All PU i-panel

Abstract

The present invention relates to a composite comprising a layer (LT) comprising a polyurethane (PU1) with a density (d-LT); a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF) and optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF). The present invention further relates to a process for preparing said composite as well as the use of the composite for the interior lining of motor vehicles, seat cushions, furniture, acoustic elements and bike saddles. Furthermore, the present invention also relates to a process for recycling said composite comprising a step of subjecting the composite to a process selected from melting, depolymerizing, gasifying and pyrolyzing.

Description

All PU l-PanelThe present invention relates to a composite comprising a layer (LT) comprising a polyurethane (PU1) with a density (d-LT); a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF) and optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF). The present invention further relates to a process for preparing said composite as well as the use of the composite for the interior lining of motor vehicles, seat cushion, furniture, acoustic elements and bike saddles. Furthermore, the present invention also relates to a process for recycling said composite comprising a step of subjecting the composite to a process selected from melting, depolymerizing, gasifying and pyrolyzing.Composite elements comprising a foam layer and a top layer are of considerable industrial importance, in particular in the automotive industry, and are used, for example, as seat cushions, back, neck and armrests, sun visors, instrument panels, dashboards, door panels, inter alia.For example the composite elements used for the interior of automotives have to fulfill mechanical as well as aesthetic criteria. They have to be stable elements and the mechanical properties have to fulfill the standard requirements also after aging, such as for example compression set or tensile strength. The surface properties are mainly depending on the top layers of the composite.Suitable top layers can be produced by known processes. Polyvinyl chloride (PVC) films can be obtained, for example, by the powder slush process. PVC / ABS and PVC / ABS / polyvinyl acetate polymer mixtures for the production of large-area top layers are also known. These top layers are often combined with a polyurethane foam layer. However, composite elements made from different types of plastic have the disadvantage of being difficult to recycle; however, recycling is increasing in importance. Multilayer composite elements, which may comprise, for example, a compact top or decorative layer, for example of a polyvinyl chloride film, a cellular intermediate layer, for example a flexible PU foam or polypropylene foam and a rigid base layer, for example of polypropylene, must be separated into the individual constituents and sorted. Since suitable separating equipment is currently not available for this purpose, this separation is labor-intensive and therefore very expensive.Furthermore, for the preparation of composites in a mold, expensive tools such as pumps and mixing heads are required and in particular, for small parts, mixing errors can become a problem.Therefore, it was an object of the present invention to provide a composite element and a process for its preparation with good mechanical properties which can be easily recycled.According to the present invention, this object is solved by a composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF);(iii) optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF).According to an alternative embodiment, the present invention is also directed to a composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 15 g / l to less than 45 g / l and density (d-LT) is greater than density (d-LF);(iii) optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF).The composite according to the present invention comprises layers (LT) and (LF) and optionally layer (LC). The composite according to the present invention has a layered structure. Layer (LT) is at least partially in contact with layer (LF). Preferably, layer (LT) is substantially completely in contact with layer (LF), i.e. layer (LT) preferably covers one surface of layer (LF) in the composite. In case the composite comprises a compact layer (LC), layer (LC) is at least partially in contact with layer (LF). Preferably, layer (LC) is substantially completely in contact with layer (LF) according to the present invention. Typically, layer (LC) covers the surface of layer (LF) opposing the surface of layer (LF) which is in contact with layer (LT).The composite of the present invention may comprise further layers, in particular further layers which are applied on layer (LT), for example coatings to improve the surface properties of the composite or coatings to apply a design. Suitable coatings and methods for applying such coatings in the preparation process of the composite are in principle known to the person skilled in the art.According to the present invention, layer (LT) and layer (LF) comprise a polyurethane. Preferably, layer (LF) consists of a polyurethane. More preferable, layer (LF) and layer (LT) consist of a polyurethane.Layer (LF) has a density in the range of from 45 to 400 g / l. The density may preferably be less than 200 g / l, more preferable less than 150 g / l, in particular less than 100 g / l. According to an alternative embodiment, the density may also be in a range of from 15 to less than 45 g / l, more preferable 20 to less than 45 g / l, in particular from 30 to less than 45 g / l.Preferably, layer (LF) comprises a polyurethane foam, in particular, layer (LF) consists of a polyurethane foam.According to a further embodiment, the polyurethane foam may have a compression set below 20% at room temperature. The foam preferably has a hardness in the range of from 1 to 12 kPa.According to a further aspect, the present invention is directed to a composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane foam (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF);(iii) optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF).According to a further aspect, the present invention is directed to a composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF);(iii) comprising a compact layer (LC) which is at least partially in contact with layer (LF).According to a further aspect, the present invention is directed to a composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane foam (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF);(iii) comprising a compact layer (LC) which is at least partially in contact with layer (LF).According to a further aspect, the present invention is directed to a composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane foam (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 15 to less than 45 g / l and density (d-LT) is greater than density (d-LF);(iii) optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF).According to a further aspect, the present invention is directed to a composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 15 to less than 45 g / l and density (d-LT) is greater than density (d-LF);(iii) comprising a compact layer (LC) which is at least partially in contact with layer (LF).According to a further aspect, the present invention is directed to a composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane foam (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 15 to less than 45 g / l and density (d-LT) is greater than density (d-LF);(iii) comprising a compact layer (LC) which is at least partially in contact with layer (LF).According to a further embodiment, the present invention is directed to the composite as disclosed above, wherein the polyurethane (PU2) is a polyurethane foam.Polyurethanes are well known. They are prepared by reaction of isocyanates with isocyanate-reactive com- pounds / polyol having a number-average molecular weight of 500 g / mol to 10000 g / mol and optionally chain extenders having a molecular weight of 50 g / mol to 499 g / mol, optionally in the presence of catalysts and / or customary auxiliaries and / or additives.Suitable polyurethanes and processes for their preparation are in principle known to the person skilled in the art.According to the present invention, layer (LT) has a density (d-LT) which is greater than density (d-LF). The density (d-LF) is in the range of from 45 to 400 g / l, preferably in the range of from 100 to 400 g / l, in particular in the range of from 150 to 400 g / l.According to a further embodiment, the density (d-LF) is less than 200 g / l, preferably less than 150 g / l, in particular less than 100 g / l.Layer (LT) may be a compact layer but depending on the process for preparing the composite may also comprise pores. Preferably, layer (LT) has a closed surface.Preferably, the density of the layer (LT) is in the range of from 600 to 1300 g / l, more preferable in the range of from 700 to 1200 g / l, in particular in the range of from 750 to 1100 g / l. According to a further embodiment, the present invention is directed to the composite as disclosed above, wherein the density (d-LT) is in the range of from 600 to 1300 g / l.According to a further embodiment, the density (d-LT) is greater than 700 g / l, preferably greater than 800 g / l.Layer (LT) may be prepared separately but may also be prepared starting from layer (LF). It is for example possible to adjust the composition of layer (LF) to obtain a foam with a skin, i.e. to prepare layers (LF) and (LT) in one step.Alternatively, it is possible to prepare a foam layer with a density in the range of from 45 to 400 g / l and to prepare layer (LT) in a separate step, for example by applying a suitable pressure and a suitable temperature for a time sufficient to obtain a layer (LT) with a density (d-LT) which is greater than the density of the layer (LF). In this case, layer (LT) can also be described as a compacted foam layer. In the context of the present invention, the compacted areas of the layer preferably covers at least 80% of the surface of the layer (LF) which is in contact with layer (LT), preferably at least 90% of the area, in particular at least 98% of the surface of layer (LF). It is also possible that the compacted areas of the layer can form patterns according to the present invention.According to the present invention, it is for example possible to cut a suitable foam and apply heat and pressure, thus molding the workpiece into the desired final shape by applying a pressure in a closed or open cavity, heating to a suitable temperature, for example a temperature above 140°C, at a suitable pressure of for example more than 10 kPa.In particular in case layer (LT) is prepared from layer (LF), it is preferable that (PU1) and (PU2) have the same chemical composition. This is particularly advantageous for recycling the composite element.According to a further embodiment, the present invention is directed to the composite as disclosed above, wherein polyurethane (PU1) and polyurethane (PU2) have the same chemical composition. The same chemical composition on the context of the present invention means that the respective polyurethanes are based on the same starting materials, in particular the same isocyanate and the same polyol composition.Depending on the intended use of the composite, the thickness of the layers, in particular of layer (LF), may vary.Preferably, the thickness of the layer (LC) is in the range of from 0.5 mm to 10 mm, more preferable in the range of from 1 mm to 5 mm, in particular in the range of from 1 mm to 3 mm. Preferably, the thickness of the layer (LT) is inthe range of from 0.1 mm to 5 mm, more preferable in the range of from 0.25 mm to 4 mm, in particular in the range of from 0.5 mm to 2.5 mm.For many applications, the thickness of the layer (LF) preferably is in the range of from 1 mm to 50 mm, more preferable in the range of from 2 mm to 30 mm, in particular in the range of from 5 mm to 20 mm. For other applications, the thickness of the layer (LF) preferably is in the range of from 10 mm to 200 mm, more preferable in the range of from 20 mm to 150 mm, in particular in the range of from 50 mm to 100 mm.According to a further embodiment, the present invention is directed to the composite as disclosed above, wherein layer (LT) has a thickness in the range of from 0.1 mm to 5 mm, and / or layer (LF) has a thickness in the range of from 1 mm to 50 mm, and / or layer (LC) has a thickness in the range of from 0.5 mm to 10 mm.According to an alternative embodiment, the present invention is directed to the composite as disclosed above, wherein layer (LT) has a thickness in the range of from 0.1 mm to 5 mm, and / or layer (LF) has a thickness in the range of from 10 mm to 200 mm, and / or layer (LC) has a thickness in the range of from 0.5 mm to 10 mm.According to an alternative embodiment, the present invention is directed to the composite as disclosed above, wherein layer (LT) has a thickness in the range of from 0.1 mm to 5 mm, and / or layer (LF) has a thickness in the range of from more than 200 mm to 300 mm, and / or layer (LC) has a thickness in the range of from 0.5 mm to 10 mm.Layer (LC) may comprise different materials and may also comprise two or more materials, for example polymers or metals. Layer (LC) may also comprise a polymer and metal parts embedded therein. Preferably, layer (LC) comprises at least one polymer, in particular a polyurethane. Suitable as layer (LC) are for example thermoplastic polyurethanes but also rigid polyurethane foams. Layer (LC) may also comprise fillers. Suitable materials and fillers are in principle known to the person skilled in the art.According to a further embodiment, the present invention is directed to the composite as disclosed above, wherein layer (LC) comprises a polymer, preferably a thermoplastic polyurethane. Layer (LC) may also comprise mixtures of two or more polymers, in particular two or more polyurethanes, more preferably mixtures of two or more thermoplastic polyurethanes.It has been found that the use of a layer (LC) comprising a polyurethane, preferably consisting of a polyurethane, allows for good adhesion of the layer (LF) without the need to treat the surface of the layer (LC) prior to the formation of layer (LF).According to a further embodiment, the present invention is directed to the composite as disclosed above, wherein layer (LC) comprises a filler, preferably a fibrous filler. When fillers are used, these may be inorganic and / or organic.Suitable fillers are, for example, fibrous fillers such as for example glass fibers or carbon fibers. The average length of the fibers should be in the region of the cell size or less. Preference is given to an average length of the fibers in the range from 0.1 to 10000 m, especially in the range of from 1 to 1000 pm, in particular in the range of from 1 to 100 pm. Fillers may be present in an amount in the range of from 1% to 60% by weight, preferably 5 to 40% by weight, in particular 10 to 30%by weight, based on the total weight of the layer (LC).According to a preferred embodiment of the present invention, layer (LC) comprises a thermoplastic polyurethane and a fibrous filler.According to a further aspect, the present invention is directed to a composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF);(iii) comprising a compact layer (LC) which is at least partially in contact with layer (LF), wherein layer (LC) comprises a thermoplastic polyurethane and a fibrous filler.The composite according to the present invention may be prepared in different ways. Processes for preparing composite elements comprising layers with different density and comprising different materials are in principle known.In principle, it is possible to prepare layer (LT) and, optionally, layer (LC) separately, introduce the layers in a suitable mold and then prepare the composite by preparing layer (LF) using a suitable reaction mixture in the mold. Processes are in principle known to the person skilled in the art.Alternatively, it is possible to prepare layer (LT) starting form layer (LF). It is for example possible to prepare a foam with a density in the range of from 45 to 400 g / l with a suitable skin which has a higher density, i.e. to prepare layers (LF) and (LT) in one step starting from one reaction mixture. It is also possible to prepare layer (LF) in one step and then apply suitable conditions to obtain layer (LT) starting from the foam layer.According to a preferred embodiment of the present invention, layer (LF) and layer (LT) are prepared starting from the same reaction mixture (MR-1).According to a further aspect, the present invention is directed to a process for preparing a composite, preferably a composite according to the present invention as disclosed above, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(b) preparing a polyurethane foam with a density in the range of from 45 to 400 g / l;(c) applying a temperature (T1) and a pressure (p1) to one surface of the polyurethane foam to obtain a layer (LF) with a density (d-LF) in the range of from 45 to 400 g / l and a layer (LT) with a density (d-LT) which is greater than density (d-LF).According to a further aspect, the present invention is directed to a process for preparing a composite, preferably a composite according to the present invention as disclosed above, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(b) preparing a polyurethane foam with a density in the range of from 15 to less than 45 g / l;(c) applying a temperature (T1) and a pressure (p1) to one surface of the polyurethane foam to obtain a layer (LF) with a density (d-LF) in the range of from 15 to less than 45 g / l and a layer (LT) with a density (d-LT) which is greater than density (d-LF).The process comprises steps (a) to (c) but may comprise further steps. It is for example possible to apply a further coating on layer (LT). The further coating may for example be applied to the surface of the mold before applying or preparing layer (LT).According to the present invention, the process may also comprise shaping steps, such as for example cutting a bulk foam. According to a further embodiment, the present invention thus also is directed to a process for preparing a composite, preferably a composite according to the present invention as disclosed above, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(b) preparing a polyurethane foam with a density in the range of from 45 to 400 g / l;(b1) shaping the polyurethane foam,(c) applying a temperature (T1) and a pressure (p1) to one surface of the polyurethane foam to obtain a layer (LF) with a density (d-LF) in the range of from 45 to 400 g / l and a layer (LT) with a density (d-LT) which is greater than density (d-LF).According to a further embodiment, the present invention thus also is directed to a process for preparing a composite, preferably a composite according to the present invention as disclosed above, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(b) preparing a polyurethane foam with a density in the range of from 15 to less than 45 g / l;(b1) shaping the polyurethane foam,(c) applying a temperature (T1) and a pressure (p1) to one surface of the polyurethane foam to obtain a layer (LF) with a density (d-LF) in the range of from 15 to less than 45 g / l and a layer (LT) with a density (d-LT) which is greater than density (d-LF).The shaping step (b1) may for example comprise suitable cutting steps starting from a bulk foam.The layer (LT) preferably is obtained by treating the layer (LF) from one or both sides of the layer, preferably one side of layer (LF). Treatment of the layer may be applied completely over the whole surface or partially over the surface according to the present invention. Suitable treatment may for example include the use of pressure, temperature and time wherein temperature may be supplied via heated press.According to a preferred embodiment, the layer (LF) may for example be treated by hot press embossing, for example by one side hot press embossing and optional cooling of the backside that is not embossed or also by structural hot press embossing, i.e.no embossing of the whole surface but structured embossing e.g. via heated metal tools or via embossing on different areas over the surface. It is also possible to apply a textile material in layer (LT) in this step.Suitable reaction mixtures to prepare a polyurethane are in principle also known to the person skilled in the art. According to the present invention, preferably the layer (LF) is prepared in a one-shot process. Preferably mixture (MR- 1) is introduced into the mold in such a manner that the (LT) and optionally the layer (LC) comes into contact, on the side facing the mold cavity, with the reaction mixture. When the reaction mixture has cured, the composite element formed is demolded.According to a further embodiment, the present invention is directed to the process as disclosed above, wherein the process further comprises(a.1) providing a compact layer (LC);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC).According to an alternative embodiment, the present invention is directed to a process for preparing a composite, preferably a composite according to the present invention as disclosed above, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1) providing a compact layer (LC);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 45 to 400 g / l;(c) applying a temperature (T1) and a pressure (p1) to one surface of the polyurethane foam to obtain a layer (LF) with a density (d-LF) in the range of from 45 to 400 g / l and a layer (LT) with a density (d-LT) which is greater than density (d-LF).According to an alternative embodiment, the present invention is directed to a process for preparing a composite, preferably a composite according to the present invention as disclosed above, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1 ) providing a compact layer (LC);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 15 to less than 45 g / l;(c) applying a temperature (T1) and a pressure (p1) to one surface of the polyurethane foam to obtain a layer (LF) with a density (d-LF) in the range of from 15 to less than 45 g / l and a layer (LT) with a density (d-LT) which is greater than density (d-LF).According to this embodiment, layer (LT) is prepared starting from layer (LF). Preferably, a suitable pressure and / or temperature are applied on the surface of layer (LF) resulting in a higher density of the material close to the surface and the formation of layer (LT). A suitable temperature may for example be in the range of from 100 to 250°C, in particular from 120 to 220°C, more preferable from 150 to 210°C. A suitable pressure may for example be in the range of from 5 to 50 bar, in particular from 10 to 40 bar, more preferable from 15 to 30 bar. The pressure (p1) may also be in the range of from 10 to 15 bar. Pressure and