TWI664332B - Modified cross-section fiber - Google Patents

Abstract

An object of the present invention is to provide a special-shaped cross-section fiber that can be efficiently produced by dividing and using the composite fiber. The present invention relates to a special-shaped cross-section fiber, which is a special-shaped cross-section fiber having the following components: (1) a plurality of composite fibers including a first thermoplastic resin and a second thermoplastic resin having a melting point or softening point lower than the first thermoplastic resin; The structure and (2) a connection body including a third thermoplastic resin having a melting point or a softening point higher than the second thermoplastic resin, and at least two composite fiber structures are connected by the connection body at any fiber cross section.

Description

Profiled fiber

The present invention relates to a special shaped fiber. More specifically, it is related to a special-shaped cross-section fiber that is excellent in splitability and that the fine composite fiber structure can be derived as a fine composite fiber independently after the split.

The industry has been conducting research on various split composite fibers. For example, Patent Document 1 proposes that by using a split-type composite fiber containing a polyolefin-based resin, one component of the polyolefin-based resin contains an ethylene-vinyl alcohol copolymer having a saponification degree of 95% or more and 1 to 30% by weight. Resin by weight to improve the resolvability. Patent Document 2 proposes that a thermoplastic resin using two components having different thermal shrinkage ratios can be easily divided using a difference in thermal shrinkage during heat treatment. However, the divided fibers of Patent Literature 1 and Patent Literature 2 are all single-component, and the thermal bonding point at the time of non-woven fabric is reduced, and the strength of the non-woven fabric cannot be said to be sufficient.

Patent Document 3 proposes a fiber which is a split composite fiber having a cross-sectional structure in which a single component A and a component B of a composite structure including a core component and a sheath component are alternately arranged. The form of the core composite structure remains. Therefore, a part of the fibers of the composite structure remain after the division.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2002-088583

[Patent Document 2] Japanese Patent Laid-Open No. 2006-328628

[Patent Document 3] Japanese Patent Laid-Open No. 2011-009150

However, regarding the split type composite fiber of Patent Document 3, since the outer periphery of the fiber cross section orthogonal to the long-axis direction of the split type composite fiber is circular, the bonding area of the component A and the component B is substantially increased. Because of the large structure, high external stress such as high-pressure water jets must be applied at the time of division, and further improvement in division is expected.

Therefore, an object of the present invention is to provide a special-shaped cross-section fiber that can be efficiently produced by dividing and using the composite fiber.

The present inventors have conducted diligent research in order to solve the above-mentioned problems, and as a result, they have found that a special-shaped cross-section fiber having a structure in which at least two composite fiber structures are connected by a connection body can achieve a desired purpose, and completed the present invention.

That is, the present invention has the following configuration.

[1] A special-shaped cross-section fiber, which is a special-shaped cross-section fiber having the following components: (1) a plurality of composite fiber structures including a first thermoplastic resin and a second thermoplastic resin having a melting point or softening point lower than the first thermoplastic resin And (2) a third thermoplastic resin having a melting point or softening point higher than that of the second thermoplastic resin Resin connected body, and at least two composite fiber structures are connected by the connected body at an arbitrary fiber cross section.

[2] The shaped cross-section fiber according to [1], wherein the connected body further includes a second thermoplastic resin and has a structure in which an outer periphery of the third thermoplastic resin is covered with the second thermoplastic resin.

[3] The special-shaped cross-sectional fiber according to [1] or [2], wherein a cross-sectional shape of the composite fiber structure is substantially circular or polygonal.

[4] The special-shaped fiber according to any one of [1] to [3], which has two to six composite fiber structures.

[5] The shaped cross-section fiber according to any one of [1] to [4], wherein the first thermoplastic resin and the third thermoplastic resin are the same resin.

[6] The shaped fiber according to any one of [1] to [5], wherein the second thermoplastic resin occupies a surface of the composite fiber structure other than a connection portion with the connection body.

[7] The shaped fiber according to any one of [2] to [6], wherein the third thermoplastic resin accounts for 20% or more of the cross-section of the connected body.

