JP2005060896A - Conjugated fiber, method for producing the same and nonwoven fabric using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conjugated fiber that has flexibility, spinnability (drafting properties), a moderate level of heat resistance and unstickiness, provide a method for producing the same and provide nonwoven fabric using the conjugated fiber. <P>SOLUTION: As one component of the conjugated fiber, is used (A) a resin material including a ethylene (co)polymer that satisfies the following: (a) a density of 0.86 to 0.97 g/cm<SP>3</SP>, (b) a melt flow rate of 2 to 200 g/10 min, (c) a molecular weight distribution (Mw/Mn) of 1.5 to 4.5, (d) the difference between T<SB>25</SB>and T<SB>75</SB>obtained from the integrated elution curve of the elution temperature - elution volume curve according to TREF and density d satisfies the relation: T<SB>75</SB>-T<SB>25</SB>≤ -670×d+644. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a composite fiber such as a core-sheath fiber that is excellent in spinnability, stretchability, flexibility, and adhesiveness, and has no stickiness, a method for producing a composite fiber that can easily be obtained, and a nonwoven fabric using the composite fiber .

Conventionally, as a material of a composite fiber such as a core-sheath fiber, a polyolefin having high crystallinity because of excellent spinnability and stretchability, for example, a polyester resin, polypropylene, high-density polyethylene or the like as a core material, low-density polyethylene, The core-sheath fiber which uses a linear low density polyethylene and a high density polyethylene as a sheath material is proposed.
However, these conventional core-sheath fibers are hard and have insufficient texture and flexibility when used for nonwoven fabrics. Therefore, the fabric obtained from such fibers should be used for disposable items such as disposable diapers; athletic clothing such as wristbands; clothing that touches the skin directly with medical items such as bandages and gauze. There was a need for improvement.

In order to improve the flexibility of these core-sheath fibers, an attempt is made to use a linear low-density polyethylene obtained by a branched low-density polyethylene or Ziegler-type catalyst obtained by a high-pressure radical polymerization method, which is excellent in flexibility, as the sheath material. It has also been made.
However, linear low density polyethylene obtained with branched low density polyethylene and Ziegler type catalysts have the disadvantage of poor adhesion at low temperatures, low compatibility with core materials, poor workability, and spinnability. It was also bad, so it had a problem that it was difficult to make fibers. In addition, linear low density polyethylene obtained by using branched low density polyethylene or Ziegler type catalyst has a relatively wide molecular weight distribution and contains a lot of low molecular weight components. Was.

  In order to solve these problems, fibers made of a linear low density polyethylene obtained by a metallocene catalyst are disclosed in JP-T-8-503525 (Patent Document 1) and JP-A-8-509784 ( Patent Document 2) proposes. The linear low density polyethylene obtained by the metallocene catalyst has relatively high crystallinity, excellent stretchability, and narrow molecular weight distribution, so that the resulting fiber is less sticky.

However, although the linear low density polyethylene obtained by the metallocene catalyst has improved flexibility as compared with the composite fiber obtained from polypropylene and high density polyethylene (for example, JP 2002-88582 A: Patent Document 3). Further, a material having good flexibility and drafting properties is demanded.
Japanese National Patent Publication No. 8-503525 JP-T 8-509784 JP 2002-88582 A

  Therefore, the object of the present invention is to have flexibility and spinnability (draft property) equivalent to or higher than the linear low density polyethylene obtained by these metallocene catalysts, moderate heat resistance, and stickiness. An object of the present invention is to provide a composite fiber, a production method thereof, and a nonwoven fabric using the same.

The composite fiber of the present invention contains (A) 100 to 20% by mass of an ethylene (co) polymer that satisfies the following requirements (a) to (d) and (B) 0 to 80% by mass of another polyolefin resin. It consists of at least two components of a resin material and a thermoplastic resin (C) having a melting point higher than that of the resin material, and has a fineness of 0.2 to 30 denier.
(A) a density of 0.86 to 0.97 g / cm ³ ,
(B) a melt flow rate of 2 to 200 g / 10 minutes,
(C) molecular weight distribution (Mw / Mn) is 1.5 to 4.5,
(D) Difference between temperature T _{25 at} which 25% of the elution is obtained from the integral elution curve of the elution temperature-elution amount curve by continuous temperature rising elution fractionation method (TREF) and temperature T _{75 at} which 75% of the elution is eluted T ₇₅ −T ₂₅ and density d satisfy the relationship of the following (Formula 1) (Formula 1) T ₇₅ −T ₂₅ ≦ −670 × d + 644

The (A) ethylene (co) polymer preferably further satisfies the following requirement (e).
(E) The difference between the temperature T _{25 at} which 25% of the total elution is obtained from the integral elution curve of the elution temperature-elution amount curve by the continuous temperature rising elution fractionation method (TREF) and the temperature T _{75 at} which 75% of the total is eluted. T ₇₅ -T ₂₅ and density d satisfy the following relationship (Formula 2) (Formula 2) When d <0.950 g / cm ³
T ₇₅ −T ₂₅ ≧ −300 × d + 285
When d ≧ 0.950 g / cm ³
T ₇₅ -T ₂₅ ≧ 0

Further, the (A) ethylene (co) polymer further satisfies the following requirements (f) and (g): (A1) an ethylene (co) polymer, or further the following (h) and (i): It is desirable that it is an (A2) ethylene (co) polymer that satisfies the requirements.
(F) The amount of orthodichlorobenzene (ODCB) soluble component X (mass%), density d, and melt flow rate (MFR) at 25 ° C. satisfy the relationship of the following (formula 3) and (formula 4) (formula 3) When d−0.008log MFR ≧ 0.93, X <2.0
(Formula 4) When d−0.008 log MFR <0.93 X <9.8 × 10 ³ × (0.9300−d + 0.008 log MFR) ² +2.0
(G) There are a plurality of peaks in the elution temperature-elution amount curve by the continuous temperature rising elution fractionation method (TREF). (H) One peak in the elution temperature-elution amount curve by the continuous temperature elution fractionation method (TREF). (I) It has one or more melting point peaks, and the highest melting point T _ml and density d satisfy the relationship of the following (formula 5) (formula 5) T _ml ≧ 150 × d-19

The (A2) ethylene (co) polymer preferably further satisfies the following requirement (j).
(J) Melt tension (MT) and melt flow rate (MFR) satisfy the following (formula 6) (formula 6) logMT ≦ −0.572 × logMFR + 0.3
The (A) ethylene (co) polymer is preferably produced in the presence of a catalyst containing at least an organic cyclic compound having a conjugated double bond and a transition metal compound of Group 4 of the periodic table. .

The halogen concentration in the resin material is desirably 10 ppm or less.
In the composite fiber of the present invention, the resin material containing (A) 100 to 20% by mass of an ethylene (co) polymer and (B) 0 to 80% by mass of another polyolefin resin is a sheath, and the resin material It is desirable that the (C) thermoplastic resin having a higher melting point is a core-sheath composite fiber having a core part.

Moreover, the manufacturing method of the composite fiber of this invention is the (A) ethylene (co) polymer 100-20 mass% which satisfies the requirements of said (a) to (d), and (B) other polyolefin resin 0-80. And at least two components of (C) thermoplastic resin having a melting point higher than that of the resin material are spun from the same die, spun to a fineness of 0.5 to 80 denier, and stretched as desired. The fineness is 0.2 to 30 denier.
Moreover, the nonwoven fabric of this invention is a nonwoven fabric formed using the conjugate fiber of this invention.

