KR101976120B1 - Manufacturing method of artificial leather - Google Patents

Abstract

The present invention The present invention relates to a method of manufacturing artificial leather, wherein the non-woven fabric made of island-in-the-sea fibers is shrunk, the sea component is pre-dissolved, and the high-speed fluid treatment is used to increase the fiber on the surface of the artificial leather by impregnating the polymer elastomer on the back side after densification. Due to the difference in the density and the content of the polymer elasticity of the surface and the back, it is possible to provide an artificial leather that is excellent in mechanical properties, but the surface feel is improved and given a luxurious appearance.

Description

Manufacturing method of artificial leather

The present invention The present invention relates to a method of manufacturing artificial leather, and more particularly, to a method of manufacturing artificial leather, which has a soft texture, a high-quality appearance, and excellent fastness due to an increased fiber density and a reduced polymer elastic body on the surface, unlike conventional artificial leather. It is about.

Conventional manufacturing method of artificial leather using a nonwoven fabric is generally formed by forming a nonwoven fabric through a nonwoven fabric manufacturing process such as needle punching using island-in-the-sea microfiber, imparting a polymer elastic body, and then eluting the sea component using an appropriate solvent. After miniaturization, surface brush is formed, and artificial leather is manufactured by dyeing and post-processing the desired color.

When using this manufacturing technique, the nonwoven fabric made of island-in-the-sea yarns is first fixed by the polymer elastic body, thereby limiting the improvement of the density of the island components, thereby limiting the formation of a luxurious appearance and a soft feel.

Therefore, in order to improve the density of the nonwoven fabric, a method of increasing the nonwoven fabric density by using heat shrinkage under hot water and steam after manufacturing the nonwoven fabric has been utilized. However, this method also includes sea components, so that there is a limit in maximizing the neighboring density of the island components. have.

In order to solve this limitation, the method of increasing the density between islands is being applied by first dissolving the sea component before the polymer elastic body is imparted, but in this case, the nonwoven fabric after elution has extremely low morphological stability, which leads to easy deformation. In order to prevent this, pretreatment of the foam is necessary. In addition, since a direct adhesive structure is formed between the polymer elastomer and the island component, the mechanical properties are increased, but there is a problem that may inhibit the flexibility, the soft feel, and the luxurious appearance in the emotional part.

Republic of Korea Patent Publication No. 0475542 (Invention name: Manufacturing method of ultra-fine non-woven artificial leather)

The present invention, in order to solve the above problems, in the manufacturing process of artificial leather by adjusting the density of the non-woven fabric and improving the process of imparting a polymer elastomer, while having a shape stability and excellent touch, luxury appearance and excellent fastness The purpose is to provide.

In order to solve the above problems, the present invention, in the manufacturing method of artificial leather, comprising the steps of producing a sea island (sea island) fiber through a composite spinning process; Manufacturing a nonwoven fabric using the island-in-the-sea fibers; Shrinking the nonwoven fabric; Eluting the sea component of the contracted nonwoven fabric; Manufacturing a high density nonwoven fabric by treating the nonwoven fabric from which the sea component is eluted with a high speed fluid; Hydroprocessing the high density nonwoven fabric; It provides a method of manufacturing artificial leather, including the step of coating a polymer elastic body on the back surface of the water-treated high-density nonwoven fabric and forming a brush on the surface of the nonwoven fabric in the coating step.

According to the present invention, due to the difference in the density of fibers increased in the surface of the artificial leather and the content of the elastic material on the surface and the back, the mechanical properties can be improved, but the feel of the surface is improved, and the artificial leather has a high-quality appearance and excellent fastness. Can be.

1 is a cross-sectional photograph of artificial leather treated with an elastic body after pre-dissolution according to an embodiment of the present invention,
2 is a cross-sectional photograph of an artificial leather prepared by impregnating an elastomer after post-dissolution,
3 is a high speed fluid processing process diagram in accordance with an embodiment of the present invention.

Hereinafter, the manufacturing method of the artificial leather of the present invention will be described in detail.

