LEATHER-LIKE MATERIAL OF VEGETABLE ORIGIN MADE FROM PERSIMMON PUREE

Abstract

The present invention relates to a vegan and reusable leather type material of vegetable origin, at least 50% and preferably at least 80% biobased. This material is based on a composition which comprises persimmon (Diospyros kaki) mass and a polymer derived from a polyol of vegetable origin. The invention also discloses the process for obtaining the material. The leather-type material may be used in a variety of goods products in the textile such as clothes, footwear products or accessories. The material has proven to keep the same mechanical properties as the animal origin or synthetic leather, being a sustainable alternative which, in addition, contributes to circular economy. The sustainable material, leather-type of vegetable origin, provides an alternative to known leathers, with less environmental impact.

Claims

1. A composition for vegan leather comprising persimmon (Diospyros kaki) and a polymer derived from a polyol of vegetable origin.

2. The composition of claim 1, wherein the persimmon represents between 20-60% wt. in respect of the total weight of the composition and the polymer represents between 40-80% wt. in respect of the total weight of the composition.

3. The composition of claim 1, wherein the persimmon represents between 30-40% wt. in respect of the total weight of the composition and the polymer represents between 60-70% wt. in respect of the total weight of the composition.

4. The composition of claim 1, wherein the polymer is a plasticized starch derived from starch and a glycerol of vegetable origin, preferably the starch is corn starch.

5. The composition of claim 1, wherein the polymer is a polyurethane derived from vegetable polyols.

6. The composition according to claim 1, which further comprises between 0.1-1% wt. in respect of the total weight of the composition of a dye of vegetal origin.

7. The composition according to claim 1, which further comprises between 1-10% wt. in respect of the total weight of the composition of a vegetal oil selected from sesame oil, canola oil, sunflower oil, soybean oil, peanut oil, olive oil, corn oil, bean oil, grapeseed oil, jojoba oil, palm oil, cotton seed oil, almond oil, safflower oil, walnut oil, avocado oil, rice bran oil, and flaxseed oil.

8. The composition according to claim 1, which further comprises between 0.5-2% wt. in respect of the total weight of the composition of an additive selected from thickeners, crosslinkers, stabilizers.

9. A vegan leather material comprising the composition according to claim 1.

10. The material of claim 9, which is a layered material comprising the following layers: a) a top layer comprising waterborne polyurethane, b) a second layer comprising the composition according to claim 1 c) a third layer comprising a waterborne polyurethane with adhesive properties, and d) optionally, a fourth layer which is a textile layer.

11. The material of claim 10, wherein the layer (a) represents between 10-20% wt. in respect of the total weight of the material, and/or the layer (b) represents between 20-70% wt. in respect of the total weight of the material, and/or the layer (c) represents between 2-10% wt. in respect of the total weight of the material and/or the layer (d) represents between 30-50% wt. in respect of the total weight of the material.

12. The material of claim 10, wherein the layer (a) is coated with a composition comprising a wax and a vegetable oil.

13. The material of claim 12, wherein the wax and the vegetable oil are in 1:1 ratio.

14. The material of claim 12, wherein the wax is selected from bee wax, montan wax, candelilla wax and carnauba wax.

15. The material of claim 11, wherein the vegetable oil is selected from sesame oil, canola oil, sunflower oil, soybean oil, peanut oil, olive oil, corn oil, bean oil, grapeseed oil, jojoba oil, palm oil, cotton seed oil, almond oil, safflower oil, walnut oil, avocado oil, rice bran oil, and flaxseed oil.

16. The material of claim 11, wherein the layer (a) has a thickness of 0.05-0.30 mm, and/or the layer (b) has a thickness of 0.20-1.50 mm, and/or the layer (c) has a thickness of 0.05-0.20 mm, and/or the layer (d) has a thickness of 0.20-0.50 mm.

17. A process for obtaining the layered material of claim 10 comprising the following steps: a) depositing a first layer of waterborne polyurethane onto a support; b) drying the polyurethane of step a) at a temperature between 100-120 C. for 1-10 minutes; c) adding to the dry polyurethane of step b) a layer of the composition comprising persimmon; d) drying of the two layers at a temperature between 70-150 C. for 5 minutes to 2 hours; e) adding a third layer of waterborne polyurethane with adhesive properties on the layer comprising persimmon dried in step d), and optionally adding a textile layer above the adhesive layer of step e); f) drying at a temperature between 100-150 C. for 1-5 minutes;

18. The process according to claim 17, wherein the support of step a) presents a pattern to impress said pattern onto the top layer (a).