Since the conjugate fiber of the present invention is made of a resin material containing (A) an ethylene (co) polymer that satisfies the requirements (a) to (d) described above, it has excellent flexibility and is not sticky. And the fabric obtained from such a composite fiber is very good in touch compared with the conventional one.
Further, if the (A) ethylene (co) polymer further satisfies the requirement (e), the flexibility is maintained, and the spinnability and stretchability are further improved.
Further, if the (A) ethylene (co) polymer further satisfies the above requirements (f) and (g) (A1) ethylene (co) polymer, the stickiness is further improved and the stretchability is improved. , Heat resistance and rigidity are further improved.
Moreover, since the conjugate fiber of the present invention is excellent in spinnability, stretchability, compatibility with the core material, etc., it has good workability and can be easily manufactured.

Hereinafter, the present invention will be described in detail.
[(A) Ethylene (co) polymer]
The (A) ethylene (co) polymer in the present invention is obtained by homopolymerizing ethylene or copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms, preferably 3 to 12 carbon atoms. It is.
Examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene and 1-dodecene. Further, the total content of these α-olefins is usually 30 mol% or less, preferably 3 to 20 mol% or less.

The (a) density of the (A) ethylene (co) polymer is in the range of 0.86 to 0.97 g / cm ³ , and preferably in the range of 0.91 to 0.96 g / cm ³ . If the density is less than 0.86 g / cm ³ , spinnability is difficult and fiberization may be difficult. Moreover, when the density exceeds 0.97 g / cm ³ , it is difficult to produce industrially.

  (A) The ethylene (co) polymer (b) melt flow rate (hereinafter referred to as MFR) is in the range of 2 to 200 g / 10 minutes, preferably 5 to 150 g / 10 minutes, more preferably 10 to 10 minutes. The range is 100 g / min. If the MFR is less than 2 g / 10 minutes, the spinnability may be difficult. Moreover, when MFR exceeds 200 g / 10min, there exists a possibility that it may become a thing with a difficulty in ductility.

(A) The ethylene (co) polymer (c) molecular weight distribution (Mw / Mn) is in the range of 1.5 to 4.5, more preferably 2.0 to 4.0, and even more preferably 2. It is in the range of 5-3.0. If Mw / Mn is less than 1.5, the spinnability may be difficult. When Mw / Mn exceeds 4.5, stickiness occurs and there is a possibility that the stretchability and the like may be difficult.
Here, the molecular weight distribution (Mw / Mn) of the ethylene (co) polymer is determined by gel permeation chromatography (GPC) to obtain a mass average molecular weight (Mw) and a number average molecular weight (Mn), and a ratio (Mw) / Mn).

(A) The ethylene (co) polymer is, for example, as shown in FIG. 1, (d) 25% of the total obtained from an integrated elution curve of elution temperature-elution amount curve by continuous temperature rising elution fractionation method (TREF). The difference T ₇₅ -T ₂₅ and the density d between the temperature T _{25 at} which elution occurs and the temperature T _{75 at} which 75% of the total elution evaporate satisfy the following relationship (Formula 1).
(Formula 1) T ₇₅ −T ₂₅ ≦ −670 × d + 644
When T ₇₅ -T ₂₅ and the density d do not satisfy the relationship of the above (formula 1), there is a possibility that flexibility, spinnability, stretchability, and the like may be difficult.

The measuring method of TREF is as follows. First, a sample is added to ODCB to which an antioxidant (for example, butylhydroxytoluene) is added so that the sample concentration becomes 0.05 mass%, and heated and dissolved at 140 ° C. 5 ml of this sample solution is injected into a column filled with glass beads, cooled to 25 ° C. at a cooling rate of 0.1 ° C./min, and the sample is deposited on the surface of the glass beads. Next, the sample is sequentially eluted while increasing the column temperature at a constant rate of 50 ° C./hr while flowing ODCB through the column at a constant flow rate. At this time, the concentration of the sample eluted in the solvent is continuously detected by measuring the absorption with respect to the wave number of 2925 cm ⁻¹ of the asymmetric stretching vibration of methylene with an infrared detector. From this value, the concentration of the ethylene (co) polymer in the solution is quantitatively analyzed to determine the relationship between the elution temperature and the elution rate.
According to the TREF analysis, since a change in elution rate with respect to a temperature change can be continuously analyzed with a very small amount of sample, it is possible to detect a relatively fine peak that cannot be detected by a fractionation method.

In addition, (A) the ethylene (co) polymer further has a temperature T at which 25% of the total obtained from the integral elution curve of the elution temperature-elution amount curve by (e) continuous temperature rising elution fractionation method (TREF) is eluted. the difference T ₇₅ -T ₂₅ and the density d of the temperature T _{75 to 25} and the total 75% elutes, it is preferable to satisfy the following relationship (equation 2).
(Formula 2) When d <0.950 g / cm ³
T ₇₅ −T ₂₅ ≧ −300 × d + 285
When d ≧ 0.950 g / cm ³
T ₇₅ -T ₂₅ ≧ 0
When T ₇₅ -T ₂₅ and the density d satisfy the relationship of the above (formula 2), the fiber has a good balance between flexibility and heat resistance.

  (A) The ethylene (co) polymer further satisfies the requirements of (f) and (g) described later. (A1) The ethylene (co) polymer, or the requirements of (h) and (i) described further below. (A2) It is preferable that it is either ethylene (co) polymer.

(A1) The amount (% by mass) of the ODCB soluble content at 25 ° C. and the density d and MFR of the ethylene (co) polymer satisfy the relationship of the following (formula 3) and (formula 4): And
(Formula 3) When d−0.008log MFR ≧ 0.93,
X <2.0
(Formula 4) When d−0.008 log MFR <0.93,
X <9.8 × 10 ³ × (0.9300−d + 0.008logMFR) ² +2.0
Preferably,
If d−0.008log MFR ≧ 0.93,
X <1.0
d-0.008 log MFR <0.93,
X <7.4 × 10 ³ × (0.9300−d + 0.008 log MFR) ² +2.0
And more preferably,
If d−0.008log MFR ≧ 0.93,
X <0.5
d-0.008 log MFR <0.93,
X <5.6 × 10 ³ × (0.9300−d + 0.008 log MFR) ² +2.0
Satisfied with the relationship.

Here, the amount X of soluble ODCB at 25 ° C. is measured by the following method. A sample of 0.5 g is heated with 20 ml of ODCB at 135 ° C. for 2 hours to completely dissolve the sample, and then cooled to 25 ° C. This solution is allowed to stand at 25 ° C. overnight, and then filtered through a Teflon (registered trademark) filter to collect the filtrate. The filtrate, which is a sample solution, measures the absorption peak intensity around 2925 cm ⁻¹ of the asymmetric stretching vibration of methylene using an infrared spectrometer, and calculates the sample concentration using a calibration curve prepared in advance. From this value, the amount of soluble ODCB at 25 ° C. is obtained.

  The ODCB soluble component at 25 ° C. is a highly branched component and a low molecular weight component contained in the ethylene copolymer, which causes a decrease in heat resistance and fiber stickiness, and causes sanitary problems and blocking. It is desirable that this content is small. The amount of ODCB solubles is affected by the α-olefin content and molecular weight of the entire copolymer, ie, density and MFR. Accordingly, the fact that the density and the amount of soluble components of MFR and ODCB satisfying the above relationship indicate that the α-olefin contained in the entire copolymer is less unevenly distributed.