[8] The shaped fiber according to any one of [2] to [7], wherein the second thermoplastic resin contained in the connected body and the second thermoplastic resin contained in the composite fiber structure Fusion integration.

[9] The special-shaped cross-section fiber according to any one of [1] to [8], which has a structure in which the composite fiber structure body is arranged at a substantially equal interval around the center of one of the composite fiber structures. The three surrounding composite fiber structures are connected to the one central composite fiber structure by the connecting body.

[10] The shaped fiber according to any one of [1] to [9], in terms of the relationship between one of the composite fiber structures and one of the connected bodies connected thereto, The length of the connecting portion between the composite fiber structure and the connecting body is 65% or less of the outer peripheral length of the composite fiber structure.

The deformed cross-section fiber of the present invention is excellent in glossiness, concealability, and drainage of water. In particular, fine composite fibers can be efficiently produced by dividing and using them. In addition, by using a composite fiber derived from the division, a high-strength nonwoven fabric can be obtained.

1A, 1B, 1C, 1D, 1E, 1F‧‧‧shaped fiber

11‧‧‧The first thermoplastic resin

12‧‧‧The second thermoplastic resin

13‧‧‧The third thermoplastic resin

14‧‧‧ composite fiber structure

15‧‧‧ Link

Bonding length of X‧‧‧ composite fiber structure 14 and connecting body 15

Y‧‧‧Maximum width Y of composite fiber structure 14

Z‧‧‧ Length of the connecting portion of the composite fiber structure 14 and the connecting body 15

1 (a) to 1 (f) are schematic diagrams showing a fiber cross section orthogonal to the major axis direction of the profiled fiber of the present invention.

FIG. 2 is a fluorescence microscope photograph (20 times magnification) of a fiber cross section orthogonal to the major axis direction of the profiled fiber obtained in Example 1. FIG.

FIG. 3 is a scanning electron microscope (Scanning Electron Microscope, SEM) photograph (1000-fold magnification) showing the split state of the irregular-shaped fiber obtained in Example 1. FIG.

Hereinafter, the present invention will be described in more detail.

The fiber of the present invention is a special-shaped cross-section fiber having a plurality of composite fiber structures, and is a special-shaped cross-section fiber that is divided into a plurality of fine composite fibers.

The special-shaped cross-section fiber of the present invention is a special-shaped cross-section fiber having the following components: (1) a plurality of composite fiber structures including a first thermoplastic resin and a second thermoplastic resin having a melting point or softening point lower than the first thermoplastic resin, and ( 2) A joined body including a third thermoplastic resin having a melting point or a softening point higher than the second thermoplastic resin, and at least two composite fiber structures are connected by the joined body at an arbitrary fiber cross section.

In this specification, a cross section orthogonal to the long axis direction of a fiber is referred to as a "cross section" or a "fiber section".

The profiled shape of the profiled-section fiber is not particularly limited as long as it has the above-mentioned configuration. In order to make the present invention easier to understand, an example of the cross-section of the profiled-section fiber of the present invention is shown in FIG. 1.

Examples of the shaped fiber of the present invention include shaped fibers 1A, 1B, 1C, 1D, 1E, and 1F shown in FIGS. 1 (a) to 1 (f). A composite fiber structure 14 including a first thermoplastic resin 11 and a second thermoplastic resin 12 having a melting point or softening point lower than the first thermoplastic resin 11 at an arbitrary fiber cross section orthogonal to the major axis direction of the irregular-shaped fibers 1A to 1F. Many of them are connected by a connecting body 15 including a third thermoplastic resin 13 having a melting point or softening point higher than that of the second thermoplastic resin 12. In the profiled fiber, the shape of the fiber cross section may be geometrically or mechanically symmetrical or asymmetric.

In FIGS. 1 (a) to 1 (f), the number of composite fiber structures 14 is two to four. However, the number of composite fiber structures in the present invention is not particularly limited as long as it is two. Above. From the viewpoint of the structure of the spinning nozzle used in the production of the profiled fiber and the maintenance of the profiled structure at the time of spinning, the number of composite fiber structures 14 is preferably 2 to 6, and more preferably 3 to 6 article.

