U.S. patent application number 17/075258 was filed with the patent office on 2021-02-11 for spunbonded non-woven fabric and method for manufacturing same.
This patent application is currently assigned to IDEMITSU KOSAN CO., LTD.. The applicant listed for this patent is IDEMITSU KOSAN CO., LTD.. Invention is credited to Yohei KOORI, Yutaka MINAMI, Takumi SUGIUCHI, Tomoaki TAKEBE.
Application Number | 20210040298 17/075258 |
Document ID | / |
Family ID | 1000005168663 |
Filed Date | 2021-02-11 |
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United States Patent
Application |
20210040298 |
Kind Code |
A1 |
KOORI; Yohei ; et
al. |
February 11, 2021 |
SPUNBONDED NON-WOVEN FABRIC AND METHOD FOR MANUFACTURING SAME
Abstract
A nonwoven fabric formed of an olefin-based resin composition
(I) containing an olefin-based polymer (i) satisfying specific
requirements; a spunbond nonwoven fabric obtained by melt-extruding
and molding the olefin-based resin composition (I) at a resin
temperature of 220.degree. C. or lower, and a method for producing
it; a multilayer nonwoven fabric containing the spunbond nonwoven
fabric; a nonwoven fabric and a multilayer nonwoven fabric
including composite fibers containing an olefin-based resin
composition (II) containing an olefin-based polymer (ii) satisfying
specific requirements; and a fiber product using the spunbond
nonwoven fabric, the nonwoven fabric of composite fibers, or the
multilayer nonwoven fabric.
Inventors: |
KOORI; Yohei; (Ichihara-shi,
JP) ; TAKEBE; Tomoaki; (Ichihara-shi, JP) ;
MINAMI; Yutaka; (Ichihara-shi, JP) ; SUGIUCHI;
Takumi; (Ichihara-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IDEMITSU KOSAN CO., LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
IDEMITSU KOSAN CO., LTD.
Tokyo
JP
|
Family ID: |
1000005168663 |
Appl. No.: |
17/075258 |
Filed: |
October 20, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15322032 |
Dec 23, 2016 |
10844205 |
|
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PCT/JP2015/069347 |
Jul 3, 2015 |
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17075258 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 23/12 20130101;
C08L 2205/025 20130101; D04H 1/4291 20130101; D04H 3/007 20130101;
D04H 1/544 20130101; C08L 2203/12 20130101; D04H 3/14 20130101 |
International
Class: |
C08L 23/12 20060101
C08L023/12; D04H 3/007 20060101 D04H003/007; D04H 3/14 20060101
D04H003/14; D04H 1/544 20060101 D04H001/544; D04H 1/4291 20060101
D04H001/4291 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 3, 2014 |
JP |
2014-138009 |
Claims
1: A nonwoven fabric formed of composite fibers comprising the
following first component and second component: first component: an
olefin-based resin composition (I) containing an olefin-based
polymer (i) satisfying the following requirements (a) and (b): (a)
the melt flow rate (MFR) of the olefin-based polymer (i), as
measured under the condition of a temperature of 23.degree. C. and
a load of 21.18 N, is 1,000 g/10 min or more; and (b) the melting
endothermic amount .DELTA.H-D, as measured from the melting
endothermic curve drawn by keeping the olefin-based polymer (i) at
-10.degree. C. in a nitrogen atmosphere for 5 minutes and then
heating it at 10.degree. C./min in a nitrogen atmosphere using a
differential scanning calorimeter (DSC), is less than 80 J/g, and
second component: an olefin -based resin composition (II)
containing an olefin-based polymer (ii) satisfying the following
requirements (e) and (f): (e) the melt flow rate (MRF) of the
olefin-based polymer (ii), as measured under the condition of a
temperature of 230.degree. C. and a load of 21.18 N, is 1 g/10 mm
or more and 100 g/10 min or less; and (f) the melting point (Tm-D)
of the olefin-based polymer (b), as defined as a peak top of a peak
observed on the highest temperature side of the melting endothermic
curve drawn by keeping the composition at -10.degree. C. in a
nitrogen atmosphere for 5 minutes and then heating it at 10.degree.
C./min in a nitrogen atmosphere using a differential scanning
calorimeter (DSC), is higher than 120.degree. C.
2: The nonwoven fabric formed of composite fibers according to
claim 1, wherein the content of the olefin-based polymer (i) in the
olefin-based resin composition (I) is 1 to 50% by mass relative to
the total amount, 100% by mass of the olefin-based resin
composition (I).
3: The nonwoven fabric formed of composite fibers according to
claim 1, wherein the composite fibers are at least one kind
selected from the group consisting of a core-sheath type fiber, a
side-by-side type fiber and an eccentric core-sheath type
fiber.
4: The nonwoven fabric formed of composite fibers according to
claim 1, wherein the olefin-based polymer (i) is a propylene based
polymer.
5: A multilayer nonwoven fabric comprising two or more nonwoven
fabric layers, wherein at least one nonwoven fabric layer of the
multilayer nonwoven fabric is the nonwoven fabric formed of
composite fibers according to claim 1.
6: The multilayer nonwoven fabric according to claim 5, wherein at
least one nonwoven fabric layer of the multilayer nonwoven fabric
is a melt-blown nonwoven fabric.
7: A nonwoven fabric formed of composite fibers comprising the
following first component and second component: first component: an
olefin-based resin composition (I) containing an olefin-based
polymer (i) satisfying the following requirements (a) and (b): (a)
the melt flow rate (MFR) of the olefin-based polymer (i), as
measured under the condition of a temperature of 230.degree. C. and
a load of 21.18 N, is 1,000 g/1.0 min or more; and (b) the melting
endothermic amount .DELTA.H-D, as measured from the melting
endothermic curve drawn by keeping the olefin-based polymer (i) at
-10.degree. C. in a nitrogen atmosphere for 5 minutes and then
heating it at 10.degree. C./min in a nitrogen atmosphere using a
differential scanning calorimeter (DSC), is less than 80 J/g, and
second component: an olefin-based resin composition (II) containing
an olefin based polymer (ii) satisfying the following requirements
(e) and (f): (e) the melt flow rate (MFR) of the olefin-based
polymer (ii), as measured under the condition of a temperature of
230.degree. C. and a load of 21.18 N, is 1 g/10 min or more and 100
g/10 min or less; and (f) the melting point (Tm-D) of the
olefin-based polymer (ii), as defined as a peak top of a peak
observed on the highest temperature side of the melting endothermic
curve drawn by keeping the composition at -10.degree. C. in a
nitrogen atmosphere for 5 minutes and then heating it at 10.degree.
C./min in a nitrogen atmosphere using a differential scanning
calorimeter (DSC), is higher than 120.degree. C., wherein at least
one of the first component and the second component comprises an
internal release agent.
8: The nonwoven fabric formed of composite fibers according to
claim 7, wherein a content of the internal release agent is 1.0 to
10,000 ppm by mass based on the composition of the first component
or the second component comprising the internal release agent.
9: A nonwoven fabric formed of composite fibers comprising the
following first component and second component: first component: an
olefin-based resin composition (I) containing an olefin-based
polymer (i) satisfying the following requirements (a) and (b): (a)
the melt flow rate (MFR) of the olefin-based polymer (i), as
measured under the condition of a temperature of 230.degree. C. and
a load of 21.18 N, is 1,000 g/10 min or more; and (b) the melting
endothermic amount .DELTA.H-D, as measured from the melting
endothermic curve drawn by keeping the olefin-based polymer (i) at
-10.degree. C. in a nitrogen atmosphere for minutes and then.
heating it at 10.degree. C./min in a nitrogen atmosphere using a
differential scanning calorimeter (DSC), is less than 80 J/g, and
second component: an olefin-based resin composition (II) containing
an olefin-based polymer (ii) satisfying the following requirements
(e) and (f): (e) the melt flow rate (MFR) of the olefin-based
polymer (ii), as measured under the condition of a temperature of
230.degree. C. and a load of 21.18 N, is 1 g/10 min or more and 100
g/10 min or less; and (f) the melting point (Tm-D) of the olefin
based polymer (ii), as defined as a peak top of a peak observed on
the highest temperature side of the melting endothermic curve drawn
by keeping the composition at -10.degree. C. in a nitrogen
atmosphere for 5 minutes and then heating it at 10.degree. C./min
in a nitrogen atmosphere using a differential scanning calorimeter
(DSC), is higher than 120.degree. C., wherein at least one of the
first component and the second component comprises erucamide.
10: The nonwoven fabric formed of composite fibers according to
claim 9, wherein a content of the erucamide is 10 to 10,000 ppm by
mass based on the composition of the first component or the second
component comprising the erucamide.
11: A multilayer nonwoven fabric comprising two or more nonwoven
fabric layers, wherein at least one nonwoven fabric layer of the
multilayer nonwoven fabric is the nonwoven fabric formed of
composite fibers according to claim 7.
12: The multilayer nonwoven fabric according to claim 11, wherein
at least one nonwoven fabric layer of the multilayer nonwoven
fabric is a melt-blown nonwoven fabric.
Description
[0001] This application is a divisional of U.S. application Ser.
No. 15/322,032, allowed, filed as a U.S. National Stage on Dec. 23,
20016 of PCT/JP2015/069347 filed Jul. 3, 2015 and claims the
benefit of JP 2014-138009 filed Jul. 3, 2014.
TECHNICAL FIELD
[0002] The present invention relates to a spunbond nonwoven fabric
and a muitilayer nonwoven fabric containing the nonwoven fabric, a
method for producing them, a fiber product using the nonwoven
fabric, a nonwoven fabric formed of composite fibers and a
multilayer nonwoven fabric containing the nonwoven fabric fabric
formed of composite fibers, and a fiber product using the nonwoven
fabric of composite fibers.
BACKGROUND ART
[0003] In recent years, polypropylene-based fibers and
polypropylene nonwoven fabrics have been used in a variety of
applications, including disposable diapers, sanitary products,
hygienic products, clothing materials, bandages, and packing
materials. Thus, in use thereof, in many cases, the fibers and the
fabrics are brought into direct contact with bodies, and
performance requirements relating to good wearability and smooth
feel have become much increasing these days. Accordingly, regarding
nonwoven fabrics, technical developments relating to improvement of
feel for good wearability and reduction in basis weight for
achieving lightweight products have been desired. For such
performance improvements, optimization of the structure and the
composition of fibers constituting nonwoven fabrics, spinning
technique improvement, and flexibility improvement and strength
enhancement of nonwoven fabrics are desired.
[0004] PTL 1 discloses a spunbond nonwoven fabric using a resin
composition containing a low-crystalline polypropylene and a
high-crystalline polypropylene, saying that it is possible to
provide a polypropylene-based spunbond nonwoven fabric with good
smooth feel or a polypropylene-based spunbond nonwoven fabric with
high flexibility, which have an extremely small diameter and are
free from thread breakage.