  The (A1) ethylene (co) polymer has a plurality of peaks in the elution temperature-elution amount curve obtained by (g) continuous temperature rising elution fractionation method (TREF). It is particularly preferable that the peak temperature on the high temperature side of the plurality of peak temperatures exists between 85 ° C and 100 ° C. The (A1) ethylene (co) polymer in which this peak exists has a high melting point and an increased crystallinity, so that the heat resistance and rigidity are improved and the stretchability is excellent.

Here, as shown in FIG. 2, (A1) ethylene (co) polymer has a special peak having substantially a plurality of peaks in the elution temperature-elution amount curve obtained by the continuous temperature rising elution fractionation method (TREF). This is an ethylene-α-olefin copolymer.
On the other hand, the ethylene copolymer of FIG. 3 is an ethylene-α-olefin copolymer having substantially one peak in the elution temperature-elution amount curve obtained by the continuous temperature rising elution fractionation method (TREF). This is an ethylene copolymer produced by a typical metallocene catalyst.

  As shown in FIG. 4, the (A2) ethylene (co) polymer in the present invention has one peak in the elution temperature-elution amount curve by (h) continuous temperature rising elution fractionation method (TREF). The (A2) ethylene (co) polymer having one peak in the elution temperature-elution amount curve by TREF can be obtained with a good balance between flexibility and heat resistance.

Further, the (A2) ethylene (co) polymer in the present invention has (i) 1 to 2 melting points, and the highest melting point T _ml and density d satisfy the relationship of the following (formula 5). To do.
(Formula 5) T _ml ≧ 150 × d-19
When the melting point T _m1 and the density d satisfy the relationship of the above (formula 5), heat resistance is obtained.

Among the (A2) ethylene (co) polymers, ethylene (co) polymers that satisfy the following requirement (j) are preferable.
(J) Melt tension (MT) and melt flow rate (MFR) satisfy the relationship of the following (formula 6) (formula 6) logMT ≦ −0.572 × logMFR + 0.3
When MT and MFR satisfy the relationship of the above (Formula 6), moldability such as spinnability is improved.

  Here, although (A2) the ethylene (co) polymer has one TREF peak as shown in FIG. 4, the conventional ethylene copolymer based on a metallocene catalyst is the above (formula 2). Is not distinguished from the conventional ethylene copolymer by a metallocene catalyst.

  The (A) ethylene (co) polymer in the present invention is not particularly limited to a catalyst, a production method and the like as long as the specific parameters are satisfied, but at least an organic cyclic compound having a conjugated double bond and a periodic rule. A linear ethylene (co) polymer obtained by homopolymerizing ethylene or copolymerizing ethylene and an α-olefin in the presence of a catalyst containing a transition metal compound of Table 4 is preferable. . Such a linear ethylene (co) polymer has a narrow molecular weight distribution and composition distribution compared to a linear low density polyethylene by a Ziegler type catalyst, so it has excellent mechanical properties, spinnability and stretchability, and is not sticky. It is a polymer with little heat resistance.

The (A) ethylene (co) polymer is particularly preferably produced by a catalyst obtained by mixing the following compounds a1 to a4.
a1: formula ^{_{Me 1 R 1 p R 2 q}} (OR 3) r X 1 compound represented by the _4-pqr (wherein Me ¹ represents zirconium, titanium, hafnium, R ¹ and R ³ are carbon atoms 1 to 24 hydrocarbon groups, R ² represents 2,4-pentanedionato ligand or derivative thereof, benzoylmethanato ligand, benzoylacetonate ligand or derivative thereof, X ¹ represents a halogen atom , P, q, and r are integers satisfying the ranges of 0 ≦ p ≦ 4, 0 ≦ q ≦ 4, 0 ≦ r ≦ 4, and 0 ≦ p + q + r ≦ 4, respectively)
a2: a compound represented by the general formula Me ² R ⁴ _m (OR ⁵ ) _n X ² _zmn (wherein Me ² is a group element in the periodic table 1, ^2, 12, 13 and R ⁴ and R ⁵ are each a carbon number) 1 to 24 hydrocarbon groups, X ² represents a halogen atom or a hydrogen atom (however, when X ² is a hydrogen atom, Me ² is limited to a group 13 element in the periodic table), and z is a valence of Me ² And m and n are integers satisfying the ranges of 0 ≦ m ≦ z and 0 ≦ n ≦ z, and 0 ≦ m + n ≦ z)
a3: Organocyclic compound having conjugated double bond a4: Modified organoaluminum oxy compound and / or boron compound containing Al—O—Al bond

Of general formula ^{_{Me 1 R 1 p R 2 q}} (OR 3) r X 1 compound represented by the _4-pqr of the catalyst component a1, Me ¹ represents zirconium, titanium, hafnium, these transition metals The type is not limited, and a plurality of types can be used, but it is particularly preferable that zirconium is included. R ¹ and R ³ are each a hydrocarbon group having 1 to 24 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms. Specifically, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group and butyl group; alkenyl groups such as vinyl group and allyl group; phenyl group, tolyl group, xylyl group, mesityl group, indenyl group and naphthyl group And aryl groups such as benzyl group, trityl group, phenethyl group, styryl group, benzhydryl group, phenylbutyl group, and neofoyl group. These may be branched. R ² represents a 2,4-pentanedionate ligand or a derivative thereof, a benzoylmethanato ligand, a benzoylacetonato ligand or a derivative thereof. X ¹ represents a halogen atom such as fluorine, iodine, chlorine and bromine. p, q, and r are integers satisfying the ranges of 0 ≦ p ≦ 4, 0 ≦ q ≦ 4, 0 ≦ r ≦ 4, and 0 ≦ p + q + r ≦ 4, respectively.

Examples of the compound represented by the general formula of the catalyst component a1 include tetramethylzirconium, tetraethylzirconium, tetrabenzylzirconium, tetrapropoxyzirconium, tripropoxymonochlorozirconium, tetraethoxyzirconium, tetrabutoxyzirconium, tetrabutoxytitanium, tetrabutoxy Hafnium and the like are mentioned, and Zr (OR) ₄ compounds such as tetrapropoxyzirconium and tetrabutoxyzirconium are particularly preferred, and two or more of these may be used in combination. Specific examples of the 2,4-pentanedionato ligand or derivative thereof, benzoylmethanato ligand, benzoylacetonate ligand or derivative thereof include tetra (2,4-pentandionato) zirconium. , Tri (2,4-pentanedionato) chloride zirconium, di (2,4-pentandionato) dichloride zirconium, (2,4-pentandionato) trichloride zirconium, di (2,4-pentandionato) Diethoxide zirconium, di (2,4-pentanedionato) di-n-propoxide zirconium, di (2,4-pentandionato) di-n-butoxide zirconium, di (2,4-pentane) Diato) dibenzylzirconium, di (2,4-pentanedionate) dineoyl zirconium, tetra ( Benzoylmethanato) zirconium, di (dibenzoylmethanato) diethoxide zirconium, di (dibenzoylmethanato) di-n-propoxide zirconium, di (dibenzoylmethanato) di-n-butoxidezirconium, di (benzoyl) Acetonato) diethoxide zirconium, di (benzoylacetonato) di-n-propoxide zirconium, di (benzoylacetonato) di-n-butoxide zirconium and the like.

