STRUCTURED ARTIFICIAL LEATHER MATERIAL COMPRISING WATER-LADEN PARTICLES FROM A RENEWABLE RAW MATERIAL

Abstract

A structured artificial leather material comprising a support layer and an application layer, the application layer comprising particles from a renewable raw material, which are laden with water. A method for producing such a structured artificial leather material is also provided.

Description

This nonprovisional application is a continuation of International Application No. PCT/EP2022/074284, which was filed on Sep. 1, 2022, and which claims priority to German Patent Application No. 10 2021 213 054.2, which was filed in Germany on Nov. 19, 2021, and which are both herein incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a structured artificial leather material having a support layer and an overlay layer arranged on the support layer, wherein the overlay layer includes particles of a renewable raw material, and the particles are laden with water.

Description of the Background Art

Leather is used as an upholstery material for automobile interiors, for example automobile seats, among other purposes, and is valued as a strong, visually attractive, and overall high-quality material. However, leather production has a serious adverse environmental impact due to cattle raising and the processing of the raw leather into the final product, due to the chemicals used in tanning.

Artificial leather is an imitation leather. The primary motivation for using artificial leather is to refrain from genuine leather as an animal product and to eliminate the ecological problems caused by the production of genuine leather.

Generally, a composite composed of a textile base, in particular a knitted fabric, and a plastic cover layer is used in producing artificial leather. The textile materials can be natural fiber textiles, chemical fiber textiles, or blends, and can in turn be coated, for example with plasticized PVC. This coating can be foamed or dense in implementation, depending on the application. The surface can be given an embossed grain so that it resembles leather in structure, as well.

Different methods are known for leather and/or artificial leather production.

CN 108978250 A provides a suede hydrolysis-resistant ultrasoft protein leather and a method for producing the same. The protein leather comprises a base fabric, a wet-method Bayes layer, and a dry-method cover layer.

KR 2018003073A describes the development of environmentally friendly materials.

Artificial leather manufacturing, like leather manufacturing, is also facing concerns in light of steadily intensifying ecological awareness. Because of their petrochemical origin, artificial leather materials have material-specific disadvantages that, in particular, have an adverse effect on the life cycle assessment of the material. The commonly used plastics polyvinyl chloride (PVC) and polyurethane (PU) are based on petrochemicals-what is involved here, therefore, is a nonrenewable raw material or a finite resource.

In addition to the increasingly important ecological aspects, consumers continue to want visually attractive products. In artificial leather products known from the prior art, the surface is given a structure, for example by means of an embossed grain, to match the visual appearance of the surface of the artificial leather material to the look of genuine leather.

The methods known from the prior art for structuring are labor-intensive, however. Furthermore, these methods are geared to conventional artificial leather products made of nonrenewable raw materials. In addition, the results of these methods are not yet entirely convincing visually, especially with regard to whether an authentic-seeming surface structure is created.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide an artificial leather material that: overcomes the disadvantages in ecological terms of known leather materials and artificial materials; has an innovative, visual appearance; and furthermore is simple to manufacture.

The invention attains these objects wholly or partially in that, according to a first aspect of the invention, a structured artificial leather material is provided, comprising: a support layer, and an overlay layer arranged on the support layer, wherein the overlay layer includes particles of a renewable raw material, and the particles are loaded with water.

The artificial leather material according to the invention thus reduces the use of nonrenewable raw materials by means of at least proportionate use of renewable raw materials. In other words, a strong, visually attractive, and overall high-quality material is provided that at the same time overcomes, to the greatest extent possible, the disadvantages in ecological terms of known leather materials and artificial leather materials. The invention thus represents a reduction of the ecological footprint of the leather that is traditionally used.

Since no labor-intensive embossed graining is required, the material is simple to manufacture and has an especially authentic and innovative visual effect. Thus, the artificial leather material has an entirely novel and unique visual appearance that is different from previous artificial leathers. The reason is that the structured artificial leather material has a multiplicity of structure elements that are irregularly distributed over the surface of the artificial leather material. These structure elements are produced by a rupturing of the surface of the artificial leather material during the embossing step in the production of the artificial leather material, and can be attributed to the loading of the particles with water. In the case of a conventional artificial leather material, no loading with additional water takes place. In contrast to the artificial leather material according to the invention, such an artificial leather material does not have a multiplicity of structure elements, but instead forms an essentially homogeneous surface. A structuring must be produced in these cases by additional embossing processes, for example.

