WO2018212211A1

WO2018212211A1 - Crimped fibers and nonwoven cloth

Info

Publication number: WO2018212211A1
Application number: PCT/JP2018/018855
Authority: WO
Inventors: 真理矢部; 拓実杉内; 南　裕; 智明武部
Original assignee: 出光興産株式会社
Priority date: 2017-05-16
Filing date: 2018-05-16
Publication date: 2018-11-22
Also published as: JPWO2018212211A1; EP3626869C0; US20200071867A1; EP3626869B1; WO2018211843A1; EP3626869A1; EP3626869A4; CN110612367A

Abstract

One of the components of these crimped fibers contains a thermoplastic resin (A), and the other component contains a thermoplastic resin (B) and a thermoplastic resin (C). The semi-crystallization time of the thermoplastic resin (A) at 25°C is shorter than the semi-crystallization time of the thermoplastic resin (B) at 25°C, and the semi-crystallization time of the thermoplastic resin (C) at 25°C is longer than the semi-crystallization time of the thermoplastic resin (B) at 25°C.

Description

Crimped fiber and non-woven fabric

The present invention relates to crimped fibers and nonwoven fabrics.

For example, three kinds of resin components having different melting points or softening points are arranged at specific positions in the short-direction cross section of the fiber so as to have bulkiness, high strength of the nonwoven fabric, and stretchability when used for the nonwoven fabric. A heat-fusible conjugate fiber has been proposed (Patent Document 1). In addition, a latent crimpable composite fiber using a core-sheath composite material using polyolefins having different melting points has been proposed (Patent Document 2).

JP 2012-251254 A JP 2012-158861 A

However, the conjugate fibers described in Patent Documents 1 and 2 have not been sufficiently crimped.

This invention is made | formed in view of such a situation, and it aims at providing the crimped fiber with high crimpability, and the nonwoven fabric which consists of this crimped fiber.

As a result of intensive studies to solve the above problems, the present inventors have found that the problems can be solved by the following invention.

That is, the present disclosure relates to the following.
[1] One component of the crimped fiber contains the thermoplastic resin (A), the other component contains the thermoplastic resin (B) and the thermoplastic resin (C), and the thermoplastic resin (A) has a temperature of 25 ° C. The half crystallization time at 25 ° C. of the thermoplastic resin (B) is shorter than the half crystallization time at 25 ° C. of the thermoplastic resin (B). A crimped fiber that is longer than the half-crystallization time at ° C.
[2] The crimped fiber according to [1], wherein the thermoplastic resin (A) has a semi-crystallization time at 25 ° C. of 0.01 seconds or less.
[3] The crimped fiber according to the above [1] or [2], wherein the thermoplastic resin (B) has a semi-crystallization time at 25 ° C. of more than 0.01 seconds and not more than 0.06 seconds.
[4] The crimped fiber according to any one of [1] to [3] above, wherein the thermoplastic resin (C) has a half crystallization time at 25 ° C. of more than 0.06 seconds.
[5] According to JIS K7210 of the thermoplastic resin (A), the melt flow rate (MFR) measured under conditions of a temperature of 190 ° C. and a load of 2.16 kg is 1 g / 10 min to 70 g / 10 min. [1] A crimped fiber according to any one of [4].
[6] According to JIS K7210 of the thermoplastic resin (B), the melt flow rate (MFR) measured under the conditions of a temperature of 230 ° C. and a load of 2.16 kg is 10 g / 10 min to 500 g / 10 min. The crimped fiber according to any one of 1] to [5].
[7] According to JIS K7210 of the thermoplastic resin (C), the melt flow rate (MFR) measured under the conditions of a temperature of 230 ° C. and a load of 2.16 kg is 10 g / 10 min to 5000 g / 10 min. [1] A crimped fiber according to any one of [6].
[8] Melting endothermic curve obtained by holding the thermoplastic resin (A) using a differential scanning calorimeter (DSC) at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. The crimped fiber according to any one of the above [1] to [7], wherein the melting point (Tm-D) defined as the peak top of the peak observed on the highest temperature side is 90 ° C. or higher and 135 ° C. or lower.
[9] Melting endothermic curve obtained by using a differential scanning calorimeter (DSC) of the thermoplastic resin (B) by holding at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. The crimped fiber according to any one of the above [1] to [8], wherein the melting point (Tm-D) defined as the peak top of the peak observed on the highest temperature side is from 120 ° C to 200 ° C.
[10] Melting endothermic curve obtained by holding the thermoplastic resin (C) using a differential scanning calorimeter (DSC) at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. The crimped fiber according to any one of the above [1] to [9], wherein the melting point (Tm-D) defined as the peak top of the peak observed on the highest temperature side is 50 ° C. or higher and 100 ° C. or lower.
[11] The crimped fiber according to any one of [1] to [10], wherein the thermoplastic resin (A) is a polyethylene resin.
[12] The crimped fiber according to any one of [1] to [11], wherein the thermoplastic resin (B) is a polypropylene resin.
[13] The crimped fiber according to [12], wherein the thermoplastic resin (B) is a propylene homopolymer.
[14] Obtained by using a differential scanning calorimeter (DSC) in the thermoplastic resin (C), holding the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raising the temperature at 10 ° C./min. The crimped fiber according to any one of the above [1] to [13], wherein the melting endotherm (ΔHD) obtained from the melting endotherm curve is 0 J / g or more and 80 J / g or less.
[15] The crimped fiber according to any one of [1] to [14], wherein the thermoplastic resin (C) has a molecular weight distribution (Mw / Mn) of less than 3.0.
[16] The content of the thermoplastic resin (C) in the total of the thermoplastic resin (A), the thermoplastic resin (B), and the thermoplastic resin (C) is 1% or more and 50% or less. The crimped fiber according to any one of [1] to [15] above.
[17] The crimped fiber according to any one of [1] to [16], wherein the crimped fiber is a side-by-side type fiber.
[18] The crimped fiber according to [17] above, wherein the resin constituting the inside of the crimped fiber is a side-by-side fiber containing the thermoplastic resin (A).
[19] The crimped fiber according to the above [17], wherein the resin constituting the inside of the crimped fiber is a side-by-side type fiber made of the thermoplastic resin (A).
[20] The crimped fiber according to the above [17], wherein the resin constituting the inside of the crimped fiber is a side-by-side fiber containing the thermoplastic resin (B).
[21] The crimped fiber according to the above [17], wherein the resin constituting the inside of the crimped fiber is a side-by-side type fiber made of the thermoplastic resin (B).
[22] A nonwoven fabric comprising the crimped fiber according to any one of [1] to [21].
[23] A multilayer nonwoven fabric obtained by laminating two or more layers, wherein at least one layer is the nonwoven fabric described in [22].

According to the present invention, a highly crimped crimped fiber and a nonwoven fabric made of the crimped fiber can be provided.

It is an image at the time of observing the side-by-side type | mold crimp fiber obtained in Example 16 with the optical microscope (200-times multiplication factor). It is an image at the time of observing the side-by-side type | mold crimp fiber obtained in Example 17 with the optical microscope (200-times multiplication factor). It is an image at the time of observing the side-by-side crimped fiber obtained in Example 18 with an optical microscope (magnification 200 times). It is an image at the time of observing the side-by-side type | mold crimp fiber obtained in Example 19 with the optical microscope (200-times multiplication factor). It is an image at the time of observing the side-by-side type | mold crimp fiber obtained in Example 20 with the optical microscope (200-times multiplication factor). It is an image at the time of observing the side-by-side type crimped fiber obtained in Example 21 with an optical microscope (magnification 200 times).

