Multi-layered flexible material comprising organic content, method of obtaining and uses thereof

Abstract

The present disclosure relates to a photo-resistant flexible multi-layered material comprising: a layer comprising a polymeric matrix and an organic material, wherein the organic material is impregnated with an iron oxide; and a transparent cover layer, wherein the cover layer is a lacquer, a polymeric layer or combinations thereof; wherein the layers are bounded to each other. An article comprising the photo-resistant flexible multi-layered material as described, as well as the use of iron oxide as a protector of discoloration by light of an organic material, wherein the iron oxide is impregnated in the organic material, are also disclosed.

Description

D E S C R I P T I O NMULTI-LAYERED FLEXIBLE MATERIAL COMPRISING ORGANIC CONTENT, METHOD OF OBTAINING AND USES THEREOFTECHNICAL FIELD

[0001] The present disclosure relates to a stable multi-layered material comprising a visible organic material.BACKGROUND

[0002] The incorporation of organic content, such as wood, or cork, in vehicle materials has been the target of a great market demand. However, this causes some functional and aesthetic problems, mainly due to the colour modification of the article after exposure to long periods of solar radiation. Thus, one of the major challenges is to keep the aesthetic aspect of the article without compromising its properties / functional requirements.

[0003] The mechanism of decomposition of natural polymers by solar radiation is very complex. Sunlight can depolymerize components such as cellulose, hemicellulose and lignin. Considering its chemical composition, lignin is pointed out as the key cause of photo-degradation of natural fibers. This is because, of its main constituents, cellulose, hemicelluloses and lignin, lignin absorbs more strongly in the UV / visible Region, and it is a good absorber of sunlight due to the presence of several groups (carbonyl, double bond aromatics, phenolic hydroxyl, etc.).

[0004] Lignin is the main chemical constituent responsible for the photo-degradation of wood, and it is believed to be in other organic content as well. This is due to the high number of chromophores present in the structure of lignin, as well as double bonds, carbonyl groups and hydroxyl groups. This becomes a critical problem when incorporating organic material, such as cork, especially in areas of greater exposure to sunlight, since lignin suffer oxidation. Light and heat induced oxidation of organic materials is a complex radical process characterized by initiation, propagation, chain branching, autocatalytic chain autocatalytic chain, and termination. The initiationreaction of photo-oxidation, starts when a chromophore (CH) absorbs radiation energy, becoming highly reactive, giving rise to free radicals (R •). Under the influence of heat, photo-oxidation can become faster, through thermo-oxidation. The free radicals formed during the photo-oxidation and thermo-oxidation processes react with oxygen to form peroxide radicals (ROO»), which attack the polymer (P-H) giving rise to unstable hydroperoxides (ROOH). These hydroperoxides fragment due to UV radiation and / or heat, forming additional free radicals, continuing the cycle. The photo-oxidation process results in the discoloration of the material. The thermal degradation depends strongly on the temperature, which results in different percentages of mass loss.

[0005] In order to avoid photo degradation of materials such as wood, different protective systems have been developed.

[0006] To reduce the degradation process, usually a pigmented opaque top layer is added to the wood to absorb the incident UV radiation and dissipate it as heat before the radiation reaches its surface. However, the natural appearance of the wood is hidden under the coating.

[0007] Photo-stabilizers are also typically added to transparent coatings to maintain the natural appearance of wood and offer good protection against sunlight. Usually, a combination of two different types of substances is used: UV absorbers and hindered amine light stabilizers (HALS). HALS do not absorb UV radiation, but act to inhibit degradation of the polymer by continuously and cyclically removing free radicals that are produced by photo-oxidation of the polymer.