In other words, the structuring of the surface in the case of the present invention occurs by means of the water-laden particles. The structuring of the surface consequently also stems from the inherent property of the renewable raw materials for binding and releasing water. Additional labor-intensive structuring steps can then be omitted, thus making the manufacturing process simple and efficient.

It was discovered in this connection that, when the renewable raw material includes silverskin of coffee fruits, in particular when the particles are formed essentially of silverskin of coffee fruits, an especially good loading of the particles with water is possible. The use of silverskin from coffee fruits as a renewable raw material is thus especially preferred, since the rupturing of the surface of the material, and thus a surface structuring, can be brought about deliberately.

The invention employs renewable raw materials, on the one hand in order to provide an ecologically more sustainable technical solution for artificial leather materials, and on the other hand takes advantage of the inherent properties of the renewable raw materials to create an especially authentic visual effect in a simple manufacturing process.

The term “structured artificial leather material” can be interpreted according to the present invention to mean that the artificial leather material has a nonhomogeneous surface structure. The term can further be understood here to mean that the structured artificial leather material has a multiplicity of structure elements that are distributed over the surface of the artificial leather material. In particular, the surface structure has irregularities, at least in parts. In particular, the structure elements are irregular insofar as they are unequally spaced, at least in parts, and/or differ from one another in shape and/or size, and/or are present at a higher density in some regions of the surface of the artificial leather material than in other regions. These structure elements further preferably arise due to a rupturing of the surface of the artificial leather material during and/or after the embossing step in the production of the artificial leather material.

If it is stated in connection with the present invention that “an overlay layer is arranged on the support layer,” then the feature should not to be interpreted restrictively to the effect that the overlay layer is arranged directly on the support layer. On the contrary, still further layers can be arranged between the overlay layer and the support layer. According to an example, the statement can be understood to mean that the overlay layer is arranged directly on the support layer. This applies analogously for corresponding other features.

An artificial leather material can be described wherein the renewable raw material of the first overlay layer is chosen from one or more of the following group: wood flour, coffee fruits, corncobs, sugar beet flour, grain stalk flour, and/or flour of spent brewers' grain.

An artificial leather material can be described wherein the renewable raw material of the first overlay layer includes coffee fruits, in particular silverskin of coffee fruits.

An artificial leather material can be described wherein the renewable raw material in the overlay layer is present in a quantity of at least 10 percent by weight, preferably at least 20 percent by weight.

If it is stated in connection with the present invention that “the particles are loaded with water,” what is meant by this is the adjustment of the physically bound water content of the particles within a defined range. Water that is physically bound to the particles is water that is externally associated to the particles after the drying step. This is to say, in particular, the water that is added, after complete drying, to the ground particles by loading of the particles. The water content after complete drying is defined in this case as the zero point. The physically bound water content then corresponds to the water added to the particles after this point.

Methods for measuring the water content of the particle and subsequently to adjust it in a defined manner are known to the person skilled in the art. “Particles loaded with water” thus have a defined water content.

An artificial leather material can be described wherein the particles have a physically-bound water content from 0.1 percent by weight to 10 percent by weight, preferably 1 percent by weight to 10 percent by weight, further preferably 1 percent by weight to 5 percent by weight, still further preferred is a range from 2 percent by weight to 5 percent by weight.

An artificial leather material can be described wherein the particles have a total water content from preferably 2 percent by weight to 20 percent by weight, further preferably from 5 percent by weight to 15 percent by weight. The total water content can be determined by means of Karl Fischer titration.

The structured artificial leather material can have a multiplicity of structure elements that are produced by a rupturing of the surface of the artificial leather material during the embossing step in the production of the artificial leather material and can be attributed to the loading of the particles with water. This is the reason why a water content of at least 0.1 percent by weight is preferred; further preferred is at least 1 percent by weight. However, it was surprisingly found that also when the water content is too high, in particular over 10 percent by weight, the material cannot be worked as well, structural damage can occur, and the artificial leather material is visually less attractive. In particular, the best results were attained at a water content of not more than 5 percent by weight.