Hereinafter, the present invention will be described in detail.
In the present specification, “crimped fiber” is used to include composite spun fibers formed by side-by-side nozzles, eccentric core-sheath nozzles, deformed nozzles, or split nozzles, which are combined with different thermoplastic resins. The core-sheath fiber refers to a fiber whose cross section is composed of a “core” of the inner layer portion and a “sheath” of the outer layer portion, and the eccentric core-sheath fiber is the center of gravity position of the inner layer portion in the cross-sectional shape. Means a fiber different from the center of gravity of the entire fiber.
Moreover, in this specification, the component which contains a thermoplastic resin (A) among the components which comprise a crimped fiber is made into a "1st component", and the component containing a thermoplastic resin (B) and a thermoplastic resin (C) Is the “second component”. In the present specification, when the crimped fiber is a side-by-side fiber, one component constituting the side-by-side fiber is referred to as a “first component”, and the other component is referred to as a “second component”. Further, when the crimped fiber is a core-sheath fiber, one of the component used for the core part of the core-sheath fiber and the component used for the sheath part is referred to as a “first component”, and the other is referred to as a “second component” "

<Crimped fiber>
In the crimped fiber of this embodiment, one component of the crimped fiber includes a thermoplastic resin (A), and the other component includes a thermoplastic resin (B) and a thermoplastic resin (C), and the thermoplastic The half crystallization time of the resin (A) at 25 ° C is shorter than the half crystallization time of the thermoplastic resin (B) at 25 ° C, and the half crystallization time of the thermoplastic resin (C) at 25 ° C is the heat. It is characterized by being longer than the half crystallization time at 25 ° C. of the plastic resin (B).
In this embodiment, when the thermoplastic resin (A), the thermoplastic resin (B), and the thermoplastic resin (C) satisfy the above relationship, the first component containing the thermoplastic resin (A) is a semi-crystal at 25 ° C. The difference between the crystallization time and the semi-crystallization time at 25 ° C. of the second component containing the thermoplastic resin (B) and the thermoplastic resin (C) becomes larger, and a crimped fiber having higher crimpability is obtained. Can do.

In the present embodiment, the half crystallization time was measured by the following method.
Using FLASH DSC (manufactured by METTLER TOLEDO Co., Ltd.), the sample was heated at 230 ° C. for 2 minutes to melt, then cooled to 25 ° C. at 2000 ° C./second, and heat generation during the isothermal crystallization process at 25 ° C. The amount of change over time was measured. When the integrated value of the calorific value from the start of isothermal crystallization to the completion of crystallization is taken as 100%, the time from the start of isothermal crystallization until the integrated value of the calorific value reaches 50% is taken as the half crystallization time. .

Further, the melt flow rate (MFR) of the thermoplastic resin (A) is smaller than the MFR of the thermoplastic resin (B), and the MFR of the thermoplastic resin (B) is smaller than the MFR of the thermoplastic resin (C). From the viewpoint of enhancing the crimpability of the crimped fiber.
The melt flow rate (MFR) is measured by a measurement method defined in JIS K7210. For the thermoplastic resin (A), a temperature of 190 ° C. and a load of 2.16 kg are used. The plastic resin (C) is measured under the conditions of a temperature of 230 ° C. and a load of 2.16 kg.

Using the differential scanning calorimeter (DSC) of the thermoplastic resin (A), hold it at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raise the temperature at 10 ° C./min. The melting point (Tm-D) defined as the peak top of the peak observed in Fig. 2 is lower than the melting point (Tm-D) defined by the above conditions of the thermoplastic resin (B), and the thermoplastic resin (B) The melting point (Tm-D) is preferably higher than the melting point (Tm-D) defined by the above conditions for the thermoplastic resin (C) from the viewpoint of enhancing the crimpability of the crimped fiber.

[Thermoplastic resin (A)]
The thermoplastic resin (A) used in the present embodiment has a half crystallization time at 25 ° C. shorter than the half crystallization time at 25 ° C. of the thermoplastic resin (B) described later, preferably 0.01 seconds or less. . If the half crystallization time of the thermoplastic resin (A) at 25 ° C is 0.01 seconds or less, a crimped fiber having higher crimpability can be obtained.

The melt flow rate (MFR) of the thermoplastic resin (A) is preferably 1 g / 10 min or more, more preferably 5 g / 10 min or more, further preferably 10 g / 10 min or more, still more preferably 15 g / 10 min or more, And preferably it is 70 g / 10min or less, More preferably, it is 45 g / 10min or less, More preferably, it is 30 g / 10min or less, More preferably, it is 20 g / 10min or less.
The melt flow rate (MFR) is measured by a measurement method defined in JIS K7210, and is measured under conditions of a temperature of 190 ° C. and a load of 2.16 kg.

Using the differential scanning calorimeter (DSC) of the thermoplastic resin (A), the highest end of the melting endotherm curve obtained by holding at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. The melting point (Tm-D) defined as the peak top of the peak observed on the side is preferably 90 ° C. or higher, more preferably 100 ° C. or higher, more preferably 115 ° C. or higher, and preferably 135 ° C. or lower. More preferably, it is 130 ° C. or lower.

The thermoplastic resin (A) is not particularly limited as long as the above requirements are satisfied, but is preferably a polyethylene resin using a so-called metallocene catalyst having a narrow molecular weight distribution. The polyethylene resin may be an ethylene homopolymer or a copolymer. In the case of a copolymer, the copolymerization ratio of ethylene units exceeds 50 mol%, preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more, and still more preferably 95 mol%. That's it. Examples of the copolymerizable monomer include α-olefins having 3 to 30 carbon atoms, and specific examples include 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and the like.

Examples of commercially available ethylene homopolymers include the “ASPUN ^™ ” series (for example, “ASPUN XUS 61800.52 LE” and “ASPUN 6834”) (manufactured by Dow Chemical Co., Ltd.). Commercially available copolymers of ethylene and octene include “Affinity GA1900”, “Affinity GA1950”, “Affinity EG8185”, “Affinity EG8200”, “Engage 8137”, “Engage 8180” manufactured by Dow Chemical Co., Ltd. ”,“ Engage 8400 ”, etc. (all are trade names).

As the weight average molecular weight (Mw) of the polyethylene-based resin is increased, the crimpability of the obtained crimped fiber can be improved, but the yarn is easily broken and the spinnability is lowered. In addition, the higher the density of the polyethylene resin, the higher the crimpability of the crimped fiber obtained, but the yarn breaks easily and the spinnability is lowered. On the other hand, in the crimped fiber of the present embodiment, by using a component obtained by adding a thermoplastic resin (C) to a thermoplastic resin (B) described later as a second component, yarn breakage is suppressed and spinnability is improved. The crimpability can be further increased.

The content of the thermoplastic resin (A) in the first component is preferably 80% by mass or more, more preferably 85% by mass or more, and still more preferably 90% by mass or more, when the first component is 100% by mass. And an upper limit is 100 mass%.

[Thermoplastic resin (B)]
The thermoplastic resin (B) used in the present embodiment has a half crystallization time at 25 ° C. shorter than the half crystallization time at 25 ° C. of the thermoplastic resin (C) described later, preferably more than 0.01 seconds, More preferably 0.02 seconds or more, further preferably 0.03 seconds or more, still more preferably 0.04 seconds or more, and preferably 0.06 seconds or less, more preferably less than 0.06 seconds, Preferably it is 0.05 second or less. When the half crystallization time of the thermoplastic resin (B) at 25 ° C. exceeds 0.01 seconds, a difference from the half crystallization time of the thermoplastic resin (A) at 25 ° C. occurs, and the crimped fibers are crimped. Can increase the sex.

The melt flow rate (MFR) of the thermoplastic resin (B) is preferably 10 g / 10 min or more, more preferably 30 g / 10 min or more, and preferably 500 g / 10 min or less.
The melt flow rate (MFR) is measured by a measurement method defined in JIS K7210, and is measured under conditions of a temperature of 230 ° C. and a load of 2.16 kg.

Using the differential scanning calorimeter (DSC) of the thermoplastic resin (B), the highest end of the melting endotherm curve obtained by holding at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. The melting point (Tm-D) defined as the peak top of the peak observed on the side is preferably 120 ° C. or higher, more preferably 130 ° C. or higher, still more preferably 140 ° C. or higher, and preferably 200 ° C. or lower. More preferably, it is 180 degrees C or less, More preferably, it is 170 degrees C or less.

Although the said thermoplastic resin (B) will not be specifically limited if the above-mentioned requirements are satisfied, it is preferable that it is a polypropylene resin. The polypropylene resin may be a propylene homopolymer or a copolymer, but is preferably a propylene homopolymer using a so-called metallocene catalyst having a narrow molecular weight distribution. In the case of a copolymer, the copolymerization ratio of propylene units is 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and 90 mol% or more. It is more preferable that it is 95 mol% or more. Examples of the copolymerizable monomer include ethylene, α-olefins having 2 or 4 to 20 carbon atoms such as 1-butene, 1-pentene, 1-hexene, 1-octene and 1-decene, methyl acrylate, etc. Acrylic acid ester, vinyl acetate, and the like are mentioned, and a propylene homopolymer is preferable from the viewpoint of moldability.
The thermoplastic resin (B) may contain a polypropylene resin polymerized using a catalyst (for example, a Ziegler-Natta catalyst) other than the metallocene catalyst. These may be used alone or in combination of two or more.
Specific examples include a propylene-based resin containing a peroxide.