Among them, as shown in FIG. 1 (c) and FIG. 1 (f), it is particularly preferable for the fibers of the special-shaped cross-sections 1C and 1F having the following structure because the fibers can easily maintain the special shape and the splittability is also improved. Therefore, the structure is The three composite fiber structures 14 arranged at approximately equal intervals around the centrally located one of the composite fiber structures 14 are each connected to the centrally located one of the composite fiber structures 14 by a connecting body 15.

In addition, if there are too many composite fiber structures 14, the structure of the special-shaped fiber becomes complicated, and high external stress may be applied during division.

In the present invention, the composite fiber structure 14 is preferably a sheath-core type composite fiber having the first thermoplastic resin 11 as a core component and the second thermoplastic resin 12 as a sheath portion, or the second thermoplastic resin 12 occupying 30% of the fiber periphery. % By side type fiber. When the composite fiber structure 14 is a sheath-core type composite fiber, the second thermoplastic resin 12 only needs to occupy the outer periphery of the composite fiber, and may be a homo-core type or an off-core type.

The cross-sectional shape of the composite fiber structure 14 is preferably substantially circular or polygonal. When the fiber cross section is substantially circular or polygonal, the bonding area during the thermal bonding process of the first thermoplastic resin 11 and the second thermoplastic resin 12 can be increased.

The structure of the connecting body 15 is not particularly limited, and may be a structure formed of only the third thermoplastic resin 13 as shown in Figs. 1 (a) to 1 (c), or as shown in Figs. 1 (d) to 1 ( f) shows the third thermoplastic resin 13 and other thermoplastic trees A structure made of a grease such as the second thermoplastic resin 12. In particular, from the viewpoint of fusion and integration with the composite fiber structure 14, the other thermoplastic resin is preferably a second thermoplastic resin.

When the connection body 15 is formed of the third thermoplastic resin 13 and another thermoplastic resin (second thermoplastic resin 12), it is preferable to have a structure in which the second thermoplastic resin 12 covers the periphery of the third thermoplastic resin 13.

When the connecting body 15 includes the third thermoplastic resin 13 and the second thermoplastic resin 12, and particularly when the second thermoplastic resin 12 has a structure covering the periphery of the third thermoplastic resin 13, the connecting body 15 is a structure as follows That is, the third thermoplastic resin 13 and the second thermoplastic resin 12 are in contact with each other at an interface in an arbitrary cross section orthogonal to the major axis direction of the shaped fiber. It is preferable that the third thermoplastic resin 13 occupies 20% or more of the cross section of the connecting body 15. The proportion of the third thermoplastic resin 13 in the cross-section of the connecting body 15 is more preferably 60 to 100%, and most preferably 80% to 100%. If it is the said range, since the separability of the composite fiber structure 14 and the connection body 15 is improved, the special cross-section fiber 1A-the special cross-section fiber 1F can be easily divided.

When the connecting body 15 includes the third thermoplastic resin 13 and the second thermoplastic resin 12, the second thermoplastic resin 12 included in the composite fiber structure 14 and the second thermoplastic resin 12 included in the connecting body 15 are preferred. The contact surface is fused and integrated. Since the contact surfaces of the composite fiber structure 14 and the connecting body 15 are melt-integrated, the processing stability during spinning becomes good.

The length of the connecting body 15 is not particularly limited. In the case of a fiber having a fineness of 5 dtex to 30 dtex, from the viewpoint of maintaining spinnability and an irregular cross-sectional shape, the range is from 2 μm to 10 μm, and preferably from 4 μm to 8 μm. If it is the said range, processing stability at the time of spinning becomes favorable, and it is preferable.

In addition, in the present invention, when the contact surfaces of the composite fiber structure 14 and the connection body 15 are melt-integrated, the length of the third thermoplastic resin 13 toward the composite fiber structure 14 is defined as the length of the connection body. The third thermoplastic resin 13 connects two composite fiber structures 14 in a cross section orthogonal to the major axis direction of the shaped fiber. In addition, hereinafter, the direction of the connected body toward the composite fiber structure may be referred to as "the longitudinal direction of the connected body".

