JPH08246357A - Suede-like artificial leather and method for producing the same - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a suede-like artificial leather which is soft and has appropriate elasticity, and in which surface-dyed naps and undyed naps are mixed. [Structure] In a leather-like napped sheet mainly composed of ultrafine fibers and a polyurethane polymer, the inner layer portion is not substantially dyed, and the surface is a mixture of dyed naps and non-dyed naps. .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is characterized by a mixture of dyed naps and non-dyed naps, and is flexible and has appropriate elasticity, and is a fiber napped sheet having excellent morphological stability. It is related to goods and is suitable for uses such as shoes and bags.

[0002]

2. Description of the Related Art Conventionally, many dyed napped sheet materials have been proposed. Among them, napped sheet materials made of ultrafine fibers and an elastic polymer have a moist feel and are excellent in color developability, appearance and texture. Therefore, it is used for various purposes. In particular, a sheet-like material having short hairs, uniform naps, and uniformly dyed is elegant and has a high-class feeling, and is widely used for clothes, ornaments and the like. On the other hand, the demand for diversification of sensitivities of products has been increasing year by year, and a napped sheet material having an unprecedented appearance, softness and excellent shape stability has also been demanded. Among them, there has been a long-standing need for a napped sheet-like material with a feeling of fluffiness, in which different color tones are mixed, but recently, animal hair-finished napped sheets in which dyed napped and undyed napped are mixed are strongly requested. Has been done.

In order to meet the demand for a fluffy sheet material having a feeling of fluffiness, for example, Japanese Patent Laid-Open No. 6-136671 discloses a method for dyeing a napped sheet material composed of an ultrafine fiber and an elastic polymer having different metric brightness. It is disclosed. Also,
Japanese Patent Publication No. 48-11925 describes a method of obtaining a mottled appearance by blending undyed fiber and undyed fiber, needle punching, nap treatment, and dyeing.

[0004]

However, in these methods, napping treatment is performed after mixing fibers having different lightness, or napping treatment is performed after forming a sheet from fibers having different lightness and an elastic polymer. Although the naps were made uniform and a feeling of shimofuri was obtained in which different color tones were subtly mixed, the target fiber napped sheet in which dyed naps and non-dyed naps were mixed was not obtained.
Further, in the conventional method, since the dyeing is carried out after napping, the darker the surface, the more uniform the color tone is. An object of the present invention is to provide a fiber napped sheet-like material which is soft and has appropriate elasticity, and in which dyed naps and non-dyed naps are mixed.

[0005]

The present invention is a leather-like napped sheet mainly composed of ultrafine fibers having an average fineness of 0.1 dr or less and a polyurethane polymer, and the inner layer portion is not substantially dyed. The surface relates to a suede-like artificial leather characterized in that dyed naps and non-dyed naps are mixed.

The suede-like artificial leather of the present invention is, for example,
The following steps can be combined. That is,
A step of producing ultrafine fiber-generating fibers (for example, sea-island cross-section fibers) that can be transformed into an ultrafine fiber bundle, a step of producing an entangled nonwoven fabric made of the fibers, a step of temporarily fixing the nonwoven fabric as necessary, the entangled nonwoven fabric A step of impregnating with an elastic polymer liquid and wet coagulating, a step of converting the fibers into an ultrafine fiber bundle, a step of forming naps on at least one surface, and a fiber napped suture obtained
The suede-like artificial leather of the present invention can be manufactured by the step of dyeing the cord and the step of scraping a part of the substantially non-dyed fiber inside the sheet to the surface.

The polymer constituting the island component of the ultrafine fiber-generating fiber of the present invention is, for example, nylon 6 or nylon 6
6, nylons typified by 6, nylon 610 and nylon 12, other spinnable polyamides, polyethylene terephthalate or a copolymer containing them as a main component, polybutylene terephthalate or a copolymer containing them as a main component, aliphatic It is at least one polymer selected from spinnable polyesters such as polyesters or copolymers thereof, melt-spinnable polymers such as polyolefins such as polyethylene, polypropylene and polybutylene. In addition, the polymer that constitutes the sea component is a polymer that has different solubility or degradability in the solvent or decomposing agent from the island component and has a low affinity with the island component, and the polymer of the island component under spinning conditions. It is a polymer having a melt viscosity smaller than the melt viscosity or a small surface tension, and examples thereof include polyethylene, polypropylene, polystyrene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, styrene-ethylene copolymer, and styrene-acryl copolymer. It is at least one polymer selected from polymers such as polymers.

