JPH10266052A - Nonwoven fabric and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nonwoven fabric having low surface friction resistance and excellent feeling, filtering performance and surface durability and useful as a base for artificial leather, etc., by forming a laminate in such a manner as to form the surface with a fiber web containing a physically splittable fiber and treating the laminate under specific condition. SOLUTION: Two or more fiber webs consisting of a fiber web composed mainly of an elimination-type splittable fiber and a fiber web composed of a physically splittable fiber are laminated one upon another in such a manner as to form a surface with the fiber web containing the physically splittable fiber. The laminated fiber web is subjected to a fluid flow treatment to effect the splitting of the physically splittable fiber to produce ultrafine fibers B which are entangled with each other to form an interlocked fiber web. One or more resin components X, Y of the elimination-type splittable fiber are removed to produce ultrafine fibers A and form an entangled fiber web, which is again subjected to fluid flow treatment to obtain the objective nonwoven fabric.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a nonwoven fabric and a method for producing the same.

[0002]

2. Description of the Related Art A resin component (island component) which is hardly soluble in a solvent capable of dissolving and removing the resin component in one resin component (sea component).
A so-called sea-island type fiber in which is dispersed in an island shape is known. After forming a fiber web containing this sea-island type fiber, and entangled, the sea component of the sea-island type fiber is dissolved and removed to form an island component. Nonwoven fabrics that have produced ultrafine fibers consisting of Since this nonwoven fabric contains ultrafine fibers, it is excellent in feeling and filtration performance, and it is highly useful because artificial leather can be formed by impregnating with a urethane resin. By the same method, in order to produce a nonwoven fabric having a better feeling and filtration performance, when ultrafine fibers having an average fiber diameter of 1 μm or less are generated, the surface friction resistance becomes high,
In some cases, the intended use was limited. Therefore, non-woven fabrics with excellent feel and filtration performance, and low surface friction resistance,
The present applicant has proposed in Japanese Patent Application No. 8-103187.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a nonwoven fabric which is excellent not only in feeling and filtration performance, but also has low surface friction resistance and excellent surface resistance, and a process for producing the same.

[0004]

According to the present invention, there is provided a nonwoven fabric comprising ultrafine fibers generated from a releasable splittable fiber capable of removing one or more resin components to generate ultrafine fibers having an average fiber diameter of 1 μm or less. And an entangled layer containing microfibers B generated from physically splittable fibers capable of generating microfibers B by being split by a physical action on at least one surface. As described above, since the layer mainly including the fine fibers A having an average fiber diameter of 1 μm or less is included, the fine fibers B generated from the physically splittable fibers capable of generating the fine fibers B are excellent in feeling and filtration performance. Since at least one surface has the entangled layer containing at least one surface, the surface friction resistance of at least one surface is low, and furthermore, both the layer mainly composed of the microfine fibers A and the layer containing the microfine fibers B are entangled. Excellent resistance.

In the method for producing a nonwoven fabric according to the present invention, at least two fiber webs, ie, a fiber web mainly composed of removable splittable fibers and a fiber web containing physically splittable fibers, are made to contain physically splittable fibers. Laminating the fiber web so as to form at least one surface, applying a fluid flow to the laminated fiber web to divide the physically splittable fibers to generate microfibers B and to entangle them. A step of forming a conjugate fiber web, a step of removing one or more resin components of the removable splittable fiber to generate ultrafine fibers A, and forming a removed entangled fiber web, and a removed entangled fiber web Forming a non-woven fabric by applying a fluid flow again to the non-woven fabric. Therefore, it is a method that can easily produce the nonwoven fabric of the present invention.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The nonwoven fabric of the present invention is mainly composed of ultrafine fibers A generated from a releasable splittable fiber capable of removing one or more resin components to generate ultrafine fibers A having an average fiber diameter of 1 μm or less. It has excellent feeling and filtration performance. Extra fine fiber A for better feeling
Is more preferably 0.7 μm or less. The average fiber diameter of the ultrafine fibers A is preferably 0.01 μm or more so that the fibers do not easily fall off.

In the present invention, when the fiber has an irregular cross-sectional shape, the diameter of a circle having the same cross-sectional area as the cross-sectional area of the irregular cross-section is defined as the fiber diameter of the fiber, and 50 randomly selected fibers are used. The average value of the fibers is called the average fiber diameter.

As the removable splittable fiber, for example,
As shown in the fiber cross-sectional schematic diagram in FIG. 1, a sea-island type fiber in which a hard-to-removal Y component is arranged and / or dispersed in an island-like manner in the X component removable by the remover in the X component is shown. In addition, by removing the X component of the sea-island type fiber, it is possible to generate the ultrafine fiber A composed of the Y component.

[0009] As the removing agent capable of removing one or more resin components of the removable splittable fiber, there are, for example, a solvent, an enzyme and a microorganism. Among these, the solvent is preferred because the removal rate is high and the handling is easy. Can be used for Among these solvents, aqueous solvents can be suitably used because they are easy to handle and process. In the present invention, "removable" means that 95% by mass or more of the resin component can be removed, and "removability" means that only 5% by mass or less of the resin component is removed under the conditions for removing the resin component.

[0010] As another removable splittable fiber, as shown in a schematic cross-sectional view of the fiber in Fig. 2, an X component which can be removed by a remover and a Y component which is difficult to remove or a Y component which is hardly removed are used. There is a multi-bimetallic fiber in which a Y component that can be removed with an agent and an X component that is difficult to remove as a Y component removing agent are alternately layered in layers, and the X component or Y component of the multi-bimetallic fiber is removed. Thereby, it is possible to mainly generate the ultrafine fibers A having a substantially trapezoidal cross-sectional shape made of the Y component or the X component.