19. An article comprising the vegan leather material according to claim 10.

20. The article of claim 19 which is selected from a textile product, a footwear product, a leather good, a bookbinding, a frame, a bag, furniture, a watch strap, a cover, a bracelet, a handle, a basket, a key ring or a mask.

21. (canceled)

Description

DESCRIPTION OF FIGURES

[0068] The following figures illustrate the present invention and should not be construed as limiting said invention in any way.

[0069] FIG. 1. Manufacture of a leather-type material of vegetal origin. A. Gelatinization of corn starch in water. B. Plasticization of the gelatinized corn starch. C. Thermo-plastic gel.

[0070] FIG. 2. Layer of the composition in a mold with leather texture. A. Zenith view. B. Lateral view.

[0071] FIG. 3. Leather-type material of vegetal origin obtained by the process of the invention.

EXAMPLES OF THE INVENTION

[0072] The invention is illustrated in the examples, as well as in the figures and generic schemes. The substituents and integers used in the follow schemes are as defined in the embodiments of the instant invention, unless otherwise indicated. This section is set forth to aid in an understanding of the invention but should not be construed to limit in any way the invention as set forth in the claims.

Example 1: Manufacturing of a Vegan Leather from Persimmon and a Polymer Derived from Starch and a Polyol of Vegetable Origin

[0073] Pieces of brilliant red variety of persimmon from the area Ribera del Xquer in Valencia (Spain) were collected. The fruits were blended and frozen at 20 C. until its use. The persimmons were defrosted, and the mass was obtained. The fruit mass being used for producing the leather may be persimmon in the form of puree by crushing mechanically the fruit pieces, the residue from a Soxhlet extraction of the persimmon fruit, the fruit pulp or a combination thereof. In the present example persimmon puree was used. The mass was weighted and reserved. 10 g of corn starch were dissolved in 62.5 g of distilled water at 80 C. under continuous stirring until a gel was formed at 70-80 C. The solution was maintained at this temperature for 30 minutes until a nearly translucent gel was formed. FIG. 1A shows the aspect of the cornstarch granules dissolved in water. 5 g of glycerol were added to the solution while stirring and maintaining the heating at 70-80 C. for approximately 10 minutes. At this moment, the gelation process starts, the stirring speed is increased so that the formation of lumps is avoided (for example 2500 rpm), and the mixture was maintained at 80 C. under continuous stirring for 10 minutes with a hand blender. FIG. 1B shows the gelatinized corn starch after glycerol has been added. The stirring continued under heating until the complete gelation of the starch molecules was produced. This moment was identified because the mixture acquired a homogeneous and translucent aspect (FIG. 1C). All the starch granules have completely turned into the translucent gel phase, which was called glycerol pseudo-plastic starch (GTPS) or plasticized starch. Once the uniform GTPS was produced, this product was weighted. 22 g of persimmon mass was added to 77.5 g of plasticized starch. In this step, 0.5 g of the dye charcoal was also added in order to get a final black color. Addition of the dye only has the purpose of provide the final material the desired color and it is not an essential ingredient in the mixture. The mixture was blended continuously until complete homogenization, obtaining a composite. Complete homogenization is important on order to have a uniform particle size. Once the mixture was fully homogenized, it was added to a mold having a pattern that simulates that of animal leather. FIG. 2 shows a mold with leather texture and the composite.

Example 2: Manufacturing of a Coated Vegan Leather from Persimmon and a Starch-Derived Polymer

[0074] A layer of 100% cotton fiber was placed on top, over the composite obtained in example 1. After assemblance, the sandwich was introduced in a Forced air-drying oven. Afterwards, the sandwich was placed at room temperature for 24 additional hours. Finally, the material was taken out from the mold. FIG. 3 shows the leather-type material obtained after the process. The appearance was identical to leather of animal origin. In order to obtain a protected material with waterproof properties, a layer of coating was added to the material obtained in Example 1. Natural bee wax was mixed with olive oil in 1:1 ratio (w/w) under heating at 40 C. until the wax was fully dissolved. The solution was cooled down and applied uniformly to the leather-type material. After 2 minutes in an oven at 70 C. the excess of coating was removed, and the material was dried again for 2 minutes at 70 C. An additional layer of mixture was added, and the process was repeated.

