JPH0242947B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a leather-like sheet-like structure that has a natural leather-like feel and has a melazine-like hue or a large hue change such as different hues on the front and back sides. It is something.

In order to obtain a sheet-like structure with a natural leather-like feel, especially a suede-like feel, it is generally essential to manufacture the sheet-like structure from fibers of 0.5 denier or less. By using this method, a sheet having a unique slimy feeling similar to natural leather and a so-called lighting effect can be obtained for the first time. However, it is extremely difficult to directly form microfibers into sheets; for example, when trying to form a web by placing 0.5 denier staple fibers on a card, most of the staple fibers sink into the card. It stops coming out and web formation is practically impossible.

In order to avoid the difficulty of directly forming a web using ultrafine fibers, short fibers made of composite fibers with a relatively large single fiber fineness are made, and after forming a web using a conventional method, each A method for producing a nonwoven fabric made of short fibers with a small single fiber fineness by dividing each composite component or dissolving and removing one of the composite components, and a method for producing a sheet from sheath-core type composite fibers having a multifilament structure by a conventional method. Various methods have been proposed, such as a method in which the sheet is formed and the sheath component is removed by treating the sheet with a dissolving agent or a decomposing agent for the sheath component, and a method in which an ultrafine fiber sheet with a coarse structure is densified by post-processing. However, the biggest problem with these conventional techniques is that the products obtained lack diversity in variety. The present applicant previously proposed a method for solving the above problems in Japanese Patent Application No. 51-82660 (Japanese Patent Publication No.
No. 55-47153), but the sheet-like structures obtained by this method still lack diversity in appearance, similar to the sheet-like structures produced by the prior art method described above. It was hot. Recent market demands are for products that are diversified in terms of hue and appearance, and meeting these demands has become an important point for market expansion.

The present inventors have arrived at the present invention as a result of intensive studies from this point of view, and the gist of the invention is that the single fiber fineness is 0.5 denier or less,
A leather-like sheet-like structure characterized in that a plurality of paper webs made of ultrafine fibers with a fiber length of 1 to 10 mm and having different dyeability and a base fabric are intertwined and integrated by the action of a columnar flow of high-pressure liquid. It is in the manufacturing method.

To explain the present invention in more detail, first, a web made of ultrafine fibers is formed by a papermaking method, but in this case, each web must be composed of a single type of fiber, and two or more types of ultrafine fibers are used. If paper is made by mixing these, not only will problems arise in terms of dispersibility and uniformity, but it will also become impossible to obtain a product with the variety that is the objective of the present invention.

Next, the web made of the single fiber obtained is laminated on the base fabric, but in this case, fiber webs with different dyeability may be laminated on the front and back sides, the number of layers may be varied, and the number of layers may be varied. By variously changing the pressure of the liquid mentioned in the process, it is possible to create a melange-like hue effect ranging from large to small, with different hues on the front and back, or from dense to wild appearance. We can create a wide variety of products.

Examples of combinations of paper webs with different dyeability for use in the present invention include the following.
That is, combinations of different types of synthetic fibers, such as acrylic fibers and polyester fibers, polyester fibers and polyamide fibers, etc., and even the same fibers with different dyeability, such as regular type and cationic fibers in polyester fibers. It is a combination of paper webs made of a regular type and a more dialable type made of acrylic or nylon fibers, or those of different fineness by taking advantage of the difference in color development.

The ultrafine short fibers used in the present invention can be produced by various methods as described below. That is, (a) a method of wet spinning a fiber-forming polymer using a spinneret made of a sintered metal fiber sheet with a filtration accuracy of 15μ or less, drawing it, and cutting it; A method of cutting after stretching, or a method of carrying out normal stretching after ultra-stretching, and then cutting. A method of dissolving and removing the sheath component before or after cutting the core composite fiber; (d) A method of dissolving and removing the sheath component before or after cutting the core composite fiber; (e) A method of dissolving and removing one of the polymer components after cutting, (e) A method of dissolving and removing one of the polymer components before cutting an easily splittable conjugate fiber made of two types of polymers with low compatibility with each other as described in Japanese Patent Publication No. 48-28005. or splitting after cutting by mechanical action and/or the action of a swelling agent, etc. Ultrafine short fibers produced by these methods inevitably become single fibers when dispersed in a liquid during the papermaking process. separated into two parts.

