WO2020152134A1

WO2020152134A1 - Synthetic leather and method for manufacturing synthetic leather

Info

Publication number: WO2020152134A1
Application number: PCT/EP2020/051358
Authority: WO
Inventors: Michael Heckes; Thomas Dambacher; Jonuz Mustafi; Thomas Michaelis; Martin Hestermann; Jonas Post
Original assignee: Covestro Intellectual Property Gmbh & Co. Kg; Trans-Textil Gmbh
Priority date: 2019-01-23
Filing date: 2020-01-21
Publication date: 2020-07-30
Also published as: CN113330157A; EP3914766A1; EP3686340A1; US20220090315A1; TWI825260B; TW202041377A

Abstract

The present invention relates to a multilayer synthetic leather (10) free of organic solvents, at least comprising - a textile arrangement (12); and - a polyurethane-based foam (16); wherein the polyurethane-based foam (16) is partially fixed to the textile arrangement (12) using a first fixing layer (20) such that the first fixing layer (20) comprises fixing regions (22) formed by a fixing agent and free regions (24) free from the fixing agent in the same plane.

Description

Artificial leather and method of making an artificial leather

The present invention relates to a multilayered organic solvent-free synthetic leather. The present invention further relates to a method by which such a synthetic leather can be produced.

Artificial leather and generally multilayered textile structures are widespread and have a large number of fields of application. Non-limiting examples include use in the interior of motor vehicles.

Artificial leather is usually made of a multilayer, non-breathable structure based on polyurethane or polyvinyl chloride. Vapor-permeable synthetic leather is usually based on a microporous layer that is achieved by sudden or selective evaporation of solvents. Whipped foams based on polyurethane dispersions are also permeable to water vapor, but these materials are not suitable for the use of shoe upper materials because they do not have sufficient abrasion resistance.

EP 1 887 128 B1 describes a method for producing a breathable multilayer synthetic leather with a backing layer made of a flat textile structure, at least one intermediate layer applied to the backing layer based on an at least partially open-line polyurethane foam and a top layer based on the at least one intermediate layer of a polyurethane, wherein in a first step the cover layer is applied and solidified on a removable base, subsequently the at least one intermediate layer is applied to the cover layer and then the support layer is placed on the at least one intermediate layer and the base is detached from the cover layer, whereby Formation of the top layer, an aqueous aliphatic polyurethane dispersion in liquid form is applied to the base and immediately after the application of the polyurethane dispersion the water content of the latter is caused by the application of heat is evaporated in a time interval of less than 5 s, so that a film-free drying of the polyurethane dispersion on the substrate is brought about, with the formation of the cover layer with micropores.

EP 2 918 629 A 1 describes a process for producing a breathable film based on polyvinyl chloride (PVC), comprising the steps: 1. providing a pasty mass comprising a first fraction made of PVC and a second fraction made of a foreign substance and a third fraction from auxiliaries and additives which are mixed with one another to form the pasty mass, 2. applying the pasty mass to a base, 3. drying and gelling the pasty mass applied to the base with heat being supplied to the film, from one surface to the other of the film extending pores are formed, which make the film breathable to lend.

CN 105 951 466 describes water-based screen touch glove leather and a

Manufacturing process therefor. The water-based screen touch glove leather comprises base fabric, and the base fabric is coated with an underlayer and a surface layer, in which a slurry of the underlayer is made by stirring the following raw material components in parts by weight: 100 parts of water-based polyurethane resin, 0.4-1 part of a water-based Thickener, 0.3-0.7 part of a defoaming agent, 0.5-2 part of a flat screen, 0.2-2 part of a catalyst and 0.5-5 part of a hardener; the slurry of the top layer is produced by stirring the following raw material components in parts by weight: 100 parts of the aqueous polyurethane resin, 2-18 parts of the water-based color paste, 0.5-3 parts of a water-soluble dispersing agent, 5-15 parts of screen-touch powder, 4-2 parts of the water-based thickener, 0.2-1 part of the defoamer and 0.5-2 parts of the flat screen. According to the water-based screen-touch glove leather, the screen-touch glove leather is introduced into the slurry of the surface layer of the glove leather, so that the water-based screen-touch glove leather has good conductivity; water-based touchscreen gloves made from the water-based touchscreen glove leather can be used on an electronic product provided with a touchscreen; the touchscreen electronic product can be used by a user wearing the water-based touchscreen gloves.

DE 27 54 603 A1 describes a process for the solvent-free coating of substrates, in particular leather, split leather and textiles, with the aid of a film which is composed of a high-melting layer, a low-melting layer and, if appropriate, an additional intermediate layer.

DE 10 2013 021 148 A1 relates to a leather exchange material comprising an upper layer which is external during operation or use, a middle layer connected to this and a lower layer connected to this. Accordingly, it is provided that the top layer is formed from a solidified, crosslinked PU dispersion based on aliphatic polyester and / or polyether, that the middle layer is formed from a knitted fabric or a fabric made of polyester fibers, that the knitted fabric or fabric has a basis weight of 190 to 420 g / m ² and a thickness of 0.30 to 0.60 mm has that the lower layer is formed from a foamed plastic that was applied in liquid or pasty form to the middle layer, that both the upper layer and the lower layer in of a thickness of at least 0.050 mm are introduced into the middle layer and are inseparably connected thereto, and that a layer with a thickness (D) is formed in the middle layer which is free of the plastics used in the top layer and the bottom layer. WO 02/33001 A1 describes a method for producing an artificial leather, in which a composition which contains an anionic or cationic aqueous polyurethane dispersion, a water-repellent agent, an emulsifier, a defoamer and an inorganic filler is impregnated into a substrate and applied to the substrate the impregnated and / or coated substrate is then coagulated into an artificial leather which is internally provided with numerous closed cells and has a smooth surface. The synthetic water-based polyurethane leather is obtained by impregnating a composition comprising 100 parts by weight of an aqueous polyurethane dispersion, 0.1 to 5 parts by weight of a water repellent, 0.1 to 8 parts by weight of an emulsifier, 0.1 to 1 part by weight of a defoamer and 0.1 to 5 parts by weight an inorganic filler into a substrate, coating the foamed or defoamed composition on the substrate, and coagulating the coated substrate with a coagulation solution, wherein an aqueous polyurethane dispersion is covalently bound to anionic groups including carboxyl groups or sulfonate groups or cationic groups including a tertiary amine group, the coagulation solution is selected from the group consisting of an aqueous solution of different salts, a mixed solution of salt and acid, a mixed solution of salt and base, a mixed solution of acid and base and Mi. creations of the same.