From the standpoint of severability, it is preferable that the bonding area of the composite fiber structure 14 and the connecting body 15 is small. The smaller the bonding area between the composite fiber structure 14 and the connecting body 15 is, the smaller the external stress during the division becomes, and the easier the division becomes.

The bonding length X (see FIGS. 1 (a) and 1 (d)) of the composite fiber structure 14 and the connecting body 15 of the cross section of the special-shaped fiber is preferably a composite fiber in a direction orthogonal to the longitudinal direction of the connecting body. The structure body 14 has a maximum width Y (refer to FIGS. 1 (a) and 1 (d)) (in the case where the composite fiber structure is circular, its diameter). If the subsequent length X is equal to or less than the maximum width Y of the composite fiber structure, the division is easy. The bonding length X is preferably 50% to 95% of the maximum width Y of the composite fiber structure in a direction orthogonal to the longitudinal direction of the connected body from the viewpoint of processing stability and easy severability during spinning. , More preferably 60% ~ 90%.

In the present invention, one composite fiber structure 14 and one In terms of the relationship between one connected body 15, the length Z (see FIG. 1 (a) and FIG. 1 (d)) of the connection portion of the composite fiber structure 14 and the fiber 15 of the fiber cross section is preferably a composite fiber structure. 14 The outer peripheral length is 65% or less, and more preferably 50% to 15%. If the length Z of the connection portion is within the above range, it is easy to divide, so it is preferable. Here, the connection portion is a contact portion between the composite fiber structure 14 and the connection body 15. The length Z of the connecting portion is the length of the contact portion between the composite fiber structure 14 of the fiber cross section and the connecting body 15. As shown in FIG. 1 (d), when the connecting body 15 is formed of the third thermoplastic resin 13 and other thermoplastic resins, for example, the second thermoplastic resin 12, the length Z of the connecting portion is assumed to remain the same as the composite fiber structure 14. The length of the contact portion during construction. The outer peripheral length of the composite fiber structure 14 is an estimated length when only the composite fiber structure 14 is observed.

In addition, in the present invention, the first thermoplastic resin, the second thermoplastic resin, and the third thermoplastic resin may all use different resins. However, from the viewpoint of improving processability or separability, the third thermoplastic resin is preferably the same as the first thermoplastic resin. 1 The thermoplastic resin is the same.

As described above, the second thermoplastic resin 12 is a thermoplastic resin having a melting point or softening point lower than that of the first thermoplastic resin 11. Specifically, it is preferable to use a resin having a melting point or softening point that is 15 ° C to 150 ° C lower than the first thermoplastic resin 11. Resin, more preferably 30 ° C ~ 130 ° C. If it is the said temperature range, the thermal subsequent processing using the difference of a melting point or a softening point can be performed. In addition, in the present invention, the thermoplastic resin used is generally selected based on the temperature of the melting point, and the softening point is used for the thermoplastic resin having no melting point.

The first to third thermoplastic resins used in the profiled fiber of the present invention are not particularly limited as long as they satisfy the conditions of the melting point or softening point. Better Polyester resins that can form fibers; Polyamide resins (nylons); Polyolefin resins; Acrylonitrile-Butadiene-Styrene (ABS) resins; Acrylonitrile -Styrene, AS) resin; polystyrene resin; acrylic resin; polycarbonate; polyphenylene ether; polyacetal; polyphenylene sulfide; polyether ether ketone; liquid crystal polymer; fluororesin; urethane Resin; elastomer, etc., more preferably polyolefin resin or polyester resin. In addition, a thermoplastic resin may be produced by combining a plurality of the resins.

Examples of the polyolefin-based resin that can be used for the shaped fiber of the present invention are shown below, but are not particularly limited.

For example, polyethylene, polypropylene, polybutene-1, polyhexene-1, polyoctene-1, poly4-methylpentene-1, polymethylpentene, 1,2-polybutadiene can be used Ene, 1,4-polybutadiene and the like. Furthermore, these homopolymers may contain a small amount of ethylene, propylene, butene-1, hexene-1, octene-1 or 4 under conditions other than the monomers constituting the homopolymer. Α-olefin such as methylpentene-1 as a copolymerization component. In addition, it may contain a small amount of other ethylene-based unsaturated monomers such as butadiene, isoprene, 1,3-pentadiene, styrene, and α-methylstyrene as a copolymerization component. In addition, two or more of these polyolefin-based resins may be mixed and used.