temperature may be adjusted depending on the properties of the layer (LF). A suitable time (t1) may be in the range of from 30 to 600 seconds. According to an alternative embodiment, the time may also be in the range of from 10 seconds to 300 seconds.According to a further embodiment, the present invention is directed to the process as disclosed above, wherein temperature (T1) is in the range of from 100 °C to 250°C and / or pressure (p1) is in the range of from 5 to 50 bar.According to an alternative embodiment, the present invention is directed to the process as disclosed above, wherein temperature (T1) is in the range of from 100 °C to 250°C and pressure (p1) is in the range of from 5 to 50 bar.According to the present invention, it is also possible to apply a temperature (T1) below 100 °C, in particular following a foaming step, for example several minutes after the foaming step. According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein temperature (T1) is in the range of from 55 °C to less than 100°C and / or pressure (p1) is in the range of from 5 to 50 bar.According to a further embodiment, the present invention is directed to the process as disclosed above, wherein in step (c), the temperature (T1) and / or pressure (p1) are applied for a time (t1) in the range of from 30 to 600 seconds.According to a further embodiment, the present invention is directed to the process for preparing a composite, preferably a composite according to the present invention as disclosed above, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1) providing a compact layer (LC);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 45 to 400 g / l. to obtain a layer (LF) with a density (d-LF) in the range of from 45 to 400 g / which is at least partially in contact with layer (LC).According to a further embodiment, the present invention is directed to the process for preparing a composite, preferably a composite according to the present invention as disclosed above, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1) providing a compact layer (LC);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 15 to less than 45g / l. to obtain a layer (LF) with a density (d-LF) in the range of from 15 to less than 45 g / which is at least partially in contact with layer (LC).Preferably, layer (LC) is preformed and provided in a mold and the reaction mixture (MR-1) is subsequently applied to the surface of the compact layer (LC) within the mold. The compact layer (LC) can be placed on either side of the mold. Suitable processes are in principle known.According to a further embodiment, the present invention is directed to the process for preparing a composite, preferably a composite according to the present invention as disclosed above, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1) providing a compact layer (LC);(a.1*) providing a layer (LT);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 45 to 400 g / l. to obtain a layer (LF) with a density (d-LF) in the range of 45 to 400 g / which is at least partially in contact with layer (LC) and layer (LT).According to a further embodiment, the present invention is directed to the process for preparing a composite, preferably a composite according to the present invention as disclosed above, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1 ) providing a compact layer (LC);(a.1*) providing a layer (LT);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 15 to less than 45 g / l to obtain a layer (LF) with a density (d-LF) in the range of from 15 to less than 45 g / which is at least partially in contact with layer (LC) and layer (LT).According to step (a.1*), layer (LT) is provided. Preferably, a sheet-like structure can be prepared as a top layer directly in the mold or is produced in a prior process step, stored, if necessary, in the interim and laid into the mold. If the top layer (LT) has a smooth, essentially pore-free surface as a visible surface, this surface is laid facing the inside of the mold.The PU sheet-like structures suitable as layer (LT) can be produced by known processes, for example by sintering a mixture containing a pulverulent, thermoplastic polyurethane at elevated temperature using a mold.With respect to the preferred properties of layers (LT), (LF) and (LC), reference is made to the disclosure above with respect to the composites.Mixture (MR-1) is suitable to prepare a polyurethane foam comprising an isocyanate composition and a composition comprising a compound which is reactive towards isocyanates, preferably a polyol. In order to adjust the properties such as hardness and melt index of the polyurethanes, the amounts of synthesis components used may be varied in their molar ratios. According to a further embodiment, the present invention is directed to the process as disclosed above, wherein mixture (MR-1) comprises an isocyanate composition (IC) comprising at least one compound with at least two isocyanate groups, and a composition (CP) comprising at least one compound with at least two functional groups which are reactive towards isocyanate groups.Advantageously, the mixture (MR-1) is adapted to prepare a foam with a suitable skin to prepare layers (LF) and (LT) in one step.Typically, the isocyanate composition comprises at least one polyisocyanate. According to the invention, the polyisocyanate composition may also comprise two or more polyisocyanates. Suitable isocyanates are aliphatic, cycloaliphatic, araliphatic and / or aromatic isocyanates, more preferably tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methylpentamethylene 1 ,5-diisocyanate, 2-ethylbutylene 1 ,4-diisocyanate, pentamethylene 1 ,5-diisocyanate, butylene 1 ,4-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,4-bis(isocyanatomethyl)cyclohexane and / or 1,3-bis(isocyanatomethyl)cyclohexane(HXDI), paraphenylene 2,4-diisocyanate (PPDI), tetramethylenexylene 2,4-diisocyanate (TMXDI), dicyclohexylmethane 4,4'-, 2,4'- and 2,2'-diisocyanate (H12 MDI), hexamethylene 1,6-diisocyanate (HDI), cyclohexane 1 ,4-diisocya- nate, 1 -methylcyclohexane 2,4- and / or 2,6-diisocyanate, diphenylmethane 2,2'-, 2,4'- and / or 4,4'-diisocyanate (MDI), naphthylene 1 ,5-diisocyanate (NDI), tolylene 2,4- and / or 2,6-diisocyanate (TDI), diphenylmethane diisocyanate, dimethyldiphenyl 3,3'-diisocyanate, diphenylethane 1 ,2-diisocyanate and / or phenylene diisocyanate or prepolymers of these isocyanates and polyols or isocyanates and isocyanate-reactive components.Particular preference is given to diphenylmethane 2,2'-, 2,4'- and / or 4,4'-diisocyanate (MDI), the mixtures of monomeric diphenylmethane diisocyanates and higher polycyclic homologs of diphenylmethane diisocyanate (polymer MDI).According to a further embodiment, the present invention is directed to the process as disclosed above, wherein the isocyanate functionality of the composition (IC) is in the range of from 2 to 3, 2 to 2.7, preferably from 2.0 to 2.5.According to a further embodiment, the present invention is directed to the process as disclosed above, wherein the composition (IC) comprises MDI or p-MDI or mixtures thereof, preferably composition (IC) consists of MDI or p-MDI or mixtures thereof.The composition (CP) may comprise suitable polyols such as at least one polyester- or polyetherpolyol, especially at least one polyester- or polyetherpolyol having a functionality between 1 .7 and 2.2 in each case, and it is also possible in accordance with the invention to use two or more polyester- or polyetherpolyols or mixtures of polyester- and polyetherpolyols. A "polyester- or polyetherpolyol having a functionality of xx" is understood to mean a nominally xx-func- tional polyester- or polyetherpolyol. In practice, there is a deviation from the nominal functionalities since various side reactions during the polyol synthesis can lead to a functionality that can actually be lower than nominally assumed. Polyols are fundamentally known to those skilled in the art and described for example in "Kunststoffhandbuch, Band 7, Polyurethane” [Plastics Handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition 1993, chapter 3.1.Preferably, the content of polyesters in composition (CP) is in the range of from 1 to 6% by weight based on the composition (CP), in particular in the range of from 2 to 5 % by weight.According to a further embodiment, the present invention is directed to the process as disclosed above, wherein the average functionality towards isocyanate groups of composition (CP) is in the range of from 1 to 5, preferably from 1 .8 to 3, more preferably from 1 .9 to 2.3. According to a further embodiment, the present invention is directed to the process as disclosed above, wherein composition (CP) comprises at least one diol.Composition (CP) may also comprise polyols with a functionality in the range of from 3 to 5. According to a further embodiment, the present invention is directed to the process as disclosed above, wherein the composition (CP) comprises one or more polyols with a functionality in the range of from 3 to 5.Preferably, the composition (CP) comprises at least one polyester- or polyetherpolyol. The number-average molecular weight Mn of the polyols used in accordance with the invention in the polyol composition is preferably between 500 g / mol and 10 000 g / mol, preferably between 800 g / mol and 7000 g / mol, especially between 1000 g / mol and 6000 g / mol.In addition, the composition (CP) may comprise a chain extender with a functionality of 2 or also 3 to 5. Chain extenders used are preferably aliphatic, araliphatic, aromatic and / or cycloaliphatic compounds having a molecular weight of 50 g / mol to 499 g / mol, preferably having 2 isocyanate-reactive bonds which are also referred to as functional groups. Preferred chain extenders are diamines and / or alkanediols, further preferably alkanediols having 2 to 10 carbon atoms, preferably having 3 to 8 carbon atoms in the alkylene radical, which further preferably have solely primary hydroxyl groups.Based on the total weight of composition (CP), the proportion of the chain extender is preferably in the range of from 0.5% to 7.5% by weight, more preferably 1% to 6% by weight, most preferably 1.5% to 5% by weight.In addition, one or more blowing agents are also present in the production of the polyurethane of layer (LF). Blowing agents used may be chemically active blowing agents and / or physically active compounds. Chemical blowing agents are understood to mean compounds that form gaseous products by reaction with isocyanate, for example water and carboxylic acids or carboxylic acid derivatives, for example hydrogencitrates, hydrogencarbonates or azodicarbonamides, or mixtures thereof, water being a preferred blowing agent.Physical blowing agents are understood to mean compounds that are dissolved or emulsified in the feedstocks for polyurethane production and evaporate under the conditions of polyurethane formation. These are, for example, hydrocarbons, halogenated hydrocarbons, and other compounds, for example perfluorinated alkanes, such as perfluorohexane, hydrochlorofluorocarbons, and ethers, esters, ketones and / or acetals, for example (cyclo)aliphatic hydrocarbons having 4 to 8 carbon atoms, hydrofluorocarbons, or gases, such as carbon dioxide, or mixtures thereof. In a preferred embodiment, the blowing agent used is a mixture of these blowing agents comprising water, more preferably exclusively water.In a preferred embodiment, the water content is from 0.1% to 6% by