In the method of manufacturing artificial leather of the present invention, the island-in-the-sea fiber is manufactured through a composite spinning process, a nonwoven fabric is manufactured using the island-in-the-sea fiber and the nonwoven fabric is shrunk to increase the density, and Pre-elute the increased sea component of the nonwoven fabric, and increase the density of the nonwoven fabric from which the sea component is eluted again using a spunlace method to produce a high-density nonwoven fabric, and to hydrolyze the high-density nonwoven fabric and to coat a polymer elastomer on the back surface thereof. It can be prepared including the step.

The process for producing the island-in-the-sea fibers comprises a composite spinning process using a first polymer of sea component dissolved and eluted in a solvent and a second polymer of island component remaining without being dissolved in a solvent. Include.

The first polymer of the sea component may be made of copolyester, polystyrene or polyethylene, and preferably made of copolyester having excellent solubility in an alkaline solvent.

As the second polymer of the island component, it may be made of nylon or polyester which is not dissolved in an alkaline solvent and can be dyed with a disperse dye, and specifically, polyethylene terephthalate, polyoxyethylene benzoate, and polybutylene tere. Phthalate, polytrimethylene terephthalate, polyamide, polyacryl, polyvinyl alcohol, polytriethylene terephthalate, acetate, etc. are mentioned.

The island-in-the-sea fibers have a fineness of 0.3 denier or less after the first polymer which is a sea component is eluted, and enhances the feel of microfine fibers, and is preferably 0.001 denier or more for dyeing fastness and strength.

The manufacturing process of the nonwoven fabric includes a process of laminating a plurality of webs through a carding process and a crosslapping process of the island-in-the-sea fibers in a staple state and through the needles of the formed webs. It includes a needle punching process that needle punches to a density of 2000 to 2400 ppsc.

In the present invention, the method for shrinking the nonwoven fabric can be carried out by passing the nonwoven fabric through steam or hot water. When steam is used, the nonwoven fabric can be carried out at a temperature of 80 to 110 ° C. and a relative humidity of 90% or more, and when hot water is used, 80 ° C. It can be performed by holding for 1 minute or more in the above boiling water.

The shrinkage can improve the density of the nonwoven fabric, thereby increasing the density more easily during the next step of high-speed fluid treatment, thereby increasing the surface density of the surface in artificial leather, the final product, thereby increasing polymers such as polyurethane. It is possible to improve the surface appearance quality by preventing a decrease in the fastness due to the elastic body, and improve the quality of the emotion by improving the volume and the touch.

In this case, the density of the nonwoven fabric is preferably 0.400 to 0.450 g / cm 3 by the shrinkage, so that the final density can be increased while facilitating pre-dissolution, the density can be adjusted according to the variety.

In the present invention, it is possible to form an ultrafine fiber by eluting and removing the sea component using an aqueous alkali solution such as caustic soda.

In the present invention, the method of restoring the density decrease due to the voids generated by the dissolution of the sea component and increasing again uses a high-speed fluid treatment method, imparting a high pressure water flow pressure on the surface of the nonwoven fabric from which the sea component is eluted, By absorbing and carrying out, the nonwoven fabric from which the sea component is eluted can be shrunk to increase the density again to form a high density nonwoven fabric.

By increasing the density of non-woven fabrics from which sea component is eluted by high-speed fluid treatment, the surface density of the surface increases in artificial leather, which is the final product, thereby preventing a decrease in the fastness by high-molecular elastomers such as polyurethane. Appearance quality can be improved, and the emotional quality can be improved by improving the volume and touch.

In the case of post-eluting, which is a conventional method, it proceeds after processing the elastic body. When the elastic body is impregnated, the elastic body is contained in the portion except for the yarn, so that the island component and the elastic body remain in shape after dissolution. There is a limit to increase the density of the product.

On the other hand, according to the present invention, before the high-speed fluid treatment of the nonwoven fabric and before the elastic body treatment, the preliminary elution of the sea component constituting the yarn and the sea component of the island component is performed to elute a single strand of yarn to remove the sea component. It forms the island and removes the space occupied by the sea component first, and then improves the distribution and density of the island component in the space from which the sea component is removed by high-speed fluid treatment to form a shape similar to that of natural leather. Can be expressed.

