JPH10168763A - Production of sueded artificial leather - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a sueded artificial leather, having a dense surface, full of a high-class feeling and useful as a handbag, etc., by deforming a specific nonwoven fabric under specific conditions and fixing the deformed nonwoven fabric. SOLUTION: This method for producing a sueded artificial leather comprises (A) a step for forming a conjugated fiber capable of being ultrafine fibers of <=0.2 denier size into a nonwoven fabric, (B) an impregnation and coagulation step for impregnating the nonwoven fabric with a polyurethane solution, coagulating the solution and providing a substrate, (C) an extraction step for extracting one component of the conjugated fiber constituting the nonwoven fabric from the substrate and providing an extracted substrate, (D) an extracted substrate fixing step for coating the surface of the extracted substrate with a polyurethane solution and (E) a napping step for polishing the coated surface. The extracted substrate is deformed so as to provide a value within the range satisfying the formula (La , and Wa are each the length and width of the nonwoven fabric obtained in the step A; Lc and Wc are each the length and width of the extracted substrate obtained in the step C) and the deformed state thereof is then fixed in the step D to afford the sueded artificial leather. The density of the nonwoven fabric prepared in the step A is preferably 0.25-0.40g/cm<3> .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing suede-like artificial leather. More specifically, in a method for producing suede-like artificial leather using ultrafine fibers,
The present invention relates to a method for producing artificial leather having a dense artificial leather surface and free from defects such as needle holes caused by needle punching.

[0002]

2. Description of the Related Art Suede-like artificial leather is expected to be used for clothing, especially for women, because of its high-class appearance. Numerous methods have been proposed as methods for producing such suede-like artificial leather. For example, Japanese Patent Publication No. 59-27418 discloses that an impregnated entangled nonwoven fabric composed of a multicomponent fiber and a rubber elastic polymer which is made fine by extraction is dispersed in a solvent which swells and contracts the rubber elastic polymer. A method for obtaining a suede-like artificial leather by dissolving and removing a medium component to form an ultrafine fiber and buffing the surface is described. However, in the artificial leather obtained by this method, defects such as eye holes and needle holes become noticeable after piloerection, particularly after dyeing, due to defects of needle holes due to needle punching at the time of producing a nonwoven fabric and uneven density.

Japanese Patent Publication No. 61-32432 discloses a method of applying a solvent for an elastic polymer to the surface of a suede-like sheet made of a fibrous material and an elastic polymer and having been subjected to a nap treatment to re-solidify the elastic polymer. Have been described. However,
The purpose of this method is to tighten with an elastic polymer in order to prevent the surface raised fibers of the raised sheet from falling off, and there is no description of a method for obtaining suede-like artificial leather having no defects such as surface needle holes.

Further, Japanese Patent Application Laid-Open No. Hei 7-126985 discloses that
A web is made using ultrafine composite fibers composed of more than one type of high-molecular polymer, the web is impregnated with an elastic polymer, and the obtained base material is squeezed to 60 to 90% and solidified. , Making the conjugate fiber ultrafine, applying a solution containing a solvent of the elastic polymer to the non-pilfered surface of the substrate, and dissolving or swelling a part of the elastic polymer, and then solidifying the liquid-treated surface. A method of obtaining a nubuck-like artificial leather by buffing is described. However, although this method is effective in shortening the bristle of the nap fiber, it does not solve the drawback of the needle hole due to the needle punch on the artificial leather surface.

[0005] As described above, the suede-like artificial leather obtained by the conventional method is inferior in the quality of the surface and is insufficient.

[0006]

SUMMARY OF THE INVENTION The present invention solves the problems of the prior art and provides a suede-like artificial leather having an excellent surface appearance which can be used for high-grade women's clothing such as handbags and women's pumps. It is intended for.

