dyes and / or heavy metals, which may contribute to making recycling of these polyvinyl chloride products even more difficult. As the composition of polyvinyl chloride products strongly depends on their specific application, recycling polyvinyl chloride products at their end-of-life stage may be particularly complex.

[0004] EP 1 360 366 discloses a sheet vinyl flooring product having a polyvinyl chloride based structure, wherein a textile layer is bonded to the back surface thereof. The textile layer may be formed at least from fibers of polyethylene terephthalate or polypropylene. Such composite structure may complicate recycling of post-consumer sheet vinyl flooring products.

[0005] The prime object of the present invention is to provide a method for recycling polyvinyl chloride products, with various preferred embodiments offering a solution for the problems associated with the recycling methods of the state of the art. In particular, the invention aims to provide a better and more widely applicable method for recycling polyvinyl chloride products, wherein the recycled polymer may be used to produce new products from polyvinyl chloride.

[0006] JP 2006 / 249423A discloses a method for recovering material from soft polyvinyl chloride products. Crushed soft polyvinyl chloride products are treated with an alcoholic solvent and a non-alcoholic solvent. The non-alcoholic solvent may be carbon dioxide. The non-alcoholic solvent may be in a supercritical state. JP 2007 / 092035 A discloses a similar method for recovering material from lead-containing soft polyvinyl chloride material. The method disclosed in these documents are experimental and / or at small scale. The example in JP’423 concerns recovery of material from a sample of a PVC film, weighing 10 grams. Such films are notoriously differently composed than flooring materials in general. For example, films may be free of filler materials, such as talcum, chalk or other calcium carbonate based materials, while flooring materials are generally highly filled. Films have a uniform composition while flooring materials are generally composed of laminated together portions of a mutually different composition.

[0007] There is a lack of a method for recovering material from waste polyvinyl chloride at an industrial scale, particularly from filled polyvinyl chloride products and / or from polyvinyl chloride products that have a non-uniform composition, for example since they are composed out of laminated layers that have a mutually different composition.

[0008] To this aim, a first independent aspect of the present invention is a method for recycling polyvinyl chloride products, preferably polyvinyl chloride floor or wall coverings, said polyvinyl chloride forming a first thermoplastic polymer, with as a characteristic that said polyvinyl chloride product to be recycled comprises at least a second thermoplastic polymer other than polyvinyl chloride, wherein said method comprises the step of subjecting said polyvinyl chloride products to a solvent-based extraction and the subsequent step of separating at least partially said second thermoplastic polymer from said first thermoplastic polymer. By first performing a step of solvent-based extraction the first polymer, i.e. the PVC, may obtain a more brittle nature which enhances the separation of the first and second polymer in a subsequent step. Practicing such method of recycling is especially interesting in the case where the second polymer forms a substantial portion of said polyvinyl chloride product, for example 5 wt% or more, or even 10 wt% and / or where the second polymer has a substantially higher glass transition or processing temperature than polyvinyl chloride. Preferably, the second polymer forms less than 50 wt%, or even less than 30 wt% of said polyvinyl chloride product. A too high portion of said second polymer may lower the efficiency of the extraction step to an unacceptable level.

[0009] In light of the invention, the term “solvent-based extraction” needs to be interpreted as the separation of one or more components from a mixture by dissolving said one or more components in a suitable solvent. More in particular, one or more soluble components may be separated from one or more insoluble components in a mixture. Preferably said components at least comprise plasticizer, as described in more detail below. The extraction of plasticizer in particular leads to PVC that is more brittle, such that the subsequent separation step may be more effective. For example, in such case, a mechanical separation, i.e. by exerting mechanical force, may be very effective.

[0010] Preferably, said second thermoplastic polymer is or comprises polyethylene terephthalate or polypropylene or polyethylene. Most preferably, the method is practiced for recycling polyvinyl chloride products that comprise at least polyethylene terephthalate as said second thermoplastic polymer. The processing temperatures and further conditions for extruding polyethylene terephthalate are very different from those of polyvinyl chloride. Any content of polyethylene terephthalate is preferably minimized in the reclaimed polyvinyl chloride as it may clog apparatuses and bring about other problems in processing the reclaimed polyvinyl chloride.

[0011] It is clear that the method of the first aspect results in a reclaimed polyvinyl chloride polymer, preferably in particulate form. Preferably the obtained reclaimed polyvinyl chloride from the method of the first aspect of the invention contains a remaining amount of said second thermoplastic polymer lower than 100 ppm, or even lower than 10 ppm. Preferably the level of plasticizer in said reclaimed polyvinyl choride is below 1 phr, or below 0.1 phr. Preferably, the amount of mineral filler materials in said reclaimed polyvinyl chloride is 100 phr or above. Initially, the extracting step preferably substantially maintains the filler materials in the polyvinyl chloride matrix. The availability of filler materials is beneficial in said the step of separating. Preferably, the second thermoplastic material is free from fillers, or comprises filler materials at a lower level than said first thermoplastic material, for example less than half or less than 10 percent of the weight amount contained in said first thermoplastic material.

[0012] Preferably, said second thermoplastic material is available in a polyvinyl chloride free or substantially polyvinylchloride free portion or layer of said product. This enables a higher efficiency in said separating step, and also yields a higher purity of both the reclaimed polyvinyl chloride and second thermoplastic polymer.

[0013] Preferably, said polyvinyl chloride product is sheet-shaped, wherein the bottom of said polyvinyl chloride product is formed by a textile layer formed at least from fibers formed from said second thermoplastic material. Fibers may create an additional obstacle in recycling processes as they tend to clog filters if they are insufficiently processed.

[0014] Preferably, said polyvinyl chloride product is a sheet vinyl flooring product. Preferably, said sheet vinyl flooring product comprises a textile layer at a bottom thereof, wherein the fibers of said textile layer are formed at least from polyethylene terephthalate.

[0015] Preferably, said step of separating at least comprises exerting a mechanical force, preferably a shearing action, a grinding action and / or mechanical impact, on the polyvinyl chloride product that has been subjected to solvent extraction. The risen brittleness of the polyvinyl chloride product due to the step of extracting makes a mechanical separation step more feasible and less energy intensive.

[0016] Preferably, said step of subjecting said polyvinyl chloride products to a solvent-based extraction takes place in an extraction vessel., wherein at each time at least 5kg of polyvinyl chloride products are present in said extraction vessel, and wherein said polyvinyl chloride products preferably have a surface to volume ratio of 1 : 10 or higher as expressed in 1 / mm. Preferably, said method is practiced with batch sizes of at least 5 kg of PVC products, or at least 10 kg or at least 100 kg of PVC products. Herein it is meant that said solvent and said PVC products are brought into contact with each other in an extraction vessel that at each time comprises at least 5 kg, at least 10 kg or at least 100 kg of PVC products. The method may be performed in a discontinuous manner, i.e. batch per batch, or in a continuous manner, wherein PVC product is continuously fed into said extraction vessel, and extracted material is continuously transported out of said extraction vessel.

[0017] In a preferred embodiment, the extraction vessel is filled, or at least partially filled, with polyvinyl chloride (PVC) products, after which the polyvinyl chloride (PVC) products in the extraction vessel are compacted, manually and / or mechanically. This compaction step reduces the volume that the polyvinyl chloride (PVC) products take up in the extraction vessel, such that additional polyvinyl chloride (PVC) products may be put inside the extraction vessel. This may be repeated one or more times. The inventors have found that, by performing such compaction step or steps, more polyvinyl chloride (PVC) products may be processed at once while maintaining the efficiency of the extraction process. Thanks to the compaction step or steps, the total weight of polyvinyl chloride (PVC) products in the extraction vessel may be multiplied by a compaction factor of 1.5, 2 or even 2.5, with respect to the total weight of polyvinyl chloride (PVC) products in the absence of a compaction step. Thus, such compaction steps may significantly increase the efficiency of the extraction process. Preferably, the compaction factor is less than 10, preferably less than 5 or even less than 4. This may ensure that a phenomenon known as channeling does not occur, and that the polyvinyl chloride (PVC) products may be brought into intimate contact with the solvent during the solvent-based extraction.

[0018] It is noted that it is also possible to provide a compaction of the polyvinyl chloride (PVC) products outside of the extraction vessel, after which the then compacted polyvinyl chloride (PVC) products are placed in the extraction vessel. This may also increase the efficiency of the extraction process. The inventors found, however, that it is more preferred to perform the compaction in the extraction vessel itself. Preferably said polyvinyl chloride products that are subjected to solvent-based extraction at least comprise polyvinyl chloride and a filler, for example talcum and / or calcium carbonate, such as chalk and / or limestone. Preferably said polyvinyl chloride products comprises filler at a filler to PVC weight ratio of at least 1 : 1, or of at least 3: 1.

[0019] The method of the invention, according to its first aspect, allows to efficiently recycle polyvinyl chloride products by the removal of unwanted components in a solvent-based extraction and a subsequent separation step, which components could be disadvantageous or harmful. As such, a clean PVC polymer stream may be obtained using the method of the invention.

[0020] By preference, said solvent-based extraction comprises extracting at least one component from the polyvinyl chloride (PVC) products, said component is chosen from the group of plasticizers, heavy metals, polar components, acrylic resins, organic components, pigments, additives, or combinations thereof.

[0021] Preferably, said component is a plasticizer or comprises at least a plasticizer. In light of the invention, the term “plasticizer” need to be interpreted as a substance which may be added to a material, in particular a synthetic material, with the goal of making said material softer, more flexible, to increase its plasticity, to decrease its viscosity, and / or to improve handling of said material during a manufacturing process, e.g. by decreasing friction of the material in a manufacturing line. More in particular, a distinction may be made between phthalate based plasticizers and non-phthalate based plasticizers. On one hand, phthalate based plasticizers are to be interpreted as plasticizers having a chemical structure in accordance with formula I, wherein R and R’ may be the same or may be different, and wherein R and / or R’ are chosen from the group of CnHin+i, wherein n is an integer between 1 and 15, while non-phthalate based plasticizers have a chemical structure which is not in accordance with formula I.

[0022] Extracting plasticizers upon recycling PVC products according to the method of the invention is particularly advantageous as the resulting clean PVC polymer stream may be used more efficiently for manufacturing new PVC products. More in particular, in making said new PVC products, a specific target amount of plasticizer may be easier controlled when starting from a substantially plasticizer-free PVC polymer stream.

[0023] According to some embodiments, said plasticizer is a phthalate based plasticizer in accordance with formula I. It is noted that especially those phthalate based plasticizers having a high molecular weight, such as plasticizers having a chemical structure in accordance with formula I wherein n is 5 or more, may be of high relevance in light of potential VOC emissions and the related public health concerns. More by preference, said phthalate based plasticizer is chosen from the group of diisononyl phthalate (DINP), di-(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), diisoheptyl phthalate (DIHP), di-n-octyl phthalate (DOP), diisooctyl phthalate (DIOP), diisodecyl phthalate (DIDP), or combinations thereof. The method for recycling PVC products according to the invention is particularly interesting as it allows to efficiently extract hazardous phthalate based plasticizers from the PVC products, such that new PVC products may be safely manufactured based upon the resulting clean PVC polymer stream. Furthermore, upon making new PVC products from the clean PVC polymer stream, one may specifically target the use of non-hazardous plasticizers.

[0024] According to a further or another embodiment, said component may be a non-phthalate based plasticizer not in accordance with formula I. More by preference, said non- phthalate based plasticizer is chosen from the group of benzoate esters, adipate esters, citrate esters, cyclohexanoate esters, or combinations thereof. Extraction of non- hazardous, non-phthalate based plasticizers from the PVC products allows to obtain a clean PVC polymer stream which can be more efficiently used in making new PVC products, thereby accurately controlling the composition during manufacturing of said new products.