Said wherein Me ² in the general formula _{^{Me 2 R 4 m (OR 5}} ) n X 2 compound represented by _zmn catalyst component a2 shows the periodic table 1,2,12,13 group element, lithium, sodium, Potassium, magnesium, calcium, zinc, boron, aluminum and the like. R ⁴ and R ⁵ are each a hydrocarbon group having 1 to 24 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms. Specifically, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group and butyl group; alkenyl groups such as vinyl group and allyl group; phenyl group, tolyl group, xylyl group, mesityl group, indenyl group and naphthyl group And aryl groups such as benzyl group, trityl group, phenethyl group, styryl group, benzhydryl group, phenylbutyl group, and neofoyl group. These may be branched. X ² represents a halogen atom or hydrogen atom such as fluorine, iodine, chlorine and bromine. However, when X ² is a hydrogen atom, Me ² is limited to a group 13 element of the periodic table exemplified by boron, aluminum and the like. Z represents the valence of Me ² , and m and n are integers satisfying the ranges of 0 ≦ m ≦ z and 0 ≦ n ≦ z, respectively, and 0 ≦ m + n ≦ z.

  Examples of the compound represented by the general formula of the catalyst component a2 include organic lithium compounds such as methyllithium, ethyllithium, and butyllithium; organic compounds such as dimethylmagnesium, diethylmagnesium, butylethylmagnesium, methylmagnesium chloride, and ethylmagnesium chloride. Magnesium compounds; Organic zinc compounds such as dimethyl zinc and diethyl zinc; Organic boron compounds such as trimethylboron and triethylboron; Trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, trihexylaluminum, tridecylaluminum, diethylaluminum chloride , Ethylaluminum dichloride, ethylaluminum sesquichloride, diethylaluminum et Side, diethylaluminum hydride, and a derivative of an organic aluminum compounds such as diisobutylaluminum hydride.

  The organic cyclic compound having a conjugated double bond of the catalyst component a3 is cyclic, having one or more rings having 2 or more, preferably 2 to 4, more preferably 2 to 3 conjugated double bonds. A cyclic hydrocarbon compound having 4 to 24 carbon atoms, preferably 4 to 20 carbon atoms; the cyclic hydrocarbon compound is partially a hydrocarbon residue having 1 to 6 carbon atoms (typically having 1 to 12 alkyl groups or aralkyl groups) substituted with 2 or more, preferably 2 to 4 and more preferably 2 to 3 rings having 1 or 2 conjugated double bonds. An organosilicon compound having a cyclic hydrocarbon group having a total carbon number of 4 to 24, preferably 4 to 20; the cyclic hydrocarbon group is partially a hydrocarbon residue or alkali metal salt (sodium 1-6) Or lithium salt) The organosilicon compound is contained. Particularly preferred is one having a cyclopentadiene structure in any of the molecules.

  Suitable examples of the compound include cyclopentadiene, indene, azulene, or alkyl, aryl, aralkyl, alkoxy or aryloxy derivatives thereof. Moreover, the compound which these compounds couple | bonded (bridge | crosslinked) via the alkylene group (The carbon number is 2-8 normally, Preferably 2-3) is also used suitably.

The organosilicon compound having a cyclic hydrocarbon group can be represented by the following general formula.
A _L SiR _4-L
Here, A represents the cyclic hydrogen group exemplified by cyclopentadienyl group, substituted cyclopentadienyl group, indenyl group, and substituted indenyl group, and R represents methyl group, ethyl group, propyl group, isopropyl group, butyl group An alkyl group such as a group; an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group; an aryl group such as a phenyl group; an aryloxy group such as a phenoxy group; an aralkyl group such as a benzyl group; To 24, preferably 1 to 12 hydrocarbon residues or hydrogen, L is 1 ≦ L ≦ 4, preferably 1 ≦ L ≦ 3.

Specific examples of the organic cyclic hydrocarbon compound of component a3 include cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, propylcyclopentadiene, butylcyclopentadiene, 1,3-dimethylcyclopentadiene, 1-methyl-3-ethylcyclopentadiene. 1-methyl-3-propylcyclopentadiene, 1-methyl-3-butylcyclopentadiene, 1,2,4-trimethylcyclopentadiene, pentamethylcyclopentadiene, indene, 4-methyl-1-indene, 4,7- 5 to 24 carbon atoms such as dimethylindene, benzoindene, cycloheptatriene, methylcycloheptatriene, cyclooctatetraene, azulene, fluorene, methylfluorene, 1H-cyclopenta [l] phenanthrene. Examples include chloropolyene or substituted cyclopolyene, monocyclopentadienylsilane, biscyclopentadienylsilane, triscyclopentadienylsilane, monoindenylsilane, bisindenylsilane, and trisindenylsilane.
These compounds serving as ligands may be used alone or in combination. A plurality of complexes or catalysts having these as ligands may be combined.

  The modified organoaluminum oxy compound containing an Al—O—Al bond of the catalyst component a4 is obtained by reacting an alkylaluminum compound with water to obtain a modified organoaluminum oxy compound usually referred to as an aluminoxane. Usually, it contains 1 to 100, preferably 1 to 50 Al—O—Al bonds. The modified organoaluminum oxy compound may be linear or cyclic.

The reaction between organoaluminum and water is usually carried out in an inert hydrocarbon. As the inert hydrocarbon, aliphatic, alicyclic and aromatic hydrocarbons such as pentane, hexane, heptane, cyclohexane, benzene, toluene and xylene are preferable.
The reaction ratio (water / Al molar ratio) between water and the organoaluminum compound is usually 0.25 / 1 to 1.2 / 1, preferably 0.5 / 1 to 1/1.

As the boron compound of the catalyst component a4, borate or borane is used. Specific examples of the borate include tributylammonium tetrakis (o-fluorophenyl) borate, tributylammonium tetrakis (p-fluorophenyl) borate, tributylammonium tetrakis (m-fluorophenyl) borate, tributylammonium tetrakis (3,5-difluorophenyl) ) Borate, tributylammonium tetrakis (pentafluorophenyl) borate, dimethylanilinium tetrakis (o-fluorophenyl) borate, dimethylanilinium tetrakis (p-fluorophenyl) borate, dimethylanilinium tetrakis (m-fluorophenyl) borate, dimethyl Anilinium tetrakis (3,5-difluorophenyl) borate, dimethylanilinium tetrakis (pentaph Orophenyl) borate, trityltetrakis (o-fluorophenyl) borate, trityltetrakis (p-fluorophenyl) borate, trityltetrakis (m-fluorophenyl) borate, trityltetrakis (pentafluorophenyl) borate, tropiniumtetrakis (o-fluoro) Phenyl) borate, tropinium tetrakis (p-fluorophenyl) borate, tropinium tetrakis (m-fluorophenyl) borate, tropinium tetrakis (3,5-difluorophenyl) borate, tropinium tetrakis (pentafluorophenyl) borate It is done. Preferable examples include tributylammonium tetrakis (pentafluorophenyl) borate, dimethylanilinium tetrakis (pentafluorophenyl) borate, trityltetrakis (pentafluorophenyl) borate, and tropinium tetrakis (pentafluorophenyl) borate.
Specific examples of the borane compound include tris (o-fluorophenyl) borane, tris (p-fluorophenyl) borane, tris (m-fluorophenyl) borane, tris (3,5-difluorophenyl) borane, tris ( Pentafluorophenyl) borane, preferably tris (pentafluorophenyl) borane.

