JPH11200219A - Production of base fabric for artificial leather and flexible artificial leather with improved stretch stop feeling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject base fabric capable of giving flexible artificial leathers with improved stretch stop feeling, by overcoming such critical drawbacks inherent in crimped short synthetic fibers that flexible, high-density artificial leather base fabrics have been difficult to produce so far on account of being influenced by percentage crimp. SOLUTION: This base fabric (continuous fiber-interlaced nonwoven fabric) is obtained by the following method: the above kind of nonwoven fabric is made to have the requirements A to C described below: (A) the percentage crimp of continuous fibers comprising the nonwoven fabric is <=10%; (B) continuous fibers comprising the nonwoven fabric are capable of raising superfine fibers each <=0.5 denier in fineness; and (C) the fiber density of the nonwoven fabric is 0.25-0.50 g/cm3 . Besides, the nonwoven fabric as a base fabric for artificial leathers is impregnated with a solution of polymeric elastomer followed by solidifying the elastomer in water; in this case, before and after the solidification step, superfine fibers each <=0.5 denier in fineness are raised from the continuous fibers comprising the base fabric, that is, a processing for converting the continuous fibers to superfine fibers is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base fabric for artificial leather which provides artificial leather which is soft and has an excellent stretch stopping feeling.

[0002]

2. Description of the Related Art A crimped single fiber having a length of 100 mm or less, which is a composite spin of polyamide or polyester and a polyolefin, is formed into a web through a card, and the web is subjected to entanglement treatment by needle punching or high-pressure water flow. After that, the polymer elastic body is impregnated and coagulated, and then the polyolefin in the single fiber is extracted to obtain a suede-like artificial leather, and the production of an artificial leather having a silver coating by providing a coating layer on the surface of the suede The technology is widely known. In addition, after crimping short fibers composite-spun using polyamide and polyester are formed into a web through a card, entanglement and splitting are performed by needle punching or high-pressure water flow, or splitting is performed after entanglement. It is also known to impregnate and solidify a polymer elastic body after making it ultrafine.

[0003] These techniques are based on imitation of natural leather, but as is well known, natural leather has a texture that is flexible and has a feeling of having no stretch because the constituent fibers are very fine and the density of fiber aggregates is high. . On the other hand, it is generally difficult to obtain a nonwoven fabric having a high fiber aggregate density in a nonwoven fabric obtained by subjecting crimped short fibers of synthetic fibers to entanglement by means such as needle punching. This is due to the fact that the porosity of the crimped short fiber aggregate is large, and the improvement of the fiber density is limited only by the entanglement treatment of the crimped short fiber aggregate by means such as needle punching. Also, when short fibers having low crimp are used, there is a problem that the card passing property is deteriorated in the web making process. in this way,
In the case of using crimped short fibers of synthetic fibers, it is extremely difficult to imitate a soft and stretchy feeling. For this reason, it has been proposed to obtain a high-density nonwoven fabric by using a crimpable short fiber having a high shrinkage property. However, in this case, it is difficult to obtain a fine denier, or a shrinkage treatment requires several steps. The problem remains unresolved.

[0004]

DISCLOSURE OF THE INVENTION The present invention overcomes the fatal defects of synthetic fiber crimped staple fibers, which were difficult to obtain a flexible and high-density base fabric for artificial leather depending on the crimp rate, It is an object of the present invention to provide a base fabric which provides artificial leather which is soft and has an improved stretch feeling.

[0005]

According to the present invention, in a long fiber entangled nonwoven fabric, the nonwoven fabric comprises the following (A) to (C)
A base fabric for artificial leather, characterized by satisfying the following requirements. (A) The degree of crimp of the long fibers constituting the nonwoven fabric is 10% or less. (B) The long fibers constituting the nonwoven fabric can generate ultrafine fibers of 0.5 de or less. (C) The fiber density of the nonwoven fabric is 0.25 to 0.50 g / cm
³ , furthermore, a step of impregnating the above-mentioned artificial leather base cloth with a polymer elastic body solution and then coagulating the elastic body in water; and A process for producing engineered leather which is flexible and has an improved feeling of non-stretching, comprising the step of producing ultra-fine fibers of not more than .5 de and producing ultra-fine fibers.

[0006] In the present invention, the fiber density is 0.25-0.
An entangled nonwoven fabric of 50 g / cm ³ is used. Crimp degree is 1
If it is larger than 0%, the gap between the fibers is large, so that the fiber density is 0.25 g /
It is difficult to adjust to more than cm ³ .