[0025] According to some embodiments, said component may comprise a mixture of one or more phthalate based plasticizers and one or more non-phthalate plasticizers.

[0026] According to some embodiments, said component may be a heavy metal. By preference, said heavy metal is chosen from the group of antimony (Sb), arsenic (As), bismuth (Bi), cadmium (Cd), cerium (Ce), chromium (Cr), cobalt (Co), copper (Cu), gallium (Ga), gold (Au), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), nickel (Ni), platinum (Pt), silver (Ag), tellurium (Te), thallium (Tl), tin (Sn), uranium (U), vanadium (V), and zinc (Zn), or combinations thereof. More by preference, said heavy metal may be chosen from the group of copper (Cu), iron (Fe), lead (Pb), nickel (Ni), zinc (Zn), or combinations thereof.

[0027] According to some embodiments, said component may be a polar component. According to some embodiments, said component may be an acrylic resin. According to some embodiments, said component may be an organic component. According to some embodiments, said component may be a pigment, such as carbon black. According to some embodiments, said component may be an additive.

[0028] Said solvent-based extraction, according to a further or another embodiment, comprises bringing said polyvinyl chloride product into contact with at least one solvent. Said at least one solvent may herein bring the one or more components into solution, while leaving the polyvinyl chloride unaltered, thereby achieving physical separation of said one or more components from the polyvinyl chloride.

[0029] By preference, said polyvinyl chloride product is brought into contact with at least one liquid solvent. Bringing the polyvinyl chloride product into contact with a liquid solvent has the advantage that the liquid solvent may better penetrate the polyvinyl chloride product, thus making better contact with the one or more components, thereby improving solution of said one or more components into said liquid solvent.

[0030] According to some embodiments, said polyvinyl chloride product may be brought into contact with a single solvent. According to some other embodiments, said polyvinyl chloride product may be brought into contact with two or more solvents. It may herein be possible that one or more components are soluble in a first solvent, while one or more other components are soluble in a second solvent. Alternatively, said two or more solvents may bring a synergistic effect in that said one or more components may be better soluble in the presence of the combination of the two or more solvents, than in the presence of just one of said two or more solvents. According to some embodiments, said polyvinyl chloride product may be brought into contact with a solvent and an antisolvent, thereby further improving the physical separation of said one or more components from the polyvinyl chloride product. Herein, the solvent may have particular affinity towards one or more components to be extracted, while the anti-solvent has affinity with the polyvinyl chloride material. By combining these diverging affinities in a solvent / anti-solvent system, obtaining good separation between the one or more components and the polyvinyl chloride material may be easier.

[0031] According to a first preferred embodiment, said solvent comprises supercritical carbon dioxide (CO2). In light of the invention, supercritical carbon dioxide may be regarded as a liquid solvent, more in particular, it concerns a supercritical fluid state. Using supercritical carbon dioxide as a solvent may be particularly useful for the extraction of plasticizers.

[0032] Said polyvinyl chloride product is by preference brought into contact with supercritical carbon dioxide (CO2) at a temperature of between 20 and 100 °C. More by preference, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a temperature of between 50 and 95 °C. More by preference, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a temperature of between 75 and 90 °C. Even more by preference, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a temperature of between 80 and 90 °C, for example 85 °C or 88 °C. The inventors have found that such temperature is particularly advantageous for extracting components from larger batches of polyvinyl chloride products, in particular when these polyvinyl chloride products comprise filler, for example at a filler to PVC weight ratio of 1 : 1 or above, or even of 3 : 1 or above.

[0033] According to a further or another embodiment, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a pressure of between 20 and 50 MPa. By preference, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a pressure of between 30 and 50 MPa. More by preference, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide at a pressure of between 30 and 40 MPa or at a pressure between 35 and 45 MPa, for example at a pressure of 41 MPa. The inventors have found that such pressure is particularly advantageous for extracting components from larger batches of polyvinyl chloride products, in particular when these polyvinyl chloride products comprise filler, for example at a filler to PVC weight ratio of 1 : 1 or above, or even of 3 : 1 or above.

[0034] The inventors obtained good results when said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a temperature of between 50 and 95 °C and at a pressure of between 20 and 50 MPa, especially at a temperature of between 50 and 950and at a pressure of between 35 and 45 MPa. The inventors further obtained excellent results when said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a temperature of between 80 and 90 °C, in particular 85 °C or 88 °C, and at a pressure of between 35 and 45 MPa, in particular 41 MPa.

[0035] In the cases where supercritical carbon dioxide is used as a solvent, it may be used in combination with a cosolvent. The cosolvent preferably has affinity to phthalates and / or is chosen from the list consisting of water, methanol, ethyl acetate, methylene chloride. Other possibilities are cosolvents that lead to a swelling of the PVC material and / or is chosen from the list consisting of CHCh, acetone, cyclohexanone and tetrahydrofuran (THF).

[0036] According to a second preferred embodiment, said solvent comprises an ionic liquid. In light of the present invention, the term “ionic liquid” may be interpreted as liquids which consist of both organic and / or inorganic ions, and which may contain more than one cation or anion. Another way to describe “ionic liquid” may thus be “liquid salt”. Using an ionic liquid as a solvent may be particularly useful for the extraction of heavy metals. A particular kind of ionic liquids are “natural deep eutectic solvents” (NADES), which are mixtures of natural compounds, namely, organic acids and bases, amino acids, sugars, sugar alcohols, and polyalcohols that interact through hydrogen bonding and liquefy if combined in specific molar ratios.

[0037] Said polyvinyl chloride product is by preference brought into contact with the ionic liquid at a temperature of at least 100 °C. More by preference, said polyvinyl chloride product is brought into contact with the ionic liquid at a temperature of at least 150 °C.

[0038] According to a further or another embodiment, said ionic liquid may comprise one or more of l-butyl-3 -methyl imidazolium tetrafluoroborate ([BMIM][BF4]), l-butyl-3- methyl imidazolium hexafluorophosphate ([BMIM][PF6]), 2,4-bis(2-hydroxypropyl)- 1,1,3,3-tetramethyl guanidinium tetrafluoroborate ([TMGHPO2][BF4]), and tetramethyl guanidine lactate (TMGL).

[0039] According to a further or another embodiment, said ionic liquid is chosen from the group of l-octyl-3 -methyl imidazolium tetrafluoroborate ([C8mim][BF4]), l-octyl-3 -methyl imidazolium hexafluorophosphate ([C8mim][PF6]), tri ethylammonium hydrogen sulphate ([HNEt3][HSO4]).

[0040] It is clear that the cosolvents mentioned in connection to extraction with supercritical CO2 may also be used in combination with an extraction executed by means of ionic liquids in accordance with the second preferred embodiment. It is noted that solvent extraction, especially when practiced with liquid or supercritical CO2 whether or not in combination with a cosolvent, tends to extract all PVC additives that are liquid at room temperature from PVC products or PVC scrap. The obtained liquid fraction could hence comprise plasticizers, stabilizers, dispersants and other additives.

[0041] According to a particular embodiment, said solvent-based extraction is a multi-step extraction comprising the steps: (i) bringing said polyvinyl chloride product into contact with at least one ionic liquid; and (ii) bringing said polyvinyl chloride product into contact with supercritical carbon dioxide (CO2). Herein, solvent-based extraction with the ionic liquid may be advantageous for the extraction of heavy metals, and the solventbased extraction with supercritical carbon dioxide may be advantageous for the extraction of plasticizers. According to some embodiments, step (i) may be performed before step (ii). According to some other embodiments, step (i) may be performed after step (ii).

[0042] Said polyvinyl chloride product may be brought into contact with supercritical carbon dioxide (CO2) and / or the ionic liquid, according to some embodiments, during a contact time of between 2 and 90 minutes, preferably between 5 and 60 minutes. By preference said contact time is between 10 and 45 minutes. More by preference, said contact time is between 15 and 30 minutes. The inventors observed that, especially in industrial settings where large amounts of said polyvinyl chloride product are to be recycled, the machinery might have limited reaction times, thus requiring longer contact times such as between 30 and 120 minutes, or between 45 and 90 minutes.

[0043] According to some embodiments, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) and / or the ionic liquid, wherein said polyvinyl chloride has a surface to volume ratio of 1 : 10 (as expressed in 1 / mm) or higher, for example between 1 : 10 and 10:1 (as expressed in 1 / mm) or between 1 :5 and 5: 1 (as expressed in 1 / mm). It is not excluded that the surface to volume ratio would be between 1 : 1 and 1 : 10 (as expressed in 1 / mm). By preference, the polyvinyl chloride product is brought into contact with supercritical carbon dioxide and / or the ionic liquid, wherein said polyvinyl chloride product has a surface to volume ratio of between 3 : 1 and 10: 1 (as expressed in 1 / mm). According to an alternative the surface to volume ratio is between 1 :3 and 1 : 10 (as expressed in 1 / mm).

[0044] In a more particular embodiment, the polyvinyl chloride product is brought into contact with supercritical CO2 at a temperature of between 20 and 100 °C, at a pressure of between 20 and 50 MPa, during a contact time of between 5 and 60 minutes, and preferably with a surface to volume ratio of 1 : 10 (as expressed in 1 / mm) or higher, for example between 1 : 10 and 10: 1 (as expressed in 1 / mm), or between 1 :5 and 5: 1. It is not excluded to work with PVC having a surface to volume ratio between 1 : 1 and 1 : 10 (as expressed in 1 / mm). More preferably, the polyvinyl chloride product is brought into contact with supercritical CO2 at a temperature of between 50 and 95 °C, at a pressure of between 30 and 50 MPa, during a contact time of between 10 and 45 minutes, and wherein said polyvinyl chloride product preferably has a surface to volume ratio of at least 3: 1, for example between 3:1 and 10: 1. According to an alternative the surface to volume ratio is between 1 :3 and 1: 10 (as expressed in 1 / mm). Even more preferably, the polyvinyl chloride product is brought into contact with supercritical CO2 at a temperature of between 80 and 90 °C, at a pressure of between 35 and 45 MPa, during a contact time of between 10 and 45 minutes, and wherein said polyvinyl chloride product preferably has a surface to volume ratio of at least 3 : 1, for example between 3 : 1 and 10: 1. According to an alternative the surface to volume ratio is between 1 :3 and 1 : 10 (as expressed in 1 / mm).

[0045] In a preferred embodiment, the polyvinyl chloride product is brought into contact with supercritical CO2 in an extraction vessel, wherein the supercritical CO2 is preferably supplied with a flowrate or refreshing rate of between 10 and 30 kg / h, preferably between 18 and 25 kg / h, for example 20 kg / h. These flowrates or refreshing rates of supercritical CO2 are preferably related to a reaction vessel with a volume of 5 liters. These flowrates or refreshing rates provide a sufficient inflow of clean supercritical CO2 and / or sufficient outflow or saturated or partly saturated supercritical CO2, such that the extraction process may continue uninterruptedly. For extraction vessels with a different volume, the flowrate or refreshing rate may be adjusted by scaling the above mentioned values linearly with respect to the volume of the reaction vessel. In an alternative particular embodiment, the polyvinyl chloride product is brought into contact with the ionic liquid at a temperature at least 100 °C, during a contact time of between 5 and 60 minutes, and wherein said polyvinyl chloride product preferably has a surface to volume ratio of 1: 10 (as expressed in 1 / mm) or higher, for example between 1 :10 and 10: 1 (as expressed in 1 / mm), or between 1 :5 and 5:1 (as expressed in 1 / mm). It is not excluded to work with PVC having a surface to volume ratio between 1 : 1 and 1 : 10 (as expressed in 1 / mm). More preferably, the polyvinyl chloride product is brought into contact with the ionic liquid at a temperature of at least 150 °C, during a contact time of between 10 and 45 minutes, and preferably with a surface to volume ratio of at least 3: 1, for example between 3: 1 and 10: 1. According to an alternative the surface to volume ratio is between 1 :3 and 1 : 10 (as expressed in 1 / mm).

