JP2003293261A - Non-woven fabric for artificial leather and artificial leather - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-woven fabric for an artificial leather excellent in fixing property of an aqueous elastic polymer or water soluble dyestuff, and reducing an affinity to water after a prescribed period, and the artificial leather. <P>SOLUTION: This non-woven fabric for the artificial leather is obtained by performing a plasma electric discharge treatment on a non-woven fabric constituted with a synthetic fiber having ≤8 μm single fiber thickness, then impregnating with the aqueous elastic polymer and dyeing with the water soluble dyestuff. The artificial leather is obtained by using the non-woven fabric and treated with a surface raising on at least one surface of it. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a non-woven fabric used for artificial leather and artificial leather.

[0002]

2. Description of the Related Art Suede-type artificial leather with a napped surface and silver-coated artificial leather with a coating layer on the surface are widely used for clothing, furniture, shoes and automobile interiors because of their ease of maintenance and uniformity. It is used in a wide range of fields such as timber. These artificial leathers are composed of a nonwoven fabric made of synthetic fibers such as polyester fibers, nylon fibers and acrylic fibers, and an elastic polymer. The elastic polymer is impregnated in order to improve strength and abrasion resistance and to impart a texture, and a polyurethane resin is usually used as the elastic polymer. Conventionally, the majority of methods for applying polyurethane have been wet processing using dimethylformaldehyde as a solvent, coating processing and laminating processing using various organic solvents as solvents. On the other hand, in view of environmental problems and ecology-oriented in recent years, the development of solvent-free products has progressed, and water-based polyurethane resins have come to be used due to technical improvement of water-based polyurethane resins.

By the way, since the synthetic fibers constituting the nonwoven fabric for artificial leather are mainly hydrophobic, they are poor in hydrophilicity, and in the process of processing artificial leather, the impregnating property is poor during the impregnation process of the water-based polyurethane resin, and There is a problem that the artificial leather obtained is inferior in texture and cannot be uniformly impregnated in the thickness direction of the non-woven fabric and adheres only to the surface, resulting in poor texture of the obtained artificial leather.

Further, when a dyeing process is carried out using a water-soluble dye in order to finish a suede type artificial leather, a non-woven fabric composed of synthetic fibers having poor hydrophilicity has a poor fixing property to the fibers. Since it is inferior, there is a problem that the obtained artificial leather does not develop vivid color.

On the other hand, when the actually finished artificial leather is used for clothes and shoe uppers, the artificial leather itself is required to have water repellency so that raindrops do not soak into the product. However, there are contradictory requirements that it is not preferable that the final product itself exhibits strong hydrophilicity.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above problems and is for artificial leather, which has good hydrophilicity immediately after the production of the nonwoven fabric and decreases in hydrophilicity over a certain period of time. It is intended to provide a non-woven fabric and artificial leather.

[0007]

In order to solve the above problems, as a result of intensive studies, the inventors have invented the nonwoven fabric of the present invention. That is, the present invention is achieved by modifying a nonwoven fabric for artificial leather composed of synthetic fibers having a single fiber thickness of 8 μm or less by plasma discharge treatment.

That is, according to the first invention of the present application, a nonwoven fabric composed of synthetic fibers having a single fiber thickness of 8 μm or less is modified by plasma discharge treatment, and then impregnated with a water-based elastic polymer and water-soluble. A non-woven fabric for artificial leather, which is characterized by being subjected to a dyeing treatment using a dye.

A second invention of the present application is the three-dimensional structure according to the first invention, in which a hydroentangling web formed of a slurry of synthetic fibers is laminated with a reinforcing material and a high-pressure columnar water jet is jetted from above the web. Another object of the present invention is to provide a nonwoven fabric for artificial leather, characterized in that fibers and reinforcing material are entangled and integrated.

A third invention of the present application is to provide a nonwoven fabric for artificial leather, characterized in that, in the first invention, the nonwoven fabric is composed of polyester fibers.