The catalyst may be used by mixing and contacting a1 to a4, but it is preferable to use the catalyst supported on an inorganic carrier and / or a particulate polymer carrier (a5).
Examples of the inorganic carrier and / or particulate polymer carrier (a5) include carbonaceous materials, metals, metal oxides, metal chlorides, metal carbonates or mixtures thereof, thermoplastic resins, thermosetting resins, and the like. Preferred as the inorganic carrier is a metal oxide (single oxide or double oxide).
Specific examples include SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ , B ₂ O ₃ , CaO, ZnO, BaO, ThO _2, or a mixture thereof, and SiO ₂ —Al ₂ O _3. SiO ₂ —V ₂ O ₅ , SiO ₂ —TiO ₂ , SiO ₂ —V ₂ O ₅ , SiO ₂ —MgO, SiO ₂ —Cr ₂ O _{3 and the} like. Among these, those containing as a main component at least one component selected from the group consisting of SiO ₂ and Al ₂ O ₃ are preferable.
As the organic compound, any of a thermoplastic resin and a thermosetting resin can be used. Specifically, particulate polyolefin, polyester, polyamide, polyvinyl chloride, poly (meth) acrylate, polystyrene, Examples include norbornene, various natural polymers, and mixtures thereof.

  The inorganic carrier and / or the particulate polymer carrier can be used as they are, but preferably, as a pretreatment, these carriers are contacted with an organoaluminum compound or a modified organoaluminum compound containing an Al—O—Al bond. After that, it can also be used as component a5.

(A) A method for producing an ethylene (co) polymer is produced by a gas phase polymerization method, a slurry polymerization method, a solution polymerization method, or the like that is substantially free of a solvent in the presence of the catalyst. In the state where the above are excluded, aliphatic hydrocarbons such as butane, pentane, hexane and heptane, aromatic hydrocarbons such as benzene, toluene and xylene, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane are exemplified. Produced in the presence or absence of an active hydrocarbon solvent. The polymerization conditions are not particularly limited, but the polymerization temperature is usually from 15 to 350 ° C., preferably from 20 to 200 ° C., more preferably from 50 to 110 ° C., and the polymerization pressure is usually from normal pressure to 70 kg / cm ^{2 in the} low-medium pressure method. G, preferably normal pressure to 20 kg / cm ² G, and usually 1500 kg / cm ² G or less in the high pressure method. The polymerization time is usually about 3 minutes to 10 hours, preferably about 5 minutes to 5 hours in the case of the low-medium pressure method. In the case of the high pressure method, it is usually 1 minute to 30 minutes, preferably about 2 minutes to 20 minutes. In addition, the polymerization is not particularly limited to a one-stage polymerization method, but also a two-stage or more multi-stage polymerization method in which polymerization conditions such as hydrogen concentration, monomer concentration, polymerization pressure, polymerization temperature, and catalyst are different from each other. A particularly preferable production method includes the method described in JP-A-5-132518.

(A) The ethylene (co) polymer is a halogen concentration of at most 10 ppm, preferably 5 ppm or less, more preferably substantially, by using a catalyst having no halogen such as chlorine among the above catalyst components. 2 ppm or less (ND: Non-Detect) which is not included in.
By using such a halogen-free ethylene (co) polymer such as chlorine, there is no need to use a conventional acid neutralizer (halogen absorber), and chemical stability and hygiene are excellent. In particular, it is possible to provide a fabric made of clean composite fibers that is suitably used for disposable diapers, medical supplies, and the like.

[(B) Other polyolefin resin]
In the present invention, (B) another polyolefin resin may be further blended. The (B) other polyolefin resin includes an ethylene (co) polymer different from the above-mentioned (A) ethylene (co) polymer, an ethylene (co) polymer obtained by radical polymerization, polypropylene, polybutene- 1, poly-4-methyl-pentene-1, ethylene-α-olefin copolymer rubber (EPR, EPDM, etc.) and the like. These can be blended up to 80% by mass or less, preferably 50% by mass or less, more preferably 30% by mass or less.

The ethylene (co) polymer different from (A) the ethylene (co) polymer does not satisfy the specific parameters defined by the above-mentioned (A) ethylene (co) polymer. As such an ethylene (co) polymer, ethylene (co) polymerized using a conventionally known Ziegler-type catalyst, Phillips catalyst, or metallocene-type catalyst (hereinafter referred to as a Ziegler-type catalyst or the like). A polymer is mentioned. Such an ethylene (co) polymer generally has a broader molecular weight distribution or composition distribution than the (A) ethylene (co) polymer, a density of 0.88 to 0.97 g / cm ³ , and an MFR of 1. Those in the range of ˜50 g / 10 min are preferred, and so-called very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE) are included.

The ethylene (co) polymer by a Ziegler type catalyst is a high density polyethylene (HDPE) and a medium density polyethylene (MDPE) having a density of 0.94 to 0.97 g / cm ³ , and a density of 0.91 to 0.94 g / cm ^{3. 3} linear low density polyethylene (LLDPE), and these MFRs are in the range of 1-100 g / 10 min, preferably 1-50 g / 10 min, more preferably 5-30 g / 10 min.

A very low density polyethylene (VLDPE) using a Ziegler type catalyst or the like has a density of 0.88 to less than 0.91 g / cm ³ , preferably 0.88 to 0.905 g / cm ³ , and an MFR of 1 to 100 g / 10 minutes. , Preferably in the range of 5-50 g / 10 min. The very low density polyethylene (VLDPE) exhibits intermediate properties between linear low density polyethylene (LLDPE) and ethylene-α-olefin copolymer rubber (EPR, EPDM). In addition, ultra-low density polyethylene (VLDPE) has a maximum peak temperature (Tm) by differential scanning calorimetry (DSC) of 60 ° C. or higher, preferably 100 ° C. or higher, and a boiling n-hexane insoluble content of 10% by mass or higher. Is a specific ethylene-α-olefin copolymer that is polymerized using a catalyst comprising a solid catalyst component containing at least titanium and / or vanadium and an organoaluminum compound, a metallocene catalyst, etc. It is a resin having both a high crystal part represented by density polyethylene (LLDPE) and an amorphous part represented by ethylene-α-olefin copolymer rubber. Such very low density polyethylene (VLDPE) is characterized by mechanical strength, heat resistance, etc., which are characteristics of linear low density polyethylene (LLDPE), and rubbery elasticity, which is a characteristic of ethylene-α-olefin copolymer rubber. In addition, low temperature impact resistance coexists in a well-balanced manner.

  The α-olefin of the ethylene-α-olefin copolymer by a Ziegler-type catalyst or the like has 3 to 12 carbon atoms, preferably 3 to 10 carbon atoms. Specifically, propylene, 1-butene, 4- Examples thereof include methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene and the like. Moreover, it is preferable that content of these alpha olefins is normally selected in 3-40 mol% in total.

  Examples of the ethylene (co) polymer obtained by the radical polymerization method include low density polyethylene (LDPE), ethylene-vinyl ester copolymer, ethylene and α, β-unsaturated carboxylic acid or derivatives thereof by high pressure radical polymerization method. And a copolymer thereof.

The MFR of the low density polyethylene (LDPE) is in the range of 2 to 200 g / 10 minutes, more preferably 5 to 150 g / 10 minutes. If it is this range, melt tension will become a suitable range and spinnability will improve. The density is in the range of 0.91 to 0.94 g / cm ³ , more preferably 0.912 to 0.935 g / cm ³ . Within this range, spinnability and stretchability are improved.