On the other hand, in the case of a long-fiber non-woven fabric having a degree of crimp of 10% or less, the non-woven fabric is easily removed by a needle punch or the like.
It is possible to achieve a density of 25 g / cm ³ or more. For example, when a needle punch is used as the entanglement processing means,
Depending on the number of punches, the depth of the punch needles, and the type of needles, 0.
Density control of 25 g / cm ³ or more becomes possible. In this case, it is preferable to previously apply an oil agent to the fiber surface in order to prevent the fiber from being broken and the needle from being broken by the needle. By improving the fiber density of the non-woven fabric, the non-woven fabric is more excellent in anti-stretching feeling than the one using conventional crimped short fibers. However, when the density is larger than 0.50 g / cm ³ , the hard feeling of the nonwoven fabric itself becomes hard, which is not preferable. From this, the fiber density of the nonwoven fabric is 0.25 to 0.5.
50 g / cm ³ , preferably 0.25 to 0.45 g / c
m ³ is preferred.

[0008] Further, the present invention provides that the final constituent fiber is 0.5
A soft feeling is obtained by using a conjugated long fiber that becomes an ultrafine fiber of not more than de.

As one component constituting the composite long fiber, polyethylene terephthalate, polybutylene terephthalate, copolymerized polyethylene terephthalate, or the like is used such as nylon 6, nylon 66, nylon 610, and nylon 12.

As the other component, polyethylene, polypropylene and the like are generally used. Among them, polyethylene is often used because of its cost and versatility. Among polyethylenes, low-density polyethylene is preferably used because it exhibits good extractability.

As the composite long fiber capable of producing an ultrafine fiber of 0.5 de or less, a sea or island structure fiber using polyamide or polyester as a disperse phase (island component) and low density polyethylene as a dispersion medium (sea component), 0.5 de The following are mixed spun fibers composed of polyamide and polyester which can be made ultrafine, or composite fibers of a multilayer bonding type. In this case, the polyamide or polyester which finally forms the fiber aggregate may be colored by adding a pigment such as carbon in advance.

The composite filaments are melt spun and subsequently formed into a laminated web by known methods. Such a method is a conventional melt spinning, drawing, crimping,
This is one in which the process is omitted as compared with a method of forming a web by using a card after cutting to produce crimped short fibers. Further, since there is no need to pass through a card, it is possible to use a low crimped fiber or a fine denier fiber.

Next, the web is subjected to entanglement treatment by a conventionally known method such as needle punching or high-pressure water flow. At the time of needle punching, 0.5 to 5.0 wt.
%, And then needle punching is performed at 300 to 1000 P / cm ² . As for the depth of the needle, it is preferable to increase the depth within a range where the surface irregularities and the needle pattern do not appear, from the viewpoint of increasing the interlaminar peel strength between the components of the composite long fiber. As the needle needle to be used, it is more efficient to use a large number of barbs. However, the needle may be selected from 1 to 9 barbs within a range in which needle breakage and fiber cutting do not occur.

Next, the above-mentioned base cloth is impregnated with a solution of a polymer elastic material to solidify the elastic material in water. A typical example of the polymer elastic body is polyurethane. In this case, various known polyurethanes such as polyether-based, polyester-based, carbonate-based polyurethane, and diisocyanate-based diphenylmethane diisocyanate, tolylene diisocyanate, and isophorone diisocyanate are used. Can be used. Further, any of a solution type dissolved in a polar solvent such as DMF and a type dispersed in water can be applied.

What is most important in the present invention is that the composite filaments constituting the base fabric are mixed with each other before and after the coagulation step to form
It is to produce ultra-fine fibers of de or less.

In the case of ultra-slimming, in the case of sea-island structural fibers mainly composed of polyamide or polyester and polyolefin, the web is subjected to an entanglement treatment, and then the web is immersed in a solution or dispersion solution of a polymer elastic material such as polyurethane. The polyolefin may be extracted after impregnating, coating a coating layer as needed, and coagulating.

Solvents for extracting polyolefin include:
There is no particular limitation as long as it is a solvent that dissolves olefin and does not dissolve polyamide, polyester, and polyurethane. For example, general-purpose solvents such as toluene, xylene, and tricrene are exemplified, and toluene is particularly preferably used. At that time, if the solvent temperature becomes higher, the extraction effect becomes higher, so that it is generally advantageous to heat the solvent to around 80 ° C.

On the other hand, in the case of a mixed spun fiber composed of polyamide and polyester or a composite fiber of a multilayer bonding type, the web is entangled and simultaneously decomposed by a needle or a high pressure water stream, or entangled. After the treatment, it may be subjected to a decomposition treatment by a known method to make it extremely fine.

The artificial leather raw fabric thus obtained is
Furthermore, the surface is polished and dyed to provide a suede-like artificial leather which is very supple, has chalk mark properties, and is excellent in flexibility and anti-stretch feeling.

Of course, a type with silver can also be obtained. In this case, a polyurethane for finishing to which a pigment is added is applied by a gravure method to the surface of the raw material, and the surface is embossed to give a natural leather tone. By embossing and rubbing, artificial leather with very supple, flexible and anti-stretch feeling can be obtained.

[0021]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. In the examples, the measurement of each physical property was performed by the methods described below. 1. Measurement of degree of crimp: According to JIS standard L-1015 method.