[0046] A minimal surface to volume ratio of the polyvinyl chloride products, for example at least 0.5, or at least 1, or at least 3 (as expressed in 1 / mm), is advantageous for providing a high enough surface for the respective solvent to interact with the polyvinyl chloride product and for this solvent to be efficient in extracting the respective component. The surface to volume ratio of the polyvinyl chloride products is preferably kept below a maximum value, for example below 10 (as expressed in 1 / mm) to prevent clogging of the system and / or to avoid agglomeration of the polyvinyl chloride particles. The range of surface to volume ratio between 1 :10 and 10: 1, or between 1 : 1 and 10: 1, is of particular importance to extraction at an industrial scale, namely when the batch size of PVC product is at least 5 kg, at least 10 kg or at least 100 kg, and / or, when said polyvinyl chloride products comprise filler, for example at a filler to PVC weight ratio of 1 : 1 or above, or even of 3 : 1 or above

[0047] According to a further or another embodiment, said method, prior to the step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, comprises the step of comminuting said polyvinyl chloride (PVC) products into granules, said granules having a particle size distribution percentile D90 value of at most 6 mm, preferably at most 4 mm, more preferably less than 2,5 mm and / or a D50 percentile value or less than 1,75 mm. The inventors obtained excellent results in terms of extraction efficiency for granules having a particle size distribution percentile D90 value of 4 mm, especially when the polyvinyl chloride products are brought into contact with supercritical CO2 at a temperature of between 80 and 90 °C such as 85 °C or 88 °C, at a pressure of between 35 and 45 MPa such as 41 MPa. Furthermore, it is observed that the previously described compaction step was found to provide excellent results for granules having a particle size distribution percentile D90 value of at most 6 mm, such as 4 mm or 2.5 mm.

[0048] In general it is remarked that, wherever particle size percentile D90 or D50 values are described herein, the particle size may be measured by various techniques known in the art. Particularly for larger granules, the particle size may possibly be determined by sieving techniques. The particle size of smaller particles may be determined by laser granulometry, in particular, the particle size percentile D90 or D50 may be determined using laser granulometry, which may be performed in accordance with ISO 13320:2020. This is a dynamic light scattering technique using a laser with an emission wavelength of 632.8 nm, measuring at a scattering angle of 90 degrees. This technique may be performed, for example, with a Malvern® Mastersizer 2000 or with a Malvern® Mastersizer 3000. To perform the measurement of the particle size distribution, the respective particles need to be brought in a loose state, and can be dispersed in a liquid, such as water.

[0049] It is further remarked that the surface to volume ratio of the polyvinyl chloride products may be determined as being equal to 6 / D50 and expressed in 1 / mm, with the D50 percentile of the particle size distribution being determined as explained above.

[0050] According to some preferred embodiments, said polyvinyl chloride (PVC) products are comminuted into granules having a particle size distribution with a D90 percentile value of less than 2 mm, more by preference of less than 1,5 mm, of less than 1 mm, most by preference of less than 0,5 mm.

[0051] According to some embodiments, the solvent-based extraction may be brought about in multiple steps. In particular, said polyvinylchloride (PVC) products may first be comminuted into granules having a first particle size, for example a particle size D90 value of less than 2 mm, and may subsequently be subjected to a first solvent-based extraction step. Thereafter, the products may be comminuted into granules having a second particle size which is smaller than the first particle size, for example a particle size D90 of less than 0,5 mm, and may subsequently be subjected to a second solventbased extraction step. As PVC material with a low amount of plasticizers is generally more brittle, it may be easier to comminute said material into small granules. Hence, a multi-step process as described herein may have the advantage that plasticizer content is gradually lowered, thereby allowing comminuting the PVC into still smaller granules. In its turn, subjecting small granules to solvent-based extraction may allow improved extraction altogether. It may be possible that two consecutive steps are performed, or that even three or more consecutive steps are performed. The used solvents in each of the steps may be the same, or may be different. For example, supercritical carbon dioxide extraction may be performed in a first step on larger particle sizes, while ionic liquid extraction may be performed in the second step on still smaller particles.

[0052] Said method, prior to the step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction or, if present, prior to the step of comminuting said polyvinyl chloride (PVC) products into granules, may according to some embodiments also comprise the step of mechanically separating non-polyvinyl chloride (non-PVC) material from polyvinyl chloride (PVC) material. As PVC products may also comprise a lot of non-PVC material, this may render recycling said PVC products more difficult. By separating said non-polyvinyl chloride material from said polyvinyl chloride material, the recycling thereof may thus be improved. Examples of non-PVC material include polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), or polyurethane (PU). In particular where the PVC products concern floor or wall coverings, said non-PVC material may for example include a non-PVC backing layer, a non-PVC top layer, a non-PVC pad-attached, or combinations thereof. It is clear that, in accordance with the first aspect of the invention, non-PVC material, namely said second thermoplastic polymer, is subjected to said step of extracting. Said second thermoplastic polymer may be a portion of said non-PVC backing layer which has not been removed in said preceding step of mechanically separating. In a preferred embodiment, said step of mechanically separating comprises separating by melt filtration, by tribocharging and / or by windsifting. Each of these possibilities may be used alone or in combination, in any chosen order, providing excellent results in terms of mechanical separation between PVC material and non-PVC material, for example PET fibers. In a preferred embodiment, the step of mechanically separating comprises separating by tribocharging followed by separating by melt filtration. The inventors found that, by first performing separation by tribocharging, that a sufficiently high degree of purity may be obtained, which provides an excellent starting material for the subsequent melt filtration. As such, very high degrees of purity may be obtained. In another preferred embodiment, the step of mechanically separating comprises separating by windsifting followed by separating by melt filtration. The inventors found that, by first performing separation by windsifting, that a sufficiently high degree of purity may be obtained, which provides an excellent starting material for the subsequent melt filtration. As such, very high degrees of purity may be obtained.

[0053] In a very preferred embodiment, prior to the step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, the polyvinyl chloride products may be comminuted, followed by a step of mechanically separating. This step of mechanically separating preferably relates to windsifting and / or melt filtration. In some embodiments, after the step of mechanically separating by windsifting, and preferably before melt filtration, the polyvinyl chloride products are subjected to a step of micronizing. Preferably, after the step of micronizing, the polyvinyl chloride products have a particle size distribution percentile D90 value between 1 and 1000 micrometer, preferably between 50 and 800 micrometer, more preferably between 200 and 600 micrometer, for example 400 or 500 micrometer. The inventors observed that this step of micronizing may further loosen non-PVC products such as fibers, e.g. PET fibers, which provides an even better starting material for the melt filtration.

[0054] In a preferred embodiment, after the step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, the polyvinyl chloride (PVC) products are subjected to one or more of micronizing, windsifting, tribocharging and melt filtration. Preferably, these polyvinyl chloride (PVC) products are subjected to micronizing, windsifting and melt filtration, preferably in this order.

[0055] It is noted that, according to a variant of the first independent aspect, the method does not comprise the step of subjecting polyvinyl chloride (PVC) products to a solvent-based extraction. In this case, preferred embodiments of the first independent aspect may equally be applied to this variant as long as this does not lead to contradictions. This variant may reduce the complexity of and required investments for the recycling process, however, may result in longer processing times and energy consumption.

[0056] Additionally or alternatively, prior to the step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction or, if present, prior to the step of comminuting said polyvinyl chloride (PVC) products into granules, said method may according to some embodiments also comprise the step of mechanically separating polyvinyl chloride (PVC) material which comprises contaminants from polyvinyl chloride (PVC) material which does not comprise contaminants. For example, PVC material comprising heavy metals may be mechanically separated from PVC material not comprising heavy metals. According to some embodiments, said mechanical separation may be performed by means of infrared (IR) techniques.

[0057] According to some embodiments, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, may also comprise the step of washing said post-extraction polyvinyl chloride (PVC) products before, after and / or during said step of separating the first polymer from the second polymer.

[0058] According to a further or another embodiment, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, may comprise the step of purifying said at least one component that has been extracted. Obtaining a higher purity of the extracted component may allow subsequent processing or reuse of said component. According to a further or another embodiment, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, thereby extracting at least said plasticizers, may comprise the step of separating non-phthalate plasticizers from phthalate plasticizers.

[0059] Said step of purifying and / or said preceding step of separating may be performed by using one or more pressurized and potentially heated tanks. In such tank the liquid fraction of the extracted material or part thereof may be tapped off. Depending on the pressure and temperature conditions in such tank, different components may be available in the tapped off liquid fraction. The extracted material may subsequently be passed through several tanks operating at mutually different temperature and pressure conditions, and at one or more of these tanks the obtained liquid fraction may be tapped off. The different temperature and pressure conditions may lead to liquid fractions having different compositions.

[0060] According to the most preferred embodiment, said step of solvent-based extraction is performed by mixing CO2, preferably supercritical CO2, and potentially a cosolvent, e.g methanol or another cosolvent mentioned in connection to the first aspect of the invention, with PVC granulate obtained from scrap PVC material in a first vessel, the so- called extractor vessel. The extracted material is transported from the extractor vessel by a plurality of subsequent separator vessels operating at least at different pressures and potentially at different temperature. At at least one, and preferably at each of said separator vessels a respective liquid fraction is removed. The removal may happen at a time when the pressure is released from the respective vessel. This embodiment may conveniently lead to a separation of mutually different fractions as a part of the extraction process, preferably each having a different main component.

[0061] According to a further or another embodiment, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, may comprise the step of converting phthalate plasticizers to non-phthalate plasticizers, preferably by means of a transesterification and / or hydrogenation reaction. For example, diisononyl phthalate (DINP) may be converted to 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH). In each case, substances which may be considered to be harmful may be converted into substances which are considered at least less harmful, to even unharmful with respect to current regulations.

[0062] According to some embodiments, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, and preferably after said step of separating said first polymer from said second polymer, comprises the step of supplementing said post-extraction polyvinyl chloride (PVC) products with virgin polyvinyl chloride (PVC), plasticizers, compatibilizers, or combinations thereof. This may be particularly useful in that reactivity and / or quality of the post-extraction PVC may be improved, such that it may be more suitable for manufacturing new PVC products.

[0063] According to a preferred embodiment, said polyvinyl chloride (PVC) products are floor or wall coverings, preferably floor or wall panels. Preferably said polyvinyl chloride (PVC) products are composed of a plurality of layers, wherein a majority of said layers are preferably comprising PVC and one or more of said components. Two or more of the composing layers of such product may have a mutually different composition, for example a mutually different filler content and / or plasticizer content. For example, said polyvinyl chloride (PVC) products may comprise a substrate of a filled PVC (for example calcium carbonate to PVC weight ratio of at least 3: 1), which for example comprises 5 phr or less of plasticizer, an applied thereon printed PVC film, which for example also comprises 5 phr of plasticizer or less but is free or essentially free from fillers, and a PVC wear layer applied to said printed PVC film, which for example comprises 15 phr or more of plasticizer and is essentially free of fillers. The thickness of the composing layers may be substantially different. For example, the substrate may be 1 to 5 mm thick, while the printed PVC film has a thickness of 50 to 100 micron, and the PVC wear layer has a thickness of 0.2 to 1 mm. The inventors have discovered that a method of extraction using one or more solvents as described herein is particularly advantageous for the treatment of waste having such non-uniform composition. In particular the use of supercritical CO2 and / or an ionic liquid as solvent, preferably in combination with a co-solvent has proven to provide a very versatile extraction method in these cases. Also the surface to volume ratio above 1 : 10 or above 1 : 1 is of interest in such case, since it may expose all composing layers to a satisfactory extent.