  The ethylene-vinyl ester copolymer is ethylene and vinyl propionate, vinyl acetate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl stearate based on ethylene produced by a high-pressure radical polymerization method. It is a copolymer with a vinyl ester monomer such as vinyl trifluoroacetate. Among these, vinyl acetate is particularly preferable. Further, a copolymer composed of 50 to 99.5% by mass of ethylene, 0.5 to 50% by mass of vinyl ester, and 0 to 49.5% by mass of other copolymerizable unsaturated monomers is preferable. In particular, the vinyl ester content is 3 to 30% by mass, preferably 5 to 25% by mass. The MFR of the ethylene-vinyl ester copolymer is in the range of 2 to 150 g / 10 minutes, more preferably 5 to 100 g / 10 minutes.

  Examples of the copolymer of ethylene and α, β-unsaturated carboxylic acid or a derivative thereof include ethylene-maleic anhydride copolymer, ethylene- (meth) acrylic acid or an alkyl ester copolymer thereof, and the like. As comonomers, maleic anhydride, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, acrylic acid n -Butyl, n-butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, glycidyl acrylate, glycidyl methacrylate, etc. it can. Among these, maleic anhydride and alkyl esters such as methyl (meth) acrylate and ethyl are particularly preferable. In particular, the content of (meth) acrylic acid ester is in the range of 3 to 30% by mass, preferably 5 to 25% by mass. The MFR of a copolymer of ethylene and an α, β-unsaturated carboxylic acid or derivative thereof is 2 to 150 g / 10 minutes, more preferably 5 to 100 g / 10 minutes.

Examples of polypropylene resins include homopolypropylene and propylene-ethylene copolymers. The density of the polypropylene resin is 0.89 to 0.91 g / cm ³ , and the MFR is 5 to 200 g / 10 minutes, preferably 10 to 150 g / 10 minutes. If it is this range, melt tension will become a suitable range and spinnability will improve.
Examples of the ethylene / α-olefin copolymer rubber include ethylene propylene rubber (EPR), ethylene-propylene-diene terpolymer (EPDM), and ethylene / butene-1 copolymer rubber.

  The type of (B) other polyolefin resin used in the present invention varies depending on the required properties depending on the application. Among these (B) other polyolefin resins, (A) from the point of imparting excellent spinnability, stretchability, compatibility with the core material, etc., to resin materials containing ethylene (co) polymers, high density polyethylene, Linear low density polyethylene, polypropylene resin and the like are preferably used.

[Resin material]
The resin material containing (A) ethylene (co) polymer in the present invention contains (A) 100 to 20% by mass of ethylene (co) polymer and 0 to 80% by mass of other polyolefin (B). Yes, preferably in the range of (A) 100 to 50% by mass of ethylene (co) polymer and 0 to 50% by mass of other polyolefin (B), more preferably (A) ethylene (co) polymer 100 to 70. It is the range of 0-30 mass% of other polyolefin (B) with a mass%. When the (A) ethylene (co) polymer is less than 20% by mass and the other polyolefin (B) exceeds 80% by mass, the heat-fusibility, the fusion strength and flexibility, and the texture are inferior.

  (A) Various additives, compounding agents, and fillers can be used for the resin material containing an ethylene (co) polymer as long as the characteristics of the resin material are not impaired. Specifically, antioxidants (heat stabilizers), ultraviolet absorbers (light stabilizers), antistatic agents, tackifiers, antifogging agents, flame retardants, lubricants (slip agents, antiblocking agents) , Colorants (dyes, pigments), and fragrances.

  (A) For the preparation of a resin material containing an ethylene (co) polymer, various commonly known methods for mixing resins can be used. Examples of the specific method include a method of mixing each component in a molten state, that is, a method using a generally used pressure kneader, roll, Banbury mixer, static mixer, screw type extruder, or the like. .

[(C) Thermoplastic resin]
(C) As the thermoplastic resin, a thermoplastic resin that is at least 10 ° C. higher than the melting point of the resin material containing the (A) ethylene (co) polymer or the (A) ethylene (co) polymer is selected. Specific examples of these thermoplastic resins include linear low density polyethylene, high density polyethylene, ultrahigh molecular weight polyethylene, polypropylene resin, poly-4-methyl-1-pentene resin and other α-carbon atoms having 4 or more carbon atoms. Polyolefin resins such as olefins alone or their alternating copolymers; polyester resins, polyamide resins, polycarbonate resins, polyphenylene resins (PPE), engineering plastics such as polyphenylene sulfide (PPS), etc. A combination with a polyolefin-based resin, a polyester-based resin, or a polyamide-based resin is preferable from the viewpoint of molding processability, handleability, performance, economy, versatility, and the like.

[Composite fiber]
The conjugate fiber of the present invention includes a bonded type, a core-sheath type, and a polydisperse type, and the core-sheath type is particularly preferable. In the composite fiber of the present invention, the resin material containing (A) 100 to 20% by mass of an ethylene (co) polymer and (B) 0 to 80% by mass of another polyolefin resin is a sheath, and the resin material The (C) thermoplastic resin having a higher melting point is preferably a core-sheath composite fiber that is a core part. These composite fibers are obtained by spinning by a known melt spinning method or the like and drawing as desired.
Molten resin temperature is 200-400 degreeC normally. The draw ratio is usually 2 to 15 times, preferably 2 to 10 times. An annealing process can be performed as needed.
The fineness of the conjugate fiber of the present invention is suitably used in the range of 0.2 to 30 denier, preferably 0.2 to 20 denier, more preferably 0.2 to 10 denier.

[Production method]
The composite fiber of the present invention is prepared by spinning at least two components of (A) a resin material containing an ethylene (co) polymer and (C) a thermoplastic resin having a higher melting point from the same die by a known melt spinning method or the like. Although it is obtained by drawing out and stretching if desired, it is preferably carried out by the following method.
That is, the two-component material of (A) a resin material containing an ethylene (co) polymer and a higher melting point (C) thermoplastic resin is usually in the range of a resin temperature of 150 to 400 ° C., preferably 200 to 350 ° C. Then, each is melt-extruded from an individual extruder, melt-spun from the same nozzle attached to the tip of the extruder, cooled with air and / or a refrigerant, and then stretched in a stretching process.

  The fineness at the time of melt spinning is 0.5 to 80 denier, preferably 1 to 60 denier. The spun fiber is cooled with air and / or with a refrigerant in a temperature range of 0 to 60 ° C, preferably 5 to 50 ° C, more preferably 5 to 45 ° C. Cooling is performed with a refrigerant such as air cooling or water cooling by installing a refrigerant tank such as a roll, water, or oil. As a cooling means, air cooling is preferable because it is simple and has good workability and efficiency.

  In the stretching step, the stretching ratio is usually 2 to 15 times, preferably 2 to 10 times, and more preferably 2 to 8 times. The stretching may be continuous multistage stretching or sequential stretching. Moreover, it is preferable to stretch after heating in the range of 60 to 150 ° C., preferably 80 to 130 ° C. before stretching.