After the elastic body is processed, the separation and density is already determined, the elastic body enters the voids between the fibers can be obtained in the final product with improved density.

In the method of hydroprocessing the high density nonwoven fabric, the high density nonwoven fabric is immersed in 15 to 20% by weight of dimethylformamide (DMF) aqueous solution, and passed through a pressing roll to primarily increase the water content of the nonwoven fabric to 50 to 70% by weight. After adjusting, it can be carried out by adjusting the secondary so that the water content is 10 to 30% by weight in the high-density nonwoven fabric through a calendar of 100 ~ 120 ℃.

The moisture content can be infiltrated into the high-density nonwoven fabric at a constant rate. If the moisture content is less than 10% by weight, the penetration rate and penetration range in the thickness direction of the nonwoven fabric of the elastic body is too large in the elastic coating step described later, artificial leather It is hard to show soft touch and luxurious appearance because the content of elastic body is increased at the surface side of, and the content of elastic body is present on the surface after the buffing process, and the fastness by the elastic body decreases when measuring the fastness. It is undesirable because the film is formed on the surface of the nonwoven fabric by moisture before permeation into the nonwoven fabric, which is difficult to penetrate any more, and thus the elastic body is unevenly impregnated in the nonwoven fabric, which may lower flexibility, volume and mechanical strength in artificial leather.

In the present invention, the method of coating the polymer elastomer on the back side may be performed to coat the polymer elastic body on the back surface of the water-treated high density nonwoven fabric and penetrate 30 to 70% by depth in the thickness direction of the nonwoven fabric.

As the coating method, knife coating, roll coating, gravure coating, slot die coating, or the like can be used.

If the penetration is less than 30% by depth, the impregnated amount of the polymer elastomer is reduced, and the elasticity, mechanical strength, and shape stability are lowered. If the penetration is more than 70%, the soft leather and the high-quality appearance on the surface of the artificial leather are difficult to exhibit. May be lowered, which is undesirable.

Thereafter, the surface is buffed using sandpaper to form a brush, and after artificial dyeing, artificial leather may be manufactured.

The artificial leather manufactured in this way has a high density of hair on the surface and a low content of polymer elastomer, so there is less direct bonding structure between the polymer elastomer and the fiber, so it is easy to brush and expresses a soft and soft touch, and the appearance quality is excellent. It is possible to remarkably solve various problems of reduced fastness caused by the residual dye present in the polymer elastomer.

In addition, the back portion where the polymer elastomer is widely distributed has elastic properties, and a gradient of the polymer elastomer is formed in the entire artificial leather to express a soft feel.

Hereinafter, the present invention will be described in more detail based on the following Examples and Comparative Examples.

However, the following examples are only for illustrating the present invention, and the present invention is not limited to the following examples, and may be changed to other embodiments equivalent to substitutions and equivalents without departing from the technical spirit of the present invention. It will be apparent to those skilled in the art to which the present invention pertains.

Example 1

The polyester is used as the island component and the copolymerized polyester is the sea component, and the island component: the sea component is composite spun to have a weight ratio of 70:30, and the resulting islands-in-sea filaments are drawn at a draw ratio of 3.0 times and the number of crimps is 13 / inch. The crimp process was carried out as much as possible, followed by heat setting at 130 ° C., and then cut into 51 mm to prepare islands-in-sea short fibers.

The island-in-the-sea short fibers were formed through a carding process and a cross lapping process, and then needle punched to prepare a nonwoven fabric having a weight per unit area of 800 g and an apparent density of 0.2550 g / cm 3.

The nonwoven fabric thus prepared is shrunk by treating it for 5 minutes while passing it at a rate of 1 m / min in hot water at 85 ° C., and then compressing it with a calender to remove moisture. The water content is 50% or less than the weight of the nonwoven fabric and 10 at 120 ° C. Hot air drying was performed for a minute to obtain a shrunken nonwoven fabric. At this time, the obtained nonwoven fabric had a density of 0.412 g / cm 3.

