JPH05239752A - Acrylic fiber nonwoven fabric and production thereof - Google Patents

Abstract

PURPOSE:To provide nonwoven fabrics having a touch like woven or knit fabrics as well as a new design pattern. CONSTITUTION:The objective acrylic fiber nonwoven fabrics are obtained by bonding a layer of the acrylic fibers (fiber 1) where their cross sections include a plurality of unspecifically shaped openings inside, the openings extend almost in parallel with the lengthwise direction at least 60mum long to form linear spaces, and at least a part of the fibers are split into microfine fibers integrally to another layer of acrylic fibers other than the fiber 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel non-woven fabric made of acrylic fiber as a raw material and a method for producing the same.

[0002]

2. Description of the Related Art Nonwoven fabrics made from acrylic fibers have been hitherto known, but recently, nonwoven fabrics made of acrylic fibers having a special fiber structure (Japanese Unexamined Patent Publication No. Heisei 2-200857).
Japanese Patent Laid-Open No. 2-242956) has been receiving attention. Japanese Patent Application Laid-Open No. 2-200857 has a large number of openings having an unspecified shape in a cross section of a fiber, and each of the openings has an inner diameter of 60 μm which is substantially parallel to the length direction of the fiber. A non-woven fabric made of acrylic fibers having streaky (straw-like) voids having the above length is disclosed in JP-A-2-242956 and a fiber layer made of the fibers and polyester fibers, cellulosic fibers or A laminated non-woven fabric in which a fiber layer made of heat resistant fibers such as wool is integrally bonded is disclosed.

[0003]

There is a demand for a non-woven fabric having novel characteristics due to diversification of consumption trends, and although the conventional non-woven fabric has a soft feel and texture, it is a woven or knitted fabric. It is not suitable for general clothing except the special clothing field, not the feel and texture of such cloth.

An object of the present invention is to provide a non-woven fabric which has different textures on the front and back sides and at the same time has the feel and texture of a woven or knitted fabric, and a method for producing the same.

[0005]

The present invention is as follows. The fiber has a large number of openings having an unspecified shape in its cross section, and each of the openings has a stripe-shaped void having a length of 60 μ or more which is substantially parallel to the inside of the fiber along the length direction of the fiber. A fiber layer in which at least a part of the acrylic fiber (fiber 1) forming the fiber is divided into fine fibers and a fiber layer made of acrylic fiber (fiber 2) other than the fiber 1 are integrally bonded. 2. Acrylic fiber non-woven fabric (claim 1), The fiber has a large number of openings having an unspecified shape in its cross section, and each of the openings has a stripe-shaped void having a length of 60 μ or more which is substantially parallel to the inside of the fiber along the length direction of the fiber. A fiber layer made of an acrylic fiber (hereinafter referred to as fiber 1) forming a layer and a fiber layer made of an acrylic fiber other than fiber 1 (hereinafter referred to as fiber 2) are overlapped,
Next, high-pressure water is sprayed from the nozzle onto the fiber layer, which is a method for producing an acrylic fiber nonwoven fabric (claim 2).

The acrylic fiber nonwoven fabric of the present invention and the method for producing the same will be described in more detail below. Description of Fiber 1 FIG. 1 shows a fiber 1 forming the acrylic fiber nonwoven fabric of the present invention.
FIG. 2 is an electron micrograph (4,000 times) of the cross section of (Example 1) and FIG. 2 is the cross section of the same fiber.

In FIGS. 1 and 2, black portions are voids. As can be seen from FIG. 1, the fiber 1 has a large number of openings of unspecified shape in its cross section. The large number of irregularly shaped openings present in the cross section of the fiber allows the fiber 1 to be easily split (teared) along the length of the fiber. The size of the opening (pore diameter) is not particularly limited as long as the conditions described below are satisfied. A large number of fine openings is preferable from the viewpoint of easy fiber division and fine tear fibers. Further, even if there is an opening having a large pore size, the fiber is easily divided if there is an opening having a small pore size around the opening.

As shown in FIG. 2, each of the openings forms a stripe-shaped (straw-shaped) void inside the fiber which is substantially parallel to the length direction of the fiber. The length of the void along the length direction of the fiber (hereinafter, referred to as length) must be long enough to easily divide the fiber. From this viewpoint, the length of the void is preferably 60 μm or more, and if it is shorter than this, it becomes difficult to divide the fiber in the longitudinal direction. When the length of the voids is 60 μm or more, the longer the length, the easier the fiber division becomes, and it is most preferable that the voids are substantially continuous over the entire length.

