KR20180075906A - artificial leather with improved durability of abrasion and elasticity, and method of manufacturing the same - Google Patents

Abstract

The present invention relates to artificial leather with concurrently improved elasticity and wear resistance. The present invention provides a method for manufacturing the artificial leather, realized by adding an elastic body to non-woven fabric, forming napping, and performing a dyeing process, wherein the non-woven fabric is impregnated with polyurethane produced from ester based polyol, and again coated with polyurethane produced from polycarbonate based copolymer type polyol when the elastic body is added. The present invention can enhance emotional quality showing elasticity and texture similar to natural leather, and concurrently enhance wear resistance on the surface of the non-woven fabric.

Description

TECHNICAL FIELD The present invention relates to an artificial leather having improved elasticity and abrasion resistance at the same time and a method of manufacturing the artificial leather and an improved method of manufacturing the same.

The present invention relates to an elastic- Abrasion The properties of the artificial leather are improved at the same time.

Artificial leather is widely used in various fields such as shoes, clothes, gloves, miscellaneous goods, furniture and automobile interior materials.

When artificial leather is used as an automobile seat as an automobile interior material, the body of the driver is closely attached to the car seat for a long time, and the body of the driver rubs with the car seat from time to time according to the start, stop and change of direction during driving. Therefore, artificial leather for automobile seat is required to have excellent abrasion resistance on the surface, and general suede-like artificial leather has a problem in meeting the above requirements.

Accordingly, efforts to improve the quality of artificial leather have continued.

Korean Patent Laid-Open Publication No. 1987-0005144 describes a method for producing suede artificial leather excellent in rebound resilience and touch.

According to this patent, it is possible to provide a suede artificial leather excellent in rebound resilience and touch by impregnating a microfine nonwoven fabric with an elastic polymer substance, buffing and dyeing, and impregnating with a polyurethane prepolymer and post-processing.

However, the above process is carried out by specifically controlling the polyurethane component, which is an elastic substance, and an additional step of impregnating and crosslinking the polyurethane prepolymer is required, the elasticity of the polyurethane elastomer as a raw material must be improved, and a different type of polyurethane There is a problem.

Korean Patent Laid-Open Publication No. 1998-050077 discloses a method for producing non-woven artificial leather excellent in elasticity.

According to the patent, a method of improving the elasticity of the artificial leather and omitting the step of impregnating the polyurethane by adjusting the composition ratio of the polyester microfiber and the polyester polyurethane microfiber in the nonwoven fabric constituting the artificial leather is shown.

However, the above method is a method using an elastic blend yarn. When such a blend yarn is physically bonded to form a nonwoven fabric, there is a problem that the bonded fibers have a limitation in expressing elasticity in the nonwoven fabric.

Korean Patent Laid-Open Publication No. 2005-0116534 discloses an artificial leather excellent in abrasion resistance.

According to the patent, the coating resin layer containing spherical particles such as urethane resin and a resin such as polyurethane resin is formed on the surface of the artificial leather to improve the abrasion resistance by spherical particles, but the elasticity and texture of the artificial leather There is a problem of deterioration.

Korean Patent Publication No. 2006-0125162 discloses an artificial leather excellent in abrasion strength.

According to the patent, the surface of the artificial leather is coated with the silicone rubber to improve the abrasion resistance, but the artificial leather is difficult to manifest the suede effect due to the surface of the silicone rubber and the touch is deteriorated.

As described above, in order to improve the elastic property, the conventional technique is a method of improving the fiber or the elastic body constituting the nonwoven fabric and coating the surface of the nonwoven fabric to improve the abrasion resistance property. .

However, artificial leather for application to automobile seat is required to develop a technique for improving elasticity and abrasion resistance.

An object of the present invention is to provide a method for producing an artificial leather, in which a method of imparting a specific polyurethane elastomer to a nonwoven fabric is improved to cope with the above-mentioned demand, whereby the elasticity property and the abrasion resistance property are improved.