When selecting the fiber length of the ultrafine short fibers, consideration must be given to the dispersibility in liquid during the papermaking process, papermaking properties, and the feel of the resulting product. In other words, it is recognized that the longer the fiber length, the lower the uniform dispersibility in the liquid, but on the other hand, the entanglement between the fibers is improved by the jet fluid treatment, and the resulting product is finer in post-processing, such as in the napping process. It is possible to suppress the shedding of short fibers, and it is also possible to diversify the performance of the obtained product in terms of sliminess, writing effect, texture, and feel. Furthermore, if the fiber length is shortened, the dispersibility of the ultrafine short fibers in the liquid during the papermaking process will improve and the papermaking properties will be relatively good, but on the other hand, the entanglement between the fibers due to liquid injection will decrease. The shedding of the ultrafine staple fibers from the products obtained by this process increases, and the variety of textures and textures of the products obtained is restricted due to the short pile length.

The fiber length of the ultra-fine short fibers is generally selected in the range of 1 to 10 mm, taking into consideration the ease of production and product performance mentioned above, but specifically, the fiber length is selected in the range of 1 to 10 mm, depending on the single fiber denier. also changes. For example, the preferred fiber length range for ultrafine short fibers of 0.5 denier is 2 to 10
mm, 2 to 5 mm for 0.2 denier ultrafine short fibers,
The length is 1 to 3 mm for ultrafine short fibers of 0.05 denier, and 1 to 2 mm for ultrafine short fibers of less than 0.05 denier.

The ultrafine short fibers obtained in this way are dispersed in a liquid, and the liquid used is generally water. Of course, any liquid other than a solvent for the fiber polymer may be used. When water is used, the appropriate fiber concentration in water is usually 0.001% to 0.05%; if the concentration is higher than this, the fibers dispersed in water will become entangled, making it difficult to form a uniform paper, and the resulting web will have a poor becomes inferior. The dispersion of ultrafine short fibers thus obtained is formed into a web in the next step. Next, the process moves on to layering this paper web on another fiber base fabric.The base fabric to be laminated with the ultrafine staple fiber web used here is one with a relatively stable structure, such as knitted fabric, woven fabric, or non-woven fabric. Any type of base fabric may be used, but by appropriately selecting the base fabric, it is possible to give the final product a wide variety of performance and texture.

In other words, if a base fabric with relatively high apparent density and large basis weight is used, when the laminate of the ultrafine staple fiber web and the base fabric is treated with the jetting liquid described later, the ultrafine staple fibers will not penetrate through the base fabric. Since the fibers are intertwined only on one side of the base fabric, the resulting sheet has a layer of ultrafine single fibers on only one side.

On the other hand, if a base fabric with a relatively low apparent density and a small basis weight is used, when a laminate of the base fabric and the ultra-fine single fiber web is subjected to liquid injection treatment, some of the ultra-fine short fibers will be absorbed by the action of the injection liquid. , it penetrates through the base fabric and reaches the opposite side of the base fabric, so the resulting sheet has layers of ultrafine short fibers on both sides.

In the present invention, the ultrafine short fiber web and the base fabric are integrated by a liquid jetting process.

In the liquid jetting process, a fluid is directly jetted onto a laminate placed on a support member such as a net or a roll. The supporting member used in this case has a substantially smooth surface and no pattern of the supporting member is formed on the laminate.
Moreover, any material can be used as long as the injected liquid can be quickly removed. In addition, in the case of net treatment, water removal can be carried out more effectively by using a suction.
If the support member has large irregularities, a pattern will be formed on the laminate by the liquid jet treatment, which will significantly limit its range of use and make it impossible to obtain a versatile base fabric, which is not preferred in the present invention. .