Examples of commercially available propylene homopolymers include the “NOVATEC ^™ PP” series (for example, “NOVATEC SA03”) (manufactured by Nippon Polypro Co., Ltd.). Moreover, as a commercial item of the propylene homopolymer containing the peroxide polymerized using a catalyst other than the metallocene catalyst, “Moplen” series (for example, “Moplen HP461Y”) (manufactured by Lyondell Basell); PP3155 ( For example, trade name, manufactured by ExxonMobil Chemical Co., Ltd.).
As a commercial item of the polypropylene resin polymerized using the metallocene catalyst, “Metocene” series (for example, “Metocene MF650Y”) (manufactured by Lyondell Basell) and the like can be exemplified.
From the viewpoint of adjusting the viscosity, a polypropylene resin polymerized using a metallocene catalyst is preferable.

The content of the thermoplastic resin (B) in the second component is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, when the second component is 100% by mass. More preferably, it is 80 mass% or more, Preferably it is 99 mass% or less, More preferably, it is 97 mass% or less, More preferably, it is 95 mass% or less.

[Thermoplastic resin (C)]
The thermoplastic resin (C) used in this embodiment has a longer half crystallization time at 25 ° C. than that of the thermoplastic resin (B), preferably 0.06 seconds or more, more preferably more than 0.06 seconds.
When the half crystallization time of the thermoplastic resin (C) at 25 ° C. is 0.06 seconds or more, the half crystallization time of the first component at 25 ° C. and the half crystallization time of the second component at 25 ° C. And the crimpability of the crimped fiber can be further increased.

The melt flow rate (MFR) of the thermoplastic resin (C) is preferably 10 g / 10 min or more, more preferably 500 g / 10 min or more, and preferably 5000 g / 10 min or less. When the MFR is 10 g / 10 min or more, the difference between the MFR of the first component and the MFR of the second component can be further increased, and the crimpability of the crimped fiber can be further increased.
The melt flow rate (MFR) is measured by a measurement method defined in JIS K7210, and is measured under conditions of a temperature of 230 ° C. and a load of 2.16 kg.

Using the differential scanning calorimeter (DSC) of the thermoplastic resin (C), the highest end of the melting endotherm curve obtained by holding at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. The melting point (Tm-D) defined as the peak top of the peak observed on the side is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and preferably 100 ° C. or lower. If the melting point (Tm-D) of the thermoplastic resin (C) is 50 ° C. or higher, the difference between the melting point (Tm-D) of the first component and the melting point (Tm-D) of the second component is more Can be bigger.

The weight average molecular weight (Mw) of the thermoplastic resin (C) is preferably 30,000 or more, and preferably 150,000 or less, more preferably 60,000 or less.

The molecular weight distribution (Mw / Mn) of the thermoplastic resin (C) is preferably less than 3.0, more preferably 2.5 or less, and still more preferably 2.3 or less. If the molecular weight distribution of the thermoplastic resin (C) is within the above range, stickiness in the fiber obtained by spinning is suppressed.

Said weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) are calculated | required by a gel permeation chromatography (GPC) measurement. The weight average molecular weight is a polystyrene equivalent weight average molecular weight measured with the following apparatus and conditions, and the molecular weight distribution is a value calculated from the number average molecular weight (Mn) measured in the same manner and the above weight average molecular weight.
<GPC measurement device>
Column: “TOSO GMHHR-H (S) HT” manufactured by Tosoh Corporation
Detector: RI detection for liquid chromatogram "WATERS 150C" manufactured by Waters Corporation
<Measurement conditions>
Solvent: 1,2,4-trichlorobenzene Measurement temperature: 145 ° C
Flow rate: 1.0 mL / min Sample concentration: 2.2 mg / mL
Injection volume: 160 μL
Calibration curve: Universal Calibration
Analysis program: HT-GPC (Ver.1.0)

In the thermoplastic resin (C), a melting endotherm obtained by using a differential scanning calorimeter (DSC) and holding the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. The melting endotherm (ΔHD) obtained from the curve is preferably 0 J / g or more, more preferably 10 J / g or more, still more preferably 20 J / g or more, and preferably 80 J / g or less, more preferably Is 60 J / g or less, more preferably 40 J / g or less.
In this embodiment, the melting endotherm (ΔHD) is determined by using a differential scanning calorimeter (DSC), holding the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then increasing the temperature at 10 ° C./min. Obtain the area surrounded by the line containing the peak of the melting endotherm curve obtained by the process, the line on the low temperature side without any change in calorie, and the line on the high temperature side without any change in calorie (referred to as the base line) It is calculated by.

Although the said thermoplastic resin (C) will not be specifically limited if the above-mentioned requirements are satisfied, It is preferable that it is a polypropylene resin. The polypropylene resin may be a propylene homopolymer or a copolymer. From the viewpoint of suppressing stickiness, a polypropylene resin polymerized using a metallocene catalyst is preferred.
Examples of the propylene homopolymer include low molecular weight polypropylene, and preferred examples include L-MODU (manufactured by Idemitsu Kosan Co., Ltd.) and Moplen (manufactured by Lyondell Basell Co., Ltd.) synthesized using a metallocene catalyst. These may be used alone or in combination of two or more.
Further, when the polypropylene resin is a copolymer, the copolymerization ratio of propylene units exceeds 50 mol%, preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more, More preferably, it is 95 mol% or more. The copolymerizable monomer is at least one selected from the group consisting of ethylene and an α-olefin having 4 to 30 carbon atoms. Specific examples include ethylene, 1-butene, 1-pentene, 1-hexene, Examples include 1-octene and 1-decene.
When the polypropylene resin is a copolymer, the polypropylene resin contains at least one structural unit selected from the group consisting of ethylene and an α-olefin having 4 to 30 carbon atoms, more than 0 mol% and 20 mol% or less. It is preferable.

(Method for producing thermoplastic resin (C))
When the thermoplastic resin (C) is a polypropylene resin, the polypropylene resin can be produced using a metallocene catalyst as described in, for example, International Publication No. 2003/087172. In particular, those using a transition metal compound in which a ligand forms a cross-linked structure via a cross-linking group are preferred, and in particular, a transition metal compound that forms a cross-linked structure via two cross-linking groups and Metallocene catalysts obtained by combining promoters are preferred.

For example,
(I) General formula (I)

[Wherein, M represents a metal element of the Periodic Table Group 3-10 or the lanthanide series, E ¹ and E ² each represent a substituted cyclopentadienyl group, indenyl group, substituted indenyl group, a hetero cyclopentadienyl group A ligand selected from a substituted heterocyclopentadienyl group, an amide group, a phosphide group, a hydrocarbon group, and a silicon-containing group, which forms a cross-linked structure via A ¹ and A ² In addition, they may be the same or different from each other, X represents a σ-bonded ligand, and when there are a plurality of X, the plurality of X may be the same or different, and other X, E ¹ , E ² or Y may be cross-linked. Y represents a Lewis base, and when there are a plurality of Y, the plurality of Y may be the same or different, and may be cross-linked with other Y, E ¹ , E ² or X, and A ¹ and A ² are A divalent bridging group that binds two ligands, a hydrocarbon group having 1 to 20 carbon atoms, a halogen-containing hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, a germanium-containing group, a tin-containing group _{, -O -, - CO -,} - S -, - SO 2 -, - Se -, - NR 1 -, - PR 1 -, - P (O) R 1 -, - BR 1 - or -AlR ¹ - R ¹ represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a halogen-containing hydrocarbon group having 1 to 20 carbon atoms, which may be the same as or different from each other. q is an integer of 1 to 5 and represents [(valence of M) -2], and r represents an integer of 0 to 3. ]
And (ii) (ii-1) a compound capable of reacting with the transition metal compound of component (i) or a derivative thereof to form an ionic complex, and (ii-2) an aluminoxane And a polymerization catalyst containing at least one component selected from the group consisting of:

As the transition metal compound of the component (i), a ligand (1,2 ′) (2,1 ′) double-bridged transition metal compound is preferable. For example, (1,2′-dimethylsilylene) ( 2,1′-dimethylsilylene) -bis (3-trimethylsilylmethylindenyl) zirconium dichloride.