Furthermore, a fourth invention of the present application provides a nonwoven fabric for artificial leather, wherein the plasma discharge treatment in the first invention is a corona discharge treatment, and the nonwoven fabric has corona discharge treatment on one or both sides. It is to be.

Further, a fifth invention of the present application is that a nonwoven fabric composed of synthetic fibers each having a single fiber thickness of 8 μm or less is modified by plasma discharge treatment, then impregnated with an aqueous elastic polymer, and water-soluble. It is intended to provide an artificial leather characterized by being subjected to a dyeing treatment using a dye and at least one surface of which has been subjected to a surface raising treatment.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The nonwoven fabric for artificial leather and artificial leather of the present invention will be described in detail below. The nonwoven fabric for artificial leather of the present invention is obtained by subjecting a nonwoven fabric composed of synthetic fibers to plasma discharge treatment. The plasma discharge treatment in the present invention is performed by exposing the nonwoven web to a substance exhibiting a plasma state. The plasma state means that the inert gas is dissociated into the positive and negative charged particles or the inert gas is excited by applying a high voltage to the inert gas or heating it at a high temperature. . As a method for applying a high voltage, it is preferable to employ spark discharge, corona discharge, glow discharge, or the like. In addition, the inert gas used is
A gas that does not polymerize itself under high voltage is used, and specific examples thereof include oxygen, hydrogen, nitrogen, argon, helium, and air. The pressure of the inert gas when applying a high voltage is preferably 0.01 to 20 torr. If it is less than 0.01 torr, reforming is insufficient,
When the pressure exceeds 20 torr, the number of gas molecules is large, so that the plasma intensity apparently increases and the fibrils are cut, which is not preferable.

Among these plasma discharge treatment methods, in order to continuously and stably treat a large amount of non-woven fabric, atmospheric pressure corona discharge treatment is particularly preferable because of simple equipment and treatment process.

In this corona discharge treatment, an appropriate space is provided between the electrode connected to the high voltage generator and the rotating roll, and a high voltage corona is applied to the high voltage corona to generate a high voltage corona. The non-woven fabric is passed through this space at an appropriate speed to react corona-generated ozone or nitric oxide on the non-woven fabric surface to form a carboxyl group, a hydroxyl group,
A hydrophilic group such as a peroxide group is generated, and this hydrophilic group contributes to improvement in hydrophilicity of the nonwoven fabric and durability.

By performing this corona discharge treatment,
Immediately after the treatment, a non-woven fabric with good hydrophilicity can be obtained,
The hydrophilicity deteriorates with the passage of time, and the hydrophilicity is lost after a certain period of time. Further, the fixed time required for the deterioration of hydrophilicity varies depending on the type of the base fiber of the non-woven fabric and the energy amount of the corona discharge treatment.
That is, when the amount of energy is small, hydrophilicity is not expressed, or hydrophilicity is lost in a short time, while
When the amount of energy is large, the hydrophilicity of the obtained nonwoven fabric is maintained for a long time. In the present invention, artificial leather in which high hydrophilicity is exhibited for a certain period of time immediately after the production of the nonwoven fabric to the impregnation of the water-based elastic polymer until the dyeing treatment step is completed, and the hydrophilicity is reduced thereafter, by utilizing this characteristic of corona discharge machining Can be manufactured.

Therefore, the corona discharge treatment energy amount is not particularly limited, but it is particularly preferable that the total energy amount per one surface is 0.05 to 2.0 kW / min.
m ² . The total amount of energy per side is 0.05K
When it is smaller than W min / m ² , the hydrophilicity development ratio is low and the durability is short, as compared with the case where no corona treatment is performed, which is not preferable. On the other hand, if it exceeds 2.0 kW / m ² , the hydrophilicity is not lost for a long period of time, which is not preferable. Since a certain period of time from the production of the non-woven fabric to the impregnation of the water-based elastic polymer and the dyeing treatment step is different in each case, the processing may be performed using an appropriate treatment energy amount in each case.

