A method for producing a water-based and vegan waste (lignin)-based eco-friendly vegan artificial leather

Abstract

This invention relates to the leather production using "lignin (3)", a by-product produced in large quantities by the paper mills, and fabric waste (4) obtained from the recycled yarns for producing a vegetable-based artificial leather (1). In this way, the wastes produced from the different industries are recycled and a new water-based product is obtained without using the new chemical materials. The object of the present invention is to use a new laminate for the production of artificial leather with lignin (3) waste produced in large quantities (tons) in paper mills. The leather obtained has a thickness of 0.2 to 0.3 mm and comprises between 25% and 30% of lignin. This laminate is similar to natural leather in terms of visual and durability properties. Since the prepared laminate is water-based in terms of the materials used, it shows the environmental friendliness and eco-compatibility features. The artificial leathers (1) obtained in this invention show the different mechanical properties depending on the different formulations applied. In this way, it has the potential to be used in various fields (clothing, fashion, home furnishings and car decoration).

Description

[0001] A METHOD FOR PRODUCING A WATER-BASED AND VEGAN WASTE (LIGNIN)- BASED ECO-FRIENDLY VEGAN ARTIFICIAL LEATHER

[0002] TECHNICAL FIELD

[0003] This invention relates to the leather production using “lignin”, a by-product produced in large quantities by the paper mills, and fabric waste obtained from the recycled yarns for producing a vegetable-based artificial leather with the potential to be used in various fields (clothing, fashion, home furnishings and car decoration).

[0004] The term lignin in the invention includes different lignin derivatives such as soda lignin, sodium lignosulfonate, potassium lignosulfonate, magnesium lignosulfonate, kraft lignin, organosolv lignin.

[0005] The water-based lignin used in coating formulations in the invention can be used in powder form or dissolved in organic solvents (dimethylformamide, methyl ethyl ketone, methanol) in the production of PU or PVC-based imitation leather through the same production procedure.

[0006] STATE OF THE ART

[0007] Fashion is known as one of the most profitable industries and also one of the most polluting industries. One of the most polluting ones among the fashion industries is the leather industry. Nearly 130 different chemicals, including cyanide and chromium, are used for tanning the animal skins. This has negative effects on human health and environmental pollution.

[0008] These problems and the problems and cost for the production of the natural leathers have increased the demand for the production of the artificial leathers, which imitate the surface effect of the natural leather, over the years. Polyurethane (PU) or polyvinyl chloride (PVC) is widely used in the production of the artificial leathers with these properties. Artificial leather is produced with the use of synthetic polymeric sheet materials that imitate the appearance of natural leather, containing the plant compounds. In our daily life, such materials replace natural leather in the manufacture of handbags, wallets, upholstery, home and car seats, etc. and in the clothing and textile industry. Such synthetic leather materials are generally produced by coating or laminating the plants placed on a natural fabric or non-woven fabric (non-woven fiber) with the synthetic resinous polymers. In the existing patents, the production of the artificial leathers with different characteristics is reported by using different plants and water-based synthetic polymeric layers.

[0009] Recently, in order to reduce environmental pollution, it has been preferred to use the water-based and cellulosic natural polymers with biodegradable properties to reduce the amount of PU or PVC (used by preparing a solution using the chemical solvents) used in the production of the artificial leather.

[0010] In the patent application WO 2008 / 012662, which is similar to this invention, the wastes obtained from the fruit industry, especially from the processing of apples, are used in the production of the artificial leather. In the method described in this application, the compositions consisting of apple powder were formed into a leather-like laminate with a natural adhesive. However, it has been stated that the product is difficult to process and at the same time has low resistance to stress and use.

[0011] In the prior art patent application JP H0430442A, the artificial leather is produced by using a synthetic resin as a result of the plant material undergoing a series of processes. As an important point in this description, it is emphasized that the desired properties can only be obtained by using the synthetic resin. This draws attention as an important obstacle for the artificial leather fabrication.