In the prior art, however, there is still a need for variants of an artificial leather, the synthetic leather having a high mechanical stability and still being very breathable.

It is therefore the object of the present invention to at least partially overcome the disadvantages known from the prior art. In particular, it is the object of the present invention to create a possibility by means of which, in particular, an artificial leather has high mechanical stability and is also very breathable.

According to the invention, the object is achieved by a synthetic leather with the features of claim 1. The object is also achieved according to the invention by a method with the features of claim 11 and by a method with the features of claim 12. Preferred embodiments of the invention are in the Subclaims, described in the description or the figures, further features described or shown in the subclaims or in the description or the figures, individually or in any combination, can constitute an object of the invention if the context does not clearly indicate the opposite.

The present invention relates to a multilayer synthetic leather, at least having a textile arrangement; and a polyurethane-based foam; wherein the polyurethane-based foam with the textile arrangement is partially fixed using a first fixing layer such that the first fixing layer has fixing areas formed by a fixing agent and in the same plane, in particular in the plane of the fixing area, free areas free of the fixing agent.

Such a synthetic leather has clear advantages over the solutions from the prior art. In particular, a synthetic leather of this type can be particularly breathable and yet have high mechanical stability.

For the purposes of the present invention, breathability is understood to mean the water vapor permeability of a textile material in particular. In general, the better the water vapor permeability rate, the more pleasant the microclimate is for the user of the synthetic leather. The synthetic leather advantageously has a breathability which is in a range of up to 1,000 g / m ² / 24h or more, for example in a range of up to 10,000 g / m ² / 24h or even more, the upper limit being the synthetic leather “The breathability of functional textiles is generally determined by the MVTR value (Moisture-Väpor-Transmission-Rate-Value), which describes the water vapor permeability and / or by the RET value (Resistance-Evaporating-Heat-Transfer -Välue), which describes the water vapor resistance. If the present invention were rated for breathability according to the standard DIN EN 343: 2010-05 protective clothing - protection against rain, a RET value up to class 4 could be achieved.

An artificial leather is to be understood in particular as a textile multilayer arrangement which is based on real leather in terms of its appearance and / or its feel, in particular in both the look and feel.

The synthetic leather can be used in a wide variety of areas of leather goods, for example for baggage goods, clothing materials, such as for coats or jackets, for furniture, such as for seating, for example sofas, for home textiles, or also for automotive interiors, for example vehicle seats, or for Sporting goods. However, the synthetic leather described here is particularly preferably suitable as a material for shoes, for example as a shoe upper.

The synthetic leather described here has the following configuration or the following layer structure. In particular, at least one of the layer structure and the in substances used in the layer structure or a combination of the layer structure with the substances present therein show advantageous effects compared to solutions from the prior art.

First of all, the synthetic leather or its layer structure comprises a textile arrangement. This textile arrangement is fundamentally selectable and is preferably adapted to the desired field of application, as not described in a restrictive manner above.

By way of example, the textile arrangement can have a textile layer of this type, which is selected from the group consisting of a woven fabric, a knitted fabric, a knitted fabric, a nonwoven fabric or else a 3-D spaced fabric. In principle, the present invention can include the fact that the textile materials described above are not only used in isolation, but also as a suitable mixture comprising at least one of the aforementioned examples.

In addition, it can be provided that the textile arrangement or a textile layer contained therein is designed on the basis of natural fibers or also on the basis of artificial or synthetic fibers. The specific selection of the fibers for the textile layer can in turn be made in a manner that is readily understandable for the person skilled in the art based on the specific desired application.

The advantage of providing a textile can be seen, for example, in the fact that this layer gives the entire layer structure or the artificial leather an extraordinarily high mechanical stability. The stability can be given in particular with regard to good tensile strength and also good tear strength.

Another advantage of a textile layer, in particular as a carrier layer in the layer structure of the synthetic leather, can furthermore be seen in the fact that by providing a textile layer, a textile grip of the synthetic leather can be achieved, which can significantly improve the acceptance of the synthetic leather.

Finally, the textile layer makes it possible not to deteriorate or to allow an elasticity and breathability provided by the further layers of the layer arrangement.

It is thus clear from the above that the provision of a textile arrangement, in particular comprising at least one textile layer, in particular as a carrier layer in the layer structure, retains the positive properties of the further layers and can furthermore enable further positive properties.

Furthermore, the synthetic leather or the layer arrangement of the synthetic leather comprises one polyurethane-based foam, which can be designed or manufactured in particular as a whipped foam. For the purposes of the present invention, a polyurethane-based foam is to be understood in particular as a layer of this type which is porous and thus allows water vapor or gases to pass through and is therefore breathable. In addition, polyurethane-based should mean that the foam can consist of polyurethane or at least should have polyurethane. For example, the polyurethane-based foam can have a silicone, as described in greater detail below.

Basically, the polyurethane-based foam can exist in different grammages and / or in different foam liter weights or in different porosities. The specific selection of the polyurethane-based foam used can in turn be made in a suitable manner by the person skilled in the art, in particular depending on the specific application of the synthetic leather.

Providing a foam, in particular in the form of a whipped foam, in the layer structure or in the synthetic leather can have the advantage, for example, that an elastic basic structure is obtained. This is necessary for many areas of application so that the provision of a foam can improve the range of applications.

In addition, a foam can make the grip positive or enable a particularly advantageous feel, which can come very close to the feel of real leather.

Furthermore, by providing a foam, it can easily be possible to implement a structure on the outer surface of the synthetic leather or the layer structure which is very similar to the structure of real leather, which can further improve both the appearance and the feel of the synthetic leather.

The foam can ensure that on the one hand the required elasticity and on the other hand the mechanical resistance, in particular abrasion resistance, of the synthetic leather is provided or can at least contribute to this.

Another advantage of polyurethane as the base material for the foam can be seen that the foam as such can have good mechanical resistance even without further additives.

In an embodiment with a cover layer, as described in greater detail below, it can also be preferably provided that the foam has no structure, since the cover layer can usually be the top layer and thus the layer considered when the synthetic leather is used, and thus the cover layer can have a structure. The The structure can be introduced into the cover layer or the foam, for example, by producing the synthetic leather as described below in a reversal process and applying the cover layer or the foam to a structured, removable base, as described below. Alternatively, the structure can be embossed into the cover layer.

It is thus clear from the above that in particular the provision of a polyurethane-based foam can be particularly beneficial in achieving the properties desired for an artificial leather.

In the synthetic leather described here, it is further provided that the polyurethane-based foam with the textile arrangement is partially fixed using a first fixing layer such that the first fixing layer has fixing areas formed by a fixing agent and free areas free of the fixing agent in the same plane.