Moreover, an annealing process or a crimping process can also be performed as needed.
Further, as described in JP-A-5-214609, JP-A-5-214609, JP-A-6-200442, and the like, an oil agent such as a sizing agent is applied at the time of cooling after spinning, and continuously In addition, the composite fiber of the present invention can be easily obtained by using a heated roll pair or the like in-line.
The fineness of the composite fiber thus obtained is in the range of 0.2 to 30 denier in terms of single yarn fineness, preferably in the range of 0.2 to 20 denier, and more preferably in the range of 0.2 to 10 denier.

In such a composite fiber, a resin material containing (A) an ethylene (co) polymer that satisfies the above-mentioned requirements (a) to (d) is used for the sheath as a material having high adhesiveness. Therefore, it is excellent in heat-fusibility and adhesion to the core material, and the fiber is excellent in flexibility and has no stickiness. And the fabric obtained from such a composite fiber has a good texture and a very good touch compared with the conventional one.
Further, in the method for producing a composite fiber, since a resin material containing (A) an ethylene (co) polymer excellent in spinnability and stretchability is used as the material, flexibility, spinnability (draft) Property), stretchability, and workability, and a composite fiber can be easily obtained.

[Nonwoven fabric]
The nonwoven fabric of the present invention is obtained from the above-mentioned composite fiber, and includes a random nonwoven fabric made of short fibers of the composite fiber, a background laminated nonwoven fabric, a random nonwoven fabric made of long fibers, a background laminated nonwoven fabric, and the like. In particular, the production method is not limited. The nonwoven fabric of the present invention includes a product made from a nonwoven fabric made of the conjugate fiber of the present invention and a processed product such as another woven fabric, nonwoven fabric or mat.
The nonwoven fabric obtained from the conjugate fiber of the present invention is suitably used for disposable articles such as disposable diapers; athletic clothing such as wristbands; and medical articles such as bandages and gauze that directly touch human skin. be able to.

EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated in more detail, this invention is not limited by these Examples.
The test method in this example is as follows.
[density]
Conforms to JIS K6922-2.
[MFR]
Conforms to JIS K6922-2.
[Mw / Mn]
GPC (Waters 150C type) was used, and ODCB at 135 ° C. was used as a solvent. The column used was Shodex HT806M.

[TREF]
With the column kept at 135 ° C., the sample was injected into the column and the temperature was lowered to 25 ° C. at 0.1 ° C./min. After the polymer was deposited on the glass beads, the column was heated under the following conditions. The polymer concentration eluted at each temperature was detected with an infrared detector. (Solvent: ODCB, flow rate: 1 ml / min, heating rate: 50 ° C./hr, detector: infrared spectrometer (wavelength 2925 cm ⁻¹ ), column: 0.8 cmφ × 12 cmL (packed with glass beads), sample concentration : 0.05% by mass)
[Measurement of T _ml by DSC]
A sheet having a thickness of 0.2 mm was formed by hot pressing, and a sample of about 5 mg was punched from the sheet. The sample was held at 230 ° C. for 10 minutes and then cooled to 0 ° C. at 2 ° C./min. Thereafter, the temperature was raised again to 170 ° C. at 10 ° C./min, and the temperature at the peak of the highest temperature peak that appeared was defined as the highest peak temperature T _ml .

[ODCB soluble content]
0.5 g of sample was added to 20 ml of ODCB and heated at 135 ° C. for 2 hours to completely dissolve the sample, and then cooled to 25 ° C. This solution was allowed to stand at 25 ° C. overnight and then filtered through a Teflon (registered trademark) filter to collect the filtrate. The absorption peak intensity in the vicinity of wave number 2925 cm ⁻¹ of the asymmetric stretching vibration of methylene in the filtrate as the sample solution was measured with an infrared spectrometer, and the sample concentration in the filtrate was calculated with a calibration curve prepared in advance. From this value, the ODCB soluble content at 25 ° C. was determined.

[Melt tension (MT)]
The stress when the molten polymer was stretched at a constant speed was determined by measuring with a strain gauge. The measurement sample was granulated into pellets and measured using an MT measuring device manufactured by Toyo Seiki Seisakusho. The orifice used has a hole diameter of 2.09 mmφ and a length of 8 mm. The measurement conditions are a resin temperature of 190 ° C., a cylinder lowering speed of 20 mm / min, and a winding speed of 15 m / min.
[Halogen concentration]
When measured by a fluorescent X-ray method and 10 ppm or more of chlorine was detected, this was used as an analytical value. When it was less than 10 ppm, it was measured with a TOX-100 type chlorine / sulfur analyzer manufactured by Dia Instruments Co., Ltd., and 2 ppm or less was considered to be substantially free of ND (non-detect).

The various components used in the examples are as follows.
(A) The ethylene (co) polymer was polymerized by the following method.
[(A1) ethylene (co) polymer]
(Preparation of solid catalyst)
To a catalyst preparation apparatus equipped with an electromagnetic induction stirrer, 1000 ml of toluene purified under nitrogen, 22 g of tetraethoxyzirconium (Zr (OEt) ₄ ), 75 g of indene and 88 g of methylbutylcyclopentadiene were added and tripropyl was maintained at 90 ° C. 100 g of aluminum was added dropwise over 100 minutes, and then reacted at the same temperature for 2 hours. After cooling to 40 ° C., 3200 ml of a toluene solution of methylalumoxane (concentration 2.5 mmol / ml) was added and stirred for 2 hours. Next, 2000 g of silica (Grace, # 952, surface area 300 m ² / g) preliminarily baked at 450 ° C. for 5 hours is added, stirred at room temperature for 1 hour, blown with nitrogen at 40 ° C., and dried under reduced pressure. A good solid catalyst was obtained.

(Gas phase polymerization)
Ethylene and 1-hexene were copolymerized at a polymerization temperature of 65 ° C. and a total pressure of 20 kgf / cm ² G using a continuous fluidized bed gas phase polymerization apparatus. The solid catalyst was continuously supplied, and ethylene, 1-hexene and hydrogen were supplied so as to maintain a predetermined molar ratio for polymerization to obtain an ethylene copolymer (A1a, A1b, A1c, A1d). The physical properties are shown in Table 1.

[Linear Low Density Polyethylene (LLDPE) and High Density Polyethylene (HDPE) with Commercial Ziegler Catalyst]
1) Density: 0.958 g / cm ³ , MFR: 19 g / 10 min, trade name: KL882H, manufactured by Nippon Polyolefin (abbreviation HD-1).
2) Density: 0.943 g / cm ³ , MFR: 19 g / 10 min, trade name: AM897A, manufactured by Nippon Polyolefin Co., Ltd. (abbreviation LL-1).
3) Density: 0.925 g / cm ³ , MFR: 20 g / 10 min, trade name: AM83NA, manufactured by Nippon Polyolefin Co., Ltd. (abbreviation LL-2).

[Examples 1 to 4]
100 parts by mass of each of the resins of ethylene copolymers (A1a), (A1b), (A1c), and (A1d) serving as the sheath were charged into the extruder A. High-density polyethylene (density: 0.958 g / cm ³ , MFR: 19 g / 10 min, melting point: 132 ° C., trade name: KL882H, manufactured by Nippon Polyolefin Co., Ltd.) or homopolypropylene (high density thermoplastic resin serving as the core) : 0.90 g / cm ³ , MFR: 18 g / 10 min, melting point: 162 ° C., trade name: PL802C, manufactured by Sun Allomer Co., Ltd.) 100 parts by mass were charged into Extruder B. Each resin was supplied from the respective extruders to the die part by the same mass of the two components under the following conditions.
Cylinder temperature: C1 / 250 ° C, C2 / 260 ° C, C3 / 270 ° C, C4 / 280 ° C, head temperature: P1 · P2 / 270 ° C, spin block temperature: SB1 · SB2 / 260 ° C.

