Eco-artificial leather using PLA nonwoven fabric as grain layer and manufacturing method therefor

Abstract

The present invention relates to a novel high-quality eco-artificial leather which is environmentally friendly due to high biomass content including PLA and has excellent surface smoothness, flexibility, strength, and the like, and to a method for easily manufacturing the eco-artificial leather. According to the present invention, provided are an eco-artificial leather using a PLA nonwoven fabric as a grain layer and a manufacturing method therefor, the eco-artificial leather comprising: a plant-derived base layer (10) made of a nonwoven fabric, a woven fabric, or a knitted fabric containing 20-40 wt% of PLA and 60-80 wt% of plant fibers; a grain layer (20) made of a thin PLA nonwoven fabric having a lower basis weight than the plant-derived base layer (10) and laminated on the plant-derived base layer (10); a surface coating layer (30) coated on the grain layer (20) and having a leather pattern formed on the surface thereof by embossing; and a surface protection layer (40) coated on the surface coating layer (30).

Description

Eco-artificial leather having a PLA nonwoven fabric as the silver layer and method for manufacturing the same

[0001] The present invention relates to an eco-artificial leather having a PLA nonwoven fabric as the silver layer and a method for manufacturing the same, and to a new eco-artificial leather that is environmentally friendly and of excellent quality due to its high biomass content including PLA, and a method for easily manufacturing such eco-artificial leather.

[0002] Artificial leather possesses a soft texture and unique appearance similar to natural leather, while offering flexibility and elasticity that cannot be expected from natural leather; therefore, it is being used as a substitute for natural leather in various fields such as shoes, clothing, gloves, miscellaneous goods, furniture, interior materials, and automotive interior materials.

[0003] However, since synthetic polymer raw materials and chemical adhesives are used in the manufacturing of such artificial leather, as well as organic solvents harmful to the human body, problems such as environmental pollution and harm to human health arise during production. Furthermore, environmental pollution caused by the artificial leather discarded after use also occurs.

[0004] To address these issues, biodegradable artificial leather using PLA is being provided. Biodegradable artificial leather is produced by forming a surface coating layer on a base layer made of biodegradable nonwoven fabric, forming a leather pattern on the surface coating layer using an embossing roll or similar method, and then coating a protective layer to protect the surface.

[0005] Meanwhile, because PLA is hard and easily breaks, most biodegradable artificial leathers use a nonwoven fabric mixed with plant fibers such as cotton, jute, pineapple leaves, hemp, bamboo, banana stems, Hanji, and viscose rayon as a base layer to solve this problem. However, while PLA fibers have a uniform thickness and length, the aforementioned plant fibers do not, so the surface of the nonwoven fabric mixed with these plant fibers is not smooth and is uneven. Consequently, it is difficult to form a leather pattern by applying a surface coating of uniform thickness on top of it, and for this reason, a problem arises where the quality of the artificial leather deteriorates.

[0006] The present invention aims to solve the above-mentioned problems, and the objective of the present invention is to provide a new high-quality eco-synthetic leather that is environmentally friendly due to its high biomass content, including PLA, and has excellent surface smoothness, flexibility, and strength, as well as a method for easily manufacturing such eco-synthetic leather.

[0007] According to a feature of the present invention, an eco-artificial leather having a PLA nonwoven fabric as the silver layer is provided, characterized by comprising: a plant-derived base layer (10) made of a nonwoven fabric, woven fabric, or knitted fabric comprising 20 to 40 weight% of PLA and 60 to 80 weight% of plant fibers; a silver layer (20) laminated on the plant-derived base layer (10), which is made of a thin PLA nonwoven fabric with a lower basis weight than the plant-derived base layer (10); a surface coating layer (30) coated on the silver layer (20), having a leather pattern formed on its surface by embossing; and a surface protection layer (40) coated on the surface coating layer (30).

[0008] According to another feature of the present invention, the surface coating layer (30) is formed by coating with a bio-derived polyurethane resin or a natural latex resin, the surface protection layer (40) is formed by coating with either enamel or varnish, the plant fiber is composed of at least one of cotton, jute, viscose rayon fiber, pineapple leaf, hemp, bamboo, banana stem, or Hanji, and the plant-derived base layer (10) has a basis weight of 100 to 1000 g / m² 2 It is made of needle-punched nonwoven fabric, and the silver layer (20) has a basis weight of 15 to 60 g / m² 2 It is made of PLA spunbonded nonwoven fabric.