Thus, in the synthetic leather described here, contrary to the solutions from the prior art, it is not provided that a fixing layer, such as basically an adhesive layer, which connects the foam with the textile arrangement, is applied over the entire surface to the foam or the textile arrangement or between the textile arrangement and the foam is present, but the fixing layer or the fixing agent forming it should only be partially provided. Due to the partial provision of the fixing agent, fixing areas can thus be present on one side. These fixing areas are areas in which a fixing agent forming the fixing layer is present. In these fixing areas, the foam is thus connected or glued to the textile arrangement.

Furthermore, there are free areas in the same plane and thus in particular in a plane spanned by the width and depth of the layer arrangement of the synthetic leather, which is perpendicular to the thickness of the synthetic leather. These free areas are characterized in that no material forming the fixing layer is provided in these areas. This means that the foam in the free areas is in direct contact with the textile arrangement.

This arrangement in particular can offer significant advantages over the solutions from the prior art.

Because in particular the breathability and thus the water vapor permeability can be significantly improved by only partially providing the fixing layer, in particular compared to the provision of a full-surface application of a fixing layer such as an adhesive layer. Because in the open areas, water vapor, for example, can easily pass from the textile arrangement into the foam; there is no inhibition by the fixing layer. In addition, the strength of the textile arrangement and foam against one another cannot be significantly impaired, since the fixing layer or the fixing agent forming the fixing layer can be selected with regard to positive fixing properties, for example with regard to positive adhesion properties. A compromise with good breathability and thus water vapor permeability is not necessary. Therefore, the partial provision of the connection layer can be sufficient for good adhesive properties.

Furthermore, by only partially fixing the textile arrangement to the foam, particularly good adaptability to the textile arrangement may be possible, or the textile arrangement may be freely selectable. This is because the structure of the partial provision of the fixing layer can be adapted to a structure of the textile arrangement, if any. Thus, textile arrangements with various structures can be fixed with a foam without loss of adhesion.

Furthermore, only partially fixing the textile arrangement to the foam enables the fixing layer to be formed with a reduced amount of fixing agent to form the fixing layer. This can reduce costs and save weight.

Finally, in particular the structure of the partial fixing of foam and textile arrangement or the formation of the fixing areas and the free areas, in particular with regard to their size and optionally arrangement, can be tailored to the fixing layer and thus also of the entire synthetic leather, for example with regard to breathability, mechanical resistance, elasticity , Water repellency etc. enable. A particularly high degree of adaptivity is thus made possible.

The synthetic leather described here also has the advantage that it can be free of organic solvents, which can significantly reduce unpleasant smells and other nuisances.

Furthermore, further properties which are preferred for textile applications can be achieved. For example, a wash resistance according to DIN EN ISO 6330 of 5 x 40 ° is achieved, which allows a wide range of applications.

The synthetic leather also has an air permeability according to EN ISO 9237, which can have a value of at least 3.0 l / m ² / s (20 cm ² ; 100 Pa) or more.

With regard to the fixing agent, which forms the fixing layer or can at least be part of it, it may be preferred that this is a hot melt adhesive based on polyurethane. Such a fixing agent can also be referred to as a polyurethane-based hot melt. For example, the hot melt adhesive can be moisture-crosslinking.

Furthermore, it can be provided that the fixing agent is formed from an especially aliphatic polyester-polyurethane dispersion. In particular, the dispersion for producing the fixing agent can comprise a polyurethane dispersion with a polyurethane polymer which is composed of at least and in particular exactly two different polyols and at least one polyisocyanate, one polyol of the two different polyols being an aliphatic polyester polyol and a second one two polyols is a polyether polyol which has been produced from hydrophilic alkylene oxides with multifunctional groups, in particular with two to eight functionalities, and also preferably with branched and / or star-shaped structures. Furthermore, the polyisocyanate can also be aliphatic. In particular, the dispersion can be designed to produce the fixing agent, as described in US Pat. No. 9,783,701. Both of the aforementioned variants, for example the provision of a polyurethane-based hot melt adhesive and the formation of the fixing layer from a polyester-polyurethane dispersion, can serve to form the fixing layer particularly advantageously with regard to breathability, mechanical resistance, elasticity and / or water repellency.

It may further be preferred that the first fixing layer is applied or is present in a punctiform manner. The advantages described above can be implemented particularly effectively by a punctiform application, since the amount and structure of the fixing agent can be adapted particularly simply and efficiently in the case of a dot shape of the individual fixing regions. This is easily possible, for example, by varying the size of the point areas and the distance between the point areas.

In addition, the provision of a punctiform application of the fixing layer is efficient and can be implemented in a defined manner by a screen printing process which, like basically any application of the fixing layer, is possible on the foam or else on the textile arrangement.

The same advantages as with a punctiform application can also be generated if the fixing layer is applied or is present in the form of diamonds or in the form of bars.

It may further be preferred that the first fixing layer is applied in an amount in the range from> 2 to <50 g / m ² , in particular in a range> 10 g / m ² to <20 g / m ² or between the foam and the textile arrangement is present. This configuration shows a significantly reduced application amount of the fixing layer compared to solutions from the prior art. In this embodiment in particular, the advantages described above can be implemented particularly effectively. For example, in this embodiment, in particular, the breathability or the water vapor permeability can be influenced only minimally by the fixing layer and thus essentially retained in comparison to a layer structure without Fixing layer.

With regard to the textile arrangement, it can be provided that it consists of a textile layer, that is to say in particular of a single textile layer. In this embodiment, the structure of the synthetic leather and thus in particular the layer structure of the same can be particularly simple, which can also simplify the manufacturing process. In addition, costs and weight can be saved, which also has an advantageous effect on the synthetic leather.

The properties that can be achieved, which can be achieved by a textile arrangement consisting only of one textile layer, can be sufficient for a large number of applications.

Alternatively, it can be provided that the textile arrangement has a textile layer and a water-impermeable membrane, the water-impermeable membrane being partially fixed to the textile layer using a second fixing layer in such a way that the second fixing layer is formed by fixing elements and in the same Level of the fixing agent has free areas. The second fixing layer can thus be configured as described above with reference to the first connecting layer, in particular with regard to the manufacture or formation, with regard to the chemical structure and with regard to the structure.

In other words, it can be provided that the textile arrangement, in particular before being connected to the foam, can also have been previously connected to a breathable and waterproof membrane to form a two-layer laminate.

