JPH10168764A - Suedelike artificial leather having pearly luster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pearly sueded artificial leather, having the surface covered with naps of ultrafine fibers and having a sueded touch and appearance and a pearly luster feeling such as a starry sky abounding with stars twinkling in a night sky of a fine weather and to provide a method for producing the sueded artificial leather. SOLUTION: This sueded artificial leather having a pearly luster is obtained by fixing a pearly pigment in the form of spots on the surface of a napped layer with a binder resin and regulating the shortest distance between respective spots and the adjacent spots to 50-500μm in the dyed sueded artificial leather comprising the napped layer composed of ultrafine fibers of <=0.5 denier size on the surface of a substrate composed of a textile fabric and an elastic polymer impregnated thereinto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suede-like artificial leather having a pearl-like luster, a suede-like fluffiness and a lighting effect, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, various artificial suede-like leathers having napped fine fibers on the surface have been proposed. For example, Japanese Patent Publication No. Hei 6-37752 discloses a soft suede-like artificial leather whose surface is covered with nap of ultrafine fibers. As a method for changing the appearance of a suede-like raised hair surface, Japanese Patent Publication No. 33577/1994 discloses a method in which the raised hair surface has a fold or a texture.
JP-A-45717 proposes a method of dyeing the surface of an extremely fine nap by a printing method, however, a method which achieves both nap and pearl tone has not been proposed yet.

[0003] Among pearl-like artificial leathers, various leathers having a surface with a silver surface layer or having a foamed structure have been proposed in the past, for example, Japanese Patent Publication No. 57-2538.
Japanese Patent Publication No. JP-A-58-45504 discloses that a polyurethane layer containing a pearl pigment and a clear layer of polyurethane are laminated on the surface of a fiber substrate. A layer in which a concealing layer (A), a pearl coloring layer (B) and a matting layer (C) are sequentially laminated, and JP-A-6-264370 discloses a nubuck type artificial leather made of foamed polyurethane having a metallic powder. Has been proposed respectively.

As described above, various artificial leathers having a pearly luster have been studied in the past, but all of them are related to artificial leather with a grain surface layer, and have a pearly luster and a suede-like raised hair. Suede-like artificial leather that balances the feeling has not yet been proposed. In recent years, from the diversity of tastes,
There is a strong demand for suede-like artificial leather that has both pearly luster and suede-like raised hair. However, when a pearl pigment is applied to the surface of the nap to develop a pearly feeling, the nap of the surface is damaged or the applied pearl pigment easily falls off, and the pearly luster and suede tone are obtained. It has been considered that it is almost impossible to achieve both of the napped feeling from the conventional common sense.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a suede-like feel and a pearl-like luster like a starry sky that shines in looks and a clear night sky, the surface of which is covered with extra-fine fiber nap. An object of the present invention is to provide a pearl-like suede-like artificial leather and a method for producing the same.

[0006]

According to the present invention, there is provided a fibrous cloth and a raised layer made of ultrafine fibers of 0.5 denier or less formed on the surface of a base made of an elastic polymer impregnated therein. In a dyed suede-like artificial leather, a pearl pigment is fixed in the form of spots on a surface of the napped layer by a binder resin, and the shortest distance between each spot and an adjacent spot is 50 to 5 mm.
It is a pearl-like suede-like artificial leather characterized by having a thickness of 00 μm.

The pearl-like suede-like artificial leather of the present invention comprises:
Prior to or after dyeing a suede-like artificial leather in which a raised layer made of ultrafine fibers of 0.5 denier or less is formed on the surface of a base made of a fiber cloth and an elastic polymer impregnated therein, The binder resin solution containing a pearl pigment is applied to the surface in the form of a spot, and dried, or more preferably, a method of performing a stone wash treatment after drying.

[0008] The thickness of the ultrafine fibers forming the nap layer is 0.5 denier or less, preferably 0.01 denier to 0.0001 denier. If the thickness of the nap fiber exceeds 0.5 denier, it is necessary to increase the nap length in order to obtain the effect of the nap, and the spot-like pearl pigment to be applied later is buried in the nap. Pearl effect is reduced. 0.00
If the denier is less than 01 denier, the effect of the suede tone of the leather is improved, but even if the fiber is too thin, only a light color is obtained due to irregular reflection of light, which is not preferable.

