Sustainable multi-layer composite

Abstract

The invention relates to a multilayer composite, in particular an artificial leather, having a textile layer and at least one functional layer provided thereon, wherein the textile layer is formed from a fibrous material, which is a polyester, and the functional layer is based on a polyester composition comprising a polymer matrix and a plasticizing component, the polymer matrix being formed from an ester-based polymer such that the entire multilayer composite has a polyester content of at least 80 wt.%, based on the weight of the multilayer composite. The invention further relates to seating furniture, in particular for use in an automobile, having a surface made of such a multilayer composite. In this way, soft and elastic but nevertheless abrasion-resistant structures can be produced which are completely mechanically recyclable.

Description

[0001] 202403270

[0002] 1

[0003] Description

[0004] Sustainable multi-layer composite

[0005] The invention relates to a multilayer composite, in particular an artificial leather, comprising a textile layer and at least one functional layer arranged thereon. The invention also relates to seating furniture, particularly for use in automobiles, comprising a surface made of such a multilayer composite. In this way, soft, elastic, yet abrasion-resistant constructions can be produced that are fully mechanically recyclable.

[0006] Artificial leathers are decorative and functional surfaces made from synthetic materials that mimic the look and feel of genuine leather. They consist of a multi-layered composite material made from a soft polymer combined with a textile backing, typically based on polyurethane or polyvinyl chloride. To further replicate the look and feel of leather, these surfaces are sometimes given a grained texture. Common materials used for textile backings include nylon, cotton, polyester, and similar fabrics.

[0007] Thermoplastic polyester fibers are economically recyclable, meaning that only a fraction of the energy is required for the predominantly mechanical recycling process compared to producing the material from scratch. Furthermore, recycling is beneficial simply because it conserves fossil resources in the production of a new product. It also avoids the CO2 emissions that would have been generated if the old product were incinerated. Thus, the recycled product would have a significantly smaller carbon footprint and therefore make a major contribution to environmental protection. However, mechanical recycling requires the availability of nearly pure waste materials. Reprocessing or separating the surface coating from the textile substrate proves to be complex and uneconomical, so the 202403270

[0008] 2

[0009] Recycling has therefore not occurred in practice. Consequently, the only alternatives are gasification or incineration of the structure for energy recovery.

[0010] The invention is therefore based on the objective of providing a multilayer composite structure (monomaterial construction) that can be separated as cleanly as possible and offers the option of mechanical recycling, which is suitable for use as artificial leather in the interior of an automobile or a building, in particular for use as seating furniture, or for use as a fashion item, e.g.

[0011] Handbags are suitable for this purpose. A soft, mono-material, multi-layer construction is necessary, which offers high flexibility yet sufficient abrasion resistance.

[0012] This problem is solved by the features of independent claims 1 and 15. Further advantageous embodiments are disclosed in the dependent claims.

[0013] According to the invention, the composite material comprises a textile layer and at least one functional layer arranged thereon. In a particularly advantageous embodiment, the composite material is an artificial leather.

[0014] The multilayer composite is therefore made up of at least two layers, with each layer being formed from one or more layers.

[0015] A layer, as defined in the invention, is a mass of material spread over a surface. A layer consists of a material composition, e.g., a polymer composition, a fiber composite, a coating in a dimensionally stable state, a substructure textile, foam, or a spacer system, which has been bonded using appropriate methods (adhesive bonding, flame lamination, etc.).

[0016] A layer within the meaning of the invention is a mass of material spread over a surface. A layer can be formed from one or more layers, which can be arranged above or below one another. A layer formed from a single layer can also be referred to as a layer and vice versa. Multiple layers can, in principle, be arranged above or below one another. 202403270

[0017] 3. Multilayer coatings are preferably, but not necessarily, formed from layers of the same material composition. In this context, material compositions are considered identical if they do not differ significantly with respect to their chemical components. Non-essential chemical components are mixture constituents that do not affect the chemical properties of the entire mixture, e.g., color pigments, foaming agents, etc. The quantity of the chemical components can vary within a small range. For example, a top coat of paint can comprise 1, 2, 5, or 7 layers of a paint composition.