In addition, the injected fluid needs to be quickly separated from the laminated body, and if the fluid partially stagnates in the laminated body, the confounding and unifying effect due to the liquid jet becomes smaller in the stagnant part of the fluid, and becomes noticeable. This causes spots.

If most of the liquid remains in the laminate and the laminate is immersed in the liquid, the entangling and unifying effect of liquid jetting will no longer be observed, and the ultrafine short fibers will separate and flow out from the laminate. Therefore, the sprayed liquid must be quickly removed from the laminate.

Although any liquid other than the solvent for the treated fibers can be used for the liquid jet treatment, water or warm water is preferred because of its ease of handling.

It is also possible to add a small amount of liquid additives to increase the effect of liquid jetting.

The shape of the sprayed liquid is preferably a thin columnar flow, and the pore diameter of the spray nozzle is usually 0.06 to 1.0 mm, preferably 0.1 mm.
~0.3mm. The pressure of the liquid used is usually 5~
The pressure is 35 kg/cm ² , but it varies depending on the processing speed of the web, and the preferred pressure increases as the processing speed increases. If the pressure is too low, a sufficient entangling effect will not be obtained, and if the pressure is too high, it will not only be economically disadvantageous, but also leave traces of fluid treatment, destroy the shape of the ultrafine short fiber layer, and seriously impair the appearance. Undesirable.

The appropriate distance between the injection hole and the web is about 1 to 15 cm; as the distance increases, air gets mixed into the injection liquid, reducing the entangling and unifying effect of the injection liquid.

As is clear from the above description, the basic structure of the present invention is the lamination of an ultra-fine short fiber web obtained by papermaking and a base fabric, and the subsequent liquid injection treatment. By repeating the above steps, there is an advantage that a wide variety of products can be produced using the same method, ranging from products with different hues and changes in appearance to products with different fabric thickness and basis weight.

The composite sheet-like structure thus obtained is then dried. Then, dyeing, heat setting, finishing treatments, etc. are performed in the same way as general base fabrics.

In dyeing, if different fibers are mixed, it is possible to perform different color dyeing by changing the dye, or to dye only one side and leave the other white.

In the case of mixing fibers using slight differences in dyeing seats or mixing fibers of different fineness, a difference in density will appear just by dyeing with one type of dye, and a product with a deep mix-like hue can be obtained.

Since the sheet-like structure obtained in the present invention is particularly characterized by drapability, it is sufficient to finish it by impregnating it with a small amount of elastomer resin that does not impair the drape property. Furthermore, since the sheet-like structure obtained by the present invention is in a state in which the base fabric and the ultrafine short fibers are intertwined and integrated, the constituent threads or constituent fibers of the base fabric and the ultrafine short fibers from the cutting point are not frayed or It also has excellent properties in terms of secondary processing, such as almost no shedding.

The present invention will be explained in more detail with reference to Examples below.

Example 1 An acrylonitrile copolymer containing 93% by weight of acrylonitrile and 7% by weight of vinyl acetate and having an intrinsic viscosity of 1.7 measured in dimethylformamide at 25°C was dissolved in dimethylacetamide to prepare a stock solution with a polymer concentration of 16% by weight. 60% by weight of dimethylacetamide was used as a spinneret using two stacked Pall Filter Dimesh sheets (manufactured by Pall Trinity Micro Co., Ltd.) with a filtration accuracy of 5μ, which are made by sintering stainless steel fibers. Wet spinning was carried out in an aqueous solution at 35° C. at a take-up speed of 5 m/min. Subsequently, the tow was stretched 3 times in boiling water to obtain an ultrafine fiber tow with an average single fiber fineness of 0.1 denier and a total fineness of 4200 denier.

This tow was cut into 3 mm pieces, poured into water to prepare a dispersion having a fiber concentration of 0.01% by weight, and paper-formed using a wire mesh to obtain an acrylic fiber web having a basis weight of 25 g/m ² .