Specific examples of the compound of component (ii-1) include triethylammonium tetraphenylborate, tri-n-butylammonium tetraphenylborate, trimethylammonium tetraphenylborate, tetraethylammonium tetraphenylborate, methyl tetraphenylborate (tri- n-butyl) ammonium, benzyl tetraphenylborate (tri-n-butyl) ammonium, dimethyldiphenylammonium tetraphenylborate, triphenyl (methyl) ammonium tetraphenylborate, trimethylanilinium tetraphenylborate, methylpyridinium tetraphenylborate, tetra Benzylpyridinium phenylborate, methyl tetraphenylborate (2-cyanopyridinium), tetrakis (pentafluorophenyl) borate triethyl Ammonium, tetrakis (pentafluorophenyl) borate tri-n-butylammonium, tetrakis (pentafluorophenyl) triphenylammonium borate, tetrakis (pentafluorophenyl) borate tetra-n-butylammonium, tetrakis (pentafluorophenyl) tetraethylammonium borate Benzyl tetrakis (pentafluorophenyl) ammonium borate (tri-n-butyl), methyldiphenylammonium tetrakis (pentafluorophenyl) borate, triphenyl (methyl) ammonium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) boric acid Methylanilinium, tetrakis (pentafluorophenyl) dimethylanilinium borate, tetrakis (pentafluoro) Enyl) trimethylanilinium borate, methyl pyridinium tetrakis (pentafluorophenyl) borate, benzylpyridinium tetrakis (pentafluorophenyl) borate, methyl tetrakis (pentafluorophenyl) borate (2-cyanopyridinium), benzyl tetrakis (pentafluorophenyl) borate (2-cyanopyridinium), methyl tetrakis (pentafluorophenyl) borate (4-cyanopyridinium), triphenylphosphonium tetrakis (pentafluorophenyl) borate, tetrakis [bis (3,5-ditrifluoromethyl) phenyl] dimethylaniline borate Ferrocenium tetraphenylborate, silver tetraphenylborate, trityl tetraphenylborate, tetraphenylporphyrin tetramanganate , Tetrakis (pentafluorophenyl) borate ferrocenium, tetrakis (pentafluorophenyl) borate (1,1′-dimethylferrocenium), tetrakis (pentafluorophenyl) borate decamethylferrocenium, tetrakis (pentafluorophenyl) borate Silver, tetrakis (pentafluorophenyl) trityl borate, tetrakis (pentafluorophenyl) lithium borate, tetrakis (pentafluorophenyl) sodium borate, tetrakis (pentafluorophenyl) borate tetraphenylporphyrin manganese, silver tetrafluoroborate, silver hexafluorophosphate And silver hexafluoroarsenate, silver perchlorate, silver trifluoroacetate, silver trifluoromethanesulfonate, and the like.

Examples of the aluminoxane as the component (ii-2) include known chain aluminoxanes and cyclic aluminoxanes.

Trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, dimethylaluminum chloride, diethylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, dimethylaluminum fluoride, diisobutylaluminum hydride, diethylaluminum hydride, ethylaluminum sesquichloride, etc. A polypropylene resin may be produced by using together the organoaluminum compound.

The content of the thermoplastic resin (C) in the second component is preferably 1% by mass or more, more preferably 3% by mass or more, when the second component is 100% by mass from the viewpoint of improving crimpability. The amount is preferably 5% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and still more preferably 20% by mass or less. When the content of the thermoplastic resin (C) in the second component is 1% by mass or more, the fibers can be made thin, and the flexibility of the nonwoven fabric is improved as the elastic modulus of the fibers decreases.

In addition, the content of the thermoplastic resin (C) in the total of the thermoplastic resin (A), the thermoplastic resin (B), and the thermoplastic resin (C) is preferably 1 from the viewpoint of improving crimpability. % Or more, more preferably 2% or more, still more preferably 5% or more, and preferably 50% or less, more preferably 30% or less, still more preferably 20% or less.

In the crimped fiber of the present embodiment, any additive can be blended with at least one of the first component and the second component within a range that does not impair the effects of the present embodiment. Specific examples of additives include foaming agents, crystal nucleating agents, anti-glare stabilizers, UV absorbers, light stabilizers, heat stabilizers, antistatic agents, mold release agents, flame retardants, synthetic oils, waxes, electrical properties Improver, anti-slip agent, anti-blocking agent, viscosity modifier, anti-coloring agent, anti-fogging agent, lubricant, pigment, dye, plasticizer, softener, anti-aging agent, hydrochloric acid absorbent, chlorine scavenger, antioxidant And anti-adhesive agents.

In addition, the crimped fiber of the present embodiment preferably has a mass ratio of the first component containing the thermoplastic resin (A) and the second component containing the thermoplastic resin (B) and the thermoplastic resin (C). 9 to 1: 1 to 9, more preferably 7 to 3: 3 to 7. When the mass ratio between the first component and the second component is within the above range, the crimped nonwoven fabric exhibits crimpability and extensibility.

Examples of crimped fibers according to the present embodiment include side-by-side type fibers, core-sheath type fibers, and eccentric core-sheath type fibers, and side-by-side type fibers are preferable.

As a result of intensive analysis by the present inventors, in the crimped fiber of the present embodiment, depending on the spinning conditions, the component containing the thermoplastic resin (A), preferably the component containing the polyethylene resin, is inside the crimp. It has been found that there are two cases: a case where the component is located in the crimp, and a case where the component containing the thermoplastic resin (B), preferably the component containing the polypropylene resin is located inside the crimp.
The mechanism by which such a phenomenon occurs is not necessarily clear, but is presumed as follows.
The mechanism will be described assuming that the thermoplastic resin (A) is a polyethylene resin and the thermoplastic resin (B) is a polypropylene resin.
First, if the thermoplastic resin (C) is not added, the spinning speed and spinnability are not improved, so that the spinning speed does not increase and spinning can be performed only at a low speed.
When the spinning speed is low, when the polyethylene resin is cooled and solidified (crystallized), the density becomes higher than that of the polypropylene resin, so that the shrinkage ratio with the polypropylene resin is different. As described above, when the fiber is crimped by the difference in shrinkage rate between the two components, a polyethylene resin having a higher shrinkage rate is positioned inside the crimp.
On the other hand, it is presumed that orientation crystallization also contributes as a dominant factor of crimping under conditions where the spinning speed is sufficiently high. In the case of a composite fiber of a polypropylene resin and a polyethylene resin, it is known that the orientation state of molecules and crystals of the polypropylene resin is higher than the orientation state of molecules and crystals of the polyethylene resin. Textile Engineering "Vol. 55, No. 5 (2002), P. 236-242). This is considered to indicate that when a strong molecular orientation of a certain level or more is applied, a phenomenon that the polypropylene resin crystallizes faster than the polyethylene resin occurs.

When the thermoplastic resin (C) is added, the spinnability is improved and the spinning speed can be increased. When the spinning speed is high, the polypropylene resin solidifies faster than the polyethylene resin when it is cooled and solidified (crystallized), so that there is a difference in the solidification speed with the polyethylene resin. When the difference in shrinkage between the two components due to this causes the fiber to shrink, the polypropylene resin having a higher shrinkage is positioned inside the crimp.
Such a phenomenon can have a strong influence when a resin in a semi-molten state immediately after being discharged from the die forms crimped fibers. In other words, when the spinning speed is sufficiently high, the polypropylene resin is crystallized and fixed before the polyethylene resin, and at that time, the polyethylene resin in a semi-molten state is solidified while being relaxed. May be located outside. On the other hand, when the spinning speed is slow, it takes only a weak molecular orientation below a certain level, so the original crystallization speed is the dominant factor, and the polyethylene resin is inside the crimp and the polypropylene resin is outside the crimp. Will be located.
Not only when the spinning speed is high, but also when the discharge amount is small, when the resin temperature is low, when the flowability of the resin is low, and when the resin contains a large amount of high molecular weight components, etc. It can be said that since the molecular orientation is strongly applied, there is a high possibility that the polypropylene resin will be inside the crimp.
Polypropylene resins are not only contracted by crystallization but also contracted by the force of molecular chains that are stretched while being entangled during spinning to be released from stretching and return to their original state. Therefore, unlike a polyethylene resin, in the case of a polypropylene resin, the shrinkage ratio increases as the drawing force applied during spinning increases. Even when the shrinkage rate exceeds the shrinkage rate due to the crystallization of the polyethylene resin, the dominant factor for crimping the fiber changes, and the polypropylene resin having a higher shrinkage rate is located inside the crimp.

In addition, when the crimp fiber of this embodiment is a side-by-side type fiber, as resin which comprises the inner side of the crimp in the said crimp fiber, from the component and thermoplastic resin (A) containing a thermoplastic resin (A) The component which consists of, the component which contains a thermoplastic resin (B), and the component which consists of a thermoplastic resin (B) may be sufficient.