The present invention relates to the single fiber thickness (fineness) of synthetic fibers.
Is achieved by using ultrafine fibers having a diameter of 8 μm or less. If the fineness is more than 8 μm, when the substrate is subjected to nap treatment, the resulting suede-like surface is greatly inferior in quality such as appearance, touch and texture. More preferably, it is 2 to 6 μm, and if it is finer than 2 μm, the dyeability is deteriorated. On the other hand, if it is more than 6 μm, the dyeability is good, but the suppleness and the tactile feel are poor.

The synthetic fiber used in the present invention is not limited as long as it is a commonly used synthetic fiber, and examples thereof include polyester terephthalate, polybutylene terephthalate, and polyester fibers such as copolymers thereof. Acrylic fibers such as polyacrylonitrile and modacrylic, polyolefin fibers such as polyethylene and polypropylene, polyamide fibers such as nylon 6 and nylon 66, polyvinyl alcohol fibers, polyvinyl chloride fibers, synthetic fibers such as urethane fibers, triacetate fibers, etc. Semi-synthetic fibers, regenerated cellulosic fibers such as cuprammonium rayon, regenerated fibers obtained by spinning a solution of collagen, chitin and the like can be used. Of these fibers, polyester fibers are more preferably used in consideration of the dyeability and durability of the obtained artificial leather.

Further, these fibers have antibacterial properties, heat retaining properties,
It may have a function such as antiallergic property. The cross-sectional shape of the fiber used here is not particularly limited, and not only circular and elliptical but also flat, triangular, Y-shaped, T-shaped, U-shaped,
It may have a so-called atypical cross-sectional shape such as a star shape or a dog bone shape, a hollow shape, a branched shape, or a pulp shape, but from the viewpoint of the tactile sensation after nap treatment, a circular shape, or The oval one is the most preferable.

As a method for producing the nonwoven fabric for artificial leather before the plasma discharge treatment, a conventionally known method is used. That is, using the ultrafine fibers obtained by the direct spinning method, an ultrafine fiber web having a predetermined weight is prepared by a wet papermaking method, and this is laminated with a reinforcing material composed of a woven fabric, a knitted fabric and a long fiber non-woven fabric to form a three-dimensional fabric. Hydro-entanglement treatment to obtain a nonwoven fabric by integration, carding method using splittable conjugate fiber, air laying method, wet papermaking method, etc. to produce a web with a predetermined weight, needle punching or three-dimensional Hydro-entanglement treatment, etc., to split and split the splittable composite fiber by physical impact to develop ultrafine split fibers made of each polymer component to obtain a nonwoven fabric, or to have compatibility Using the sea-island type two-component composite fiber obtained by composite spinning or mixed-spinning of two or more thermoplastic polymers which are not yet used, raw cotton in the state of the sea-island type two-component composite fiber before being ultrafine When Card, a method may be mentioned of obtaining a nonwoven fabric by performing a needle punching or the like. Among these methods for producing non-woven fabrics, in the present invention, from the viewpoint that environmental load and productivity, a product with a uniform texture can be obtained, using a microfiber obtained by direct spinning, a wet papermaking method And a method of obtaining a nonwoven fabric by a three-dimensional hydroentanglement method is more preferable.

Next, the method for producing the nonwoven fabric for artificial leather of the present invention will be described in detail. The wet papermaking method is more suitable for the web before hydroentangling because a product having a uniform texture can be obtained. First, the main synthetic fiber is mixed alone or with other fibers and put into water. If necessary, add a dispersant and a viscous agent, mix with a rotary device such as pulper, disintegrate and homogenize. Dispersion is performed to prepare a fiber suspension having a concentration of about 0.1 to 3%. The suspension is then used
Papermaking is carried out by a paper machine having at least one wire such as long-mesh, short-mesh, and cylinder to obtain a fiber web before entanglement.