For these, not only polyolefin resins polymerized by the usual Ziegler-Natta catalyst can be preferably used, but also polyolefin resins polymerized by the metallocene catalyst can be preferably used. Based resins and their copolymers. The melt mass flow rate (hereinafter referred to as MFR (Melt Mass Flow Rate)) of the polyolefin resin that can be used preferably is not particularly limited as long as it is a range in which spinning is possible. 1g / 10min ~ 100g / 10min, more preferably 5g / 10min ~ 70g / 10min.

As the polyolefin-based resin that can be used in the shaped fiber of the present invention, a preferred polyolefin-based resin is at least one polymer selected from the group consisting of a copolymer containing polyethylene, polypropylene, and propylene as a main component. Olefin resin. Examples include high-density polyethylene, linear low-density polyethylene, low-density polyethylene, polypropylene (propylene homopolymer), ethylene-propylene copolymer containing propylene as a main component, and ethylene containing propylene as a main component. -Propylene-butene-1 copolymer. Here, the "copolymer containing propylene as a main component" means a copolymer in which a propylene unit accounts for the largest amount among the copolymerization components constituting the copolymer.

Physical properties of polyolefins other than the MFR, such as Q value (weight average molecular weight / number average molecular weight), Rockwell hardness, and number of branched methyl chains are not particularly limited as long as they satisfy the requirements of the present invention. .

The polyester-based resin usable for the shaped fiber of the present invention can be obtained by polycondensation of a diol and a dicarboxylic acid. Examples of the dicarboxylic acid used for the polycondensation of the polyester resin include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, and sebacic acid. Examples of the diols used include ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, and 1,4-cyclohexanedimethanol.

As the polyester-based resin usable in the shaped fiber of the present invention, polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate can be preferably used. In addition, in addition to the aromatic polyester, an aliphatic polyester may also be used. Examples of preferred aliphatic polyesters include polylactic acid and polybutylene succinate. These polyester resins can be not only homopolymers but also copolyesters (copolymers Polyester (Copolyester)). In this case, as the copolymerization component, dicarboxylic acid components such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, diethylene glycol, and neopentyl glycol can be used. And other diol components, and optical isomers such as L-lactic acid. Examples of such a copolymer include polybutylene terephthalate adipate. Further, two or more of these polyester resins may be mixed and used. In consideration of raw material cost, thermal stability of the obtained fiber, and the like, the resin used in the present composite fiber is preferably an unmodified polymer composed only of polyethylene terephthalate.

In the thermoplastic resin, antioxidants, light stabilizers, ultraviolet absorbers, neutralizers, nucleating agents, epoxy stabilizers, lubricants, Additives such as antibacterial agents, flame retardants, antistatic agents, pigments and plasticizers.

Examples of the combination of the resins constituting the profiled fiber of the present invention are shown below, but are not particularly limited. From the viewpoint of processability, the first thermoplastic resin and the third thermoplastic resin are preferably the same resin. When the connected body includes the second thermoplastic resin and the third thermoplastic resin, the second thermoplastic resin included in the composite fiber structure and the second thermoplastic resin included in the connected body are the same resin.

As a combination of [the first thermoplastic resin and the third thermoplastic resin] / [the second thermoplastic resin], under the condition that the melting points of the first thermoplastic resin and the third thermoplastic resin are higher than the second thermoplastic resin, an example: polypropylene / High density polyethylene, polypropylene / low density polyethylene, polypropylene / linear low density polyethylene, ethylene-propylene copolymer / high density polyethylene, ethylene-propylene copolymer / low density polyethylene, ethylene-propylene copolymerization / Linear low-density polyethylene, polyethylene terephthalate / ethylene-propylene copolymerization Materials, polyethylene terephthalate / polypropylene, polyethylene terephthalate / high density polyethylene, polyethylene terephthalate / linear low density polyethylene, polyethylene terephthalate Ethylene glycol / low density polyethylene, polybutylene terephthalate / high density polyethylene, polybutylene terephthalate / low density polyethylene, polybutylene terephthalate / low linear Density polyethylene, polybutylene terephthalate / polypropylene, polybutylene terephthalate / ethylene-propylene copolymer, polybutylene terephthalate / polyethylene terephthalate, etc. The better combinations are polypropylene / HDPE, polyethylene terephthalate / HDPE.