[0008] Another alternative is to combine a small amount of inorganic UV absorbers with an excess of organic UV absorbers in wood and cork in the form of a coating. Inorganic UV absorbers are ideally nanoparticulate materials - called mineral filters (MS) - such as titanium dioxide (TiO2), zinc oxide (ZnO) or cerium oxide (CeO2). Mineral nanoparticles absorb and reflect the spectra of UV and visible (VIS) radiation. The smaller the particle size, the larger the surface area and, consequently, the more effective the UV light spread below 400 nm. Although effective, this method proves to be expensive as it focuses on the combination of organic and inorganic absorbers.

[0009] Mixture of colouring agents in a premix masterbatch with other premix or master-batch including carbon black, polymer phase and wood particles has also been reported as an alternative treatment.

[0010] The present disclosure relates to a treatment method that allows the maintenance of the aesthetic appearance of materials with cork or natural fibres after exposure to sunlight.

[0011] Document W02007051741 discloses a method for protecting cork or wood substrates from discoloration comprising applying to the cork or wood substrate a coating, which coating contains a) an organic UV-absorber; and b) an inorganic UV- absorber selected from the group consisting of transparent iron oxide, transparent titanium dioxide, transparent zinc oxide, transparent cerium oxide and carbon black or mixtures thereof; wherein the weight ratio of organic UV-absorber to inorganic UV- absorber is from 1000:1 to 10:1. However, the document is silent on the impregnation (as opposed to coating) of organic material with an iron oxide to protect from discoloration caused by light exposure.

[0012] These facts are disclosed in order to illustrate the technical problem addressed by the present disclosure.GENERAL DESCRIPTION

[0013] The present disclosure relates to a method of pre-treatment of materials of natural origin, such as natural fibres or cork, before its inclusion in synthetic polymeric matrices, through pigmentation with iron oxide. The stability of these materials is further enhanced by the addition of UV absorbers.

[0014] The flexible multilayer material described in the present disclosure comprises a polymeric matrix comprising a visible organic material impregnated with an iron oxide, thereby allowing for an increase in the quality of the material and the durability of the product with the desired quality, even after subjecting the product to several cycles of flexure degradation under extreme extraction and temperature conditions. Surprisingly, the aesthetic aspect of the article was kept after the disclosed treatment, while theproperties / functional requirement of the articles were still maintained namely the aging resistance of the material.

[0015] An aspect of the present disclosure relates to a flexible multilayer material with an appropriate touch in order to be suitable to be use in a vehicle, namely upholstery, that fulfil all the requirements of automotive industry namely crack resistance, aging resistance, UV resistance among others.

[0016] The present realizations are useful for materials with organic content whose applications involve exposure to solar radiation as it maintains the natural appearance of the organic content even after exposure to this radiation.

[0017] The solution presented in the present description is based in particular on the fact that iron oxide is a semiconductor. In semiconductors, the electrical conductivity is due to the movement of free charge carriers in the solid. These carriers can be electrons, in the empty conduction band, or holes, in the valence band. The semiconductors can be p-type or n-type. In the p-type is mainly due to the holes, while in an n-type semiconductor, it involves electrons. A material to be considered a semiconductor must have a separation between the valence band and the conduction band of less than 5 eV. This energy difference between the valence band and the conduction band is defined as the energy gap. This value determines the region of the solar spectrum that the material is capable of absorbing, that is, a smaller energy gap allows the absorption of radiation with longer wavelengths. Iron oxide has a relatively low value, more specifically, about 2.2 eV. This means that absorbs at wavelengths shorter than 564 nm, i.e., it absorbs UV radiation as well as a part of the visible one. Besides that, iron oxide is an abundant, stable component in nature.

[0018] The present disclosure relates to a photo-resistant flexible multi-layered material comprising: a layer comprising a polymeric matrix and an organic material, wherein the organic material is impregnated with an iron oxide; and a transparent cover layer, wherein the cover layer is a lacquer, a polymeric layer or combinations thereof; wherein the layers are bounded to each other. The organic material is visible at the surface.