[0009] According to another feature of the present invention, the plant-derived base layer (10) is impregnated with a bio-derived polyurethane resin or a natural latex resin.

[0010] According to another feature of the present invention, the process comprises: preparing a plant-derived base layer (10) made of a nonwoven fabric, woven fabric, or knitted fabric comprising 20-40% by weight of PLA and 60-80% by weight of plant fibers; preparing a thin silver-faced layer (20) made of a PLA nonwoven fabric and having a lower basis weight than the plant-derived base layer (10); coating a bio-derived polyurethane resin or natural latex resin onto the plant-derived base layer (10) and laminating the silver-faced layer (20) thereon; forming a surface coating layer (30) by coating a bio-derived polyurethane resin or natural latex resin onto the silver-faced layer (20); forming a leather pattern by heat-embossing the upper surface of the surface coating layer (30); and forming a surface protection layer (40) by coating either enamel or varnish onto the surface coating layer (30).

[0011] The present invention, as described above, enables the production of high-quality artificial leather with excellent surface smoothness, flexibility, and strength by laminating a silver surface layer with higher smoothness than the plant-derived base layer onto a plant-derived base layer and forming a leather pattern by forming a surface coating layer thereon. In addition, the present invention has the advantage of being eco-friendly due to the high content of biomaterials, including PLA.

[0012] FIG. 1 is a cross-sectional view of a preferred embodiment of the present invention.

[0013] The present invention will be explained in more detail below.

[0014] As illustrated, the present invention comprises a plant-derived base layer (10), a silver surface layer (20), a surface coating layer (30), and a surface protection layer (40), and each layer is described in detail as follows.

[0015] (1) Plant-derived base layer (10)

[0016] : The plant-derived base layer (10) is made of a needle-punched nonwoven fabric or woven fabric or knitted fabric made of 20-40% by weight of PLA (poly lactic acid) and 60-80% by weight of plant fibers made of cotton, jute, pineapple leaves, hemp, bamboo, banana stems, Hanji, viscose rayon, etc.

[0017] Specifically, the plant-derived base layer (10) is made of a needle-punched nonwoven fabric manufactured by mixing PLA fibers and the plant fibers in the aforementioned ratio, or is made of a fabric or knitted fabric manufactured by PLA-plant fiber blended spun yarn in which PLA and the plant fibers are blended in the aforementioned ratio. The plant fibers are made by finely fiberizing cotton, jute, viscose rayon fibers, or pineapple leaves, hemp, bamboo, banana stems, Hanji, etc.

[0018] If the PLA content of the plant-derived base layer (10) is less than 20% by weight, the tensile strength of the plant-derived base layer (10) is weakened during the heating embossing process for forming a leather pattern described later, and there is a risk that the plant-derived base layer (10) will be damaged. If the PLA content exceeds 40% by weight, the flexibility of the plant-derived base layer (10) is excessively reduced due to the hardness of the PLA, and the quality of the leather is degraded, so it is not desirable.

[0019] Preferably, the plant-derived base layer (10) is made of a needle-punched nonwoven fabric made by mixing one or more of the above plant fibers with PLA fibers having a fineness of 1-15 denier and a length of 20-60 mm, and PLA fibers having an average molecular weight (Mw) of 120,000 g / mol or more. If the PLA fibers are made of PLA with an average molecular weight (Mw) of less than 120,000 g / mol, the durability of the PLA fibers is reduced due to the non-crystallization characteristics of PLA, and a problem arises in which the durability of the plant-derived base layer (10) is excessively reduced.

[0020] In addition, the basis weight of this plant-derived base layer (10) is 100 to 1000 g / m² 2 It is preferable that the basis weight of the plant-derived base layer (10) is 100g / m² 2 In this case, the thickness of the plant-derived base layer (10) is preferably 0.3 mm, and the basis weight of the plant-derived base layer (10) is 1000 g / m² 2 In this case, the thickness of the plant-derived base layer (10) is preferably 3 mm.