The number of openings in the cross section of the fiber must be large enough to allow the fiber to be easily divided, but it is not uniformly determined in relation to the length of the voids in this opening, but 1
There must be at least 00. If it is less than this, it becomes difficult to divide the fibers even if the voids are continuous pores of 60 μ or more. This void is 100 in the cross section of the fiber.
If there are more than one fibers, the more fibers are present, the more easily the fibers are divided, and the finer fibers are also easily formed. Further, it is preferable that the voids are evenly distributed in the cross section of the fiber in order to facilitate the division of the fiber.

This fiber is easily divided into fine fibers by columnar flow punching of high-pressure water in the step of producing a nonwoven fabric, and a fiber layer made of fine fibers is formed on one surface of the nonwoven fabric. The fine fibers obtained by dividing the fiber 1 are the fibers 2
Therefore, when the non-woven fabric is dyed, there is a change in the shade of the color and the shade on the front and back sides of the nonwoven fabric, which is effective for visual appearance.

Description of Fiber 2 The fiber 2 is an acrylic fiber other than the fiber 1 and is not particularly limited, but its fineness is 0.5 denier or more, 1
It is preferably 0 denier or less. When it is less than 0.5 denier, the feel and feel of the nonwoven fabric are not significantly different from that of the fiber layer made of the fiber 1, and when it exceeds 10 denier, the feel is hard, which is not preferable. Especially as fineness 1-3
Denier is preferred.

The fiber 2 has a different feeling and texture on the front and back of the non-woven fabric in relation to the fiber 1.
It is a fiber necessary to give a soft texture to the entire nonwoven fabric. This fiber 2 has a different feeling and texture from the fine fibers obtained by dividing the fiber 1. For this reason, a texture and a feeling different from those of the fiber layer composed of the divided fine fibers of the fiber 1 are exhibited. Description of Structure of Nonwoven Fabric FIG. 3 is an electron micrograph (119) showing the shape of the surface of the nonwoven fabric of the present invention (Example 1) as seen from the fiber 1 fiber layer side.
2 times), and the fibers 1 are divided into fine fibers and dispersed irregularly, and the divided fine fibers are entangled with each other. The fibers 1 are divided into fine fibers, but individual fine fibers You can see the parts that are aggregated into a bundle. These portions are irregularly distributed, and the fibers are entangled with each other and integrated to form a fiber layer on the surface of the nonwoven fabric.

FIG. 4 is also an electron micrograph (83 times) showing the shape of the cross section thereof, and the upper side is a fiber layer composed of fine fibers obtained by dividing the fiber 1. The lower side thereof is a fiber layer composed of fibers 2, and at the boundary portion between the both fiber layers, fine fibers obtained by dividing the fiber 1 are obtained, fibers that are divided but fine fibers are bundled, or undivided. Fibers such as fiber 1 and fiber 2 are intertwined with each other and integrated. Further, it can be seen that some of the fine fibers divided by the fiber 1 penetrate the layer of the fiber 2 and reach the surface of the fiber layer made of the fiber 2.

Similarly, FIG. 5 is an electron micrograph (118 times) showing the shape of the surface of the fiber 2 as seen from the fiber layer side. The fiber 2 is entangled to form the other fiber layer of the nonwoven fabric. Thus, some of the fine fibers obtained by dividing the fiber 1 penetrate the layer of the fiber 2 and reach the surface of the fiber layer made of the fiber 2. The entanglement of the fine fibers obtained by dividing the fibers 1 and the entanglement of the fibers 2 with each other gives practically sufficient tensile strength and tear strength to the non-woven fabric, and also gives the non-woven fabric a soft feel and texture possessed by the woven or knitted fabric. .. This effect is a major feature of the present invention and is not found in conventional nonwoven fabrics.

The division of the fiber 1 and the entanglement with the fiber 2 are performed by columnar flow punching of high pressure water. When the columnar flow punching process is performed from the side of the fiber layer composed of the fibers 1, the fine fibers obtained by dividing the fibers 1 enter into the fiber layer formed by the fibers 2 and the fibers are entangled with each other, and at the same time, the divided fine fibers are obtained. Mutual confounding takes place. in this case,
At the boundary between the fiber layers of the fiber 1 and the fiber 2, there is a part of the fiber 1 which is not divided or a bundle of fine fibers which are divided but not dispersed.