weight, preferably 0.5% to 5% by weight, more preferably 2% to 3.5% by weight or 0.5 to 1 % by weight or 3 to 4.5% by weight, based on the total weight of component (CP).The content of physical blowing agents, if present, in a preferred embodiment, is in the range between 1% and 10% by weight, especially 3% and 8% by weight, in particular in the range of from 5 to 7 % by weight, the amount of water is preferably in the range between 0.1% and 2.0% by weight, more preferably between 0.3% and 1.0% by weight andespecially between 0.5% and 0.8% by weight, based in each case on the total weight of the components used in the reaction.In the context of the present invention, it is also possible to use mixtures of different blowing agents, especially mixtures comprising at least one encapsulated blowing agent and at least one chemical blowing agent or mixtures comprising at least one encapsulated blowing agent and at least one physical blowing agent.Catalysts used for production of the polyurethane of layer (LF) are preferably compounds that significantly accelerate the reaction of the compounds comprising hydroxyl groups of component with the polyisocyanates and / or the reaction of the isocyanates with water.Suitable catalysts are, for example, amines selected from the group consisting of tertiary amines, preferably selected from the group consisting of tributylamine, triethanolamine, triisopropanolamine, N-methyldiethanolamine, N-ethyl- diethanolamine, N,N-dimethylethanolamine, N-methylmorpholine, N-ethylmorpholine, N,N,N',N'-tetramethylethylene- diamine, pentamethyldiethylenetriamine; 1,4-diazabicyclo[2.2.2]octane, N-methyl-N'-dimethylaminoethylpiperazine, bis(dimethylaminoalkyl)piperazine, N,N-dimethylbenzylamine, N,N-dimethylcyclohexylamine, N,N-diethylbenzyla- mine, bis(N.N-diethylaminoethyl) adipate, N,N,N',N'-tetramethylbutane-1 ,3-diamine, N,N-dimethyl-beta-phenylethyla- mine, bis(dimethylaminopropyl)urea, 1 ,2-dimethylimidazole, 2-methylimidazole, monocyclic and bicyclic amidines, bis(di alkyl amino)al kyl ethers; secondary amines, especially dimethylamine; and mixtures of two or more of these amines. Organic metal compounds are likewise useful. Preference is given to using organic metal compounds based on tin, zinc, bismuth, titanium, zirconium, manganese, iron, cobalt, copper, aluminum. Useful examples include organic tin compounds, such as tin(ll) salts of organic carboxylic acids, e.g. tin(ll) acetate, tin(ll) octoate, tin(ll) ethylhexanoate and tin(ll) laurate, and the dialkyltin(IV) salts of organic carboxylic acids, e.g. dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate, and bismuth carboxylates such as bismuth(lll) neodecanoate, bismuth 2-ethylhexanoate and bismuth octanoate, titanium compounds, for example titanium(IV) (triethano- laminato)isopropoxide or titanium(IV) bis(triethanolaminato)diisopropoxide or mixtures of various metal compounds. The organic metal compounds may be used either alone or in combination with strongly basic amines. In a preferred embodiment, no organic metal compounds but exclusively amines are used as catalysts. The catalysts are used typically in amounts of 0 to 2000 ppm, preferably 1 ppm to 1000 ppm, more preferably 2 ppm to 500 ppm and most preferably 5 ppm to 300 ppm.The organic metal compounds may be used either alone or preferably in combination with strongly basic amines.The catalyst or catalyst combination is typically used in amounts of 0 to 2000 ppm, preferably 1 ppm to 1000 ppm, further preferably 2 ppm to 500 ppm and most preferably from 5 ppm to 300 ppm, based on the weight of composition (CP).According to one embodiment, the present invention is directed to the process as disclosed above, wherein mixture (MR-1) comprises at least one catalyst selected from the group consisting of amine based catalyst. According to a further embodiment, the present invention is directed to the process as disclosed above, wherein mixture (MR-1) comprises at least one catalyst selected from the group consisting of metal based catalyst, potassium acetate, preferably a tin based catalyst.It has been found that the use of metal catalysts results in a stable foam layers (LF) which form a layer (LT) without additional treatment steps.Other auxiliaries and / or additives are known per se to those skilled in the art. Suitable auxiliaries and additives can be found, for example, in the Kunststoffhandbuch [Plastics Handbook], volume 7, Carl Hanser Verlag, Munich 1966 (p. 103-113). Examples of auxiliaries and additives include surface-active substances, flame retardants, nucleating agents, oxidation stabilizers, antioxidants, lubricants and demolding aids, dyes and pigments, stabilizers, for example against hydrolysis, light, heat or discoloration, inorganic and / or organic fillers, reinforcers and plasticizers.For production of the polyurethane, the polyisocyanate is reacted with the composition (CP) in the presence of the said blowing agents, catalysts and auxiliaries and / or additives. The mixing ratios chosen here are such that the equivalents ratio of NCO groups in the polyisocyanates to the sum total of reactive hydrogen atoms in the reaction mixture (MR-1) is in the range from 0.4:1 to 1 :120, preferably 0.5 to 0.95:1.2, preferably 0.6 to 0.8: 1.2 and especially 0.65 to 0.75:1.1. A ratio of 1 :1 corresponds to an isocyanate index of 100.The components are preferably mixed at a temperature in the range between 15 to 120°C, preferably 20 to 80°C, and introduced into the mold or onto the conveyor belt. The temperature in the mold is usually in the range between 15 and 120°C, preferably between 30 and 80°C.The present invention also provides the composite obtained via the processes set out above.The composites according to the invention have good mechanical properties and can easily be recycled. Furthermore, the adhesion of the layers of the composite is improved compared to a composite which is prepared starting from different layers since the layers are not only joined using an adhesive but by the chemical structure of the material.According to a further aspect, the present invention is directed to the use of the composite as disclosed above or the composite obtained or obtainable according to a process as disclosed above for the interior lining of motor vehicles, seat cushions, furniture, acoustic elements and bike saddles. The composite elements according to the invention are preferably used in the interior of vehicles, preferably motor vehicles, as cushioned fittings, for example as safety covers, glove compartments or oddment trays, sun visors and in particular dashboards.The composite element produced according to the invention preferably is fully recyclable. According to a further aspect, the present invention is directed to a process for treating a composite as disclosed above or a composite obtained or obtainable according to the process as disclosed above to obtain one or more products, the process comprising(I) providing the composite;(II) subjecting the composite to a process selected from melting, depolymerizing, gasifying and pyrolyzing.In case the composite comprises a compact layer (LC) comprising a polyurethane, preferably consisting of a polyurethane, the composite can be subjected to further treatment steps, in particular recycling steps without further disman- teling. In case the layer (LC) comprises a different polymer or a metal part, it is advantageous to separate the layer (LC) from layers (LF) and (LT) before subjecting the composite to a further treatment, in particular recycling step according to step (II). Processes for separating the layers are in principle known and may include mechanical treatment.According to a preferred embodiment of the present invention, the composite can be liquefied by heating and converted from a liquid state or melt into granules. The TPU granules can be reconverted into moldings by known methods of thermoplastic processing. It is also possible to use suitable methods for depolymerizing the composite. Suitable processes are in principle known to the person skilled in the art. Also processes such as gasification or pyrolysis may be applied.According to a particularly preferred embodiment, step (II) may comprise a melt emulsification comprising, mixing the composite and a dispersion medium and forming a mixture; shearing the mixture to form a dispersion of droplets of the composite in a liquid phase under a temperature of 160 to 250 °C; cooling the dispersion under a temperature of 0 to 100 °C and obtaining a polymer polyol. Suitable processes are in principle known to the person skilled in the art.The present invention is also directed to the product obtained or obtainable in the process for treating the composite elements as disclosed above.According to a further aspect, the present invention is also directed to a process, preferably a process as disclosed above, comprising the step: converting the product obtainable by or obtained by the process according to the invention or a chemical material obtainable by or obtained by the process according to the invention to obtain a product.According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the product is selected from:I) building block or monomer; orII) polymer, preferably polymer A, polymer composition, preferably polymer composition A, or polymer product, preferably polymer product A; oriii) cleaning polymer, cleaning surfactant, descaling compound, cleaning biocide or composition or formulation thereof; or iv) agrochemical composition, agrochemical formulation auxiliary or agrochemically active ingredient; or v) active pharmaceutical ingredient or intermediate thereof, pharmaceutical excipient, animal feed additive, human food additive, dietary supplements, aroma chemical or aroma composition; or vi) aqueous polymer dispersion, preferably polyurethane or polyurethane - poly(meth)acrylate hybrid polymer dispersion, emulsion, binder for paper and fiber coatings, UV-curable acrylic polymer for hot melts and coatings polyisocyanates, hyperbranched polyester polyol, polymeric dispersant for inorganic binder compositions, unsaturated polyester polyol or 100% curable composition; or vii) cosmetic surfactant, emollient, wax, cosmetic polymer, UV filter, further cosmetic ingredient or composition or formulation thereof; or viii) polymer B, polymer composition B, coating composition, other functional composition, foil, molded body, coating or coated substrate.According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the content of the composite in the product is 1 weight-% or more, preferably 2 weight-% or more, more preferably 5 weight-% or more, more preferably 15 weight-% or more, more preferably 30 weight-% or more, more preferably 40 weight-% or more, more preferably 60 weight-% or more, more preferably 80 weight-% or more, more preferably 90 weight-% or more, more preferably 95 weight-% or more; and / or wherein the content of the composite in the product is 100 weight-% or less, preferably 95 weight-% or less, more preferably 90 weight-% or less, more preferably 50 weight-% or less, more preferably 25 weight-% or less, more preferably 10 weight-% or less; and preferably wherein the content is determined based on identity preservation and / or segregation and / or mass balance and / or book and claim chain of custody models, preferably based on mass balance, preferably the International Sustainability and Carbon Certification (ISCC) standard.The publication Prior Art Disclosure; Issue 684; paragraphs