FIG. 3 shows another removable splittable fiber.
(A) and (b), as shown in the schematic cross-sectional view of the fiber, the X component that can be removed by the remover is removed by the remover of the X component by the Y component that is difficult to remove, or the remover of the Y component is difficult to remove by the remover. There is a chrysanthemum-shaped fiber in which the X component is extended from the interior of the fiber (preferably the fiber axis) to the fiber surface by the Y component capable of removing the sex X component with the removing agent, and the X component is divided. By removing the Y component, it is possible to generate an ultrafine fiber A composed of the Y component or the X component and having a U-shaped or fan-shaped cross-sectional shape.

In each case, the case where the removable splittable fiber is composed of two kinds of resin components has been described.
It may be composed of more than three types of resin components, and if it is composed of three types of resin components, two or less types of ultrafine fibers A can be generated. Can occur.

[0013] When the removable splittable fiber is composed of three or more resin components, for example, at least one island component of the sea-island type fiber is a sea-island type, a multiple bimetal type, a chrysanthemum type,
A core-sheath type, an eccentric type, or a side-by-side type, wherein at least one resin component unit (X component or Y component in FIG. 2) of the multi-bimetal type fiber is a sea-island type, a multi-bimetal type, a chrysanthemum type, A core-sheath type, an eccentric type, or a side-by-side type, at least one resin component unit (X component or Y component in FIG. 3) of chrysanthemum flower fiber is a sea-island type;
Examples include a multi-bimetal type, a chrysanthemum type, a core-sheath type, an eccentric type, and a side-by-side type. By using such removable splittable fibers, finer ultrafine fibers A can be generated, so that a nonwoven fabric having a better feeling can be formed. If the ultrafine fibers A can be fused, a nonwoven fabric having excellent shape stability can be formed by fusion. Furthermore, if the microfiber A is composed of two or more types of resin components, and a crimp can be expressed by utilizing the difference in shrinkage of the resin components, a nonwoven fabric having a better feeling or a nonwoven fabric having an excellent elasticity can be formed. it can.

Among the above-mentioned removable splittable fibers,
Sea-island type fibers and removable splittable fibers having a sea-island type resin component unit in the fiber cross section can be suitably used because they tend to generate ultrafine fibers A having an average fiber diameter of 1 μm or less.

The ultrafine fibers A that can be generated from such removable splittable fibers do not need to have a single fiber diameter, and may have various fiber diameters. It is necessary that the average fiber diameter be 1 μm or less so as not to impair. The number of microfibers A that can be generated from one removable splittable fiber is not particularly limited, but is 3 to 1
About 5,000 are suitable. Further, ultrafine fibers A having different fiber cross-sectional shapes may be mixed.

Examples of the resin component constituting the removable splittable fiber include polyamides such as nylon 6, nylon 66, and nylon copolymer, polyethylene terephthalate, polyethylene terephthalate copolymer, and the like, which are capable of forming fibers. Polybutylene terephthalate, polyester such as polybutylene terephthalate copolymer, polyethylene, polypropylene, polyolefins such as polymethylpentene, polyurethane, polyacrylonitrile, vinyl polymers such as polystyrene, or polyglycolic acid, glycolic acid copolymer, Aliphatic polyester polymers such as polylactic acid and lactic acid copolymers, and capramid, tetramethylene adipamide, undecanamide, laurolactamide, hexamethylene adipamide Among aliphatic polyester amide copolymers obtained by copolymerizing aliphatic amides and the like, for a certain removing agent, a combination of a removable resin and a hard-to-removable resin so as to include at least one resin. Just do it. For example, when one type of removable resin and one type of hard-to-removable resin are included, the removable polystyrene and the hard-to-removable polyamide and the remover for toluene and the remover for perclene are removable. There are combinations of polyethylene, hard-removable polyamides, and removers of alkaline aqueous solutions, such as removable polyesters and hard-removable polyolefins. Among these, a combination of a polyester and a polyolefin (particularly, polypropylene) is preferable because an alkaline aqueous solution is easy to handle as a remover.

On the other hand, at least one surface has an entangled layer containing ultrafine fibers B and / or ultrafine fibers B 'generated from physically splittable fibers capable of splitting by physical action to generate ultrafine fibers B. Thereby, a layer having low surface friction resistance is formed without impairing characteristics such as feeling and filtering performance of the ultrafine fibers A generated from the removable splittable fibers.
Therefore, when it is preferable that both surfaces have low frictional resistance, both surface layers are formed as entangled layers containing the ultrafine fibers B and / or the ultrafine fibers B ′.

The physically splittable fibers include, for example,
As shown in the schematic cross-sectional view of the fiber in FIG. 1, among the X components that can be divided by a physical action, there is a sea-island type fiber in which a Y component poorly compatible with the X component is arranged and / or dispersed in an island shape. By dividing the sea-island type fiber, the ultrafine fiber B ₁ composed of the X component, the ultrafine fiber B ₂ composed of the Y component, and the X component and the Y
The microfine fibers B ₃ where the components mixed can be generated. When the Y component is composed of island components of various sizes, it is easy to divide by a physical action, so that it is a suitable sea-island type fiber. In particular, 0.06 to 0.
Physically splittable fibers containing island components having a diameter of 2 (preferably a diameter of 0.08 to 0.18) are easily used because they are easily split and entangled. If the island component includes one having a diameter of 1 to 5 μm, after dividing and entangled, the X component which is a sea component is further removed to generate ultra-fine fibers B ′ Also, the surface frictional resistance can be reduced.

The physical action in the present invention includes, for example, the action of a needle punch, the action of a fluid flow such as a water stream,
There is an operation of a calender or an operation of a flat plate press.
Among these, the action of a fluid stream such as a needle punch or a water stream that can be entangled simultaneously with the division of the physically splittable fiber is preferable, and the action of a fluid stream such as a water stream that can be more uniformly split and entangled. Is more preferable.