After that, a columnar flow punching process may be performed from the side of the fiber layer composed of the fibers 2. By this treatment, the fibers 2 enter the fiber layer made of the fibers 1, and the fibers are entangled with each other more strongly. In this example, the nonwoven fabric has a structure in which two layers of a fiber layer composed of the fiber 1 and the fiber 2 are laminated, but a nonwoven fabric having a three-layer structure in which a fiber layer composed of the fiber 2 is laminated with a fiber layer composed of the fiber 2 sandwiched therebetween. good.

In the nonwoven fabric of the present invention, one surface of the nonwoven fabric is mainly covered with fine fibers obtained by dividing the fibers 1, and the other surface of the nonwoven fabric is mainly covered with fibers 2. However, the fibers 2 enter into the fiber layer composed of the divided fine fibers of the fibers 1 and these fibers are entangled with each other,
On the other hand, the fine fiber obtained by dividing the fiber 1 enters the fiber layer formed of the fibers 2 and these fibers are entangled with each other.
The characteristics of the fibers 1 and 2 constituting the non-woven fabric and the structure of the mixed entanglement of these fibers interact with each other, and the surface of the non-woven fabric mainly composed of the fibers 2 exhibits a velvet-like soft and smooth texture and feel. To do.

This characteristic can be realized for the first time by the present invention and is a characteristic which is not present in the conventional nonwoven fabric. Further, the fine fibers obtained by dividing the fibers 1 and the fibers 2 have different dyeing properties, and can be dyed in different colors on the front and back sides, and a non-woven fabric having a different design and different design can be obtained.

The fibers 1 and 2 of the present invention are fibers made of an acrylic polymer, and this polymer represents 60% by weight of acrylonitrile (hereinafter abbreviated as AN) (hereinafter,% means% by weight unless otherwise specified). ) A polymer containing the above. A
When the N content is less than 60%, the acrylic fiber originally has softness and loses a wool-like feel, which is not preferable. The polymer may be a mixture of two or more acrylic polymers.

Manufacturing Method of Fiber 1 The acrylic polymer is dissolved in a solvent thereof, for example, dimethylformamide, dimethylacetamide, dimethylsulfoxide, concentrated aqueous solution of rhodanate, concentrated aqueous solution of zinc chloride and aqueous solution of nitric acid to prepare a spinning dope. Although the optimum polymer concentration varies depending on the solvent, it is preferably about 10 to 30%.

By adding polyalkylene glycol to this spinning solution, fibers having continuous voids in the length direction of the fibers can be obtained. This polyalkylene glycol is a random type or block type copolymer of ethylene oxide 20 to 80% and propylene oxide 80 to 20%, and its number average molecular weight is 5,000 to 50,000.
It is 0, preferably 10,000 to 20,000.

When the number average molecular weight of the polyalkylene glycol is less than 5,000, continuous voids cannot be obtained in the lengthwise direction of the fiber, and the fiber becomes a microporous fiber having extremely fine substantially spherical cavities. On the other hand, the number average molecular weight is 5
When it exceeds 10,000, the fiber has a huge streak-like hollow portion, and moreover, the fiber has at most a dozen or more hollow portions in the cross section of the fiber. This fiber cannot be divided into fine fibers by an external force such as columnar flow punching. A polyalkylene glycol having a number average molecular weight of 10,000 to 20,000 is fine along the length direction of the fiber, and a fiber having an elongated void with an unspecified cross-sectional shape in its cross section can be obtained.

The spinning solution containing the polyalkylene glycol is then aged for at least 4 hours. This ripening is to leave the spinning dope containing polyalkylene glycol added, without vigorously stirring or vibrating, for example, to leave still or to gently feed the solution. The amount of polyalkylene glycol added is 5 to 20%, preferably 10 to 15%, based on the acrylic polymer. If the addition amount is less than 5%, the voids in the cross section of the fiber will be small, and if it exceeds 20%, the voids will be too large, and the fibers will be divided during the manufacturing process of the fiber, and stable spinning will not be possible. Cause When the added amount is 10 to 15%, the number of voids in the cross section of the fiber, the stability of spinning and the like are most balanced.

The stock solution for spinning containing polyalkylene glycol is extruded into the coagulating liquid through a spinneret,
After undergoing steps such as washing with water, stretching and drying, heat treatment is carried out if necessary. The polyalkylene glycol added to the spinning dope is eluted from the coagulated filamentous material in the steps such as coagulation, stretching and washing with water. Nonwoven Fabric Manufacturing Method The long fibers or short fibers of the fiber 1 and the fiber 2 are formed into a fiber layer by a web forming apparatus which has been conventionally used for manufacturing a nonwoven fabric.