CITATION LIST
Patent Literature
[0005] PTL 1: WO2011/030893
SUMMARY OF INVENTION
Technical Problem
[0006] For satisfying the requirements for spunbond non woven
fabrics for use for sanitary materials including disposable
diapers, stable molten resin extrudability and spinnability are
required from the viewpoint of moldability. Further, for such
spunbond nonwoven fabrics, further improvement of uniformity of
formation (texture, uniformity) is desired.
[0007] For stably extruding a molten resin, it is necessary to
suitably control the resin pressure in a die, and in particular, it
is necessary to set the resin temperature so that the pressure
could not be too high. In addition, for realizing stable spinning,
it is necessary to control the oriented crystallization of Fibers
and the spinning tension to be given to fibers on the spinning
line.
[0008] For this, it is desirable to low the viscosity of a resin
composition in a molten state, for example, by setting a high resin
temperature in molding, or increasing the melt flow rate (MFR) of
the resin composition to be used.
[0009] On the other hand, for uniformizing the formation of
nonwoven fabrics, it is necessary to promote the oriented
crystallization of the fibers constituting nonwoven fabrics to
increase the stiffness thereof, and therefore it is desirable to
set a low resin temperature in molding or to increase the melt
viscosity of the resin composition to be used.
[0010] Accordingly, it has been difficult to satisfy both stable
extrudability and spinnability of a molten resin and uniformization
of the formation of a nonwoven fabric.
[0011] The present invention has been made in consideration of the
above-mentioned situation and objects thereof are to provide a
spunbond nonwoven fabric excellent in formation uniformity, to
provide a production method of uniformly controlling the formation
of a spunbond nonwoven fabric while maintaining stable melt
extrudability and spinnability in molding a spunbond nonwoven
fabric, and to provide a fiber product using the spunbond nonwoven
fabric.
Solution to Problem
[0012] As a result of assiduous studies, the present inventors have
found that when a specific olefin-based resin composition
containing an olefin-based polymer satisfying specific requirements
is molded through melt extrusion, the extrudability and the
spinnability of the molten resin are stabilized, and have completed
a first aspect of the present invention.
[0013] Also, the present inventors have found that, in the first
aspect of the invention, when the olefin-based resin composition is
melt-extruded at a specific resin composition, uniformization of
the formation of the spunbond nonwoven fabric can be attained, and
have found a second aspect of the invention.
[0014] Also, the present inventors have found that the spinnability
of a nonwoven fabric containing composite fibers containing two
kinds of olefin-based resin compositions satisfying specific
requirements is also stabilized, the realizing uniformity of the
formation of the nonwoven fabric, and more uniformity of the
formation of a multilayer nonwoven fabric containing the nonwoven
fabric including composite fibers, and have completed a third
aspect of the present invention.
[0015] The present invention have been made on the basis of these
findings.
[0016] Specifically, the present invention provides of the
following inventions:
[1] A spunbond nonwoven fabric formed of an olefin-based resin
composition (I) containing an olefin-based polymer (i) satisfying
the following requirements (a) and (b):
[0017] (a) the melt flow rate (MFR) of the olefin-based polymer
(i), as measured under the condition of a temperature of
230.degree. C. and a load of 21.18 N, is 1,000 g/10 min or more;
and
[0018] (b) the melting endothermic amount .DELTA.H-D, as measured
from the melting endothermic curve drawn by keeping the
olefin-based polymer (i) at -10.degree. C. in a nitrogen atmosphere
for 5 minutes and then heating it at 10.degree. C./min in a
nitrogen atmosphere using a differential scanning calorimeter
(DSC), is less than 80 J/g.
[2] A spunbond nonwoven fabric obtained by melt-extruding an
olefin-based resin composition (I) containing an olefin-based
polymer (i) satisfying the following requirements (a) and (b), at a
resin temperature of 220.degree. C. or lower and mold the resultant
into a spunbond nonwoven fabric:
[0019] (a) the melt flow rate (MFR) of the olefin-based polymer
(i), as measured under the condition of a temperature of
230.degree. C. and a load of 21.18 N, is 1,000 g/10 min or more;
and
[0020] (b) the melting endothermic amount .DELTA.H-D, as measured
from the melting endothermic curve drawn by keeping the
olefin-based polymer (i) at -10.degree. C. in a nitrogen atmosphere
for 5 minutes and then heating it at 10.degree.0 C./min in a
nitrogen atmosphere using a differential scanning calorimeter
(DSC), is less than 80 J/g.
[3] The spunbond nonwoven fabric according to the above [1] or [2],
wherein satisfies the following requirement (1):
[0021] (1) the melt flow rate (MFR) of the olefin-based resin
composition (I), as measured under the condition of a temperature
of 230.degree. C. and a load of 21.18 N, is 40 g/10 min or
more.
[4] The spunbond non woven fabric according to any of the above [1]
to [3], wherein the olefin-based resin composition (I) further
satisfies the following requirement (2):
[0022] (2) the melting endothermic amount .DELTA.H-D, as measured
from the melting endothermic curve drawn by keeping the
olefin-based resin composition (I) at -10.degree. C. in a nitrogen
atmosphere for 5 minutes and then heating it at 10.degree. C./min
in a nitrogen atmosphere using a differential scanning calorimeter
(DSC), is less than 90 J/g.
[5] The spunbond nonwoven fabric according to any of the above [1]
to [4], wherein the content of the olefin-based polymer (i) in the
olefin resin composition (I) is 1 to 50% by mass relative to the
total amount, 100% by mass of the olefin resin composition (I). [6]
The spunbond nonwoven fabric according to any of the above [1] to
[5], wherein the olefin, polymer (i) is a propylene polymer (ip)
and satisfies the following requirements (c) and (d):
[0023] (c) the mesopentad fraction [mmmm] thereof is 20 to 60 mol
%; and
[0024] (d) [rrrr]/(1-[mmmm]).ltoreq.0.1.
[7] The spunbond nonwoven fabric according to any of the above [1]
to [6], wherein the olefin-lased resin composition (I) is a
propylene-based resin composition (IP). [8] A multilayer nonwoven
fabric formed by layering two or more nonwoven fabric layers,
wherein at least one nonwoven fabric layer constituting the
muitilayer nonwoven fabric is the spunbond nonwoven fabric of any
of the above [1] to [7]. [9] A method for producing a spunbond
nonwoven fabric, including a step of melt-extruding an olefin resin
composition (I) containing an olefin-based polymer (i) satisfying
the following requirements (a) and (b) at a resin temperature of
220.degree. C. or lower:
[0025] (a) the melt flow rate (MFR) of the olefin-based polymer
(i), as measured under the condition of a temperature of
230.degree. C. and a load of 21.18 N, is 1,000 g/10 min or more;
and
[0026] (b) the melting endothermic amount .DELTA.H-D, as measured
from the melting endothermic curve drawn by keeping the olefin
polymer (i) at -10.degree. C. in a nitrogen atmosphere for 5
minutes and then heating it at 10.degree. C./min in a nitrogen
atmosphere using a differential scanning calorimeter (DSC), is less
than 80 J/g.
[10] The method for producing a spunbond nonwoven fabric according
to the above [9], wherein the olefin-based resin composition (I)
satisfies the following requirement (1);
[0027] (1) the melt flow rate (MFR) of the olefin-based resin
composition (I), as measured under the condition of a temperature
of 230.degree. C. and a load of 21.15 N, 40 g/10 min or more.
[11] A nonwoven fabric formed of composite fibers containing the
following first component and second component:
[0028] first component: an olefin-based resin composition (I)
containing an olefin-based polymer (i) satisfying the following
requirements (a) and (b):
[0029] (a) the melt flow rate (MFR) of the olefin-based polymer
(i), as measured under the condition of a temperature of
230.degree. C. and a load of 21.18 N, is 1,000 g/10 min or more;
and
[0030] (b) the melting endothermic amount .DELTA.H-D, as measured
from the melting endothermic curve drawn by keeping the
olefin-based polymer (i) at -10.degree. C. in a nitrogen atmosphere
for 5 minutes and then heating it at 10.degree. C./min in a
nitrogen atmosphere using a differential scanning calorimeter
(DSC), is less than 80 J/g, and
[0031] second component: an olefin-based resin composition (II)
containing an olefin-based polymer (ii) satisfying the following
requirements (e) and (f):
[0032] (e) the melt flow rate (MFR) of the olefin-based polymer
(ii), as measured under the condition of a temperature of
230.degree. C. and a load of 21.18 N, is 1 g/10 min or more and 100
g/10 min or less; and
[0033] (f) the melting point (Tm-D) of the olefin-based polymer
(ii), as defined as a peak top of a peak observed on the highest
temperature side of the melting endothermic curve drawn by keeping
the composition at -10.degree. C. in a nitrogen atmosphere for 5
minutes and then heating it at 10.degree. C./min in a nitrogen
atmosphere using a differential scanning calorimeter (DSC), is
higher than 120.degree. C.
[12] The nonwoven fabric formed of composite fibers according to
the above [11], wherein the content of the olefin-based polymer (i)
in the olefin-based resin composition (I) is 1 to 50% by mass
relative to the total amount, 100% by mass of the olefin-based
resin composition (I). [13] The nonwoven fabric formed of composite
fibers according to the above [11] or [12], wherein the composite
fibers are at least one kind selected from a core-sheath type
fiber, a side-by-side type fiber and an eccentric core-sheath type
fiber. [14] A multilayer nonwoven fabric formed by layering two or
more nonwoven fabric layers, wherein at least one nonwoven fabric
layer constituting the multilayer nonwoven fabric is the nonwoven
fabric formed of composite fibers according to any of the above
[11] to [13]. [15] The multilayer nonwoven fabric according to the
above [14], wherein at least one nonwoven fabric layer constituting
the multilayer nonwoven fabric is a melt-blown nonwoven fabric.
[16] A fiber product using the spunbond nonwoven fabric of any of
the above [1] to [7], the nonwoven fabric formed of composite
fibers of any of the above [11] to [13], or the multilayer non
woven fabric of any of the above [8], [14] or [15].
Advantageous Effects of Invention
[0034] According to the present invention, there can be provided a
production method capable of uniformly controlling the formation of
a spunbond nonwoven fabric while maintaining stable melt
extrudability and spinnability in production of a spunbond nonwoven
fabric, as well as a spunbond nonwoven fabric excellent in
formation uniformity and a multilayer nonwoven fabric containing
the spunbond nonwoven fabric. In addition, the spunbond nonwoven
fabric is excellent in formation uniformity and has a good feel,
and therefore, for example, there can be provided fiber products
such as disposable diapers, sanitary products, hygiene products and
the like using the spunbond nonwoven fabric and the multilayer non
woven fabric.