The poor compatibility of the present invention refers to a case where a side-by-side type conjugate fiber is spun from a target resin, and the conjugate fiber can be split by applying a shearing force with a finger.

Another physically splittable fiber of the present invention includes:
As shown in the schematic cross-sectional view of the fiber in FIG. 2, there is a multiple bimetallic fiber in which an X component and a Y component that is poorly compatible with the X component are alternately laminated in a layered form. When applied, the ultrafine fiber B ₁ composed of the X component and Y
The microfine fibers B ₂ consisting of components can be generated.

FIG. 3 shows another physically splittable fiber.
As shown in the schematic cross-sectional views of the fibers in (a) and (b), chrysanthemum flower in which the X component is divided by the Y component which is poorly compatible with the X component and extends from the inside of the fiber (preferably the fiber axis) to the fiber surface. has a type fibers, if Hodokose a physical action on the chrysanthemum-type fiber, the microfine fibers B ₁ consisting of the X component, it is possible to generate and microfine fibers B ₂ consisting of Y component.

In each case, the description has been made of the case where two types of resin components are used. However, the physically splittable fiber may be made of three or more types of resin components. Can generate three types of ultrafine fibers B, and can generate four types of ultrafine fibers B when composed of four types of resin components.

Examples of the physically splittable fiber composed of three or more resin components include, for example, a sea-island type fiber, a multi-bimetal type, a chrysanthemum type, and a core in which at least one island component of the sea-island type fiber which can be split by physical action is used. Sheath type, eccentric type, or side-by-side type, at least one resin component unit (X component or Y component in FIG. 2) of a multi-bimetal type fiber that can be split by physical action is a sea-island type, a multi-bimetal type, Chrysanthemum type, core-sheath type, eccentric type, or side-by-side type, at least one resin component unit (X component or Y component in FIG. 3) of chrysanthemum type fiber that can be split by physical action is sea-island type, multiplex A bimetal type, a chrysanthemum type, a core-sheath type, an eccentric type, or a side-by-side type can be used. By using such physically splittable fibers, finer ultra-fine fibers B ′ can be generated, so that a nonwoven fabric having a better feeling can be formed. In addition, when only the microfibers B ′ having a fiber diameter of 1 μm or less are generated, the surface frictional resistance is increased, and there is no point in entangled with the microfibers B ′. Is preferred. Further, if the ultrafine fibers B and / or the ultrafine fibers B ′ can be fused, the nonwoven fabric having excellent morphological stability can be formed by fusing, and the ultrafine fibers B and / or the ultrafine fibers B can be further formed. Is composed of two or more types of resin components, and as long as crimping can be exhibited by utilizing the difference in shrinkage of the resin components, a nonwoven fabric having a better feeling and a nonwoven fabric having an excellent elasticity can be formed.

As the resin component constituting the physically splittable fiber of the present invention, two or more resin components having poor fiber compatibility with each other are selected from resin components having the same fiber-forming ability as the above-mentioned removable splittable fiber. For example, when two resin components are used, there are combinations of polyamide and polyester, polyamide and polyolefin, and polyester and polyolefin.

The resin component constituting the ultrafine fiber B that can be generated from the physical splittable fiber includes a remover for the resin component of the removable splittable fiber, which has a low removal rate but can be removed. This is preferable because, at the same time as removing the resin component of the releasable splittable fiber, a part of the resin component of the ultrafine fiber B can be removed, and a nonwoven fabric having a better feeling can be formed. When the removal rate of the resin component of the releasable splittable fiber is set to 1, the resin component constituting the ultrafine fiber B is removed by a removing agent that removes the resin component of the releasable splittable fiber.
Preferably, the removal rate is between 2 and 0.7,
More preferably, the removal rate is 0.5. As the resin component of the ultrafine fiber B, for example, when the removal component of the removable type splittable fiber is a copolymerized polyester and the remover is a suitable alkaline aqueous solution, polyester, diol such as polybutylene succinate and dicarboxylic acid are used. Examples include acid condensation polymers.

The ultrafine fiber B is composed of two or more types of resin components, and one or more types of resin components are removed to obtain a fiber diameter of 1 μm.
When it can be generated by including the ultra-fine fibers B ′ exceeding μm, a nonwoven fabric having a better feeling can be formed without impairing the action of lowering the surface frictional resistance. The resin component of the ultrafine fiber B may be removed simultaneously with the removal of the resin component of the removable splittable fiber, or the resin component of the ultrafine fiber B may be removed after removing the resin component of the removable splittable fiber. Alternatively, the resin component of the removable splittable fiber may be removed after removing the resin component of the microfine fiber B. When simultaneously removing the resin component of the removable splittable fiber and the resin component of the microfine fiber B, as the resin constituting the microfine fiber B,
Assuming that the removal rate of the resin component of the removable splittable fiber is 1,
A resin component that can be removed at a removal rate of 0.7 or more, preferably 0.8 or more, and most preferably 0.9 or more with a remover that removes the resin component of the removable splittable fiber; 2
Hereinafter, it is preferable to contain a resin component which is preferably removed by not more than 0.1, most preferably not more than 0.05.

The combination of the resin components of the ultrafine fiber B is, for example, a case where the removal component of the releasable splittable fiber is a copolymerized polyester, and the removal agent is a suitable alkali aqueous solution, and it is composed of two types of resin components. There is a combination of a polyester having a removal rate of 0.9 or more and a polyolefin having a removal rate of 0.2 or less, a polylactic acid having a removal rate of 0.9 or more, and a polyolefin having a removal rate of 0.2 or less. .