[0007]

That is, the present invention relates to the following (A) to (E): (A) a nonwoven fabric step of forming a composite fiber which can be ultrafinely reduced to 0.2 denier or less; Impregnating with a polyurethane solution and then solidifying the polyurethane to form a base material; and (C) extracting one component of the conjugate fiber constituting the nonwoven fabric from the base material to form an extraction base material. (D) an extraction substrate fixing step of applying a polyurethane solution or a polyurethane solvent to the surface of the extraction substrate,
(E) a method of producing a suede-like artificial leather, which comprises the step of raising the coated surface, wherein the length / width value of the extraction base material obtained in the extraction step is (A) a nonwoven fabric The value of the length / width of the nonwoven fabric obtained in the process is expressed by the following formula (I)

[0008]

(Equation 2)

[Where La and Wa are the length and width of the nonwoven fabric obtained in the nonwoven fabric step (A);
And Wc are the length and width of the extraction substrate obtained in the extraction step (C). ], And then fix the deformed state by an extraction base material fixing step (D) to produce a suede-like artificial leather.

Hereinafter, the present invention will be described in detail.
There is no particular limitation on the composite fiber that can be made ultrafine to 0.2 denier or less used in the nonwoven fabric step (A) of the present invention, as long as it is composed of an extracted component and a non-extracted component. Is a polyolefin.
Specific examples of the polyolefin include polyethylene, polypropylene, polystyrene and the like.
Polyethylene is preferred in terms of cost. Particularly, it is preferable to use polyethylene having a density of 0.93 g / cm ³ or less from the viewpoint of high solubility in a solvent. Examples of the non-extractable component include polyamide and polyester. Specific examples of polyamides include nylon 6, nylon 6,6,
Nylon 6, 10, Nylon 12, and the like. Specific examples of the polyester include polyethylene terephthalate and polybutylene terephthalate. A preferred combination as the composite fiber is a combination of a polyolefin and a polyamide, and a particularly preferred combination is a combination of a polyethylene and a nylon 6. Although there is no particular limitation on the form of the composite fiber, examples thereof include a split type and a sea-island type, and a sea-island type is preferable.

As a method for forming the above-mentioned conjugate fiber into a nonwoven fabric, a conventionally known method can be used. For example, a conjugate fiber is used as raw cotton, a web is formed by a card, a random weber, a cross layer, or the like, and the obtained web is subjected to needle punching to form a nonwoven fabric. The needle punching is performed in the thickness direction of the nonwoven fabric, and 500 to 3000
Book / cm ² , preferably 800 to 2000 book / cm ² . If the number of needle punches is less than 500 needles / cm ² , the entangled state of the obtained nonwoven fabric is not sufficient, and 3000 needles / c
If it is more than m ^2, the fibers constituting the nonwoven fabric are damaged, and the surface irregularities of the obtained nonwoven fabric become too large, such being undesirable. The needle used in the present invention should be appropriately selected from the broken needle and the entanglement efficiency, but generally, a needle having a barb number of 1 to 9 can be preferably used.

The density of the obtained nonwoven fabric is 0.25
It is preferably in the range of 〜0.40 g / cm ³ .

Next, the nonwoven fabric obtained in the nonwoven fabric step (A) is impregnated with a polyurethane solution, and then the polyurethane is solidified to form a base material (impregnation / solidification step (B)). It is preferable that the above nonwoven fabric is heated in a heating zone before the polyurethane impregnation, and is impregnated with the following polyurethane and solidified by nipping and fixing with a metal roll.