The membrane can, in particular, ensure that the finished synthetic leather has a high water column in addition to high breathability, or that liquid water does not pass through the membrane and thus only very little of the synthetic leather. The membrane or the membrane system can be freely selected according to the respective requirement. Polymer-based membranes may be preferred here. For example, polyether esters (PES), polytetrafluoroethylene (PTFE), and polyurethane (PU) can be processed into membranes and are particularly effective here. Seam sealing using a seam sealing tape is preferably carried out in combination with the membrane used. A hydrostatic pressure of 200 mbar required for protective clothing according to DIN EN ISO 811 is achieved on the seam or for a seam seal.

By providing the membrane, the synthetic leather can be produced while maintaining the breathability and also while maintaining the elasticity in the overall structure.

Basically, a membrane can be understood as a layer that, in comparison to a design without a membrane, which influences the transport of the fabric through the synthetic leather, in particular reduces or completely prevents the transport of liquid water through the synthetic leather, or enables a high water column of up to 10 meters or even more than 10 meters, which can, for example, cause hydrostatic pressure of 1000 mbar or higher according to DIN EN ISO 811.

It can further be provided that a particularly breathable cover layer is also provided on the polyurethane-based foam. In principle, the cover layer can result in the synthetic leather having a particularly high abrasion resistance, which can be of great advantage in relation to the application.

In addition, in this embodiment in particular, it can be advantageous that the polyurethane-based foam can be formed in a conventional manner. This can make manufacturing easier and reduce costs. The cover layer can also be selected in such a way that the water vapor permeability and also the breathability are not or not significantly negatively influenced.

In principle, the cover layer can be formed from a hydrophilic material.

It can particularly preferably be provided that the cover layer is formed from an especially aliphatic polyester-polyurethane dispersion. In particular, the dispersion for producing the fixing agent and / or the top layer can comprise a polyurethane dispersion with a polyurethane polymer which is composed of at least and in particular exactly two different polyols and at least one polyisocyanate, a polyol of the two different polyols being an aliphatic polyester polyol and a second of the two polyols is a polyether polyol, which was produced from hydrophilic alkylene oxides with multifunctional groups, in particular with two to eight functionalities, and further preferably with branched and / or star-shaped structures. Furthermore, the polyisocyanate can also be aliphatic. In particular, the dispersion can be designed to produce the fixing agent, as described in US Pat. No. 9,783,701.

Advantages of such a cover layer include in particular that such a cover layer can meet the requirements of a synthetic leather in a particularly advantageous manner. The cover layer offers excellent mechanical properties, such as particularly good abrasion resistance, which is advantageous for maintaining the structure and for a long lifespan of the synthetic leather. In addition, such a cover layer can in particular have a particularly pronounced breathability or water vapor permeability, which is also a requirement of high-quality synthetic leather. In summary, such a cover layer in particular can provide a high synergy of the desired properties. It can be provided that the cover layer consists of the aliphatic polyester-polyurethane of the dispersion described above, or that further components are included.

In addition, it can in principle be provided that the cover layer is present over the entire surface or is only partially applied. If the application is only partial, the breathability and the water vapor permeability can be improved compared to a full application. With a full-surface application, for example, the mechanical properties can be improved compared to a partial application.

Thus, in summary, a cover layer can have increased abrasion resistance, but at the same time allow water vapor permeability or breathability to remain essentially the same or only insignificantly reduced.

In an embodiment with a cover layer, it can also be preferably provided that the cover layer has a structure, since this can usually be the top layer and thus the layer considered when the synthetic leather is used. The structure can be introduced into the cover layer, for example, by producing the synthetic leather, as described below, in a reversal process and applying the cover layer to a structured, removable base, as described below. Alternatively, the structure can be embossed into the cover layer.

Furthermore, it may be preferred that the polyurethane-based foam has a silicone. The polyurethane dispersion is modified in particular with a combination of OH-functionalized addition-crosslinking aqueous silicone emulsion and a polyhydrogenmethylsiloxane in order to achieve particularly high abrasion and kink resistance.

In this embodiment, for example, the basis for the polyurethane-based foam can in no way be limited to this, but can generally be a polyurethane dispersion as described in WO 03/060017 A2 or in WO 02/090413 A1.

In an exemplary embodiment, the polyurethane-based foam can be formed from a dispersion which has a polyurethane based on an aliphatic polycarbonate ester. For example, the dispersion for producing the foam can comprise a polyisocyanate and a mixture of polycarbonate and polytetramethylene glycol polyols.

For example, the polyurethane-based foam can have an aliphatic polyester as the polyol.

An advantage of this configuration, but also in principle with a polyurethane-based one Foam, especially whipped foam, comes into play because the foam, shown as a film, is elastic and hydrophobic.

For example, the foam can have a density in a range from> 500 g / l to <750 g / 1.

It can further be provided that polyisocyanate and melamine resin are introduced into the foam formulation as additional crosslinking components. The mechanical strength of the foam is increased by installing additional networks such as polyurea and melamine resin.

To thicken the polyurethane dispersion, an aqueous emulsion of an acrylic copolymer is added to the polyurethane dispersion, which in particular has a viscosity in the process of less than 16 mPa.s in aqueous solution. The coating paste or the foam when applied can have a viscosity of about 35 to 50 dPas.

It can also be provided that the foam is designed as a breathable lacquer layer.

In this embodiment in particular, it can be made possible to dispense with the cover layer. Because especially in this embodiment, the abrasion resistance and kink resistance can be increased compared to conventional foams due to the special composition of the foam. In this embodiment in particular, the mechanical stability of the foam is therefore sufficient for a large number of applications.

In addition, especially in this embodiment or in an embodiment without a cover layer, synergies can be offered to fix the foam to the textile arrangement only partially or locally, for example in a punctiform manner. This is because, in particular in this embodiment, the foam can have high abrasion resistance and also high water vapor permeability and also breathability. These positive properties can be effectively maintained by the configuration of the first fixing layer, since these are further promoted by the configuration of the first fixing layer.

It can also be preferred that the polyurethane-based foam has a solids content of greater than or equal to 40% by volume, for example a solid content of greater than 50% by volume, preferably in a range from greater than or equal to 40% by volume to less than or equal to 70% by volume, for example in a range from greater than or equal to 55% by volume to less than or equal to 68% by volume. In this embodiment, the production of the synthetic leather can be further improved. Because in particular with such a foam, in particular whipped foam, drying with the removal of the solvent can take place particularly quickly due to the high solids content, which can make the production particularly effective. For example, the foam can be a Have solids content of 60 vol .-%, this value is to be understood with a tolerance of +/- 10 vol .-%.

In addition, the foam in this embodiment can have a particularly high mechanical stability, which can be of great advantage from the point of view of the application and can also allow a cover layer to be dispensed with.