DESCRIPTION OF EMBODIMENTS
First Aspect and Second Aspect of Invention
Spunbound Nonwoven Fabric
[0035] The spunbond nonwoven fabric of the first aspect of the
present invention is formed of an olefin-based resin composition
(I) containing an olefin-based polymer (i) satisfying the following
requirements (a) and (b):
[0036] (a) the melt flow rate (hereinafter this may be simply
referred to as "MFR") thereof, as measured under the condition of a
temperature of 230.degree. C. and a load of 21.18 N, is 1,000 g/10
min or more; and [0037] (b) the melting endothermic amount
.DELTA.H-D, as measured from the melting endothermic curve drawn by
keeping the composition at -10.degree. C. in a nitrogen atmosphere
for 5 minutes and then heating it at 10.degree. C./min in a
nitrogen atmosphere using a differential scanning calorimeter
(DSC), is less than 80 J/g.
[0038] The spunbond nonwoven fabric of the second aspect of the
present invention is obtained by melt-extruding and molding an
olefin-based resin composition (I) containing an olefin-based
polymer (i) satisfying the following requirements (a) and (b), at a
resin temperature of 220.degree. C. or lower:
[0039] (a) the melt flow rate (MFR) thereof, as measured under the
condition of a temperature of 230.degree. C. and a load of 21.18 N,
is 1,000 g/10 min or more; and
[0040] (b) the melting endothermic amount .DELTA.H-D, as measured
from the melting endothermic curve drawn by keeping the composition
at -10.degree. C. in a nitrogen atmosphere for 5 minutes and then
heating it at 10.degree. C./min n a nitrogen atmosphere using a
differential scanning calorimeter (DSC), is less than 80 J/g.
[0041] When the resin temperature of the olefin-based resin
composition (I) in melt extrusion is lower than 220.degree. C., a
crystallization on the spinning line becomes fast, and therefore
the stiffness of the fibers increases and a spunbond nonwoven
fabric having a high formation uniformity is easy to obtain.
[0042] From such a viewpoint, the resin temperature of the
olefin-based resin composition (I) in melt extrusion is preferably
215.degree. C. or lower, more preferably 210.degree. C. or lower.
The lower limit of the resin temperature is not specifically
defined, but is, in general, not lower than the inciting point of
the olefin based resin composition (I), preferably 180.degree. C.
or higher, more preferably 190.degree. C. or higher.
[0043] In this description, "resin temperature" means the
temperature at the resin extruding port of the extruder used.
[0044] The constituent components and the production methods for
the spunbond nonwoven fabric of the first aspect of the present
invention and the spunbond nonwoven fabric of the second aspect of
the present invention are described sequentially. The requirements
(a) and (b) similarly apply to all the spun bond nonwoven fabric of
the first aspect of the present invention and the spunbond nonwoven
fabric of the second aspect of the present invention and the
nonwoven fabric formed of composite fibers of the third aspect of
the present invention to be mentioned hereinunder, and the
preferred conditions thereof also apply unless otherwise
specifically indicated. The olefin-based polymer (i), the
olefin-based resin composition (I) and the constituent components
to be mentioned below are components that are to be similarly used
for the spunbond nonwoven fabric of the first aspect of the present
invention and the spunbond nonwoven fabric of the second aspect of
the present invention and for the nonwoven fabric formed of
composite fibers of the third aspect of the present invention to be
mentioned hereinunder, and the preferred embodiments thereof are
also the same unless otherwise specifically indicated.
[0045] In this description, the mere expression "the present
invention" indicates all the first aspect of the invention, the
second aspect of the invention and the third aspect of the
invention.
Olefin-Based Polymer (i)
[0046] The olefin-based polymer (i) for use in the present
invention satisfies the following requirements (a) and (b). The
following requirements (a) and (b) may be controlled by catalyst
selection and reaction condition in producing the olefin-based
polymer (i). The same may apply to the requirements (c) and (d).
Hereinunder in this description, the mere expression of
olefin-based polymer (i) indicates the olefin, polymer satisfying
the following requirements (a) and (b) for use in the present
invention.
[0047] (a) The melt flow rate (MFR) of the polymer, as measured
under the condition of a temperature of 230.degree. C. and a load
of 21.18 N, is 1,000 g/10 min or more.
[0048] hen MFR of the olefin-based polymer (i), as measured under
the condition of a temperature of 230.degree. C. and a load of
21.18 N is less than 1,000 g/10 min, the spinnability of the
olefin-based resin composition in melt extrusion is pour and it
becomes difficult to continuously obtain a spunbond nonwoven fabric
having high formation uniformity. In particular, in the case where
the resin temperature of the olefin resin composition (I) in melt
extrusion is 220.degree. C. or lower, the die pressure in melt
extrusion becomes unstable and stable spinning could not be carried
out, and therefore, it becomes more difficult to continuously
obtain a spunbond nonwoven fabric having high formation uniformity.
However, when the olefin-based polymer satisfies the requirement
(a), it becomes possible to continuously obtain a spunbond nonwoven
fabric having high formation uniformity.
[0049] From this viewpoint, MFR of the olefin-based polymer (i) is
preferably 1,500 g/10 min or more, more preferably 1,800 g/10 min
or more, even more preferably 2,000 g/10 min or more.
[0050] The melt flow rate (MFR) is a value measured according to
the measurement method described in the section of Examples to be
given hereinunder.
[0051] (b) The melting endothermic amount .DELTA.H-D of the
polymer, as measured from the melting endothermic curve drawn by
keeping the composition at -10.degree. C. in a nitrogen atmosphere
for 5 minutes and then heating it at 10.degree. C./min in a
nitrogen atmosphere using a differential scanning calorimeter
(DSC), is less than 80 J/g.
[0052] When the melting endothermic amount .DELTA.H-D of the
olefin-based polymer (i) is 80 J/g or more, it is impossible to
prevent thread breakage of fibers in melt extrusion of the olefin
resin-based composition (I), and the spinnability is unstable, and
therefore it becomes difficult to obtain a spunbond nonwoven fabric
having high formation uniformity. From this viewpoint, the melting
endothermic amount .DELTA.H-D is preferably 70 J/g or less, more
preferably 60 J/g or less.
[0053] The olefin-based polymer (i) is preferably a propylene-based
polymer, and more preferably a propylene-based polymer (ip)
satisfying the following requirements (c) and (d). Hereinunder in
this description, the mere expression of propylene-based polymer
(ip) indicates the propylene resin satisfying the above
requirements (a) and (b), and the following requirements (c) and
(d) for use in the present invention.
[0054] The propylene-based resin not satisfying the requirements
includes, though not specifically limited, any other polypropylene
and the like to be mentioned hereinunder.
[0055] (c) The mesopentad fraction [mmmm] of the polymer is 20 to
60 mol %;
[0056] When the mesopentad fraction [mmmm] is 20 mol % or more, the
melt extrudability of the olefin-based resin composition (I) and
the spinnability in using the resin composition (I) can be
stabilized therefore realizing conformation uniformity. When the
mesopentad fraction [mmmm] is 60 mol % or less, the nonwoven fabric
formed of the resin composition can be flexible and can realize
formation uniformity. From these viewpoints, the mesopentad
fraction [mmmm] is preferably 30 mol % or more and 60 mol % or
less, more preferably 40 mol % or more and 60 mol % or less, even
more preferably 40 mol % or more and 55 mol % or less.
[0057] (d) [rrrr]/(1-[mmmm]).ltoreq.0.1
[0058] The value [rrrr]/(1-[mmmm]) is an indicator showing the
uniformity of the regularity distribution of the propylene-based
polymer. When [rrrr]/(1-[mmmm]) of the propylene-based polymer is
0.1 or less, the regularity distribution becomes narrow, and a
mixture of a high-stereoregularity polypropylene and an atactic
polypropylene, as in the case of a conventional polypropylene
produced in the presence of an existing catalyst system to cause
stickiness, can be prevented from being formed. From this
viewpoint, [rrrr]/(1-[mmmm]) is preferably 0.05 or less, more
preferably 0.04 or less.
[0059] The stereoregularity of the above (c) and (d) is determined
by NMR.
[0060] In the present invention, the mesopentad fraction [mmmm] and
the racemic pentad fraction [rrrr] are measured in conformity with
the method proposed by A. Zambelli, et al., "Macromolecules, 6, 925
(1973)" and are a meso fraction and a racemic fraction,
respectively, in the pentad units of the polypropylene molecular
chain that are measured based on a signal of the methyl group in
the .sup.13C-NMR spectrum. As the mesopentad fraction [mmmm]
increases, the stereoregularity increases.
[0061] The measurement of the .sup.13C-NMR spectrum in this
description was performed by a method described in the section of
Examples.
[0062] The propylene-based polymer (ip) may be either a propylene
homopolymer or a copolymer. In the case of a copolymer, a
copolymerization ratio of the propylene unit is 50 mol % or more,
preferably 60 mol % or more, and more preferably 70 mol % or more.
Examples of the copolymerizable monomer include .alpha.-olefins
having 2 or 4 to 20 carbon atoms, such as ethylene, 1-butene,
1-pentene, 1-hexene, 1-octene, 1-decene, etc., acrylic esters, such
as methyl acrylate, etc., vinyl acetate, and the like. From the
viewpoint of moldability, a propylene homopolymer is preferred. One
alone or two or more kinds of these polymers may be used either
singly or as combined.
[0063] The above-described propylene-based polymer (ip) can be
produced using a metallocene-based catalyst as described in, for
example, WO 2003/087172. In particular, a metallocene-based
catalyst using a transition metal compound in which a ligand forms
a crosslinked structure via a crosslinking group is preferred.
Above all, a metallocene-based catalyst obtained by combining a
transition metal compound in which a crosslinked structure is
formed via two crosslinking groups with a cocatalyst is
preferred.
[0064] Specifically, examples thereof include a polymerization
catalyst containing (A) a transition metal compound represented by
the following general formula (I) and (B) a cocatalyst component
selected from (B-1) a compound capable of reacting with the
transition metal compound that is the component (A) or a derivative
thereof to form an ionic complex and (B-2) an aluminoxane.
##STR00001##
[0065] Wherein, In the formula, M represents a metal element
belonging to any one of the Groups 3 to 10 or the lanthanoid series
in the periodic table; each of E.sup.1 and E.sup.2 represents a
ligand selected from a substituted cyclopentadienyl group, an
indenyl group, a substituted indenyl group, a
heterocyclopentadienyl group, a substituted heterocyclopentadienyl
group, an amide group, a phosphide group, a hydrocarbon group, and
a silicon-containing group, and forms a crosslinked structure via
A.sup.1 and A.sup.2, and may be the same as or different from each
other; X represents a .sigma.-bonding ligand, and when a plurality
of Xs are present, the plurality of Xs may be the same as or
different from each other, and each X may crosslink with any other
X, E.sup.1, E.sup.2, or Y; Y represents a Lewis base, and when a
plurality of Ys are present, the plurality of Ys may be the same as
or different from each other, and each Y may crosslink with any
other Y, E.sup.1, E.sup.2, or X; each of A.sup.1 and A.sup.2
represents a divalent crosslinking group that bonds two ligands and
represents 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.sub.2--, --Se--,
--NR.sup.1--, --PR.sup.1--, --P(O)R.sup.1--, --BR.sup.1--, or
--AlR.sup.1--, wherein R.sup.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,
and may be the same as or different from each other; q represents
an integer of 1 to 5 and corresponds to [(valence of M)-2]; and r
represents an integer of 0 to 3.