The water content can be calculated in relation to the total weight of the particles.

An artificial leather material can be described wherein the particles on average have a diameter of 10 to 100 μm. The particle size determines the capacity to be loaded with water, among other things. It was found that the best results could be achieved with particles that have a diameter of 10 to 100 μm on average. With these diameters, the water of the particles that are loaded with water can preferably expand, which leads to a rupturing of the surface.

At least 80%, preferably 90%, of the particles can have a diameter in the range from 10 to 100 μm. It was found that the expansion property of the water of the particles, and thus the ability to structure the surface, represents a function of an interaction of particle size and water content, wherein it was found, in particular, that the best results could be achieved with particles that have, on average, a diameter from 10 to 100 μm and have been loaded with 2 to 5 percent by weight of water. With these diameters and water content values, the water can preferably expand, which leads to an especially advantageous surface structuring.

An artificial leather material can be described wherein the particles have, on average, a diameter from 10 to 100 μm, and the particles have a physically-bound water content from 2 to 5 percent by weight.

An artificial leather material can be described wherein a first overlay layer is implemented as an adhesive layer that joins the support layer to a second overlay layer. This embodiment offers a particular degree of stability and confers durability on the artificial leather material.

A structured artificial leather material can be described wherein the overlay layer is implemented as a foam layer.

An artificial leather material can be described wherein the overlay layer can include synthetic polymer materials, preferably PVC, polyurethanes, and/or polyols. The particles that include the renewable raw material or are generated therefrom are incorporated into the polymer matrix as filler particles. The polymer matrix in this case is preferably a foamed polymer matrix. The filler particles that are loaded with water can preferably interact with the polymer matrix such that the water expands within the matrix, which results in a rupturing of the surface.

An artificial leather material can be described wherein the particles is formed essentially of a renewable raw material.

It was found that it is possible to achieve a reliable adhesion of the overlay layer or the overlay layers to the support layer by means of the adhesive layer, even with high proportions of renewable raw materials in the adhesive layer.

An artificial leather material can also be described wherein the support layer can include a renewable raw material, in particular natural fibers, which preferably are chosen from one or more of the following group: linen, nettle, hemp, ramie, pineapple, and cotton. In addition, synthetic fibers from renewable raw material sources can be used, for example regenerated cellulose.

An adhesive layer can bond a further overlay layer or further overlay layers to the support layer.

An artificial leather material can be described wherein the artificial leather material furthermore includes a second overlay layer, wherein the second overlay layer is arranged on the first overlay layer, and wherein the second overlay layer includes particles of a renewable raw material, in particular silverskin of coffee fruits, and the renewable raw material is present in a quantity of at least 10 percent by weight, preferably of at least 20 percent by weight, with respect to the total weight of the overlay layer.

An artificial leather material can be described wherein the first overlay layer includes particles of a renewable raw material, in particular silverskin of coffee fruits, and the renewable raw material is present in the first overlay layer in a quantity of at least 10 percent by weight, preferably of at least 20 percent by weight, and wherein the second overlay layer includes particles of a renewable raw material, in particular silverskin of coffee fruits, and the renewable raw material is present in a quantity of at least 10 percent by weight, preferably of at least 20 percent by weight, and the support layer is made essentially of a knitted fabric.

In this way, it is possible that the leather material as a whole has a high proportion of renewable raw material.

It was discovered that an overall proportion of renewable raw materials of 30 percent by weight or more is possible in the artificial leather material without the properties of the artificial leather, such as the tear resistance, being limited, especially when the first overlay layer and the second overlay layer have silverskin particles in a quantity of at least 20 percent by weight and the support layer is made essentially of a woven fabric. It is therefore possible by this means to provide a strong, visually attractive, and overall high-quality material that at the same time overcomes, to the greatest extent possible, the disadvantages in ecological terms of known leather materials and artificial materials.

An artificial leather material can be described wherein the artificial leather material additionally includes a third overlay layer, which preferably is implemented as a cover layer; and/or a fourth overlay layer, which preferably is implemented as a varnish layer and/or sealing layer.