With regard to further advantages and technical features of the artificial leather, reference is made to the description of the method, and vice versa.

Also described is a method for producing a multilayer synthetic leather, as described above, the method comprising the following method steps: a) providing a base; b) if necessary, applying a cover layer to the base; c) applying a polyurethane-based foam to the base or, if a cover layer is present on the base, to the cover layer; d) partial application of a first fixing layer onto the polyurethane-based foam or onto a textile arrangement, forming fixing areas formed by a fixing agent and free areas free of the fixing agent in the same plane; e) applying the textile arrangement to the polyurethane-based foam; and f) removing the pad.

The method steps described above can take place in the order mentioned or in a different order, as is explained below by way of example.

Such a method allows a synthetic leather to be created in a particularly advantageous manner, as is described in detail above. Accordingly, with regard to the advantages or the advantageous configurations of the synthetic leather produced by the method, reference is made in full to the description of the synthetic leather.

Such a method basically describes the formation of the synthetic leather in a so-called reverse process. According to this reversal process, the artificial leather to be obtained is thus built up from the uppermost layer, that is to say the layer which, when using the synthetic leather thus produced, is most outward or can be visible to a user, to the lowest layer. To this end, the process has the following process steps:

First, according to method step a), a base is provided. Such a base can in particular be removed from the layer subsequently applied to it and, as described below, cannot therefore be part of the synthetic leather to be produced. Furthermore, the base can be structured in particular in order to introduce a structure into the layer applied to the base.

For example, the base can be made of paper and can be provided with a structure as grained base paper.

According to method step b), the method furthermore optionally includes the application of a cover layer to the base. This can be done, for example, by knife coating, and a desired thickness of a suitable material for the cover layer can be applied. In particular, the cover layer can be applied if an improved abrasion resistance is to be achieved by this. On the other hand, the cover layer can be dispensed with if a subsequently applied foam already has sufficient mechanical strength. In other words, the top layer can be applied as a function of the foam applied to the top layer.

Accordingly, the method according to method step c) comprises applying a polyurethane-based foam to the base or, if a cover layer is present on the base, to the cover layer.

Thus, if the cover layer is dispensed with, the foam can be applied directly to the base and can be provided with a structure, as described above.

If the cover layer is provided, the foam can be applied accordingly to the cover layer.

The foam is in turn applied with a suitable polyurethane-based material in a suitable thickness. For example, the foam can be doctored. It can be advantageous, particularly when only the foam is provided or when the cover layer is left out, that this process step c) can be carried out in a single-coat process, which can bring process-related advantages with regard to the periphery for carrying out the process.

Correspondingly, if a cover layer is provided, method steps b) and c) can be carried out as a two-stroke method. In addition, it is understandable for the person skilled in the art that in particular the cover layer or the foam can be dried or hardened before further processing. A porosity can be improved by drying or pores of the foam can be opened, which has a positive effect on breathability or water vapor permeability.

Furthermore, the method according to method step f) comprises removing the base. This step can be carried out, for example, after process step c), so that after process step f) a semi-finished product can optionally have been produced from a foam sheet with a cover layer. The base can be removed mechanically, for example. This can result in the top layer or the foam being present as the top layer, depending on the specific configuration.

According to method step d), partial application of a first fixing layer to the polyurethane-based foam or to a textile arrangement takes place with the formation of fixing areas formed by a fixing agent and free areas free of the fixing agent in the same plane. In this process step, a fixing agent, such as a hot melt adhesive, is thus applied to part of the surface of the foam or the textile arrangement.

According to this process step, the foam present after drying, for example in the form of a film, or the textile arrangement is provided with the fixing agent, for example by means of a screen printing process described as well as screen print technology. The screen printing process involves knife coating a fixing agent, for example a polyurethane-based hot melt adhesive. Adhesive coatings in the range of 2-50 g / m ² , in particular 10 g / m ² to less than or equal to 20 g / m ² , can be realized.

For example, a polyurethane-based hot melt adhesive can be used as the fixing agent. Fixing agents of this type are adhesives which crosslink with atmospheric moisture, the setting time of which depends on the application temperature, amount of adhesive, type of substrate, temperature of the substrate and the ambient conditions.

According to method step e), the method also includes applying the textile arrangement to the polyurethane-based foam, for example partially provided with the first fixing layer. For example, the textile arrangement, which can serve as a carrier in the finished artificial leather, is joined or laminated under pressure on the foam. Due to different perforated templates, very precise layers of adhesive can be realized. Due to the technology-related low adhesive layer and an optimal distribution of the adhesive, the breathability of the coating is only minimally influenced. Such a method allows in particular the production of a mechanically stable and breathable synthetic leather, as described above.

Alternatively, an artificial leather according to the invention, for example in a departure from a reversal process, can be produced with at least the following process steps: g) providing a textile arrangement; h) providing a polyurethane-based foam; i) partial application of a first fixing layer onto the polyurethane-based foam or onto the textile arrangement, forming fixing areas formed by a fixing agent and free areas free of the fixing agent in the same plane; j) joining the polyurethane-based foam and the textile arrangement; and k) optionally applying a cover layer to the polyurethane-based foam.

This process also leads to a synthetic leather as described above. However, this does not necessarily work in reverse, but the synthetic leather can be built up from the textile arrangement as a carrier. However, a reverse procedure is also not excluded in this embodiment.

With regard to the formation and production of the individual layers, reference is made to the further explanations.

However, it should be mentioned that, for example, in order to produce the foam, it can be generated separately beforehand, for example by applying it to a base, drying and removing the base or also by separating the foam from a larger foam.

With regard to a structure of the foam or the cover layer, it can further be provided that the structure is embossed.

It can particularly preferably be provided that the first fixing layer is applied in method step d) or i) using a screen printing method. By means of a screen printing process, it is possible in a simple and effective manner to allow only a partial application of the first fixing layer, which can lead to the advantages described above. By adapting the printing process, different patterns of different, for example punctiform, fixing areas can be made possible in a simple manner.

It can further be provided that the method has the further method step: 1) Hydrophobicizing at least one of the cover layer and the foam, and preferably the respective outer layer.

In this embodiment, a particularly effective watertightness or repelling and beading of water can be made possible without, however, negatively influencing the breathability and thus the water vapor permeability. In the context of the present invention, hydrophobization is to be understood in particular to mean that the textile arrangement or at least parts thereof or the cover layer or at least part thereof have improved hydrophobicity in comparison with that prior to the hydrophobization, or simply treatment with a hydrophobic agent is carried out. For example, the hydrophobization can be carried out with fluorocarbons or fluorocarbon-free DWRs (DWR: durable water repellant; long-lasting water-repellent agent). In particular, hydrophobization can also be carried out with an outside of the layer structure.