Next, the fiber web obtained by the above-mentioned wet papermaking method and the reinforcing material are laminated, but preferably, the reinforcing material is sandwiched between the fiber webs. A laminate of a reinforcing material and a fiber web is placed on a porous support having a substantially smooth surface, the fiber web is placed on top, and a high-pressure water stream is jetted to entangle the fibers together. At this time,
As a porous support to be used, taking a wire as an example, 6
The one equivalent to 0 to 150 mesh is preferable. The liquid used may be any solvent other than the solvent of the fibers to be treated, but water or warm water is usually suitable. Further, the water pressure of the high-pressure water flow is preferably in the range of 4.9 × 10 ^{5 to} 2.5 × 10 ⁷ Pa, and more preferably 4.9 × 10 ^{5 to} 1.2 × 10 ⁷ . The processing speed is preferably 3 to 200 m / min, more preferably 3 to 30 m / min.

In order to make the three-dimensional water flow entanglement stronger, the diameter of the water flow injection hole of the nozzle for injecting the high-pressure water flow is 10 to 500 μm, and the distance between the water flow injection holes of the nozzle is 10 to.
It is preferably 1500 μm. The number of nozzles and the number of three-dimensional hydroentanglement are determined by the basis weight and type of nonwoven fabric, processing speed,
It can be changed as appropriate in consideration of water pressure and the like. Further, the lamination of the fiber web and the reinforcing material and the entanglement integration treatment by high-pressure water jet may be repeated a plurality of times. That is, after performing the lamination of the fiber web and the reinforcing material, it is possible to further laminate the fiber web on the side where the fiber web is laminated first and perform the high-pressure water jet treatment, or turn over the non-woven sheet that is being formed, A high-pressure water jet process may be performed by laminating a fiber web on the opposite side.

It is also possible to further improve the surface quality by rotating the header of the nozzle, oscillating it to the left or right, or oscillating the support wire of the web to the left or right. Further, after the entanglement, it is possible to improve the surface quality by inserting a wire mesh of 40 to 100 mesh between the nozzle and the web, sprinkling the columnar water stream and injecting it into the web.

As a method for producing the artificial leather, a conventionally known method is used. First, the nonwoven fabric for artificial leather obtained by the above method is impregnated with the water-based elastic polymer. As the water-based elastic polymer used for the artificial leather of the present invention, known ones can be used, but it is preferable to use the water-based polyurethane resin from the viewpoint of the texture and the strength of the obtained artificial leather. Further, the content of the water-based elastic polymer is in the range of 1 to 30% by mass, and more preferably in the range of 3 to 20% by mass, based on the total mass of the fibers forming the sheet. The water-based elastic polymer is
Improves the strength and wear resistance of artificial leather, but the content is 3
If it exceeds 0% by mass, a rubbery feel is exhibited and flexibility is greatly impaired, which is not preferable, while the content is 1
If it is less than mass%, the effect is not exhibited, which is not preferable. The method for impregnating the water-based elastic polymer is not particularly limited, but from the viewpoint of the balance of the texture, the nonwoven fabric is directly impregnated with the water-based elastic polymer solution, and if necessary, squeezing with a mangle or a coater for the water-based elastic polymer. It is preferable to use a method of soaking it while coating with.

Further, in order to prevent the water-based elastic polymer to be contained from firmly sticking to the fiber and hardening the texture, a temporary filling material such as polyvinyl alcohol is added to the nonwoven fabric prior to the impregnation treatment of the water-based elastic polymer. Impregnate,
The temporary filling material may be removed after applying the water-based elastic polymer. When a water-soluble substance such as polyvinyl alcohol or carboxymethyl cellulose is used as the temporary filling substance, the non-woven fabric for artificial leather of the present invention has a high impregnating property of these temporary filling substances into the nonwoven fabric, so that a higher effect can be obtained.