In order to solve the above problems, the present invention provides a method for fabricating a non-woven fabric comprising the steps of impregnating a nonwoven fabric formed of sea-island conjugate fibers with a polymeric elastomer, finely segregating the marine-type conjugate fiber by elution, A method for producing an artificial leather including dyeing a nonwoven fabric, comprising the steps of: impregnating the nonwoven fabric with polyurethane produced from an ether-based polyol as an elastic substance at the time of impregnation; and subsequently impregnating the nonwoven fabric with a polyurethane The present invention also provides a method for producing an artificial leather characterized in that elasticity and wear resistance are simultaneously improved by coating polyurethane.

The present invention also provides an artificial leather which is produced by the above method and has a tensile elasticity of 60 to 70% and a peelability of not less than grade 4 (Martindale Peeling Tester, load of 600 g) .

INDUSTRIAL APPLICABILITY According to the present invention, by using an elastic body applying method for coating a polyurethane produced from a polycarbonate-based copolymerizable polyol on the surface of a nonwoven fabric after impregnating the nonwoven fabric with a polyurethane produced from an ether-based polyol, It becomes possible to improve the wear resistance characteristic at the surface of the nonwoven fabric while being similar to the natural leather.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a manufacturing process for imparting an elastic body to a nonwoven fabric according to the present invention. Fig.
Fig. 2 is a schematic view showing a lubrication measuring apparatus for evaluating elasticity characteristics of an artificial leather. Fig.
Fig. 3 is a photograph of a Taber abrasion strength measuring instrument for evaluating the abrasion resistance of artificial leather and the result of evaluation using the same.
4 is a photograph of a Martindale pilling tester for evaluating the pilling property of artificial leather and the result of evaluation using the Martindale pilling tester.

The present invention relates to a method for producing an artificial leather comprising impregnating a nonwoven fabric formed of sea-island conjugate fibers with a polymeric elastomer, finely finishing the sea-island conjugate fiber by elution, grinding the surface of the nonwoven fabric and dyeing the nonwoven fabric Impregnating the nonwoven fabric with the polyurethane produced from an ether-based polyol as an elastic substance at the time of impregnation, and then coating the surface of the nonwoven fabric with a polyurethane produced from a polycarbonate-based copolymerizable polyol And a method for producing the same.

Polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyamide or the like is used as a component of the sea-island complex fiber used in the present invention. As the sea component, polystyrene having an alkali- Polyethylene, modified polyester, copolymerized polyester and the like can be used.

The nonwoven fabric of the present invention can be produced by shortening the sea-island type conjugate fiber, forming the short fiber into a multi-layer web, and needle-punching the web.

In the present invention, the method of impregnating the nonwoven fabric with the elastomeric polymer includes immersing the nonwoven fabric in a polyurethane solution for impregnation in which polyurethane is dissolved in an organic solvent such as dimethylformamide (DMF), taking out the nonwoven fabric from the impregnating polyurethane solution Squeezing and squeezing with a press roll, coating the surface of the nonwoven fabric with a coating polyurethane solution, coagulating the polyurethane, and washing with water.

At this time, the polyurethane used in the impregnation polyurethane solution is a polyurethane produced from an ether-based polyol, and the polyurethane used in the coating polyurethane solution is preferably a polyurethane produced from a polycarbonate-based copolymerization-type polyol .

The polyol component of the polyurethane produced from the ether-based polyol is preferably an ether-based polyol such as polypropylene glycol (PPG), polytetramethylene ether glycol (PTMEG), or polyethylene glycol (PEG) The polyurethane imparts elasticity and flexibility in artificial leather and exhibits a texture similar to that of natural leather, so that the quality of sensibility can be improved. In the present invention, the use of a polyurethane prepared from polytetramethylene ether glycol is more preferable because it can improve hydrolysis resistance and low temperature characteristics.

When the nonwoven fabric is squeezed and squeezed, it is preferable to control the impregnation amount by performing the pressing at a pressure of 1 to 3 kgf / cm 2 and the gap between the mangles at 70 to 80% relative to the nonwoven fabric.

The artificial leather produced by impregnating with only the polyurethane produced from the ether-based polyol remarkably improves the emotional quality, but the mechanical properties are insufficient, so that it can be mainly used only for articles such as bags and clothes.

