JPH0124901B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel method for producing artificial leather.

[Conventional technology]

The present inventors have already developed a woven structure in which ordinary denier fibers are used for the ground texture (warp threads) and many weft threads appear on the surface, and composite fibers are used for the weft threads, and the composite fibers are made extremely fine. A suede-like material having ultrafine fiber naps on the surface was provided. In addition, after forming a needle-punched nonwoven fabric using composite fibers, it undergoes many complex processing steps such as shrinkage treatment, shape fixation (gluing) treatment, resin impregnation, coagulation treatment, solvent removal and desizing treatment, slicing, buffing, and resin coating. We have clarified a method for manufacturing artificial leather by passing it through.

These suede-like artificial leathers have been highly praised for their soft touch, stiffness, and motility on the surface, and are attracting attention and excitement in the fashion world as new suede-like materials. Taking this opportunity, synthetic fiber companies began competing to process the products, but depending on the intended use, they developed high value-added products that required further improvement in terms of durability, and also added functionality and a sense of luxury. is desired.

In addition, the conventional known manufacturing method involves many processing steps and requires complicated process control for each step, which is quite disadvantageous in terms of processing yield and cost, and the need for improvement has been pointed out.

On the other hand, we are developing new structures by laminating composite fiber webs on ordinary denier woven and knitted fabrics, providing an adhesive layer between the woven and knitted fabrics and the webs, or entangling them with needles or waterjet punches. have been attempted, and some have even been commercialized and put on the market.

However, these are the differences between woven and knitted fabrics and webs.
It has a poor physical sensation and is easily peeled off or peeled off at the adhesive layer, and at the same time, it has a hard texture due to the adhesive layer, and there are drawbacks to its durability, and considerable improvements in these areas are desired in the future.

[Problem that the invention seeks to solve]

The present invention has been achieved as a result of intensive studies aimed at solving the above-mentioned problems, improvements desired, and difficulties.

An object of the present invention is to provide a method for producing artificial leather that is advantageous in terms of yield and cost, by maximally simplifying a large number of steps that require complicated process control.

[Means for solving problems]

The gist of the present invention is as follows. That is, (1) a composite fiber made of two or more polymers, at least one of which is a water-soluble polymer, is used in a portion forming at least one surface of the fabric, and after the fabric is formed, a waterjet punch treatment is performed. Features: A manufacturing method for artificial leather.

(2) Composite fibers made of two or more polymers, at least one of which is a water-soluble polymer, are used in a portion forming at least one surface of the fabric, and after the fabric is formed, it is impregnated with a wet coagulable polymeric elastic material. ,
This is a method for producing artificial leather, which is characterized in that it is then subjected to waterjet punching treatment.

The present invention will be further explained in detail.

The water-soluble polymer referred to in the present invention is a polymer that can be melt-spun and may be any polymer that can be easily dissolved in water or hot water, such as polyvinyl alcohol (PVA)-based polymers, water-soluble polyamides (such as polyether There are amide polymers, polyether ester amide polymers) water-soluble polyesters (e.g. copolymerized polyester polymers of sodium salt of 5-sulfoisophthalic acid), etc., but they can be selected as appropriate depending on the purpose, and any of the known water-soluble polymers can be used. is preferably used.

In the present invention, this water-soluble polymer is used as at least one component, and is used as a composite fiber consisting of two or more polymer components. This composite fiber may be any type of composite fiber as long as it is a type of composite fiber that is waterjet punched in the processing described below, and the remaining water-insoluble components become ultra-fine fibers by removing the water-soluble polymer, such as sea-island composite fibers, Composite fibers such as hollow annular composite fibers, mixed spun composite fibers, split composite fibers, multicore composite fibers, and composite fibers with grain-like, mosaic, radial, or side-by-side fiber cross sections are preferably used as appropriate depending on the purpose.

In the present invention, it is necessary to use a water-soluble polymer as at least one component of the composite fiber consisting of two or more polymer components, and the other components are polymers that can be melt-spun into composite fibers and then turned into ultrafine fibers by subsequent processing.
In other words, a polymeric substance having fiber-forming ability is preferable. For example, nylon 6, nylon 66, nylon
12. Polyamides such as copolymerized nylon, polyesters such as polyethylene terephthalate, copolymerized polyethylene terephthalate, polybutylene terephthalate, and copolymerized polybutylene terephthalate, polyolefins such as polyethylene and polypropylene, polyurethane, polyacrylonitrile, and vinyl polymers can be used depending on the purpose. , is appropriately and preferably used.