On the other hand, examples of the combination of the resin component that requires removal of the resin component of the microfine fiber B separately from the removal of the resin component of the removable splittable fiber include, for example, the removal component of the removable splittable fiber is copolymerized. When the removing agent is an aqueous alkaline solution and the resin component of the microfine fiber B contains polystyrene and nylon, the removing component of the removable splittable fiber is polylactic acid, the removing agent is an aqueous alkaline solution, The resin component may include polyethylene and nylon.

The ultrafine fibers B and / or ultrafine fibers B ′ which can be generated from such physically splittable fibers need not have a single fiber diameter, but have various fiber diameters. May be. The average fiber diameter is preferably 7 μm or less, more preferably 6 μm or less, so as not to impair the feeling and the filtering performance of the nonwoven fabric. On the other hand, the average fiber diameter of the ultrafine fibers B and / or the ultrafine fibers B ′ is 0.
When the diameter is smaller than 01 μm, the coefficient of friction increases, and the fibers easily fall off. Therefore, the diameter is preferably 0.01 μm or more. In addition, if the fiber diameter is only 1 μm or less, it is difficult to lower the surface friction resistance, and the fiber diameter is 1 μm.
Ultrafine fiber B and / or ultrafine fiber B ′ having a fiber diameter exceeding
Preferably. The number of ultrafine fibers B or ultrafine fibers B ′ that can be generated from one physically splittable fiber is not particularly limited, but is preferably about 3 to 10,000. Further, ultrafine fibers B and / or ultrafine fibers B ′ having different fiber cross-sectional shapes may be mixed.

The removable splittable fiber or the physically splittable fiber which can be used in the present invention is prepared by a conventional composite spinning method,
Spinning can be easily performed by a mixed spinning method or an appropriate combination thereof. Further, a flame retardant, an antistatic agent, a moisture absorbent, a colorant, a dye, a conductive agent, a hydrophilizing agent, and the like may be mixed as long as the spinnability and the fiber strength are not reduced.
The fineness of the removable splittable fiber and the physically splittable fiber is preferably 88 to 550 μg / m.

The nonwoven fabric of the present invention comprises an entangled layer mainly composed of ultrafine fibers A generated from the above-mentioned releasable splittable fibers and an entangled layer containing ultrafine fibers B generated from physically splittable fibers. It has at least one surface. More precisely, the ultrafine fibers A are in a state in which the bundle is broken, dispersed, and entangled with the surrounding fibers. This state is remarkable when the entangled layer mainly composed of the fine fibers A is exposed on one surface. As described above, since the layer mainly including the fine fibers A having an average fiber diameter of 1 μm or less is included, the entangled layer including the fine fibers B generated from the physically splittable fibers has excellent feeling and filtration performance. Since it has on one surface, at least one surface has low surface frictional resistance, and furthermore, both the layer mainly composed of the ultrafine fibers A and the layer containing the ultrafine fibers B are entangled, so that the surface resistance is excellent.

The fibers other than the ultrafine fibers A of the entangled layer mainly composed of the ultrafine fibers A include, for example, physically splittable fibers, ultrafine fibers B generated from the physically splittable fibers and / or ultrafine fibers B ′, Natural fibers such as silk, wool, cotton, hemp, regenerated fibers such as rayon fibers, semi-synthetic fibers such as acetate fibers, polyamide fibers, polyvinyl alcohol fibers, acrylic fibers, polyester fibers, polyvinyl chloride fibers,
Synthetic fibers such as polyvinylidene chloride fibers, polyurethane fibers, polyethylene fibers, polypropylene fibers, and aromatic polyamide fibers, or composite fibers such as a core-sheath type, an eccentric type, and a side-by-side type can be used.

On the other hand, the fibers other than the ultrafine fibers B of the entangled layer containing the ultrafine fibers B include, for example, removable splittable fibers, ultrafine fibers A generated from the removable splittable fibers, physically splittable fibers, and physical splittable fibers. Ultra-fine fibers B ′ generated from the splittable fibers,
Alternatively, the same fibers as the fibers other than the ultrafine fibers A of the entangled layer mainly composed of the ultrafine fibers A can be used. In addition, if the ultrafine fibers B are contained in the layer in an amount of 10 mass% or more, a sufficiently low surface friction resistance can be obtained.

In addition, as a resin component constituting the ultrafine fiber B, a removing agent for removing the resin component of the releasable splittable fiber is used to remove the resin component of the releasable splittable fiber at a lower removal rate (removal type). If the removal rate of the resin component of the splittable fiber is 1, 0.2 to 0.7, preferably 0.2 to 0.
When the resin component contained in 5) is contained, when the resin component of the removable splittable fiber is removed, a part of the ultrafine fiber B is removed at the same time, and the flexibility of the fiber is generated. Excellent non-woven fabric.

Further, the ultrafine fibers B contained in the above nonwoven fabric
Is composed of two or more types of resin components, and can remove one or more types of resin components to produce ultrafine fibers B ′ including fibers having a fiber diameter of more than 1 μm. The nonwoven fabric having the entangled layer containing B ′ on at least one surface has a sufficiently low surface friction resistance and has a better feeling. In addition, this nonwoven fabric is not in a bundle state, but includes a layer mainly composed of microfibers A dispersed and entangled with surrounding fibers. The ultrafine fibers B ′ are not in the state of a bundle but are dispersed and entangled with the surrounding fibers.