[0018] According to the invention, a textile layer is arranged alongside the functional layer. This preferably forms the bottom layer of the multilayer composite, so that the functional layer is arranged above the textile layer. "Textiles" refers to both textile fibers and raw materials, semi-finished products, or finished products of the textile industry. For the purposes of this invention, "textile" refers to textile fabrics (also textile fabrics). According to the invention, this refers to structures made of fibers of a chemical nature. Specifically, the fibers that form the textile fabric are made of one or more polyesters. This means that the polyester content in the textile layer, based on the weight of the pure fibers, is 100% by weight (i.e., including minute quantities of necessary process additives that are included in the fibers for processing purposes).A fiber is a linear, elementary structure composed of a fibrous material. A fiber is a thin, flexible structure relative to its length, with a length-to-diameter ratio of at least 1000:1. The fiber has an external shape (longitudinal shape: straight or crimped; cross-sectional shape: round, angular, etc.) and is solid or hollow. It can be continuous (filament) or of limited length (spun fiber).

[0019] According to the invention, the fiber material forming the textile layer is a polyester (PES). The PES fiber is very tear- and abrasion-resistant and absorbs very little moisture. The textile surface composite can, in principle, be processed by any qualified person. 202403270

[0020] 4. The textile must have a known fiber structure (e.g., staple fiber and / or filament fiber). For example, the textile can be a woven, knitted, non-woven, braided, or crocheted fabric, or a mixture thereof. Preferably, it is a knitted and / or non-woven fabric.

[0021] The textile is preferably composed of a material selected from the following list: poly(ethylene-2,5-furan dicarboxylate (PEF), polylactic acid (PLA), polyadipate rephthalate (e.g., polybutylene adipate rephthalate (PBAT)), polyethylene terephthalate (PET), recycled polyethylene terephthalate (rPET), or mixtures thereof. Fibers made of polyadipate rephthalate (e.g., polybutylene adipate rephthalate (PBAT)) are preferred. These are preferably also industrially compostable.

[0022] In preferred embodiments, the polyester fibers of the textile layer have a higher melting point than the polyester-based polymers of the functional layer. Preferably, the melting point of the polyester fibers of the textile layer is at least 10°C, and in particular 30°C, above the melting point of the polyester-based polymer of the layer directly on top of it, especially the functional layer. For example, suitable fibers made of PET or rPET have a melting point of 230°C to 270°C, preferably approximately 240°C to 260°C, suitable fibers made of PBAT have a melting point of 110°C to 130°C, and suitable fibers made of PBSeT have a melting point of 140°C to 160°C. The melting points given are measured according to ISO 11357-3:2018.

[0023] Due to certain applications requiring a certain lifespan and stability, e.g., in automotive interior applications, PET or recycled PET is particularly preferred. These materials have a melting point of 250 °C, are very tear-resistant, elastic, and thermoplastic, as well as light- and weather-resistant and exceptionally durable. Unless otherwise specified, the melting points are determined using Dynamic Scanning Calorimetry (DSC), based on DIN EN ISO 11357-1, with a heating rate of 20 °C / min. In particularly preferred 202403270

[0024] 5

[0025] In certain embodiments, the PET fibers have a maximum tensile strength of over 2300 N / 5cm, measured according to EN ISO 13 934-1 and / or a basis weight of at least 155 g / m². 2 , measured according to DIN EN 12 127.

[0026] The multilayer composite according to the invention has a functional layer, preferably arranged above the textile layer and thus on the visible side. The functional layer is formed from a polyester composition. The polyester composition comprises at least one polymer matrix, which includes an ester-based polymer.

[0027] A polymer matrix within the meaning of the present invention is a planar, three-dimensional (at the molecular level) arrangement of polymer chains that constitute the main component (over 50 wt.% based on the formed layer or layer) of a polymer composition. The planar spreading of the individual polymer or the mixture of polymers results from the film-forming properties of said polymer or mixture of polymers. The polymer matrix characterizes the properties of a layer and serves as a medium in which other substances, e.g., plasticizers, fillers, flame retardants, etc., can be integrated.