[0064] Said polyvinyl chloride (PVC) products may comprise, according to some embodiments, PVC in an amount of between 20 and 100 wt.%. More by preference, polyvinyl chloride may be present in an amount of between 20 and 40 wt.%.

[0065] In some embodiments, said polyvinyl chloride (PVC) products may also comprise filler, preferably mineral filler, in an amount of between 0 and 80 wt.%. More by preference, filler may be present in an amount of between 60 and 80 wt.%.

[0066] According to some embodiments, said polyvinyl chloride (PVC) products comprise plasticizers, preferably phthalate-based plasticizers, in an amount of between 1 and 50 phr, more preferably between 10 and 25 phr.

[0067] According to some embodiments, the solvent-based extraction may be performed in a reactor. Alternatively or additionally, the solvent-based extraction may be performed in an extruder.

[0068] Additionally or alternatively, said solvent may comprise water and / or an additional extraction step using water as a solvent may be implemented in the method according to the invention.

[0069] Additionally or alternatively, the method may also comprise a complexation step, wherein the polyvinyl chloride (PVC) products are brought into contact with one or more complexing agents, such as ethylene diamine tetra-acetic acid (EDTA). The use of EDTA may be particularly beneficial for the extraction of heavy metals. Bringing the polyvinyl chloride (PVC) products into contact with one or more complexing agents, may be performed in an extruder. Alternatively, said step may be performed in a reactor.

[0070] Additionally, use may be made of a melt filtration step subsequent to said step of separating said second polymer from said polyvinyl chloride. It is noted that some embodiments as mentioned above may also enhance an extraction process where said polyvinyl chloride (PVC) products are free from a second thermoplastic polymer other than polyvinyl chloride. It is thus clear that the invention also, independently, concerns a method for the extraction of such PVC products. In such case, there is no need for separating at least partially said second thermoplastic polymer from said first thermoplastic polymer. Preferred embodiments of the first independent aspect may thus also form preferred embodiments of this independent invention, as long as this does not lead to contradictions. For example, the one or more compaction steps and / or the step of mechanically separating and / or the step of comminuting may provide additional efficiency to a process wherein such PVC products are extracted or recycled, as well.

[0071] With the same aim as in the first independent aspect, the present invention, in accordance with a second independent aspect pertains to a method for manufacturing polyvinyl chloride (PVC) products, comprising the step of providing polyvinyl chloride (PVC) material, wherein said polyvinyl chloride (PVC) material is obtained by a method according to the first aspect of the invention.

[0072] Said polyvinyl chloride (PVC) product may be a floor or wall panel. According to the most preferred embodiment, said polyvinyl chloride (PVC) product is a sheet flooring product, for example a so-called cushion vinyl. The second thermoplastic material may at least be available as a textile layer at the bottom of the sheet flooring product. Cushion vinyl is a multilayered flooring product, and may be built up starting from a liner having a foamed PVC layer applied thereto, i.e. the actual cushion vinyl layer. Said foamed layer may comprise two or more sublayers, and is usually obtained from applying PVC plastisol to said liner, and subsequently foaming the plastisol. On top of the foamed layer a printed decor is positioned. The printed decor may be applied as a prefabricated and preprinted foil, such as a printed PVC foil, or it may be formed directly on the foamed layer, e.g. with the intermediary of suitable primers and other base layers, such as layers on the basis of PVC plastisol. A transparent layer is applied on top of said printed decor in order to protect from abrasion and other wear. The transparent layer may also be based on PVC. Possibly, at the surface of said transparent layer a superficial lacquer layer may be present, such as an acrylate-, urethane acrylate- or polyurethane based lacquer layer.

[0073] According to some embodiments, said method comprises the steps of forming a substrate on the basis of said polyvinyl chloride (PVC) material, providing a decorative layer onto an upper surface of said substrate, and providing a wear layer onto an upper surface of said decorative layer. Forming a substrate on the basis of said polyvinyl chloride (PVC) material may be performed by means of an extrusion operation, a scattering operation, or an operation including gelling of a plastisol.

[0074] According to some embodiments, the substrate may be single-layered or comprising a plurality of substrate layers, preferably an uneven number of substrate layers. The substrate, whether single-layered or multi-layered, preferably forms at least half the thickness and / or half the weight of said panel and / or is at least available at a central location within the thickness of said panel. According to some embodiments, the decorative layer is a thermoplastic decorative layer. Preferably, said thermoplastic decorative layer is a thermoplastic decorative film, said thermoplastic decorative layer comprising a print. According to some embodiments, the wear layer is a transparent and / or translucent thermoplastic wear layer. Preferably, said transparent and / or translucent thermoplastic wear layer is a thermoplastic film. According to some embodiments, a lacquer layer is present onto an upper surface of said wear layer.

[0075] The floor or wall panel of the invention preferably has a total thickness between 2 and 8 mm, and even better between 3 and 6 mm. The substrate, whether multi-layered or single layered, preferably has a thickness between 2 mm and 5 mm. In the case of a sheet flooring product, that too may have a total thickness between 2 and 5 mm.

[0076] The floor or wall panel of the invention may be provided on at least two opposite edges with coupling parts, allowing that two such panels at the respective edges can be coupled to each other, wherein, in the coupled condition, a locking is obtained in a vertical direction perpendicular to the plane of coupled panels, and in a horizontal direction in the plane of coupled panels and perpendicular to said edges. According to a preferred embodiment of said first independent aspect, said method for recycling comprises: providing industrial, post-industrial and / or post-consumer flexible PVC products, i.e. products comprising PVC and plasticizer, preferably at a rate of 5 phr or more, such as cushion vinyl flooring products or floor panels comprising soft PVC, such as LVT, wherein these products comprise a textile layer at a bottom side thereof, and wherein the textile layer is made from fibers obtained from a second thermoplastic polymer different from PVC, e.g. polyethylene terephthalate or polypropylene; subjecting said PVC products to a solvent-based extraction, preferably at least using supercritical and / or liquid CO2 to thereby extract from said PVC product a liquid fraction comprising at least said plasticizer; and subjecting the thus extracted PVC products to said step of separating, e.g. with a milling or grinding operation, to thereby separate the second thermoplastic polymer from said PVC.

[0077] With the same aim as in the first and second independent aspect, the present invention, in accordance with a third independent aspect pertains to a polyvinyl chloride (PVC) product comprising polyvinyl chloride (PVC) material and one or more components chosen from the group of plasticizers, heavy metals, polar components, acrylic resins, organic components, pigments, additives, or combinations thereof, and / or wherein said polyvinyl chloride (PVC) material is obtained by a method according to the first aspect of the invention and / or wherein said polyvinyl chloride (PVC) product is obtained by a method according to the second aspect of the invention.

[0078] By preference, said one or more components have a concentration of below 1000 ppm, preferably of below 100 ppm.

[0079] By preference, said polyvinyl chloride (PVC) product is a floor or wall panel. According to some embodiments, said polyvinyl chloride (PVC) product comprises a substrate on the basis of said polyvinyl chloride (PVC) material, a decorative layer provided onto an upper surface of said substrate, and a wear layer provided onto an upper surface of said decorative layer.

[0080] According to some embodiments, the substrate may be single-layered or comprise a plurality of substrate layers, preferably an uneven number of substrate layers. The substrate, whether single-layered or multi-layered, preferably forms at least half the thickness and / or half the weight of said panel and / or is at least available at a central location within the thickness of said panel. According to some embodiments, the decorative layer is a thermoplastic decorative layer. Preferably, said thermoplastic decorative layer is a thermoplastic decorative film, said thermoplastic decorative layer comprising a print. According to some embodiments, the wear layer is a transparent and / or translucent thermoplastic wear layer. Preferably, said transparent and / or translucent thermoplastic wear layer is a thermoplastic film. According to some embodiments, a lacquer layer is present onto an upper surface of said wear layer.

[0081] The floor or wall panel of the invention preferably has a total thickness between 2 and 8 mm, and even better between 3 and 6 mm. The substrate, whether multi-layered or single layered, preferably has a thickness between 2 mm and 5 mm.

[0082] The floor or wall panel of the invention may be provided on at least two opposite edges with coupling parts, allowing that two such panels at the respective edges can be coupled to each other, wherein, in the coupled condition, a locking is obtained in a vertical direction perpendicular to the plane of coupled panels, and in a horizontal direction in the plane of coupled panels and perpendicular to said edges.

[0083] In view of all aspects, it is noted that the polyvinyl chloride (PVC) product, whether this concerns a product to be recycled by means of a method according to the first aspect of the invention, whether this concerns a product according to the third aspect of the invention, and / or whether this concerns a product to be manufactured by means of a method according to the second aspect of the invention, is not limited to floor or wall panels. Other polyvinyl chloride (PVC) products may be suitable and / or relevant as well in light of the present invention, such as PVC toys, PVC door profiles, PVC window profiles, PVC containers, and the like.

[0084] It is noted that some PVC products may comprise high amounts of fillers, such as up to 80 wt% of calcium carbonate. Thus, calcium carbonate may to a large extent contribute to the environmental impact of the entire PVC product. With the aim of providing alternative PVC products that, in accordance with preferred embodiments may still further limit the environmental impact of PVC products, the present invention, in accordance with a fourth independent aspect thereof, is a floor or wall covering or a floor or wall panel comprising a substrate and a top layer provided on said substrate, wherein said substrate comprises calcium carbonate, with as a characteristic that at least a portion of said calcium carbonate is of a biological and / or a waste origin and / or is obtained by carbonatation of calcium oxide, wherein said substrate further comprises a moisture neutralizing agent. These sources of calcium carbonate offer a high potential of limiting the environmental impact of such floor or wall products. It is clear that the floor or wall products of the present fourth independent aspect may be obtained through a method showing the characteristics of the first and / or second aspect and / or the first particular independent aspect of the present invention and / or the preferred embodiments thereof. For example such products may contain PVC obtained through a method of recycling in accordance with the first independent aspect of the present invention. The inventors have however found that calcium carbonate obtained from such sources may be hygroscopic or have a relatively high humidity. The available moisture may lead to defects in the obtained floor or wall covering or floor wall panel. The inventors have in particular found problems with formation of blisters and bubbles in the PVC substrate, and they managed to mitigate or minimize the risk of defects occurring by using moisture neutralizing agents, preferably in that portion of the substrate that contains the calcium carbonate from biological and / or a waste origin and / or obtained by carbonatation of calcium oxide.

[0085] In a preferred embodiment, the amount of calcium carbonate of biological and / or waste origin and / or is obtained by carbonatation of calcium oxide is between 0 and 95% of the total amount of calcium carbonate in the floor or wall covering or floor or wall panel, preferably between 20 and 90%, more preferably between 30 and 80%, even more preferably between 40 and 60%. This may improve the circularity and sustainability of the floor or wall covering or floor or wall panel.