The nonwoven fabric sheet thus obtained is dried and then subjected to surface raising treatment, dyeing treatment and the like by a known method to obtain an artificial leather product. Since the length of fluff to be raised affects the appearance such as touch and lighting, it is possible to adjust the desired fluff length by adjusting the surface raising treatment conditions, such as the number and type of sandpaper used for the buff, the shaving speed, and the pressing pressure. Can be obtained.

The order of producing artificial leather from the nonwoven fabric for artificial leather of the present invention is not limited to the above-mentioned order as long as the effect of the present invention is not impaired. For example,
First, the nonwoven fabric may be surface-raised, then impregnated with the water-based elastic polymer, and finally the dyeing treatment step may be performed. First, after the elastic polymer is impregnated, the surface-raised The treatment may be performed, and the dyeing treatment step may be finally performed.

Further, by laminating the surface after dyeing, a silver surface layer is formed on the surface, and a very flexible and soft artificial leather with silver can be obtained. In this silver-coated artificial leather, an easily dyeable polyurethane may be laminated on a base material before dyeing, and then dyed to obtain a dyed silver-containing artificial leather in which the surface color and the base material layer color match.
The artificial leather with dyed silver has an extremely natural texture and appearance when used as casual shoes or sandals.

According to the present invention, a nonwoven fabric composed of synthetic fibers having a single fiber thickness of 8 μm or less is modified by plasma discharge treatment, then impregnated with a water-based elastic polymer and dyeing with a water-soluble dye. The present invention relates to a nonwoven fabric for artificial leather, which is characterized by being subjected to: Further, the present invention relates to artificial leather manufactured using this nonwoven fabric. The nonwoven fabric of the present invention has excellent impregnability with the water-based elastic polymer and the water-soluble dye, so that the water-based elastic polymer and the water-soluble dye can be uniformly impregnated into the nonwoven fabric, and because it has excellent fixability, it is vivid with a good texture. It is possible to obtain artificial leather exhibiting excellent color development. Further, since the hydrophilic property is lost with the passage of time, it is possible to provide a product in which raindrops do not easily penetrate when used as artificial leather for clothing or shoe uppers.

[0032]

The present invention will be described below with reference to examples.
The present invention is not limited to this embodiment. The% used herein is based on the mass of the base material unless otherwise specified. The evaluation methods for various physical properties described in the examples are as follows.

Physical properties in Examples and Comparative Examples were measured by the following methods. 1) <Basis weight> It was measured by the method described in JIS L1096. The unit is g / m ² . 2) <Thickness> Load of 20 g / m according to the method described in JIS L 1096.
Measured at ² . The unit is μm. 3) <Hydrophilicity> The nonwoven fabric sample was set in a direction forming an angle of 45 degrees with respect to the horizontal direction, and then one drop of water was dropped from 10 mm above the sample. The distance until the water droplet penetrates the sample was measured and used as a measure of water absorption. The quicker the penetration, the better the water absorption. The hydrophilicity of the nonwoven fabric sample was measured 2 weeks after the nonwoven fabric was prepared. ◯: Penetration within 20 mm from the dropping position. Δ: Penetration within 50 mm from the dropping position. X: Permeates beyond 50 mm from the dropping position. Or does not penetrate. 4) <PU wettability (wettability of aqueous polyurethane resin aqueous solution)> A solution 50 in which 5% of an aqueous polyurethane resin is dissolved in pure water
A sample cut into a length of 1 cm and a width of 1 cm was gently placed on the liquid surface of ml, and the time required for the sample to completely settle was measured. The PU wettability of the nonwoven fabric sample was measured two weeks after the nonwoven fabric was prepared. ◯: Settles within 5 seconds (good). Δ: Settles in 5 to 20 seconds. X: Sedimentation exceeds 20 seconds. Or does not settle. 5) <Hydrophobicity> The artificial leather sample was set in a direction forming an angle of 45 degrees with respect to the horizontal direction, and then one drop of water was dropped from 10 mm above the sample. The distance at which the water droplet penetrates the sample was measured and used as a measure of hydrophobicity. The more difficult it is to permeate, the better the hydrophobicity. The hydrophilicity of the artificial leather sample was measured 2 weeks after the artificial leather was prepared. ◯: Permeates beyond 50 mm from the dropping position. Or does not penetrate. Δ: Penetration within 50 mm from the dropping position. X: Penetration within 20 mm from the dropping position. 6) <Feeling> After commercializing the artificial leather, the feeling was sensory evaluated by 10 panelists. Those that felt soft and good were rated as ◯, those that felt normal were rated as Δ, and those that felt hard were rated as x. 7) <Surface property> After commercializing artificial leather, sensory evaluation was performed by 10 panelists. When rubbing the surface with your finger, you feel that there is a slimy feeling ○, if you feel a little slimy, △,
The one that I felt was not slimy was marked with x. 8) <Coloring property> After commercialization into artificial leather, sensory evaluation was performed by 10 panelists. When visually evaluated, the one that felt that the color development was vivid was evaluated as O, the one that was felt as normal was evaluated as Δ, and the one that was felt as not vivid was evaluated as X.