[0012] In the patent application CN111344451 A, the foam obtained by the flocculation of the apple wastes in PU is used as a source of cellulose for the production of the artificial leather.

[0013] DEFINITION OF THE INVENTION The present invention eliminates the disadvantages described in the state of the art and meets the needs.

[0014] In the present invention, the lignin waste, which is produced in large quantities in paper mills, is used for the first time. In this way, the wastes are recycled for the leather production, providing economic benefits to our country. In addition, the lignin is also available in water-soluble form, and as the most important advantage of this invention and a breakthrough feature in the artificial leather production, it can be used in all kinds of artificial applications and will contribute to the mechanical resistance as it is in soluble form.

[0015] Today, the need for leathers, which do not use chemical solvents and in which the new synthetic wastes of vegetable origin are recycled, continues. Therefore, in this invention, the lignin, which is the waste of paper mills and is biodegradable in the laminate structure, is used for the artificial leather production. Another importance of the invention is the use of recycled ground fabric obtained from the waste yarns. The fact that it is obtained with this fabric is one of the most important features of this patent. Another important feature of the invention is that it is produced in the water phase without using toxic and hard-to-remove solvents such as dimethylformamide, which are widely used in the artificial leather production, in other words, without the use of the chemical solvents. The most important advantage of the present invention is that the product is obtained by using the water-based PU.

[0016] REFERENCE NUMERAL LIST

[0017] 1 : Artificial leather

[0018] 2: PU

[0019] 3: Lignin and derivatives thereof

[0020] 4: Fabric

[0021] 5; A schematic drawing showing the steps performed for the fabrication of the artificial leather in this invention

[0022] 6. Main component

[0023] 7; Transfer paper

[0024] 8; Heating roller

[0025] 9; Baking oven 10; Lignin-containing coating pulp

[0026] 11 ; Adhesive pulp

[0027] 12; Fabric layer

[0028] 13; Removing the artificial leather from the transfer paper

[0029] BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Fig. 1 : A representative view of said invention (Water-based and vegan waste (lignin)- based eco-friendly vegan artificial leather)

[0031] Fig. 2: A schematic drawing showing the steps performed for the fabrication of the artificial leather

[0032] DESCRIPTION OF THE INVENTION

[0033] This invention relates to a water-based and vegan waste (lignin)-based eco-friendly vegan artificial leather (1).

[0034] The water-based and vegan waste (lignin)-based eco-friendly vegan artificial leather (1) consists of a PU (2) layer, a Lignin (3) (by-product of the paper firm) layer, and a fabric (4) layer.

[0035] Description of the layers forming the water-based and vegan waste (lignin)-based eco- friendly vegan artificial leather (1):

[0036] PU (2) layer: It does not show any toxic properties and provides imitation of the superficial appearance of natural leather. Thanks to its high mechanical properties (tensile rupture), the PU (2) layer provides high durability to the water-based and vegan (lignin (3))-based eco-friendly vegan artificial leather (1 ). In this way, the invention has high resistance to the tears and scratches. They are used in the production of the dimethylformamide-based PU and PVC-based imitation leather, since the lignin derivatives have the property of dissolving in different organic solvents other than water solvent. This gives the final product an environmental friendliness feature as well as the desired mechanical properties. Lignin (3) (by-product of the paper firm) layer: The water-based and vegan waste (lignin (3))-based eco-friendly vegan artificial leather (1) gives the vegan feature. The biodegradation feature provides the environmental friendliness feature to the waterbased and vegan waste (lignin (3))-based eco-friendly vegan artificial leather (1). The vegan artificial leather (1) can be produced using the bio-polyurethane and lignin (3).

[0037] Fabric (4) layer: The fabric (4) used in this invention is a recycled fabric made from waste yarn (the same studies obtain the same formula using cotton fabric and fabrics containing all kinds of cotton / polyester blends). In this way, it contributes to the recycling of waste and benefits the country economically. The fabric (4) layer gives the leather a textile feature and makes it suitable for clothing purposes. For example, a non-fabric leather in contact with human skin can cause sweating and the skin to become airless after a while.