[Manufacture of crimped fibers]
As a manufacturing method of the crimped fiber of this embodiment, an example of the manufacturing method of the side-by-side type crimped fiber is shown below.
Side-by-side crimped fibers are obtained by melt-extruding at least two component resins using separate extruders and extruding them from a special spinneret as disclosed in US Pat. No. 3,671,379, for example. It is manufactured by a melt spinning method in which a molten resin melt-extruded from separate extruders is fused and discharged to form a fiber, and then cooled and hardened. Here, in the above process, the higher the spinning speed, the higher the crimpability of the obtained side-by-side crimped fiber, which is preferable.
In addition, in the manufacturing method of the side-by-side type crimped fiber in the present embodiment, a desired fiber can be manufactured without a post-processing step such as heating and stretching after spinning, but if necessary, post-processing is performed. For example, the crimping ratio of the fibers may be increased by heating at 100 to 150 ° C., stretching by 1.2 to 5 times, or a combination thereof.

In the crimped fiber of the present embodiment, the fineness calculated by the measurement method shown below is preferably 0.5 denier or more, and more preferably 0.8 denier, from the viewpoint of balance with the texture, flexibility, and strength of the nonwoven fabric. More preferably, it is 2.5 denier or less, more preferably 2.0 denier or less. The fineness of the crimped fiber is calculated by the following measuring method.

[Fineness measurement]
The fibers in the nonwoven fabric were observed using a polarizing microscope, the average value (d) of 100 randomly selected fiber diameters was measured, and the density of the resin (ρ = 900,000 g / m ³ ) was used to determine the nonwoven fabric. Calculate the fineness of the sample from the following formula.
Fineness (denier) = ρ × π × (d / 2) ² × 9000

In the crimped fiber of the present embodiment, the number of crimps is preferably 2/25 mm or more, more preferably 5/25 mm or more, still more preferably 10/25 mm or more, and even more preferably 13/25 mm or more, more More preferably, it is 15 pieces / 25 mm or more.
In the crimped fiber of this embodiment, the crimp rate is preferably 1.5% or more, more preferably 3% or more, still more preferably 5% or more, still more preferably 7% or more, and even more preferably 9 % Or more.
The number of crimps and the crimp rate can be measured by the method described in the examples.

<Nonwoven fabric>
The nonwoven fabric of this embodiment consists of the above-mentioned crimped fiber. As described above, the nonwoven fabric is small in fineness and excellent in spinning stability even under molding conditions where yarn breakage tends to occur. Moreover, the nonwoven fabric of this embodiment may be a multilayer nonwoven fabric formed by laminating two or more layers. In that case, from the viewpoint of surface smoothness, it is preferable that at least one layer of the nonwoven fabric constituting the outer layer of the multilayer nonwoven fabric is a nonwoven fabric composed of the above-described crimped fibers.

<Nonwoven Fabric Manufacturing Method>
The manufacturing method of the nonwoven fabric of this embodiment is not specifically limited, A conventionally well-known method is employable. Hereinafter, the spunbond method will be shown as an example.
Usually, in the spunbond method, the melt-kneaded resin composition is spun, stretched, opened to form continuous long fibers, and the continuous long fibers are continuously deposited on the moving collection surface in a continuous process, A nonwoven fabric is produced by entanglement. In this method, a nonwoven fabric can be produced continuously, and since the fibers constituting the nonwoven fabric are continuous continuous fibers that are drawn, the strength is high. As the spunbond method, a conventionally known method can be adopted. For example, fibers are produced by extruding a molten polymer from a large nozzle having several thousand holes or a small nozzle group having, for example, about 40 holes. can do. After exiting the nozzle, the molten fiber is cooled by a cross-flow chilled air system, then pulled away from the nozzle and drawn by high velocity air. There are usually two types of air attenuation methods, both of which use the Venturi effect. In the first method, the filament is drawn using a suction slot (slot drawing), and is performed at the nozzle width or the machine width. The second method draws the filament through a nozzle or suction gun. Filaments formed in this manner are collected on a screen (wire) or a pore-forming belt to form a web. Next, the web passes through the compression roll, then passes between the heated calender rolls, and the raised portion on one roll is bonded at a portion including an area of about 10% to 40% of the web to form a nonwoven fabric. To do.

[Fiber products]
Although it does not specifically limit as a fiber product using the nonwoven fabric of this embodiment, For example, the following fiber products can be mentioned. That is, disposable diaper members, elastic members for diaper covers, elastic members for sanitary products, elastic members for hygiene products, elastic tapes, adhesive plaster, elastic members for clothing, insulation materials for clothing, heat insulation materials for clothing, Protective clothing, hat, mask, gloves, supporter, elastic bandage, poultice base fabric, anti-slip base fabric, vibration absorber, finger sack, clean room air filter, electret processed electret filter, separator, insulation , Coffee bags, food packaging materials, automotive ceiling skin materials, soundproof materials, cushion materials, speaker dustproof materials, air cleaner materials, insulator skins, backing materials, adhesive nonwoven fabric sheets, door trims and other automotive parts, copying machine cleaning Various cleaning materials such as wood, carpet surface and backing materials, agricultural distribution, wood drain Shoes for members, bag for members such as sports shoes skin, industrial sealing material, mention may be made of the wiping material and sheets or the like.

Next, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

[Semi-crystallization time]
Using FLASH DSC (manufactured by METTLER TOLEDO), the measurement was performed by the following method.
(1) The sample was melted by heating at 230 ° C. for 2 minutes, then cooled to 25 ° C. at 2000 ° C./second, and the time change of the calorific value during the isothermal crystallization process at 25 ° C. was measured.
(2) When the integrated value of the calorific value from the start of isothermal crystallization to the completion of crystallization is 100%, the time from the start of isothermal crystallization until the integrated value of the calorific value becomes 50% is semi-crystallized. It was time.

[Melt flow rate (MFR)]
According to JIS K7210, the temperature of the thermoplastic resin (A) is 190 ° C. and the load is 2.16 kg, and the temperature of the thermoplastic resin (B) and the thermoplastic resin (C) is 230 ° C. and the load is 2.16 kg. It measured on condition of this.

[DSC measurement]
Using a differential scanning calorimeter (“DSC-7” manufactured by Perkin Elmer Co., Ltd.), 10 mg of a sample was held at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then heated at 10 ° C./min. The melting endotherm was obtained from the melting endothermic curve (ΔHD). Further, the melting point (Tm-D) was determined from the peak top of the peak observed on the highest temperature side of the obtained melting endotherm curve.
Note that the melting endotherm (ΔH−D) is a differential scanning calorimeter (manufactured by Perkin Elmer Co., Ltd.) with the line connecting the low temperature side point where there is no change in heat amount and the high temperature side point where there is no change in heat amount as the baseline. , “DSC-7”), and calculating the area surrounded by the line portion including the peak of the melting endothermic curve obtained by DSC measurement and the base line.

[Weight average molecular weight (Mw), molecular weight distribution (Mw / Mn) measurement]
The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) method to determine the molecular weight distribution (Mw / Mn). For the measurement, the following apparatus and conditions were used, and polystyrene-reduced weight average molecular weight and number average molecular weight were obtained. The molecular weight distribution (Mw / Mn) is a value calculated from these weight average molecular weight (Mw) and number average molecular weight (Mn).
<GPC measurement device>
Column: “TOSO GMHHR-H (S) HT” manufactured by Tosoh Corporation
Detector: RI detection for liquid chromatogram "WATERS 150C" manufactured by Waters Corporation
<Measurement conditions>
Solvent: 1,2,4-trichlorobenzene Measurement temperature: 145 ° C
Flow rate: 1.0 mL / min Sample concentration: 2.2 mg / mL
Injection volume: 160 μL
Calibration curve: Universal Calibration
Analysis program: HT-GPC (Ver.1.0)

(Production of propylene polymer (C1) [thermoplastic resin (C)])
In a stainless steel reactor with an internal volume of 20 L with a stirrer, n-heptane was 20 L / hr, triisobutylaluminum was 15 mmol / hr, dimethylanilinium tetrakispentafluorophenylborate, (1,2'-dimethylsilylene) The catalyst component obtained by previously contacting (2,1′-dimethylsilylene) -bis (3-trimethylsilylmethylindenyl) zirconium dichloride and triisobutylaluminum at a mass ratio of 1: 2: 20 with propylene is converted into zirconium. At 6 μmol / hr.
Propylene and hydrogen were continuously supplied at a polymerization temperature of 75 ° C. so that the gas phase hydrogen concentration was 24 mol% and the total pressure in the reactor was maintained at 1.0 MPa · G. The propylene polymer (C1) was obtained by adding an antioxidant to the obtained polymerization solution so that the content thereof was 1000 ppm by mass, and then removing n-heptane as a solvent.
The above-mentioned measurement was performed about the obtained propylene polymer (C1). The results are shown in Table 1.