The polyol component of the polyurethane used here includes, for example, polyether type, polyester type, and polycarbonate type, and the isocyanate component includes, for example, diphenylmethane diisocyanate, tolylene diisocyanate, and isophorone diisocyanate. As the polyurethane used in the present invention, all of these combinations can be selected and used depending on the application. For example, in view of physical properties and toluene resistance, it is preferable to use diphenylmethane diisocyanate polyurethane. Further, a polyurethane containing no polyoxyethylene ether component and a polyurethane containing a polyoxyethylene ether component can be appropriately mixed and used. By containing the above polyoxyethylene ether component in an amount of 1 to 30% based on the weight of the polymer,
The dyeability of the obtained substrate is improved, and the substrate can be dyed in a dark color. Further, the 100% modulus of the polyurethane used in the present invention preferably satisfies the range of 40 to 110 kg / cm ² . Here, when the 100% modulus of the polyurethane is lower than 40 kg / cm ² , the solvent resistance decreases, and when it exceeds 110 kg / cm ² , the feeling of the artificial leather obtained is undesirably hard.

The polyurethane is generally applied by dissolving it in an organic polar solvent such as dimethylformamide, diethylformamide, dimethylacetamide, dimethylsulfoxide and tetrahydrofuran. In addition, water, alcohol, methyl ethyl ketone, and the like can be used as a mixture with these organic polar solvents. The amount of polyurethane impregnated is 20 to 50% of the solid content of polyurethane based on the nonwoven fabric.
It is preferred that 20% polyurethane impregnation
If the amount is less, the obtained artificial leather becomes paper-like, the flexibility is insufficient, and if it is more than 50%, the obtained artificial leather becomes rubber-like and hard.

Further, after the polyurethane is impregnated, it is preferable to squeeze to about 70% of the thickness of the substrate in order to remove excess polyurethane resin adhering to the surface of the nonwoven fabric.

Next, the impregnated polyurethane is coagulated. As the coagulation method, it is preferable to use a wet coagulation method because the obtained artificial leather becomes soft.

In the extraction step (C), one component of the composite fiber constituting the nonwoven fabric is extracted from the obtained base material,
The composite fiber is made extremely fine and used as an extraction substrate. The extraction solvent used here is not particularly limited as long as it dissolves polyolefin and does not dissolve polyamide, polyester and polyurethane. Specifically, general-purpose solvents such as toluene, xylene, and trichlene are exemplified,
From the viewpoint of recovery, toluene is preferred. When toluene is used, it is particularly preferable to use toluene at 80 ° C. or higher.

Here, the feature of the present invention is that the length / width value of the extraction base material is expressed by the following formula (I) with respect to the length / width value of the nonwoven fabric obtained in the nonwoven fabric step (A).

[0020]

(Equation 3)

[Where La and Wa are the length and width of the nonwoven fabric obtained in the nonwoven fabric step (A);
And Wc are the length and width of the extraction substrate obtained in the extraction step (C). ] In such a range as to satisfy the range. By deforming in this way, the needle needle hole on the surface of the extraction base material is deformed and becomes less noticeable.

The deformation method is achieved by applying a tension in the length direction to the obtained extraction base material.
The magnitude of the tension applied to the extraction base material varies depending on the basis weight of the nonwoven fabric constituting the extraction base material to be used, the 100% modulus of polyurethane, the impregnation concentration of polyurethane, and the like. It is preferable to perform the deformation before the extraction substrate fixing step (D), and it is particularly preferable to perform the deformation simultaneously with the extraction in the extraction step (C).

Here, if the value of the formula (I) is smaller than 1.4, the needle holes of the extraction base material are not so deformed, and the needle holes are not concealed after polishing, especially after dyeing, resulting in poor quality. . When the value of the formula (I) is larger than 1.8, the needle hole is almost vertically elongated and cannot be seen, but on the contrary, the extraction base material has vertical wrinkles and the appearance is deteriorated.

By setting the value of the formula (I) to 1.4 to 1.8, the following can be considered as a factor for reducing the needle hole defect. Since polyurethane is swelled to some extent by the extraction solvent through the extraction process, when tension is applied in the length direction of the extraction base material, it is elongated in the vertical direction and contracted in the horizontal direction, thereby causing the extraction base material to shrink. It is considered that the needle hole is deformed and the shape of the needle hole changes from circular to linear. Further, it is conceivable that the adhesion between the ultrafine fiber and the polyurethane is released due to the ultrafineness of the conjugate fiber, and the fiber is oriented in the vertical direction to cover the needle hole.