Example 1 3.2 μm × 3 mm polyester fiber manufactured by Teijin Limited <TM
04PN SD 0.1 decitex x 3mm> 100
Mass% was disaggregated and dispersed uniformly in water using a pulper to prepare a suspension having a concentration of 1%, and then the suspension was used to obtain a dry basis weight of 55 g / m ^2. Papermaking,
A wet web (W) layer was obtained. Next, a plain weave of 50 g / m ² (weaving density of 60 warps / inch, wefts 50 inches / inch) made from a multifilament yarn of polyethylene terephthalic fiber (the warp and weft fineness is 70 decitex) is used as a reinforcing material. Used as (C), superposed so that the layer structure of the wet web layer and the reinforcing material is W / C / W,
It is loaded on a 76-mesh plain-woven plastic wire and pressure (8.8 × 1) is applied with the three nozzle rows shown below.
Entangling was carried out at an entangling speed of 0 ⁶ Pa) and an entangling speed of 10 m / min.
Further reverse the web, jet the water flow under the same conditions,
Entangled. The nozzle diameter, nozzle spacing, and nozzle arrangement are shown below. The first row has a nozzle diameter of 120 μm and the nozzle spacing of 1.2 mm is arranged in two staggered rows. The second row has a nozzle diameter of 100 μm and the nozzle spacing of 0.6 mm is straight.
Nozzle diameter 100 μm, nozzle spacing 0.6 in the third and third rows
mm is a straight line. Then, after squeezing water with a padder, it was dried at 110 ° C. using an air dryer to obtain a nonwoven fabric. Next, this nonwoven fabric was subjected to corona discharge treatment on both sides of the nonwoven fabric under the condition that the total energy per one surface was 0.8 KW min / m ² , to obtain a nonwoven fabric for artificial leather. Next, the nonwoven fabric for artificial leather was impregnated with a water-based polyurethane liquid while squeezing it using a mangle so that the amount of the aqueous polyurethane liquid was 5% by mass based on the total mass of the nonwoven fabric sheet, followed by drying and curing. Then, the red disperse dye was used to perform a dyeing treatment under the conditions of a dyeing temperature of 130 ° C. and a treatment time of 40 minutes. After drying, the surface was buffed with sandpaper of No. 500 and subjected to a raising treatment to obtain an artificial leather of Example 1 having naps on the surface. The artificial leather was prepared two days after the nonwoven fabric was prepared.