In the case of short fibers, ordinary carded, woolen cards and random cards may be used, and an air-laid method using turbulent air flow, a paper-making method using water dispersion, etc. may be used. Next, the fiber layer of the fiber 1 and the fiber layer of the fiber 2 are laminated, the laminated fiber layer is supported on a net or a roller, and high-pressure water is sprayed from the fiber layer side composed of the fiber 1. By this treatment, the fibers 1 are divided into fine fibers and dispersed irregularly, the portions where the fine fibers are entangled with each other, the portions where the fine fibers are gathered into a bundle, and further, These fibers form a portion in which the fibers 2 are entangled with each other, and as a whole, a non-woven fabric in which all the fibers are integrally bonded is formed.

The columnar flow punching of the high-pressure water can also be performed from the fiber layer side of the fiber 2. In this case, the entanglement of the fibers is performed more strongly, the tensile strength of the nonwoven fabric,
Physical properties such as tear strength are improved. This columnar flow punching process is performed from the fiber layer side of the fiber 2 and then the fiber 1
It may be performed from the fiber layer side.

The high-pressure water column flow punching process is carried out once or more depending on the entangled condition of the fibers or the divided condition of the fibers 1. The more this treatment is, the more the fibers 1 are divided and the fibers are entangled with each other. The high-pressure water requires a pressure of 10 kg / cm ² or more, and if the pressure is lower than this, it becomes difficult to divide the fiber 1 and at the same time, the entanglement between the fibers is reduced.

The nozzle for injecting high-pressure water is appropriately selected according to the target surface morphology of the nonwoven fabric and the divided state of the fiber 1. The diameter of this nozzle is small, and the lower the water pressure, the fiber 1
Splitting occurs in the surface layer portion of the layer of the fiber 1, and the higher the water pressure, the more the splitting of the fiber 1 and the mutual interaction of the fibers to the inside. The texture, feel, etc. of the nonwoven fabric can be adjusted by appropriately adjusting the conditions of this treatment.

When the fibers 1 are excessively divided and the fibers are entangled excessively, the texture and feel of the nonwoven fabric tend to be paper-like, and when it is loosened, the nonwoven fabric has a soft texture. After performing the high-pressure water column flow punching treatment, the nonwoven fabric is dried. This dryer is a dryer such as a pin tenter dryer or a drum dryer. The basis weight of the fiber layer of the fiber 1 and the fiber 2 is
Each is 5 g / m ² or more, preferably 20 g / m ² or more. If the basis weight is less than 5 g / m ^2, it is difficult to manufacture a uniform nonwoven fabric.

The non-woven fabric produced in this manner has the feel and feel of a woven or knitted fabric, and the surface composed mainly of the fibers 2 has a high-grade velvety feel and feel. Further, excellent designability is exhibited due to the different dyeability on the front and back of the nonwoven fabric. This characteristic is exhibited by the combination of the fiber 1 and the fiber 2, and is completely different from the paper-like feel and texture that the conventional non-woven fabrics have. I was able to give the texture and feel of the knitted fabric.

The conventional nonwoven fabric is unsuitable as a clothing except for special clothing because of the texture of paper, but the nonwoven fabric of the present invention can be generally applied to clothing.
Further, as a feature of the present invention, by impregnating the above nonwoven fabric with an elastic polymer, a leather-like cloth having a high-quality natural leather-like feel and texture can be obtained. For the impregnation of the elastic polymer into the nonwoven fabric, a conventionally known method can be applied. The general method is to impregnate the non-woven fabric with a solvent of an acrylic fiber and a solvent of an elastic polymer, and then impregnate it with an elastic polymer solution, preferably a polyurethane solution, which is then placed in a coagulating liquid such as water. It is a method of dipping to solidify the elastic polymer.

The solvent which is a non-solvent for the acrylic fiber and acts as a solvent on the elastic polymer is toluene, xylene, benzene, ethyl acetate, acetone, methyl ethyl ketone, cyclohexanone or the like. Polyurethane is preferred as the elastic polymer.

[0033]

EXAMPLES The present invention will be specifically described below with reference to examples.