Next, as a method for separating the solvent from the extraction base material, a wet method, a dry method and the like can be adopted. Thereafter, the deformed extraction base material is dried, and the extraction base material fixing step (D)
Is applied. This is a step necessary for fixing the deformed state of the extraction base material. Without the extraction substrate fixing step (D), the deformed needle hole returns to its original shape again in a post-process such as dyeing, even if it is maintained in the napping process.

Here, in the extraction substrate fixing step (D), a polyurethane solution or a polyurethane solvent is applied to the surface of the obtained extraction substrate. The immobilization of the extraction substrate is carried out by applying a polyurethane solution to the surface of the obtained extraction substrate and then solidifying by providing a coating layer, or by applying a polyurethane solvent to the surface of the obtained extraction substrate, It can be performed by a method of dissolving and re-solidifying the polyurethane on the surface of the extraction base material. The same polyurethane solution as that used in the above-mentioned impregnation step (B) can be used. As a solvent for polyurethane,
Examples include dimethylformamide, dimethylacetamide, diethylformamide, dimethylsulfoxide, dioxane, tetrahydrofuran, cyclohexanone and the like.

The coating method can be performed using a gravure roll, a gravure coater, a spray, or the like, but it is preferable to use a gravure roll while nipping the extraction base material.

The amount of the polyurethane solution or polyurethane solvent applied to the surface of the extraction substrate may be an amount necessary for fixing the ultrafine fibers and the polyurethane on the surface of the substrate, and is 10 to 60 g / m 2. It is preferably ² .

The obtained immobilized base material is napped by polishing the coated surface (napping step (E)). As a polishing method, a conventionally known method is used. For example, polishing paper or the like is used. When using abrasive paper, the size of the mesh is selected according to the desired length of the nap. For example, when a short nap is desired, a fine mesh is selected, and when a long nap is desired, a coarse mesh is selected. Usually, it is polished 1 to 3 times using a sandpaper of 150 to 800 mesh as needed for use or necessity.

The immobilized substrate can be sliced before or after the raising step (E). Slicing makes it possible to use both sides of the suede-like artificial leather surface obtained by the above process, which is preferable.

Further, since the fibers are cut on the slice surface, the fibers fall off and the surface is roughened, and the commercial value is reduced. Therefore, it is necessary to apply a polyurethane solution to the slice surface to fix the fibers and the polyurethane.
This is to fix the fiber and polyurethane, so that the morphological change does not occur in the subsequent dyeing process and kneading process, the amount of polyurethane solution applied to the slice surface is as small as possible within the range to achieve the purpose Better.

The artificial suede leather obtained from the above steps (A) to (E) can be further subjected to a dyeing treatment, a softener and / or a water repellent treatment, a kneading treatment and the like according to the purpose.

For the dyeing treatment, for example, when the fiber is a polyamide, 8 is obtained by using an acid dye in combination with a gold-containing dye.
It can be dyed at 0 ° C. or higher. When the fiber is polyester, high-pressure dyeing can be performed using a disperse dye. Examples of the dyeing method include a circular method, a Jigger method, a Wins method, and a pad-sick method, which are appropriately selected depending on the use of the artificial leather and the lot size. It is preferable to use the circular method from the viewpoint of uniformity and stability of dyeing of the artificial leather surface.

The kneading process can be performed using, for example, a flexible processing machine called a tumbler. The kneading treatment using a tumbler is performed in a heated state, specifically, 50 to 130 ° C.
It is preferable to carry out in. Further, in the kneading treatment by this method, since the tension is not applied in the length direction and the width direction of the artificial leather, the texture of the obtained artificial leather is very soft. Further, by performing the kneading treatment, the tension state accumulated in the longitudinal direction of the base material can be released by the tension applied for the deformation after the extraction step. In addition, in order to simultaneously perform the drying after the dyeing treatment and the kneading treatment, it is possible to use a method in which the artificial leather is transported by an air flow in the length direction of the artificial leather. This method is preferable because the physical properties of the obtained artificial leather in the longitudinal direction can be improved. After the rubbing treatment, it is preferable to appropriately apply a brush to the surface of the artificial leather to perform hair styling and the like.