[0038] Thereafter, a description is given in Fig. 2 with a schematic drawing showing the steps performed for the fabrication of the artificial leather.

[0039] Main component (6) (aliphatic polyester-based aqueous PU (2) dispersion, polyether ester PU (2)). It does not show any toxic properties and provides imitation of the superficial appearance of natural leather. PU (2) also increases the mechanical properties of the artificial leather (1). The different pigments can be used in this layer, depending on the area of use and preference, and the leathers with various color tones can be obtained. For the first coating step, the pre-specified color pigment is mixed with the water-based PU (2) pulp by a mechanical stirrer and spread on the transfer paper (7) with a doctor blade in a certain thickness. The blocked polyisocyanate is used to adjust the mechanical properties of the PU (2) layer depending on the place of use. The silicone-based surface conditioner provides that the PU (2) layer is easily removed from the transfer paper (7).

[0040] Transfer paper (7): The application was performed using the transfer paper (7) instead of the fabric used in the production of the artificial leather (1). The paper suitable for the water-based polymeric structures is used as the transfer paper (7). The patterned transfer paper (7) imitating the different leather marks is used, and in this way, the artificial leather (1) imitating the appearance of the genuine leather is obtained. The transfer paper (7) used in this step is selected from the papers suitable for the water- based polymeric structures. In this way, tearing and deformation of the transfer paper (7) is prevented during the production. Thanks to finding the different solution methods for skin defects on the leather surface and increasing innovations in the fashion trend in recent years, many different techniques have been started to be developed / applied in the leather finishing. One of them is the creation of the leathers with the paper transfer printing method and a wide variety of skin-printed works. In this way, the skin faults and defects on the leather are covered perfectly and the leathers can be obtained with higher quality. Again, as a result of the application of a rich variety of pictures and similar patterns on the leather with the transfer paper (7), the leathers can be used in a wide variety of fields and create a rich resource for the fashion industry. It is extremely important that the transfer papers (7) are resistant to the high temperatures and pressure.

[0041] Heating roller (8): It is used to spread PU (2) in desired thicknesses on transfer paper (7). This step can be performed manually and / or automatically. An automatic heating roller (7) is used for the large-scale production of the artificial leather (1). It is also used for spreading the adhesives and crosslinkers used to bind the lignin (3) layer and the fabric (4).

[0042] Baking oven (9): It removes the water phase of the PU (2) and lignin (3) layers and ensures the adhesion of the fabric (4) to the leather. It is also operated at different temperatures, dwell times and ventilation cycles to increase the effect of the adhesive / crosslinker.

[0043] Lignin (3)-containing coating pulp (10): In this step, the lignin (3) waste-containing coating which provides the vegan feature is carried out. It can be made in different thicknesses depending on the place of use, and thus the artificial leather (1) with different properties can be obtained.

[0044] The second coating formula used for this purpose is prepared by adding into the water-based PU (2) solution and mixing for 5 minutes with a mechanical stirrer until the mixture becomes homogeneous. The lignin-containing mixture is stripped on the first coating (PU (2) layer) at the desired thickness (determined by the weight scale) and dried in the oven for 3-6 minutes (drying can be varied according to the thickness of the material). Adhesive pulp (11): A blocked polyisocyanate formulation containing a crosslinker is used to ensure that the vegan lignin (3) layer is bound to the fabric (4). It is used to bind the lignin (3) vegan layer of the leather to the fabric (4) layer. The aliphatic polyether ester-based aqueous PU (2) dispersion as the main component (6) of the formulation, PU (2) thickener, silicone-based surface conditioner as regulating (stabilizing) agent that facilitates separation from the transfer paper (7), blocked polyisocyanate, inorganic pigment, and coloring agent are used.