(Production of propylene polymer (C2) [thermoplastic resin (C)])
In a stainless steel reactor with an internal volume of 20 L with a stirrer, n-heptane was 20 L / hr, triisobutylaluminum was 15 mmol / hr, dimethylanilinium tetrakispentafluorophenylborate, (1,2'-dimethylsilylene) The catalyst component obtained by previously contacting (2,1′-dimethylsilylene) -bis (3-trimethylsilylmethylindenyl) zirconium dichloride and triisobutylaluminum at a mass ratio of 1: 2: 20 with propylene is converted into zirconium. At 6 μmol / hr.
Propylene and hydrogen were continuously supplied at a polymerization temperature of 65 ° C. so that the gas phase hydrogen concentration was 8 mol% and the total pressure in the reactor was maintained at 1.0 MPa · G. The propylene polymer (C2) was obtained by adding an antioxidant to the obtained polymerization solution so that the content thereof was 1000 ppm by mass, and then removing n-heptane as a solvent.
The above-mentioned measurement was performed about the obtained propylene polymer (C2). The results are shown in Table 1.

In the following examples, the following raw materials were used.

<Thermoplastic resin (A)>
Ethylene-based resin (A1):
“ASPUN XUS 61800.52 LE” (Dow Chemical Co., density: 0.948 g / cm ³ )
Ethylene-based resin (A2):
"ULTZEX 20200J" (manufactured by Prime Polymer Co., Ltd.)
Ethylene resin (A3):
"ASPUN 6834" (manufactured by Dow Chemical)
Ethylene resin (A4):
"ASPUN 6850" (manufactured by Dow Chemical Company)
Ethylene-based resin (A5):
"Engage 8402" (manufactured by Dow Chemical)
Ethylene resin (A6):
“EVOLUE SP50500” (manufactured by Prime Polymer Co., Ltd.)
Table 2 shows the half-crystallization time, MFR and melting point (Tm-D) of the ethylene resins (A1), (A2), (A3), (A4), (A5) and (A6) measured by the above-mentioned method. Shown in

<Thermoplastic resin (B)>
Propylene homopolymer (B1):
"NOVATEC SA03" (manufactured by Nippon Polypro Co., Ltd.)
Propylene homopolymer (B2):
“PP3155” (manufactured by ExxonMobil Chemical)
Table 2 shows the half crystallization time, MFR, and melting point (Tm-D) of the propylene homopolymers (B1) and (B2) measured by the above method.

<Other ingredients>
Anti-slip agent: erucic acid amide, trade name: EA-10

Example 1
(Preparation of the first component)
As the thermoplastic resin (A), only the ethylene resin (A1) was used as the first component.

(Preparation of the second component)
80% by mass of the propylene homopolymer (B1) as the thermoplastic resin (B) and 20% by mass of the propylene polymer (C1) obtained in Production Example 1 as the thermoplastic resin (C), The second component was used.

(Manufacture of side-by-side crimped fibers and spunbond nonwoven fabrics composed of the crimped fibers)
The side-by-side crimped fiber was formed using a composite melt spinning machine bicomponent spinning apparatus having two extruders. The first component and the second component are melt-extruded at a resin temperature of 240 ° C. using separate single-screw extruders, and 54 kg per single hole from a side-by-side composite nozzle with a nozzle diameter of 0.60 mm (1795 holes). The melted resin was discharged at a speed of / h so that the mass ratio of the first component: second component was 50:50 and spun to obtain side-by-side crimped fibers. The obtained side-by-side crimped fiber is sucked at an ejector pressure of 5.0 kg / cm ² while being cooled with air having a cooling temperature of 12.5 ° C. and a wind speed of 0.6 m / sec, and is moved to the moving net surface. I collected it. The fiber bundle collected on the net surface was embossed at a linear pressure of 40 N / mm with a hot roll having a calendar temperature of 110 ° C./110° C. and wound around a take-up roll.

Example 2
In Example 1, the first component was changed to a composition composed of 98% by mass of ethylene resin (A1) and 2% by mass of erucamide, and the second component was 78% by mass of propylene homopolymer (B1). Side-by-side crimped fibers and nonwoven fabric were obtained in the same manner as in Example 1 except that the composition was changed to 20% by mass of the propylene polymer (C1) and 2% by mass of erucic acid amide.

Example 3
In Example 1, the first component was changed from the ethylene resin (A1) to the ethylene resin (A2), the ejector pressure was changed to 4.5 kg / cm ² , and the calendar temperature was changed to 100 ° C./100° C. In the same manner as in Example 1, side-by-side crimped fibers and nonwoven fabric were obtained.

Comparative Example 1
In Example 1, except that the second component was changed to a composition consisting of 100% by mass of the propylene homopolymer (B1), the ejector pressure was changed to 2.0 kg / cm ² , and the calendar temperature was changed to 100 ° C./100° C. Produced side-by-side crimped fibers and nonwoven fabric in the same manner as in Example 1.

The following measurements and evaluations were performed on the side-by-side crimped fibers and nonwoven fabric obtained in each example. The results are shown in Table 3.

[Measurement of basis weight]
A mass of 20 cm × 20 cm of the obtained nonwoven fabric was measured, and a basis weight (gsm) was measured.

[Measurement of fineness]
The fibers in the nonwoven fabric were observed using a polarizing microscope, the average value (d) of 100 randomly selected fiber diameters was measured, and the density of the resin (ρ = 900,000 g / m ³ ) was used to determine the nonwoven fabric. The fineness of the sample was calculated from the following equation.
Fineness (denier) = ρ × π × (d / 2) ² × 9000

[Tensile test]
From the obtained nonwoven fabric, a test piece having a length of 150 mm and a width of 50 mm was sampled in the machine direction (MD) and the direction perpendicular to the machine direction (TD). Tensile tester (manufactured by Shimadzu Corporation, Autograph AG-I) was used to set the initial length _{L 0} to 100 mm, and stretched at a tensile speed of 300 mm / min, to measure the strain and load at elongation process The maximum strength in the process until the nonwoven fabric breaks was defined as the strength of the nonwoven fabric.

[Handometer test]
A test piece having a length of 200 mm and a width of 200 mm was sampled from the obtained nonwoven fabric. The test piece was set on a 1/4 inch wide slit so as to be perpendicular to the slit, and the position of 67 mm (1/3 of the test piece width) from the side of the test piece was pushed 8 mm with a penetrator blade. The resistance value at this time was measured to evaluate the flexibility of the test piece. The feature of this measuring method is that the test piece slips slightly on the test table, and the combined force of the friction force generated thereby and the resistance force (flexibility) at the time of pushing is measured. It shows that the softness | flexibility of a nonwoven fabric is so favorable that the value of the resistance value obtained by the measurement is small.

[Measurement of static friction coefficient]
From the obtained nonwoven fabric, test pieces having a length of 220 mm × width of 100 mm and length of 220 mm × width of 70 mm were sampled in the machine direction (MD) and the direction perpendicular to the machine direction (TD). Static friction coefficient measurement tester (Toyo Seiki Seisakusho Co., Ltd., "Friction measuring machine AN type") Put two non-woven fabrics on the base and place a 1,000g weight on it to set the inclination of the base. The angle was changed at a speed of 2.7 degrees / minute, and the angle when the nonwoven fabric slipped 10 mm was measured. The static friction coefficient was calculated from the weight (1,000 g) of the weight and the angle when the nonwoven fabric slipped 10 mm.
In addition, it shows that textures, such as a touch feeling of a nonwoven fabric, are so favorable that the value of a static friction coefficient is small.

[Measurement of bulkiness]
A specimen having a length of 50 mm and a width of 50 mm was sampled from the obtained nonwoven fabric. Ten test pieces were stacked, a 1.9 g metal plate was placed on the stacked test pieces, and the thickness of the stacked test pieces was measured. It shows that it is a bulky nonwoven fabric, so that the numerical value of thickness is high.