[0009] The method for producing ultrafine fibers constituting a suede-like artificial leather having a raised layer having a surface of 0.5 denier or less according to the present invention comprises mixing two or more polymers having different solubility or degradability. A method of extracting or decomposing and removing a part (for example, a sea component) of ultrafine fiber-generating fibers obtained by a spinning method such as a spinning method, a sea-island composite spinning method, or a split-type composite spinning method; A method of forming ultrafine fibers by decomposing and removing a part of the fibers (for example, sea component) of the nap portion after forming the structure, or blowing out the fibers with a high-speed gas immediately after discharging the fiber-forming polymer from the melt spinning nozzle to thin the fibers. A known method for producing ultrafine fibers, such as a melt blow method, can be used, but from the viewpoint of controlling the fiber thickness and the stability of the ultrafine fibers, a method of passing through ultrafine fiber-generating fibers is preferred. Examples of the resin constituting the ultrafine fibers include known polyesters including aromatic rings such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon-6, nylon-66 and nylon-610, and polyolefins such as polyethylene and polypropylene. Polymers selected from resins are exemplified.

Examples of the resin component constituting the ultrafine fiber-generating fiber which are extracted or decomposed and removed include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polystyrene and styrene-acryl. At least one polymer selected from polymers such as a system monomer copolymer and a styrene-ethylene copolymer is exemplified.

Next, as a method for forming a suede-like sheet using the above-mentioned ultrafine fibers or ultrafine fiber-generating fibers, there are known methods, for example, a step of producing an entangled nonwoven fabric comprising the ultrafine fiber-generating fibers, By sequentially impregnating and coagulating the nonwoven fabric with the elastic polymer solution, modifying the ultrafine fiber-generating fibers into ultrafine fibers, forming the nap on at least one surface, and dyeing the obtained fiber nap substrate. Can be achieved. That is, as a method for producing an entangled nonwoven fabric of microfiber-generating fibers, a conventionally known method is used to perform processing such as stretching, heat setting, crimping, cutting, and defibrating to produce raw cotton, Is defibrated with a card and formed into a random web or a cross-wrap web with a weber. The obtained webs are laminated as necessary to obtain a desired weight. The weight of the web varies depending on the application, but generally it is desirable to be in the range of 100 to 3000 g / m ² . Next, the fiber is entangled using known means to form a fiber-entangled nonwoven fabric. Preferred entanglement methods are a needle punching method and a high-pressure water jet method. The number of needle punching and the conditions for needle punching vary depending on the shape of the needle used and the thickness of the web, but are generally 200 to 2500 punches / hour.
It is preferable to set within the range of cm ² in order to obtain a suede-like artificial leather having a pearly feeling.

Next, the fiber entangled nonwoven fabric is impregnated with an elastic polymer,
Solidifies. As the elastic polymer impregnated in the fiber-entangled nonwoven fabric, a known polymer elastic material can be used, but it is preferable to use a polyurethane resin from the viewpoint of a feeling. As a preferred polyurethane resin, as a soft segment,
A polyester diol obtained by reacting a diol with a dicarboxylic acid or an ester-forming derivative thereof, a polyester diol, a polylactone diol, a polycarbonate diol, at least one kind having a number average molecular weight of 500 to 5,000 selected from the group consisting of polyether diol and the like. There is a so-called segmented polyurethane obtained by using a polymer diol and reacting it with a diisocyanate compound and a low molecular chain extender.

The diol compound constituting the soft segment is preferably a compound having 6 to 10 carbon atoms in terms of durability or leather-like texture.
-Methyl-1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,8-octanediol,
Examples thereof include 1,9-nonanediol and 1,10-decanediol. Representative examples of dicarboxylic acids include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid and sebacic acid, and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid.