[0086] Preferably, said calcium carbonate is at least obtained from egg shells. Alternatively, said calcium carbonate may be at least obtained from snail shells or seafood shells, such as the shells from mussels, oysters, scallops and / or clams. Further alternatively, said calcium carbonate may be at least obtained from cuttlefish bones, and / or from coral skeletons such as for example from coral polyps, and / or from crustacean exoskeletons such as from crabs, lobsters and / or shrimps, and / or from the skeleton of echinoderms such as sea urchins and or starfishes. It is noted that said calcium carbonate may be obtained from any combination of the aforementioned possible sources, however preferably at least egg shells. Calcium carbonate obtained from these sources, especially from egg shells, may have a platelet shape that results in an increased dimensional stability of the floor or wall covering or panel. It is especially calcium carbonate obtained from these sources that may lead to defects such as blister or bubble formation. Further alternatively, said calcium carbonate is at least obtained from paper waste or is at least obtained as waste minerals from the exploitation of shale gas.

[0087] According to a special embodiment said calcium carbonate is at least obtained by carbonatation of calcium oxide. Carbonatation of calcium oxide may lead to calcium carbonate particles that have a better defined particle size and shape. The resulting mechanical properties, such as the bending strength, as well as the dimensional stability of a floor or wall covering or panel that is filled with such material may be better predictable. This is also the case when the origin of the calcium oxide is not from waste or biological. Preferably, however the carbon dioxide needed for the carbonatation process may be recuperated from exhaust gasses, for example of power plants. By doing so, a negative carbon foot print may be obtained.

[0088] According to still another embodiment, said calcium carbonate is at least obtained from quarry waste, for example from marble quarries, or from building scrap and waste. According to a preferred embodiment, the calcium carbonate of biological and / or waste origin and / or is obtained by carbonatation of calcium oxide has a particle size distribution with a D98 value of 250 pm or less, preferably of 150 pm or less, more preferably of 100 pm or less.

[0089] Here below some practical embodiments for a moisture neutralizing agent are described.

[0090] According to a first practical embodiment the moisture neutralizing agent is or comprises porous particles and / or aluminum silicate particles and / or silica particles and / or particles having a BET specific surface area, as measured in accordance with ISO 9288:2022, of 5 to 500 m2 / g, preferably 50 to 350 m2 / g or 125 to 250 m2 / g. Such particles may absorb or neutralize moisture due to the typical availability of internal channels in these particles. In the case of aluminum silicate particles this may concern particles of hydrated aluminosilicate or so-called Zeolite (e.g. EC number 930-915-9 or CAS number 1318- 02-1). Hydrated aluminosilicate particles may have a specific surface area in the above ranges. In the case of silica particles this may concern fumed silica or precipitated silica or silica gel. Fumed silica is preferred for its larger specific surface area; precipitated silica may be preferred from an economic viewpoint.

[0091] According to a second practical embodiment the moisture neutralizing agent is or comprises an agent that reacts or binds to water. For example the moisture neutralizing agent may be or may comprise calcium oxide. In contact with water calcium hydroxide will be formed and a portion of the moisture may be neutralized by means of this chemical reaction.

[0092] Preferably, 0.1 to 10 parts or 0,5 to 5 parts, more preferably 1.0 to 3.5 parts or even 1.5 to 3.0 parts of said moisture neutralizing agent are used per 100 parts of calcium carbonate from biological, waste or carbonatation origin.

[0093] It is noted that the use of a moisture neutralizing agent may also be of interest when the filler material is different from calcium carbonate. Preferably the filler material is however mineral. Therefor in accordance with a further particular independent aspect, the present invention is a floor or wall covering or a floor or wall panel comprising a substrate and a top layer provided on said substrate, wherein said substrate comprises a filler material, with as a characteristic that said substrate further comprises a moisture neutralizing agent. Of course the moisture neutralizing agents as described in the context of the fourth independent aspect may be used here, whether or not in the ranges that were described in that context.

[0094] With the same aim as in the fourth aspect, the present invention in accordance with its fifth independent aspect is a method of manufacturing floor or wall coverings or floor or wall panels, wherein said method at least comprises the following steps:

[0095] - the step of providing a mineral filler, e.g. calcium carbonate;

[0096] - the step of providing a substrate material comprising said mineral filler, e.g. said calcium carbonate and a moisture neutralizing agent; with as a characteristic that said mineral filler, for example calcium carbonate, is of a biological and / or a waste origin and / or is obtained by carbonatation of calcium oxide. It is clear that the moisture neutralizing agents mentioned in the third aspect may be practiced in this fourth aspect, preferably in the same or similar ranges.

[0097] It is clear that the method of the fifth aspect may be practiced to obtain the coverings or panels of the fourth aspect and / or preferred embodiments thereof. This means that preferred embodiments of coverings or panels of said fourth aspect lead to corresponding preferred embodiments of the method of the present fifth aspect.

[0098] Preferably, said mineral filler is provided as calcium carbonate obtained at least from egg shells. The calcium carbonate may be obtained by grinding egg shells and removing the egg membrane. The egg membrane contains collagen which may be valorized in higher end applications. According to an alternative, calcium carbonate is provided at least by obtaining it from snail shells or seafood shells, preferably at least by grinding said shells. Similarly, for the case where one or more types of crustacean exoskeleton or the skeleton of echinoderms are used, the calcium carbonate may be provided by at least grinding said exoskeletons and / or skeletons. The calcium carbonate, in particular that which is obtained from egg shells may have a platelet shape. According to still a further alternative said calcium carbonate is provided at least by obtaining it from paper waste or from waste minerals from the exploitation of shale gas, for example from the waste water produced in shale gas fracturing.

[0099] According to a special preferred embodiment, said mineral filler is provided as calcium carbonate obtained at least by carbonatation of calcium oxide. Said calcium oxide may be suspended in water during the carbonatation process, and preferably functionalized. Such process may lead to a well-controlled size and shape of the obtained calcium carbonate particles. For example platelet shaped particles may be obtained. Preferably, the carbon dioxide needed in the carbonatation process is obtained from exhaust gasses, for example of power plants.

[0100] The substrate of the coverings or panels of the fourth and fifth aspect is preferably a filled synthetic material, wherein the filler material comprises said calcium carbonate. The synthetic material may be a thermoplastic material chosen from the list consisting of polyvinyl chloride, polyethylene terephthalate, polypropylene, polyethylene and polyurethane. Preferably, at least 50 wt% of said filled synthetic material is said filler material.

[0101] In general, said calcium carbonate preferably has a platelet shape.

[0102] It is remarked that in combination with using a moisture neutralizing agent as in the fourth or fifth aspect, or as an alternative to using a moisture neutralizing agent, the mineral filler, may be subjected to a drying treatment to bring its residual moisture content to below 1%, or below 0.5 %. Such method is a further independent aspect of the present invention which may be defined as a method for manufacturing floor or wall coverings or floor or wall panels, wherein said method at least comprises the following steps:

[0103] - the step of providing a mineral filler, e.g. calcium carbonate;

[0104] - the step of providing a substrate material comprising said mineral filler, e.g. said calcium carbonate; with as a characteristic that said step of providing said mineral filler comprises a drying treatment wherein the residual moisture content of said filler is brought to 1% or below, preferably to 0,5% or below. Preferably said mineral filler comprises calcium carbonate of a biological and / or a waste origin and / or is obtained by carbonatation of calcium oxide.

[0105] It is clear that preferred embodiments of coverings or panels of said fourth aspect lead to corresponding preferred embodiments of the method of the present aspect without there necessarily being a moisture neutralizing agent.

[0106] The substrate of the floor or wall coverings or floor or wall panels of the third and fourth aspects preferably comprise a plurality of layers, wherein at least a first layer comprises said calcium carbonate from biological, waste and / or carbonatation origin, and at least a second layer comprises no or less such calcium carbonate. Preferably said first layer is distanced from the top layer at least by said second layer. By having the particular calcium carbonate in a layer remote from the top layer, potential defects or color differences caused by this filler may be less disturbing. In such case, the use of moisture neutralizing agents may even be dispensed with. It is thus clear that the invention in accordance with a further independent aspect also is a floor or wall covering or a floor or wall panel comprising a substrate and a top layer provided on said substrate, wherein said substrate comprises at least a first layer and a second layer, wherein said first layer comprises mineral filler material from a biological and / or waste origin and / or is obtained by carbonatation of calcium oxide, and said second layer is free from such mineral filler material or comprises such mineral filler material in a lesser amount, for example less than half the weight amount, wherein said first layer is distanced from said top layer at least by said second layer. The inventors found that said mineral filler material from a biological and / or waste origin and / or is obtained by carbonatation of calcium oxide may have a yellow or orange color or shine, which may not be desired as it may disrupt a possible decorative appearance of the floor or wall covering or floor or wall panel. Thanks to this further independent aspect, this effect may be reduced, thus safeguarding possible decorative appearances at the top layer, while still providing benefits in terms of circularity and sustainability. It is clear that both said first and second layer may comprise polyvinyl chloride, wherein also said second layer may be filled with a mineral filler material, albeit preferably with a virgin mineral filler material. It is further clear that the mineral filler materials from biological origin, waste origin, carbonatation origin may be those listed in the context of the third independent aspect of the present invention, without necessarily applying a moisture neutralizing agent.

[0107] In a preferred embodiment, the top layer comprises at least a print layer and one or more decorative ink layers applied thereon at the side opposite from the substrate, wherein the print layer, and preferably every layer of the top layer, is free or essentially free from mineral filler material from a biological and / or waste origin and / or is obtained by carbonatation of calcium oxide. This may ensure that the appearance of the decor formed by the decorative ink layers is not altered by a possible yellow or orange shine of this kind of mineral filler material.

[0108] With the intention of better showing the characteristics according to the invention, in the following, as an example without limitative character, several embodiments are described, with reference to the accompanying drawings, wherein

[0109] - Figure 1 illustrates some steps in a method for recycling PVC products in accordance with amongst others the first aspect of the invention;

[0110] - Figure 2 illustrates some steps in a method for manufacturing a PVC products in accordance with amongst others the first particular independent aspect of the invention;

[0111] - Figure 3 illustrates a top view in accordance with the arrow F3 on figure 2; and

[0112] - Figure 4 shows a cross-section in accordance with the line IV-IV on figure 3.

[0113] Figure 1 illustrates a method for recycling PVC products 1, wherein the method comprises the step SI of subjecting said PVC products to a solvent-based extraction.

[0114] In the represented case post-industrial and / or post-consumer flexible PVC products 1 comprising plasticizer at a rate of 5 phr or more are comminuted into granules 2 and providing the granules 2 in an extraction vessel 3. Said step SI of solvent-based extraction is performed by mixing supercritical CO2 and a cosolvent, e.g. methanol with the granules 2. In this case, the post-consumer flexible PVC products 1 comprise sheet vinyl flooring having a textile layer or backing 21 of a second thermoplastic polymer, more particularly polyethylene terephthalate at the bottom thereof. The extracted material is transported from the extractor vessel 3 to one or more separator vessels 4, in this case only one extractor vessel 4 is represented. At the extractor vessel 4 a base liquid fraction 5 may be removed, which may or may not be further subjected to purification before being reused in a PVC product, e.g. a sheet vinyl flooring 6.

[0115] The thus extracted PVC granules 2A may be milled to yield a base PVC powder fraction 7 at the outlet of the extractor vessel 3. In accordance with the first aspect, the PVC granules 2A or the base PVC powder 7 is subjected to a step of separating the second thermoplastic polymer for the PVC. Such is not explicitly illustrated here. After said step of separating the obtained reclaimed PVC powder may be reused in a PVC product, such as in a sheet vinyl flooring 6.

[0116] The thus obtained base liquid fraction 5 may be formed for at least 75 wt% of plasticizers and can be used without further purification as plasticizer in a PVC plastisol 8. The base PVC powder fraction 7 may have a particle size distribution with a D90 value of 500pm or less, and can be added without further separation or sieving to a PVC plastisol 8.