[0019] The photo-resistance of the flexible multi-layered material of the present disclosure is surprisingly achieved through the specific resistance to UV radiationprovided by the organic particles containing iron oxide. This unique composition allows the material to withstand external conditions without undergoing photo-degradation. As a result, the material of the present disclosure maintains its appearance and mechanical properties over time, improving the aging of the material even with the decrease of density. This achievement is possible to view in Figures 3 and 4 which illustrate the before and after comparison with cork and without treatment.

[0020] In an embodiment, the transparent cover layer comprises: an organic UV absorber (UVA), a hindered amine light stabilizer (HALS), or mixtures thereof. Preferably, a blend of hydrophilic 2-(2-hydroxyphenyl)-benzotriazole UVA and a HALS.

[0021] In an embodiment, the iron oxide is hematite or an iron oxide pigment.

[0022] In an embodiment, the iron oxide pigment is selected from red iron oxide pigment, brown iron oxide pigment, yellow iron oxide pigment, black iron oxide pigment or orange iron oxide pigment.

[0023] In an embodiment, the polymeric matrix is a matrix of polyvinyl chloride, polyurethane, thermoplastic elastomer, or combinations thereof.

[0024] In an embodiment, the UV absorber is selected from a list comprising benzotriazole, benzophenone, oxanilide, hydroxyphenyltriazine and mixtures thereof.

[0025] In an embodiment, the hindered amine light stabilizer is selected from a list comprising decanedioic acid, bis (2,2,6,6-tetramethyl-l-(octyloxy)-4-piperidinyl) ester; Tetramethyl piperidine derivative; N,N'-Bis(l,2,2,6,6-pentamethyl-4-piperidinyl)-l,6- hexanediamine; l,3,5-Tris(2-hydroxyethyl)-2,4,6-trimethyl-2,4,6-tris(3,5-di-tert-butyl- 4-hydroxybenzyl)benzene; 2,2,6,6-Tetramethyl-4-piperidinyl stearate; Bis(2, 2,6,6- tetramethyl-4-piperidinyl)sebacate; Mixture of diester of l,4-bis((2,2,6,6-tetramethyl-4- piperidinyl)oxy)-2,5-hexanedione and l,2-bis(3,5-dimethyl-2-hydroxybenzyl)-2, 2,6,6- tetramethyl-4-piperidinyl bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate; Mixture of (1- (Methyl)-8-(l,2,2,6,6-pentamethyl-4-piperidinyl)3,8-diazaspiro[4.5]decan-2-one and 1- (Methyl)-8-(l,2,2,6,6-tetramethyl-4-piperidinyl)3,8-diazaspiro[4.5]decan-2-one).

[0026] In an embodiment, the organic material is selected from cork, wood, hemp, linen, kenaf, jute, or combinations thereof; preferably cork.

[0027] In an embodiment, the amount of organic material in the multi-layered material ranges from 0.02-50 g / m2, preferably from 0.1 to 17.5 g / m2.

[0028] In an embodiment, the amount of organic material in the multi-layered material ranges from 0.3 to 16 g / m2, preferably from 1.5 to 5.5 g / m2.

[0029] In an embodiment, the organic material comprises 0.02 to 17.5 g / gCOrk of iron oxide, preferably 0.2-5.5 g / gcork of iron oxide.

[0030] In an embodiment, the photo-resistant flexible multi-layered material further comprises a top lacquer layer.

[0031] In an embodiment, the photo-resistant flexible multi-layered material further comprises a bottom support layer, preferably a bottom textile layer.

[0032] In an embodiment, the grammage of the polymeric layer is less than 150g / m2.

[0033] In a further embodiment, the grammage of the polymeric layer ranges from 50- 100 g / m2.

[0034] In the state of the art, the grammage may be measured by many methods. In the present disclosure, the grammage was measured following the ISO 2286-2, item 3:2016.

[0035] In an embodiment, the polymeric layer comprises polyvinyl chloride, polyurethane, or thermoplastic elastomer.