[1000] to

[8005] ; ISSN: 2198-4786; published: February 12, 2024 will be regarded as Reference RF1, which is incorporated herein by reference in its entirety. Preferably, the product is a product as described in Reference RF1; paragraphs

[1000] to

[8005] , Preferably, the process described herein is further a process for the production of a product.The converting step to obtain the product preferably comprises one or more step(s) as described below and can be performed by conventional methods well known to a person skilled in the art. The converting step preferably comprises one or more step(s) selected from: recycling, preferably depolymerizing, gasifying, pyrolyzing, and / or steam cracking; and / or purifying, preferably crystallizing, (solvent) extracting, distilling, evaporating, hydrotreating, absorbing, adsorbing and / or subjecting to ion exchanger; and / orassembling, preferably foaming, synthesizing, chemical conversion, chemically transforming, polymerizing and / or compounding; and / or forming, preferably foaming, extruding and / or molding; and / or finishing, preferably coating and / or smoothing.In addition, the one or more step(s) are described in detail in Reference RF1 ; paragraphs

[1000] to

[8005] ,The term "building block”, as used herein, comprises compounds, which are in a gaseous or liquid state under standard conditions of 0°C and 0.1 MPa. Building blocks are typically used in chemical industry to form secondary products, which provide a higher structural complexity and / or higher molecular weight than the building block on which the secondary product is based. The building block is preferably selected from the group consisting of hydrogen, carbon monoxide, carbon dioxid, ethylene oxide, ethylene glycols, syngas comprising a mixture of hydrogen and carbon monoxide, alkanes, alkenes, alkynes and aromatic compounds. The alkanes, alkenes, alkynes and aromatic compounds comprise in particular 1 to 12 carbon atoms, respectively.The term "monomer”, as used herein, comprises molecules, which can react with each other to form polymer chains by polymerization. The monomer is preferably selected from the group consisting of (meth)acrylic acid, salts of (meth)acrylic acid; in particular sodium, potassium and zinc salts; (meth)acrolein and (meth)acrylates. (Methacrylates comprising 1 to 22 carbon atoms are preferred, in particular comprising 1 to 8 carbon atoms. The terms (meth)acrylic acid, (meth)acrolein or (meth)acrylate relate to acrylic acid, acrolein or acrylate and also to methacrylic acid, methacrolein or methacrylate, where applicable. Further, the monomer can be selected from hexamethylenediamine (HMD) and adipic acid.The building block can further be an intermediate compound. The term "intermediate compound”, as used herein, comprises organic reagents, which are applied for formation of compounds with higher molecular complexity. The intermediate compound can be selected for example from the group consisting of phosgene, polyisocyanates and propylene oxide. The polyisocyanates are in particular aromatic di- and polyisocyanates, preferably toluene diisocyanate (TDI) and / or diphenylmethane diisocyanate (MDI).The building block and the monomer and typical converting step(s) to obtain the building block or monomer are described in more detail in paragraphs

[1000] to

[1012] of Reference RF1.The term "polymer A”, as used herein, comprises thermoplastic, e.g., polyamide or thermoplastic polyurethane, thermoset, e.g., polyurethane, elastomer, e.g., polybutadiene, or a copolymer or a mixture thereof and is defined in more detail in paragraphs

[2001] to

[2007] of Reference RF1.The term "polymer composition A”, as used herein, comprises all compositions comprising a polymer as described above and one or more additive(s), e.g. reinforcement, colorant, modifier and / or flame retardant, and is defined in more detail in paragraph

[2008] of Reference RF1.The term "polymer product A”, as used herein, comprises any product comprising the polymer A and / or polymer composition A as described above and is defined in more detail in paragraphs

[2009] and

[2010] of Reference RF1.The step(s) to obtain the polymer, preferably polymer A, polymer composition, preferably polymer composition A or polymer product, preferably polymer product A is / are described in more detail in paragraph

[2011] of Reference RF1 .The term "industrial use polymer”, as used herein, comprises rheology, polycarboxylate, alkoxylated polyalkylenamine, alkoxylated polyalkylenimine, polyether-based, dye inhibition and soil release cleaning polymers defined in more detail in paragraphs

[3035] to

[3044] of Reference RF1. The term "industrial use surfactant”, as used herein, comprises non-ionic, anionic and amphoteric industrial use surfactants defined in more detail in paragraphs

[3008] to

[3034] of Reference RF1. The term "industrial use descaling compound”, as used herein, comprises non-phosphate based builders (NPB) and phosphonates (CoP) described in more detail in paragraphs

[3001] to

[3005] of Reference RF1. The term "industrial use biocide”, as used herein, refers to a chemical compound that kills microorganisms or inhibits their growth or reproduction defined in more detail in paragraphs

[3006] to

[3007] of Reference RF1. The term "industrial use solvent”, as used herein, comprises alkyl amides, alkyl lactamides, alkyl esters, lactate esters, alkyl diester, cyclic alkyl diester, cyclic carbonates, aromatic aldehydes and aromatic esters defined in more detail in paragraphs

[3045] to

[3055] of Reference RF1. The term "industrial use dispersant”, as used herein, comprises anionic and non-ionic industrial use dispersants defined in more detail in paragraphs

[3056] to

[3058] of Reference RF1 . The term "composition and / or formulation thereof' with reference to the industrial use polymers, industrial use surfactants, descaling compounds and / or industrial use biocides refers to industrial use compositions and / or institutional use products and / or fabric and home care products and / or personal care products defined in more detail in paragraph

[3059] of Reference RF1. The converting step(s) to obtain the industrial use polymer, industrial use surfactant, descaling compound and / or industrial use biocide are defined in more detail in paragraph

[3060] of Reference RF1 . The converting steps to obtain the industrial use composition or formulation of the industrial use polymer, industrial use surfactant, descaling compound and / or industrial use biocide are defined in more detail in paragraph

[3061] of Reference RF1.The term "agrochemical composition”, as used herein, typically relates to a composition comprising an agrochemi- cally active ingredient and at least one agrochemical formulation auxiliary. Examples of agrochemical compositions, active ingredients and auxiliaries are described in more detail in Reference RF1, paragraph

[4001] ,The agrochemical composition may take the form of any customary formulation. The agrochemical compositions are prepared in a known manner, e.g. described by Mollet and Grubemann, Formulation technology, Wiley VCH, Weinheim, 2001; or Knowles, New developments in crop protection product formulation, Agrow Reports DS243, T&F Informa, London, 2005. The converting step(s) to obtain the agrochemically active ingredients and auxiliaries may be conducted in analogy to the production step(s) of their analogues that are based on petrochemicals or other precursors that are not gained by recycling processes. In addition, conversion to compounds mentioned in sections "Poly-mer” and "Cosmetic surfactant, emollient, wax, cosmetic polymer, UV filter, further cosmetic ingredient or compositions or formulations thereof' may be performed as described in these sections as well as the respective paragraphs in Reference RF1.The term active pharmaceutical ingredients and / or intermediates thereof, as used herein, comprises substances that provide pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the structure or any function of the body. Intermediates thereof are isolated products that are generated during a multi-step route of synthesis of an active pharmaceutical ingredient. The term pharmaceutical excipients, as used herein, comprises compounds or compound mixtures used in compositions for various pharmaceutical applications, which are not substantially pharmaceutically active on itself. Active pharmaceutical ingredients and / or intermediates thereof and pharmaceutical excipients are defined in more detail in paragraph

[5001] of Reference RF1.The converting step(s) to obtain the active pharmaceutical ingredients and / or intermediates thereof and pharmaceutical excipients may comprise one or more synthesis steps and can be performed by conventional synthesis and techniques well known to a person skilled in the art.The terms animal feed additives, human food additives, dietary supplements, as used herein, comprises Vitamins, Pro-Vitamins and active metabolites thereof including intermediates and precursors, especially Vitamin A, B, E, D, K and esters thereof, like acetate, propionate, palmitate esters or alcohols thereof like retinol or salts thereof and any combinations thereof; Tetraterpenes, especially isoprenoids like carotenoids and xanthophylls including their intermediates and precursors as well as mixtures and derivates thereof, especially beta carotene, Canthaxanthin, Citranax- anthin, Astaxanthin, Zeaxanthin, Lutein, Lycopene, Apo-carotenoids, and any combinations thereof; organic acids, especially formic acid, propionic acid and salts thereof, such as sodium, calcium or ammonium salts, and any combinations thereof, such as but not limited to mixtures of formic acid and sodium formiate, propionic acid and ammonium propionate, formic acid and propionic acid, formic acid and sodium formiate and propionic acid, propionic acid and sodium propionate and formic acid and sodium formiate; glycerides of carboxylic acids and short and medium chain fatty acids, conjugated linoleic acids, such as omega-6 fatty acid (C18:2) methyl ester and 1 ,2-propandiol and beverage stabilizers, such as polyvinylpyrrolidone-polymer or polyvinylimidazole / polyvinylpyrrolidone-copolymer. Animal feed additives, human food additives and dietary supplements are defined in more detail in paragraph