In addition, when the first thermoplastic resin, the second thermoplastic resin, and the third thermoplastic resin are all different, under the condition that the melting point of the first thermoplastic resin is higher than that of the second thermoplastic resin, [first thermoplastic resin] / [second Examples of the combination of thermoplastic resin] / [third thermoplastic resin]: polypropylene / high-density polyethylene / polyethylene terephthalate, polypropylene / linear low-density polyethylene / high-density polyethylene, polypropylene / Low density polyethylene / high density polyethylene, polypropylene / high density polyethylene / ethylene-propylene copolymer, polyethylene terephthalate / high density polyethylene / ethylene-propylene copolymer, polyethylene terephthalate Ethylene glycol / HDPE / polypropylene, polyethylene terephthalate / low density polyethylene / polypropylene, polyethylene terephthalate / linear low density polyethylene / polypropylene, polyethylene Ethylene terephthalate / high density polyethylene / polybutylene terephthalate, polyethylene terephthalate / low density polyethylene / polybutylene terephthalate, polyethylene terephthalate Ethylene glycol / linear low density polyethylene / polybutylene terephthalate, polyethylene terephthalate Ester / polypropylene / polybutylene terephthalate, polybutylene terephthalate / high density polyethylene / ethylene-propylene copolymer, polybutylene terephthalate / low density poly Ethylene / ethylene-propylene copolymer, polybutylene terephthalate / linear low-density polyethylene / ethylene-propylene copolymer, and the like are not limited thereto.

The method for producing the shaped fiber of the present invention is exemplified below, but it is not particularly limited. A method for producing a shaped fiber having a different cross section when the first thermoplastic resin and the third thermoplastic resin are the same and the melting point is 15 ° C. or more higher than the second thermoplastic resin is exemplified.

The two polyolefin-based resins are fiberized by a melt spinning method using a nozzle having a special shape capable of obtaining a fiber with a special cross-section. When spinning, spinning is preferably performed at a spinning temperature in the range of 180 ° C to 350 ° C, and the extraction speed should preferably be set to about 40m / min to 1500m / min. Stretching can be multi-stretched as required, and the stretching ratio should be set to about 3 to 9 times. Further, if necessary, the obtained fiber tow is crimped, and then cut into specific lengths to produce short fibers. Alternatively, long fibers can be produced without cutting the fiber bundle.

The method of using the shaped fiber of the present invention is not particularly limited. The shaped fiber can be used as a shaped fiber, or can be used as a split fiber. It is preferably used according to the field of use.

In the present invention, when the special-shaped cross-section fiber of the present invention is used by being divided, there is a component element in the special-shaped cross-section fiber obtained by dividing and deriving a composite fiber, and the composite fiber structure is used as the composite fiber structure. As a basis, the fiber obtained by dividing and deriving is called a composite fiber and is used in a differentiated manner. The derived composite fiber is not particularly limited, and may be a structure in which the connected body and the composite fiber structure are completely separated, or a structure in which at least a part of the connected body is maintained in a connected state. Made. The derived composite fibers can be circular or non-circular.

There is no particular limitation on the method of dividing the profiled fiber, and it can be performed by a known method such as cotton mesh, needle punching after non-woven fabric treatment, high-pressure liquid flow treatment, or external stress or other factors such as stretching treatment in the fiber manufacturing step. Fibers are shrunk and divided by processes such as heat treatment.

The shaped fiber of the present invention is not particularly limited. For example, in the case of a thermoplastic resin containing two components, the composite ratio is in the range of 10/90 to 90/10, and more preferably 30/70 to 70 /. 30.