[0045] As seen in the steps of Fig. 2, the fabric layer (12): The recycled fabric (4) made from waste yarn is placed on the adhesive layer (11) and pressed by the heating roller (8) (any roller). The fabric (4) used has a porous structure and a significant increase in the surface bonding area occurs as a result of the adhesive pulp (11) entering the pores during pressing. It provides a strong bonding of the fabric (4) with a porous structure to the previous layers (PU (2) and Lignin (3)). At this step, the fabric (4) is placed on the stripped adhesive and pressed with the heating roller (8). In this way, the adhesive pulp (11 ) penetrates into the pores, creating a higher bonding area. At the end of these processes, the artificial leather (1) with the fabric (4) is baked in the oven for 3-6 minutes. During this process, the cross-linking compounds in the adhesive pulp (11) ensure that the artificial leather (1) is kept in a solid structure.

[0046] Removing the artificial leather from the transfer paper (13) as seen in Fig. 2: After all steps are completed, it can be easily separated from the transfer paper (7) without tearing, thanks to the special formulation used. Thanks to the formulation (silicone- based surface conditioner) used in the PU (2) layer, the leather obtained can easily be separated from the transfer paper (7). In this way, the artificial leather (1) becomes ready for use.

Claims

CLAIMS1 . A water-based and vegan waste (lignin)-based eco-friendly vegan artificial leather (1 ), characterized in that it consists of a PU (2) layer, a Lignin (3) (by-product of the paper firm) layer, and a fabric (4) layer.

2. A water-based and vegan waste (lignin)-based eco-friendly vegan artificial leather (1) according to claim 1 , characterized in that it comprises a main component (6) consisting of an aliphatic polyester-based aqueous PU (2) dispersion and a polyether ester PU (2).

3. A water-based and vegan waste (lignin)-based eco-friendly vegan artificial leather (1 ) according to claim 1 , characterized in that as fabric (4), it comprises a recycled fabric (4) made from waste yarn or cotton fabric (4) and fabrics (4) containing all kinds of cotto n / polyester blends.

4. The production of the water-based and vegan waste (lignin)-based eco- friendly vegan artificial leather (1), characterized in that it comprises the steps of:• A - mixing the main component (6) with the aliphatic polyester-based aqueous PU (2) dispersion and polyether ester PU (2) (pre-specified color pigment water-based PU (2) pulp) by a mechanical stirrer for the first coating step, and spreading it in a certain thickness on the transfer paper (7) using a baking oven (9) by a heating roller (8),• B- spreading the Lignin (3)-containing coating pulp (10) on the layer obtained above,• C- spreading the adhesive pulp (11 ) on the layer obtained above,• D- placing the recycled fabric (4) made from waste yarn on the adhesive layer (11), pressing it by the heating roller (8) and heating it using the baking oven (9),• E - removing the artificial leather from the transfer paper (13).

5. The production of the water-based and vegan waste (lignin)-based eco- friendly vegan artificial leather (1) according to claim 4, characterized inthat it comprises the steps of adding into the water-based PU (2) solution in the step B, mixing for 5 minutes with a mechanical stirrer until the mixture becomes homogeneous, stripping the lignin-containing mixture on the first coating (PU (2) layer) at the desired thickness (determined by the weight scale), and drying in the oven for 3-6 minutes.

6. The production of the water-based and vegan waste (lignin)-based eco- friendly vegan artificial leather (1 ) according to claim 4, characterized in that a blocked polyisocyanate formulation containing a crosslinker is used to provide the bonding of the vegan lignin (3) layer to the fabric (4).

7. The production of the water-based and vegan waste (lignin)-based eco- friendly vegan artificial leather (1 ) according to claim 4, characterized in that the aliphatic polyether ester-based aqueous PU (2) dispersion as the main component (6) of the formulation, PU (2) thickener, silicone-based surface conditioner as regulating (stabilizing) agent that facilitates separation from the transfer paper (7), blocked polyisocyanate, inorganic pigment, and coloring agent are used in the steps.

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