[0035]

The present invention will be described in more detail with reference to the following examples.

[Example 1] A nylon 6 chip and a polyethylene chip having a density of 0.915 g / cm ³ were mixed with 5 chips.
The mixture was melt-mixed and spun at a ratio of 0:50, stretched, crimped, and cut to prepare a raw cotton having a cut length of 51 mm. Laminated with card and cross layer, 1 with 3 barb needle
Needle punching was performed at a needle density of 400 needles / cm ² to prepare a nonwoven fabric having a basis weight of 570 g / m ² and a thickness of 2.5 mm.
The nonwoven fabric was heated by a dryer at 150 ° C., cooled and nip with a metal roll at 90 ° C., and fixed. The obtained nonwoven fabric had a basis weight of 565 g / m ² , a thickness of 1.75 mm, and a density of 0.
33 g / cm ³ , length 250 m, width 1.52 m, length (La) / width (Wa) 164. (Non-woven fabric process (A))

Next, the nonwoven fabric was impregnated with a polyurethane solution. The polyurethane solution used was a polyurethane having a 100% elongation modulus of 70 kg / cm ² , and 14% polyurethane, 7% polyoxyethylene ether, and dimethylformamide (hereinafter, “DMF”) containing a coagulation regulator.
That. ) Solution. The impregnation amount is 900 g / m ² and the substrate surface is squeezed to 70% of the substrate thickness,
After removing the excess polyurethane resin, a 10% D
The MF solution was coagulated in a water bath and dried at 140 ° C. (Impregnation step (B))

The resulting substrate was repeatedly dipped and nipped with toluene at 80 ° C. to extract polyethylene. At the same time as the extraction, the entire width of the substrate was deformed by applying a tension of 5 to 10 kg, and then dried. The basis weight of the extraction base material was 440 g / m ² , length 310 m, width 1.18 m, and length (Lb) / width (Wb) 263. (Extraction step (C)) The value of the formula (I) was 1.60.

Using a 200 mesh gravure roll, two polyurethane DMF solutions were applied to the surface of the deformed extraction substrate. (Extraction substrate fixing step (D))

After drying, the coated surface was polished with a 320-mesh sandpaper to obtain a suede-like artificial leather whose surface was covered with fine ultrafine nylon fibers. (Nailing process (E))

The artificial leather was placed 0.45 from the surface in the longitudinal direction.
Sliced at mm. One roll of a mixed solution (DMF / MEK = 70/30) of DMF and methyl ethyl ketone (hereinafter, referred to as “MEK”) was applied to the slice surface using a 200 mesh gravure roll.

Further, the artificial leather was dyed in a wine color using a gold-containing dye. The surface of the obtained artificial leather was dense and had no defects based on the needle holes and was of high quality. However, since it was slightly paper-like, rubbing treatment was performed at 130 ° C. for 30 minutes using a tumbler rubbing machine. The resulting suede-like artificial leather had a dense surface, no defects due to needle holes, and was of high quality, and was also flexible and supple, and had good slimy feeling and chalk mark property.

When the artificial leather was cut and finished as a jacket and worn, it was found to be excellent in lightness, softness and appearance with quality.