Example 3: Manufacturing of a 4-Layer Vegan Leather from Persimmon and a Starch-Derived Polymer

[0075] To expand the use of the material of the invention, it was developed a version of the leather-like material formed by 4 layers. Waterborne polyurethane was added to an embossing paper, and it was cured for 2 minutes at 100 C. Waterborne polyurethane is >47% bio based. After this layer was dried, a layer of the material obtained in Example 1 was added on the polyurethane layer (top layer), and both layers were cured for 1 hour and 30 min at 70 C. After drying, an adhesive layer of waterborne polyurethane adhesive was added on the layer comprising persimmon (medium layer) and finally a 100% cotton textile layer were added. The structure with the four layers was cured for 2 minutes at 100 C. Once the material was completely dried, the embossing paper was removed. This material was engineered to simulate the structure of leather as multilayer material. The textile support (100% cotton) fulfils the mechanical function, the middle layer comprising persimmon is the responsible of the feel and softness of the final material, but also of the flexibility and mechanical resistance of the polyurethane upper layer. Table 1 discloses the distribution of the layers of the material and the percentage of biobased element in the final material:

TABLE-US-00001 TABLE 1 Thickness % Biobased % biobased Layer (mm) g/m.sup.2 % wt. per layer final Polyurethane (top layer) 0.10 89.25 17.02 >47 >7.99 Persimmon (medium layer) 0.30 197.65 37.70 100 37.70 Adhesive 0.05 40.00 7.63 >50 >3.81 Textile (bottom layer) 0.30 197.37 37.65 100 37.65 FINAL MATERIAL 0.75 mm 524.27 100% >87.15

[0076] From this table it may be concluded that the total bio-based content in the material is above 85%.

Example 4: Characterization of the Layered Vegan Leather

[0077] The mechanical properties of the material of Example 3 were compared with commercial materials of animal origin. There were chosen two tests to determine abrasion resistance and colour fastness to cycles of to-and-fro rubbing. the determination of the abrasion resistance was performed by the standard method EN 13520:2001/A1:2004). This method was performed in a Martindale abrasion tester at a testing pressure of 12 Pa. Table 2 shows the result of the assay. The results indicated that the material of the invention passed the abrasion resistance test, as other commercial leather, which makes this material suitable for clothing and manufacturing of goods.

TABLE-US-00002 TABLE 2 Leather type No turns Observations Pass Invention 1800 No visual change Yes 3200 Light removal of coating layer Yes 6400 Moderate removal of coating layer. Yes Dry change in color 4. Full grain (*) 1600-6400 No damage or color loss 4 gsr Yes Nubuck/Split/Suede (*) 1600 No damage or color loss 4 gsr Yes Pony skin (*) 800 No damage or color loss 4 gsr Yes (*) Commercially available

[0078] The color fastness was determined according to ISO 11640:2018). This method is referred on how a leather should behave in the test with pieces of standard wool with a given number of forward and backward motions. The change in colour during the test is assessed with a standardized grey scale. Any other visible change or damage of the surface of the leather should be also reported when this test is performed. The value should be A value of 5 it's the best and the greatest grade and any lower value indicates a change in colour. Commercial brands and manufacturers require a value in this test of at least 4 at the end of the cycles. Table 3 shows the results of the test. In this case, the material of the invention had a behaviour similar to the animal leather and at 6400 cycles it showed a grade of 4 and a slight removal of the coating which are both accepted in textile industry.