The artificial leather material according to the invention can be used in a vehicle, in particular for vehicle interiors. For example, vehicle seats but also controls and instruments can be understood as vehicle interiors. The artificial leather material according to the invention can replace already known artificial leather material in application. Concrete application cases are evident in the area of the apparel industry, for example for shoes, luggage, and tote bags, as well as upholstery material for furniture.

The various examples and embodiments of the invention cited in this application can be combined with one another to good advantage unless otherwise stated in the individual case.

According to another aspect, the invention describes a method for producing a structured artificial leather material comprising the steps: providing a support layer; providing particles from a renewable raw material; loading the particles with water; providing a first overlay layer comprising the particles; and arranging the overlay layer on the support layer.

A method for producing a structured artificial leather material can be described wherein the method furthermore includes an embossing step, wherein the embossing step leads to a partial rupturing of the surface.

A method for producing a structured artificial leather material can be described wherein the method furthermore includes: a grinding step, wherein the particles are ground; and a drying step, wherein the ground particles are completely dried, wherein the drying step takes place before the loading of the particles with water.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes, combinations, and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

FIG. 1 shows a layer structure of an artificial leather material according to the invention in an example;

FIG. 2 shows a coffee fruit in an explanatory representation;

FIG. 3a shows a non-structured surface of an artificial leather material according to the prior art; and

FIG. 3b shows a structured surface of an artificial leather material according to the invention.

DETAILED DESCRIPTION

FIG. 1 shows a layer structure of an artificial leather material 10 according to the invention in an example. The artificial leather material 10 includes a support layer 5 and multiple overlay layers 1, 2, 3, 4, which are arranged on the support layer 5.

The support layer 5 confers the requisite mechanical properties, such as tear resistance, on the artificial leather material 10. The support layer 5 is therefore preferably implemented as a textile layer. Even though synthetic fiber materials can in principle also be used for the support layer 5, a support layer 5 that is implemented as a natural fiber knitted fabric is preferred. The concept according to the invention of providing an ecological artificial leather material is taken into account by this means. The natural fibers can be made, for example, of linen, nettle, hemp, ramie, pineapple, and cotton.

The first overlay layer 4 is implemented as an adhesive layer. The adhesive layer 4 bonds the overlay layers 1, 2, 3, 4 to the support layer 5.

The adhesive layer 4 includes a renewable raw material. In particular, it was determined that coffee fruits 20, whose structure is described in FIG. 2, are suitable. It was determined in connection with the invention that particles of the silverskin 26 from coffee fruits 20, in particular, are appropriate as a filler for the adhesive layer 4. Silverskin 26 from coffee fruits 20 is generated as a byproduct of coffee production. It is therefore especially appropriate as an ecological filler for the adhesive layer 4. It was furthermore discovered that the use of silverskin particles permits a concentration of over 20 percent by weight, as a rule even over 30 percent by weight, in the adhesive layer 4.

The second overlay layer 3 is implemented as a foam layer. The foam layer 3 confers the desired consistency and elasticity on the artificial leather material 10.

The foam layer 3 includes a renewable raw material. In particular, it was determined that coffee fruits 20, whose structure is described in FIG. 2, are suitable. It was determined in connection with the invention that particles of the silverskin 26 from coffee fruits 20, in particular, are appropriate as a filler for the foam layer 3. As already noted, silverskin 26 from coffee fruits 20 is generated as a byproduct of coffee production. It is therefore especially appropriate as an ecological filler for the foam layer 3. It was furthermore discovered that the use of silverskin particles permits a concentration of over 20 percent by weight in the foam layer 3.

The third overlay layer 2 is implemented as a cover layer. The cover layer functions as an intermediate layer and confers an attractive visual effect on the artificial leather material 10. For example, the overlay layer 2 can include one or more coloring agents in order to confer a color on the artificial leather material. Furthermore, the surface of the artificial leather material can be textured by means of the cover layer. The surface texture that is usual in natural leather, for example in the form of small scratches, can be imitated by means of the cover layer.

The fourth overlay layer 1 is implemented as a varnish layer or lacquer layer, and confers, for example, nonstick properties and scratch-resistance on the material.