[0028] In preferred embodiments, bio-based, bioattributed, fully or partially biodegradable and / or fully or partially recycled ester-based polymers can be used as ester-based polymers. For example, PBT (polybutylene terephthalate), PET (polyethylene terephthalate), PLA (polylactide), especially poly-L-lactic acid (PLLA), poly-D-lactic acid (PDLA), poly-D / L-lactic acid (PDLLA), PBAT (polybutylene adipate terephthalate), PBS (polybutylene succinate), PBSe (polybutylene sebaceous aureate), PEF (polyethylene furanoate), PBF (polybutylene furanoate), PPF (polypropylene furanoate), PTT (polytrimethylene terephthalate), PPN (polypropylene naphthalate), PPT (polypropylene terephthalate), PEN (polyethylene naphthalate), PBN (polybutylene naphthalate), PEF (polyethylene furanoate), PLA (polylactic acid), PHAs (polyhydroxyalkanoates) such as PHB (polyhydroxybutyrate), PAR (polyarylates), especially aromatic polyesters, 202403270

[0029] 6 and mixtures thereof may be used. Copolyesters made from the compounds listed above may also be used. The melting points of suitable polyesters for use in the functional layer are in the range of 60 °C to 250 °C, measured according to ISO 11357-3:2018. The hardness of the polyesters is preferably in the range of 45 Shore A to 100 Shore D (measured according to DIN 53505).

[0030] Preferably, the ester-based polymer in the polyester composition is selected from the group consisting of polybutylene sebacate (PBSe), polyhydroxyalkanoates (PHAs) such as polyhydroxybutyrate (PHB), polybutylene succinate (PBS), polybutylene sebacate co-terephthalate (PBSeT), polybutylene adipate co-terephthalate (PBAT), polyester polyurethane (PES / PU), polylactic acid (PLA), glycol-modified polyethylene terephthalate (PETG), polyethylene co-isosorbide terephthalate (PEIT), and mixtures thereof.

[0031] In particularly preferred embodiments, the polymer composition comprises an ester-based polymer selected from the group consisting of polybutylene sebacate (PBSe), polybutylene sebacate co-terephthalate (PBSeT), and / or polybutylene adipate co-terephthalate (PBAT). Surprisingly, these polyester types exhibited high flexibility and elasticity while simultaneously displaying high abrasion resistance, thus eliminating the need for subsequent painting.

[0032] The polymer composition according to the invention comprises, in addition to the ester-based polymer, a plasticizing component. The plasticizing component can be an internal plasticizer and / or an external plasticizer.

[0033] An internal plasticizer within the meaning of the present invention is a group of molecular units covalently bonded to the polyester, e.g., polymer blocks additionally incorporated into the polyester molecular framework. This increases the distances between the individual macromolecules, reduces the intermolecular forces of attraction, and increases chain mobility. In this way, the 202403270

[0034] 7

[0035] Plasticizing components inherent in the polymer matrix that remain unchanged over time and cannot diffuse out of the matrix.

[0036] Preferably, the internal plasticizer is a group covalently bonded to the polyester-based polymer matrix, selected from the list consisting of ether-based polymer blocks, urethane-based polymer blocks, imine-based polymer blocks, amine-based polymer blocks, (alkane and / or alkene and / or alkyne)-based polymer blocks, and mixtures thereof. The polymer blocks can be of different chain lengths, linear or branched, saturated or unsaturated. Ether-based and urethane-based polymer blocks are preferred according to the invention. In a particularly preferred embodiment, the polyester-based polymer and the plasticizing component are a copolymer of polyester and polyether and / or a polyurethane and polyester. According to the invention, the polyester content in the copolymer is not less than 50 wt.% based on the weight of the crude copolymer.According to the invention, the proportion of the internal plasticizer in the polyester copolymer is not higher than 40 wt.% based on the weight of the crude copolymer.

[0037] Alternatively or additionally, the plasticizing component can be an external plasticizer. An external plasticizer within the meaning of the invention is a molecule that is not covalently bonded to the polyester polymer. For example, the molecule can be added to the polyester and interact with the polymer matrix via physical interactions. These plasticizing molecules are smaller than the polymer chains of the polymer matrix (at most 10,000 g / mol) and exhibit a correspondingly higher mobility. These molecules can arrange themselves between the polymer molecules of the polymer matrix and loosen the matrix polymer chain. This also makes the chain molecules of the polymer matrix more mobile. The softness and elasticity of the polymer matrix increase. This type of plasticizing is particularly advantageous when only small amounts, in particular less than 30 wt.%, preferably less than 20 wt.%, and especially preferably less than 10 wt.%, are required.- % of external plasticizer, based on the weight of the mixture of 202403270.

[0038] 8

[0039] Polyester-based polymer and the outer plasticizer are required. This is particularly the case when the plasticizing component is an inner and an outer plasticizer.

[0040] In preferred embodiments, the external plasticizer has a molar mass of 200 to 3000 g / mol.