The ratio of the ultrafine fiber component in the ultrafine fiber generating fiber is preferably 40 to 80% by weight from the viewpoint of spinning stability and economy. The ultrafine fiber-generating fiber is made into a fiber having a fineness of 2 to 10 denier through processing steps such as drawing, crimping, heat setting, cutting, and opening by a conventionally known method.

The single fiber fineness of the ultrafine fibers constituting the ultrafine fiber generating fiber is preferably 0.1 denier or less. When the single fiber fineness exceeds 0.1 denier, the fibers are too thick and a soft texture cannot be obtained. However, it is possible to mix regular fibers within a range that does not impair the texture, and it is also possible to mix ultrafine fiber-generating fibers having different average fineness of the ultrafine fibers.

The ultrafine fiber-generating fiber is defibrated with a card,
Random or cross-wrap webs are formed through webbers and the resulting fibrous webs are laminated to the desired weight and thickness. Then, needle entanglement or hydroentanglement treatment is performed by a known method to obtain an entangled nonwoven fabric. At this time, the different fibers described above may be mixed. The number and conditions of needle punches differ depending on the shape of the needle used and the thickness of the web, but are generally set within the range of 200 to 2500 punches / cm ↑ 2. If the needle punching conditions are too strong, the fiber cutting will increase rather than the fiber entanglement effect, resulting in deterioration of physical properties such as tear strength. Also,
If the needle punching conditions are too weak, the physical properties such as peel strength are deteriorated, and the napped fibers are insufficient, resulting in poor appearance.

Next, the fiber entangled nonwoven fabric is impregnated with an elastic polymer,
Solidify. The elastic polymer impregnated in the fiber entangled nonwoven fabric is, for example, polyester diol having an average molecular weight of 500 to 3000,
At least one type of polymer diol selected from polyether diol, polycarbonate diol, etc.,
Selected from aromatic, alicyclic, and aliphatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, isophorodiisocyanate, and hexamethylene diisocyanate. Further, it is a polyurethane obtained by reacting at least one kind of diisocyanate and at least one kind of low molecular weight compound having two or more active hydrogen atoms at a predetermined molar ratio. Polyurethane is used as a polymer composition to which a polymer such as synthetic rubber or polyester elastomer is added, if necessary.

Next, a fiber-entangled nonwoven fabric is impregnated with a polymer liquid obtained by dispersing a polymer mainly composed of polyurethane in a solvent or a dispersant, treated with a non-solvent for the polymer, and wet-coagulated to obtain a fiber material. Use as a base. Additives such as colorants, coagulation regulators, antioxidants, etc. are added to the polymer liquid as needed.
The amount of polyurethane or polyurethane composition in the fibrous substrate is preferably in the range of 30 to 60% by weight as solid content. If the amount is out of this range, the balance between the fiber and the elastic polymer is deteriorated, and the product loses its stiffness and the swelling feeling cannot be obtained.

The polymer-impregnated and solidified fibrous substrate is a non-solvent for the ultrafine fibers and the polymer, and is treated with a solvent or a decomposing agent for the sea component of the ultrafine fiber-forming fibers to produce the ultrafine fiber-forming type. The fibers are made into ultrafine fiber bundles.

Next, at least one surface of this substrate is raised so as to form a napped surface mainly composed of ultrafine fibers.
A known method such as buffing with a sand paper or the like is used as the method for forming the raised fiber surface.

Next, the obtained fibrous sheet is dyed, and dyeing only the surface is an essential requirement in the present invention. Generally, if the inside of the sheet is not dyed, the cutting edge looks whitish, so it is a conventional dyeing method to try to dye the inside of the sheet, for example, in Japanese Examined Patent Publication No. 6-74548, the surface of the sheet. A staining method in which the staining gradient from the inside to the inside is small is disclosed. However, in the present invention, since substantially undyed fibers inside the sheet are scraped to the surface after dyeing, it is necessary to dye only the sheet surface.

As a method for dyeing only the surface of the sheet,
When the fibers constituting the sheet are polyamide or cationic dyeable polyester, dyeing by padding, a method of gravure-coating a dyeing solution and then steaming and fixing, and printing are mentioned. When the fibers constituting the sheet are difficult to be dyed at normal temperature and pressure, such as polyester and polyolefin, a method of applying a dyeing solution by gravure and then steaming and fixing, a method such as printing may be used.