In the present invention, the polyurethane produced from the polycarbonate-based copolymerization-type polyol is coated on the surface of the nonwoven fabric after the immersion and compression bonding, and the polyurethane produced from the ether-based polyol in the artificial leather, And light resistance and heat resistance, and can be applied to artificial leather for automobile seat.

The polyol component of the polyurethane used in the coating may be a polycarbonate-based polyol represented by the following general formula (1). Generally, the diol component is 1,4-butanediol (BD), 1,5- Or 1,6-hexanediol (HD).

HO- [ROCOO] _n- R-OH

However, polyurethane made from polycarbonate-based polyol having such a short carbon chain has poor molecular mobility and hardness and stiffness are increased in artificial leather, making it difficult to improve emotional quality.

Accordingly, in the present invention, the polyol portion is formed by using a copolymer of 1,4-BD and 1,5-PD or a copolymer of 1,5-PD and 1,6-HD, The quality of the emulsion can be improved by the carbon chain extended by the copolymer while improving abrasion resistance, heat resistance, light resistance, chemical resistance, transparency and mechanical strength in leather.

Wherein the coating is a coating solution prepared by dissolving a polyurethane prepared from a polycarbonate-based copolymerization-type polyol in dimethylformamide, wherein the solid content of the polyurethane prepared from the polycarbonate-based copolymerization-type polyol in the coating solution is 16 to 20 wt% And has a viscosity of 2000 ± 200 cps (25 ° C.), and can be coated using a knife coating method, a comma coating method, a bar coating method, a roll coating method or the like.

The amount of coating in a wet state may be 50 to 80 parts by weight based on 100 parts by weight of the nonwoven fabric in terms of the texture of the artificial leather, and the amount of coating after drying is preferably 10 to 20 parts by weight relative to 100 parts by weight of the nonwoven fabric.

As a method for removing the sea component from the sea-island complex fiber for making the sea-island composite fiber finer, there is a method of treating the non-woven fabric with a solvent or a decomposing agent capable of selectively removing the sea component, When an alkaline soluble modified polyester is used as a sea component, an alkaline decomposing agent such as an aqueous solution of sodium hydroxide is preferably used.

In the present invention, a caustic soda aqueous solution of 1 to 20% by weight is used as the alkaline decomposing agent, and the time of the decaying time is preferably 5 to 30 minutes.

The fineness of the metallic component after the microfabrication of the present invention is 0.3 denier or less, which is good for improving the flexibility and surface appearance of the artificial leather. In addition, this enables the superfine fibers to interlock with each other three-dimensionally after the microfabrication process to prevent the drop in strength.

After the microfabrication, the heat-treated nonwoven fabric is ground with abrasive paper (sand paper or the like) to form a standing hair on the surface of the nonwoven fabric, and is dyed in a desired color using a conventional method.

The present invention relates to a nonwoven fabric in which polyurethane produced from an ether-based polyol is impregnated as an elastic material in the interior of a nonwoven fabric, and the surface of the nonwoven fabric is coated with polyurethane produced from a polycarbonate- It is possible to satisfy the properties required particularly in leather.

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. It is to be understood, however, that the following examples and comparative examples are given for the purpose of illustration only and are not to be construed as limiting the scope of the present invention. It is to be understood that within the scope of the present invention, It will be apparent to those skilled in the art that the present invention may be practiced.

[Example 1]

A nonwoven fabric in which sea water (51 mm in fiber length) having alkali soluble polyester as a sea component and polyethylene terephthalate (PET) as a component was self-entangled was prepared.

Polyurethane (resin solid content 30%, hereinafter referred to as PU-1) obtained by reacting polytetramethylene ether glycol (PTMEG-2000) with methylene diphenyl isocyanate (MDI) was diluted with dimethylformamide, Wt% impregnation solution was prepared.

Polyurethane (resin solid content 30%, hereinafter referred to as PU-2) obtained by reacting a polycarbonate copolymerizable polyol (polyol T-5652, Asahi Kasei, Japan) with methylene diphenylisocyanate (MDI) was diluted in dimethylformamide Thereby finally preparing a coating liquid having a resin solid content of 18% by weight.