[0041] Alternatively or additionally, the external plasticizer is selected from the list consisting of citrates, trimellites, adipates, succinates, sebacates, phthalates, epoxidized and / or saturated natural oils, in particular soybean oil, glycerin, isosorbide compounds, polyethylene glycols or mixtures thereof.

[0042] It is particularly preferred that the polyester composition of the functional layer comprises at least 50 wt.%, preferably at least 60 wt.%, most preferably at least 70 wt.%, based on the weight of the functional layer, the mixture of the polyester-based polymer and the plasticizing component. This allows for a good compromise between maximizing the polyester content and achieving the required mechanical properties for use as synthetic leather.

[0043] The multilayer composite according to the invention, in particular an artificial leather, has a total polyester content of at least 80 wt.%, preferably at least 90 wt.%, most preferably at least 95 wt.%, based on the weight of the multilayer composite, i.e., based on the totality of all layers. In this way, a polyester monomaterial construction is obtained. This is completely meltable and suitable for direct further processing without the need for a prior, complex, and energy-intensive separation of the individual layers of the multilayer composite, in particular the artificial leather. Depending on the polyester content, various products can be manufactured from the melted material. For example, the resulting recyclate can be used as a new layer structure or a film for various surface applications, e.g., 202403270

[0044] 9

[0045] Upholstery materials, e.g. seating furniture, floor coverings, surface materials for furniture and / or kitchen surfaces, are used.

[0046] The polyester-based monomaterial is particularly suitable for seating applications due to its softness, flexibility, and simultaneous abrasion resistance. A particularly preferred embodiment is the use of the multilayer composite for surfaces in the automotive sector, e.g., car seats, instrument panels, door trim, etc.

[0047] Preferably, at least one layer of the multilayer composite is produced by a coating process (also called coating method). For example, the functional layer of the entire multilayer composite can be produced by coating, while the remaining layers are applied by a calendering or extrusion process. Alternatively, all layers of the multilayer composite can be applied to the textile substrate using a coating process.

[0048] The coating process generally involves applying the coatings using a low-viscosity system. A doctor blade (e.g., air-operated or blanket-applied) or a roller is particularly suitable as an aid. The coating itself is carried out as a direct or reverse coating process. The low-viscosity system contains at least one dispersed or emulsified polyester and a plasticizing component. Aromatic and aliphatic di- or multifunctional carbodiimides, isocyanates, epoxides, and acid anhydrides may also be present in the polyester dispersion or emulsion for chain extension or three-dimensional crosslinking of the polyester chains.

[0049] The multilayer composite system can be produced directly by applying polyester dispersions or emulsions to the textile substrate (textile layer). After applying an initial liquid polymer composition, it is dried by applying heat, fusing the polymer powders or dispersion particles. The temperatures for this are in the range of 80 to 240 °C. Further layers can be added.

[0050] Ten coats are applied, and the reverse side of the textile substrate is also coated. Such procedures are familiar to qualified personnel and require no further explanation.

[0051] The multilayer composite system can alternatively be produced using the reverse coating process. In this process, the appropriate polyester compound, as a polyester dispersion or emulsion, is applied to a coating substrate, such as a textured carrier (polymer or metal), or embossed or unembossed release paper. A textile substrate can then be embedded into the still-liquid or highly viscous compound. Alternatively, a first layer can be dried, fused / sintered, and optionally crosslinked before a further layer is applied, into which the textile carrier is embedded. After subsequent drying and fusion, the structure can be peeled from the substrate, or further coatings can be applied using polyester compound. Such processes are also familiar to qualified personnel and require no further explanation.

[0052] In contrast to extruded (solid) layers, a functional layer can be achieved that lies within the textile substrate. Furthermore, the use of polymer dispersions for the production of the multilayer composite system enables the in-situ crosslinking of existing polymers.

[0053] In contrast to an extruded adhesion layer, the coated adhesion layer penetrates the textile partially in liquid form and only hardens within the textile. This results in a hybrid layer of textile and adhesion layer. This creates enhanced adhesion between the textile and the applied layers. Due to the hybrid layer, recycling proves to be particularly energy-intensive, as the different polymers must be separated. According to the invention, both the textile layer and the functional layer, and thus also the hybrid layer of the multilayer composite formed by the coating process, are based on the same type of polymer, namely a polyester (mixture). Therefore, the entire composite can be recycled without prior [202403270].

[0054] 11

[0055] The material is separated, melted down, and thus recycled without increased energy requirements.