Next, an example of the method for producing a nonwoven fabric of the present invention will be briefly described. First, one or more fiber webs mainly composed of removable splittable fibers as described above and fiber webs including physically splittable fibers are formed. Examples of a method for forming the fiber web include a dry method such as a card method, an air lay method, a melt blow method, and a spun bond method, and a wet method. The fiber length varies depending on the method of forming the fiber web. When the former is formed by the dry method (excluding the case of forming by the melt blow method or the spun bond method), a fiber having a length of about 20 to 110 mm is used, and the latter is used. 1 to 30 m when formed by the wet method of
Use fibers with a length of about m. The method of forming a fiber web mainly comprising removable splittable fibers and a fiber web including physically splittable fibers may be different.

Next, at least two fiber webs of the fiber web mainly composed of the removable splittable fibers formed as described above and the fiber web containing the physically splittable fibers are combined with the fiber web containing the physically splittable fibers. Are laminated so that at least one surface can be formed. In addition, you may laminate | stack fiber webs other than the fiber web which mainly contains a releasable splittable fiber and the fiber web which contains a physically splittable fiber.

Then, a fluid stream such as a water stream or a needle acts on the laminated fiber web to divide the physically splittable fiber to generate ultrafine fibers B, and to entangle the fibers to form an entangled fiber web. To form Among them, the fluid flow can be uniformly and densely entangled and divided, so that it is a more preferable entanglement method. In addition, each fiber web may be laminated after being entangled, and then entangled again to form an entangled fiber web.

The preferred fluid stream is preferably water which is easy to handle in production. As the entanglement condition by the fluid flow, for example, a nozzle diameter of 0.05 to 0.3
mm, preferably 0.08 to 0.2 mm, pitch 0.2 to
3 mm, preferably 0.4-2 mm using a nozzle plate arranged in one or more rows, pressure 0.98-29MPa,
Preferably, a fluid flow of 4.9 to 25 MPa is sprayed on the laminated fiber web. The pressure of the fluid flow may be changed, or the nozzle plate may be swung or vibrated.
Further, when the fluid flow is applied from the fiber web side including the physically splittable fibers, the physically splittable fibers are more easily split.

Further, by enlarging the non-opening portion of the support such as a net or a perforated plate for transporting the fiber web when entangled by the fluid flow, an entangled fiber web having holes can be formed in appearance, When the non-opening portion of the support is reduced, an entangled fiber web having no pores in appearance can be formed. Specifically, the former entangled fiber web uses a coarse net of less than 50 mesh made of a thick wire exceeding a wire diameter of 0.25 mm or a perforated plate corresponding thereto, and the latter entangled fiber web is ,
It can be formed by using a fine net of 50 mesh or more consisting of a fine wire with a fine fiber diameter of 0.25 mm or less, or a perforated plate corresponding thereto.

This entangled fiber web has, on at least one surface, an entangled layer mainly composed of removable splittable fibers that have not yet been split, and an entangled layer containing ultrafine fibers B generated from physically splittable fibers. Things. In addition, a layer in which these fibers are mixed may exist between the entangled layer mainly including the removable splittable fibers and the entangled layer including the ultrafine fibers B.
This mixed layer is formed by laminating a fiber web mainly composed of removable splittable fibers and a fiber web containing physically splittable fibers and performing an entanglement treatment, or a fiber web mainly composed of removable splittable fibers. This is likely to occur when fiber webs containing physically splittable fibers are separately entangled, and then these fiber webs are laminated and entangled. Further, when the fiber webs are separately entangled and integrated by an adhesive, there is no mixed layer of the releasable splittable fiber and the ultrafine fiber B, but an adhesive layer.

Next, by removing one or more resin components of the removable splittable fibers constituting the entangled fiber web, the ultrafine fibers A are generated to form a removed entangled fiber web. The removal of one or more resin components of the removable splittable fibers to generate the ultrafine fibers A can be performed, for example, by immersing the entangled fiber web in a bath filled with a removing agent. The removed entangled fiber web has an entangled layer mainly composed of the bundle of ultrafine fibers A and an entangled layer containing the ultrafine fibers B and / or the ultrafine fibers B ′.

When the removal rate of the resin component of the removable splittable fiber is set to 1 as a resin component constituting the microfine fiber B, a removing agent used for removing the resin component of the removable splittable fiber. By the above, when the resin composition contains a resin which can be removed at a removal rate of 0.2 to 0.7 (preferably 0.2 to 0.5), one or more resin components of the removable splittable fiber are removed. At the same time as generating the ultrafine fibers A, a part of the resin component of the ultrafine fibers B can be removed, so that the flexibility of the fibers is generated, and a fiber having a better feeling can be formed.

The ultrafine fibers B which can be generated from the physical splittable fibers are composed of two or more types of resin components, and ultrafine fibers including those having a fiber diameter exceeding 1 μm by removing one or more types of resin components. In the case where B ′ can be generated, the ultrafine fibers B are simultaneously removed while removing the resin component of the removable splittable fibers.
Or the resin component of the ultrafine fiber B after removing the resin component of the removable splittable fiber, or the resin of the removable splittable fiber after removing the resin component of the ultrafine fiber B After removing the components, the entangled layer mainly composed of the bundle of ultrafine fibers A and the ultrafine fibers B ′ generated from the physically splittable fibers
A material having a better feeling, having an entangled layer containing a bundle on at least one surface, can be formed. The method of removing the resin component of the ultrafine fiber B separately from the removal of the resin component of the removable splittable fiber can be performed, for example, by immersing the entangled fiber web in a bath filled with a remover.

Then, a fluid flow is applied again to the removed entangled fiber web to form a nonwoven fabric. As described above, in the removed entangled fiber web, the ultrafine fibers A are still present in a bundle state. However, since the fluid flow is applied again, the ultrafine fibers A are not in the bundle state and are dispersed. Entangled with surrounding fibers. This state is remarkable when the entangled layer mainly composed of the fine fibers A is exposed on one surface. Therefore, the nonwoven fabric is more excellent in surface resistance. When the fluid flow is applied again to the layer containing the microfibers B ′, the microfibers B ′ are not in a bundle state, especially in the vicinity of the surface, but are dispersed and entangled with surrounding fibers. And has excellent surface resistance.