[0117] Figure 2 illustrates the use of such a plastisol 8 for the manufacturing of a sheet vinyl flooring 6. Hereto a liner 9, for example a woven glass fiber layer is provided with said plastisol 8 by means of a doctor blade 10 on a roll 11, and then gelled in an oven 12. In the example, the coating and gelling is repeated. Subsequently a printed pattern 13 is provided, in this case by means of roller printing 14, and a transparent layer 15 is applied on top of said printed pattern 13. In the example, an embossing step S2, using an embossing roller 16, is performed to create excavations 17 at least in said transparent layer 15. Downstream of the embossing roller 16 a roller application of a top coating is shown.

[0118] Figure 3 in a top view clearly shows that the printed pattern 13 represents multiple adjacent rows 18 of wooden panels. From figure 4 it can be gleaned that the adjacent rows 18 are separated by means of a groove 19, in this case a V-shaped groove. In the example the layer 20 provided by the plastisol 8 has been foamed, and the product of figure 4 is hence an example of a cushion vinyl sheet flooring 6A.

[0119] On the bottom of the cushion vinyl sheet flooring 6A, in this case, a textile backing 21 has been provided. Such textile backing 21 provides for additional walking comfort. Preferably such textile backing 21 is a non-woven textile of polypropylene filaments. Alternatively the textile backing 21 may be a non-woven textile of PVC or polyethylene terephthalate.

[0120] The present invention also relates to methods and products as defined by the following numbered paragraphs:

[0121] 1.- Method for recycling polyvinyl chloride (PVC) products, preferably polyvinyl chloride (PVC) floor or wall coverings, characterized in that, said method comprises the step SI of subjecting said polyvinyl chloride (PVC) products 1 to a solvent-based extraction.

[0122] 2.- Method according to numbered paragraph 1, characterized in that, said solvent-based extraction comprises extracting at least one component from the polyvinyl chloride (PVC) products, said component is chosen from the group of plasticizers, heavy metals, polar components, acrylic resins, organic components, pigments, additives, or combinations thereof.

[0123] 3.- Method according to numbered paragraph 2, characterized in that, said component is a plasticizer, preferably a phthalate-based plasticizer in accordance with formula I, wherein R and R’ may be the same or may be different, and wherein R and / or R’ are chosen from the group of CnFbn+i, wherein n is an integer between 1 and 15, more preferably chosen from the group of diisononyl phthalate (DINP), di-(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), diisoheptyl phthalate (DIHP), di-n-octyl phthalate (DOP), diisooctyl phthalate (DIOP), diisodecyl phthalate (DIDP), or combinations thereof.

[0124] 4.- Method according to any of the preceding numbered paragraphs, characterized in that, said solvent-based extraction comprises bringing said polyvinyl chloride product 1 into contact with at least one solvent, preferably at least one liquid solvent.

[0125] 5.- Method according to any of the preceding numbered paragraphs, characterized in that, said solvent comprises supercritical carbon dioxide (CO2).

[0126] 6.- Method according to numbered paragraph 5, characterized in that, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a temperature of between 20 and 100 °C, preferably of between 50 and 95 °C, more preferably of between 75 and 90 °C.

[0127] 7.- Method according to numbered paragraph 5 or 6, characterized in that, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a pressure of between 20 and 50 MPa, preferably of between 30 and 50 MPa.

[0128] 8.- Method according to any of the preceding numbered paragraphs, characterized in that, said solvent comprises an ionic liquid.

[0129] 9.- Method according to numbered paragraph 8, characterized in that, said polyvinyl chloride product is brought into contact with the ionic liquid at a temperature of at least 100 °C, preferably of at least 150 °C.

[0130] 10. Method according to numbered paragraph 8 or 9, characterized in that, said ionic liquid comprises one or more of l-butyl-3 -methyl imidazolium tetrafluoroborate ([BMIM][BF4]), 1 -butyl -3 -methyl imidazolium hexafluorophosphate ([BMIM][PF6]), 2,4-bis(2-hydroxypropyl)-l, 1,3,3-tetramethyl guanidinium tetrafluoroborate

[0131] ([TMGHP02] [BF4]), and tetramethyl guanidine lactate (TMGL).

[0132] 11.- Method according to any of numbered paragraphs 8 to 10, characterized in that, said ionic liquid is chosen from the group of l-octyl-3 -methyl imidazolium tetrafluoroborate ([C8mim][BF4]), l-octyl-3 -methyl imidazolium hexafluorophosphate ([C8mim][PF6]), triethylammonium hydrogen sulphate ([HNEt3][HSO4]).

[0133] 12.- Method according to any of the preceding numbered paragraphs, characterized in that, said solvent-based extraction is a multi-step extraction comprising the steps:

[0134] (i) bringing said polyvinyl chloride product into contact with at least one ionic liquid; and

[0135] (ii) bringing said polyvinyl chloride product into contact with supercritical carbon dioxide (CO2).

[0136] 13.- Method according to any of the preceding numbered paragraphs, characterized in that, said polyvinyl chloride product is brought into contact with said solvent, e.g. supercritical carbon dioxide (CO2) and / or an ionic liquid, during a contact time of between 5 and 60 minutes, preferably of between 10 and 45 minutes, more preferably of between 15 and 30 minutes.

[0137] 14.- Method according to any of the preceding numbered paragraphs, characterized in that, said polyvinyl chloride product is brought into contact with said solvent, e.g. supercritical carbon dioxide (CO2) and / or an ionic liquid, following a surface to volume ratio of between 1 : 1 and 1 : 10, preferably of between 1 :3 and 1 : 10.

[0138] 15.- Method according to any of the preceding numbered paragraphs, characterized in that, said method, prior to the step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, comprises the step of comminuting said polyvinyl chloride (PVC) products into granules, said granules having a particle size D90 of less than 2,5 mm, preferably of less than 1 mm, more preferably of less than 0,5 mm. 16.- Method according to any of the preceding numbered paragraphs, characterized in that, said method, prior to the step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction or, if present, prior to the step of comminuting said polyvinyl chloride (PVC) products into granules, comprises the step of mechanically separating non-polyvinyl chloride (non-PVC) material from polyvinyl chloride (PVC) material.

[0139] 17.- Method according to any of the preceding numbered paragraphs, characterized in that, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, comprises the step of washing said post-extraction polyvinyl chloride (PVC) products.

[0140] 18.- Method according to any of the preceding numbered paragraphs, characterized in that, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, wherein at least one component chosen from the group consisting of plasticizers, heavy metals, polar components, acrylic resins, organic components, pigments, additives and combinations thereof is extracted, comprises the step of purifying said at least one component.

[0141] 19.- Method according to numbered paragraph 18, characterized in that, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, thereby extracting at least plasticizers, comprises the step of separating nonphthalate plasticizers from phthalate plasticizers.

[0142] 20.- Method according to any of the preceding numbered paragraphs, characterized in that, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, thereby extracting at least plasticizers, comprises the step of converting phthalate plasticizers to non-phthalate plasticizers, preferably by means of a transesterification and / or hydrogenation reaction. 21.- Method according to any of the preceding numbered paragraphs, characterized in that, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, comprises the step of supplementing said post-extraction polyvinyl chloride (PVC) products with virgin polyvinyl chloride (PVC), plasticizers, compatibilizers, or combinations thereof.

[0143] 22.- Method according to any of the preceding numbered paragraphs, characterized in that, said polyvinyl chloride (PVC) products are floor or wall coverings, preferably floor or wall panels.

[0144] 23.- Method according to any of the preceding numbered paragraphs, characterized in that, said polyvinyl chloride (PVC) products comprise PVC in an amount of between 20 and 100 wt.%.

[0145] 24.- Method according to any of the preceding numbered paragraphs, characterized in that, said polyvinyl chloride (PVC) products comprise filler, preferably mineral filler, in an amount of between 0 and 80 wt.%.

[0146] 25.- Method according to any of the preceding numbered paragraphs, characterized in that, said polyvinyl chloride (PVC) products comprise plasticizers, preferably phthalate- based plasticizers, in an amount of between 1 and 50 phr, more preferably between 10 and 25 phr.

[0147] 26.- Method according to any of the preceding numbered paragraphs, characterized in that said solvent comprises supercritical carbon dioxide and / or an ionic liquid, and a cosolvent.

[0148] 27.- Method according to numbered paragraph 26, characterized in that said cosolvent has affinity to phthalates and / or leads to a swelling of said PVC products. 28.- Method according to numbered paragraph 26 or 27, characterized in that said cosolvent is chosen from the group consisting of water, methanol, ethyl acetate, methylene chloride, CHCh, acetone, cyclohexanone and tetrahydrofuran.

[0149] 29.- Method for recycling polyvinyl chloride products, preferably polyvinyl chloride floor or wall coverings, whether or not in accordance with any of the preceding paragraphs, said polyvinyl chloride forming a first thermoplastic polymer, characterized in that said polyvinyl chloride product to be recycled comprises at least a second thermoplastic polymer other than polyvinyl chloride, wherein said method comprises the step SI of subjecting said polyvinyl chloride products 1 to a solvent-based extraction and the step of separating at least partially said second thermoplastic polymer from said first thermoplastic polymer.

[0150] 30.- Method according to numbered paragraph 29, characterized in that said second thermoplastic polymer is polyethylene terephthalate or polypropylene or polyethylene.

[0151] 31. - Method according to numbered paragraph 29 or 30, characterized in that said second thermoplastic material is available in polyvinyl chloride free portion or layer of said product.

[0152] 32.- Method according to any of the preceding numbered paragraphs 29 to 31, characterized in that said polyvinyl chloride product is sheet-shaped, wherein the bottom of said polyvinyl chloride product is formed by a textile layer formed at least from fibers formed from said second thermoplastic material.

[0153] 33.- Method according to any of the preceding numbered paragraphs 29 to 32, characterized in that said polyvinyl chloride product is a sheet vinyl flooring product.

[0154] 34.- Method according to any of the preceding numbered paragraphs 29 to 33, characterized in that said step of separating at least comprises the exerting of mechanical force, preferably a shearing action, a grinding action and / or mechanical impact. 35.- Method according to any of the preceding numbered paragraphs, characterized in that said step of subjecting said polyvinyl chloride products 1 to a solvent-based extraction takes place in an extraction vessel, wherein at each time at least 5kg of polyvinyl chloride products 1 are present in said extraction vessel, and wherein said polyvinyl chloride products 1 preferably have a surface to volume ratio of 1 : 10 or higher as expressed in 1 / mm.

[0155] 36.- Method according to any of the preceding numbered paragraphs 29 to 34, characterized in that, said solvent-based extraction comprises extracting at least one component from the polyvinyl chloride PVC products, said component is chosen from the group of plasticizers, heavy metals, polar components, acrylic resins, organic components, pigments, additives, or combinations thereof.

[0156] 37.- Method according to numbered paragraph 36, characterized in that, said component is a plasticizer, preferably a phthalate-based plasticizer in accordance with formula I, wherein R and R’ may be the same or may be different, and wherein R and / or R’ are chosen from the group of CnHin+i, wherein n is an integer between 1 and 15, more preferably chosen from the group of diisononyl phthalate (DINP), di-(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), diisoheptyl phthalate (DIHP), di-n-octyl phthalate (DOP), diisooctyl phthalate (DIOP), diisodecyl phthalate (DIDP), or combinations thereof.

[0157] 38.- Method according to any of the preceding numbered paragraphs 29 to 37, characterized in that, said solvent comprises supercritical carbon dioxide (CO2). 39.- Method according to numbered paragraph 38, characterized in that, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a temperature of between 20 and 100 °C, preferably of between 50 and 95 °C, more preferably of between 75 and 90 °C.