[0034]

Example 1 AN 95.0%, methyl acrylate 4.5
% And copolymer of 0.5% sodium methallyl sulfonate,
Polyethylene oxide-polypropylene oxide-polyethylene oxide block type polyether (number average molecular weight 10,000, polyethylene oxide / polyethylene oxide ratio 70:30) is dissolved in dimethylformamide to give an acrylic polymer 23%, block type. A spinning dope containing 2.3% polyether was prepared.

After leaving this spinning dope for 6 hours, it was extruded through a spinneret into a coagulation bath containing dimethylformamide at 75% at a temperature of 35 ° C., washed with water, stretched 12 times in boiling water, and dried in hot air at 80 ° C. Then, a fiber having a denier of 1.5 (fiber 1) was produced. 1 and 2 are electron micrographs (× 4000) showing the shapes of the cross section and the vertical section of this fiber.
Shown in.

After the fibers were cut, a card was used to produce a fiber layer having a basis weight of 35 g / m ² . Apart from this, 1.
A commercially available acrylic fiber (fiber 2) of 5 denier was similarly produced into a fiber layer having a basis weight of 35 g / m ² , and these two fiber layers were laminated and placed on a 100 mesh wire mesh to form a layer of fiber 1. From the side of 0.1 mm, pitch 0.8 mm 1
Water is jetted from the row nozzle at a water pressure of 60 kg / cm ² and 4
Processing was performed while moving at a speed of m / min. Next, under the same conditions, high-pressure water was jetted from the layer 2 side of the fiber 2 for treatment. This operation was repeated 10 times on the fiber laminate consisting of the fibers 1 and 2, and then dried in hot air at 80 ° C.

FIG. 3 is an electron micrograph (119 times) showing the shape of the surface of the obtained non-woven fabric as seen from the side of the fiber layer composed of the fiber 1. The fiber 1 is irregularly divided into fine fibers. It can be seen that there are parts in which the fine fibers are dispersed and are entangled with each other, and the fine fibers are divided into fine fibers, but individual fine fibers are aggregated into a bundle. These portions are irregularly distributed, and the fibers are entangled with each other and integrated to form a fiber layer on the surface of the nonwoven fabric.

FIG. 4 is an electron micrograph (83 times) showing the shape of the cross section of the nonwoven fabric, and the upper side is a fiber layer composed of fine fibers obtained by dividing the fiber 1. The lower side is a fiber layer composed of fibers 2, and at the boundary portion of both fiber layers, fiber 1
The divided fine fibers, the divided fine fibers are bundled, or the undivided fibers 1 and 2 are intertwined and integrated with each other. Further, some of the fine fibers divided by the fibers 1 penetrate the layer of the fibers 2 and reach the surface of the fiber layer formed of the fibers 2.

FIG. 5 is an electron micrograph (118 times) showing the shape of the surface of the fiber 2 as viewed from the side of the fiber layer, in which the fibers 2 are entangled to form the other fiber layer of the nonwoven fabric. A part of the divided fine fibers of the fiber 1 penetrates the layer of the fiber 2 and reaches the surface of the fiber layer composed of the fiber 2. The obtained non-woven fabric had the feel and feel of a woven fabric. In particular, the surface of the fiber layer side composed of the fibers 2 had a high-grade velvet-like texture, and there was no paper-like feel found in conventional nonwoven fabrics.

When this non-woven fabric was dyed, the divided fine fiber layer was dyed in a light color, while the layer composed of the fibers 2 was dyed in a dark color, and a highly designed non-woven fabric having different tone on the front and back sides was obtained. ..

[0041]

Example 2 AN 90.0%, methyl acrylate 9.5
% And copolymer of 0.5% sodium methallyl sulfonate,
Random copolymerization type polyether of ethylene oxide and propylene oxide (number average molecular weight 10,000, the ratio of ethylene oxide and ethylene oxide is 75:25)
Is dissolved in a 67% aqueous nitric acid solution to give an acrylic polymer 16
%, And a random copolymerization type polyether 2.4% was prepared.

After this spinning dope was allowed to stand for 4 hours, it was extruded through a spinneret into a 37% nitric acid aqueous solution cooled to 0 ° C., washed with water, stretched 9.5 times in boiling water, and heated in 70 ° C. hot air. It was dried to produce 1.5 denier fiber (fiber 1). After cutting this fiber, use a card to give a basis weight of 40
A fiber layer of g / m ² was produced. Separately from this, a commercially available acrylic fiber having a denier of 1.5 (fiber 2) was produced in the same manner to form a fiber layer having a basis weight of 45 g / m ² . The two fiber layers are laminated and placed on a 100 mesh wire mesh to
From the layer side, water is jetted at a water pressure of 60 kg / cm ² from a one-row nozzle having a diameter of 0.1 mm and a pitch of 0.8 mm, and 4 m
Processing was performed while moving at a speed of / minute. Next, under the same conditions, high-pressure water was jetted from the layer 2 side of the fiber 2 for treatment.