The conditions of the fluid entanglement treatment are, for example, a nozzle diameter of 0.05 to 0.3 mm, preferably 0.08
~ 0.2mm, pitch 0.2 ~ 3mm, preferably 0.4
A pressure of 0.98 to 29.4 MPa, preferably 2 to 2, from a nozzle plate in which nozzles are arranged in one or more rows at
A stream of 4.5 MPa fluid is blown against the removed entangled fiber web. The pressure of the fluid flow may be changed, or the nozzle plate may be swung or vibrated. Further, it is preferable to spray a fluid flow onto the surface having the bundle of ultrafine fibers A and the bundle of ultrafine fibers B ′.

In the case where a nonwoven fabric having no pores in appearance is formed, when the surface density of the removed entangled fiber web is X, the removal entanglement is performed at a pressure of {(X / 10) +2} (MPa) or less. Preferably, the fluid flow is sprayed onto the composite fiber web, and more preferably, the fluid flow is sprayed at a pressure of {(X / 10) +1} (MPa) or less. The wire diameter is 0.25
By using a fine net of 50 mesh or more made of a fine wire of not more than mm or a perforated plate corresponding thereto, a nonwoven fabric having no pores in appearance can be formed. In addition, you may use these conditions together.

On the other hand, in the case of forming a nonwoven fabric having a hole in appearance, a fluid flow is blown at a pressure exceeding {(X / 10) +2} (MPa) or a thick wire having a wire diameter of more than 0.25 mm is used. By using a coarse net of less than 50 mesh or a perforated plate corresponding to this, a nonwoven fabric having holes in appearance can be formed. In addition, you may use these conditions together.

The nonwoven fabric of the present invention obtained as described above has excellent feeling and filtration performance, has low surface friction resistance, and further has excellent surface resistance. for that reason,
For example, gloves, outer garments, base materials for artificial leather such as bags, interlining for clothing, cotton filling, leakproof sheets, masks, battery separators, air or liquid filters, wallpaper, interior materials for automobiles,
It can be used for applications such as partition substrates and wiping materials. Further, further processing such as dyeing processing, coloring processing with a pigment, raising processing, laminating processing, molding processing, surface treatment processing, embossing processing, and the like can be performed so as to be more suitable for various uses.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

[0052]

【Example】

(Example 1) 57.5 mass% of copolymerized polyester and 42.5 mass% of polypropylene were mixed in a pellet state, mixed and spun at 280 ° C, and fineness was 440 µg / m.
Was obtained. Next, the wound yarn is heated to 90 ° C.
Stretched 3.3 times, cut and average fiber diameter 0.21 μm
In this case, about 2,200 island components made of polypropylene were dispersed to form a removable splittable fiber having a fineness of 160 μg / m, a fiber length of 38 mm, and a circular cross section.

Next, 100% of the removable splittable fiber was used.
A unidirectional fiber web formed by a card machine was used to cross a traveling direction of the fiber web by a cross layer to form a cross fiber web A.

On the other hand, as the physical splitting fiber, fineness of 12
As shown in FIG. 3 (a) having a fiber length of 0 μg / m and a fiber length of 38 mm, a chrysanthemum flower-type splittable fiber (Kanebo) obtained by splitting a polyester component (X) with a 6 nylon component (Y) extending radially from the fiber axis. Co., Ltd., trade name: Berima X, and microfine fibers B ₁ 8 pieces of fiber diameter 3.1μm sectional fan shape made of polyester components, fiber diameter 4.5μm of microfine fibers in sectional cross shape consisting of 6-nylon components B ₂ and four ultrafine fibers B _{3 having a} straight cross section of 6 nylon components and a fiber diameter of 3.2 μm can be generated).

Next, this physically splittable fiber was made 100%
The used unidirectional fiber web formed by the carding machine was crossed by a cross layer with the traveling direction of the fiber web to form a cross fiber web B.

Next, the crossed fiber web A and the crossed fiber web B are laminated at a mass ratio of 1: 1 to form a laminated fiber web.
0.13mm diameter, 0.6 pitch
By jetting a water stream at a pressure of 7.8 MPa, 12 MPa, and 12 MPa sequentially from the nozzle plate of mm to the cross fiber web B side, the cross fiber web A side, and the cross fiber web B side, the physically splittable fibers are formed. At the same time as splitting to generate extra fine fibers B, the laminated fiber web is entangled,
An entangled fiber web having an areal density of 108 g / m ² was formed.

Next, the entangled fiber web was heated to 80 ° C.
C., immersed in a 12 mass% aqueous sodium hydroxide solution for 30 minutes to decompose and extract the copolyester of the releasable splittable fiber to generate microfiber A, and at the same time, a part of the polyester component of microfiber B It was extracted to form a removed entangled fiber web having an areal density of 72 g / m ² .

Then, after placing the removed entangled fiber web on a net having an opening of 0.147 mm, a diameter of 0.13 m was obtained.
m, a cross fiber web A (layer made of ultrafine fibers A) side, a cross fiber web B from a nozzle plate having a pitch of 0.6 mm
Pressure (5MPa, 5MPa) for the (layer containing the ultrafine fibers B) side, the cross fiber web A side, and the cross fiber web B side in this order.
a, 2 MPa, by spraying the water flow 2 MPa, and entangled again, to form a nonwoven surface density 72 g / m ^2. In the layer made of the ultrafine fibers A of the nonwoven fabric, the ultrafine fibers A were not in a bundle state, especially near the surface, but were dispersed and entangled with surrounding fibers.