[0066] The transition metal compound that is the above-described
component (A) is preferably a transition metal compound in which
the ligand is of a (1,2')(2,1') double crosslinking type, and
examples thereof include
(1,2'-dimethylsilylene)(2,1'-dimethylsilylene)-bis(3-trimethylsilylmethyl-
indenyl)zirconium dichloride.
[0067] As specific examples, of the compound that is the
above-described component (B-1) of the component (B), there may be
exemplified triethylammonium tetraphenylborate, tri-n-butylammonium
tetraphenylborate, trimethylammonium tetraphenylborate,
tetraethylammonium tetraphenylborate, methyl(tri-n-butyl)ammonium
tetraphenylborate, benzyl(tri-n-butyl)ammonium tetraphenylborate,
dimethyldiphenylammonium tetraphenylborate,
triphenyl(methyl)ammonium tetraphenylborate, trimethylanilinium
tetraphenylborate, methylpyridinium tetraphenylborate,
benzylpyridinium tetraphenylborate, methyl(2-cyanopyridinium)
tetraphenylborate, triethylammomum
tetrakis(pentafluorophenyl)borate, tri-n-butylammonium
tetrakis(pentafluorophenyl)borate, triphenylammonium
tetrakis(pentafluorophenyl)borate, tetra-n-butylammonium
tetrakis(pentafluorophenyl)borate, tetraethylammonium
tetrakis(pentafluorophenyl)borate, benzyl(tri-n-butyl)ammonium
tetrakis(pentafluorophenyl)borate, methyldiphenylammonium
tetrakis(pentafluorophenyl)borate, triphenyl(methyl)ammonium
tetrakis(pentafluorophenyl)borate, methylanilinium
tetrakis(pentafluorophenyl)borate, dimethylanilinium
tetrakis(pentafluorophenyl)borate, trimethylanilinium
tetrakis(pentafluorophenyl)borate, methylpyridinium
tetrakis(pentafluorophenyl)borate, benzylpyridinium
tetrakis(pentafluorophenyl)borate, methyl(2-cyanopyridinium)
tetrakis(pentafluorophenyl)borate, benzyl(2-cyanopyridinium)
tetrakis(pentafluorophenyl)borate, methyl(4-cyanopyridinium)
tetrakis(pentafluorophenyl)borate, triphenylphosphonium
tetrakis(pentafluorophenyl)borate, dimethylanilinium
tetrakis[bis(3,5-ditrifluoromethyl)phenyl]borate, ferrocenium
tetraphenylborate, silver tetraphenylborate, trityl
tetraphenylborate, tetraphenylporphyrinmanganese tetraphenylborate,
ferrocenium tetrakis(pentafluorophenyl)borate,
(1,1'-dimethylferrocenium) tetrakis(pentafluorophenyl)borate,
decamethylferrocenium tetrakis(pentafluorophenyl)borate, silver
tetrakis(pentafluorophenyl)borate, trityl
tetrakis(pentafluorophenyl)borate, lithium
tetrakis(pentafluorophenyl)borate, sodium
tetrakis(pentafluorophenyl)borate, tetraphenylporphyrinmanganese
tetrakis(pentafluorophenyl)borate, silver tetrafluoroborate, silver
hexafluorophosphate, silver hexafluoroarsenate, silver perchlorate,
silver trifluoroaceate, silver trifluoromethanesulfonate, and the
like.
[0068] One alone or two or more kinds of (B-1) may be used either
singly or as combined.
[0069] Examples of the aluminoxane that is the above-described
component (B-2) include known chain aluminoxanes and cyclic
aluminoxanes. One alone or two or more kinds of these aluminoxanes
may be used either singly or as combined. Also one or more of the
above component (B-1) and one or more of the above component (B-2)
may be combined.
[0070] As the metallocene-based catalyst, an organic aluminum
compound may be used as a component (C) as combined with the
component (A) and the component (B) for producing the
propylene-based polymer.
[0071] The organic aluminum compound for the component (C) includes
trimethylaluminum, triethylaluminum, triisopropylaluminum,
triisobutylaluminum, dimethylaluminum chloride, diethylaluminum
chloride, methylaluminum dichloride, ethylaluminum dichloride,
dimethylaluminum fluoride, diisobutylaluminum hydride,
diethylaluminum hydride, ethylaluminum sesquichloride, etc. One
alone or two or more kinds of these organic aluminum compounds may
be used either singly as combined. In polymerization of propylene,
at least one catalyst component can be held by a suitable
carrier.
[0072] The polymerization method is not specifically limited, and a
method of a slurry polymerization method, a vapor-phase
polymerization method, a hulk a method, a solution polymerization
method, suspension polymerization method or the like may be used. A
bulk polymerization method and a solution polymerization method are
especially preferred. The polymerization temperature is generally
-100 to 250.degree. C., and the ratio of the catalyst to be used
relative to the reactant is preferably such that reactant
monomer/component (A) (molar ratio) is 1 to 10.sup.8, more
preferably 100 to 10.sup.5. The polymerization time is generally 5
minutes to 10 hours, and the reaction pressure is generally
ordinary pressure to 20 MPa (gauge).
Other Polypropylene
[0073] The other polypropylene that may be used in the first aspect
and the second aspect of the present invention is one haying MFR,
as measured at a temperature of 280.degree. C. and under a load of
21.18 N, is 1 g/10 min or more and less than 1,000 g/10 min,
preferably 10 g/10 min or more and 700 g/10 min or less, more
preferably 15 g/10 min or more and 500 g/10 min or less, even more
preferably 18 g/10 min or more and 100 g/10 min or less.
[0074] The melt flow rate (MFR) is a value measured according to
the measurement method stipulated in JIS K7210, using an
extrusion-type plastometer defined in JIS K6760.
[0075] The other polypropylene that may be used in the first aspect
and the second aspect of the present invention is not particularly
limited so long as its melting point (Tm-D) defined as a peak top
of a peak observed on the highest temperature side of the melting
endothermic curve obtained by holding under a nitrogen atmosphere
at -10.degree. C. for 5 minutes and then increasing the temperature
at a rate of 10.degree. C./min under a nitrogen atmosphere by using
a differential scanning calorimeter (DSC) exceeds 120.degree. C.
High crystalline polypropylenes such as PP3155 (trade name,
manufactured by ExxonMobil Chemical), Y2005GP (trade name,
manufactured by Prime Polymer Co., Ltd.), Prime Polypro.TM. S119
(trade name, manufactured by Prime Polymer Co., Ltd), NOVATEC-SA03
(trade name, manufactured by Japan Polypropylene Corporation) and
the like may be used.
[0076] The other polypropylene may be either a propylene
homopolymer or a copolymer. In the case of a copolymer, the
copolymerization ratio of the propylene unit is 50 mol % or more,
preferably 60 mol % or more, more preferably 70 mol % or more,
still more preferably 90 mol % or more, and still even more
preferably 95 mol % or more. Examples of copolymerizable monomers
include .alpha.-olefins having 2 or 4 to 20 carbon atoms, such as
ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, etc.,
acrylic esters, such as methyl acrylate, etc., vinyl acetate, and
the like. From the viewpoint of moldability, a propylene
homopolymer is preferred. One alone or two or more kinds of such
polymers may be used either singly or as combined.
[0077] As the other polypropylene, one having a melting point
(Tm-D), defined as a peak top of a peak observed on the highest
temperature side of the melting endothermic curve obtained by
holding under a nitrogen atmosphere at -10.degree. C. for 5 minutes
and then increasing the temperature at a rate of 10.degree. C./min
under a nitrogen atmosphere by using a differential scanning
calorimeter (DSC), of higher than 120.degree. C. and 170.degree. C.
or lower is preferred, and one having the melting point of 125 to
167.degree. C. is more preferred.
Olefin-Based Resin Composition (I)
[0078] The olefin-based resin composition (I) for use in the
present invention contains the olefin-based polymer (i) satisfying
the above-mentioned requirements (a) and (b). Hereinunder in this
description, the mere expression of olefin-based resin composition
(I) indicates the olefin-based resin composition that contains the
olefin-based polymer (i) satisfying the requirements (a) and (b)
for use in the present invention.
[0079] The content of the olefin-based polymer (i) in the
olefin-based resin composition (I) is, relative to the total amount
100% by mass of the olefin-based resin composition (I), preferably
1 to 50% by mass, more preferably 3 to 40% by mass, even more
preferably 5 to 30% by mass.
[0080] Preferably, the olefin-based resin composition (I) satisfies
the following requirement (1), more preferably, additionally
satisfying the following requirement (2).
[0081] (1) The melt flow rate (MFR) of the composition, as measured
under the condition of a temperature of 230.degree. C. and a load
of 21.18 N, is 40 g/10 min or more.
[0082] Regarding the olefin-based resin composition (I) for use in
the present invention, preferably, MFR, as measured under the
condition of a temperature of 230.degree. C. and a load of 21.18 N,
is 40 g/10 min or more.
[0083] When MFR of the olefin-based resin composition (1) is 40
g/10 min or more, the die pressure could still be stable and the
spinnability could also be stable even though the composition is
extruded at a resin temperature of 220.degree. C. or lower in melt
extrusion, and therefore a spunbond nonwoven fabric having higher
formation uniformity could be obtained.
[0084] From this viewpoint, MFR of the olefin-based resin
composition (I) is more preferably 45 g/10 min or more, even more
preferably 48 g/10 min or more.
[0085] (2) The melting endothermic amount .DELTA.H-D of the
composition, as measured from the melting endothermic curve drawn
by keeping the composition at -10.degree. C. in a nitrogen
atmosphere for 5 minutes and then heating it at 10.degree. C./min
in a nitrogen atmosphere using a differential scanning calorimeter
(DSC), is less than 90 J/g.
[0086] When the melting endothermic amount .DELTA.H-D of the
olefin-based resin composition (I) is less than 90 J/g, the die
pressure could be stable and the spinnability could also he stable,
and therefore a spunbond nonwoven fabric having higher formation
uniformity could be obtained. From this viewpoint, the melting
endothermic amount .DELTA.H-D is more preferably 86 J/g or less,
even more preferably 81 J/g or less.
[0087] The melting endotherm .DELTA.H-D is calculated in a manner
in which when a line connecting a point on the low-temperature side
free from a change in the amount of heat with a point on the
high-temperature side free from a change in the amount of heat is
defined as a baseline, and an area surrounded by a line portion
including the peak of the melting endothermic curve obtained by the
DSC measurement and the baseline is determined.
[0088] The olefin-based resin composition (I) is preferably a
propylene-based resin composition (IP). In this description, the
propylene-based resin composition (IP) means an olefin-based resin
composition in which the proportion of the propylene-based polymer
(ip) and the other polypropylene in the olefin-based resin
composition (I) is 50% by mass or more.