[Example 2] A nylon 6 chip and a polyethylene chip having a density of 0.915 g / cm ³ were mixed with 5 chips.
The mixture was melt-mixed and spun at a ratio of 0:50, stretched, crimped, and cut to prepare a raw cotton having a cut length of 51 mm. Laminated with card and cross layer, 1 with 3 barb needle
Needle punching was performed at a needle density of 400 needles / cm ² to prepare a nonwoven fabric having a basis weight of 575 g / m ² and a thickness of 2.5 mm.
The nonwoven fabric was heated by a dryer at 150 ° C., cooled and nip with a metal roll at 90 ° C., and fixed. The obtained nonwoven fabric had a basis weight of 567 g / m ² , a thickness of 1.90 mm, and a density of 0.
30 g / cm ³ , length 251 m, width 1.52 m, length (La) / width (Wa) 165. (Non-woven fabric process (A))

Next, the nonwoven fabric was impregnated with a polyurethane solution. The polyurethane solution used was a polyurethane having a 100% elongation modulus of 110 kg / cm ² , and 10% of polyurethane, 7% of polyoxyethylene ether,
Dimethylformamide containing a coagulation regulator (hereinafter referred to as “DM
F ". ) Solution. The impregnation amount is 920 g / m ²
After squeezing the surface of the substrate to 70% of the thickness of the substrate to remove excess polyurethane resin,
Was coagulated in a water bath of a DMF solution and dried at 140 ° C.
(Impregnation step (B))

The obtained substrate is repeatedly dipped and nipped with toluene at 80 ° C., and polyethylene is extracted. At the same time as the extraction, the whole substrate width is deformed by applying a tension of 5 to 10 kg, and then dried. did. The basis weight of the extraction base material was 420 g / m ² , length 290 m, width 1.25 m, and length (Lb) / width (Wb) 232. (Extraction step (C)) The value of equation (I) was 1.41.

Two rolls of a polyurethane DMF solution were applied to the surface of the deformed extraction substrate using a gravure roll of 200 mesh. (Extraction substrate fixing step (D))

After drying, the coated surface was polished with a 320 mesh sandpaper, and further polished with a 400 mesh sandpaper. A suede-like artificial leather with a fine ultrafine nylon fiber raised on the surface was obtained. (Nailing process (E))

The resulting artificial leather was dyed blue using a gold-containing dye. The surface of the obtained artificial leather was dense and had no defects based on the needle holes and was of high quality. However, since it was slightly paper-like, rubbing treatment was performed at 130 ° C. for 30 minutes using a tumbler rubbing machine. The resulting suede-like artificial leather had a dense surface, no defects due to needle holes, and was of high quality, and was also flexible and supple, and had good slimy feeling and chalk mark property.
When the artificial leather was cut and finished as a handbag, it was excellent in luxury.

Comparative Example 1 A chip of nylon 6 and a chip of polyethylene having a density of 0.915 g / cm ³ were mixed with 5
The mixture was melt-mixed and spun at a ratio of 0:50, stretched, crimped, and cut to prepare a raw cotton having a cut length of 51 mm. Laminated with card and cross layer, 1 with 3 barb needle
Needle punching was performed at a needle density of 400 needles / cm ² to prepare a nonwoven fabric having a basis weight of 650 g / m ² and a thickness of 3.5 mm.
The nonwoven fabric was heated by a dryer at 150 ° C., cooled and nip with a metal roll at 90 ° C., and fixed. The obtained nonwoven fabric had a basis weight of 655 g / m ² , a thickness of 2.30 mm, and a density of 0.3.
28 g / cm ³ , length 200 m, width 1.52 m, length (La) / width (Wa) 132. (Non-woven fabric process (A))

Next, the nonwoven fabric was impregnated with a polyurethane solution. The polyurethane solution used was a polyurethane having a 100% elongation modulus of 110 kg / cm ² , and 10% of polyurethane, 7% of polyoxyethylene ether,
Dimethylformamide containing a coagulation regulator (hereinafter referred to as “DM
F ". ) Solution. The impregnation amount is 1300 g / m
² , the surface of the substrate was squeezed to 70% of the thickness of the substrate, excess polyurethane resin was removed, and the concentration was 10%.
The solution was coagulated in a water bath of a DMF solution of% and dried at 140 ° C. (Impregnation step (B))

The obtained substrate is repeatedly dipped and nipped with toluene at 80 ° C., and polyethylene is extracted. At the same time as the extraction, the whole substrate width is deformed by applying a tension of 5 to 10 kg, and then dried. did. The basis weight of the extraction base material was 520 g / m ² , length 220 m, width 1.38 m, and length (Lb) / width (Wb) 159. (Extraction step (C)) The value of formula (I) was 1.20.