The sheath part molten resin and the core part molten resin supplied to the die part and passed through the distribution plate were extruded from the same nozzle under the following conditions to produce core-sheath composite fibers shown in Table 2. The fineness reached was evaluated. The results are shown in Table 2.
Nozzle: 1.0φ × 20H (hole), cooling air temperature 20 ° C., take-up speed 400 m / min. Setting denier 3.3d / F (filament).
(Fine fineness)
Fineness per hole (denier, g / 9000 m) at the take-off speed (m / min).

Next, the raw fiber of the composite fiber was placed in a net-like mold of 155 mm × 215 mm and laminated (laminated raw cotton mass 2 g (60 g / m ² )). Under the conditions of wind speed of 5.6 m / sec and heating time of 5 sec, the composite fiber was thermally fused with the air-through method to produce a nonwoven fabric. The results of evaluation of the fusion strength, texture, etc. are shown in Table 2.
(Fusion strength: g / 10mm width)
A strip-like tape having a sample width of 10 mm was prepared from the nonwoven fabric, and using a Tensilon tester, the gripping interval was 50 m / m, and the tensile speed was 50 mm / min. Measured with
(Texture etc.)
The nonwoven fabric was evaluated by touch.
A: It has a soft and soft feel and is soft and voluminous.
○: A feeling of touch is rich.
Δ: Slightly sticky.
X: The yarn is loose, sticky, or stiff and hard.

[Comparative Examples 1-3]
Moreover, instead of the ethylene copolymer of an Example, the high density polyethylene (HD-1) and linear low density polyethylene (LL-1, LL-2) by a commercially available Ziegler type catalyst are used as a sheath material. Similarly, the core-sheath composite fiber and the nonwoven fabric were obtained and evaluated in the same manner.

  As described above, since the conjugate fiber of the present invention is excellent in flexibility and non-sticky, the nonwoven fabric obtained from such a conjugate fiber is much softer than conventional ones, and sanitary goods such as disposable diapers. Suitable for nonwoven fabrics used in

It is a graph which shows the elution temperature-elution amount curve of the (A) ethylene (co) polymer which concerns on this invention. It is a graph which shows the elution temperature-elution amount curve of the (A1) ethylene (co) polymer which concerns on this invention. It is a graph which shows the elution temperature-elution amount curve of the ethylene copolymer by a metallocene catalyst. It is a graph which shows the elution temperature-elution amount curve of the (A2) ethylene (co) polymer which concerns on this invention.

Claims (10)

A resin material containing (A) 100 to 20% by mass of an ethylene (co) polymer that satisfies the following requirements (a) to (d) and (B) 0 to 80% by mass of another polyolefin resin, and the resin material It consists of at least two components of (C) thermoplastic resin having a higher melting point,
A composite fiber having a fineness of 0.2 to 30 denier.
(A) a density of 0.86 to 0.97 g / cm ³ ,
(B) a melt flow rate of 2 to 200 g / 10 minutes,
(C) molecular weight distribution (Mw / Mn) is 1.5 to 4.5,
(D) Difference between temperature T _{25 at} which 25% of the elution is obtained from the integral elution curve of the elution temperature-elution amount curve by continuous temperature rising elution fractionation method (TREF) and temperature T _{75 at} which 75% of the elution is eluted T ₇₅ −T ₂₅ and density d satisfy the relationship of the following (Formula 1) (Formula 1) T ₇₅ −T ₂₅ ≦ −670 × d + 644 The composite fiber according to claim 1, wherein the (A) ethylene (co) polymer further satisfies the following requirement (e).
(E) The difference between the temperature T _{25 at} which 25% of the total elution is obtained from the integral elution curve of the elution temperature-elution amount curve by the continuous temperature rising elution fractionation method (TREF) and the temperature T _{75 at} which 75% of the total is eluted. T ₇₅ -T ₂₅ and density d satisfy the following relationship (Formula 2) (Formula 2) When d <0.950 g / cm ³
T ₇₅ −T ₂₅ ≧ −300 × d + 285
When d ≧ 0.950 g / cm ³
T ₇₅ -T ₂₅ ≧ 0 3. The (A) ethylene (co) polymer is an (A1) ethylene (co) polymer that further satisfies the following requirements (f) and (g). Composite fiber.
(F) The amount of orthodichlorobenzene (ODCB) soluble component X (mass%), density d, and melt flow rate (MFR) at 25 ° C. satisfy the relationship of the following (formula 3) and (formula 4) (formula 3) When d−0.008log MFR ≧ 0.93, X <2.0
(Formula 4) When d−0.008 log MFR <0.93 X <9.8 × 10 ³ × (0.9300−d + 0.008 log MFR) ² +2.0
(G) Multiple peaks of elution temperature-elution amount curve by continuous temperature rising elution fractionation method (TREF) exist. 3. The (A) ethylene (co) polymer is an (A2) ethylene (co) polymer that further satisfies the following requirements (h) and (i): 3. Composite fiber.
(H) One peak of elution temperature-elution amount curve by continuous temperature rising elution fractionation method (TREF) (i) One to two or more melting points, and the highest melting point T _ml and density d satisfies the relationship of the following (formula 5) (formula 5) T _ml ≧ 150 × d−19 The composite fiber according to claim 4, wherein the (A2) ethylene (co) polymer further satisfies the following requirement (j).
(J) Melt tension (MT) and melt flow rate (MFR) satisfy the following (formula 6) (formula 6) logMT ≦ −0.572 × logMFR + 0.3   The (A) ethylene (co) polymer is produced in the presence of a catalyst containing at least an organic cyclic compound having a conjugated double bond and a transition metal compound of Group 4 of the periodic table. The composite fiber according to any one of claims 1 to 5.   The composite fiber according to any one of claims 1 to 6, wherein a halogen concentration in the resin material is 10 ppm or less.   (A) 100 to 20% by mass of an ethylene (co) polymer and (B) a resin material containing 0 to 80% by mass of another polyolefin resin is a sheath, and (C) a thermoplastic resin having a higher melting point than the resin material. The composite fiber according to any one of claims 1 to 7, wherein is a core-sheath composite fiber having a core part. (A) a resin material satisfying the following requirements (a) to (d): 100 to 20% by mass of an ethylene (co) polymer and 0 to 80% by mass of another polyolefin resin, and a melting point higher than that of the resin material A composite fiber characterized in that at least two components of a high thermoplastic resin are spun from the same die, spun to a fineness of 0.5 to 80 denier, stretched as desired, and a fineness of 0.2 to 30 denier. Production method.
(A) a density of 0.86 to 0.97 g / cm ³ ,
(B) a melt flow rate of 2 to 200 g / 10 minutes,
(C) molecular weight distribution (Mw / Mn) is 1.5 to 4.5,
(D) Difference between temperature T _{25 at} which 25% of the elution is obtained from the integral elution curve of the elution temperature-elution amount curve by continuous temperature rising elution fractionation method (TREF) and temperature T _{75 at} which 75% of the elution is eluted T ₇₅ −T ₂₅ and density d satisfy the relationship of the following (Formula 1) (Formula 1) T ₇₅ −T ₂₅ ≦ −670 × d + 644 A nonwoven fabric comprising the conjugate fiber according to any one of claims 1 to 8.

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