For example, this process step can be carried out in that the synthetic leather or the layer structure and thus the faminate is, for example, splashed on one side in an optional, approximately final work step. The outer layer, and in particular the foam or the top layer, can be guided past a rotating roller via guide rollers, the liquor in a container being carried along on the surface of the roller by one plunging of the paddle roller and one-sided to the surface of the top layer or the Foam can be delivered.

It can be advantageous that the splashing is one of the minimum application methods due to the low use of the liquor, which can enable low costs.

With regard to further advantages and technical features of the methods, reference is made to the description of the synthetic leather, and vice versa.

The invention is explained in more detail below with reference to the figures and using an example for producing the synthetic leather.

Fig. 1 shows schematically a sectional view through a first embodiment of an artificial leather;

Fig. 2 shows schematically a sectional view through a further embodiment of an artificial leather; Fig. 3 shows schematically a sectional view through a further embodiment of an artificial leather; 4 schematically shows a method step for producing an artificial leather;

5 schematically shows a further method step for producing an artificial leather; 6 schematically shows a further method step for producing an artificial leather;

7 schematically shows a further method step for producing an artificial leather; and

8 schematically shows a further method step for producing an artificial leather.

Different designs of an artificial leather 10 are shown in FIGS. 1 to 3. Methods or method steps for producing these configurations are shown in FIGS. 4 to 8.

FIG. 1 shows an embodiment of a multilayer synthetic leather 10 which has the following structure. The artificial leather 10 according to FIG. 1 comprises a textile arrangement 12, which can serve in particular as a carrier layer. The textile arrangement 12 consists of a textile layer 14, which is approximately selected from the group consisting of a woven fabric, a knitted fabric, a knitted fabric, a nonwoven fabric or also a 3-D spaced fabric. In principle, the present invention can include the fact that the textile materials described above are not only used in isolation, but also as a suitable mixture comprising at least one of the aforementioned examples.

In addition to the textile arrangement 12 or the textile layer 14, the synthetic leather 10 comprises a polyurethane-based foam 16, which is designed in particular as an impact foam. The polyurethane-based foam 16 can have an impact foam density in a range of 200-700 g / l, but is not strictly limited to this . It is further provided that the polyurethane-based foam 16 is present on the surface and is provided with a structure 18.

In particular, in order to obtain particularly preferred mechanical properties, it is further provided that the polyurethane-based foam 16 also has a silicone.

FIG. 1 further shows that the polyurethane-based foam 16 is partially fixed with the textile arrangement 12 using a first fixing layer 20 such that the first fixing layer 20 is provided with fixing areas 22 formed by a fixing agent and free areas 24 free of the fixing agent are provided in the same plane . In particular, it is provided that the first fixing layer 20 is applied in a punctiform manner and the fixing regions 22 are thereby designed in a punctiform manner. As a result, a comparatively small amount of fixative can be used, for example in an amount of 2-50 g / m ^2, in particular 10 g / m ² to less than or equal to 20 g / m ² .

The fixing agent can preferably be designed as a polyurethane-based hot-melt adhesive, which can also be referred to in the technical field as a so-called hot melt.

FIG. 2 shows an embodiment of an artificial leather 10, which is essentially the same 1 corresponds, which is why the differences are discussed in this regard in particular.

It is provided in the embodiment according to FIG. 2 that the textile arrangement 12 does not consist of a textile layer 14, but rather that the textile arrangement 12 has a textile layer 14 and a water-impermeable membrane 26, the water-impermeable membrane 26 with the textile Layer 14 is partially fixed using a second fixing layer 28 such that second fixing layer 28 is provided by fixing areas 30 formed by a fixing agent and free areas 32 free of fixing agent are provided in the same plane. With regard to the configuration of the second fixing layer 28, reference can essentially be made to the configuration of the first fixing layer 20.

In summary, the membrane 26 can ensure a particularly pronounced watertightness and can be freely selected according to the respective requirement. Polymer-based membranes may be preferred here. For example, polyether esters (PES), polytetrafluoroethylene (PTFE), and polyurethane (PU) can be processed into membranes and are particularly effective here.

The configuration shown in FIG. 3 is again similar to the configuration shown in FIG. 1, which is why the differences are again dealt with essentially.

In the embodiment according to FIG. 3, it is provided that a cover layer 34 is also provided on the polyurethane-based foam 16. The cover layer 34 can, for example, be formed at least in part from an in particular aliphatic polyester-polyurethane dispersion. It is shown that the structure 18 is incorporated into the cover layer 34 and the cover layer 34 forms the top or the outermost layer. Accordingly, the mechanical requirements for the polyurethane-based foam 16 can be reduced, so that it does not need to have any additives, for example, such as, in particular, no silicone.

The production of an artificial leather 10 as described above is described in the following figures. The synthetic leather 10 is particularly preferably produced by a method designed as follows or by the following method steps: a) providing a base 36; b) if necessary, applying the cover layer 34 to the base 36; c) applying the polyurethane-based foam 16 to the base 36 or, if a cover layer 34 is present on the base 36, to the cover layer 34; d) Partial application of the first fixing layer 20 on the polyurethane-based foam 16 under Formation of fixing areas 22 formed by a fixing means and of free areas 24 free of the fixing means in the same plane; e) applying the textile arrangement 12 to the polyurethane-based foam 16 partially provided with the first fixing layer 20; and f) removing the base 36, in particular immediately after method step c).

It can thus be seen from the above that the method is a so-called reversal method in which the synthetic leather 10 is built up from the uppermost or outermost layer to the innermost layer or carrier layer.

With regard to the configuration of the individual layer or layers, reference is made to the explanations relating to synthetic leather 10.

FIG. 4 shows the application of the polyurethane-based foam 16 to the base 36. The base 36 can, for example, be a grained base paper for introducing a structure. In this case, the polyurethane-based foam 16 can be doctored by a doctor blade 38, for example in a one-coat process. This creates a layer sequence 40 with the base 36 and the polyurethane-based foam 16, which can preferably be dried and cured. The pad 36 can now be removed again.

The layer sequence 40 can then run along an application device 42 in order to be able to partially apply the fixing agent, such as a hot melt, to the polyurethane-based foam 16. For this purpose, the layer sequence 40 can be guided by rollers 44 along the application device 42, which has a perforated grid 46 through which the fixing agent can be guided selectively onto the polyurethane-based foam 16. This is shown in FIG. 5.