This operation was repeated 10 times on the laminate of fibers consisting of the above fibers 1 and 2 and then dried in hot air at 80 ° C. The obtained non-woven fabric had the same feel and texture as the non-woven fabric obtained in Example 1, and had no paper-like feel at all. The surface of the fiber 2 on the fiber layer side had a high-grade velvet-like texture. In addition, the dyed nonwoven fabric is
Similar to Example 1, the nonwoven fabric was highly aesthetic and had different colors on the front and back.

[0044]

Example 3 After cutting the fiber 1 produced in Example 1, a fiber layer having a basis weight of 40 g / m ² was produced using a card.
Separately from this, a commercially available acrylic fiber (fiber 2) having a denier of 0.6 was similarly prepared to produce a fiber layer having a basis weight of 30 g / m ² . The two fiber layers are laminated and placed on a 100-mesh wire net, and the diameter of the fiber 1 is 0.1 mm from the layer side.
Water was jetted at a water pressure of 60 kg / cm ² from a one-row nozzle having a pitch of 0.8 mm and treated while moving at a speed of 4 m / min. Next, under the same conditions, high-pressure water was jetted from the layer 2 side of the fiber 2 for treatment. This operation was repeated 5 times on the laminate of fibers consisting of the above fibers 1 and 2, and then dried in hot air at 80 ° C.

The non-woven fabric obtained was similar to the non-woven fabric of Example 1 in structure, feel and texture. In addition, when this non-woven fabric is dyed, the finely divided fiber layers are light colored,
On the other hand, the layer made of the fiber 2 was a highly-dyed non-woven fabric which was dyed in a dark color and had different color tones on the front and back sides.

[0046]

Example 4 The non-woven fabric obtained in Example 1 was impregnated with methyl ethyl ketone, impregnated with a dimethylformamide solution containing 30% of polyurethane, and then coagulated in water.
After thoroughly washing dimethylformamide, it was dried with hot air at 80 ° C. to produce a nonwoven fabric containing 10% of polyurethane. The surface of this non-woven fabric was polished with emery paper to produce a suede-like artificial leather having naps.

This artificial leather was extremely soft and had a smooth surface feel.

[0048]

The non-woven fabric of the present invention is a novel non-woven fabric having a woven or knit-like feel and texture. This feel and texture are completely different from the paper-like feel and texture of conventional non-woven fabrics, and open up new applications of non-woven fabrics as well as general fabrics for clothing.

This non-woven fabric has different dyeing properties on the front and back sides, and when dyed, it gives a non-woven fabric with high designability.

[Brief description of drawings]

FIG. 1 is a cross section of a fiber 1 forming an acrylic fiber nonwoven fabric of the present invention.

FIG. 2 is an electron micrograph of the shape of the longitudinal section of the fiber 1 (4,
000 times).

FIG. 3 is an electron micrograph (119 times) showing the shape of the surface of the nonwoven fabric of the present invention as seen from the side of the fiber layer made of fibers 1.

FIG. 4 is an electron micrograph (83 times) showing the shape of a cross section of a nonwoven fabric.

FIG. 5 is an electron micrograph (× 118) showing the shape of the surface viewed from the side of the fiber layer made of the fiber 2.

Claims (2)

[Claims] 1. The fiber has a large number of openings having an unspecified shape in its cross section, and each of the openings has a length of 60 μ or more which is substantially parallel to the inside of the fiber along the length direction of the fiber. A fiber layer in which at least a part of the acrylic fiber (fiber 1) forming the streak-like voids is divided into fine fibers, and a fiber layer made of an acrylic fiber (fiber 2) other than the fiber 1 Acrylic fiber non-woven fabric that is integrally bonded. 2. The fiber has a large number of openings having an unspecified shape in its cross section, and each of the openings has a length of 60 μ or more which is substantially parallel to the inside of the fiber along the length direction of the fiber. The fiber layer made of acrylic fiber (fiber 1) forming the streak-like voids and the fiber layer made of acrylic fiber (fiber 2) other than fiber 1 are superposed, and then high-pressure water is applied to the fiber layer. A method for producing an acrylic fiber non-woven fabric, which comprises spraying from a nozzle.