[0036] In an embodiment, the photo-resistant flexible multi-layered material further comprises a foam layer.

[0037] In an embodiment, the grammage of the foam layer ranges from 100-350 g / m2, preferably from 150-250 g / m2.

[0038] In an embodiment, the multilayer material is flexible according to standard VDA 230-225:2014.

[0039] In an aspect the present disclosure relates to an article comprising the disclosed photo-resistant flexible multi-layered material, preferably wherein said article is an upholstery article, or a seat, or door panel, or a vehicle interior trim, preferably an automotive interior trim.

[0040] The present disclosure also relates to the use of an iron oxide as a protector of discoloration by light of an organic material, wherein the iron oxide is impregnated in the organic material. In a further embodiment, the mass ratio between the organic material and iron oxide ranges from 0.05-50 (giron oxide / gcork).

[0041] These facts are described in order to illustrate the technical problem addressed by the present invention.BRI EF DESCRI PTION OF THE DRAWI NGS

[0042] The following figures provide preferred embodiments for illustrating the disclosure and should not be seen as limiting the scope of invention.

[0043] Figure 1: Schematic representation of an embodiment of an article prepared with cork treated by the disclosed method using hematite.

[0044] Figure 2: Schematic representation of an embodiment of an article prepared with cork treated by the disclosed method using iron oxide pigment.

[0045] Figure 3: Embodiment of results of a polyvinyl chloride (PVC) film comprising a compact layer with 3.5g / m2of natural cork, before and after the lightfastness test with 5 cycles.

[0046] Figure 4: Embodiment of a PVC film comprising a compact layer with 3.5 g / m2of natural cork and a polyurethane (PUR) pre-skin on top of said compact layer, before and after the lightfastness test with 5-cycles.

[0047] Figure 5: Embodiment of a PVC film comprising a compact layer with 3.5g / m2of natural cork treated with 2% (w / w) of hematite, and a PUR pre-skin, before and after 5 cycle lightfastness test.

[0048] Figure 6: Embodiment of a PVC film comprising a compact layer with 3.5g / m2of natural cork treated with 2% (w / w) of hematite, and lacquers comprising HALS or UV absorbers, before and after 5 cycle lightfastness test.

[0049] Figure 7: Embodiment of a PVC film comprising a compact layer with 5g / m2of natural cork treated with 0.25% (giron oxide pigment / gcork) and a PVC pre-skin, before and after 5 cycle lightfastness test.

[0050] Figure 8: Embodiment of a PVC film comprising a compact layer with 5g / m2of natural cork treated with 0.75% (giron oxide pigment / gcork) and a PVC pre-skin, before and after 5 cycle lightfastness test.

[0051] Figure 9: Embodiment of a PVC film comprising a compact layer with 5g / m2of natural cork treated with 0.75% (giron oxide pigment / gcork) without a PVC pre-skin, before and after 5 cycle lightfastness test.

[0052] Figure 10: Embodiment of Scanning electron images of cork treated with hematite (0.5% (w / w), 1% (w / w) and non-treated cork (cork + water).

[0053] Figure 11: Embodiment of results of EDS analysis of a surface of the disclosed flexible layer material 1) PVC comprising cork impregnated with 1% (w / w) of hematite at 80 °C; 2) PVC comprising cork impregnated with 1% (w / w) of hematite at room temperature.DETAILED DESCRI PTION

[0054] The present disclosure relates to a photo-resistant flexible multi-layered material comprising: a layer comprising a polymeric matrix and an organic material, wherein the organic material is impregnated with an iron oxide; and a transparent cover layer, wherein the cover layer is a lacquer, a polymeric layer or combinations thereof; wherein the layers are bounded to each other. An article comprising the photo-resistant flexible multi-layered material as described, as well as the use of iron oxide as a protector of discoloration by light of an organic material, wherein the iron oxide is impregnated in the organic material, are also disclosed.