(Measurement of crimp number)
It measured using the automatic crimp elastic modulus measuring apparatus according to the measuring method of the crimp number prescribed | regulated to JISL1015: 2010. One fiber was extracted from the sample on cotton before embossing so that the fiber was not tensioned, and the length when an initial load of 0.18 mN / tex was applied to a 25 mm sample was measured. The number of crimps was counted, and the number of crimps per 25 mm was obtained. It shows that it is a fiber and nonwoven fabric with high crimp property, so that there are many crimp numbers.

(Measurement of crimp rate)
About 10 cm of the obtained side-by-side crimped fiber was collected from a take-up roll, one fiber was separated from the bundled yarn, and the number of turns per 1 mm was measured with a microscope. Ten measurement samples were used, and the average value was used as the crimp rate. The higher the value of the crimp ratio, the more the fiber is crimped, and the more bulky fiber / nonwoven fabric product is obtained.

The side-by-side crimped fiber of the present embodiment can be thinned, and the nonwoven fabric made of the crimped fiber is bulky, highly crimpable, and excellent in flexibility and smoothness. .

Example 4
(Preparation of the first component)
As the thermoplastic resin (A), only the ethylene resin (A3) was used as the first component.

(Preparation of the second component)
80% by mass of the propylene homopolymer (B2) as the thermoplastic resin (B) and 20% by mass of the propylene polymer (C1) obtained in Production Example 1 as the thermoplastic resin (C), The second component was used.

(Manufacture of side-by-side crimped fibers)
A side-by-side crimped fiber was obtained by spinning in the same manner as in Example 1 except that the number of holes in the side-by-side composite nozzle was 6800 holes and the molten resin was discharged at a speed of 265 kg / h per single hole.

(Manufacture of spunbond nonwoven fabric composed of side-by-side crimped fibers)
The obtained side-by-side crimped fiber was sucked at a cabin pressure of 6,300 Pa while being cooled at a cooling temperature of 20 ° C., and collected on the moving net surface. The fiber bundle collected on the net surface was embossed at a linear pressure of 60 N / mm with a hot roll having a calendar temperature of 140 ° C./130° C., and wound around a take-up roll.

Comparative Example 2
Side-by-side crimped fibers were obtained in the same manner as in Example 4 except that the propylene homopolymer (B2) was 100% by mass as the second component. Moreover, the nonwoven fabric was obtained like Example 4 except having changed the pressure of the cabin pressure into 3,400 Pa.

The above measurement and evaluation were performed on the side-by-side crimped fibers and the nonwoven fabric obtained in Example 4 and Comparative Example 2. The results are shown in Table 4.

The nonwoven fabric composed of the side-by-side crimped fibers of Example 4 has a good texture such as flexibility and touch feeling as compared to the nonwoven fabric composed of the side-by-side crimped fibers of Comparative Example 2 that does not contain the thermoplastic resin (C). Met.

Example 5
(Preparation of the first component)
As the thermoplastic resin (A), only the ethylene resin (A3) was used as the first component.

(Manufacture of side-by-side crimped fibers)
A side-by-side crimped fiber was obtained by spinning in the same manner as in Example 1 except that the number of holes in the side-by-side composite nozzle was 6800 holes and the molten resin was discharged at a rate of 220 kg / h per single hole.

(Manufacture of spunbond nonwoven fabric composed of side-by-side crimped fibers)
The obtained side-by-side crimped fibers were sucked at a cabin pressure of 6,000 Pa while being cooled at a cooling temperature of 20 ° C. and collected on the moving net surface. Next, using three consecutive ovens, the temperature of each oven was heated under the conditions of 125 ° C., 133 ° C., and 133 ° C., and the fiber bundle collected on the net surface was partially heat-sealed.

Comparative Example 3
Side-by-side crimped fibers were obtained in the same manner as in Example 5 except that the propylene homopolymer (B2) was 100% by mass as the second component. Moreover, the nonwoven fabric was obtained like Example 5 except having changed the pressure of the cabin pressure into 3,400 Pa.

The side-by-side crimped fibers and nonwoven fabric obtained in Example 5 and Comparative Example 3 were evaluated by the above-described measurements for fineness, tensile test, handometer test, and bulkiness. The results are shown in Table 5.

The nonwoven fabric composed of the side-by-side crimped fibers of Example 5 is superior in flexibility and thicker than the nonwoven fabric composed of the side-by-side crimped fibers of Comparative Example 3 that does not contain the thermoplastic resin (C). We were able to.

Example 6
(Preparation of the first component)
As the thermoplastic resin (A), only the ethylene resin (A4) was used as the first component.

(Manufacture of side-by-side crimped fibers)
The side-by-side crimped fiber was formed using a composite melt spinning machine bicomponent spinning apparatus having two extruders. The first component and the second component are melt-extruded at a resin temperature of 230 ° C. using separate single-screw extruders, and 43 kg per single hole from a side-by-side composite nozzle having a nozzle diameter of 0.60 mm (1795 holes). The ejector pressure is increased while the molten resin is spun by discharging at a speed of / h so that the mass ratio of the first component to the second component is 50:50 and cooled with air at a wind speed of 0.6 m / sec. A side-by-side crimped fiber was obtained by suction at 0 kg / cm ² .

Example 7
In Example 6, the first component was changed from ethylene resin (A4) to ethylene resin (A5), and the ejector pressure was changed to 4.0 kg / cm ^2. A type crimped fiber was obtained.

Example 8
In Example 6, the first component was changed from the ethylene resin (A4) to the ethylene resin (A6), and the ejector pressure was changed to 2.5 kg / cm ^2. A type crimped fiber was obtained.

Example 9
In Example 6, the side-by-side type was used in the same manner as in Example 6 except that the first component was changed to a composition consisting of 50% by mass of ethylene resin (A1) and 50% by mass of ethylene resin (A6). A crimped fiber was obtained.

Example 10
In Example 6, the first component is changed from the ethylene resin (A4) to the ethylene resin (A1), and the second component is produced as 95% by mass of the propylene homopolymer (B1) and the thermoplastic resin (C). Side by side type in the same manner as in Example 6 except that the composition was changed to 5% by mass of the propylene polymer (C2) obtained in Example 2 and the ejector pressure was changed to 2.0 kg / cm ^2. A crimped fiber was obtained.

Example 11
In Example 10, the second component was changed to a composition consisting of 90% by mass of the propylene homopolymer (B1) and 10% by mass of the propylene-based polymer (C2). Side-by-side crimped fibers were obtained.

Example 12
In Example 10, except that the second component was changed to a composition comprising 80% by mass of the propylene homopolymer (B1) and 20% by mass of the propylene-based polymer (C2), the same procedure as in Example 10 was performed. Side-by-side crimped fibers were obtained.

Example 13
In Example 12, the mass ratio of the first component and the second component was changed to 30:70, and the ejector pressure was changed to 2.5 kg / cm ^2. A crimped fiber was obtained.

Example 14
In Example 10, the second component was changed to a composition consisting of 95% by mass of the propylene homopolymer (B1) and 5% by mass of the propylene polymer (C1), and the ejector pressure was adjusted to 2.5 kg / cm ² . Side-by-side crimped fibers were obtained in the same manner as in Example 10 except that the changes were made.

Example 15
In Example 14, the second component was changed to a composition consisting of 90% by mass of the propylene homopolymer (B1) and 10% by mass of the propylene-based polymer (C1). Side-by-side crimped fibers were obtained.

Comparative Example 4
(Preparation of the first component)
As the thermoplastic resin (A), only the ethylene resin (A6) was used as the first component.

(Preparation of the second component)
As the thermoplastic resin (B), only the propylene homopolymer (B1) was used as the second component.

(Manufacture of side-by-side crimped fibers)
The side-by-side crimped fiber was formed using a composite melt spinning machine bicomponent spinning apparatus having two extruders. The first component and the second component are melt-extruded at a resin temperature of 230 ° C. using separate single-screw extruders, and 43 kg per single hole from a side-by-side composite nozzle having a nozzle diameter of 0.60 mm (1795 holes). The molten resin was discharged at a speed of / h so that the mass ratio of the first component: second component was 50:50, but spinning could not be performed.

Comparative Example 5
In Example 9, the second component was changed to a composition composed of 100% by mass of the propylene homopolymer (B1), and the ejector pressure was changed to 1.5 kg / cm ² in the same manner as in Example 9. Side-by-side crimped fibers were obtained.

The side-by-side crimped fibers obtained in Examples 6 to 15 and Comparative Example 5 were measured and evaluated as described above. The results are shown in Table 6.