Sea components of the contracted nonwoven fabric were eluted by immersing in an aqueous solution of caustic soda at a concentration of 7.5% by weight.

With respect to the nonwoven fabric from which the sea component is eluted, it is sprayed on the surface with high pressure water of 10 Mpa, 2 times 15 Mpa, 3 to 5 times 25 Mpa, 6 times 20 Mpa as a water flow pressure at an interval of 1 mm nozzle with a diameter of 0.12 mm. The mixture was subjected to hot air drying at 120 ° C. for 10 minutes to obtain a high density nonwoven fabric.

The high-density nonwoven fabric was immersed in 20 wt% DMF aqueous solution, passed through a pressing roll to first adjust the moisture content to 60% of the nonwoven weight, and dried through a calendar at 110 ° C. to adjust the final moisture content to 15 wt% Treated nonwovens were obtained.

On the back side of the water-treated nonwoven fabric, a polyurethane polymer elastomer having a viscosity of 5,000 cps diluted by 10 wt% of DFM was coated with a knife coating method, and an elastomer-impregnated nonwoven fabric in which the elastomer penetrated 60% by depth to the thickness of the nonwoven fabric was prepared. .

Subsequently, the surface of the surface was formed by buffing the surface using sandpaper # 150, # 300, and then brushed on the surface, dyed in a high pressure rapid dyeing machine using a disperse dye, washed, dried, and then treated with a softening agent and an antistatic agent. Leather was manufactured.

Example 2

When manufacturing a high density nonwoven fabric in Example 1 The water flow pressure Artificial leather was manufactured in the same manner as in Example 1, except that pressure 12 Mpa, twice 18 Mpa, three to five times 28 Mpa, and six times 23 Mpa were used.

Example 3

Artificial leather was manufactured in the same manner as in Example 1, except that the moisture content was 25% by weight when the water treatment was performed in Example 1.

Comparative Example 1

Except not shrinking the nonwoven fabric in Example 1, artificial leather was manufactured using the same method as in Example 1.

Comparative Example 2

Except not manufacturing a high-density nonwoven fabric in Example 1, artificial leather was manufactured using the same method as in Example 1.

Comparative Example 3

Except not having a water treatment in Example 1, artificial leather was manufactured using the same method as in Example 1.

[Comparative Example 4]

Artificial leather was manufactured in the same manner as in Example 1, except that the moisture content was 35% by weight when the water treatment was performed in Example 1.

Physical properties of the artificial leather prepared in Examples and Comparative Examples were measured by the following evaluation method, and the results are shown in Table 1.

<Evaluation Method>

1. Apparent Density

Each unit weight of artificial leather is measured by the method of JIS L 1096 8.4.2 (1999), and the thickness is measured with a dial thickness gauge (Ozaki Seisakusho Co., Ltd., product name Pecok H), respectively.

Subsequently, each artificial leather is immersed in a dimethylformaldehyde (DMF) solution at a temperature of 60 ° C. for 24 hours to extract all the polyurethane components inside the artificial leather, followed by washing with water and drying to determine the weight of the nonwoven fabric by the unit weight measurement method and Measure the same.

The apparent density of each layer is calculated | required by calculation from the thickness measurement measured previously and the unit weight value of only the nonwoven fabric after polyurethane extraction.

2. Tensile strength and elongation at break

After cutting 5 pieces of artificial leather fabrics in the horizontal and vertical directions, measure the tensile strength and elongation at break according to ASTM D 5035 standard by using tensile tester and take the average value.

3. Tear strength

After cutting 5 pieces of artificial leather fabrics in the horizontal and vertical directions, measure the tear strength according to ASTM D 2261 standard by using tensile tester and take the average value.

4. Static load elongation (%) and residual reduction rate (%)

After the artificial leather manufacturing process is completed, three pieces of 50 mm wide and 250 mm long dyed paper are taken in the longitudinal and transverse directions, respectively, and a mark of 100 mm in the center is drawn. This is 150 mm clamped, mounted on a Maltensi fatigue tester and slowly loaded with 78.4 N (8 kgf) load (including the lower clamp).