[5002] of Reference RF1.The converting step(s) to obtain the animal feed additives, human food additives, dietary supplements may comprise one or more synthesis steps and can be performed by conventional synthesis and techniques well known to a person skilled in the art.The terms aroma chemical and aroma composition as used herein, comprise a volatile organic substance with a molecular weight between 70-250 g / mol comprising a functional group with a carbon skeleton of C5-C16 carbon atomscomprising linear, branched, cyclic, for example with a ring size of C5-C18, bicyclic or tricyclic aliphatic chains and but not necessarily one or more unsaturated structural elements like double bonds, triple bonds, aromatics or heteroaromatics and preferably the one or more additional functional groups are selected from alcohol, ether, ester, ketone, aldehyde, acetal, carboxylic acid, nitrile, thiol, amine. In one aspect, the aroma chemical is a terpene-based aroma chemical, for example selected from monoterpenes and monoterpenoids, sesquiterpenes and sesquiterpenoids, diterpenes, triterpenes or tetraterpenes. Aroma chemicals can be combined with further aroma chemicals to give an aroma composition. Aroma chemicals and aroma compositions are defined in more detail in paragraph

[5003] of Reference RF1.The converting step(s) to obtain the aroma chemical and aroma composition may comprise one or more synthesis steps and can be performed by conventional synthesis and techniques well known to a person skilled in the art.The term "aqueous polymer dispersion”, as used herein, comprises aqueous composition(s) comprising dispersed polymer(s) and is defined in more detail in the section

[6001] entitled "aqueous polymer dispersion” of Reference RF1. The dispersed polymer(s) may be selected from acrylic emulsion polymer(s), styrene acrylic emulsion poly- mer(s), styrene butadiene dispersion(s), aqueous dispersion(s) comprising composite particles, acrylate alkyd hybrid dispersion(s), polyurethane(s) (including UV-curable polyurethanes) and polyurethane - poly(meth)acrylate hybrid polymer(s). The term "emulsion polymer”, as used herein, comprises polymer(s) made by free-radical emulsion polymerization. Aqueous polyurethane dispersion(s) are defined in more detail in the section

[6002] entitled "Polyurethane dispersions” of Reference RF1. UV-curable polyurethane(s) is / are defined in more detail in the section

[6017] of Reference RF1. Polyurethane - poly(meth)acrylate hybrid polymer(s) is / are defined in more detail in the section

[6016] of Reference RF1 .The term "polymeric dispersant”, as used herein, comprises preferably polymer(s) comprising polyether side chain, in particular polycarboxylate ether polymer(s) and polycondensation product(s) defined in more detail in paragraph

[6020] entitled "Polymeric dispersant” of Reference RF1 .The converting (polymerization) step(s) to obtain the aqueous polymer dispersion(s) comprising emulsion polymer(s) is / are defined in more detail in the section

[6003] entitled "Emulsion polymerization” of Reference RF1.The converting (polymerization) step(s) to obtain the aqueous polyurethane dispersion(s) is / are defined in more detail in the section

[6014] entitled "Process for the preparation of aqueous polyurethane dispersions” and section [6017)] entitled "Aqueous UV-curable polyurethane dispersions, their preparation and use and compositions containing them” of Reference RF1 .Composition(s) and uses of aqueous polymer dispersion(s) and of polymeric dispersant(s) are defined in more detail in the following sections of Reference RF1 : section

[6004] entitled "Uses of aqueous polymer dispersions”, section

[6005] entitled "Binders for architectural and construction coatings”section

[6006] entitled "Binders for paper coating” section

[6007] entitled "Binders for fiber bonding” section

[6008] entitled "Adhesive polymers and adhesive compositions” section

[6015] entitled "Aqueous polyurethane dispersions suitable for use in coating compositions” section

[6016] entitled "Aqueous polyurethane - poly(meth)acrylate hybride polymer dispersions suitable for use in coating compositions” section

[6017] entitled "Aqueous UV-curable polyurethane dispersions, their preparation and use and compositions containing them” section

[6018] entitled "Inorganic binder compositions comprising polymeric dispersants and their use”

[6019] 100% curable coating compositionsUV-crosslinkable poly(meth)acrylate(s) and its / their uses are defined in more detail in section

[6009] entitled "UV- crossli nkable poly(meth)acrylates for use in UV-curable solvent-free hotmelt adhesives and their use for making pressure-sensitive self-adhesive articles” of Reference RF1.Polyisocyanate(s), composition(s) comprising them and their uses are defined in more detail in section

[6010] entitled "Polyisocyanates” of Reference RF1.Hyperbranched polyester polyol(s) and its / their uses are defined in more detail in section

[6011] entitled "Organic solvent based hyperbranched polyester polyols suitable for use in coating compositions” of Reference RF1. The converting step(s) to obtain the hyperbranched polyester polyols is / are defined in more detail in the section

[6012] entitled "Preparation of organic solvent based hyperbranched polyester polyols” of Reference RF1 . Coating compositions) comprising hyperbranched polyester polyol(s), polyisocyanate(s) and additive(s) and substrate(s) coated therewith are defined in more detail in section

[6013] entitled "Organic solvent based two component coating compositions comprising hyperbranched polyester polyols and polyisocyanates” of Reference RF1 .Unsaturated polyester polyol(s), solvent-based coating composition(s) comprising said unsaturated polyester pol- yol(s) and substrate(s) for coating with said coating composition(s) are defined in more detail in section

[6018] entitled "Organic solvent based coating composition comprising unsaturated polyester polyols” of Reference RF1.100% curable coating composition(s) is / are defined in more detail in section

[6019] of Reference RF1.Polymeric dispersant(s) for inorganic binder compositions is / are defined in more detail in section

[6020] of Reference RF1. The inorganic binder composition(s) comprising the polymeric dispersants and their use are defined in more detail in section

[6021] of Reference RF1 . The converting step(s) to obtain the polymeric dispersant(s) are defined in more detail in section

[6020] of Reference RF1 . The term "inorganic binder composition” comprising the polymeric dispersant(s), as used herein, comprises preferably in particular hydraulically setting compositions and compositions comprising calcium sulfate and is defined in more detail in section

[6021] of Reference RF1 entitled "Inorganic bindercompositions comprising the polymeric dispersant and their use”. Specific building material formulation(s) comprising polymeric dispersant(s) or building product(s) produced by a building material formulation comprising a polymeric dispersant are disclosed in more detail in section

[6021] of Reference RF1.The term "cosmetic surfactant”, as used herein, comprises non-ionic, anionic, cationic and amphoteric surfactants and is defined in more detail in paragraph

[7002] of Reference RF1. The term "emollient”, as used herein, refers to a chemical compound used for protecting, moisturizing, and / or lubricating the skin and is defined in more detail in paragraph

[7003] of Reference RF1 . The term "wax”, as used herein, comprises pearlizers and opacifiers and is defined in more detail in paragraph

[7004] of Reference RF1. The term "cosmetic polymer”, as used herein, comprises any polymer that can be used as an ingredient in a cosmetic formulation and is defined in more detail in paragraph

[7005] of Reference RF1 . The term "UV filter”, as used herein, refers to a chemical compound that blocks or absorbs ultraviolet light and is defined in more detail in paragraph

[7006] of Reference RF1. The term "further cosmetic ingredient”, as used herein, comprises any ingredient suitable for making a cosmetic formulation. Several sources disclose cosmetically acceptable ingredients. E. g. the database Cosing on the internet pages of the European Commission discloses cosmetic ingredients and the International Cosmetic Ingredient Dictionary and Handbook, edited by the Personal Care Products Council (PCPC), discloses cosmetic ingredients. The term "composition and / or formulation thereof' with reference to the cosmetic surfactant, emollient, wax, cosmetic polymer, UV filter and / or further cosmetic ingredient refers to personal care and / or cosmetic compositions or formulations defined in more detail in paragraph

[7007] of Reference RF1 . The converting step(s) to obtain the cosmetic surfactant, emollient, wax, cosmetic polymer, UV filter or further cosmetic ingredient is / are defined in more detail in paragraph

[7008] of Reference RF1 .The terms "polymer B”, "polymer composition B”, "coating composition”, "other functional composition”, "foil”, "molded body”, "coating” and "coated substrate” are well known to the person skilled in the art and are defined in more detail from paragraph