[0158] 40.- Method according to numbered paragraph 38 or 39, characterized in that, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a pressure of between 20 and 50 MPa, preferably of between 30 and 50 MPa.

[0159] 41.- Method according to any of numbered paragraphs 29 to 37, characterized in that, said solvent comprises an ionic liquid.

[0160] 42.- Method according to numbered paragraph 41, characterized in that, said polyvinyl chloride product is brought into contact with the ionic liquid at a temperature of at least 100 °C, preferably of at least 150 °C.

[0161] 43.- Method according to numbered paragraph 41 or 42, characterized in that, said ionic liquid comprises one or more of l-butyl-3 -methyl imidazolium tetrafluoroborate ([BMIM][BF4]), l-butyl-3 -methyl imidazolium hexafluorophosphate ([BMIM][PF6]), 2,4-bis(2-hydroxypropyl)-l, 1,3,3-tetramethyl guanidinium tetrafluoroborate ([TMGHPO2] [BF4]), and tetramethyl guanidine lactate (TMGL).

[0162] 44.- Method according to any of numbered paragraphs 41 to 43, characterized in that, said ionic liquid is chosen from the group of l-octyl-3 -methyl imidazolium tetrafluoroborate ([C8mim][BF4]), l-octyl-3 -methyl imidazolium hexafluorophosphate ([C8mim][PF6]), triethylammonium hydrogen sulphate ([HNEt3][HSO4]).

[0163] 45.- Method according to any of numbered paragraphs 29 to 44, characterized in that, said solvent-based extraction is a multi-step extraction comprising the steps:

[0164] (i) bringing said polyvinyl chloride product into contact with at least one ionic liquid; and (ii) bringing said polyvinyl chloride product into contact with supercritical carbon dioxide (CO2).

[0165] 46.- Method according to any of numbered paragraphs 29 to 45, characterized in that, said polyvinyl chloride product is brought into contact with said solvent, e.g. supercritical carbon dioxide (CO2) and / or an ionic liquid, following a surface to volume ratio of between 3: 1 and 10: 1 as expressed in 1 / mm.

[0166] 47.- Method according to any of numbered paragraphs 29 to 46, characterized in that, said method, prior to the step of subjecting said polyvinyl chloride products to the solvent-based extraction, comprises the step of comminuting said polyvinyl chloride products into granules, said granules having a particle size D90 of less than 2.5 mm, preferably of less than 1 mm, more preferably of less than 0.5 mm.

[0167] 48.- Method according to any of numbered paragraphs 29 to 47, characterized in that, said polyvinyl chloride (PVC) products comprise PVC in an amount of between 20 and 95 wt.%.

[0168] 49.- Method according to any of numbered paragraphs 29 to 48, characterized in that, said polyvinyl chloride (PVC) products comprise filler, preferably mineral filler, in an amount of between 0 and 80 wt.%.

[0169] 50.- Method according to any of numbered paragraphs 29 to 49, characterized in that said solvent comprises supercritical carbon dioxide and / or an ionic liquid, and a cosolvent.

[0170] 51.- Method for manufacturing polyvinyl chloride (PVC) products, comprising the step of providing polyvinyl chloride (PVC) material, characterized in that said polyvinyl chloride (PVC) material is obtained by a method according to any of numbered paragraphs 29 to 50.

[0171] 52.- Floor or wall covering or floor or wall panel comprising a substrate and a top layer provided on said substrate, wherein said substrate comprises calcium carbonate, characterized in that at least a portion of said calcium carbonate is of a biological and / or a waste origin and / or is obtained by carbonatation of calcium oxide, wherein said substrate further comprises a moisture neutralizing agent .

[0172] 53.- Floor or wall covering or floor or wall panel according to numbered paragraph 52, characterized in that said calcium carbonate is at least obtained from egg shells, at least obtained from snail shells or seafood shells, at least obtained from skeletons, at least obtained from exoskeletons, at least obtained from paper waste, or at least obtained as waste minerals from the exploitation of shale gas.

[0173] 54.- Floor or wall covering or floor or wall panel according to numbered paragraph 52 or 53, wherein said substrate comprises a plurality of layers, wherein at least a first layer comprises said calcium carbonate from biological, waste and / or carbonatation origin, and a second layer comprises no or less such calcium carbonate.

[0174] 55.- Floor or wall covering or floor or wall panel according to numbered paragraph 54, characterized in that said first layer is distanced from the top layer at least by said second layer.

[0175] 56.- Method of manufacturing a floor or wall covering or a floor or wall panel, wherein said method at least comprises the following steps:

[0176] - the step of providing calcium carbonate;

[0177] - the step of providing a substrate material comprising said calcium carbonate and said moisture neutralizing agent; characterized in that said calcium carbonate is of a biological and / or a waste origin and / or is obtained by carbonatation of calcium oxide.

[0178] 57.- Method according to numbered paragraph 56, characterized in that said substrate is a filled synthetic material, wherein the filler material comprises said calcium carbonate, wherein said synthetic material is preferably a thermoplastic material chosen from the list consisting of polyvinyl chloride, polyethylene terephthalate, polypropylene, polyethylene and polyurethane. 58.- Method according to numbered paragraph 56 or 57, characterized in that at least 50 wt% of said filled synthetic material is said filler material.

[0179] 59.- Method or product according to any of numbered paragraphs 52 to 58, characterized in that said moisture neutralizing agent is or comprises porous particles and / or aluminum silicate particles and / or silica particles and / or particles having a BET specific surface area, as measured in accordance with ISO 9288:2022, of 5 to 500 m2 / g, preferably 50 to 350 m2 / g or 125 to 250 m2 / g.

[0180] 60.- Method or product according to any of numbered paragraphs 52 to 59, characterized in that said moisture neutralizing agent is or comprises an agent that reacts or binds to water and / or that said moisture neutralizing agent is or comprises calcium oxide.

[0181] 61.- Method for manufacturing floor or wall coverings or floor or wall panels, wherein said method at least comprises the following steps:

[0182] - the step of providing a mineral filler, e.g. calcium carbonate;

[0183] - the step of providing a substrate material comprising said mineral filler, e.g. said calcium carbonate; characterized in that said step of providing said mineral filler comprises a drying treatment wherein the residual moisture content of said filler is brought to 1% or below, preferably to 0,5% or below.

[0184] 62.- Method according to numbered paragraph 61, characterized in that said mineral filler comprises calcium carbonate of a biological and / or a waste origin and / or is obtained by carbonatation of calcium oxide.

[0185] 63.- Floor or wall covering or a floor or wall panel comprising a substrate and a top layer provided on said substrate, wherein said substrate comprises at least a first layer and a second layer, wherein said first layer comprises mineral filler material from a biological and / or waste origin and / or is obtained by carbonatation of calcium oxide, and said second layer is free from such mineral filler material or comprises such mineral filler material in a lesser amount, for example less than half the weight amount, wherein said first layer is distanced from said top layer at least by said second layer.

[0186] 64.- Product according to numbered paragraph 63, characterized in that both said first and second layer comprise polyvinyl chloride or polypropylene or polyethylene terephthalate or polyethylene or polyurethane, wherein also said second layer may be filled with a mineral filler material, albeit preferably with a virgin mineral filler material.

[0187] The aspects and concepts disclosed in the claims and / or numbered paragraphs may be combined with one another as long as they are not mutually contradictory. The present invention is by no means limited to the embodiments described above, however such methods or products may be realized according to various variants without departing from the scope of the present invention.