[0055] In an embodiment, the construct comprises a transparent cover layer comprising a surface layer with a lacquer and UV absorbers and a translucent polymeric layer (preskin) of PUR or PVC; a layer, preferably a compact layer, comprising a polymeric matrix and an organic material, wherein the organic material is impregnated with an iron oxide; and a foam layer, that allows adhesivity to the textile (Figure 1 and Figure 2).

[0056] In an embodiment, the organic material is impregnated with an iron oxide, preferable iron oxide pigment, by mixing said organic material and an iron oxide solution prepared using a suitable solvent such as water or methyl ethyl ketone (MEK). Thesolvent is then evaporated from the organic material, resulting in an organic material impregnated with the iron oxide.

[0057] In an embodiment, the organic material is impregnated with hematite, using a solution of hematite in water. The organic material and the hematite solution are mixed at a temperature between 20 to 80 °C, preferably 20 to 40°C, and then dried at a temperature between 20 to 80 °C, preferably 80°C. Optionally, the hematite solution is filtered before being mixed with the organic material.

[0058] In a further embodiment, 300 g of cork is mixed with 99g of hematite and 12 litres of water (0.33 ghematite / gcork). The mixture is prepared at room temperature or at 80°C, using a mixer at a constant speed of 80 rpm. Preferably, the water is previously filtered to ensure drying at 80°C. Finally, the mixture is dried at 80°C until the water evaporates completely.

[0059] For the scope and interpretation of the present disclosure it is defined that "room temperature" should be regarded as a temperature between 15-30 °C, preferably between 18-25 °C, more preferably between 20-22 °C.

[0060] In another embodiment, the organic material is mixed with a pigment containing iron oxide, and a suitable solvent, such as MEK. Then, MEK is evaporated at room temperature. Optionally, the resulting material is further washed with MEK, filtered and dried. Results regarding the colour change of the obtained materials after light fastening test (5 cycles) are presented in Table 1 and represented in Figure 7, Figure 8 and Figure 9.Table 1 - Light fastening results obtained with cork treated with pigment.

[0061] In a further embodiment, 300 g of cork are mixed with 75g of pigment and MEK, to promote the mixture (0.25 gpigment / gcork). This mixture can be dried at room temperature for evaporation of the MEK.

[0062] Surprisingly, after the disclosed treatment, the organic material was still visible on the construct, and kept its appearance over time after exposure to UV radiation (Figure 5 and Figure 6), as opposed to the control samples (PVC film comprising a compact layer with 3.5 g / m2of natural cork (Figure 3); or PVC film comprising a compact layer with 3.5 g / m2of natural cork and a PUR pre-skin on top of said compact layer (Figure 4)).

[0063] In an embodiment, lightfastness was tested using the standard DIN EN ISO 105- B06:2020, for 5 cycles. The lightfastness test simulates the aging that the articles experience when exposed to sunlight, allowing the assessment of their resistance to UV radiation exposure. The evaluation was then assessed using the grayscale as defined in standard EN 20105-A02:94 for determining changes in colour of textiles in colour fastness tests, where the lightfastness is rated between 1-5, 1 being very poor and 5 being excellent lightfastness.

[0064] In an embodiment, the treatment involving pigmentation with hematite requires the addition of water. In order to understand if this addition could potentiate the discoloration of the material, light fastness tests were performed on two control samples comprising a polymeric matrix (PVC) and an organic material (cork): PVC + Cork and PVC + cork + water. The organic material was mixed with the PVC paste, for 5 to 30 minutes using a mixer at 500 to 2500 rpm. After mixing, the obtained mixture was processed to produce a layer. Different methods can be used to obtain a PVC layer, such as deposition, knife coating, extrusion. After the light fastness tests, it was found that the addition of water had no influence on the UV / Vis resistance, and both samples obtained the worst result of colour change, according to the grayscale.

[0065] In an embodiment, the organic material was impregnated with different mass fractions of hematite.