Example 1 Nylon 6 and polyethylene chips were melt-spun into a 50:50 (volume ratio), then pulled by an ejector, rubbed against a metal wall, spread, and moved and collected. A web was made by depositing on the surface. The degree of crimp of the fibers in this web was 7%. Next, 2 wt% of an oil agent is applied to this web by spraying,
Needle punching was performed at P / cm ² to obtain an entangled nonwoven fabric. The density of the obtained nonwoven fabric was 0.35 g / cm ³ . Next, the nonwoven fabric was heated at 150 ° C., then impregnated with a 12% concentration polyurethane solution, wet coagulated, dried,
The polyethylene was extracted with toluene at 80 ° C. The obtained artificial leather was soft and excellent in anti-stretch feeling.

[Embodiment 2] In Embodiment 1, 300 P
/ Cm ² was subjected to needle punching to produce an entangled nonwoven fabric. Needle punching was performed at a density of 300 P / cm ² on the obtained nonwoven fabric to obtain an entangled nonwoven fabric. The density of the obtained nonwoven fabric was 0.25 g / cm ³ . Example 1
The same operation as described above was performed to produce an artificial leather. The obtained artificial leather was soft and excellent in anti-stretch feeling.

[Embodiment 3] In Embodiment 1, 1000
Needle punching was performed at P / cm ² to prepare an entangled nonwoven fabric. The density of the obtained nonwoven fabric was 0.45 g / cm ³ . Further, the same operation as in Example 1 was performed to produce an artificial leather. The obtained artificial leather was soft and excellent in anti-stretch feeling.

Comparative Example 1 Nylon 6 and polyethylene chips were melt spun at a ratio of 50:50, applied with an oil agent, stretched, crimped, and cut to obtain a mixed spun raw cotton of 8 de × 51 mm. The crimp degree of the obtained fiber was 15%. This was placed on a roller card, laminated with a cross layer, and needle-punched at 1000 P / cm ² to produce an entangled nonwoven fabric. The density of the obtained nonwoven fabric was 0.18 g / cm ³ . Next, this non-woven fabric is
After heating at 0 ° C, the mixture was impregnated with a 12% polyurethane solution, wet-coagulated, dried, and then extracted with 80 ° C toluene. The obtained artificial leather was soft, but poor in elongation.

[Comparative Example 2] After melt-spinning nylon 6 and polyethylene chips at a ratio of 50:50, the chips were picked up by an ejector, applied with an oil agent, crimped, and then deposited on a moving collecting surface. To produce a web. The degree of crimp of the fibers in this web was 15%. Then 1000P / cm
Needle punching was performed in ² to produce an entangled nonwoven fabric. The density of the obtained nonwoven fabric was 0.22 g / cm ³ . Next, this nonwoven fabric was heated at 150 ° C., then impregnated with a 12% strength polyurethane solution, wet coagulated, dried, and then dried at 80 ° C.
The polyethylene was extracted with toluene. The obtained artificial leather was soft, but poor in elongation.

Comparative Example 3 In Example 1, 2000
Needle punching was performed at P / cm ² to prepare an entangled nonwoven fabric. The density of the obtained nonwoven fabric was 0.51 P / cm ² . Further, the same operation as in Example 1 was performed to produce an artificial leather. In the obtained artificial leather, extraction of polyethylene was difficult, and it had a hard texture.

[0028]

According to the present invention, defects of the base fabric between the conventional artificial leathers using crimped short fibers can be eliminated at a stroke. In other words, the complicated and irrational card process for obtaining the base cloth is completely omitted, and the high density, which could not be expected with crimped short fibers, is realized, and the base cloth with a soft feeling is realized. From this base fabric, an artificial leather having an unprecedented softness and improved stretchability is provided.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI D06M 15/564 D06M 15/564 D06N 3/00 DAA D06N 3/00 DAA

Claims (3)

[Claims] 1. A base fabric for artificial leather, wherein the nonwoven fabric satisfies the following requirements (A) to (C): (A) The degree of crimp of the long fibers constituting the nonwoven fabric is 10% or less. (B) The long fibers constituting the nonwoven fabric can generate ultrafine fibers of 0.5 de or less. (C) The fiber density of the nonwoven fabric is 0.25 to 0.50 g / cm
^{Being 3} 2. The long fiber constituting the nonwoven fabric is represented by the following (1):
The artificial leather base fabric according to claim 1, comprising a combination of any one of the polymers (1) to (3). (1) polyamide polymer and polyolefin polymer; (2) polyester polymer and polyolefin polymer; or (3) polyamide polymer and polyester polymer; 3. A step of impregnating the base cloth for artificial leather according to claim 1 or 2 with a polymer elastic body solution and then solidifying the elastic body in water, and forming the base cloth before and after the step. A process for producing engineered leather that is flexible and has an improved anti-stretch feeling, comprising the step of generating ultrafine fibers of 0.5 de or less from long fibers and performing ultrafine treatment.