The monofilament fineness of the shaped fiber of the present invention before division is not particularly limited, but is preferably 0.6 dtex to 10 dtex, and more preferably 1.0 dtex to 6.0 dtex. In addition, when the special-shaped fiber is divided by high-pressure liquid flow treatment or the like, the average monofilament fineness of the ultrafine composite fiber divided from the divided connection body is preferably 0.5 dtex or less, and more preferably 0.3 dtex or less.

The shaped fiber of the present invention can be formed into a fiber shaped body according to the application through advanced processing steps, if necessary.

Here, the fiber-formed body may be any fiber-formed body as long as it has a cloth-like form, and is not particularly limited. Examples include woven fabrics, knitted fabrics, and non-woven fabrics. In addition, the fibers of the present invention may be blended with other fibers or blended to form a fiber formed body. In addition, it may be a fiber molded body laminated on a net, a woven fabric, a knitted fabric, or a non-woven fabric uniformly made by a carding method, an air-laid method, or a papermaking method.

The fiber shaped body of the present invention may U.S.-China blended cotton or other fibers are used. Examples of the other fibers include synthetic fibers such as polyamide, polyester, polyolefin, and acrylic, natural fibers such as cotton, wool, and hemp, and copper, copper ammonia ( cupra), acetate and other regenerated fibers, semi-synthetic fibers, etc.

In this step, after spinning the fiber, a surfactant can be attached to the surface of the fiber for the purpose of antistatic of the fiber and imparting smoothness to the fiber formed body in order to improve processability. The type and concentration of the surfactant are appropriately adjusted depending on the application. As a method of adhesion, a roll method, a dipping method, or the like can be used. The adhesion may be performed in any of the spinning step, the stretching step, and the crimping step. Furthermore, regardless of the short fibers and long fibers, the surfactant may be adhered after a step other than a spinning step, a stretching step, and a crimping step, for example, a step of forming a fiber molded body.

The fiber length of the special-shaped fiber of the present invention is not particularly limited. In the case of using a card to make a cotton web, a special-shaped fiber having a fiber length of 20 mm to 76 mm is generally used. It is better to use profiled fiber with a fiber length of 2mm ~ 20mm.

The manufacturing method of a nonwoven fabric is illustrated as an example of the manufacturing method of the fiber molded body obtained from the profile fiber of this invention.

For example, using a short fiber manufactured by the manufacturing method of the said profile fiber, and using a carding method, an air-spinning method, or a papermaking method, the cotton web of a desired unit area weight is produced. The fiber web produced by the method can be divided into fine fibers by a known method such as a needle punch method and high-pressure liquid flow treatment to obtain a fiber formed body. Furthermore, this fiber molded body can be further processed by a well-known processing method, such as a hot air or a hot roll.

The basis weight of the fiber formed body of the present invention is not particularly limited, but is preferably 10 g / m ² to 200 g / m ² .

The product obtained by using the profiled fiber of the present invention is excellent in glossiness, concealment, and water drainage, and can be preferably used in absorbent articles such as diapers, sanitary napkins, and incontinence pads. In addition, the non-woven fabric manufactured by using the composite fiber obtained by dividing the profiled fiber of the present invention can be used in absorbent articles such as diapers, sanitary napkins, incontinence pads, medical gowns, surgical gowns, and the like, Wallboards, sliding door paper, flooring materials and other interior materials, cover materials, cleaning rags, kitchen garbage bags and other life-related materials, disposable toilets, toilet pads and other toiletry Products, pet diapers, pet diapers, pet towels and other pet supplies; wipes, battery separators, rags, filter papers, cushioning materials, oil-absorbing materials, ink tanks and other absorbent materials, industrial materials, general medical materials , Bedding, care products and other fiber products.

[Example]

Hereinafter, examples are described by the present invention, but the present invention is not limited to these.

(Thermoplastic resin)

The following resins were used as the thermoplastic resin constituting the composite fiber.