[0066] In an embodiment, cork was impregnated with hematite, and subsequently added to a PVC paste. The resulting mixture was processed using suitable methods to obtain a polymeric layer. This layer was further coated with a polymeric transparent cover layer (pre-skin), made of PVC, PUR, or TPE or its mixtures. Said pre-skin is transparent, has a grammage of less than 150g / m2, and comprises hindered amine light stabilizers (HALS). These samples were compared against PVC + natural cork + pre-skin, i.e., against samples where the organic material (cork) was not impregnated with an iron oxide (hematite). In order to determine the influence of the amount of hematite applied on the treatment efficacy, samples with different mass fractions of hematite - 0.25% (w / w), 0.5% (w / w), 1% (w / w), 2% (w / w) - were tested.

[0067] In an embodiment, HALS are selected from a list comprising Decanedioic acid, bis (2,2,6,6-tetramethyl-l-(octyloxy)-4-piperidinyl) ester; Tetramethyl piperidine derivative; N,N'-Bis(l,2,2,6,6-pentamethyl-4-piperidinyl)-l,6-hexanediamine; 1,3,5- Tris(2-hydroxyethyl)-2,4,6-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4- hydroxybenzyl)benzene; 2,2,6,6-Tetramethyl-4-piperidinyl stearate; Bis(2, 2,6,6- tetramethyl-4-piperidinyl)sebacate; Mixture of diester of l,4-bis((2,2,6,6-tetramethyl-4- piperidinyl)oxy)-2,5-hexanedione and l,2-bis(3,5-dimethyl-2-hydroxybenzyl)-2, 2,6,6- tetramethyl-4-piperidinyl bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate; Mixture of (1- (Methyl)-8-(l,2,2,6,6-pentamethyl-4-piperidinyl)3,8-diazaspiro[4.5]decan-2-one and 1- (Methyl)-8-(l,2,2,6,6-tetramethyl-4-piperidinyl)3,8-diazaspiro[4.5]decan-2-one).Table 2 - Light fastening results obtained with cork treated with hematite.

[0068] The results, presented in Table 2, show that the impregnation of the organic material into a solution of hematite with increasing concentration resulted in better light fastening properties, for solutions with concentrations up to 1% (w / w) in hematite. Without being bound to any theory, it is hypothesized that this is due to the fact that the cork reaches its saturation point for 1% (w / w) hematite, i.e., does not possesscapacity to impregnate more hematite above this concentration. This theory corroborates an observation of colour alteration of the PVC paste when pigmented cork (i.e., cork impregnated with hematite) is added with fractions of hematite equal to or greater than 1% (w / w).

[0069] Surprisingly, the data shown in Table 2 shows that all samples treated with hematite obtained a degree of colour change equal or greater than 3 when these were exposed to 5 cycles of exposure to light for 60 h. These are in agreement with the minimum requirement of the light fastness test, which requires a degree of colour change of 4 for 3 cycles of exposure to light for 60 h

[0070] In another embodiment, the results show that the singular use of pre-skin containing HALS is not sufficient to provide UV / Vis protection to cork. However, its combination with the disclosed treatment involving cork pigmentation by impregnation with an iron oxide proves to be an innovative and effective method for UV / Vis protection of PVC film containing cork.

[0071] In another embodiment, a multi-layered material was prepared using a layer of a PVC polymeric matrix comprising natural cork or cork pigmented with different concentrations of hematite, and a layer comprising suitable lacquers, supplemented or not with HALS and UV absorbers. No pre-skin was used in the present embodiment.

[0072] In an embodiment, UV absorbers are selected from a list comprising benzotriazole, benzophenone, oxanilide, hydroxyphenyltriazine, and mixtures thereof.Table 3 - Embodiment of light fastening results for multilayered materials comprising organic material (cork) treated or not with hematite.Reference lacquers - suitable lacquers for PVC constructs, without further supplementation.