Leave for 10 minutes under load and find the distance between the markings. Next, remove the specimen from the clamp, remove the load, and leave it on a flat surface for 10 minutes to determine the distance between marks.

Static load elongation and residual reduction rate are calculated by the following equation.

Static load elongation (%) = ℓ1-100

Residual Strain Rate (%) = ℓ2 100

Where ℓ1: Distance between marks after 10 minutes of loading (mm)

ℓ2: Distance between marks after 10 minutes without load (mm)

5. Appearance of artificial leather

An evaluation group composed of five experts evaluated sensory evaluation on six points of hair and color uniformity, elasticity, smoothness, smoothness and abundance on a five-point scale, and the results are shown in Table 2.

division density
(g / cm 3) The tensile strength
(kg / cm) Elongation at Break
(%) Tear strength
(kg) Static load elongation
(%) Residual shrinkage
(%) Length width Length width Length width Length width Length width Example 1 0.420 10 7 65 113 5.3 6.6 19 33 11 22 Example 2 0.437 11 9 68 116 5.8 6.3 15 25 8 16 Example 3 0.404 6.3 6.9 52 55 2.8 3.1 19 23 3 6 Comparative Example 1 0.256 6.3 6.6 53 59 2.3 2.1 13 22 5 7 Comparative Example 2 0.306 3.3 2.2 55 81 2 2.2 17 28 6.5 22 Comparative Example 3 0.398 12 10 72 116 5.9 6.8 16 20 8 17 Comparative Example 4 0.373 3.3 2.2 58 81 2.1 2.2 17 25 6.1 20

Shout Softness Smoothness Abundance color
Uniformity Raising
Uniformity Total score Example 1 19 24 21 20 24 25 133 Example 2 20 21 19 21 24 25 130 Example 3 16 21 19 16 17 17 106 Comparative Example 1 9 16 16 11 12 11 75 Comparative Example 2 19 16 15 14 9 9 82 Comparative Example 3 21 11 16 9 11 11 79 Comparative Example 4 5 18 21 11 21 16 92

It can be seen from Table 2 that the artificial leather of the embodiment partially infiltrated the elastic body in the state of high density by shrinkage, high speed fluid and water treatment according to the present invention has improved appearance quality than the comparative example.

Claims (6)

In the manufacturing method of artificial leather,
Preparing a sea island type fiber through a composite spinning process;
Manufacturing a nonwoven fabric using the island-in-the-sea fibers;
Shrinking the nonwoven fabric;
Eluting the sea component of the contracted nonwoven fabric;
Manufacturing a high density nonwoven fabric by treating the nonwoven fabric from which the sea component is eluted with a high speed fluid;
Hydroprocessing the high density nonwoven fabric such that the water content of the high density nonwoven fabric is 10-30 wt%;
Coating a polymer elastomer on the back side of the water-treated high density nonwoven fabric:
Forming brushed on the surface of the nonwoven fabric in the coating step; manufacturing method of artificial leather. The method of claim 1,
The method of manufacturing artificial leather, characterized in that the step of shrinking the nonwoven fabric is passed through the nonwoven fabric in a boiling water of 80 ℃ or more for 5 minutes or more and pressed with a calendar. The method of claim 1,
The method of manufacturing artificial leather, characterized in that the treatment with the high-speed fluid is applied to the surface of the nonwoven fabric eluting the sea component to give a high pressure of the water pressure of 5 ~ 30 MPa and to absorb water from the back. delete The method of claim 1,
The method of manufacturing an artificial leather, characterized in that in the step of coating the polymer elastic body so that the polymer elastic body penetrates 30 to 70% in the thickness direction of the water-treated high-density nonwoven fabric. The artificial leather manufactured by the method of any one of claims 1 to 3 and 5, wherein the polymer elastic body is penetrated 30 to 70% in the thickness direction of the nonwoven fabric from the back side.

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