[0056] Preferably, dispersions of polyester polymer powder and polyester emulsions are used to produce the layers. The dispersions are prepared by mixing and dispersing polyester powder and water with the addition of suitable dispersing agents, thickeners such as polyester acrylates, alginates, rheology aids, and leveling agents.

[0057] Additionally, thixotropic additives such as polyester fibers (0.1-500 nm) with a high aspect ratio can be used to adjust the rheological properties.

[0058] The advantage of powder dispersions lies in the fact that excess, unused material can be dried without forming a film, allowing it to be reused as powder for the emulsion. The powders preferably have a particle size of 0.01–200 pm. The mean particle size is determined according to ISO 13320 using laser diffraction spectroscopy (LDS).

[0059] The dispersions are finely dispersed polyester particles in a preferably aqueous medium. The mean particle sizes are preferably in the range of 0.01 to 50 pm, more preferably from 0.01 pm to 10 pm, measured according to ISO 13320.

[0060] The polyester compositions can additionally include a crosslinker. Blocked and unblocked aziridines, carbodiimides, isocyanates, epoxides, and UV crosslinkers can be used as crosslinkers. These allow the corresponding film parameters to be adjusted to the necessary mechanical properties of the functional layer, such as hardness or abrasion resistance. In particular, near-surface UV crosslinking is suitable for curing the material. This also makes post-curing of the material possible.

[0061] According to the invention, the application of the layers using solvent-based dispersions is to be avoided. Advantageously, this can be achieved in particular by 202403270

[0062] 12. The use of aqueous polymer dispersions or emulsions will produce a multilayer composite system that does not contain any residual organic solvents that are hazardous to health and / or the environment.

[0063] In certain embodiments, particularly for synthetic leather applications, the polymer composition forming the functional layer includes a flame retardant. To achieve high flame resistance, especially in synthetic leather, all flame retardants known to a competent person are generally suitable. Preferably, flame retardants based on antimony, phosphorus, or nitrogen compounds are avoided.

[0064] Suitable flame retardants are preferably selected from the group consisting of organic phosphorus compounds such as organic phosphinate, aryl phosphate esters or phosphorus-containing polyols, ammonium phosphate or polyphosphate, melamine cyanurate, melamine phosphate, melamine, melamine polyphosphate, red phosphorus, aluminum diethyl phosphinate, aluminum trihydroxide, molybdenum oxide, magnesium hydroxide, zinc stannate, expandable graphite, zinc borate, and mixtures thereof. Naturally occurring mineral flame retardant additives, such as aluminum hydroxides, magnesium hydroxides, and boric acids, and / or bio-based flame retardant additives, such as cellulose-based compounds, sugar-based compounds, organic phosphorus compounds, and / or ester-based compounds, are particularly preferred. Suitable commercially available bio-based flame retardant additives include, for example, lignin-based compounds from Devan.

[0065] In preferred embodiments, the multilayer composite is virtually free of halogenated compounds, i.e., the proportion of halogens in the entire multilayer composite is less than 0.1 wt.%, preferably less than 0.001 wt.%, and more preferably less than 0.00001 wt.%, based on the weight of the multilayer composite. In particular, halogenated flame retardants and halogenated polymers are omitted from the entire structure, i.e., the proportion of halogenated flame retardants and halogenated polymers in the multilayer composite is 0 wt.%, based on the weight of the 202403270

[0066] 13

[0067] Multilayer composite. In this way, the environmental compatibility of the multilayer composite is further increased.

[0068] Preferably, the multilayer composite has a functional layer formed from more than one layer. At least one of the layers is a foamed layer. Alternatively or additionally, at least one of the layers is a solid layer. A functional layer can have both solid and foamed layers arranged in different sequences. This structure makes it possible to create a functional layer that adapts the flexibility and softness of the structure to the required profile.

[0069] The foamed layer can, in principle, be produced by any means known to a qualified person. For example, the foamed layer can be produced using physical or chemical blowing agents.

[0070] Preferably, one or a combination of agents from the list consisting of thermally expandable or already expanded microhollow spheres, sodium carbonate, citrate esters, CO2, sodium carbonates, air, ammonium stearate, non-ionic surfactants, e.g., polysorbates, or mixtures thereof, is used. Examples of commercially available non-ionic surfactants are Ortegol P1 from Evonik or Tensol from BASF. A foamed layer of the functional layer, formed at least partially by the addition of thermally expandable microhollow spheres, is preferred. Preferably, the foam is generated solely by the addition of the microhollow spheres.