[8000] to

[8005] of Reference RF1.The present invention is further illustrated by the following set of embodiments and combinations of embodiments resulting from the dependencies and back-references as indicated. In particular, it is noted that in each instance where a range of embodiments is mentioned, for example in the context of a term such as "The process of any one of embodiments 1 to 3", every embodiment in this range is meant to be explicitly disclosed for the skilled person, i.e. the wording of this term is to be understood by the skilled person as being synonymous to "The process of any one of embodiments 1, 2 and 3". Further, it is explicitly noted that the following set of embodiments represents a suitably structured part of the general description directed to preferred aspects of the present invention, and, thus, suitably supports, but does not represent the claims of the present invention.1 . A composite comprising(I) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF);(iii) optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF).2. A composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane foam (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF);(iii) optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF).3. A composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF);(iii) comprising a compact layer (LC) which is at least partially in contact with layer (LF).4. A composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane foam (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF);(iii) comprising a compact layer (LC) which is at least partially in contact with layer (LF).5. A composite comprising(i) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF),wherein the density (d-LF) is in the range of from 15 to less than 45 g / l and density (d-LT) is greater than density (d-LF);(iii) optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF).6. A composite comprising(I) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane foam (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 15 to less than 45 g / l and density (d-LT) is greater than density (d-LF);(iii) optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF).7. A composite comprising(I) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(II) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 15 to less than 45 g / l and density (d-LT) is greater than density (d-LF);(iii) comprising a compact layer (LC) which is at least partially in contact with layer (LF).8. A composite comprising(I) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(II) a layer (LF) comprising a polyurethane foam (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 15 to less than 45 g / l and density (d-LT) is greater than density (d-LF);(iii) comprising a compact layer (LC) which is at least partially in contact with layer (LF).9. The composite according to embodiment 1 or 8, wherein the polyurethane (PU2) is a polyurethane foam.10. The composite according to any one of embodiments 1 to 9, wherein the density (d-LT) is in the range of from 600 to 1300 g / l.11. The composite according to any one of embodiments 1 to 10, wherein polyurethane (PU1 and polyurethane (PU2) have the same chemical composition.12. The composite according to any one of embodiments 1 to 11 , wherein layer (LT) has a thickness in the range of from 0.1 mm to 5 mm, and / or layer (LF) has a thickness in the range of from 1 mm to 50 mm, and / or layer (LC) has a thickness in the range of from 0.5 mm to 10 mm.13. The composite according to any one of embodiments 1 to 12, wherein layer (LT) has a thickness in the range of from 0.1 mm to 5 mm, and / or layer (LF) has a thickness in the range of from 10 mm to 200 mm, and / or layer (LC) has a thickness in the range of from 0.5 mm to 10 mm.14. The composite according to any one of embodiments 1 to 13, wherein layer (LC) comprises a polymer, preferably a thermoplastic polyurethane.15. The composite according to any one of embodiments 1 to 14, wherein layer (LC) comprises a filler, preferably a fibrous filler.16. A composite comprising(I) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF);(ill) comprising a compact layer (LC) which is at least partially in contact with layer (LF), wherein layer (LC) comprises a thermoplastic polyurethane and a fibrous filler.17. A composite comprising(I) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 15 to less than 45 g / l and density (d-LT) is greater than density (d-LF);(ill) comprising a compact layer (LC) which is at least partially in contact with layer (LF), wherein layer (LC) comprises a thermoplastic polyurethane and a fibrous filler.18. A process for preparing a composite, preferably a composite according to any one of embodiments 1 to 17, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(b) preparing a polyurethane foam with a density in the range of from 45 to 400 g / l;(c) applying a temperature (T1) and a pressure (p1) to one surface of the polyurethane foam to obtain a layer (LF) with a density (d-LF) in the range of from 45 to 400 g / l and a layer (LT) with a density (d-LT) which is greater than density (d-LF).19. A process for preparing a composite, preferably a composite according to any one of embodiments 1 to 17, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(b) preparing a polyurethane foam with a density in the range of from 15 to less than 45 g / l;(c) applying a temperature (T1) and a pressure (p1) to one surface of the polyurethane foam to obtain a layer (LF) with a density (d-LF) in the range of from 15 to less than 45 g / l and a layer (LT) with a density (d-LT) which is greater than density (d-LF).20. The process according to embodiment 18 or 19, wherein the process further comprises(a.1) providing a compact layer (LC);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC).21 . A process for preparing a composite , preferably a composite according to any one of embodiments 1 to 17, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1) providing a compact layer (LC);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 45 to 400 g / l;(c) applying a temperature (T1) and a pressure (p1) to one surface of the polyurethane foam to obtain a layer (LF) with a density (d-LF) in the range of from 45 to 400 g / l and a layer (LT) with a density (d-LT) which is greater than density (d-LF).22. A process for preparing a composite , preferably a composite according to any one of embodiments 1 to 17, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1 ) providing a compact layer (LC);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 15 to less than 45 g / l;(c) applying a temperature (T1) and a pressure (p1) to one surface of the polyurethane foam to obtain a layer (LF) with a density (d-LF) in the range of from 15 to less than 45 g / l and a layer (LT) with a density (d-LT) which is greater than density (d-LF).23. The process according to any one of embodiments 18 to 22, wherein temperature (T1) is in the range of from 100 °C to 250°C and / or pressure (p1) is in the range of from 5 to 50 bar.24. The process according to any one of embodiments 18 to 23, wherein temperature (T1) is in the range of from 100 °C to 250°C and pressure (p1) is in the range of from 5 to 50 bar.25. The process according to any one of embodiments 18 to 24, wherein in step (c), the temperature (T1) and / or pressure (p1) are applied for a time (t1) in the range of from 30 to 600 seconds.26. The process according to any one of embodiments 18 to 25, wherein layer (LT) has a thickness in the range of from 0.1 mm to 5 mm, and / or layer (LF) has a thickness in the range of from 1 mm to 50 mm, and / or layer (LC) has a thickness in the range of from 0.5 mm to 10 mm.27. The process according to any one of embodiments 18 to 26, wherein layer (LC) comprises a polymer, preferably a thermoplastic polyurethane.28. The process according to any one of embodiments 18 to 27, wherein layer (LC) comprises a filler, preferably a fibrous filler.29. A process for preparing a composite, preferably a composite according to any one of embodiments 1 to 17, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1) providing a compact layer (LC);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 100 to 400 g / l to obtain a layer (LF) with a density (d-LF) in the range of from100 to 400 g / which is at least partially in contact with layer (LC).A process for preparing a composite, preferably a composite according to any one of embodiments 1 to 17, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1) providing a compact layer (LC);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 15 to less than 45 g / l. to obtain a layer (LF) with a density (d-LF) in the range of from 15 to less than 45g / which is at least partially in contact with layer (LC). A process for preparing a composite, preferably a composite according to any one of embodiments 1 to 17, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1) providing a compact layer (LC);(a.1*) providing a layer (LT);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 45 to 400 g / l to obtain a layer (LF) with a density (d-LF) in the range of from 45 to 400 g / which is at least partially in contact with layer (LC) and layer (LT). A process for preparing a composite, preferably a composite according to any one of embodiments 1 to 17, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(a.1) providing a compact layer (LC);(a.1*) providing a layer (LT);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC);(b) preparing a polyurethane foam with a density in the range of from 15 to less than 45 g / l to obtain a layer (LF) with a density (d-LF) in the range of from 15 to less than 45 g / which is at least partially in contact with layer (LC) and layer (LT). The process according to any one of embodiments 18 to 32, wherein mixture (MR-1) comprises an isocyanate composition (IC) comprising at least one compound with at least two isocyanate groups, and a composition (CP) comprising at least one compound with at least two functional groups which are reactive towards isocyanate groups.34. The process according to any one of embodiments 18 to 33, wherein the isocyanate functionality of the composition (IC) is in the range of from 2 to 3, preferably from 2 to 2.7, in particular from 2.0 to 2.5.35. The process according to any one of embodiments 18 to 34, wherein the average functionality towards isocyanate groups of composition (CP) is in the range of from 1 to 5, preferably from 1 .8 to 3, more preferably from 1.9 to 2.3.36. The process according to any one of embodiments 18 to 35, wherein the composition (IC) comprises MDI or p-MDI or mixtures thereof, preferably composition (IC) consists of MDI or p-MDI or mixtures thereof.37. The process according to any one of embodiments 18 to 26, wherein composition (CP) comprises at least one diol.38. The process according to any one of embodiments 18 to 37, wherein the composition (CP) comprises one or more polyols with a functionality in the range of from 3 to 5.39. The process according to any one of embodiments 18 to 38, wherein mixture (MR-1) comprises at least one catalyst selected from the group consisting of metal based catalyst, potassium acetate , preferably a tin based catalyst.40. Use of the composite according to any one of embodiments 1 to 17 or the composite obtained or obtainable according to a process according to any one of embodiments 18 to 39 for the interior lining of motor vehicles, seat cushions, furniture, acoustic elements and bike saddles.41 . A process for treating a composite according to any one of embodiments 1 to 17 or a composite obtained or obtainable according to any one of embodiments 18 to 39 to obtain one or more products, the process comprising(I) providing the composite;(II) subjecting the composite to a process selected from melting, depolymerizing, gasifying and pyrolyzing.42. A product obtained or obtainable according to the process according to embodiment 41 .43. Process, preferably according to embodiment 41 , comprising the step: converting the product obtainable by or obtained by the process according to embodiment 41 or a chemical material obtainable by or obtained by the method / process according to any one of embodiments 18 to 39 to obtain a product.44. The process according to embodiment 43,wherein the product is selected from: i) building block or monomer; or II) polymer, preferably polymer A, polymer composition, preferably polymer composition A, or polymer product, preferably polymer product A; or iii) cleaning polymer, cleaning surfactant, descaling compound, cleaning biocide or composition or formulation thereof; or iv) agrochemical composition, agrochemical formulation auxiliary or agrochemically active ingredient; or v) active pharmaceutical ingredient or intermediate thereof, pharmaceutical excipient, animal feed additive, human food additive, dietary supplements, aroma chemical or aroma composition; or vi) aqueous polymer dispersion, preferably polyurethane or polyurethane - poly(meth)acrylate hybrid polymer dispersion, emulsion, binder for paper and fiber coatings, UV-curable acrylic polymer for hot melts and coatings polyisocyanates, hyperbranched polyester polyol, polymeric dispersant for inorganic binder compositions, unsaturated polyester polyol or 100% curable composition; or vii) cosmetic surfactant, emollient, wax, cosmetic polymer, UV filter, further cosmetic ingredient or composition or formulation thereof; or viii) polymer B, polymer composition B, coating composition, other functional composition, foil, molded body, coating or coated substrate.45. The process according to any one of embodiments 41 to 44, wherein the content of the composite in the product is 1 weight-% or more, preferably 2 weight-% or more, more preferably 5 weight-% or more, more preferably 15 weight-% or more, more preferably 30 weight-% or more, more preferably 40 weight-% or more, more preferably 60 weight-% or more, more preferably 80 weight-% or more, more preferably 90 weight-% or more, more preferably 95 weight-% or more; and / or wherein the content of the composite in the product is 100 weight-% or less, preferably 95 weight-% or less, more preferably 90 weight-% or less, more preferably 50 weight-% or less, more preferably 25 weight-% or less, more preferably 10 weight-% or less; and preferably wherein the content is determined based on identity preservation and / or segregation and / or mass balance and / or book and claim chain of custody models, preferably based on mass balance, preferably the International Sustainability and Carbon Certification (ISCC) standard.Brief description of the figures:Figure 1 shows the transmission loss for different flexible foams. Shown are the transmission loss in DB (y-axis) for different frequencies (in Hz, x-axis). Different flexible foams were tested (flexible foam with a density of 90 g / l ( ); flexible foam with a density of 90 g / l and an embossed skin ( ), flexible foam with a density of 144 g / l flexible foam with a density of 144 g / l and an embossed skinFigure 2 shows the transmission loss for different flexible foams and integral foams. Shown are the transmission loss in DB (y-axis) for different frequencies (in Hz, x-axis). Different flexible foams were tested (flexible foam with a density of 90 g / l ( ); flexible foam with a density of 90 g / l and an embossed skin ( ), flexible foam with a density of 144 g / l and an embossed skinintegral foam with a density of 150 g / l / pentane blown (_ . > . _), integral foam with a density of 150 g / l / water blown ( . ■ _));Figure 3 shows the sound absorption for different flexible foams and integral foams. Shown are the absorption in % (y-axis) for different frequencies (in Hz, x-axis). Different flexible foams were tested (flexible foam with a density of 90 g / l ( ); flexible foam with a density of 90 g / l and an embossed skin ( ), flexible foam with a density of 144 g / l and an embossed skinintegral foam with a density of 150 g / l / pentane blown (_ . > . _), integral foam with a density of 150 g / l / water blown ( . . )).The invention is further illustrated by the following examples.Examples1 . Materials usedCarrier : TPU blend , thickness 2mmProperties:E-Modulus: 4600 MPaTensile strength: 97 MPaElongation at break: 8,5 %Impact strength (Charpy) +23°C: 102 KJ / m2Impact strength (Charpy) -30°C: 68,5 KJ / m22. Production of the foam test specimensThe carrier was placed in the mold (200 x 200 x 40 mm, temperature: 50°C) for all examples. For example 2, a polyurethane spray layer was introduced in the mold on the opposing side of the carrier.According to table 2, the feedstocks for the polyol component (A component) were mixed. Polyol component and polyisocyanate component (B component) were then mixed with an index of 90 to 105 with a Vollrath stirrer at 1820 revolutions per minute for 7 seconds and introduced into the mold. All amounts in table 2 for the starting substances are parts by weight (% by weight).Table 2: Foam compositionsFor examples 1 and 2, foam composition 1 was used as indicated in table 3. For example 3, foam composition 2 was used. For example 4, foam composition 3 was used.For examples 1 and 3, the demolded bodies were further treated. A specimen with a thickness of 20 mm of the foam was cut out of the foam plate. For examples 1 and 3, the foam test specimens produced as described above were compacted with the aid of a heated press. For this purpose, a foam body of dimensions given in table 3 was placed in a press that was at 190°C, and the metal plates were moved together until a pressure of 12 bar had been attained. After about 90 seconds the metal plates were moved apart and the compacted test specimen was removed.The foam test specimens E1 to E4 were obtained as indicated in table 3.Table 33. Acoustic properties of the foamsThe acoustic properties of flexible foams with different density and with and without pressed skin were determined.Samples of flexible foam with a density of 144 g / L and 90 g / L were used as well as samples of the respective foams with a pressed skin. For comparison, a sample of an integral foam was measured (density 150 g / L, water blown and pentane blown).All measured values were recorded with an impedance tube.Figure 1 shows the transmission loss of the respective foams. FF 144 g / L (acoustic flexible foam 144 g / L) has a higher transmission loss than FF 90 g / L. FF 144 g / L with pressed skin has a higher transmission loss than FF 90 g / L, FF 144 g / L and FF 90 g / L with pressed skin.In general, the transmission loss increases with a pressed skin. The transmission loss FF 90 g / L with embossed skin is higher than that of FF 90 g / L (without embossed skin). The transmission loss FF 144 g / L with pressed skin is higher than FF 90 g / L and FF 90 g / L embossed skin with pressed skin.Figure 2 shows a comparison of the transmission loss of the flexible foams according to the invention compared to integral foams. The transmission loss IF Pentane blown 150 g / L (Integral Foam) and IF Water blown 150 g / L is at a similar level to FF 144 g / L embossed skin with pressed skin.This shows that a Flexible Foam with embossed skin can achieve the same transmission loss as an Intergral Foam Pentane or Water blown.Figure 3 shows a comparison of the sound absorption of the flexible foams according to the invention compared to integral foams. The sound absorption of all Flexible Foam (FF) with and without pressed-in skin is higher than that of the Flexible Integral foams pentane or water driven.By pressing the skin into the FF 90 g / L, the position of the sound absorption is shifted to the higher frequency range. With FF 144 g / L embossed skin, the sound absorption decreases in comparison to FF 90 g / L and FF 90 g / L embossed skin, but is significantly higher than with the two IF foams.

