KR102795938B1 - Eco artificial leather with PLA nonwoven and manufacturing method of the same that - Google Patents

Abstract

The present invention relates to a new, high-quality eco-artificial leather having a high biomass content including PLA, being environmentally friendly, and having excellent surface smoothness, flexibility, and strength, and a method for easily manufacturing such eco-artificial leather.
According to the present invention, an eco-artificial leather using a PLA nonwoven fabric as a silver layer and a method for manufacturing the same are provided, characterized in that the eco-artificial leather includes a plant-derived base layer (10) made of a nonwoven fabric, woven fabric or knitted fabric containing 20 to 40 wt% of PLA and 60 to 80 wt% of plant-derived fiber; a silver layer (20) made of a PLA nonwoven fabric having a lower basis weight and thinner than that of the plant-derived base layer (10) and laminated on the plant-derived base layer (10); a surface coating layer (30) coated on the silver layer (20) and having a leather pattern formed on the surface by embossing; and a surface protection layer (40) coated on the surface coating layer (30).

Description

Eco-artificial leather with PLA nonwoven as silver layer and manufacturing method thereof {Eco artificial leather with PLA nonwoven and manufacturing method of the same that}

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

Artificial leather has a soft texture and unique appearance similar to natural leather, but can also provide flexibility and elasticity that cannot be expected from natural leather, so it is used as a substitute for natural leather in various fields such as shoes, clothing, gloves, miscellaneous goods, furniture, interior decoration materials, and automobile interior materials.

However, when manufacturing artificial leather, synthetic polymer raw materials and chemical adhesives are used, and organic solvents that are harmful to the human body are also used, so environmental problems and human harmfulness problems arise when manufacturing artificial leather. In addition, environmental pollution problems arise due to artificial leather discarded after use.

For these problems, biodegradable artificial leather using PLA is provided. This biodegradable artificial leather is made by forming a surface coating layer on a base layer made of biodegradable non-woven fabric, forming a leather pattern on this surface coating layer using an embossing roll, etc., and then coating a protective layer to protect the surface.

However, since PLA is hard and breaks easily, to solve this problem, most biodegradable artificial leathers use a non-woven fabric as a base layer in which vegetable fibers such as cotton, jute, pineapple leaves, hemp, bamboo, banana stems, Korean paper, and viscose rayon are mixed with PLA fibers. However, while PLA fibers have a constant thickness and length, the vegetable fibers do not have constant thickness and length, so the non-woven fabric mixed with these vegetable fibers has an uneven surface rather than a smooth surface. Therefore, it is not easy to form a leather pattern by applying a surface coating with a uniform thickness on top, and for this reason, the quality of the artificial leather is poor.

Republic of Korea Publication Patent No. 10-2023-0139495 (October 5, 2023) Republic of Korea Patent No. 10-2010-0096637 (May 22, 2023)

The present invention is intended to solve the above problems, and an object of the present invention is to provide a new, high-quality eco-artificial leather having a high biomass content including PLA, which is environmentally friendly, and has excellent surface smoothness, flexibility, and strength, and a method for easily manufacturing such eco-artificial leather.

According to a feature of the present invention, an eco-artificial leather using a PLA nonwoven fabric as a silver layer is provided, characterized in that it comprises a plant-derived base layer (10) made of a nonwoven fabric, woven fabric or knitted fabric containing 20 to 40 wt% of PLA and 60 to 80 wt% of plant-derived fiber; a silver layer (20) made of a PLA nonwoven fabric having a lower basis weight and thinner than that of the plant-derived base layer (10) and laminated on the plant-derived base layer (10); a surface coating layer (30) coated on the silver layer (20) and having a leather pattern formed on the surface by embossing; and a surface protection layer (40) coated on the surface coating layer (30).

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

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

According to another feature of the present invention, the present invention comprises: a process for preparing a plant-derived base layer (10) made of a nonwoven fabric, woven fabric or knitted fabric containing 20 to 40 wt% of PLA and 60 to 80 wt% of plant-derived fiber; a process for preparing a silver layer (20) made of a PLA nonwoven fabric and having a lower basis weight and thinner thickness than the plant-derived base layer (10); a process for coating a bio-derived polyurethane resin or natural latex resin on the plant-derived base layer (10) and laminating the silver layer (20) thereon; a process for forming a surface coating layer (30) by coating a bio-derived polyurethane resin or natural latex resin on the silver layer (20); a process for forming a leather pattern by heat embossing the upper surface of the surface coating layer (30); and a process for forming a surface protection layer (40) by coating one of enamel and varnish on the surface coating layer (30).

The present invention, as described above, can produce high-quality artificial leather having excellent surface smoothness, flexibility, and strength by laminating a silver layer having a higher smoothness than the plant-derived base layer on a plant-derived base layer and forming a surface coating layer thereon to form a leather pattern. In addition, the present invention has an environmentally friendly advantage because it has a high content of biomaterials including PLA.