The step of immersing the nonwoven fabric in the impregnation solution to impregnate the polyurethane made of the ether polyol and then compressing was carried out under the conditions of a pressure of 2 kgf / cm 2 and a spacing between the mangles of 70% So that the amount of impregnation after compression in the wet state was 100 parts by weight relative to 100 parts by weight of the nonwoven fabric.

Then, the surface of the impregnated nonwoven fabric was coated with the coating liquid. At this time, the coating was coated with the coating liquid by a knife method while coating the coating liquid in a wet state with 80 parts by weight of the coating liquid relative to 100 parts by weight of the nonwoven fabric while closely adhering the nonwoven fabric with the knife.

Thereafter, the elastic solid was coagulated and washed with an aqueous solution containing 20% by weight of dimethylformamide in the coagulation bath, and then dried in a hot-air drier at 120 ° C for 10 minutes. The solid content of the coating liquid impregnated into the non- 14 parts by weight of an elastomer-imparting nonwoven fabric.

Subsequently, the elastic material-imparting nonwoven fabric was treated with a 10 wt% caustic soda aqueous solution to elute the alkali-soluble polyester as a decomposition product to prepare a microfine nonwoven fabric having a density of 0.3 denier or less.

Thereafter, the nonwoven fabric was subjected to thermal calendering using a roll heated to 130 DEG C, and the surface of the nonwoven fabric was grinded using roughness # 150 sandpaper to form bristles. Then, using a disperse dye, Dyed in a dyeing machine, and then cleaned to prepare an artificial leather.

[Comparative Examples 1 to 5]

In Example 1, except for using the polyurethane for impregnating liquid and the polyurethane for coating liquid shown in Table 1 below, Example 1 Artificial leather was produced using the same method.

Impregnated polyurethane Polyurethane for coating liquid Example 1 PU-1 PU-2 Comparative Example 1 PU-1 × Comparative Example 2 PU-2 × Comparative Example 3 PU-1 PU-1 Comparative Example 4 PU-2 PU-2 Comparative Example 5 PU-1 PU-3 * 1) × indicates no coating
2) PU-3: Polyurethane (polyurethane) produced by Kolon Oil & Co., Ltd. with a solid content of 30% by weight of polycarbonate polyol (polyol portion is 1,6-hexanediol (polypl T-6002, Asahi Kasei, Japan)

The properties of the artificial leather prepared in the above Examples and Comparative Examples were evaluated according to the following evaluation methods, and the results are shown in Table 2 below.

1. Tensile Elasticity

The tensile modulus of an artificial leather sample is measured in an Instron tensile recovery machine. The higher the tensile elasticity index (RT) is, the higher the recovery rate after stretching is.

2. Lecture

Prepare test specimens with a width of 25 mm and a length of 200 mm.

Using a measuring apparatus as shown in Fig. 2, the specimen was slid at a speed of 10 mm / sec in the direction of the slope by pushing the specimen with a pressure plate of the same size as the specimen on a smooth horizontal base having a slope of 45 ° at one end, The position (B) of the other end when one end of the test piece is in contact with the inclined surface is measured, and the moving distance (mm) between (A) and (B) is shown as a lecture diagram as shown in Fig.

The higher the lubrication index, the more excellent the shape stability and the better the elastic properties of the artificial leather. However, if the slope is more than 90mm, it becomes stiff.

3. Smooth characteristics

The softness index is compared and evaluated using the ST-300 softness measuring device.

The higher the softness index, the smoother the grip of artificial leather, which improves the sensibility of artificial leather.

4. Abrasion resistance

Using a Taber abrasion tester, the sample was placed and rotated 5,000 times with a load of 1 kg each with a CS-10 grinding wheel to calculate the weight of the initial sample as a percentage of the weight of the initial sample, and the surface of the artificial leather The abraded area is evaluated on a gray scale (see Fig. 3).

The lower the weight reduction rate and the higher the gray scale water number, the better the abrasion resistance.