[0089] The proportion of the propylene-based polymer (ip) and the
other polypropylene in the olefin-based resin composition (I) is
preferably 70% by mass or more, more preferably 80% by mass or
more, even more preferably 90% by mass or more, still even more
preferably 95% by mass or more.
[0090] Hereinunder in this description, the mere expression of
propylene-based resin composition (IP) indicates a propylene-based
resin composition that contains the olefin-based polymer (i)
satisfying the above-mentioned requirements (a) and (b) for use in
the present invention.
[0091] The olefin-based resin composition (I) may contain various
additives such as any other thermoplastic resin, release agent and
the like, within a range not detracting from the advantageous
effects of the first aspect and the second aspect of the present
invention.
[0092] The other thermoplastic resin includes other olefin polymers
than the above-mentioned olefin-based polymer (i), concretely
polypropylene, propylene-ethylene copolymer,
propylene-ethylene-diene copolymer, polyethylene,
ethylene/.alpha.-olefin copolymer, ethylene-vinyl acetate
copolymer, hydrogenated styrene elastomer, etc. Polyester,
polyamide, polylactic acid and the like are also included. One
alone or two or more kinds of these may be used either singly or as
combined.
[0093] The release agent is an additive for enhancing releasability
in order that the molded nonwoven fabric would not adhere to the
roll, the conveyor and the like of the molding machine. The release
agent that is contained in the resin composition is referred to as
an internal release agent, and the internal release agent is an
additive to be added to the resin material for enhancing the
releasability of the nonwoven fabric formed. An external release
agent is an additive that is directly applied to the roll or the
conveyor of a molding machine for enhancing the releasability of
the nonwoven fabric formed.
[0094] The internal release agent includes organic carboxylic acids
and metal salts thereof, aromatic sulfonic acids and metal salts
thereof, organic phosphoric arid compounds and metal salts thereof,
dibenzylidene sorbitol and derivatives thereof, rosin arid partial
metal salts, inorganic fine particles, imide acids, amide acids,
quinacridons, quinones, and mixtures thereof.
[0095] The metal in the metal salts of organic carboxylic acids
include Li, Ca, Ba, Zn, Mg, Al, Pb, etc. The carboxylic acid
includes fatty acids such as octylic acid, palmitic acid, lauric
acid, stearic acid, behenic acid, montanic acid, 12-hydroxystearic
acid, oleic acid, isostearic acid, ricinoleic acid, etc., and
aromatic carboxylic acids such as benzoic acid, p-t-butyl-benzoic
acid, etc. Specific examples of the salts include aluminum
benzoate, aluminum p-t-butylbenzoate, sodium adipate, sodium
thiophenecarboxylate, sodium pyrrolecarboxylate, etc.
[0096] Examples of dibenzylidene sorbitol and its derivatives
include dibenzylidene sorbitol,
1,3:2,4-bis(o-3,4-dimethylbenzylidene)sorbitol,
1,3:2,4-bis(o-2,4-dimethylbenzylidene)sorbitol,
1,3:2,4-bis(o-4-ethylbenzylidene)sorbitol,
1,3:2,4-bis(o-4-chlorobenzylidene)sorbitol, 1,3:2,4-dibenzylidene
sorbitol, etc. Examples of commercially available products thereof
include GEL ALL MD and GEL ALL MD-R, all of which are manufactured
by New Japan Chemical Co., Ltd., etc.
[0097] Examples of the rosin acid partial metal salt include
PINECRYSTAL KM1600, PINECRYSTAL KM1500, and PINECRYSTAL KM1300, all
of which are manufactured by Arakasva Chemical Industries, Ltd.,
etc.
[0098] Examples of the inorganic fine particles include talc, clay,
mica, asbestos, glass fiber, glass flake, glass bead, calcium
silicate, montmorillonite, bentonite, graphite, aluminum powder,
alumina, silica, diatomaceous earth, titanium oxide, magnesium
oxide, pumice powder, pumice balloon, aluminum hydroxide, magnesium
hydroxide, basic magnesium carbonate, dolomite, calcium sulfate,
potassium titanate, barium sulfate, calcium sulfite, molybdenum
sulfide, etc. Examples of commercially available products thereof
include SYLYSIA, manufactured by Fuji Silysia Chemical Ltd.,
MIZUKASIL, manufactured by Mizusawa Industrial Chemicals, Ltd.,
etc.
[0099] The amide compound includes erucamide, oleamide, stearamide,
behenamide, ethylenebisstearamide, ethylenebisoleamide,
stearylerucamide, oelylpalmitamide, adipic dianilide, suberic
dianilide, etc.
[0100] Examples of the organic phosphoric acid compound include
trimethyl phosphate, triethyl phosphate, tributyl phosphate,
2-ethylhexyl phosphate, butoxyethyl phosphate, triphenyl phosphate,
tricresyl phosphate, trixylenyl phosphate, cresyldiphenyl
phosphate, 2-ethylhexyldiphenyl phosphate, cresyldi-2,6-xylenyl
phosphate, resorcinoldiphenol phosphate, various aromatic condensed
phosphate esters, 2-chioroethyl phosphate, chloropropyl phosphate,
dichloropropyl phosphate, tribromoneopentyl phosphate,
halogen-containing condensed phosphoric acid, bis-2-ethylhexyl
phosphate, diisodecyl phosphate, 2-methacryloyloxyethyl acid
phosphate, diphenyl-2-methacryloyloxyethyl phosphate, methyl acid
phosphate, butyl acid phosphate, monoisodecyl phosphate,
2-butylhexyl acid phosphate, isodecyl acid phosphate, triphenyl
phosphate, dibutyl hydrogen phosphate, polyoxyethylene lauryl ether
phosphoric acid, polyoxyalkyl ether phosphoric acid,
polyoxyethylene alkyl phenyl ether phosphoric acid, polyoxyethylene
dialkyl phenyl ether phosphoric acid, etc.; and examples of the
metal salt of organic phosphoric acid compound include salts of Li,
Ca, Ba, Zn, Mg, Al, Pb or the like of the above-described organic
phosphoric acid compounds. Examples of commercially available
products thereof include ADEKA STAB NA-11 and ADEKA STAB NA-21, all
of which are manufactured by ADEKA Corporation, etc.
[0101] These internal release agents may be used solely or in
combination of two or more kinds thereof. In the present invention,
among these internal release agents, one selected from erucamide,
dibenzylidene sorbitol,
1,3:2,4-bis(o-3,4-dimethylbenzylidene)sorbitol,
1,3:2,4-bis(o-2,4-dimethylbenzylidene)sorbitol,
1,3:2,4-bis(o-4-ethylbenzylidene)sorbitol,
1,3:2,4-bis(o-4-chlorobenzylidene)sorbitol and
1,3:2,4-dibenzylidene sorbitol is preferred.
[0102] The content of the internal release agent in the olefin
resin composition (I) is preferably 10 to 10,000 ppm by mass, more
preferably 100 to 5,000 ppm by mass on the basis of the resin
composition excluding the additive. When the content of the
internal release agent is 10 ppm by mass or more, the function as
the release agent is revealed, whereas when it is 10,000 ppm by
mass or less, the balance between the function of the release agent
and the economic potential thereof is good.
[0103] As other various additives than the internal release agent,
any conventional known additive may be incorporated in the resin
composition. Examples of the other additives include a foaming
agent, a crystal nucleating agent, a weatherability stabilizer, a
UV absorber, a light stabilizer, a heat resistance stabilizer, an
antistatic agent, a flame retardant, a synthetic oil, a wax, an
electric property-improving agent, a slip inhibitor, an
anti-blocking agent, a viscosity-controlling agent, a coloring
inhibitor, a defogging agent, a lubricant, a pigment, a dye, a
plasticizer, a softening agent, an age resistor, a hydrochloric
acid-absorbing agent, a chlorine scavenger, an antioxidant, an
antirack agent, etc.
Uniformity of Formation
[0104] The spunbond nonwoven fabric of the first aspect and the
second aspect of the present invention is a spunbond nonwoven
fabric having a uniformity of formation of preferably 3.0 or less.
The uniformity of formation is a value to be calculated according
to the method described in the section of Examples give
hereinunder. When the uniformity of formation is 3.0 or less, the
spunbond nonwoven fabric may have excellent design performance and
excellent feeling, and can be favorably used for sanitary materials
including disposable diapers.
Multilayer Nonwoven Fabric
[0105] The multilayer nonwoven fabric of the first aspect and the
second aspect of the present invention is a multilayer nonwoven
fabric formed by layering two or more nonwoven fabric layers, and
at least one nonwoven fabric layer constituting the multilayer
nonwoven fabric may be the above-mentioned spunbond nonwoven fabric
of the present invention. The multilayer nonwoven fabric containing
one or more spunbond non woven fabrics of the present invention is
excellent in uniform hot workability (advantageous effect). The
nonwoven fabric for use in the other layer than the layer of the
spunbond nonwoven fabric of the first aspect and the second aspect
of the present invention may be, though not specifically limited, a
nonwoven fabric to be obtained according to a known production
method such as a spunbonding method, a melt-blowing method, a
spun-lacing method, a carding method or the like.
Method for Producing Spunbond Nonwoven Fabric
[0106] The method for producing the spunbond nonwoven fabric for
use in the first aspect of the present invention is, though not
specifically limited, a production method for a spunbond nonwoven
fabric that includes a step of melt-extruding the olefin-based
resin composition (I) containing the olefin-based polymer (i)
satisfying the following requirements (a) and (b).
[0107] (a) The melt flow rate (MRF) thereof, as measured under the
condition of a temperature of 230.degree. C. and a load of 21.18 N,
is 1,000 g/10 min or more.
[0108] (b) The melting endothermic amount .DELTA.H-D, as measured
from the melting endothermic curve drawn by keeping the composition
at -10.degree. C. in a nitrogen atmosphere for 5 minutes and then
heating it at 10.degree. C./min in a nitrogen atmosphere using a
differential scanning calorimeter (DSC), is less than 80 J/g.
[0109] The olefin-based polymer (i) satisfying the requirements (a)
and (b) is the same as the olefin-based polymer (i) for use in the
spunbond nonwoven fabric of the present invention described above,
and preferred examples thereof are also the same. In addition,
preferred ranges of the requirements (a) and (b) are also the
same.
[0110] The production method for the spunbond nonwoven fabric for
use in the second aspect of the present invention is a production
method for a spunbond nonwoven fabric that includes a step of
melt-extruding the olefin-based resin composition (I) containing
the olefin-based polymer (i) satisfying the following requirements
(a) and (b), at a resin temperature of 220.degree. C. or lower.
[0111] (a) The melt flow rate (MFR) thereof, as measured under the
condition of a temperature of 230.degree. C. and a load of 21.18 N,
is 1,000 g/10 min or more.