Claims

Claims1 . A composite comprising(i) a layer (LT) comprising a polyurethane (PU1 ) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 45 to 400 g / l and density (d-LT) is greater than density (d-LF);(ill) optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF).

2. A composite comprising(I) a layer (LT) comprising a polyurethane (PU1) with a density (d-LT);(ii) a layer (LF) comprising a polyurethane (PU2) with a density (d-LF) and layer (LT) is at least partially in contact with layer (LF), wherein the density (d-LF) is in the range of from 15 to less than 45 g / l and density (d-LT) is greater than density (d-LF);(ill) optionally comprising a compact layer (LC) which is at least partially in contact with layer (LF).

3. The composite according to claim 1 or 2, wherein the polyurethane (PU2) is a polyurethane foam.

4. The composite according to any one of claims 1 to 3, wherein polyurethane (PU1) and polyurethane (PU2) have the same chemical composition.

5. The composite according to any one of claims 1 to 4, wherein layer (LT) has a thickness in the range of from 0.1 mm to 5 mm, and / or layer (LF) has a thickness in the range of from 1 mm to 50 mm, and / or layer (LC) has a thickness in the range of from 0.5 mm to 10 mm.

6. The composite according to any one of claims 1 to 5, wherein layer (LC) comprises a polymer, preferably a thermoplastic polyurethane.7 A process for preparing a composite, comprising(a) providing a reaction mixture (MR-1) suitable to prepare a polyurethane foam comprising an isocyanate composition and a polyol composition;(b) preparing a polyurethane foam with a density in the range of from 45 to 400 g / l;(c) applying a temperature (T1) and a pressure (p1) to one surface of the polyurethane foam to obtain a layer (LF) with a density (d-LF) in the range of from 45 to 400 g / l and a layer (LT) with a density (d-LT) which is greater than density (d-LF).

8. The process according to claim 7, wherein the process further comprises(a.1 ) providing a compact layer (LC);(a.2) applying the reaction mixture (MR-1) to the surface of layer (LC).

9. The process according to any one of claims 7 or 8, wherein temperature (T1) is in the range of from 100 °C to 250°C and / or pressure (p1) is in the range of from 5 to 50 bar.

10. The process according to any one of claims 7 or 8, wherein temperature (T1) is in the range of from 55 °C to less than 100°C and / or pressure (p1) is in the range of from 5 to 50 bar.11 . The process according to any one of claims 7 to 9, wherein the density (d-LT) is greater than 800 g / l.

12. Use of the composite according to any one of claims 1 to 6 or the composite obtained or obtainable according to a process according to any one of claims 7 to 11 for the interior lining of motor vehicles, seat cushions, furniture, acoustic elements, damping elements, shoes, protective wear and bike saddles.

13. A process for treating a composite according to any one of claims 1 to 6 or a composite obtained or obtainable according to any one of claims 7 to 11 to obtain one or more products, the process comprising(I) providing the composite;(II) subjecting the composite to a process selected from melting, depolymerizing, gasifying and pyrolyzing.

14. A product obtained or obtainable according to the process according to claim 13.

15. Process, preferably according to claim 13, comprising the step: converting the product obtainable by or obtained by the process according to claim 13 or a chemical material obtainable by or obtained by the method / process according to any one of claims 7 to 11 to obtain a product.

Images