The varnish layer 1 has a mass per unit area of approximately 60 g/m², for example. The cover layer 2 has a mass per unit area of approximately 300 g/m², for example. The foam layer 3 has a mass per unit area of approximately 270 g/m², for example. The adhesive layer 4 has a mass per unit area of approximately 115 g/m², for example.

FIG. 2 schematically shows a coffee fruit 20 in an explanatory representation. Regardless of the species of the coffee variety, the coffee fruit 20 comprises a coffee bean 28 and fruit pulp 22. Covering the coffee beans is the silverskin 26, also referred to as silver skin, which in turn is surrounded by a parchment 24 and a pectin layer. The silverskin 26 and the parchment 24 serve as a sort of protective layer around the beans 28. The silverskin 26 and the parchment 24 are so fine and thin that they are almost transparent. Located atop the pectin layer is the fruit pulp 22, also referred to as pulp. The surface of the coffee fruit is formed by a pericarp, or skin, which lends the coffee fruit 20 the name “coffee cherry” because of its generally red color. The silverskin 26 of coffee fruits 20 is generated as a byproduct of coffee production, since mainly the coffee bean is utilized in coffee production. The silverskin 26 is therefore especially appropriate as an ecological filler for the artificial leather material according to the invention.

FIG. 3a shows a non-structured surface of an artificial leather material 14.

FIG. 3b, in contrast, shows a structured surface of an artificial leather material 10 according to the invention.

The structured artificial leather material 10 from FIG. 3b was produced by means of the method according to the invention. This method comprises the steps: provision of a support layer and provision of particles from a renewable raw material. In order to make the particles, the renewable raw material was ground, then loaded with additional water and incorporated in an overlay layer. In addition, the artificial leather material was subjected to an embossing step. The structured artificial leather material 10 thus obtained has a multiplicity of structure elements 12, which are distributed over the entire surface of the artificial leather material. These structure elements 12 are produced by a rupturing of the surface of the artificial leather material during the embossing step, and can be attributed to the loading of the particles with water.

In the case of the non-structured artificial leather material 14 in FIG. 3a, the renewable raw material was ground, but not loaded with additional water. The artificial leather material was likewise subjected to an embossing step. The artificial leather material 14 thus obtained does not have a multiplicity of structure elements. Instead, the artificial leather material forms an essentially homogeneous surface, and does not achieve the authentic visual effect of the material according to the invention.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.

Claims

1. A structured artificial leather material comprising:

a support layer; and

an overlay layer arranged on the support layer, the overlay layer comprising particles of a renewable raw material, and the particles are loaded with water.

2. The structured artificial leather material according to claim 1, wherein the renewable raw material includes components of coffee fruits and/or silverskin of coffee fruits.

3. The structured artificial leather material according to claim 1, wherein, wherein the renewable raw material is present in a quantity of at least 10 percent by weight or at least 20 percent by weight, with respect to a total weight of the overlay layer.

4. The structured artificial leather material according to claim 1, wherein the particles have a content of physically bound water from 1 percent by weight to 10 percent by weight or 2 percent by weight to 5 percent by weight.

5. The structured artificial leather material according to claim 1, wherein the particles have, on average, a diameter from 10 μm to 100 μm.

6. The structured artificial leather material according to claim 1, wherein the overlay layer is a foam layer.

7. The structured artificial leather material according to claim 1, wherein the artificial leather material comprises:

a first overlay layer; and

a second overlay layer that is arranged on the first overlay layer, wherein the first overlay layer and/or the second overlay layer comprises particles of a renewable raw material and/or silverskin of coffee fruits, wherein the renewable raw material is present in a quantity of at least 10 percent by weight or at least 20 percent by weight, wherein the particles are loaded with water, and wherein the first overlay layer is an adhesive layer that joins the support layer to the second overlay layer.

8. The structured artificial leather material according to claim 1, wherein the structured artificial leather material has structure elements that are produced by a rupturing of the surface of the artificial leather material.

9. A method for producing a structured artificial leather material according to claim 1, the method comprising:

providing a support layer;

providing particles from a renewable raw material;

loading the particles with water;

providing a first overlay layer comprising the particles; and

arranging the first overlay layer on the support layer.

10. The method for producing a structured artificial leather material according to claim 9, wherein the method further comprises an embossing step, and the embossing step leads to a partial rupturing of the surface.