5. Pilling property

Using a Martindale pilling tester, the sample is protruded from the surface and contacted with a white cotton cloth at a load of 600 g. After rotating 12,000 times, the degree of change of the surface due to napping is visually confirmed and evaluated in gray scale (See FIG. 4).

The higher the rated water content, the better the surface friction resistance.

6. Light Resistance

The light fastness after light irradiation is comparatively evaluated by grayscale through Xenon-Arc test.

The higher the water supply, the better the light resistance.

7. Heat resistance

The sample is heated at 125 ° C for 60 minutes, and the color change rate of the surface is compared with ΔL, Δa, Δb, and ΔE values by a CCM (Computer Color Matching) colorimeter.

The higher the Δ value, the greater the color change. If the ΔE value is greater than 1.0, the color difference is noticeable to the naked eye.

division Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Tensile Elasticity (RT,%) 64.8 42.2 46.6 63.7 32.6 28.4 Lecture (mm) 53 38 47 55 88 126 Softness (mm) 4.1 3.8 3.4 4.2 3.0 2.8 Abrasion resistance Weight reduction rate (%) 0.65 11.84 4.78 7.43 0.44 0.63 Grayscale (grade) 4 2 3 2.5 4 4 Pilling Castle Grayscale (grade) 4 2 3 2.5 4 4.5 Light resistance Grayscale (grade) 4 2.5 3.5 2 4 4 Heat resistance ΔL -0.30 -1.22 -0.44 -1.33 -0.27 -0.44 Δa -0.02 -0.23 -0.06 -0.25 +0.01 -0.04 Δb +0.03 -0.05 +0.05 -0.07 +0.07 +0.03 ΔE +0.30 +1.24 +0.44 +1.35 +0.28 +0.45

From the above Table 1, it was confirmed that the artificial leather according to Example 1 has the same tensile elasticity, lubrication and softness as those of the comparative example, so that it can exhibit the same effect as natural leather which is soft and not stiff but has moderate elasticity do.

In addition, the artificial leather according to Example 1 is superior in wear resistance, pilling property, light resistance and heat resistance as compared with the comparative example, and thus it can be confirmed that it can be sufficiently used for automobile seat. Particularly, when the artificial leather is applied to an automobile seat due to improved pilling properties, damage to the surface of the seat can be improved even if the driver's body rubs on the seat for a long time.

Claims (5)

A method for producing artificial leather including impregnating a nonwoven fabric formed of sea-island conjugate fibers with a polymeric elastomer, finely finishing the sea-island composite fibers by elution, grinding the surface of the nonwoven fabric to form bristles, and dyeing the nonwoven fabric Wherein the impregnation is carried out by impregnating the nonwoven fabric with a polyurethane produced from an ether-based polyol as an elastic substance, and then coating the surface of the nonwoven fabric with a polyurethane produced from a polycarbonate-based copolymerizable polyol. A method for producing an artificial leather having improved elasticity and wear resistance at the same time. The method according to claim 1,
Wherein the ether-based polyol is selected from polypropylene glycol, polytetramethylene ether glycol, and polyethylene glycol, wherein the elasticity property and the abrasion resistance property are improved at the same time. The method according to claim 1,
The polycarbonate copolymerizable polyol is characterized in that the polyol portion is a copolymer of 1,4-butanediol and 1,5-pentanediol or a copolymer of 1,5-pentanediol and 1,6-hexanediol , The elasticity characteristic and the abrasion resistance property are improved at the same time. The method according to claim 1,
The amount of the coating in the wet state is 50 to 80 parts by weight based on 100 parts by weight of the nonwoven fabric and the amount of the coating in the dry state is 10 to 20 parts by weight relative to 100 parts by weight of the nonwoven fabric Wherein the elasticity property and the abrasion resistance property are improved at the same time. A process for producing a polyurethane foam which is produced by the process of any one of claims 1 to 4 and which has a tensile elasticity of 60 to 70% and a peelability of not less than grade 4 (Martindale Peeling Tester, load of 600 g) Artificial leather.

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