Figure 1 is a cross-sectional view of a preferred embodiment of the present invention.

The present invention is described in more detail below.

As illustrated, the present invention comprises a plant-derived base layer (10), a silver layer (20), a surface coating layer (30), and a surface protection layer (40). Each layer will be described in detail as follows.

(1) Plant-derived base layer (10)

: The plant-derived base layer (10) is made of needle-punched non-woven fabric or fabric, knitted fabric, etc., made of 20 to 40 wt% PLA (polylactic acid) and 60 to 80 wt% vegetable fibers such as cotton, jute, pineapple leaves, hemp, bamboo, banana stems, Korean paper, viscose rayon, etc.

Specifically, the plant-derived base layer (10) is made of a needle-punched nonwoven fabric manufactured by mixing PLA fibers and the plant-derived fibers in the ratio mentioned above, or a fabric or knitted fabric manufactured from a PLA-plant-derived fiber blended yarn in which PLA and the plant-derived fibers are mixed in the ratio mentioned above. The plant-derived fibers are cotton, jute, viscose rayon fibers, or pineapple leaves, hemp, bamboo, banana stems, Korean paper, etc. that have been finely fiberized.

If the PLA content of the plant-derived base layer (10) is less than 20 wt%, there is a risk that the tensile strength of the plant-derived base layer (10) will be weakened and the plant-derived base layer (10) will be damaged during the heat embossing process for forming a leather pattern described later, and if the PLA content exceeds 40 wt%, the flexibility of the plant-derived base layer (10) will be excessively reduced due to the hardness of PLA, which is not desirable because the quality of the leather will deteriorate.

Preferably, the plant-derived base layer (10) is made of a needle-punched nonwoven fabric made by mixing PLA fibers having a diameter of 1-15 denier and a length of 20-60 mm with at least one of the plant-derived fibers using PLA having an average molecular weight (Mw) of 120,000 g/mol or more. When the average molecular weight (Mw) of PLA is less than 120,000 g/mol, the durability of PLA is reduced due to the non-crystallization characteristic of PLA, which causes a problem in that the durability of the plant-derived base layer (10) is excessively reduced.

In addition, the basis weight of the plant-derived base layer (10) is preferably 100 to 1000 g/m ² , and when the basis weight is 100 g/m ² , the thickness is preferably 0.3 mm, and when the basis weight is 1000 g/m ² , the thickness is preferably 3 mm.

In some cases, the plant-derived base layer (10) may be impregnated with a bio-derived polyurethane resin or a natural latex resin to increase the elongation and elasticity of the plant-derived base layer (10). In particular, the use of 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 is a polyurethane resin synthesized using a polyol manufactured from animal or vegetable fats without using a synthetic polyol.

(2) Silver layer (20)

: The silver layer (20) is made of PLA spunbonding nonwoven fabric or PLA spunlace nonwoven fabric. Unlike the plant-derived base layer (10), the silver layer is made only of PLA fibers, so it has a higher smoothness than the plant-derived base layer (10).

This silver layer (20) is made thinner and has a lower basis weight than the plant-derived base layer (10), and is preferably made of a spunbonding nonwoven fabric having a basis weight of 15 to 60 g/m ² .

If the weight of the silver layer (20) is less than 15 g/m ² , the thickness of the silver layer (20) is excessively thin, and the function of the silver layer (20) to increase the smoothness of the plant-derived base layer (10) is not properly performed. If the weight of the silver layer (20) exceeds 60 g/m ² , the flexibility of the silver layer (20) is excessively reduced due to the hard and brittle characteristics of PLA, and the quality of the leather deteriorates.

This silver layer (20) is laminated to the plant-derived base layer (10) by coating a bio-derived polyurethane resin or natural latex resin with a thickness of 5 to 20 ㎛ on the plant-derived base layer (10) and pressing the silver layer (20) thereon. When the silver layer (20) is laminated to the plant-derived base layer (10) using the bio-derived polyurethane resin or natural latex resin, the biomass content of the present invention can be increased. The bio-derived polyurethane resin refers to a polyurethane resin using bio-derived polyol or bio-derived isocyanate.

(3) Surface coating layer (30)

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

Natural dyes or pigments can be added to the surface coating layer (30) to impart various colors, and a color layer can also 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 depending on the product and purpose to which it is applied.

More specifically, a bio-derived polyurethane resin or natural latex resin is coated on the silver layer (20), dried, and then pressed with a heating embossing roll to form a leather pattern on the surface coating layer (30).

(4) Surface protection layer (40)

: The surface protection layer (40) is for scratch prevention and is formed by coating a paint such as enamel or varnish on the surface coating layer (30).

Experimental Example 1

Leather with the same composition as Table 1 was made.