First thermoplastic resin: Propylene homopolymer (PP for short) with MFR (230 ° C, load 21.18N) of 16g / 10min and melting point of 163 ° C

Second thermoplastic resin: high density polyethylene (PE for short) with a density of 0.96g / cm ³ , MFR (190 ° C, load 21.18N) of 16g / 10min, and a melting point of 130 ° C

Third thermoplastic resin: the same propylene homopolymer as the first thermoplastic resin

<Example 1>

(Manufacture of profiled fiber)

Using the first thermoplastic resin (PP), the second thermoplastic resin (PE), and the third thermoplastic resin (PP), using a nozzle for a profiled fiber, (the first thermoplastic resin and the third thermoplastic resin) A volume ratio of 50/50 to the second thermoplastic resin was used to spin the profiled fiber shown in FIG. 1 (f). A shaped cross-section fiber having a fineness of 9.5 dtex having a cross-sectional shape shown in FIG. 2 can be obtained.

At this time, by using an oiling roll, a fiber-treating agent mainly containing an alkyl phosphate K salt as a surfactant is brought into contact with the spun fibers, and the fiber-treating agent is adhered.

The obtained undrawn fiber was drawn at a drawing temperature of 90 ° C. using a drawing machine, and was drawn 6 times, and the fiber was cut with a cutter to obtain short fibers.

As shown in FIG. 3, the drawn fiber is divided into 0.3 dtex fine composite fibers after being divided. Since it divides by drawing, it turns out that the profile fiber of this invention has a structure which can be easily divided.

The present invention has been described in detail with reference to specific embodiments, but it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. In addition, this application is based on a Japanese patent application filed on March 31, 2014 (Japanese Patent Application No. 2014-073057), the entire contents of which are incorporated by reference. In addition, all references cited herein are incorporated herein in their entirety.

[Industrial availability]

The special-shaped fiber of the present invention can be preferably used in the field of industrial materials such as battery separators, wipes, and filter paper, and in the field of sanitary materials such as diapers and sanitary napkins.

Claims (10)

A special-shaped cross-section fiber, which is a special-shaped cross-section fiber having the following components: (1) a plurality of composite fiber structures including a first thermoplastic resin and a second thermoplastic resin having a melting point or softening point lower than the first thermoplastic resin; and (2) A connecting body including a third thermoplastic resin having a melting point or a softening point higher than the second thermoplastic resin, and at least two of the composite fiber structures are connected by the connecting body at an arbitrary fiber cross section. The special-shaped cross-section fiber according to item 1 of the scope of patent application, wherein the connected body further includes the second thermoplastic resin, and has a structure in which an outer periphery of the third thermoplastic resin is covered with the second thermoplastic resin. The special-shaped cross-section fiber according to item 1 or item 2 of the patent application scope, wherein the cross-sectional shape of the composite fiber structure is substantially circular or polygonal. The profiled fiber according to item 1 or item 2 of the scope of patent application, which has 2 to 6 composite fiber structures described above. The profiled fiber according to item 1 or item 2 of the patent application scope, wherein the first thermoplastic resin and the third thermoplastic resin are the same resin. The profiled fiber according to item 1 or item 2 of the patent application scope, wherein the second thermoplastic resin occupies a surface of the composite fiber structure body other than a connection portion with the connection body. According to the profiled fiber of item 2 in the scope of the patent application, the third thermoplastic resin accounts for more than 20% of the cross-section of the connected body. The profiled fiber according to item 2 of the scope of patent application, wherein the second thermoplastic resin contained in the connected body is melt-integrated with the second thermoplastic resin contained in the composite fiber structure. The special-shaped cross-section fiber according to item 1 or item 2 of the patent application scope has a structure in which three of the composite fiber structures are arranged at approximately equal intervals around one of the composite fiber structures located in the center. The connecting body is connected to the centrally located one of the composite fiber structures through the connecting body. The special-shaped cross-section fiber according to item 1 or 2 of the patent application scope, wherein the composite fiber having an arbitrary fiber cross-section has a relationship with respect to one of the composite fiber structures and one of the connection bodies connected to the composite fiber structure. The length of the connecting portion between the structure and the connecting body is 65% or less of the outer peripheral length of the composite fiber structure.