Example 2 Polyester / 6 nylon 20 division type split cotton 2.7 unit decitex × 51 mm fiber manufactured by Unitika Ltd. <N
After passing 91> 100% by mass through a carding machine, it is laminated with a cross wrapper to make a web having a basis weight of 160 g / m ² , which is loaded on a 76-mesh plain weave plastic wire, and the nozzles in three rows shown below. In a row, pressure (6.5 x 1
Entangling was carried out at an entangling speed of 0 ⁶ Pa) and an entangling speed of 10 m / min.
Further reverse the web, jet the water flow under the same conditions,
Entangled. The nozzle diameter, nozzle spacing, and nozzle arrangement are shown below. The first row has a nozzle diameter of 120 μm and the nozzle spacing of 1.2 mm is arranged in two staggered rows. The second row has a nozzle diameter of 100 μm and the nozzle spacing of 0.6 mm is straight.
Nozzle diameter 100 μm, nozzle spacing 0.6 in the third and third rows
mm is a straight line. Then, after squeezing water with a padder, it was dried at 100 ° C. using an air dryer to obtain a nonwoven fabric. As for the single yarn fineness of the split fiber that the splittable conjugate fiber developed by the hydroentangling treatment, the split fiber made of polyester was 3.5 μm, and the split fiber made of 6 nylon was 3.9 μm. This nonwoven fabric was subjected to corona discharge treatment on both sides of the nonwoven fabric under the condition that the total energy per one side was 0.4 kW min / m ² to obtain a nonwoven fabric for artificial leather. The nonwoven fabric was impregnated with a water-based polyurethane liquid while squeezing it using a mangle so that the amount of the aqueous polyurethane solution was 5% by mass based on the total mass of the nonwoven fabric sheet, followed by drying and curing.
Next, a blue disperse dye was used to perform a dyeing treatment under the conditions of a dyeing temperature of 110 ° C. and a treatment time of 50 minutes. After that, the surface was buffed with 400 count sandpaper, and further subjected to a buffing treatment with 180 mesh sandpaper from the reverse side to obtain an artificial leather of Example 2 having naps on the surface. After the non-woven fabric is created, 2
Artificial leather was prepared after a few days of the week.

Example 3 3.2 μm × 3 mm polyester fiber manufactured by Teijin Limited <TM
04PN SD 0.1 decitex 3 mm> 60 mass% and 5.5 μm × 5 mm polyester fiber manufactured by Teijin Ltd.
TM04PN 0.3 decitex x 5 mm> 40 mass%
And disperse and disperse uniformly in water using a pulper to prepare a suspension having a concentration of 1%, and then use the suspension so that the dry basis weight is 70 g / m ^2. Papermaking,
A wet web (W1) layer was obtained. Processing was performed in the same manner as in Example 1 except that the wet web layer (W1) and the reinforcing material (C) were laminated and processed so that the layer structure was W1 / C / W1, and the artificial material of Example 3 was used. I got leather.

Comparative Example 1 An artificial leather of Comparative Example 1 was obtained by processing in the same manner as in Example 1 except that the corona discharge treatment was not performed.

Comparative Example 2 An artificial leather of Comparative Example 2 was obtained by performing the processing in the same manner as in Example 2 except that the corona discharge treatment was not performed.

Comparative Example 3 Tests were carried out except that a polyester fiber <TT04N SD 1.7 decitex × 5 mm> manufactured by Teijin Ltd. having a fiber diameter of 12 μm and a fiber length of 5 mm was used in place of the polyester fiber having a fiber diameter of 3.2 μm and a fiber length of 5 mm. An artificial leather was produced in the same manner as in Example 1.