[0071] According to the invention, the multilayer composite is a soft to medium-hard construction. This means that the hardness of the multilayer composite is below 95 Shore A or 46 Shore D, according to the invention. Preferably, the multilayer composite has a hardness of 30 to 90 Shore A (5 to 39 Shore D) measured according to DIN 53505. Constructions with a hardness of less than 65 Shore A or 19 Shore D are particularly preferred. A person skilled in the art knows how a specific hardness can be achieved. This can be accomplished, firstly, by adjusting the quantity and type of plasticizer and / or in combination with the specific selection of the 202403270

[0072] 14

[0073] Polyester types. Furthermore, the hardness can be influenced by foamed layers.

[0074] The artificial leather according to the invention is generally suitable for high-temperature and highly flexible applications. Industrial applications and automotive applications are particularly noteworthy. Industrial applications include, for example, the further processing of the artificial leather into tablecloths, floor coverings, wall coverings, automotive headliners, automotive interiors, and / or seating materials for indoor and outdoor use, such as couches, armchairs, stools, chairs, etc. Particularly noteworthy application examples include surface solutions in hotels, cinemas, homes, airplanes, buses and trains, as well as cruise ships (nautical applications).

[0075] In another aspect, the invention relates to seating furniture that has a surface made of artificial leather according to the preceding description. Such seating furniture, for example, has a cover made of the artificial leather according to the invention.

[0076] Preferably, this refers to seating furniture in a vehicle, e.g., an automobile. In the context described here, a vehicle seat comprises a single seat (such as the driver's or passenger's seat in a vehicle) and multiple connected seats, such as a rear bench seat or similar arrangement. Specifically, this refers to seating furniture in vehicles such as automobiles, trains, or aircraft. Alternatively, the seating furniture may be used in residential or commercial furniture applications. For example, the seating furniture includes chairs, armchairs, sofas, and seating in public areas such as airports, hotels, restaurants, and the like.

[0077] The seat according to the invention can be completely covered with the artificial leather as described above. The seat according to the invention can also be only partially covered with the artificial leather as described above, e.g., so that only the seat surface and / or only a central part of the seat is covered. 202403270

[0078] 15

[0079] Examples:

[0080] Example 1:

[0081] 1–100 wt% of an aqueous dispersion of a multifunctional branched oligo-copolyester with a carboxyl or hydroxyl termination (molecular weight: 500–4000 g / mol) was added, along with PET and PBSeT powders (1:1). This mixture was heated and dispersed until a homogeneous mass was obtained. The mass was then applied to a substrate and solidified at temperatures above 120 °C. To prevent migration, a crosslinking agent and / or a chain extender (diacid anhydride in a first experiment and an isocyanate in a second experiment) was added.

[0082] Five different external plasticizers were used in a 1:1 mass ratio of plasticizer to polyester mixture. The plasticizers were trioctyl trimellitate, trinonyl trimellitate, epoxidized soybean oil, polyethylene glycol 600, and the polymer plasticizer polyadipate. Depending on the plasticizer and polyester, swelling / gelling occurred at temperatures ranging from 50 °C to 220 °C. Increased elasticity or softness was observed, for example, with PBT (polyethylene glycol) with acetyl tributyl citrate, PBAT (polyethylene glycol) with dioctyl sebacate, or glycerin.

[0083] Films were produced when the pastes were applied to a coating substrate and the appropriate baking temperature was applied.

[0084] By adding 0.5 to 2.5 wt.% of a thickener or

[0085] Using a rheological aid, based on the weight of the spreadable dispersion, a water-powder mixture was converted into a spreadable, stable dispersion. The dispersion remained stable for at least seven days.

[0086] In another example, the polyester film was created as a high-solids system. Various liquid, high-viscosity polyester oligomers or short 202403270 were used.

[0087] 16

[0088] Polymers were mixed with chain extenders. These were dispersed into the liquid mass. For example, acid anhydrides such as pyromellitic dianhydride were used. The resulting pastes were applied to a substrate and baked at a temperature above 70 °C. This produced a solid film with elastic properties.

[0089] Because this manufacturing method allows for the blending of various polyesters, defined copolyesters have been produced, which in turn have led to multilayer composite systems with properties defined according to specific requirements. The advantage of a high-solids system is that no water needs to be evaporated, resulting in lower energy consumption.