[0073] In an embodiment, the results show that the presence of lacquers, regardless of the amount of stabilizer (HALS or UV absorbers) incorporated in them, conferred an increase in UV / Vis protection to the samples, when compared with the pigmented cork sample or even with the films consisting only of cork with or without lacquers.

[0074] Surprisingly, the synergy between the two absorbers (organic and inorganic) occurs, even when the inorganic absorber (hematite) is not in the form of a layer but incorporated by impregnation into the organic material (cork).

[0075] In another embodiment, the three treatments studied were combined, in order to understand if this could increase the UV / Vis protection provided to the polymeric film containing cork. Therefore, multi-layered samples comprising a polymeric layer (PVC) comprising the treated organic material (cork impregnated with hematite), a pre-skin layer of PUR and a layer of lacquer comprising HALS and UV absorbers were tested. The results were compared with control samples: PVC + natural cork + pre-skin; PVC +natural cork + pre-skin + reference lacquers; PVC + natural cork + lacquers with HALS / UV absorbers.Table 3 - Embodiment of light fastening results for multilayered materials comprising organic material (cork) treated or not with hematite.

[0076] In an embodiment, the results from the light fastness test showed that the pigmentation of cork with hematite is essential to confer UV / Vis protection to cork. However, the protection is only effective if the films are coated with the pre-skin or lacquers, since without these the polymeric matrix degrades.

[0077] In an embodiment, the presence of pigment in the organic material can be confirmed by scanning electron microscopy (SEM) coupled with energy dispersive X-rayspectroscopy (EDS). The analysis by scanning electron microscopy (SEM) was carried out on cork samples treated with hematite, to evaluate the uniformity and quality of the impregnation of the hematite particles in the cork (Figure 10).

[0078] Figure 10 shows that hematite can be distinguished in the alveolar structure of the cork by its lighter tone. The image identified with the number 1 allows to observe the alveolar structure of the cork. In image 2, representative of a sample of cork treated with 0.5% (w / w) of hematite, the presence of hematite is already perceptible, although the concentration is small. In Image 3, an increase in the amount of hematite incorporated in the cork alveolar structure is observed, as the sample was prepared with a higher concentration of the iron oxide (1% (w / w) of hematite). However, in Image 4, the same amount of embedded hematite is on the surface of the cork, without penetrating the open alveoli. While Image 1 and 2 are representative results obtained from samples prepared at 80 °C, Image 4 is representative of a sample prepared at room temperature.

[0079] Figure 11 depicts an embodiment of the EDS analysis of the entire surface visible in Figure 10, images 3 and 4. The obtained results shown a higher concentration of hematite in the case of impregnation at room temperature. This fact seems to support the hypothesis that under these conditions there is no penetration of hematite into the open cork voids.

[0080] The term "comprising" whenever used in this document is intended to indicate the presence of stated features, integers, steps, components, but not to preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0081] The disclosure should not be seen in any way restricted to the embodiments described and a person with ordinary skill in the art will foresee many possibilities to modifications thereof. The above-described embodiments are combinable.

[0082] The following claims further set out particular embodiments of the disclosure.

Claims

C L A I M S1. A photo-resistant flexible multi-layered material comprising: a first layer comprising a polymeric matrix and an organic material, wherein the organic material is impregnated with an iron oxide for the organic material to maintain the visibility at an outer surface of the first layer; and a transparent or translucid second layer covering the outer surface of the first layer, wherein the second layer is a lacquer, a polymeric layer or combinations thereof; wherein the layers are bounded to each other.

2. The photo-resistant flexible multi-layered material according to the previous claim wherein a mass ratio between the organic material and iron oxide is 0.05-50%; preferably 10-40%; more preferably 15-30%.

3. The photo-resistant flexible multi-layered material according to the previous claim wherein the transparent or translucid cover layer comprises: an organic UV absorber, a hindered amine light stabilizer, or mixtures thereof.