Next, these composite fibers are used in a portion forming at least one surface of the fabric to form a fabric, and the fabric in the present invention includes woven fabric, knitted fabric, nonwoven fabric, woven fabric and woven fabric, woven fabric and knitted fabric, knitted fabric and knitted fabric, woven and non-woven fabrics,
Laminated fabrics that are a combination of knitted fabrics and non-woven fabrics, as well as sandwich-type fabrics that are a combination of each, such as sandwich fabrics that have a woven or knitted fabric inserted between two non-woven fabrics, and sandwich fabrics that have a non-woven fabric inserted between woven or knitted fabrics. Any fabric in which at least one surface is formed of a composite fiber containing a water-soluble polymer can be preferably used. Particularly preferred is a fabric whose surface is made of a nonwoven fabric.

The nonwoven fabric may be in the form of a web, but since unevenness may occur during handling, it is preferable to use one that has been needle punched.

In the present invention, a fabric is formed by using the conjugate fibers in a portion forming at least one surface of the fabric, and then subjected to waterjet punching treatment. The waterjet punch referred to in the present invention is a method in which liquid is pressurized and jetted from a nozzle with a small hole diameter or a narrowly spaced slit to form a high-speed columnar flow or curtain-like flow, and the fabric surface is treated with this high-speed pressurized liquid flow. be.

A typical liquid is water, which may be heated or heated water, and auxiliary agents that promote dissolution and removal of water-soluble polymers contained in composite fibers, such as organic solvents, surfactants, and acids. , an aqueous solution containing an alkali or the like is preferably used as appropriate depending on the purpose.

The pressure applied to the liquid varies depending on the surface condition of the fabric to be treated, that is, the desired surface condition, but can be freely selected in the range of 5 to 300 Kg/cm ² , with a preferable range of 30 to 200 Kg/cm ² A particularly preferable range is 50 to 150 Kg/cm ² .

If it is less than 5 Kg/cm ² , the effect of entangling the conjugate fibers and the effect of making the fibers finer are small, and favorable results cannot be obtained. Also
If the pressure exceeds 300 Kg/cm ² , special pressure-resistant equipment will be required, and the fibers on the surface of the fabric may break or the fabric may tear, which is undesirable.

The waterjet punch treatment may be carried out only once, but it is preferable to carry out the treatment multiple times from the front or back side in order to completely remove the water-soluble polymer in the composite fibers. In this case, it is preferable to change the pressure for each treatment, change the specs of the nozzle and slit, or vibrate or swing the nozzle and slit from side to side and back and forth as appropriate depending on the purpose.

Furthermore, depending on the purpose, it may be preferable not to completely remove the water-soluble polymer in the composite fibers, but to leave a portion of the water-soluble polymer in the composite fibers as a binder, that is, a binder between the fibers.

The present invention provides ultra-fine treatment of composite fibers in a fabric, entangling treatment of fibers forming the fabric by performing such a waterjet punch treatment,
The feature is that the shrinkage treatment of the fabric is performed at the same time.

In other words, the ultra-fine treatment is the process of dissolving or decomposing and removing the water-soluble polymer in the composite fibers forming at least one surface of the fabric using a high-speed pressurized liquid flow using a waterjet punch to form ultra-fine fibers. This means that the fibers forming the fabric are randomly entangled with each other by a high-speed pressurized liquid flow, creating a dense intertwined state of fibers. In addition, shrinkage treatment is a process in which the fibers are randomly entangled due to high-speed pressurized liquid flow treatment, increasing the fiber density of the fabric, resulting in the fabric shrinking in the area and thickness direction. By using hot water, the fibers themselves are made to shrink, causing the fabric to shrink.

In the prior art, processing was carried out using separate equipment for each process and performing complex process management for each process.

This is achieved by using the manufacturing method of the present invention.
The process can be simplified, and furthermore, it can be easily processed because it does not require complicated conditions.
In other words, processing is possible by controlling the temperature of the liquid in the water jet punch, the selection of the liquid (type of aqueous solution), the pressure, and the number of processing times in accordance with the processing purpose.

Furthermore, in the present invention, if the fabric is impregnated with a wet-coagulable elastomer before waterjet punching, and the waterjet punching is then immediately performed, the elastomer can be coagulated at the same time. It can be done. Needless to say, at this time, ultrafine treatment, entangling treatment, and shrinkage treatment are performed simultaneously.