TABLE-US-00003 TABLE 3 Damp stanning Dry change change Leather type Stanning in color in color Pass Invention 5 (150 5 (150 5 (50 5 (50 Yes cycles) cycles) cycles) cycles) Footwear UPPER (*) Foot contact/non- Foot contact side test: Yes contact side of 50 cycles, 3 on the foot test: 100 grey scale Leather Full grain (*) 4 (150 cycles) 4 (30 cycles) Yes hides Nubuck/Split/Suede (*) 3 (100 cycles) 3 (20 cycles) Yes Pony skin (*) 4 (50 cycles) 3 (10 cycles) Yes (*) Commercially available

[0079] When the leather is for directed to an item in foot contact or non-contact side of foot, the standard is performed at 100 cycles and at 50 cycles with a maximum grade required for a pass of equal or higher to 3 in the grey scale. The results above show the grade of each material after several cycles are the average results. The material of the invention obtained a score of 5 in all tests with 150 cycles instead of 100 in the other materials or 50 cycles instead 10-50 cycles in the other materials. These results indicate that the material of the invention has a very good performance, even better than other commercial leathers. These results show that the performance of the material of the invention comply with two of the most important tests required by natural leather manufacturer and designers.

Example 5: Manufacturing of Vegan Leather from Persimmon and PU Formed from Isocyanates and Polyols of Vegetable Origin

[0080] The persimmon pure was obtained as described in Example 1.48 g of this persimmon mass was mixed with 46 g of a PU of natural origin and the mixture was stirred. During the stirring, 5 g of soja oil and 1 g of a natural pigment were added to the mixture, and the stirring was maintained for 5-10 min. For the manufacturing of the multilayer vegan leather material, a mixture of waterborne PU with additives is added on an embossing paper which gives the texture to the final top layer, obtaining a layer with a thickness of less than 200 micrometers. This layer is dried by passing through ventilated ovens at a T above 100 C. for a couple of minutes, to obtain the top layer. Then, the mixture based on persimmon mass previously obtained is added on this dried top layer. The application is with continuous and slow flow and can be with various thicknesses, depending on the interest of the thickness of the final sample. It is dried by passing it through ventilated ovens at a T above 100 C. A bio-based PU adhesive is prepared and spread on the dried persimmon layer together with an organic support, in this case a cotton cloth. The two layers are pressed together and then placed in the ovens for a couple of minutes to dry. Finally, the product is cured in oven at a temperature of 135-140 C. during 3-5 min. In the obtained material, layer (a) represents 11% wt., layer (b) 51% wt., layer (c) 8% wt. and layer (d) 30% wt. in respect to the total weight of the layered material.

Example 6: Study of the Physical-Mechanical Properties of the Vegan Leather Layered Material from Persimmon and PU

[0081] The purpose of this study is the comparison between the properties of the vegan material of the invention and products existing on the market as shown in the following tables:

TABLE-US-00004 TABLE 4 standardized test used for measuring each property Measured Property Test Equivalent Thickness (mm) ISO 17186-A ASTM D1813 Laminar mass for area unit (g/m.sup.2) UNE-EN ISO 2286-2: 2017 ASTM D3776 Determination of breaking UNE-EN ISO 3376: 2011 strengthand (N/mm.sup.2) Determination of elongation UNE-EN ISO 3376: 2011 strengthand (%) Determination of tear resistance (N) UNE-EN ISO 3377-2: 2016 ASTM D4704 Determination of transmission of UNE-EN ISO 14268: 2012 water vapour (mg/(cm.sup.2*h) Resistance to flexion (cycles) of the UNE-EN ISO 5402-1: 2012 ASTM 6182 coated side Colour fastness to artificial light UNE-EN ISO 105-B02: 2014 (Note of 1 to 8) Determination of the abrasion UNE-EN ISO 13520:2001/A1: 2004 ASTM D3886 resistance of fabrics (cycles) Colour fastness to cycles of to-and-fro UNE-EN ISO 11640: 2013 AATC 8, Flat rubbing (Note 1 to 5 Dry-Wet)

TABLE-US-00005 TABLE 5 results for test applied to naturally grown materials Measured Property Leather Muskin Kombucha Thickness (mm) 1.93 6.22 0.29 Laminar mass for area unit (g/m.sup.2) Determination of breaking strengthand (N/mm.sup.2) 39.5 0.2 9.7 Determination of elongation strengthand (%) Determination of tear resistance (N) 82.9 0.5 5.1 Determination of transmission of water 4.6 10.4 0.1 vapour (mg/(cm.sup.2*h) Resistance to flexion (cycles) of the coated 200 10,000 10,000 side Colour fastness to artificial light Determination of the abrasion resistance of fabrics (cycles) Colour fastness to cycles of to-and-fro rubbing