Two rolls of a polyurethane DMF solution were applied to the surface of the deformed extraction substrate using a gravure roll of 200 mesh. (Extraction substrate fixing step (D))

After drying, the coated surface was polished with a 320 mesh sandpaper, and further polished with a 600 mesh sandpaper. A suede-like artificial leather with a fine nylon fiber raised on the surface. (Nailing process (E))

The obtained artificial leather was dyed brown using a gold-containing dye. The resulting suede-like artificial leather had good surface sliminess and chalk mark properties, but was of low quality due to visible defects based on the needle holes.

[Comparative Example 2] A nylon 6 chip and a polyethylene chip having a density of 0.915 g / cm ³ were mixed with 5 chips.
The mixture was melt-mixed and spun at a ratio of 0:50, stretched, crimped, and cut to prepare a raw cotton having a cut length of 51 mm. Laminated with card and cross layer, 1 with 3 barb needle
Needle punching was performed at a needle density of 2,000 needles / cm ² to prepare a nonwoven fabric having a basis weight of 560 g / m ² and a thickness of 2.8 mm.
The nonwoven fabric was heated by a dryer at 150 ° C., cooled and nip with a metal roll at 90 ° C., and fixed. The obtained nonwoven fabric had a basis weight of 567 g / m ² , a thickness of 1.90 mm, and a density of 0.
30 g / cm ³ , length 255 m, width 1.54 m, length (La) / width (Wa) 166. (Non-woven fabric process (A))

Next, the nonwoven fabric was impregnated with a polyurethane solution. The polyurethane solution used was a polyurethane having a 100% elongation modulus of 270 kg / cm ² , comprising 15% polyurethane, 7% polyoxyethylene ether,
Dimethylformamide containing a coagulation regulator (hereinafter referred to as “DM
F ". ) Solution. The impregnation amount is 985 g / m ²
The surface of the substrate is squeezed to 80% of the thickness of the substrate to remove excess polyurethane resin, and then the concentration is reduced to 10%.
Was coagulated in a water bath of a DMF solution and dried at 140 ° C.
(Impregnation step (B))

The obtained substrate is repeatedly dipped and nipped with toluene at 80 ° C. to extract polyethylene, deformed by applying a tension of 5 to 10 kg to the entire width of the substrate simultaneously with the extraction, and then dried. did. The basis weight of the extraction base material was 450 g / m ² , length 260 m, width 1.41 m, and length (Lb) / width (Wb) 184. (Extraction step (C)) The value of formula (I) was 1.11.

Two rolls of a polyurethane DMF solution were applied to the surface of the deformed extraction substrate using a gravure roll of 200 mesh. (Extraction substrate fixing step (D))

After drying, the coated surface was polished with a 320 mesh sandpaper, and further polished with a 600 mesh sandpaper. A suede-like artificial leather with a fine ultrafine nylon fiber raised on the surface was obtained. (Nailing process (E))

The resulting artificial leather was dyed black using a gold-containing dye. The resulting suede-like artificial leather had good surface sliminess and chalk mark properties, but was of low quality due to visible defects based on the needle holes.