In the present invention, the wet-coagulable polymeric elastomer may be in the form of a solution containing a water-compatible liquid, a colloid, or a dispersion such as an emulsion, latex, or dispersion. Examples include polyurethane, nitrile butadiene rubber, polyvinyl chloride, polyvinyl acetate, polyamide, natural rubber, and polyurethane is particularly preferred.

It goes without saying that the fabric processed by the above-mentioned means can be subjected to conventional processes such as woven or knitted fabrics, non-woven fabrics, etc., such as setting, dyeing, finishing setting, and finishing.

The fabric obtained by the present invention can be used in a wide range of applications such as clothing, furniture, interior decoration materials, and industrial materials.

〔Example〕

Next, examples according to the present invention will be shown, but these are intended to clarify the present invention, and the present invention is not limited or restricted thereby.

Example 1 The composite fiber is a sea-island type composite fiber, the island component is polyethylene terephthalate, the sea component is an equimolar salt of α, ω-diaminopolyoxyethylene and adipic acid: 55 parts by weight, ε-caprolactam: 30 parts by weight A copolymerized polyamide of polyetheramide obtained by melt-polymerizing 15 parts by weight of equimolar salts of hexamethylene diamine and adipic acid at 250° C. for 15 hours was used to prepare composite fibers having the following content.

Number of islands: 16 Island component ratio: 80% Sea component ratio: 20% Denier: 2.8d Fiber cut length: 51mm Number of crimps: 12 crimp/in This sea-island type composite fiber cotton is used to form a web by the cross lapping method, and then 1500 crimp/cm ²
An entangled nonwoven fabric having a basis weight of 245 g/m ² and an apparent density of 0.13 g/cm ³ was prepared by needle punching.

Next, this nonwoven fabric was subjected to waterjet punching treatment. The conditions for this treatment are that hot water controlled at 90℃ is sprayed at a pressure of 30Kg/cm ² from a nozzle with a row of small holes with a pitch of 1.5mm and a diameter of 0.2mmφ, twice at 0.8m/min on each side. contact at a speed of

Next, increase the pressure to 80Kg/cm ² and apply 3 times on each side.
Processing was performed at a speed of 1.3m/min. Finally, to make punch lines, use a pressure of 80Kg/cm ² and a speed of 0.3m/mi.
A total of 12 passes were carried out, once on each side. As a result, it was possible to perform ultrafine treatment by removing sea components, fiber entanglement treatment, and shrinkage treatment at the same time.

The treated nonwoven fabric was subjected to two-stage drying at 140°C and 180°C and heat setting treatment. This nonwoven fabric was a suede-like artificial leather whose surface was covered with fine napped piles made of ultrafine fibers. The nonwoven fabric had a basis weight of 258 g/m ² and an apparent density of 0.19 g/cm ³ . The area shrinkage rate was 30%.

Furthermore, the residual rate of sea components was analyzed and was found to be 0.18%.
It was confirmed that almost all sea components were removed.

Example 2 A sea-island composite fiber with the same specifications as in Example 1 was made, except that a copolyester consisting of terephthalic acid: 70 mol%, isophthalic acid: 17 mol%, and 5-sodium sulfoisophthalic acid: 13 mol% was used as the sea component. .

This composite fiber cotton was formed into a web by the cross-lapper method to obtain a needle-punched nonwoven fabric with a density of 500 fibers/cm ² . This non-woven fabric has a basis weight of 80g/
m ² and an apparent density of 0.09 g/cm ³ .

A coarse woven fabric with a basis weight of 50 g/m ² (both the warp and weft yarns use 30 denier 12 filaments of Tetoron filament) is spread evenly on this non-woven fabric, and the above-mentioned non-woven fabric is then placed on top of it to form a three-layered sandwich-like sheet. It was made into a shape.

This sheet-like material was impregnated with a 12% polyurethane solution of dimethylformamide (DMF), and the solution was squeezed so that 20 parts by weight of polyurethane was attached to the sheet-like material.