TABLE-US-00006 TABLE 6 results for test applied to different coated textiles PUR Vegan leather coat Teak Fruit of the invention Property tex. Desser A leskin V Leaf N works Leather ( ) Thickness (mm) 1.37 0.88 1.14 0.95 0.57 1.065 1.05 1.32 mass for area 453 794 unit (g/m.sup.2) Determination of 10.2 20.8 14 9.4 12.2 7.74 8.27 breaking strengthand (N/mm.sup.2) Determination of 49.2 26.74 elongation strengthand (%) Determination of tear 17 37.2 18.4 16.6 30.7 53.6 19.38 61.68 resistance (N) Determination of 200,000 30,000 50,000 50,000 100 100,000 10,000 >300,000 transmission of water vapour (mg/(cm.sup.2*h) Resistance to flexion 6-7 (cycles) of the coated side Colour fastness to 1,300 25,600 artificial tight Determination of the 5 4 5 abrasion resistance of fabrics (cycles) Colour fastness to 4 3 4-5 cycles of to-and-fro rubbing indicates data missing or illegible when filed

TABLE-US-00007 TABLE 7 results for test applied to non-woven of plant material Measured Property Pinatex SnapPap Thickness (mm) 1.43 0.57 Laminar mass for area unit (g/m.sup.2) Determination of breaking strengthand 4.5 24.9 (N/mm.sup.2) Determination of elongation strengthand (%) Determination of tear resistance (N) 31 7.5 Determination of transmission of water vapour 2.5 10.3 (ma/(cm.sup.2*h) Resistance to flexion (cycles) of the coated 150,000 5,000 side Colour fastness to artificial light Determination of the abrasion resistance of fabrics (cycles) Colour fastness to cycles of to-and-fro rubbing

[0082] Regarding the thickness, it can be seen that there are products which have a greater thickness and other products less, so the vegan leather of the invention is in line of similar products, 36% of the competition are with values above and 64% below.

[0083] The laminar mass is a very important property in terms of physical parameters of the products, and it depends on the textile substrate used and the intermediate layer of persimmon deposited.

[0084] The tensile strength test evaluates the resistance of the fabric itself when subjected to a certain force until it breaks. As can be seen in the results, the breaking strength value of the vegan leather of the invention is also in line with many of the results of the competition: 45% of the competition are with values above and 55% below. The resistance to elongation can only be compared with that obtained by Fruit Leather. As can be seen in this case, the value of the fruit leather is higher, although a value of 26.74% obtained by the vegan leather of the invention is already a more than acceptable value for the clothing market that is the market that most requires this property.

[0085] The tear resistance is a property that has a greater importance in the market of fashion clothing, upholstery, contract and footwear. In this case the value obtained by the vegan leather of the invention is much higher than the rest of the products, only being surpassed by that of natural skin.

[0086] The test of water vapor permeability determines the breathability of the product, which is a relevant property in the clothing market. The value of breathability compared to natural skin is 85% lower although, compared to the rest of the products, 45% is with higher values and 55% with lower values, so it can be said that the vegan leather of the invention is in line with the results of the other commercial products.

[0087] The results obtained in the flexural strength test are very favorable for the vegan leather of the invention, since they are higher than the values of the other products, being at the same level as a natural animal skin.

[0088] This color fastness to artificial light test determines the resistance of the products to color degradation by continuous exposure to artificial light, having this property a greater impact on the automotive and contract markets.

[0089] The vegan leather of the invention was only compared with Fruit Leather and can be seen that the values for the vegan leather of the invention are clearly between 125-150% in terms of color resistance. According to Standard UNE-EN 14465:2004/A1 within the levels of behavior from A to E, the vegan leather of the invention would be at a level A, which is very favorable for the upholstery, automotive and contract market.

[0090] The abrasion resistance property has greater incidence in the markets of footwear or upholstery. The value of this property was only measured for the vegan leather of the invention and, according to Standard UNE-EN 14465:2004/A1 within the levels of behavior from A to E, this product would be at a level B, which is very favorable for the upholstery market.