[0112] (b) The melting endothermic amount .DELTA.H-D, as measured
from the melting endothermic curve drawn by keeping the composition
at -10.degree. C. in a nitrogen atmosphere for 5 minutes and then
heating it at 10.degree. C./min in a nitrogen atmosphere using a
differential scanning calorimeter (DSC), is less than 80 J/g.
[0113] The olefin-based polymer (i) satisfying the requirements (a)
and (b) is the same as the olefin-based polymer (i) for use in the
spunbond nonwoven fabric of the present invention described above,
and preferred examples thereof are also the same. In addition,
preferred ranges of the requirements (a) and (b) are also the
same.
[0114] The production method for the spunbond nonwoven fabric for
use in the second aspect of the present invention includes a step
of melt-extruding the olefin-based resin composition (I) satisfying
the above-mentioned requirements at a resin temperature of
220.degree. C. or lower.
[0115] In the case where an olefin-based resin composition not
satisfying the above-mentioned requirements is melt-extruded at a
resin temperature of 220.degree. C. or lower, the die pressure is
unstable and the spinnability lowers. When the olefin resin
composition not containing the olefin-based polymer (i) satisfying
the requirements (a) and (b) is extruded at a resin temperature of
220.degree. C. or lower, thread breakage occurs and it becomes
difficult to obtain a spunbond nonwoven fabric having high
formation uniformity.
[0116] On the other hand, in the case where the olefin-based resin
composition (I) satisfying the above-mentioned requirement (i) is
used and the melt extrusion is carried out at a resin temperature
lower than 220.degree. C., oriented crystallization of the fibers
constituting the nonwoven fabric formed proceeds sufficiently and
the stiffness of the fibers is not too low, and therefore a
spunbond nonwoven fabric having higher formation uniformity can be
obtained.
[0117] From these viewpoints, the resin temperature of the
olefin-based resin composition in melt extrusion is preferably
215.degree. C. or lower, more preferably 210.degree. C. or lower.
The lower limit of the resin temperature is, also though not
specifically limited, generally not lower than the melting point of
the olefin-based resin composition (I), and is preferably
180.degree. C. or higher, more preferably 190.degree. C. or
higher.
[0118] The production method for the spunbond nonwoven fabric for
use in the second aspect of the present invention is preferably a
production method for a spunbond nonwoven fabric using the
olefin-based resin composition (I) satisfying the following
requirement (1).
[0119] (1) MFR of the resin composition, as measured under the
condition of a temperature of 230.degree. C. and a load of 21.18 N,
is 40 g/10 min or more.
[0120] The olefin-based resin composition (I) containing the
olefin-based polymer (i) that satisfies the above requirements (a)
and (b), and further satisfying the above (1) is the same as the
olefin-based resin composition (I) satisfying the requirement for
use in the spunbond nonwoven fabric of the present invention
mentioned above, and preferred examples thereof are also the same.
The preferred range of the requirement (1) is also the same as
above.
[0121] Since the olefin-based resin composition (I) satisfying the
requirement is used, the die pressure is not unstable and the
spinnability is improved more even when the melt extrusion is
carried out at a resin temperature of 220.degree. C. or lower.
Since the olefin-based resin composition (I) satisfying the above
requirement (1) contains the olefin-based polymer (i) satisfying
the above requirements (a) and (b), the melt extrusion is stable
even though the resin composition is extruded at a resin
temperature of 220.degree. C. or lower, and the spinnability is
stabilized with preventing thread breakage. Further, since the
resin composition is extruded at a resin temperature of 220.degree.
C. or lower, the crystallization on the spinning line is promoted,
and the stiffness of the fibers formed is high, and therefore a
spunbond nonwoven fabric having high formation uniformity can be
obtained.
[0122] In a spunbonding method, in general, a melt-kneaded
crystalline resin composition is spun, stretched and opened to give
continuous long fibers, and in the subsequent continuous process,
the continuous long fibers are deposited on a moving, and
collecting surface and entangled thereon to give a spunbond
nonwoven fabric. According to the method, a nonwoven fabric can be
produced continuously, and the fibers constituting the spunbond
nonwoven fabric are stretched continuous long fibers and therefore
have high strength.
[0123] As the spunbonding method, any conventional known method is
employable. For example, from a large nozzle having thousands of
holes or from a group of small nozzles each having 40 holes or so,
fibers can be produced through extrusion of a molten polymer. Here,
the fiber-ejecting amount per hole is preferably 0.1 to 1g/min,
more preferably 0.3 to 0.7 g/min. After discharged out of the
nozzle, the molten fibers are cooled in a cross-flow cold air
system. and thereafter separated from the nozzle and stretched by
high-speed air. In general, there are known two kinds of air
damping methods, and a venturi effect is used in both the two. The
first method is a method of stretching filaments using a suction
slot (slot stretching) in the nozzle width or the machine width.
The second method is for stretching filaments via a nozzle, or a
suction gun. The filaments formed according to this method are
collected on a screen (wire) or on a pore-forming belt to form a
web thereon. Next, the web passes through compression rolls, and
then passes between hot calender rolls (for example, a pair of
calender rolls of an emboss roll and a flat roll (also referred to
as S-roll)), in which the web bonds in the part where a rising part
of one roll includes an area of 10 to 40% of the web, thereby
forming a nonwoven fabric.
[0124] As the bonding mode, thermal bonding sue as embossing,
bonding with hot air, and calendaring; adhesive bonding; mechanical
bonding such as needle punching and water punching; etc., is
employable.
Multilayer Nonwoven Fabric of First Aspect or Second Aspect of
Invention
[0125] The spunbond nonwoven fabric of the first aspect or the
second aspect of the present invention may be a multilayer non
woven fabric produced by layering two or more layers. In the case,
it is desirable that at least one layer of the nonwoven fabric
constituting the outer layer of the multilayer nonwoven fabric is
the spunbond nonwoven fabric of the first aspect or the second
aspect of the present invention mentioned above.
[0126] The method for producing the multilayer non woven fabric is
not specifically limited, and the multilayer nonwoven fabric can be
produced in any known method. For example, first, a spunbond
nonwoven fabric of the first aspect or the second aspect of the
present invention is produced, and any other nonwoven fabric is
formed thereon according to a spun-bonding method, a melt-blowing
method or the like, and if desired, a spunbond nonwoven fabric of
the first aspect or the second aspect of the present invention or
any other nonwoven fabric is further layered thereon, and fused
with heating under pressure. The other nonwoven fabric is not
specifically limited, and a nonwoven fabric to be obtained
according to a known production method of a spun-bonding method, a
melt-blowing method, a spun-lacing method, a carding method or the
like may be employed. A melt-blown nonwoven fabric obtained
according to a melt-blowing method is preferred.
[0127] The layering means in producing the multilayer nonwoven
fabric includes various layering methods of thermal bonding,
adhesive bonding or the like, but a simple and inexpensive thermal
bonding layering method, especially a thermal embossing roll method
may also be employed. In the thermal embossing roll method,
nonwoven fabrics may be layered using a known layering device
including an embossing roll and a flat roll, like in the method of
using hot calender rolls mentioned above. For the embossing roll,
various types of embossing patterns may be employed, and the
bonding parts may have continuous grid-like patterns, independent
grid-like patterns or any random distribution patterns.
Fiber Product
[0128] Although the fiber product using the spunbond non woven
fabric of the first aspect, or the second aspect of the present
invention, and the fiber product using the above-mentioned
multilayer non woven fabric are not particularly limited, the
following fiber products may be exemplified. That is, there may be
exemplified a member for a disposable diaper, a stretchable member
for a diaper cover, a stretchable member for a sanitary product, a
stretchable member for a hygienic product, a stretchable tape, an
adhesive bandage, a stretchable member for clothing, an insulating
material for clothing, a heat insulating material for clothing, a
protective suit, a hat, a mask, a glove, a supporter, a stretchable
bandage, a base fabric for a fomentation, a non-slip base fabric, a
vibration absorber, a finger cot, an air filter for a clean room,
an electret filter subjected to electret processing, a separator, a
heat insulator, a coffee bag, a food packaging material, a ceiling
skin material for an automobile, an acoustic insulating material, a
cushioning material, a speaker dust-proof material, an air cleaner
material, an insulator skin, a backing material, an adhesive
nonwoven fabric sheet, various members for automobiles, such as a
door trim, etc., various cleaning materials, such as a cleaning
material for a copying machine, the facing and backing of a carpet,
an agricultural beaming, a timber drain, members for shoes, such as
a sport shoe skin, etc., a member for a bag, an industrial sealing
material, a wiping material, a sheet, etc.
Third Aspect of Invention
Nonwoven Fabric Formed of Composite Fibers
[0129] The nonwoven fabric formed of composite fibers of the third
aspect of the present invention is a nonwoven fabric formed of
composite fibers containing the following first component and
second component:
[0130] The first component is an olefin-based resin composition (I)
containing an olefin-based polymer (i) satisfying the following
requirements (a) and (b):
[0131] (a) The melt now rate (MFR) thereof, as measured under the
condition of a temperature of 230.degree. C. and a load of 21.18 N
is 1,000 g/10 min or more;
[0132] (b) The melting endothermic amount .DELTA.H-D, as measured
from the melting endothermic curve drawn by keeping the composition
at -10.degree. C. in a nitrogen atmosphere for 5 minutes and then
heating it at 10.degree. C./min in a nitrogen atmosphere using a
differential scanning calorimeter (DSC), is less than 80 J/g.
[0133] The second component is an olefin-based resin composition
(II) containing an olefin-based polymer (ii) satisfying the
following requirements (e) and (f):
[0134] (e) The melt flow rate (MFR) thereof, as measured under the
condition of a temperature of 230.degree. C. and a load of 21.18 N
is 1 g/10 min or more and 100 g/10 min or less;
[0135] (f) The melting point (Tm-D), as defined as a peak top of a
peak observed on the highest temperature side of the melting
endothermic curve drawn by keeping the composition at -10.degree.
C. in a nitrogen atmosphere for 5 minutes and then heating it at
10.degree. C./min in a nitrogen atmosphere using a differential
scanning calorimeter (DSC), is higher than 120.degree. C.
[0136] Here in this description, "composite fiber" is used to
include "core-sheath type fiber" of a fiber in which the cross
section of the fiber is composed of "core" of an inner layer part
and "sheath" of an outer layer part, and "crimped fiber" of a fiber
of a combination of thermoplastic resins that differ in thermal
shrinkage. "Crimped fiber" is used to include "side-by-side type
fiber" and "eccentric core-sheath type fiber". "Side-by-side type
fiber" is a fiber obtained by melt-extruding at least two kinds of
resins, bonding and spinning the at least two types of resins. The
form of the crass section of the side-by-side type fiber is not
limited to a substantially circular ne (including "true circle),
but in consideration of the bulkiness of the fiber, the form may be
an oval one, a daruma-like (cocoon-like) one or the like, but from
the viewpoint of popularity, the form is preferably a true
circle.