Base layer Needle-punched nonwoven fabric with 40 wt% PLA staple fiber + 60 wt% vegetable fiber, weight 300 g/ ^m2 , thickness 1 mm Silver layer PLA span bonding non-woven fabric, 15 g/ ^m2 in basis weight, 15 ㎛ thick, laminated to the base layer with natural latex resin Surface coating layer After applying a surface coating of 20㎛ thick natural latex resin, a leather pattern is formed using a heat press roll and then painted. Surface protection layer Enamel coating

Experimental example 2

Leather with the same composition as Table 2 was made.

Base layer Needle-punched nonwoven fabric with 40 wt% PLA staple fiber + 60 wt% vegetable fiber, weight 300 g/ ^m2 , thickness 1 mm Silver layer PLA span bonding non-woven fabric, 60 g/ ^m2 in basis weight, 15 ㎛ thick, laminated to the base layer by natural latex resin Surface coating layer After applying a surface coating of 20㎛ thick natural latex resin, a leather pattern is formed using a heat press roll and then painted. Surface protection layer Enamel coating

Comparative Example 1

Leather with the same composition as Table 3 was made.

Base layer Needle-punched nonwoven fabric with 40 wt% PLA staple fiber + 60 wt% vegetable fiber, weight 300 g/ ^m2 , thickness 1 mm Surface coating layer After applying a surface coating of 20㎛ thick natural latex resin, a leather pattern is formed using a heat press roll and then painted. Surface protection layer Enamel coating

Comparative Example 2

Leather with the same composition as Table 4 was made.

Base layer Needle-punched non-woven fabric with 20 wt% PLA staple fiber + 80 wt% vegetable fiber, weight 300 g/ ^m2 , thickness 1 mm Surface coating layer After applying a surface coating of 20㎛ thick natural latex resin, a leather pattern is formed using a heat press roll and then painted. Surface protection layer Enamel coating

<Surface sensory test>

The surfaces of Examples 1 and 2 and Comparative Examples 1 and 2 were visually inspected, and the results are shown in Table 5.

Surface smoothness Surface wrinkles pliability Experimental Example 1 middle middle award Experimental example 2 award award middle Comparative Example 1 under under under Comparative Example 2 under under middle

As can be seen in Table 5, Examples 1 and 2 had better surface properties than the comparative examples, and in particular, Example 2 received the best evaluation in all items.

<Property Test>

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

* Test method

- Tensile strength: Grab method (KS K 0520: 2021 applied)

- Tear strength: Single tear method (KS K 0536:2019 applied)

Tensile strength (N) Tear strength (N) Lengthwise Width direction Lengthwise Width direction Experimental Example 1 670 630 70.5 58.7 Experimental example 2 871 842 92.4 86.2 Comparative Example 1 521 498 72.4 60.1 Comparative Example 2 511 481 69.3 58.7

As can be seen in Table 6, Experimental Examples 1 and 2 have superior tensile strength compared to the comparative examples, and in particular, Experimental Example 2 has superior tensile strength and tear strength compared to the comparative examples.

Claims (4)

A plant-derived base layer (10) made of a nonwoven fabric, fabric or knitted fabric containing 20 to 40 wt% of PLA and 60 to 80 wt% of plant-derived fiber;
A silver layer (20) made of PLA nonwoven fabric having a lower basis weight and thinner than the plant-derived base layer (10) and laminated on the plant-derived base layer (10);
A surface coating layer (30) coated on the silver layer (20) and having a leather pattern formed on the surface by embossing; and
It includes a surface protection layer (40) coated on the surface coating layer (30);
The above surface coating layer (30) is formed by coating bio-derived polyurethane resin or natural latex resin,
The above surface protection layer (40) is formed by coating one of enamel and varnish,
The above vegetable fiber is made of at least one of cotton, jute, viscose rayon fiber, pineapple leaves, hemp, bamboo, banana stem, and Korean paper.
The above plant-derived base layer (10) is made of needle-punched nonwoven fabric having a basis weight of 100 to 1000 g/ ^m2 .
Eco-artificial leather using PLA nonwoven fabric as the silver layer, characterized in that the silver layer (20) is made of PLA spunbonded nonwoven fabric having a basis weight of 15 to 60 g/m ^{2 .}
A process for preparing a plant-derived base layer (10) made of a nonwoven fabric, fabric or knitted fabric containing 20 to 40 wt% of PLA and 60 to 80 wt% of plant-derived fiber;
A process for preparing a silver layer (20) made of PLA non-woven fabric and having a lower weight and thinner surface than the plant-derived base layer (10);
A process of coating the plant-derived base layer (10) with bio-derived polyurethane resin or natural latex resin and laminating the silver 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 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 PLA nonwoven fabric as a silver layer, characterized by including a process of forming a surface protection layer (40) by coating one of enamel and varnish on the surface coating layer (30). delete delete

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