[0021] In some cases, a bio-derived polyurethane resin or a natural latex resin may be impregnated into the plant-derived base layer (10) to increase the elongation and elasticity of the plant-derived base layer (10). In particular, using a bio-derived polyurethane resin or a natural latex resin helps to increase the biomass content of the present invention. As is well known, the bio-derived polyurethane resin refers to a polyurethane resin using a bio-derived polyol or a bio-derived isocyanate.

[0022] (2) Silver layer (20)

[0023] : The silver layer (20) is made of PLA spunbond nonwoven fabric or PLA spunlace nonwoven fabric, and unlike the plant-derived base layer (10), the silver layer (20) is made only of PLA fibers, so it has a higher smoothness compared to the plant-derived base layer (10).

[0024] This silver layer (20) has a lower basis weight and a thinner thickness compared to the plant-derived base layer (10), preferably with a basis weight of 15 to 60 g / m² 2 It is made of spunbonded nonwoven fabric.

[0025] The basis weight of the silver layer (20) is 15 g / m² 2 If it is less than that, the thickness of the silver layer (20) is excessively thin, so the function of the silver layer (20) to increase the smoothness of the plant-derived base layer (10) is not properly performed, and the basis weight of the silver layer (20) is 60 g / m² 2 If it exceeds the limit, the flexibility of the silver layer (20) is excessively reduced due to the hard and brittle characteristics of PLA, resulting in a decrease in the quality of the leather.

[0026] A bio-derived polyurethane resin or natural latex resin is coated onto the above plant-derived base layer (10) to a thickness of 5 to 20 μm, and a silver layer (20) is pressed onto it to be laminated with the plant-derived base layer (10). When the silver layer (20) is laminated onto the plant-derived base layer (10) using a bio-derived polyurethane resin or natural latex resin, the biomass content of the present invention is improved compared to the case where other types of binders or adhesives are used.

[0027] (3) Surface coating layer (30)

[0028] : The surface coating layer (30) is formed by coating a bio-derived polyurethane resin or natural latex resin to a thickness of 10 to 40 μm on a silver surface layer (20) laminated to the plant-derived base layer (10) and forming a leather pattern.

[0029] Natural dyes or pigments may be added to the surface coating layer (30) to impart various colors, or a color layer may be printed separately on the surface coating layer (30) to impart color. The thickness of the surface coating layer (30) is appropriately adjusted at the above thickness level according to the product and application to which it is applied.

[0030] More specifically, a bio-derived polyurethane resin or natural latex resin is coated onto the silver surface layer (20) and dried, and then a leather pattern is formed on the surface coating layer (30) by pressing with a heating embossing roll.

[0031] (4) Surface protection layer (40)

[0032] : The surface protection layer (40) is for preventing scratches and is formed by coating a paint such as enamel or varnish on the surface coating layer (30).

[0033] Experimental Example 1

[0034] Leather with the composition shown in Table 1 was made.

[0035] Base layer PLA staple fiber 40 wt% + vegetable fiber 60 wt%, basis weight 300 g / m² 2 , 1mm thick needle-punched nonwoven silver-faced PLA spunbonded nonwoven fabric, basis weight 15g / m² 2 , laminated surface coating layer with natural latex resin to a thickness of 20㎛ on the base layer, then surface coated with natural latex resin to a thickness of 15㎛, then formed a leather pattern using a heat-pressing roller, and finally applied an enamel coating to the painted surface protection layer.

[0036] Leather with the same composition as Table 2 in Experimental Example 2 was made.

[0037] Base layer PLA staple fiber 40 wt% + vegetable fiber 60 wt%, basis weight 300 g / m² 2 , 1mm thick needle-punched nonwoven silver-faced PLA spunbonded nonwoven fabric, basis weight 60g / m² 2, laminated surface coating layer with natural latex resin to a thickness of 20㎛ on the base layer, then surface coated with natural latex resin to a thickness of 15㎛, then formed a leather pattern using a heat-pressing roller, and finally applied an enamel coating to the painted surface protection layer.

[0038] Comparative Example 1: Leather with the same composition as Table 3 was made.

[0039] Base layer PLA staple fiber 40 wt% + vegetable fiber 60 wt%, basis weight 300 g / m² 2 , after surface coating a 1mm thick needle-punched nonwoven fabric surface coating layer with natural latex resin to a thickness of 20㎛, forming a leather pattern using a heat-pressing roller, and then applying an enamel coating to the painted surface protection layer.