The number average molecular weight of the polymer diol is 500
If it is less than 10%, it is not preferable because it lacks flexibility and a natural leather-like texture cannot be obtained. When the number average molecular weight of the polymer diol exceeds 5,000, the urethane group concentration decreases, so that it is difficult to obtain a sheet having a balance in flexibility, durability, heat resistance, and hydrolysis resistance. Examples of the low molecular chain extender include low molecular compounds having two active hydrogen atoms, such as ethylene glycol, propylene glycol, butanediol, hexanediol, and ethylenediamine. Examples of the diisocyanate compound include aromatic, aliphatic, and alicyclic compounds such as 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, and xylylene diisocyanate. If necessary, a pigment, a dye, a coagulation regulator, a stabilizer and the like may be added, and two or more kinds of polymers may be used in combination.

The method of applying the polymer elastic body is not particularly limited, but a method of impregnating the fiber entangled nonwoven fabric with the solution of the elastic polymer is preferable from the viewpoint of the balance of the feeling. Further, from the viewpoint of a natural leather-like soft texture, the weight ratio of the fibers constituting the woven or nonwoven fabric of the base layer to the elastic polymer is preferably in the range of 30/70 to 80/20.
More preferably, the weight ratio of fiber / elastic body is 40/6.
It is in the range of 0-55 / 45. If the ratio of the fibers in the base layer is too low, a rubber-like texture is unfavorable, and if the ratio of the fibers is too high, the texture becomes paper-like and the desired natural leather-like texture cannot be obtained.

The fiber substrate obtained by impregnating and coagulating the elastic polymer acts as a non-solvent for the island component of the elastic polymer and the ultrafine fiber-generating fiber, and as a solvent or a decomposer for the sea component. By processing with a liquid, the ultrafine fiber-generating fibers are modified into ultrafine fiber bundles to obtain a fibrous base comprising an ultrafine fiber entangled nonwoven fabric and an elastic polymer. Needless to say, a method of modifying the ultrafine fiber-generating fibers into ultrafine fiber bundles before impregnating and coagulating the elastic polymer can also be used. Next, at least one surface of the fibrous substrate is provided with a raised surface of ultrafine fibers. As a method for forming the fiber nap, a well-known method such as buffing with sandpaper or brushing of a needle cloth may be used.

Then, the obtained fiber substrate is dyed to obtain a suede-like artificial leather. However, in order to achieve both the pearl-like luster and the suede feeling, which are the characteristics of the present invention, each spot is dyed before or after dyeing. A method is used in which a binder resin solution containing a pearl pigment is applied in the form of a spot such that the shortest distance between the spot and an adjacent spot is 50 to 500 μm, followed by drying.

Examples of the pearl pigment used include those obtained by coating mica with titanium oxide and fine metal powders. Among them, pearl pigments having a particle diameter of 1 μm to 70 μm obtained by coating mica with titanium oxide are used. And multi-layer reflection between layers, and as a result, deep and high-grade gloss can be obtained by light interference, which is preferable. The amount of the pearl pigment is preferably from 10% by weight to 300% by weight based on the binder resin. When the amount of the pearl pigment used is less than 10% by weight, the pearly feeling is low and the commercial value is low. When the amount exceeds 300% by weight, the pearl pigment has poor fixation and detaches the pearl pigment during wearing. This causes a problem in durability.

The role of the binder resin is to fix the pearl pigment in a spot-like manner, and a known polymer of an elastic polymer or an inelastic polymer can be used.
As an example, polyurethane resin, polyacrylic resin,
Polyamide resin, polyester resin, polyvinyl chloride resin and the like can be mentioned, but an elastic polymer is preferable, and among them, a polyurethane resin is preferable in terms of texture. The binder resin liquid may be a solution or a dispersion of the binder resin, and the binder resin concentration in the binder resin liquid is preferably 1 to 40% by weight. Any solvent or dispersion medium for the binder resin liquid can be used as long as it is a liquid capable of dissolving or dispersing the binder resin.