[0090] For example, the addition of PEG with different molecular weights (200–1,000,000 g / mol) enabled the precise adjustment of the softness and flexibility of the multilayer composite. Further derivatives, such as PPG, were introduced into the PEG oligomers and polymers either in situ or via block copolymerization. This allowed control not only of the softness but also of the hydrophilicity / hydrophobicity.

[0091] As a recycling experiment, one of the aforementioned films was heated to a temperature of 180°C - 300°C, depending on the melting point, and converted into granules using a thermoplastic method (extruder).

[0092] The film could be converted into granules on its own or as a 1:1 mixture with PET. These granules were then used for further processing, e.g., for re-film or foil production.

[0093] The entire film and textile composite could also be easily melted using an extruder at a temperature of 200°C to 300°C and formed into granules. Depending on the weight ratio and polymer composition of the film and textile, the granules can exhibit different hardnesses, ranging from 50 Shore A to 40 Shore D.

Claims

202403270 17 Patent claims 1. Multilayer composite, in particular an artificial leather, comprising a textile layer and at least one functional layer arranged thereon, wherein the textile layer is formed from a fiber material and the fiber material is a polyester, and wherein the functional layer is based on a polyester composition comprising a polymer matrix and a plasticizing component, wherein the polymer matrix is ​​formed from an ester-based polymer, such that the entire multilayer composite has a polyester content of at least 80 wt.%, based on the weight of the multilayer composite.

2. Multilayer composite according to claim 1, wherein the plasticizing component is an internal and / or an external plasticizer.

3. Multilayer composite according to claim 2, wherein the inner plasticizer is a polyether group covalently bonded to the polymer matrix of the ester-based polymer.

4. Multilayer composite according to one of claims 2 or 3, wherein the outer plasticizer is selected from the list consisting of citrates, trimellites, adipates, succinates, sebacates, phthalates, epoxidized and / or saturated natural oils, in particular soybean oil, glycerin, isosorbide compounds, polyethylene glycols or mixtures thereof.

5. Multilayer composite according to one of claims 2 to 4, wherein the outer plasticizer has a molar mass of 200 to 3000 g / mol.

6. Multilayer composite according to any one of claims 1 to 5, wherein the polyester composition of the functional layer comprises at least 50 wt.%, based on the weight of the functional layer, the mixture of the polyester-based polymer and the plasticizing component. 202403270 18 7. Multilayer composite according to any one of claims 1 to 6, wherein the ester-based polymer in the polyester composition is selected from the group consisting of polybutylene sebacate (PBSe), polybutylene succinate (PBS), polybutylene sebacate-co-terephthalate (PBSeT), polybutylene adipate-co-terephthalate (PBAT), polyester polyurethane (PES / PU), polylactic acid (PLA) glycol-modified polyethylene terephthalate (PETG), poly(ethylene-co-isosorbide terephthalate) (PEIT), and mixtures thereof.

8. Multilayer composite according to claim 7, wherein the polyester composition is an ester-based polymer selected from the group consisting of polybutylene sebacate (PBSe), polybutylene sebacate-co-terephthalate (PBSeT) and / or polybutylene adipate-co-terephthalate (PBAT).

9. Multilayer composite according to one of claims 1 to 8, wherein the multilayer composite has a hardness of 40 to 90 Shore A measured according to DIN 53505.

10. Multilayer composite according to any one of claims 1 to 9, wherein the multilayer composite is free of halogen-containing compounds.

11. Multilayer composite according to one of claims 1 to 10, wherein the functional layer is formed from more than one layer and wherein at least one of the layers is foamed.

12. Multilayer composite according to claim 11, wherein the foamed layer of the functional layer was formed at least by the partial addition of thermally expandable microhollow spheres.

13. Multilayer composite according to any one of claims 1 to 12, wherein the polyester of the textile layer is selected from the list consisting of poly(ethylene-2,5-furan dicarboxylate (PEF), polybutyl adipate terephthalate (PBAT), polylactic acid (PLA), polyethylene terephthalate (PET), recycled polyethylene terephthalate (rPET) or mixtures thereof. 202403270 19 14. Multilayer composite according to any one of claims 1 to 13, wherein at least one layer of the multilayer composite is produced by a coating process.

15. Seating furniture, in particular for use in an automobile, comprising a surface made of a multilayer composite according to any one of claims 1 to 14.