[0137] "Substantially circular one" means that the ratio of the
lengths of the two axes crossing at 90.degree. in the center of the
cross section of the fiber is about 1.2/1 or less, and "true
circle" means that the ratio of the lengths of the two axes
crossing at 90.degree. in the center of the cross section of the
fiber is about 1/1. "Oval" means that the ratio of the lengths of
the two axes crossing at 90.degree. in the center of the cross
section of the fiber is larger than about 1.2/1; and "daruma-like
form" means a cross-section form of such that plural axes passing
through the center of the cross section of the fiber each have a
short axis and a long axis, and when the length of the long axis
relative to the length of the short axis is plotted, the resultant
curve has at least two maximum values.
[0138] The ratio of at least two kinds of resins that occupy the
cross section of the side-by-side type fiber is determined
depending on the extrusion ratio of the resins in melt
extrusion.
[0139] "Eccentric core-sheath type fiber" indicates a fiber of such
that, in the cross-section form of the eccentric core-sheath type
fiber, the position of the center of gravity of the inner layer
part differs from the position of the center of gravity of the
whole fiber, and is formed using a composite nozzle which is so
arranged that the position of the center of gravity of the inner
layer part could differ from the position of the center of gravity
of the whole fiber, for example, using an eccentric core-sheath
type composite nozzle.
[0140] The ratio of at least two kinds of resins that occupy the
cross section of the eccentric core-sheath type fiber is determined
depending on the extrusion ratio of the resins in melt
extrusion.
[0141] In the case where the first component is used for the core
part of the core-sheath type fiber, the second component may be
used for the sheath part; and in the case where the second
component is used for the core part of the core-sheath type fiber,
the first component may used for the sheath part.
First Component
[0142] The first component, is the olefin-based resin composition
(I) that contains the olefin-based polymer (i) satisfying the
above-mentioned requirements (a) and (b).
[0143] The requirements (a) and (b) are the sane as those described
for the spunbond nonwoven fabric of the first aspect of the
invention and for the spunbond nonwoven fabric of the second aspect
of the invention, and the preferred embodiments thereof are also
the same. In addition, the constituent components usable for the
olefin-based polymer (i) and the olefin-based resin composition (I)
are the same as those described for the spunbond nonwoven fabric of
the first aspect of the invention and for the spunbond nonwoven
fabric of the second aspect of the invention, and the preferred
embodiments thereof are also the same, unless otherwise
specifically indicated.
[0144] The content of the olefin-based polymer in the olefin-based
resin composition (I) is, relative to the total amount 100% by mass
of the olefin-based resin composition (I), preferably 50% by mass,
more preferably 3 to 45% by even more preferably 0 to 40% by mass.
When the content of the olefin-based polymer (i) in the
olefin-based resin composition (I) is 50% by mass or less, the
crystallization speed on the spinning line is not extremely low and
the spinnability is therefore stabilized. On the other hand, when
the content of the olefin-based polymer (i) in the olefin-based
resin composition (I) is 1% by mass or more, the fibers to be
formed may be thinned, and with the reduction in the elastic
modulus of the fibers, the flexibility of the nonwoven fabric to be
formed is therefore bettered.
Second Component
[0145] The second component is the olefin-based resin composition
(II) that contains the olefin-based polymer (ii) satisfying the
following requirements (e) and (f).
[0146] (e) The melt flow rate (MFR) thereof, as measured under the
condition of a temperature of 230.degree. C. and a load of 21.18 N
is 1 g/10 min or more and 100 g/10 min or less.
[0147] (f) The melting point (Tm-D), as defined as a peak top of a
peak observed on the highest temperature side of the melting
endothermic curve drawn by keeping the composition at -10.degree.
C. in a nitrogen atmosphere for 5 minutes and then heating it at
10.degree. C./min in a nitrogen atmosphere using a differential
scanning calorimeter (BSC), is higher than 120.degree. C.
[0148] Regarding the olefin-based polymer (ii) for use in the third
aspect of the present invention, MFR thereof, as measured at a
temperature of 230.degree. C. and under a load of 21.18 N is 1 g/10
min or more and less than 100 g/10 min, preferably 10 g/10 min or
more and 90 g/10 min or less, more preferably 15 g/10 min or more
and 80 g/10 min or less, still more preferably 20 g/10 min or more
and 70 g/10 min or less.
[0149] The melt flow rate (MFR) is a value measured according to
the measurement method stipulated in JIS K7210, using an
extrusion-type plastometer defined in JIS K6760.
[0150] The olefin-based polymer (ii) for use in the third aspect of
the present invention is not particularly limited so long as its
melting point (Tm-D) defined as a peak top of a peak observed on
the highest temperature side of the melting endothermic curve
obtained by holding under a nitrogen atmosphere at -10.degree. C.
for 5 minutes and then increasing the temperature at a rate of
10.degree. C./min under a nitrogen atmosphere by using a
differential scanning calorimeter (DSC) exceeds 120.degree. C.
High-crystalline polypropylenes such as PP3155 (trade name,
manufactured by ExxonMobil Chemical), Y2005GP (trade name,
manufactured by Prime Polymer Co., Ltd.), Prime Polypro.TM. S119
(trade name, manufactured by Prime Polymer Co., Ltd.), NOVATEC-SA03
(trade name, manufactured by Japan Polypropylene Corporation) and
the like may be used.
[0151] The olefin-based polymer (ii) may be either a propylene
homopolymer or a copolymer. In the case of a copolymer, the
copolymerization ratio of the propylene unit is 50 mol % or more,
preferably 60 mol % or more, more preferably 70 mol % or more,
still more preferably 90 mol or more, and still, even more
preferably 95 mol % or more. Examples of copolymerizable monomers
include .alpha.-olefins having 2 or 4 to 20 carbon atoms, such as
ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, etc.,
acrylic esters, such as methyl acrylate, etc., vinyl acetate, and
the like. From the viewpoint of moldability, a propylene
homopolymer is preferred. One alone or two or more kinds of such
polymers may be used either singly or as combined.
[0152] As the olefin-based polymer (ii), one having a melting point
(Tm-D), defined as a peak top of a peak observed on the highest
temperature side of the melting endothermic curve obtained by
holding under a nitrogen atmosphere at -10.degree. C. for 5 minutes
and then increasing the temperature at a rate of 10.degree. C./min
under a nitrogen atmosphere by using a differential scanning
calorimeter (DSC), of higher than 120.degree. C. and 170.degree. C.
or lower is preferred, and one having the melting point of 125 to
167.degree. C. is more preferred.
[0153] In the case where the second component is the olefin-based
resin composition (II) containing the above-mentioned olefin-based
polymer (ii), the component may contain the above-mentioned
olefin-based polymer (i). In the case where the component contains
the olefin-based polymer (i), the content of the olefin-based
polymer (i) is less than the content of the olefin-based polymer
(i) in the olefin-based resin composition (I).
[0154] The olefin-based polymer (ii) is preferably a
propylene-based polymer (iip). Hereinunder in this description, the
mere expression of propylene-based polymer (iip) means the
propylene resin satisfying the above-mentioned requirements (e) and
(f).
[0155] The propylene-based resin not satisfying the requirements
includes, though not specifically limited thereto, the
above-mentioned propylene-based polymer (ip), etc.
[0156] The olefin-based resin composition (II) is preferably a
propylene-based resin composition (IIP). In this description, the
propylene-based resin composition (IIP) indicates an olefin resin
composition of the above-mentioned olefin-based resin composition
(II) where the proportion of the propylene-based polymer (iip) is
50% by mass or more.
[0157] The proportion of the propylene-based polymer (iip) in the
olefin-based resin composition (II) is preferably 85% by mass or
more, more preferably 90% by mass or more, even more preferably 95%
by mass or more.
[0158] Hereinunder in this description, the expression of
propylene-based resin composition (IIP) indicates the
propylene-based resin composition that contains the olefin-based
polymer (ii) satisfying the above-mentioned requirements (e) and
(f) for use in the third aspect of the present invention.
[0159] The other polypropylene in the above-mentioned first
component and the propylene-based polymer (iip) in the second
component may be the same resin or may be suitably selected from
different resins, in accordance with the crimping degree and the
elongation ratio of the crimped fibers.
[0160] The olefin-based resin composition (II) may contain any
other thermoplastic resin and various additives such as release
agent and the like, within a range not detracting from the
advantageous effects of the third aspect of the present
invention.
[0161] The other thermoplastic resin includes olefin polymers
except the olefin-based polymer (i) and the olefin-based polymer
(ii), concretely polypropylene, propylene-ethylene copolymer,
propylene-ethylene-diene copolymer, polyethylene,
ethylene-.alpha.-olefin copolymer, ethylene-vinyl acetate
copolymer, hydrogenated styrenic elastomer, etc. There are also
mentioned polyester, polyamide, polylactic acid, etc. These
polymers may be employed singly or in combination of two or more
species.
[0162] As the release agent and various additives except release
agent, there are mentioned the same as those described hereinabove
for the release agent and various additives that may be contained
in the olefin-based resin composition (I) for the first aspect and
the second aspect of the present invention mentioned above.
Relation between First Component and Second Component
[0163] In the third aspect of the present invention, it is
preferred that the first component and the second component are
provided with the following relation.
[0164] In the case of the crimped fiber among the composite fibers
for use in the third aspect of the present invention, the melt flow
rate (MFR) of the olefin-based resin composition (I) that
constitutes the first component preferably differs from the melt
flow rate (MFR) of the olefin-based resin composition (II) that
constitutes the second component.
[0165] Here, the melt flow rate (MFR) of the olefin-based resin
composition (I) constituting the first component and that of the
olefin-based resin composition (II) constituting the second
component are values measured at a temperature of 230.degree. C.
and a load of 21.18 N by using an extrusion-type plastometer
prescribed in JIS K6760 by the measurement method in conformity
with JIS K7210.
[0166] In the above-described relation of the melt flow rate (MFR),
as a difference in the MFR between the both components is large,
the high crimping crimping performance are revealed. However,
taking into consideration other physical properties, such as fiber
strength, etc., the olefin-based resin composition (I) that is the
first component, and the olefin-based resin composition (II) that
is the second component, are properly selected in view of the
above-described relation.
[0167] MFR of the olefin-based resin composition (I) for use in the
third aspect of the present invention is 2,000 g/10 min or less,
preferably 10 to 1,500 g/10 min more preferably 15 to 1,000 g/10
min, even more preferably 18 to 900 g/10 min.
[0168] In the case where the nonwoven fabric formed of composite
fibers is a crimped spunbond nonwoven fabric, MFR of the
olefin-based resin composition (I) is preferably 30 to 200 g/10
min, more preferably 50 to 150 g/10 min, even more preferably 60 to
100 g/10 min.
[0169] On the other hand, in the case of the crimped fibers among
the composite fibers for use in the third aspect of the present
invention, MFR of the olefin-based resin composition (II)
preferably satisfies the relation to MFR between the first
component and the second component, and in consideration of the
preferred range of MFR of the olefin-based resin composition (I) of
the first component, MFR of the olefin resin composition (II) is
2,000 g/10 min or less, preferably 10 to 1,500 g/10 min, more
preferably 15 to 1,000 g/10 min, even more preferably 18 to 900
g/10 min.