Next, the solution containing the pearl pigment is obtained by first preparing a binder resin solution or an aqueous dispersion, and dispersing a desired amount of the pearl pigment in the solution. In order to enhance the stability of the dispersibility of the pearl pigment, a thickener may be added as necessary. This binder resin solution containing the pearl pigment is applied to the raised surface in a spot manner, and the method may be spraying, gravure printing, textile printing, or applying a known method such as an inkjet method. The gravure printing method is most preferable as the method for easily applying the coating. In order to achieve both the suede feeling and the pearly feeling, which are features of the present invention, it is necessary to maintain the shortest distance between a spot and an adjacent spot at 50 to 500 μm. When the shortest distance is less than 50 μm, a suede feeling is lost and a pearly feeling is generated on the entire surface, resulting in a tone with silver.
On the other hand, if it exceeds 500 μm, the suede feeling increases and the pearl feeling decreases. In the present invention, all of the spots have a minimum distance of 50 to 50 between adjacent spots.
It is not necessary to maintain 0 μm, and if it is a part, the distance may be outside the shortest distance condition defined in the present invention. The size of each spot is 250 μm ²
０．２0.25 mm ² is desirable.

After the pearl pigment-containing binder resin solution is applied, drying is performed to fix the pearl pigment. If the subsequent coating step is before dyeing, the dyeing treatment is performed to obtain the pearl-like suede-like artificial leather of the present invention. In order to cause the pearl pigment to shine, it is important that the background is colored deeply by dyeing. In other words, in order to exhibit a pearly luster like a starry sky shining in a clear night sky, it is preferable that the artificial leather has a sufficiently deep dark color tone like a clear night sky. Of course, if the artificial leather has been dyed prior to the application of the pearl pigment, it is not necessary to dye again, but if desired, it may be dyed again to exhibit a more vivid gloss. After the pearl pigment is fixed, a pebble-like pumice, water and a sample (artificial leather) are put in a rotary washer and subjected to a stone washer treatment to wash the pearl pigment. The unclear boundary becomes unclear, giving a natural feeling, and a pearl-like suede artificial leather with a more natural leather tone can be obtained. Regarding the equipment and conditions used for this stone washer, use the same equipment as that usually used for jeans products and fabrics, under milder conditions than in the case of jeans, and without using a decolorizing agent. Will be In this treatment, it is preferable that the artificial leather is cut to a length of about 1 to 30 m and then treated.

[0022]

EXAMPLES Next, the embodiments of the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Parts and percentages in the examples relate to weight unless otherwise specified.

Example 1 Nylon-6 / polyethylene was used as a chip in a 50/5 ratio.
After mixing at a weight ratio of 0, the mixture is spun with an extruder to spin sea-island fibers (nylon-6 is an island component, and polyethylene is a sea component), and is drawn and cut to obtain 4 denier, 51 mm long short fibers. It was prepared, cross-wrapped with a weber, and subjected to needle punching at 1500 punches / cm ² using a needle punching machine to obtain an entangled nonwoven fabric. This fibrous sheet is impregnated with a dimethylformamide solution of polyurethane (polyurethane composed of poly 3-methyl-1,5-pentane adipate and polyethylene glycol having an average molecular weight of 2000, polyurethane composed of 4,4'-diphenylmethane diisocyanate and butanediol). After wet coagulation, the sea component of the fiber component was extracted with a solvent to obtain a base layer having a basis weight of 270 g / m ² , a thickness of 0.8 mm, and a polyurethane / fiber ratio of 55/45. The fineness of the nylon ultrafine fibers in the obtained sheet was 0.006 denier and had a soft leather-like texture. One surface of the obtained substrate layer was buffed with sandpaper to obtain a substrate having a raised surface made of the nylon ultrafine fibers. Next, staining was performed under the following conditions.

Dyeing conditions Lanyl Brown GR (manufactured by Sumitomo Chemical) 4% (owf) Dyeing aid 1 g / l Dyeing temperature 90 ° C. After drying, rubbing and hair styling give excellent appearance and excellent mechanical properties. A brown suede-like artificial leather was obtained.
Using a gravure printing machine, a polyurethane resin solution containing a pearl pigment was printed on the surface of this artificial leather under the following conditions using a gravure printing machine.