On the other hand, a mixed spun fiber consisting of 40 parts of nylon 6 and 60 parts of polystyrene was cut into 2 mm pieces, and the polystyrene was eluted by toluene treatment to obtain an average single fiber fineness.
Nylon 6 ultrafine short fibers of 0.02 denier were obtained. These ultrafine short fibers are dispersed in water to make a 0.005% by weight ultrafine short fiber dispersion, which is then made into paper using a wire mesh.
A nylon fiber web having a basis weight of g/m ² was obtained. Furthermore, a tricot knitted fabric was separately knitted using 50d/24f polyester filament having a latent shrinkage of 35% in boiling water.

First, two sheets of the above-mentioned acrylic fiber web were layered on this knitted fabric, and then subjected to columnar flow treatment with water on a belt conveyor made of 60 mesh wire mesh.

The injection nozzle for columnar flow treatment has a hole diameter of 0.12 mmφ, and the pressure is 15 Kg/cm ² G at the beginning and 30 Kg/cm ² G at the second time.
I went there. Next, two sheets of the above-mentioned nylon fiber web were superimposed on the back side of this sheet, and then fluid treatment was performed in the same manner as above.

The base fabric was then shrunk in boiling water. The resulting sheet was dried and then dyed.

Acrylic fibers were dyed with cationic dyes, and nylon fibers were dyed with acidic dyes in different colors.

After that, it was treated with a small amount of water-soluble urethane solution and then sanded with sandpaper to create a leather-like sheet with a density of 0.32 g/cc, close to natural leather, but with different hues on both sides, so both sides can be used. was gotten.

Example 2 One sheet of the acrylic fiber web obtained in Example 1 was subjected to fluid treatment using the same method, and then two sheets of nylon fiber web were stacked from the back side of the sheet and subjected to fluid treatment, and then one sheet of acrylic fiber web was placed on top of this. Fluid treatment was repeated in the same manner. Thereafter, they were dyed in the same manner as in Example 1, with the acrylic fibers being dyed deep brown and the nylon fibers being dyed pale beige.

Next, the same finishing as in Example 1 was performed to obtain a density of 0.35.
A natural leather-like sheet of g/cc was obtained.

This sheet was a leather-like sheet-like material with a deep melange-like color effect that was unprecedented, with the fuzz portion on the front being a mixture of dark brown and light brown.

Example 3 Ultrafine fiber tows of 0.1 denier and 0.5 denier acrylic fibers were obtained in the same manner as in Example 1.

This toe is 3mm for both 0.1 denier and 0.5 denier.
Cut into 0.1 denier and 0.5 denier using the same method as above.
Paper is made separately from denier, and 0.1 denier is 22
Web with a basis weight of g/m ² , 0.5 denier is 35 g/m ²
I obtained a web with a weight of .

Separately, a knitted fabric with a fabric weight of 120 g/m ² was knitted using acrylic fiber filament 180d/60f woolly processed yarn, and one 0.5 denier web was first laminated on one side of this knitted fabric, and then the same method as in Example 1 was used. Fluid treatment was performed.

The fluid pressure at this time was 20Kg/cm ² G.

Next, two sheets of 0.1 denier web were superimposed on the back side, and fluid treatment was performed in the same manner at a pressure of 30 kg/cm ² G. This composite sheet was dyed with a cationic dye and then finished in the same manner as above to obtain a natural leather-like sheet weighing 180 g/m ² .

The surfaces of the products obtained in Examples 1 and 2 had a very dense and delicate appearance, whereas the surfaces of the products obtained in this Example had a strong wild appearance.
There was a difference in hue due to the difference in color between 0.1 denier and 0.5 denier, making it a unique product not seen in conventional suede-like fabrics.

Claims (1)

[Claims] 1 Single fiber fineness is 0.5 denier or less, fiber length is 1
A method for manufacturing a leather-like sheet-like structure, characterized by intertwining and integrating a plurality of paper webs made of ultrafine fibers of ~10 mm with different dyeability and a base fabric by the action of a columnar flow of high-pressure liquid.