Comparative Example 4 A non-woven fabric before corona discharge treatment was prepared by the same method as in Example 1, and then a surfactant (water absorption imparting agent for synthetic fibers: Nippo PR-86) manufactured by Nichika Kagaku Co., Ltd. was impregnated so as to be 7% by mass relative to the total mass of the nonwoven fabric sheet, and dried to obtain a nonwoven fabric for artificial leather. Next, in the same manner as in Example 1, the nonwoven fabric for artificial leather was impregnated with a water-based polyurethane liquid while squeezing it using a mangle so that the amount thereof was 5% by mass relative to the total mass of the nonwoven fabric sheet. Immediately after the impregnation treatment, it was good, but as the impregnation treatment progressed, the surfactant in the nonwoven fabric gradually eluted into the water-based polyurethane liquid,
The concentration of water-based polyurethane in the pad solution decreased. As a result, the amount of the water-based polyurethane resin attached to the obtained artificial leather was 2 to 5% by mass, and stable and good artificial leather could not be obtained. Next, the water-based polyurethane resin is 5% by mass.
The adhered sheet was selected and subjected to a dyeing treatment and a raising treatment in the same manner as in Example 1 to obtain an artificial leather of Comparative Example 4.

Table 1 shows the evaluation results of Examples 1 to 3 and Comparative Examples 1 to 4.

[0042]

[Table 1]

As is clear from the comparison between Example 1 and Comparative Example 1 and between Example 2 and Comparative Example 2, the artificial leathers of the present invention all have good texture, surface properties and color developability. I understand. In addition, from the hydrophobicity measurement result measured 2 weeks after the artificial leather is manufactured, the artificial leather of the present invention is
It can be seen that the hydrophilicity is reduced to the same extent as in the comparative example, which is good. From Examples 1 and 2, it can be seen that the artificial leather of Example 1 produced by using the nonwoven fabric obtained by the wet papermaking method and the hydroentanglement method is further excellent in texture. From Comparative Example 3, it is understood that when the single fiber diameter of the main fiber is out of the range of the present invention, the surface property is deteriorated and the slimy feeling which is a characteristic of suede-like artificial leather is impaired. Further, when the hydrophilic property is imparted to the non-woven sheet by using the surfactant (Comparative Example 4), as described above, not only is it difficult to carry out the stable impregnation treatment with the water-based polyurethane resin, but also the coloring property after dyeing is obtained. It can be seen that the surfactant is inferior to the artificial leather of the present invention because the surfactant falls off from the nonwoven sheet during the dyeing treatment.

[0044]

EFFECT OF THE INVENTION The nonwoven fabric for artificial leather of the present invention is excellent in hydrophilicity and water dispersibility by the plasma discharge treatment, and therefore the nonwoven fabric of the water-based elastic polymer and the water-soluble dye is excellent in impregnating property, so that it is fast. Urethane can be impregnated at a processing speed to reduce the processing cost, and since it can be uniformly impregnated and fixed, it provides an artificial leather which has a good texture and is excellent in coloring after dyeing. be able to.
Further, since the hydrophilic property is lost with the passage of time, it is possible to provide a product in which raindrops do not easily penetrate when used as artificial leather for clothing or shoe uppers.

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Claims (5)

[Claims] 1. A non-woven fabric composed of synthetic fibers having a single fiber thickness of 8 μm or less is modified by plasma discharge treatment, then impregnated with an aqueous elastic polymer and dyed with a water-soluble dye. A non-woven fabric for artificial leather, which has been characterized. 2. A hydroentanglement web formed by a wet papermaking method is laminated with a reinforcing material, and a high-pressure columnar water stream is jetted from above the web to three-dimensionally entangle and integrate the fiber and the reinforcing material. The nonwoven fabric for artificial leather according to claim 1, characterized in that 3. The nonwoven fabric for artificial leather according to claim 1, which is a nonwoven fabric composed of polyester fibers. 4. The nonwoven fabric for artificial leather according to claim 1, wherein the plasma discharge treatment is a corona discharge treatment, and the nonwoven fabric has corona discharge treatment on one side or both sides. 5. A non-woven fabric composed of synthetic fibers each having a single fiber thickness of 8 μm or less is modified by plasma discharge treatment, and then impregnated with an aqueous elastic polymer, dyeing treatment with a water-soluble dye, and at least Artificial leather characterized by being brushed on one side.