Subsequently, this sheet-like material was subjected to water jet punching treatment. The conditions for this treatment include hot water controlled at 80℃ and a pressure of 20Kg/cm ^2. A high-pressure water stream is continuously ejected from a nozzle with a row of small holes with a pitch of 1.0mm and a diameter of 0.15mmφ, once on each side. brought into contact. At this time, the impregnated polyurethane solidified. Next, the pressure was increased to 40 Kg/cm ² and the front and back sides were treated three times each, and finally the front and back sides were contacted once each at a pressure of 80 Kg/cm ² . Processing speed is everything
A total of 10 passes were carried out at 0.8 m/min. As a result, it was possible to perform coagulation treatment, ultra-fine treatment by removing sea components, fiber entanglement treatment, and shrinkage treatment at the same time.

When the cross section of the three-layered sheet treated with high-pressure water jet treatment was observed, it was found to be a single-layered sheet with densely intertwined fibers. The basis weight of this item is 255
g/m ² and an apparent density of 0.23 g/cm ³ , and the area shrinkage rate due to this treatment was 12%.

The surface of this sheet was covered with extremely soft-touch ultrafine naps in which the water-soluble polymer used for the composite fibers had been removed and the ultrafine fibers were tightly entangled.

This sheet material was set in a pin tenter dryer at 180°C, and then dyed blue using a disperse dye in a high-pressure jet dyeing machine. After applying the softening agent, the surface was finished and dried at 120°C while brushing.

This sheet-like material had a soft touch, an artificial suede-like sheet material, and had a soft texture and a surface gloss that produced a unique chiyoke mark.

Example 3 The composite fiber was a sea-island type composite fiber, and the island component was polyethylene terephthalate, and the sea component was a copolymerized polyester consisting of terephthalic acid: 68 mol%, isophthalic acid: 17 mol%, and 5-sodium sulfoisophthalic acid: 15 mol%. The filament yarn had an island component ratio of 90%, a sea component ratio of 10%, and a 50-denier 10 filament (a composite fiber single yarn of 50 denier) with 70 island fibers.

This sea-island type composite fiber filament yarn is used as warp yarn,
The weft was used to create a plain weave woven fabric. At this time, the warp yarn was 180T/M S-twisted and warped with glue, and the weft yarn was the stretched filament yarn as it was.
Using WJL, warp thread density 118/in, weft thread density
It was woven with a standard of 107 strands/in. The basis weight of this fabric was 57 g/m ² .

This woven fabric was used for the upper and lower layers, and the fabric weight obtained in Example 2 was 80 g/m ² and the apparent density was 0.09 between the woven fabrics.
A sheet-like product in the form of a sandwich sandwich was prepared by inserting a nonwoven fabric of g/cm ³ .

Hot water controlled at 95℃ is sprayed onto this sheet-like material from a nozzle with small holes of diameter 0.13mmφ arranged in a row at a pitch of 1.0mm as high-pressure hot water of 50Kg/cm ² at a processing speed of 1m/min on both sides. 8 times total
I processed the circulation. As a result, it was possible to perform ultrafine treatment by removing the sea component of the composite fiber, fiber entanglement treatment, and shrinkage treatment at the same time. At this time, the basis weight was 203 g/m ² and the apparent density was 0.20 g/cm ³ .
The area shrinkage rate was 15.3%.

The texture of the fabric was visible on the front and back sides of this sheet-like material, but it was made of very short, ultra-fine fibers with dense naps, and had a soft touch surface and a flexible texture, making it ideal as a clothing material.

〔Effect of the invention〕

The artificial leather production method of the present invention allows for ultra-fineness, entanglement, and
Shrinkage and solidification of the elastomer polymer can be performed in one step, which simplifies the process and is advantageous in terms of cost.

Furthermore, as a method for obtaining ultrafine fibers from conventional composite fibers, the multicomponent composite fibers are treated with polymer solvents that remove at least one component, such as liquids that are harmful to the human body, such as formic acid, strong alkali, and trichlorethylene. However, with the present invention, we have discovered a method that is safe and does not harm the human body.

Claims (1)

[Scope of Claims] 1. Composite fibers made of two or more polymers, at least one of which is a water-soluble polymer, are used in a portion forming at least one surface of the fabric, and after the fabric is formed, a waterjet punch treatment is performed. A method for producing artificial leather characterized by: 2. A composite fiber consisting of two or more polymers, at least one of which is a water-soluble polymer, is used in a portion forming at least one surface of the fabric, and after the fabric is formed, it is impregnated with a wet coagulable polymer elastic body, and then A method for producing artificial leather, characterized by carrying out waterjet punching treatment.