Example 2 As the physically splittable fiber, a polypropylene component (X) and a polymethylpentene component (Y) having a fineness of 330 μg / m and a fiber length of 45 mm and having a cross-sectional shape as shown in FIG. And chrysanthemum-shaped splittable fiber (trade name: DF-3, manufactured by Daiwabo Co., Ltd., sectoral shape of polypropylene component, fiber diameter 5.4 μm)
And microfine fibers B ₁ 8 pieces of, can generate and microfine fibers B ₂ 8 pieces of fiber diameter 5.4μm sectional fan shape consisting of polymethylpentene component) was prepared.

Next, the physically splittable fiber was made 100%
The used unidirectional fiber web formed by the carding machine was crossed by a cross layer with the traveling direction of the fiber web to form a cross fiber web B.

Thereafter, as in Example 1, the cross fiber web A and the cross fiber web B formed in the same manner as in Example 1 were formed.
Were laminated and subjected to a water entanglement treatment to form an entangled fiber web having an areal density of 88 g / m ² .

Next, in the same manner as in Example 1, the copolyester of the releasable splittable fiber was decomposed and extracted to generate ultrafine fibers A, thereby forming a reticulated entangled fiber web having an area density of 62 g / m ² . .

Then, the water entanglement was performed again in the same manner as in Example 1 to form a nonwoven fabric having an areal density of 62 g / m ² . In the layer made of the ultrafine fibers A of the nonwoven fabric, the ultrafine fibers A were not in a bundle state, especially near the surface, but were dispersed and entangled with surrounding fibers. This nonwoven fabric felt somewhat harder than the nonwoven fabric of Example 1. It was considered that this was because the resin components of the ultrafine fibers B ₁ and B ₂ generated from the physically splittable fibers were not extracted.

Example 3 In a composite spinning apparatus for sea-island type fibers, polypropylene was extruded from a nozzle for forming an island component, while 60 mass% of copolymerized polyester and 40 mass of polypropylene were fed from a nozzle for forming a sea component.
A mixture of s% and s% in a pellet state was extruded at a gear pump ratio of 8: 15.8, and composite-spun at 280 ° C. to obtain a wound yarn having a fineness of 830 μg / m.

Next, the wound yarn was subjected to 3.3 at 90 ° C.
It is double-stretched and cut, and 21 large island components composed of polypropylene having an average diameter of 2.6 μm (ratio to diameter of 0.11) and approximately 5,000 small island components composed of polypropylene having an average diameter of 0.18 μm are obtained. Dispersed, fineness 2
80 μg / m, a fiber length of 51 mm, and a physically splittable fiber having a circular cross section were formed.

Next, the physically splittable fiber was made 100%
The used unidirectional fiber web formed by the carding machine was crossed by a cross layer with the traveling direction of the fiber web to form a cross fiber web B.

Thereafter, as in Example 1, the cross fiber web A and the cross fiber web B formed in the same manner as in Example 1 were formed.
Were laminated and subjected to a water entanglement treatment to form an entangled fiber web having an areal density of 95 g / m ² . In addition, at the time of this water entanglement,
The physically splittable fibers split and became entangled.

Next, in the same manner as in Example 1, the copolyester of the releasable splittable fiber was decomposed and extracted to generate ultrafine fibers A, and at the same time, the copolyester of the physically splittable fiber was decomposed and extracted. A entangled fiber web having a surface density of 52 g / m ² was formed.

Then, water entanglement was performed again in the same manner as in Example 1 to form a nonwoven fabric having an areal density of 52 g / m ² . In the layer made of the ultrafine fibers A of the nonwoven fabric, the ultrafine fibers A were not in a bundle state, especially near the surface, but were dispersed and entangled with surrounding fibers. Further, in the layer of the non-woven fabric composed of the ultra-fine fibers B ', the ultra-fine fibers B' were not in a bundle state, especially near the surface, but dispersed and entangled with the surrounding fibers. This nonwoven fabric had a better feeling than the nonwoven fabric of Example 1. This was considered to be due to the fact that the ultrafine fibers B ′ generated from the physically splittable fibers contained fine particles having an average diameter of 0.18 μm.

(Example 4) Unidirectionality formed by blending 20 mass% of physically splittable fibers same as in Example 1 and 80 mass% of removable splittable fibers formed in the same manner as in Example 1 and using a carding machine The fiber web was crossed by a cross layer with respect to the traveling direction of the fiber web to form a cross fiber web B.

Next, in the same manner as in Example 1, the cross fiber web A formed in the same manner as in Example 1 and the above cross fiber web B are laminated and subjected to a water entanglement treatment to obtain an areal density of 120 g / m ^2.
Was formed.

Next, in the same manner as in Example 1, the copolyester of the releasable splittable fiber was decomposed and extracted to generate ultrafine fibers A, and at the same time, a part of the polyester component of the physically splittable fiber was also extracted. Thus, a removed entangled fiber web having an areal density of 68 g / m ² was formed.

Then, the water entanglement was performed again in the same manner as in Example 1 to form a nonwoven fabric having an areal density of 68 g / m ² . In the layer made of the ultrafine fibers A of the nonwoven fabric, the ultrafine fibers A were not in a bundle state, especially near the surface, but were dispersed and entangled with surrounding fibers. This nonwoven fabric had a better feeling than the nonwoven fabric of Example 1.
This was considered to be because the ratio of the microfiber A in the nonwoven fabric was high.

(Surface Friction Resistance) The coefficient of friction on the layer side of the nonwoven fabric of Examples 1 to 4 containing the ultrafine fibers B or ultrafine fibers B ′ and the layer side of the ultrafine fibers A of Example 1 was measured using a surface tester. (KES-FB4, manufactured by Kato Tech Co., Ltd.). The results were as shown in Table 1.