Claims

Claims1.- Method for recycling polyvinyl chloride products, preferably polyvinyl chloride floor or wall coverings, said polyvinyl chloride forming a first thermoplastic polymer, characterized in that said polyvinyl chloride product to be recycled comprises at least a second thermoplastic polymer other than polyvinyl chloride, wherein said method comprises the step (SI) of subjecting said polyvinyl chloride products (1) to a solventbased extraction and the step of separating at least partially said second thermoplastic polymer from said first thermoplastic polymer.2.- Method according to claim 1, characterized in that said second thermoplastic polymer is polyethylene terephthalate or polypropylene or polyethylene.3.- Method according to claim 1 or 2, characterized in that said second thermoplastic material is available in polyvinyl chloride free portion or layer of said product.4.- Method according to any of the preceding claims, characterized in that said polyvinyl chloride product is sheet-shaped, wherein the bottom of said polyvinyl chloride product is formed by a textile layer formed at least from fibers formed from said second thermoplastic material.5.- Method according to any of the preceding claims, characterized in that said polyvinyl chloride product is a sheet vinyl flooring product.6.- Method according to any of the preceding claims, characterized in that said step of separating at least comprises the exerting of mechanical force, preferably a shearing action, a grinding action and / or mechanical impact.7.- Method according to any of the preceding claims, characterized in that said step of subjecting said polyvinyl chloride products (1) to a solvent-based extraction takes place in an extraction vessel, wherein at each time at least 5kg of polyvinyl chloride products(1) are present in said extraction vessel, and wherein said polyvinyl chloride products (1) preferably have a surface to volume ratio of 1 : 10 or higher as expressed in 1 / mm.8.- Method according to aby of the preceding claims, characterized in that, said solventbased extraction comprises extracting at least one component from the polyvinyl chloride (PVC) products, said component is chosen from the group of plasticizers, heavy metals, polar components, acrylic resins, organic components, pigments, additives, or combinations thereof.9.- Method according to claim 8, characterized in that, said component is a plasticizer, preferably a phthalate-based plasticizer in accordance with formula I, wherein R and R’ may be the same or may be different, and wherein R and / or R’ are chosen from the group of CnHin+i, wherein n is an integer between 1 and 15, more preferably chosen from the group of diisononyl phthalate (DINP), di-(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), diisoheptyl phthalate (DIHP), di-n-octyl phthalate (DOP), diisooctyl phthalate (DIOP), diisodecyl phthalate (DIDP), or combinations thereof.10.- Method according to any of the preceding claims, characterized in that, said solvent comprises supercritical carbon dioxide (CO2).11.- Method according to claim 10, characterized in that, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a temperature of between 20 and 100 °C, preferably of between 50 and 95 °C, more preferably of between 75 and 90 °C.12.- Method according to claim 10 or 11, characterized in that, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a pressure of between 20 and 50 MPa, preferably of between 30 and 50 MPa.13.- Method according to any of claims 1 to 9, characterized in that, said solvent comprises an ionic liquid.14.- Method according to claim 13, characterized in that, said polyvinyl chloride product is brought into contact with the ionic liquid at a temperature of at least 100 °C, preferably of at least 150 °C.15.- Method according to claim 13 or 14, characterized in that, said ionic liquid comprises one or more of l-butyl-3 -methyl imidazolium tetrafluoroborate ([BMIM][BF4]), l-butyl-3 -methyl imidazolium hexafluorophosphate ([BMIM][PF6]), 2,4-bis(2-hydroxypropyl)-l, 1,3,3-tetramethyl guanidinium tetrafluoroborate ([TMGHPO2] [BF4]), and tetramethyl guanidine lactate (TMGL).16.- Method according to any of claims 13 to 15, characterized in that, said ionic liquid is chosen from the group of l-octyl-3 -methyl imidazolium tetrafluoroborate ([C8mim][BF4]), l-octyl-3 -methyl imidazolium hexafluorophosphate ([C8mim][PF6]), triethylammonium hydrogen sulphate ([HNEt3][HSO4]).17.- Method according to any of claims 1 to 16, characterized in that, said solvent-based extraction is a multi-step extraction comprising the steps:(i) bringing said polyvinyl chloride product into contact with at least one ionic liquid; and(ii) bringing said polyvinyl chloride product into contact with supercritical carbon dioxide (CO2).18.- Method according to any of claims 1 to 17, characterized in that, said polyvinyl chloride product is brought into contact with said solvent, e.g. supercritical carbondioxide (CO2) and / or an ionic liquid, following a surface to volume ratio of between 3: 1 and 10: 1 as expressed in 1 / mm.19.- Method according to any of claims 1 to 18, characterized in that, said method, prior to the step of subjecting said polyvinyl chloride products to the solvent-based extraction, comprises the step of comminuting said polyvinyl chloride products into granules, said granules having a particle size D90 of less than 2.5 mm, preferably of less than 1 mm, more preferably of less than 0.5 mm.20.- Method according to any of claims 1 to 19, characterized in that, said polyvinyl chloride (PVC) products comprise PVC in an amount of between 20 and 95 wt.%.21.- Method according to any of claims 1 to 20, characterized in that, said polyvinyl chloride (PVC) products comprise filler, preferably mineral filler, in an amount of between 0 and 80 wt.%.22.- Method according to any of claims 1 to 21, characterized in that said solvent comprises supercritical carbon dioxide and / or an ionic liquid, and a cosolvent.23.- Method for manufacturing polyvinyl chloride (PVC) products, comprising the step of providing polyvinyl chloride (PVC) material, characterized in that said polyvinyl chloride (PVC) material is obtained by a method according to any of claims 1 to 22.24.- Floor or wall covering or floor or wall panel comprising a substrate and a top layer provided on said substrate, wherein said substrate comprises calcium carbonate, characterized in that at least a portion of said calcium carbonate is of a biological and / or a waste origin and / or is obtained by carbonatation of calcium oxide, wherein said substrate further comprises a moisture neutralizing agent.25.- Floor or wall covering or floor or wall panel according to claim 24, characterized in that said calcium carbonate is at least obtained from egg shells, at least obtained from snail shells or seafood shells, at least obtained from skeletons, at least obtained fromexoskeletons, at least obtained from paper waste, or at least obtained as waste minerals from the exploitation of shale gas.26.- Floor or wall covering or floor or wall panel according to claim 24 or 25, wherein said substrate comprises a plurality of layers, wherein at least a first layer comprises said calcium carbonate from biological, waste and / or carbonatation origin, and a second layer comprises no or less such calcium carbonate.27.- Floor or wall covering or floor or wall panel according to claim 26, characterized in that said first layer is distanced from the top layer at least by said second layer.28.- Method of manufacturing a floor or wall covering or a floor or wall panel, wherein said method at least comprises the following steps:- the step of providing calcium carbonate;- the step of providing a substrate material comprising said calcium carbonate and said moisture neutralizing agent; characterized in that said calcium carbonate is of a biological and / or a waste origin and / or is obtained by carbonatation of calcium oxide.29.- Method according to claim 28, characterized in that said substrate is a filled synthetic material, wherein the filler material comprises said calcium carbonate, wherein said synthetic material is preferably a thermoplastic material chosen from the list consisting of polyvinyl chloride, polyethylene terephthalate, polypropylene, polyethylene and polyurethane.30.- Method according to claim 28 or 29, characterized in that at least 50 wt% of said filled synthetic material is said filler material.31.- Method or product according to any of the claims 24-30, characterized in that said moisture neutralizing agent is or comprises porous particles and / or aluminum silicate particles and / or silica particles and / or particles having a BET specific surface area, asmeasured in accordance with ISO 9288:2022, of 5 to 500 m2 / g, preferably 50 to 350 m2 / g or 125 to 250 m2 / g.32.- Method or product according to any of the claims 24-31, characterized in that said moisture neutralizing agent is or comprises an agent that reacts or binds to water and / or that said moisture neutralizing agent is or comprises calcium oxide.33.- Method for manufacturing floor or wall coverings or floor or wall panels, wherein said method at least comprises the following steps:- the step of providing a mineral filler, e.g. calcium carbonate;- the step of providing a substrate material comprising said mineral filler, e.g. said calcium carbonate; characterized in that said step of providing said mineral filler comprises a drying treatment wherein the residual moisture content of said filler is brought to 1% or below, preferably to 0,5% or below.34.- Method according to claim 33, characterized in that said mineral filler comprises calcium carbonate of a biological and / or a waste origin and / or is obtained by carbonatation of calcium oxide.35.- Floor or wall covering or a floor or wall panel comprising a substrate and a top layer provided on said substrate, wherein said substrate comprises at least a first layer and a second layer, wherein said first layer comprises mineral filler material from a biological and / or waste origin and / or is obtained by carbonatation of calcium oxide, and said second layer is free from such mineral filler material or comprises such mineral filler material in a lesser amount, for example less than half the weight amount, wherein said first layer is distanced from said top layer at least by said second layer.36.- Product according to claim 35, characterized in that both said first and second layer comprise polyvinyl chloride or polypropylene or polyethylene terephthalate or polyethylene or polyurethane, wherein also said second layer may be filled with a mineral filler material, albeit preferably with a virgin mineral filler material.37.- Method for recycling polyvinyl chloride (PVC) products, preferably polyvinyl chloride (PVC) floor or wall coverings, characterized in that, said method comprises the step SI of subjecting said polyvinyl chloride (PVC) products 1 to a solvent-based extraction.38.- Method according to claim 37, characterized in that, said solvent-based extraction comprises extracting at least one component from the polyvinyl chloride (PVC) products, said component is chosen from the group of plasticizers, heavy metals, polar components, acrylic resins, organic components, pigments, additives, or combinations thereof.39.- Method according to claim 38, characterized in that, said component is a plasticizer, preferably a phthalate-based plasticizer in accordance with formula I, wherein R and R’ may be the same or may be different, and wherein R and / or R’ are chosen from the group of CnHin+i, wherein n is an integer between 1 and 15, more preferably chosen from the group of diisononyl phthalate (DINP), di-(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), diisoheptyl phthalate (DIHP), di-n-octyl phthalate (DOP), diisooctyl phthalate (DIOP), diisodecyl phthalate (DIDP), or combinations thereof.40.- Method according to any of the claims 37-39, characterized in that, said solventbased extraction comprises bringing said polyvinyl chloride product 1 into contact with at least one solvent, preferably at least one liquid solvent.41.- Method according to any of the claims 37-40, characterized in that, said solvent comprises supercritical carbon dioxide (CO2).42.- Method according to claim 41, characterized in that, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a temperature of between 20 and 100 °C, preferably of between 50 and 95 °C, more preferably of between 75 and 90 °C.43.- Method according to claim 41 or 42, characterized in that, said polyvinyl chloride product is brought into contact with supercritical carbon dioxide (CO2) at a pressure of between 20 and 50 MPa, preferably of between 30 and 50 MPa.44.- Method according to any of the claims 37-43, characterized in that, said solvent comprises an ionic liquid.45.- Method according to claim 44, characterized in that, said polyvinyl chloride product is brought into contact with the ionic liquid at a temperature of at least 100 °C, preferably of at least 150 °C.

46. Method according to claim 44 or 45, characterized in that, said ionic liquid comprises one or more of 1 -butyl -3 -methyl imidazolium tetrafluoroborate ([BMIM][BF4]), 1- butyl-3 -methyl imidazolium hexafluorophosphate ([BMIM][PF6]), 2,4-bis(2- hydroxypropyl)- 1,1, 3, 3 -tetramethyl guanidinium tetrafluoroborate ([TMGHPO2] [BF4]), and tetramethyl guanidine lactate (TMGL).47.- Method according to any of the claims 44-46, characterized in that, said ionic liquid is chosen from the group of l-octyl-3 -methyl imidazolium tetrafluoroborate ([C8mim][BF4]), l-octyl-3 -methyl imidazolium hexafluorophosphate ([C8mim][PF6]), triethylammonium hydrogen sulphate ([HNEt3][HSO4]).48.- Method according to any of the claims 37-47, characterized in that, said solventbased extraction is a multi-step extraction comprising the steps:(i) bringing said polyvinyl chloride product into contact with at least one ionic liquid; and(ii) bringing said polyvinyl chloride product into contact with supercritical carbon dioxide (CO2).49.- Method according to any of the claims 37-48, characterized in that, said polyvinyl chloride product is brought into contact with said solvent, e.g. supercritical carbon dioxide (CO2) and / or an ionic liquid, during a contact time of between 5 and 60 minutes, preferably of between 10 and 45 minutes, more preferably of between 15 and 30 minutes.50.- Method according to any of the claims 37-49, characterized in that, said polyvinyl chloride product is brought into contact with said solvent, e.g. supercritical carbon dioxide (CO2) and / or an ionic liquid, following a surface to volume ratio of between 1 : 1 and 1 : 10, preferably of between 1 :3 and 1 : 10.51.- Method according to any of the claims 37-50, characterized in that, said method, prior to the step of subjecting said polyvinyl chloride (PVC) products to the solventbased extraction, comprises the step of comminuting said polyvinyl chloride (PVC) products into granules, said granules having a particle size D90 of less than 2,5 mm, preferably of less than 1 mm, more preferably of less than 0,5 mm.52.- Method according to any of the claims 37-51, characterized in that, said method, prior to the step of subjecting said polyvinyl chloride (PVC) products to the solventbased extraction or, if present, prior to the step of comminuting said polyvinyl chloride (PVC) products into granules, comprises the step of mechanically separating nonpolyvinyl chloride (non-PVC) material from polyvinyl chloride (PVC) material.53.- Method according to any of the claims 37-52, characterized in that, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, comprises the step of washing said post-extraction polyvinyl chloride (PVC) products.54.- Method according to any of the claims 37-53, characterized in that, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, wherein at least one component chosen from the group consisting of plasticizers, heavy metals, polar components, acrylic resins, organic components, pigments, additives and combinations thereof is extracted, comprises the step of purifying said at least one component.55.- Method according to claim 54, characterized in that, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, thereby extracting at least plasticizers, comprises the step of separating non-phthalate plasticizers from phthalate plasticizers.56.- Method according to any of the claims 37-55, characterized in that, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, thereby extracting at least plasticizers, comprises the step of converting phthalate plasticizers to non-phthalate plasticizers, preferably by means of a transesterification and / or hydrogenation reaction.57.- Method according to any of the claims 37-56, characterized in that, said method, after said step of subjecting said polyvinyl chloride (PVC) products to the solvent-based extraction, comprises the step of supplementing said post-extraction polyvinyl chloride (PVC) products with virgin polyvinyl chloride (PVC), plasticizers, compatibilizers, or combinations thereof.58.- Method according to any of the claims 37-57, characterized in that, said polyvinyl chloride (PVC) products are floor or wall coverings, preferably floor or wall panels.59.- Method according to any of the claims 37-58, characterized in that, said polyvinyl chloride (PVC) products comprise PVC in an amount of between 20 and 100 wt.%.60.- Method according to any of the claims 37-59, characterized in that, said polyvinyl chloride (PVC) products comprise filler, preferably mineral filler, in an amount of between 0 and 80 wt.%.61.- Method according to any of the claims 37-60, characterized in that, said polyvinyl chloride (PVC) products comprise plasticizers, preferably phthalate-based plasticizers, in an amount of between 1 and 50 phr, more preferably between 10 and 25 phr.62.- Method according to any of the claims 37-61, characterized in that said solvent comprises supercritical carbon dioxide and / or an ionic liquid, and a cosolvent.63.- Method according to claim 62, characterized in that said cosolvent has affinity to phthalates and / or leads to a swelling of said PVC products.64.- Method according to claim 62 or 63, characterized in that said cosolvent is chosen from the group consisting of water, methanol, ethyl acetate, methylene chloride, CHCh, acetone, cyclohexanone and tetrahydrofuran.

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