Then, which is not shown in detail in the figures, the textile arrangement 12, for example the textile layer 14, can be placed on the fixing agent and thus glued to the polyurethane-based foam 16.

Furthermore, as shown in FIG. 6, the layer sequence 50 thus created can again be guided through rollers 48 through a bath 52 with a hydrophobic liquid 54 in order to hydrophobize the layer sequence 50 in this way. This can be done on one side, for example, in order to make only the top layer 34 or the foam 16 hydrophobic. This process step can also be called splashing.

Hydrophobing can also be carried out, for example, by a composite of cover layer 34 and foam 16 or only one foam 16 in a dipping process using a bath 52 is treated with a hydrophobic liquid 54.

FIG. 7 also shows a two-stroke structure. In this case, a cover layer 34 is first applied to the base 36. This can in turn be carried out by means of a doctor blade 38 which distributes the corresponding material on the base 36, which is in turn configured as grained base paper, in a suitable thickness.

Then, as already described above, the polyurethane-based foam 16 can be applied, again by means of a doctor blade 38. In the embodiment shown here, however, this can be done by applying the foam 16 to the cover layer 34.

Then, as already described above and shown in FIG. 8, the layer sequence 50 can run along an application device 42 in order to be able to partially apply the fixing agent, such as a hot melt, to the polyurethane-based foam 16. For this purpose, the layer sequence 50 can be guided by rollers 44 along the application device 42, which has a perforated grid 46, through which the fixing agent can be guided selectively onto the polyurethane-based foam 16.

Then, which is not shown in detail in the figures, the textile arrangement 12, for example the textile Uage 14, can be placed on the fixing agent and thus glued to the polyurethane-based foam 16. The pad 36 can now be removed again.

example

An example is described below by means of which a multi-layer breathable synthetic leather 10 can be produced, wherein the synthetic leather 10 has a carrier layer made of a flat textile structure or a textile arrangement 12, on which a foam 16 formed as a porous whipped foam based on a polyurethane is arranged. The whipped foam is fixed with the textile arrangement 12 as a two-layer laminate by a PUR hot melt adhesive.

1. Paste production for the polyurethane-based whipped foam

The paste is produced in a batch kettle with a stirring dissolver. For this purpose, a polyurethane dispersion is introduced and additives are added in accordance with the recipe (additive 1: aqueous silicone emulsion; additive 2: polyhydrogenmethylsiloxane as crosslinking component 1). Other additives: ammonium stearate as foam stabilizer; Dispersion of an oxime-blocked polyisocyanate cationic / nonionic as crosslinking component 2; HDMI trimer (alternative product: a mixture of MDI and TDI, dry content approx. 30%. Contains 2.5 - 3.0% blocked isocyanate); Melamine resin mixture crosslinker component 3; any Pigment dispersion.

The pH is adjusted to a pH of 9 using 25% ammonia solution. A thickening with an aqueous solution of an acrylic copolymer up to a viscosity of 45 [dPas], with a tolerance of + 5 / - 10, was also carried out . The paste obtained is then pre-filtered into a further batch vessel using a membrane pump with a 100 μm filter.

2 Foaming of the paste with a foam aggregate

The paste obtained previously, which can also be referred to as a compound, is now passed through a foam unit. This is set to the specified parameters, such as compressed air, speed, foam weight and flow rate. When the filtered compound reaches the feed pump in the mixer, foam production begins in the mixing head. The flow is caught in the container provided. After the consistency of the foam 16 has become uniform, the liter weight of the foam 16 is weighed and, if the result is correct, the application hose is attached to the coating head and after reaching the template (a certain amount in front of the knife) production starts.

The following parameters should be adhered to in this example: The viscosity of the coating composition used before foaming should be 45 [dPas], with a tolerance of + 5 / - 10. The foam liter weight of foam 16 should be set to 600 [g / 1] with a tolerance of +/- 30.

3 painting the paste / foam 16

The paste / foam 16 is spread over a doctor blade system using the so-called reversal process on a grained release paper as the base 16. The graining can be selected as desired, depending on the manufacturer.

The overlay is adjusted via the gap thickness to the counter roller or to the release paper. Target pad (dry): 200 ± 15 g / m ² 3.1 Drying + condensation of the paste in the drying tunnel

The paste / foam 16 is dried in a channel with a plurality of separately adjustable temperature zones.

A temperature window of 70 to 110 ° C is run through here. The condensation, complete crosslinking, the coating takes place in a second drying tunnel with several, separately adjustable temperature zones. A temperature window of 150 to 190 ° C is run through here.

The dwell time of the coating in the second channel is decisive for a complete networking of all fixing components. The dwell time is controlled by the speed of the goods in the coating system.

The drying process and the condensation process are crucial for the formation of a fine foam structure of the coating. Partially bursting open the mechanically foamed foam structure creates a partially open-pore coating. This specifically controlled open porosity must be formed uniformly over the entire layer of the coating.

After the coating has passed through the cooling rollers, the coating is delaminated from the release paper in the goods outlet and wound onto a cardboard tube as a semi-finished foam sheet or as a semi-finished product.

Test samples are taken from the finished rolls. These are tested as a foam sheet in the test laboratory with regard to circulation, MVTR value, WVP value, abrasion, foam structure.

Grammage [g / m ² ]: 200 with a tolerance of +/- 15; WVP [mg / cm ² / h]:>10; MVTR [g / m ² / 24h]:>5,500; Abrasion resistance Martindale [tours]> 50,000

4 Lamination of the semi-finished foam sheet using screen print technology

To produce the artificial leather 10, the foam film is glued to the textile using the screen print technology (screen printing application of the adhesive / hot melt). The screen print technology includes squeegeeing the melted adhesive through a perforated template on foam film. The textile backing is attached to the coated foam sheet under pressure. Due to different perforated templates, very precise layers of adhesive can be realized.

For the production of the synthetic leather / laminate, adhesive layers in the range of approx. 10-20 g / m ^{2 are} realized. Due to the technology-related low adhesive layer and an optimal distribution of the adhesive, the breathability of the coating is only minimally influenced.

Adhesive technology: PUR Holtmelt (polyurethane that crosslinks with air humidity

Hot melt adhesives) The products were specially developed for textile lamination, e.g. B. developed for gluing woven and non-woven fibers with PVC, polyester, polyurethane and polyether amide films. The setting time depends on the application temperature, amount of adhesive, type of substrate, temperature of the substrate and the ambient conditions.

Chemical basis: PUR prepolymer Consistency: firm; Density: approx. 1.10 g / cm3; Melt viscosity (Brookfield). The production of the artificial leather 10 via the screen print technology offers a unique possibility to vary the textile substrates or the textile layers 14. In this way, a batch of foam films can be connected to a wide variety of textile substrates.