[0075]

[Table 1]

(Hand) The hand of the nonwoven fabrics of Examples 1 to 4 was
The evaluation was made by 10 panelists. In this evaluation, the nonwoven fabric of Example 1 was set as a standard of 3, and 4 when the texture was slightly better, 5 when the texture was better, 2 when the texture was slightly poor, and 1 when the texture was very poor. age,
The panelists evaluated the results on a scale of 5 and rounded off the average value of 10 panelists to the nearest decimal point. The results are also shown in Table 1.

(Surface Resistance) The surface resistance of the nonwoven fabric layer of Examples 1 to 4 containing the ultrafine fibers B or ultrafine fibers B ′ and the layer side of the ultrafine fibers A of Example 1 were measured according to JIS.
The evaluation was performed using L 1076 (Method A, ICI type tester). The results are as shown in Table 1.

[0078]

The nonwoven fabric of the present invention is mainly composed of ultrafine fibers A generated from removable splittable fibers capable of removing one or more resin components to generate ultrafine fibers A having an average fiber diameter of 1 μm or less. It has at least one entangled layer and an entangled layer containing microfine fibers B generated from physically splittable fibers capable of generating microfine fibers B by being split by a physical action. As described above, since the layer mainly including the fine fibers A having an average fiber diameter of 1 μm or less is included, the fine fibers B generated from the physically splittable fibers capable of generating the fine fibers B are excellent in feeling and filtration performance. Since at least one surface has the entangled layer containing at least one surface, the surface friction resistance of at least one surface is low, and furthermore, both the layer mainly composed of the microfine fibers A and the layer containing the microfine fibers B are entangled. Excellent resistance.

In the method for producing a nonwoven fabric according to the present invention, at least two fiber webs of a fiber web mainly composed of removable type splittable fibers and a fiber web containing physically splittable fibers are used. Laminating the fiber web so as to form at least one surface, applying a fluid flow to the laminated fiber web to divide the physically splittable fibers to generate microfibers B and to entangle them. A step of forming a conjugate fiber web, a step of removing one or more resin components of the removable splittable fiber to generate ultrafine fibers A, and forming a removed entangled fiber web, and a removed entangled fiber web Forming a non-woven fabric by applying a fluid flow again to the non-woven fabric. Therefore, it is a method that can easily produce the nonwoven fabric of the present invention.

[Brief description of the drawings]

FIG. 1 shows an example of a cross-sectional shape of a removable or physically splittable fiber of the present invention.

FIG. 2 shows another example of the cross-sectional shape of the removable or physically splittable fiber of the present invention.

FIG. 3 (a) Another example of the cross-sectional shape of the removable or physically splittable fiber of the present invention (b) Another example of the cross-sectional shape of the removable or physically splittable fiber of the present invention

[Explanation of symbols]

 X resin component Y resin component

Claims (6)

[Claims] 1. An entangled layer mainly composed of ultrafine fibers A generated from a removable splittable fiber capable of generating one or more resin components and generating ultrafine fibers A having an average fiber diameter of 1 μm or less,
A nonwoven fabric comprising, on at least one surface, an entangled layer containing microfine fibers B generated from physically splittable fibers capable of generating microfine fibers B by being split by a physical action. 2. As a resin component constituting the ultrafine fiber B,
When the removal rate of the resin component of the removable splittable fiber is set to 1, it can be removed at a removal rate of 0.2 to 0.7 by the removing agent used to remove the resin component of the removable splittable fiber. The nonwoven fabric according to claim 1, characterized in that the nonwoven fabric comprises: 3. An entangled layer mainly composed of ultrafine fibers A generated from a releasable splittable fiber capable of generating one or more types of resin components and generating ultrafine fibers A having an average fiber diameter of 1 μm or less;
It is divided by physical action and is composed of two or more kinds of resin components, and one or more kinds of resin components are removed to obtain ultrafine fibers B ′. A nonwoven fabric comprising an entangled layer containing the generated ultrafine fibers B 'on at least one surface. 4. A fiber web mainly comprising removable splittable fibers and a fiber web containing physically splittable fibers, and at least one fiber web containing physically splittable fibers is provided on at least one surface. Laminating so that it can be formed, and applying a fluid flow to the laminated fiber web to divide the physically splittable fiber to generate microfine fibers B and entangle to form an entangled fiber web. Removing one or more resin components of the removable splittable fibers to generate ultrafine fibers A and forming a removed entangled fiber web;
And applying a fluid flow to the removed entangled fiber web again to form a nonwoven fabric. 5. When the removal rate of the resin component of the removable splittable fiber is set to 1, the removal agent used for removing the resin component of the removable splittable fiber is 0.2 to 0.7. A physically splittable fiber capable of generating an ultrafine fiber B containing a resin component that can be removed at a removal rate is used.
The method for producing a nonwoven fabric according to claim 4, wherein in the step of removing the resin components of at least one kind and generating the ultrafine fibers A, a part of the resin component of the ultrafine fibers B is also removed at the same time. 6. A fiber web mainly composed of removable splittable fibers, and an ultrafine fiber B comprising two or more types of resin components and capable of removing one or more types of resin components to generate ultrafine fibers B ′. Of a fibrous web containing physically splittable fibers that can be generated,
Laminating at least two fiber webs such that the fiber webs containing the physically splittable fibers form at least one surface, applying a fluid flow to the stacked fiber webs to split the physically splittable fibers Forming ultra-fine fibers B and entangled to form an entangled fiber web, generating ultra-fine fibers A from the removable splittable fibers, and generating ultra-fine fibers B ′ from the ultra-fine fibers B Forming a removed entangled fiber web; and applying a fluid flow to the removed entangled fiber web again to form a nonwoven fabric.