Polyurethane Resin Solution Composition Polycarbonate Polyurethane 4% Iriodin 100 Silver Pearl (Pearl Pigment) 4% (Merck Japan Ltd., Particle Size 10-60 μm) Solvent (Dimethylformamide) 92% Gravure Printing Roll Specifications Cell Shape Grid Line Number 200 lines / 1 inch Cell depth 36μ

After the pearl pigment-containing polyurethane solution is printed, dried and fixed, and then lightly brushed, a brown pearly gloss having a pearly luster is spotted in the appearance having a suede-like surface feeling. Pearl-like suede-like artificial leather was obtained. This product was photographed with a scanning electron microscope, and the shortest distance between the spot adjacent to the pearl pigment spot and measured was 80 μm. This product had a very luxurious feeling, with the pearl pigment vividly shining on the suede surface dyed in a deep color.

Example 2 Before dyeing a polyurethane solution containing a pearl pigment in the same manner as in Example 1, the same pearl pigment-containing binder solution as in Example 1 was applied to the napped substrate whose surface was buffed in Example 1 above. After gravure printing, when dyed in the same manner as in Example 1, a luxurious brown pearl-like suede-like artificial leather with a pearl-like glossy spot in the appearance with a suede-like surface feeling was gotten.

Example 3 The brown pearl-like suede-like artificial leather obtained in Example 1 was stone-washed under the following conditions. Stone wash processing conditions Washing machine Rotary washing machine Water volume 200L Water temperature 40 ° C Pumice stone volume 60kg Activator 1kg Pearl-like suede-like artificial leather 5kg Processing time 40 minutes Was trimmed. The obtained artificial leather had a natural brown pearl color tone in which the boundary between the spot portion and the napped portion was blurred.

Comparative Examples 1 and 2 A screen having the shortest distance between the following openings and the following openings was prepared on the suede-like artificial leather produced in Example 1 using a screen printing machine. Then, the same pearl pigment-containing polyurethane solution as used in Example 1 was applied to produce a pearl-like artificial leather. Screen type Comparative Example 1 Comparative Example 2 Shape of opening portion Circular dot Circular dot Shortest distance of opening portion 20 μm 1000 μm Size of opening portion (diameter) 150 μm 150 μm The one produced in Comparative Example 1 has no napped feeling, It became a pearl-like artificial leather with a pearly feel, far from suede-like ones. In Comparative Example 2, the suede feeling was retained, but the pearly feeling was small, and artificial suede-like artificial leather was obtained. Table 1 shows the results of the above examples and leather examples.

[0030]

[Table 1]

[0031]

According to the present invention, the surface is covered with nap of fine fibers, and has a suede-like feel and a pearl-like luster like a starry sky that shines in looks and a clear night sky. Excellent design that could not be used for clothing,
A pearl-like suede-like artificial leather suitable for shoes, bags, sports gloves and the like can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Hosokai 3-8-2 Nihombashi, Chuo-ku, Tokyo Kuraray Co., Ltd. (72) Inventor Kazushi Koyama 3-82-2 Nihonbashi, Chuo-ku, Tokyo Co., Ltd. In Kuraray

Claims (3)

[Claims] 1. A suede-like artificial leather in which a raised layer made of ultrafine fibers of 0.5 denier or less is formed and dyed on the surface of a base made of a fibrous fabric and an elastic polymer impregnated therein. Wherein the pearl pigment is fixed in the form of spots on a surface of the napped layer with a binder resin, and the shortest distance between each spot and an adjacent spot is 50 to 500 μm. leather. 2. Prior to dyeing a suede-like artificial leather in which a raised layer made of ultrafine fibers of 0.5 denier or less is formed on the surface of a base made of a fiber fabric and an elastic polymer impregnated therein. Alternatively, after dyeing, a method for producing a suede-like artificial leather, comprising applying a binder resin solution containing a pearl pigment to the surface of the naps in a spot form and drying. 3. The production method according to claim 2, wherein a binder resin solution containing a pearl pigment is applied in a spot form on the piloerection surface, dried and then subjected to a stone wash treatment.