For example, when the fibers constituting the sheet are polyamide and substantially only the surface is dyed by padding, dyes mainly composed of acid dyes, metal complex dyes, etc. are used, but darkening, From the viewpoint of fastness, it is preferable to use a metal complex salt dye. The dye bath temperature is 70 ° C. or higher, preferably 80 ° C. or higher. If it is less than 70 ° C, a dyeing product having good levelness can be obtained, but it does not meet the purpose of the present invention, and a large amount of dye is dyed inside the sheet to impair the texture of the sheet, resulting in poor fastness. Cold dyeing is not preferred. The dyeing time is 10 seconds or less, preferably 3 to 5 seconds. If the dyeing time is long, a large amount of dye is dyed on the surface, the texture of the sheet and the touch of the surface are impaired, and if the dyeing time is short, the desired color developability may not be obtained.
The dyed fibrous sheet can be subjected to finishing treatment such as chaffing and softening treatment.

Next, the substantially non-dyed fibers inside the sheet are scraped to the surface, and it is preferable to use a cloth raising machine. The shape, angle, number of times of raising, etc. of the clothing are adjusted according to the desired appearance. At this time, it is also possible to raise hair in a pattern to form raised hair. The raised napped sheet is subjected to finishing treatments such as light resistance treatment and rubbing treatment as necessary to obtain a fiber napped sheet-like product.

The fiber napped sheet-like material of the present invention is a fiber napped sheet-like material in which the napped dyed and the non-dyed napped are irregularly mixed, having flexibility and moderate elasticity.

[0020]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The parts and% in the examples relate to weight unless otherwise specified.

Example 1 10-denier mixed spun fiber consisting of 50 parts of 6-nylon (island component) and 50 parts of polyethylene (sea component)
It was stretched 5 times, crimped, and cut into a fiber length of 51 mm to obtain staples. The cross section of this fiber was observed with an electron microscope, and the average fineness of the ultrafine fiber (calculated by dividing the total cross-sectional area of the island components by the number of islands) was about 0.01 denier. The web is then made with a cross-wrap webber, alternating from both sides of the web for a total of 400 punches /
cm ↑ 2 needle punching, and weight of about 600
A fiber-entangled non-woven fabric having a g / m of ↑ 2 was prepared. This non-woven fabric was impregnated with a 13% dimethylformamide solution of polyester-based polyurethane elastomer, coagulated and washed with water, and then polyethylene was dissolved and removed in toluene to give a thickness of 1.
A 3 mm sheet-shaped substrate was obtained. This base material is # 180 and #
It was buffed with 240 sandpaper, put into the following dyeing bath maintained at a temperature of 80 ° C. for 3 seconds, and dried. (Dyeing bath) Dye: Irgallan Yellow GRL (Ciba Geigy) 2
5 g / l Kayaka Langley BL (Nippon Kayaku Co., Ltd.) 15 g / l Then, the dyed material thus obtained was passed through a needle cloth raising machine three times to scrape substantially undyed fibers inside the sheet to the surface. The obtained fiber napped sheet-like material had a mixture of naps dyed on the surface and naps that were not substantially dyed, and had an animal hair-like texture with an excellent texture.

Example 2 A 10-denier 6-nylon raw yarn and a 14-denier mixed spun fiber consisting of 50 parts of 6-nylon (island component) and 50 parts of polyethylene (sea component) were combined to give 2.9 times. It was stretched, crimped and cut into a fiber length of 51 mm to obtain staples. The cross section of the mixed spun fiber was observed with an electron microscope, and the average fineness of the ultrafine fiber was calculated to be about 0.015 denier. The web is then made with a cross-wrap webber, alternating from both sides of the web for a total of 400 punches /
cm ↑ 2 needle punching, and basis weight is about 350
A fiber-entangled non-woven fabric having a g / m of ↑ 2 was prepared. This non-woven fabric was impregnated with a 13% dimethylformamide solution of polyester-based polyurethane elastomer, coagulated and washed with water, and then polyethylene was dissolved and removed in toluene to give a thickness of 1.
A 5 mm sheet-shaped substrate was obtained. This base material is # 180 and #
It was buffed with 240 sandpaper, put into the following dyeing bath maintained at a temperature of 80 ° C. for 3 seconds, and dried. (Dyeing bath) Dye: Irgallan Yellow GRL (Ciba Geigy) 2
5 g / l Kayaka Langley BL (Nippon Kayaku Co., Ltd.) 15 g / l Then, the dyed material thus obtained was passed through a needle cloth raising machine three times to scrape substantially undyed fibers inside the sheet to the surface. The obtained fiber napped sheet-like material had a mixture of naps dyed on the surface and naps that were not substantially dyed, and had an animal hair-like texture with an excellent texture.