[0040] Comparative Example 2 made leather with the same composition as Table 4.

[0041] Base layer PLA staple fiber 20 wt% + vegetable fiber 80 wt%, basis weight 300 g / m² 2 , after surface coating a 1mm thick needle-punched nonwoven fabric surface coating layer with natural latex resin to a thickness of 20㎛, forming a leather pattern using a heat-pressing roller, and then applying an enamel coating to the painted surface protection layer.

[0042] <Surface Sensory Test> The surfaces of Examples 1 and 2 and Comparative Examples 1 and 2 were visually inspected, and the results are as shown in Table 5.

[0043] Surface Smoothness Surface Wrinkle Flexibility Experiment Example 1 Medium Medium Upper Experiment Example 2 Upper High Medium Comparative Example 1 Lower Lower Lower Comparative Example 2 Lower Lower Medium

[0044] As can be seen from Table 5, Examples 1 and 2 had better surface properties compared to the Comparative Examples, and Example 2, in particular, received the best evaluation in all categories.

[0045] Physical property test

[0046] The tensile strength and tear strength of Experimental Examples 1 and 2 and Comparative Examples 1 and 2 were measured, and the average of five measurements was calculated. The results are shown in Table 6.

[0047] * Test method

[0048] - Tensile strength: Grab method (compliant with KS K 0520 : 2021)

[0049] - Tear strength: Single tear method (compliant with KS K 0536:2019)

[0050] Tensile Strength (N) Tear Strength (N) Lengthwise Widthwise Lengthwise Widthwise Experimental Example 167063070.558.7 Experimental Example 287184292.486.2 Comparative Example 152149872.460.1 Comparative Example 251148169.358.7

[0051] As can be seen from Table 6, Experimental Examples 1 and 2 have superior tensile strength compared to the Comparative Examples, and in particular, Experimental Example 2 had superior tensile strength and tear strength compared to the Comparative Examples.

Claims

1. A plant-derived base layer (10) made of a nonwoven fabric, woven fabric, or knitted fabric comprising 20~40% by weight of PLA and 60~80% by weight of plant fibers; A silver surface layer (20) laminated on the plant-derived base layer (10), which is made of a thin PLA nonwoven fabric with a lower basis weight compared to the plant-derived base layer (10); A surface coating layer (30) coated on the silver surface layer (20), having a leather pattern formed on its surface by embossing; and It includes a surface protection layer (40) coated on the surface coating layer (30) above, and The above surface coating layer (30) is formed by coating with a bio-derived polyurethane resin or a natural latex resin, and The above surface protection layer (40) is formed by coating with either enamel or varnish, and Eco-artificial leather characterized in that the above-mentioned plant fiber is composed of at least one of cotton, jute, viscose rayon fiber, pineapple leaf, hemp, bamboo, banana stem, or Hanji.

2. In Paragraph 1, The above plant-derived base layer (10) has a basis weight of 100 to 1000 g / m² 2 It is made of needle-punched nonwoven fabric, and The above silver layer (20) has a basis weight of 15 to 60 g / m² 2 Eco-synthetic leather having a silver layer of a PLA nonwoven fabric characterized by being made of a PLA spunbonded nonwoven fabric.

3. A process of preparing a plant-derived base layer (10) made of a nonwoven fabric, woven fabric, or knitted fabric comprising 20~40% by weight of PLA and 60~80% by weight of plant fibers; A process of preparing a thin silver layer (20) made of PLA nonwoven fabric, having a lower basis weight compared to the plant-derived base layer (10); A process of coating a bio-derived polyurethane resin or natural latex resin onto the above plant-derived base layer (10) and laminating the above silver surface layer (20) thereon; A process of forming a surface coating layer (30) by coating a bio-derived polyurethane resin or natural latex resin on the silver surface layer (20); A process of forming a leather pattern by heat embossing the upper surface of the above surface coating layer (30); and A method for manufacturing eco-artificial leather using a PLA nonwoven fabric as the silver layer, characterized by including the process of forming a surface protection layer (40) by coating one of enamel or varnish on the surface coating layer (30).

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