Optionally, the textile or the textile layer 14 can also have been connected beforehand with a breathable membrane to form a 2-layer laminate, so that the finished synthetic leather / laminate also has a high water column in addition to high breathability. The membrane system can be freely selected according to the respective requirement. Polymer-based membranes are the most widely used membranes. Mainly polyether esters (PES), polytetrafluoroethylene (PTFE), and polyurethane (PU) are processed into membranes.

After the PU adhesive has cured for a suitable period of time, the laminates are prepared for waterproofing on the tenter frame. The last process step 6] is to be seen as optional in order to improve the water repellency of the synthetic leather.

5 Hydrophobization using equipment on a stenter

The artificial leather 10 / laminate is not dipped in the optional last step, as is customary for textiles, but is rather one-sided. Splashing is one of the minimum application procedures due to the low fleet use. The material web is guided past a rotating roller via guide rollers. By immersing the paddle roller, the liquor is carried along on the surface of the roller and released on one side to the surface of the foam 16. This process is carried out using a stenter with separately adjustable temperature zones. The finished synthetic leather 10 is then wound onto a pillar and the goods inspection made available.

The hydrophobization can be carried out with fluorocarbons or FC-free DRWs.

This was followed by a goods inspection or visual inspection and quality control in the test laboratory, whereby the following values could be achieved:

WVP (mg / cm ² / h):> 9 (without membrane 11.5-15.0, especially> 7, with membrane 2.54-9.0, especially>2); MVTR (g / m ² / 24h):> 4,500 (without membrane 3,350 to 4,500, especially> 2000, with membrane 1,600-3,750, especially>1000); Abrasion resistance (tours): 55,000; Spray test> 80.

The following standards were used for the tests:

Air permeability: EN ISO 9237 • Determination of resistance to water penetration / hydrostatic pressure test: DIN EN 20811

• Non-commercial washing and drying processes for testing textiles: DIN EN ISO 6330 · Water vapor permeability: DIN EN ISO 15496 (MVTR [g / m ² 24h]; Moisture Vapor

Transmission Rate (MVTR), also Water Vapor Transmission Rate (WVTR)

• Water vapor permeability: DIN EN ISO 14268: 2013 (WVP [mg / cm ² h])

• Seam sealing: EN 343 20811

• Abrasion: DIN EN ISO 12947-2 · Continuous kink behavior: DIN 53359

• Permanent bending strength: DIN EN ISO 32100

• Spray test - determination of the water-repellent properties (spraying method) of textiles: DIN EN ISO 4920

Reference number:

10 synthetic leather

12 textile arrangement

14 textile layer 16 foam

18 structure

20 first fixing layer

22 fixing area

24 Free area 26 Membrane

28 second fixing layer

30 fixing area

32 outdoor area

34 top layer 36 underlay

38 squeegees

40 shift sequence

42 Application device

44 roller

46 perforated grid

48 roller

50 shift sequence

52 bath

54 liquid

Claims

1. Multi-layer synthetic leather (10), at least having a textile arrangement (12); and a polyurethane based foam (16); wherein the polyurethane-based foam (16) is partially fixed with the textile arrangement (12) using a first fixing layer (20) such that the first fixing layer (20) is formed by fixing regions (22) and in the same plane by the fixing means has free open areas (24).

2. Synthetic leather according to claim 1, characterized in that the first fixing layer (20) is applied in a dot shape, in the form of diamonds or in the form of bars.

3. synthetic leather according to claim 1 or 2, characterized in that the first fixing layer (20) is applied in an amount of> 2 to <50 g / m ² , in particular> 10 g / m ² to <20 g / m ² .

4. Synthetic leather according to one of claims 1 to 3, characterized in that the textile arrangement (12) consists of a textile layer (14).

5. Synthetic leather according to one of claims 1 to 3, characterized in that the textile arrangement (12) has a textile layer (14) and a water-impermeable membrane (26), the water-impermeable membrane (26) with the textile layer (14) is partially fixed using a second fixing layer (28) such that the second fixing layer (28) has fixing areas (30) formed by a fixing agent and free areas (32) free of the fixing agent in the same plane.

6. Synthetic leather according to one of claims 1 to 5, characterized in that a cover layer (34) is further provided on the polyurethane-based foam (16).

7. synthetic leather according to claim 6, characterized in that the cover layer (34) is at least partially formed from a particularly aliphatic polyester-polyurethane dispersion.

8. Synthetic leather according to one of claims 1 to 7, characterized in that at least one of the first fixing layer (20) and the second fixing layer (28) is at least partially formed from a hot melt adhesive or from a particularly aliphatic polyester-polyurethane dispersion.

9. Synthetic leather according to one of claims 1 to 8, characterized in that the polyurethane-based foam (16) has a silicone.

10. synthetic leather according to one of claims 1 to 9, characterized in that the polyurethane-based foam (16) has a solids content of> 40 vol .-%, preferably in a range from> 40 vol .-% to <70 vol .-%, having.

11. A method for producing a multi-layer synthetic leather (10) according to one of claims 1 to 10, comprising the steps of: a) providing a base (36); b) optionally applying a cover layer (34) to the base (36); c) applying a polyurethane-based foam (16) to the base (36) or, if a cover layer (34) is present on the base (36), to the cover layer (34); d) Partial application of a first fixing layer (20) onto the polyurethane-based foam (16) or onto a textile arrangement (12) with the formation of fixing areas (22) formed by a fixing agent and free areas (24) free of the fixing agent in the same plane. ; e) applying the textile arrangement (12) to the polyurethane-based foam (16); and f) removing the pad (36).

12. A method for producing a multilayer synthetic leather (10) according to one of claims 1 to 10, comprising the steps: g) providing a textile arrangement (12); h) providing a polyurethane-based foam (16); i) Partial application of a first fixing layer (20) to the polyurethane-based foam (16) or to the textile arrangement (12), forming fixing areas (22) formed by a fixing agent and free areas (24) free of the fixing agent in the same plane. ; j) joining the polyurethane-based foam (16) and the textile arrangement (12); and k) optionally applying a cover layer (34) to the polyurethane-based foam (16).

13. The method according to claim 11 or 12, characterized in that the first fixing layer (20) is applied in method step d) or in method step i) using a Screen printing process.

14. The method according to any one of claims 11 to 13, characterized in that the base (36) is a grained base paper.

15. The method according to any one of claims 11 to 14, characterized in that the method comprises the further step: 1) hydrophobizing at least one of the cover layer (34) and the foam (16).