Example 3 As a sea component, 5 parts of 6-nylon (microfiber B) and 35 parts of polyethylene were melted in the same melting system, and as an island component, 60 parts of 6-nylon (microfiber A) were separated. The melted material in the system was spun so that the number of islands would be 50 by the method of defining the fiber shape in the spinneret and spinning, to obtain ultrafine fiber-generating fibers having a fineness of 10 denier. At this time, when observing a cross section with a fiber, the average number of the ultrafine fibers B was about 50, and the ultrafine fibers A and the ultrafine fibers B were almost uniformly dispersed. The obtained fiber was stretched 3.0 times, crimped, and then cut into a staple having a fiber length of 51 mm. When the cross section of this fiber was observed with an electron microscope, the average fineness of the ultrafine fiber A was 0.060 denier and the average fineness of the ultrafine fiber B was 0.003 denier. Next, after defibrating with a card, a web was formed with a cross wrap webber, and a fiber entangled non-woven fabric with a basis weight of 650 g / m 2 was obtained by needle punching. This fiber entangled non-woven fabric has a polyurethane elastomer 13 mainly composed of polyether polyurethane.
% Dimethylformamide solution, coagulate, wash with water,
Then, polyethylene was dissolved and removed in toluene to obtain a fibrous substrate having a thickness of about 1.3 mm. This base material is # 18
Buffing with 0 and # 240 sandpaper, 80 ℃
It was put into the following dyeing bath maintained at the temperature of 3 for 3 seconds and dried. (Dyeing bath) Dye: Irgallan Yellow GRL (Ciba Geigy) 2
5 g / l Kayaka Langley BL (Nippon Kayaku Co., Ltd.) 15 g / l Then, the dyed material thus obtained was passed through a needle cloth raising machine three times to scrape substantially undyed fibers inside the sheet to the surface. The obtained fiber napped sheet-like material had a mixture of naps dyed on the surface and naps that were not substantially dyed, and had an animal hair-like texture with an excellent texture.

Comparative Example 1 The fibrous substrate obtained in Example 3 was dyed for 1 hour at 90 ° C. in the following dyeing bath using a Wins dyeing machine and dried. (Dyeing bath) Dye: Irgallan Yellow GRL (Ciba Geigy)
2.5% owf Kayaka Langley BL (Nippon Kayaku Co., Ltd.) 1.5% owf Level dyeing agent: 1 g / l Bath ratio: 1:50 Then, the dyed material obtained is passed through a needle cloth raising machine three times, The substantially undyed fiber inside the sheet was scraped to the surface. The obtained fiber napped sheet-like material had an excellent feeling of texture, but the surface was covered with dyed napped hair, and the desired appearance was not obtained.

Comparative Example 2 The dyed material obtained in Example 3 was buffed with No. 180 sandpaper to form naps, but the hairs did not stand up and the surface became lumpy, giving the desired appearance. Was not obtained.

[0026]

EFFECTS OF THE INVENTION The fiber napped sheet-like product of the present invention has a nap that is dyed on the surface and a nap that is not dyed are irregularly mixed, has a good fastness, and has a texture with excellent fullness,
It is suitable for applications such as shoes and bags.

Claims (2)

[Claims] 1. A leather-like napped sheet mainly composed of ultrafine fibers having an average fineness of 0.1 dr or less and a polyurethane polymer, in which the inner layer portion is not substantially dyed and the surface is dyed napped hair. , Suede-like artificial leather characterized by a mixture of undyed naps. 2. A suede-like sheet mainly composed of ultrafine fibers having an average fineness of 0.1 dr or less and a polyurethane polymer is dyed substantially only on the surface of the sheet, and then the inside of the sheet is dyed substantially. A method for producing a suede-like artificial leather, which comprises scraping a part of non-existent fibers to the surface.