4. The photo-resistant flexible multi-layered material according to any of the previous claims wherein the iron oxide is hematite or an iron oxide pigment, preferably wherein the iron oxide pigment is selected from red iron oxide pigment, brown iron oxide pigment, yellow iron oxide pigment, black iron oxide pigment or orange iron oxide pigment.

5. The photo-resistant flexible multi-layered material according to any of the previous claims wherein the polymeric matrix is a matrix of polyvinyl chloride, polyurethane, thermoplastic elastomer, or combinations thereof.

6. The photo-resistant flexible multi-layered material according to any of the previous claims 2-4 wherein the UV absorber is selected from a list comprising benzotriazole, benzophenone, oxanilide, hydroxyphenyltriazine and mixtures thereof; and / or wherein the hindered amine light stabilizer is selected from a list comprisingDecanedioic acid, bis (2,2,6,6-tetramethyl-l-(octyloxy)-4-piperidinyl) ester; Tetramethyl piperidine derivative; N,N'-Bis(l, 2,2,6, 6-pentamethyl-4-piperidinyl)- 1,6-hexanediamine; l,3,5-Tris(2-hydroxyethyl)-2,4,6-trimethyl-2,4,6-tris(3,5-di- tert-butyl-4-hydroxybenzyl)benzene; 2,2,6,6-Tetramethyl-4-piperidinyl stearate; Bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate; Mixture of diester of 1,4- bis((2,2,6,6-tetramethyl-4-piperidinyl)oxy)-2,5-hexanedione and l,2-bis(3,5- dimethyl-2-hydroxybenzyl)-2,2,6,6-tetramethyl-4-piperidinyl bis(2, 2,6,6- tetramethyl-4-piperidinyl)sebacate; Mixture of (l-(Methyl)-8-(l,2,2,6,6- pentamethyl-4-piperidinyl)3,8-diazaspiro[4.5]decan-2-one and l-(Methyl)-8- (l,2,2,6,6-tetramethyl-4-piperidinyl)3,8-diazaspiro[4.5]decan-2-one), and mixtures thereof.

7. The photo-resistant flexible multi-layered material according to any of the previous claims wherein the organic material is selected from cork, wood, hemp, linen, kenaf, jute, or combinations thereof; preferably cork.

8. The photo-resistant flexible multi-layered material according to any of the previous claims wherein the amount of organic material in the multi-layered material ranges from 0.02-50 g / m2, preferably from 0.1 to 17.5 g / m2.

9. The photo-resistant flexible multi-layered material according to any of the previous claims wherein the organic material comprises 0.02 to 17.5 g / g of iron oxide, preferably 0.2-5.5 g / g of iron oxide.

10. The photo-resistant flexible multi-layered material according to any of the previous claims further comprising a top lacquer layer and / or further comprising a bottom support layer, preferably a bottom textile layer.

11. The photo-resistant flexible multi-layered material according to any of the previous claims wherein the grammage of the polymeric layer is less than 150g / m2, preferably wherein the grammage of the polymeric layer ranges from 50-100 g / m2.

12. The photo-resistant flexible multi-layered material according to any of the previous claims wherein the polymeric layer comprises polyvinyl chloride, polyurethane, or thermoplastic elastomer.

13. The photo-resistant flexible multi-layered material according to any of the previous claims further comprising a foam layer.

14. The photo-resistant flexible multi-layered material according to any of the previous claims wherein the grammage of the foam layer ranges from 100-350 g / m2, more preferably from 150-250 g / m2.

15. The photo-resistant flexible multi-layered material according to any of the previous claims wherein the multilayer material is flexible according to standard VDA 230- 225:2014.

16. An article comprising a photo-resistant flexible multi-layered material as described in any one of the previous claims 1-15, preferably wherein said article is an upholstery article, or a seat, or door panel, or a vehicle interior trim, preferably an automotive interior trim.

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