[Comparative Example 3] A nylon 6 chip and a polyethylene chip having a density of 0.915 g / cm ³ were mixed with 5 chips.
The mixture was melt-mixed and spun at a ratio of 0:50, stretched, crimped, and cut to prepare a raw cotton having a cut length of 51 mm. Laminated with card and cross layer, 1 with 3 barb needle
Needle punching was performed at a needle density of 400 needles / cm ² to prepare a nonwoven fabric having a basis weight of 567 g / m ² and a thickness of 2.8 mm.
The nonwoven fabric was heated by a dryer at 150 ° C., cooled and nip with a metal roll at 90 ° C., and fixed. The obtained nonwoven fabric had a basis weight of 570 g / m ² , a thickness of 1.75 mm, and a length of 30.
m, width 1.52m, length (La) / width (Wa) 19.7
Met. (Non-woven fabric process (A))

Next, the nonwoven fabric was impregnated with a polyurethane solution. The polyurethane solution used was a polyurethane having a 100% elongation modulus of 65 kg / cm ² and dimethylformamide containing 12% of polyurethane, 7% of polyoxyethylene ether, and a coagulation modifier (hereinafter referred to as “DM
F ". ) Solution. The impregnation amount is 920 g / m ²
After squeezing the surface of the substrate to 70% of the thickness of the substrate to remove excess polyurethane resin,
Was coagulated in a water bath of a DMF solution and dried at 140 ° C.
(Impregnation step (B))

The obtained substrate was repeatedly dipped and nipped with toluene at 80 ° C. to extract polyethylene and dried. The basis weight of the extraction base material is 400 g / m ² , the length is 40 m,
The width was 1.05 m, and the length (Lb) / width (Wb) was 38.1. (Extraction step (C)) The value of the formula (I) was 1.93.

Shrinking wrinkles occurred on the surface of the deformed extraction base material. Two rolls of a polyurethane DMF solution were applied to the surface of the extraction substrate using a 200 mesh gravure roll, but the wrinkles did not disappear. (Coating process (D))

After drying, the coated surface was polished with a 320 mesh sandpaper, and further polished with a 180 mesh sandpaper to obtain a suede-like artificial leather. (Nailing process (E))

The obtained artificial leather was sliced in the length direction, a solution of DMF / water in a ratio of 90/10 was applied to the sliced surface, immobilized, and dyed brown using a gold-containing dye. . The resulting suede-like artificial leather did not show any defects based on the needle holes on the surface, but had wrinkles, poor appearance, and inferior quality.

[0068]

As described above, according to the method of the present invention,
In a suede-like artificial leather using ultrafine fibers, the surface of the artificial leather is dense, and it is possible to obtain a suede-like artificial leather full of luxurious feeling without defects such as a needle hole caused by a needle punch. It is possible to develop applications as clothing for children.

Claims (3)

[Claims] (A) to (E): (A) a nonwoven fabric step of forming a nonwoven fabric of a composite fiber which can be ultrafine to 0.2 denier or less; (B) impregnating the nonwoven fabric with a polyurethane solution, An impregnation / solidification step of solidifying to form a base material; (C) an extraction step of extracting one component of the conjugate fiber constituting the nonwoven fabric from the base material to form an extraction base material; and (D) a surface of the extraction base material. An extraction substrate fixing step of applying a polyurethane solution or a polyurethane solvent to the
(E) a method of producing a suede-like artificial leather, which comprises the step of raising the coated surface, wherein the length / width value of the extraction base material obtained in the extraction step is (A) a nonwoven fabric The value of the length / width of the nonwoven fabric obtained in the process is expressed by the following formula (I). [Where La and Wa are the length and width of the nonwoven fabric obtained in the nonwoven fabric step (A), and Lc and Wc are the length and width of the extraction base material obtained in the extraction step (C). . ], And then fix the deformed state in the extraction base solidifying step (D) to produce a suede-like artificial leather. 2. The method for producing a suede-like artificial leather according to claim 1, wherein the deformation is performed in the extraction step (C). 3. The method according to claim 1, wherein the density of the nonwoven fabric obtained in the nonwoven fabric step (A) is in a range satisfying 0.25 to 0.40 g / cm ³ .