[Observation method of side-by-side crimped fibers]
The side-by-side crimped fiber placed on the slide glass was fixed using a quick-drying synthetic encapsulant (manufactured by Merck Co., Ltd., Entellan), and covered with a cover glass for observation. For the observation, an optical microscope (manufactured by OLYMPAS, BX51) was used, and the fibers were observed in a dark field mode and an observation magnification of 200 times.

Example 16
In Example 1, the propylene homopolymer (B1) was 79.5% by mass, the second component was 20% by mass of the propylene polymer (C1) obtained in Production Example 1 as a thermoplastic resin (C), and phthalocyanine blue. Side by side in the same manner as in Example 1 except that the composition was changed to a composition comprising 0.5% by mass of a master batch (propylene compound, MFR: 48 g / 10 min) and the ejector pressure was changed to 3.0 kg / cm ^2. A type crimped fiber was obtained. When the crimped fiber obtained by an optical microscope was observed to confirm the crimped direction, the outer side of the crimped fiber was a first component containing an ethylene resin (A1), and the inner side of the crimped fiber was a propylene homopolymer ( It was found to be a second component containing B1) and a propylene polymer (C1) (FIG. 1).

Example 17
In Example 16, side-by-side crimped fibers were obtained in the same manner as in Example 16 except that the ejector pressure was changed to 2.5 kg / cm ² . When the crimped direction of the obtained crimped fiber was confirmed, the outer side of the crimped fiber was the first component containing the ethylene resin (A1), and the inner side of the crimped fiber was the propylene homopolymer (B1) and the propylene-based heavy polymer. It was found to be a second component containing coalescence (C1) (FIG. 2).

Example 18
In Example 16, side-by-side crimped fibers were obtained in the same manner as in Example 16 except that the ejector pressure was changed to 2.0 kg / cm ² . When the crimped direction of the obtained crimped fiber was confirmed, the outer side of the crimped fiber was the first component containing the ethylene resin (A1), and the inner side of the crimped fiber was the propylene homopolymer (B1) and the propylene-based heavy polymer. It was found to be a second component containing coalescence (C1) (FIG. 3).

Example 19
In Example 16, side-by-side crimped fibers were obtained in the same manner as in Example 16 except that the ejector pressure was changed to 1.5 kg / cm ² . When the crimped direction of the obtained crimped fiber was confirmed, the outer side of the crimped fiber was the first component containing the ethylene resin (A1), and the inner side of the crimped fiber was the propylene homopolymer (B1) and the propylene-based heavy polymer. It was found to be the second component containing the coalescence (C1) (FIG. 4).

Example 20
In Example 16, side-by-side crimped fibers were obtained in the same manner as in Example 16 except that the ejector pressure was changed to 1.0 kg / cm ² . When the crimped direction of the obtained crimped fiber was confirmed, the outer side of the crimped fiber was a second component containing a propylene homopolymer (B1) and a propylene-based polymer (C1), and the inner side of the crimped fiber was ethylene-based. It turned out that it is the 1st component containing resin (A1) (FIG. 5).

Example 21
In Example 16, side-by-side crimped fibers were obtained in the same manner as in Example 16 except that the ejector pressure was changed to 0.5 kg / cm ² . When the crimped direction of the obtained crimped fiber was confirmed, the outer side of the crimped fiber was a second component containing a propylene homopolymer (B1) and a propylene-based polymer (C1), and the inner side of the crimped fiber was ethylene-based. It turned out that it is the 1st component containing resin (A1) (FIG. 6).

Images of the side-by-side crimped fibers obtained in Examples 16 to 21 observed with an optical microscope (200 times magnification) are shown in FIGS. 1 to 6, respectively. 1 to 6, it was confirmed that the side containing the particle component was the second component side to which the phthalocyanine blue masterbatch was added, and the crimped fiber curve was reversed inside and outside due to the difference in ejector pressure. . From this fact, a nonwoven fabric excellent in the balance of texture, flexibility and strength of the nonwoven fabric is expected by changing the crimped components inside and outside the fiber.

Claims

One component of the crimped fiber contains a thermoplastic resin (A), and the other component contains a thermoplastic resin (B) and a thermoplastic resin (C),
The half crystallization time of the thermoplastic resin (A) at 25 ° C. is shorter than the half crystallization time of the thermoplastic resin (B) at 25 ° C., and the half crystallization time of the thermoplastic resin (C) at 25 ° C. Which is longer than the half crystallization time at 25 ° C. of the thermoplastic resin (B).
The crimped fiber according to claim 1, wherein a half-crystallization time of the thermoplastic resin (A) at 25 ° C is 0.01 seconds or less.
The crimped fiber according to claim 1 or 2, wherein a half-crystallization time of the thermoplastic resin (B) at 25 ° C exceeds 0.01 seconds and is 0.06 seconds or less.
The crimped fiber according to any one of claims 1 to 3, wherein a half-crystallization time of the thermoplastic resin (C) at 25 ° C exceeds 0.06 seconds.
The melt flow rate (MFR) measured under conditions of a temperature of 190 ° C. and a load of 2.16 kg in accordance with JIS K7210 of the thermoplastic resin (A) is 1 g / 10 min to 70 g / 10 min. Crimped fiber according to any one of the above.
The melt flow rate (MFR) measured under conditions of a temperature of 230 ° C. and a load of 2.16 kg in accordance with JIS K7210 of the thermoplastic resin (B) is 10 g / 10 min or more and 500 g / 10 min or less. Crimped fiber according to any one of the above.
The melt flow rate (MFR) measured under conditions of a temperature of 230 ° C. and a load of 2.16 kg in accordance with JIS K7210 of the thermoplastic resin (C) is 10 g / 10 min or more and 5000 g / 10 min or less. Crimped fiber according to any one of the above.
Using the differential scanning calorimeter (DSC) of the thermoplastic resin (A), the highest end of the melting endotherm curve obtained by holding at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. The crimped fiber according to any one of claims 1 to 7, wherein a melting point (Tm-D) defined as a peak top of a peak observed on the side is 90 ° C or higher and 135 ° C or lower.
Using the differential scanning calorimeter (DSC) of the thermoplastic resin (B), the highest end of the melting endotherm curve obtained by holding at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. The crimped fiber according to any one of claims 1 to 8, wherein a melting point (Tm-D) defined as a peak top of a peak observed on the side is 120 ° C or higher and 200 ° C or lower.
Using the differential scanning calorimeter (DSC) of the thermoplastic resin (C), the highest end of the melting endotherm curve obtained by holding at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. The crimped fiber according to any one of claims 1 to 9, wherein a melting point (Tm-D) defined as a peak top of a peak observed on the side is 50 ° C or higher and 100 ° C or lower.
The crimped fiber according to any one of claims 1 to 10, wherein the thermoplastic resin (A) is a polyethylene resin.
The crimped fiber according to any one of claims 1 to 11, wherein the thermoplastic resin (B) is a polypropylene resin.
The crimped fiber according to claim 12, wherein the thermoplastic resin (B) is a propylene homopolymer.
In the thermoplastic resin (C), a melting endotherm obtained by using a differential scanning calorimeter (DSC) and holding the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. The crimped fiber according to any one of claims 1 to 13, wherein a melting endotherm (ΔHD) obtained from the curve is 0 J / g or more and 80 J / g or less.
The crimped fiber according to any one of claims 1 to 14, wherein a molecular weight distribution (Mw / Mn) of the thermoplastic resin (C) is less than 3.0.
The content of the thermoplastic resin (C) in the total of the thermoplastic resin (A), the thermoplastic resin (B), and the thermoplastic resin (C) is 1% or more and 50% or less. The crimped fiber according to any one of 1 to 15.
The crimped fiber according to any one of claims 1 to 16, wherein the crimped fiber is a side-by-side type fiber.
The crimped fiber according to claim 17, wherein a resin constituting the inside of the crimp in the crimped fiber is a side-by-side fiber containing the thermoplastic resin (A).
The crimped fiber according to claim 17, wherein a resin constituting the inside of the crimp in the crimped fiber is a side-by-side fiber made of the thermoplastic resin (A).
The crimped fiber according to claim 17, wherein a resin constituting the inside of the crimp in the crimped fiber is a side-by-side fiber containing the thermoplastic resin (B).
The crimped fiber according to claim 17, wherein a resin constituting the inside of the crimp in the crimped fiber is a side-by-side type fiber made of the thermoplastic resin (B).
A nonwoven fabric comprising the crimped fiber according to any one of claims 1 to 21.
A multilayer nonwoven fabric obtained by laminating two or more layers, wherein at least one layer is the nonwoven fabric according to claim 22.