[0170] In the case where the nonwoven fabric formed of composite
fibers is a crimped spunbond nonwoven fabric, MFR of the
olefin-based resin composition (II) is preferably 1 to 100 g/10
min, more preferably 10 to 70 g/10 min, even more preferably 20 to
50 g/10 min.
[0171] Accordingly, in the case of producing crimped fibers, fibers
having strong crimping performance can be obtained without an post
treatment such as stretching or heating after the resin of the
first component and the resin of the second component are bonded,
extruded and spun through conventional melt extrusion. Heretofore,
in consideration of the materials for use in production crimped
fibers and the physical properties thereof, the post-treatment step
after spinning is indispensable, and depending on the
post-treatment condition for stretching, heating and the like, the
crimping degree may often vary. Consequently, in the case where the
composite, fibers for use in the third aspect of the present
invention roped fibers, the post treatment is not indispensable,
and therefore fibers having a stable crimping degree can be
obtained, and in addition, owing to reduction in the number of the
processing steps, the production cost can be reduced and the
production apparatus can be down-sized.
[0172] In the composite fibers for use in the third aspect of the
present invention, the ratio by mass of the olefin-based resin
composition (I) of the first component/the olefin-based resin
composition (II) of the second component is 10/90 to 90/10,
preferably 20/80 to 80/20, more preferably 30/70 to 70/30. When the
ratio by mass within a range of 10/90 to 90/10, the case of
core-sheath type fibers can express flexibility anti the case of
crimped fibers can express crimping performance and stretching
performance.
[0173] Further, when the first component contains the
propylene-based polymer (i) in an amount falling within a range of
1% by mass or more and 50% by mass or less, and when the ratio by
mass of the propylene-based resin composition (IP) of the first
component/the propylene-based resin composition (IIP) of the second
component is 10/90 to 90/10, the case of core-sheath type fibers
can express flexibility and the case of crimped fibers is excellent
in the balance of crimping performance, stretching performance and
flexibility.
[0174] In the composite fibers for use in the third aspect of the
present invention, any conventional known additive may be
incorporated in at least one of the first component and the second
component. In addition, at least one of the first component and the
second component may further contain an internal release agent.
[0175] As the internal release agent and the other additives than
the internal release agent, the same as those of the release agent
and other various additives that the olefin-based resin composition
(I) described in the section of the first aspect and the second
aspect of the present invention may contain are referred to.
[0176] The content of the internal release agent is, based on the
composition of the first component or the second component
containing the internal release agent, preferably 10 to 10,000 ppm
by mass, more preferably 100 to 5,000 ppm by mass. When the content
of the internal release agent is 10 ppm by mass or more, the
function as the release agent is revealed, whereas when it is
10,000 ppm by mass or less, the balance between the function of the
release agent and the economic potential thereof is good.
[0177] In the nonwoven fabric formed of composite fibers of
side-by-side fibers, the viscosity difference between the two
components constituting the fibers is large, and in the case where
the crystallization speed of the first component and that of the
second component are both high, the fibers rapidly crimped just
below the stretching process (ejector or cabin) for the fibers in
the production method for the fibers to be described below. At this
time, there is a concern that a roping phenomenon in which fibers
are entangled with each other is revealed, whereby uniformity
(uniformity of the appearance) of the nonwoven fabric is
impaired.
[0178] Therein one embodiment of the third aspect of the present
invention, the present inventors have found that, by adding the
propylene-based polymer (i) to the first component of the
side-by-side fibers, it becomes possible to suppress the generation
of the roping phenomenon following abrupt crimping just beneath the
stretching step of fibers, and a nonwoven fabric of crimped fibers
excellent in a balance between crimping performance and formation
uniformity can be obtained.
Production Method for Composite Fibers, and Nonwoven Fabric Formed
of Composite Fibers
[0179] Embodiments of the production method for composite fibers
for use in the third aspect of the present invention and the
production method for the non woven fabric formed of composite
fibers are described below.
[0180] In one example of the production method for the composite
fibers for use in the third aspect of the present invention, the
resin components constituting the composite fibers may be melted in
different extruders or the like. The resin extrusion amount of each
resin component is suitably controlled, and the melts are ejected
out through a spinning spinneret having a composite spinning nozzle
as so designed that each melt can be ejected to form a desired
structure (for example, core-sheath type (non-eccentric type),
eccentric core-sheath type, side-by-side type, etc.), and spun into
composite fibers. The spun composite fibers are optionally cooled
with a cooling fluid, and further the core-sheath type fibers are
given tension by stretching air or by a winding machine to have a
predetermined fiber fineness. The temperature of the stretching air
may be lower than the resin melt temperature, or the fibers may be
stretched with high-temperature air.
[0181] In the case where a non woven fabric of the core-sheath type
fibers is produced, the core-sheath type fibers may be directly
collected on a collecting belt and deposited thereon to have a
predetermined thickness, and are thereafter processed for
entanglement to produce the intended nonwoven fabric.
Production Method for Core-Sheath Type Fibers, and Nonwoven Fabric
Formed of Core-Sheath Type Fibers
[0182] Embodiments of the production method for the core-sheath
type fibers that can be used as the composite fibers for use in the
third aspect of the present invention and the production method for
the nonwoven fabric formed of the core-sheath type fibers are
described below.
[0183] In an example of the production method for the core-sheath
type fibers for use in the third aspect of the present invention,
first, the component to constitute the core and the component to
constitute the sheath are separately melted in different extruders
or the like. While the resin ejecting amount of each component is
suitably controlled, the melts are ejected through a spinning
spinneret having a composite spinning nozzle as so designed that
each melt can be ejected to form a desired core-sheath structure,
and spun into core-sheath type composite fibers. The spun
core-sheath type composite fibers are optionally cooled with a
cooling fluid, and further the fibers are given tension by
stretching air or by a winding machine to have a predetermined
fiber fineness. The temperature of the stretching air may be lower
than the resin melt temperature, or the fibers ma be stretched with
high-temperature air.
[0184] In the case where a nonwoven, fabric of the core-sheath type
fibers is produced, the core-sheath type fibers may be directly
collected on a collecting belt and deposited thereon to have a
predetermined thickness, and are thereafter processed for
entanglement to produce the intended nonwoven fabric.
Production Method for Side-by-Side Fibers, and Nonwoven Fabric
Formed of Side-by-Side Type Fibers
[0185] Embodiments of the production method for the side-by-side
type fibers that can be used as the composite fibers for use in the
third aspect of the present invention and the production method for
the nonwoven fabric formed of the side-by-side type fibers are
described below.
[0186] In an example of the production method for the side-by-side
type fibers for use in the third aspect of the present invention,
first, at least two resin components are separately melted in
different extruders or the like, and while the resin ejecting
amount of each component is suitably controlled, the resin melts
are extruded out. For example, the resin melts are extruded from
special spinning nozzles as disclosed in, for example, U.S. Pat.
No. 3,671,379. The resin melts thus melt-extruded through different
extruders are joined and discharged to be fibers, followed by
cooling for solidification. Examples of the production method
employable for the process of cooling fibers and stretching them
are the same as those of the production method for the core-sheath
type fibers described hereinabove.
[0187] Here, the discharge speed, the stretching air during
spinning and the take-off wind-up speed are property set depending
upon the physical properties of the resins, the mass ratio of the
resin components tin the case where the resin components are two
components, the physical properties of the two components and the
mass ratio thereof, etc.).
[0188] In the case where a nonwoven fabric formed of the
side-by-side type fibers is produced, the side-by-side type fibers
may be directly collected on a collecting belt and deposited
thereon to have a predetermined thickness, and are thereafter
processed for entanglement to produce the intended nonwoven
fabric.
[0189] In the production method for the side-by-side type fibers
for use in the third aspect of the present invention, the desired
fibers may be produced even without performing a post-treatment
step, such as heating or stretching after spinning, etc.; however,
the above-described post-treatment step may be adopted, if desired.
For example, the crimping degree of the fibers may be increased by
heating at 100 to 150.degree. C., stretching in a ratio of 1.2 to 5
times, or a combined condition thereof.
[0190] In one embodiment of the present invention, in the
side-by-side type fibers for use in the third aspect of the
invention, the above-described propylene-based polymer (i) is
compounded in only the first component, but the present invention
is not limited thereto. The above described propylene-based polymer
(i) may also be added to the second component according to the
melting point and the physical properties of the propylene-based
polymer (i) to be added, as so described hereinabove.
[0191] As for the side-by-side type fibers constituting the crimped
nonwoven fabric of the third aspect of the present invention, the
fineness thereof as calculated by the following measuring method is
preferably 0.5 deniers or more and 2.5 deniers or less, and more
preferably 0.8 to 2.0 deniers from the viewpoints of the balance
between the texture, the flexibility and the strength of the
nonwoven fabric. The crimped nonwoven fabric of third aspect of the
present invention is small in terms of the fineness as described
above and is excellent in terms of spinning stability even under
forming conditions under which thread breakage likely occurs.
[0192] The value of fineness is a value obtained according to the
method described in the section of Examples given hereinunder.
Production Method for Eccentric Core-Sheath Type Fibers, and
Nonwoven Fabric Formed of Eccentric Core-Sheath Type Fibers
[0193] Embodiments of the production method for the eccentric
core-sheath type fibers that can be used as crimped fibers in the
third aspect of the present invention, and the production method
for the nonwoven fabric formed of the eccentric core-sheath type
fibers are the same as those of the production method for the
core-sheath type fibers and for the nonwoven fabric formed of the
core-sheath type fibers described hereinabove, except that an
eccentric core-sheath type nozzle is used in place of the
core-sheath composite nozzle, and therefore the detailed
description thereof is omitted here.
[0194] The nonwoven fabric formed of the composite fibers of the
third aspect of the present invention can be prepared by cutting
the composite fibers capable of being used in the third aspect of
the present invention to give short fibers, followed by processing
the resultant short fibers according to a carding method or
spunlacing method, or further through chemical bonding or thermal
bonding. Further, in the case where the composite fibers are
crimped fibers, the nonwoven fabric of continuous fibers produced
by air-stretching or the nonwoven fabric of short fibers is first
produced, and then the crimping degree of the fibers in the
nonwoven fabric may be increased by further stretching or
heating.
[0195] In the case of producing a nonwoven fabric, fiber bundles
layered on a net surface are subjected to thermal press bonding to
form the nonwoven fabric. When the heating temperature is
excessively high, sufficient bulkiness is not obtained, whereas
when the heating temperature is low, fusion of the fibers is not
sufficient, so that it may be expected that fluffing is generated.
As for the nonwoven fabric formed of the composite fibers of the
third aspect of the present invention, it is possible to form a
nonwoven fabric at a heating temperature that is a relatively low
temperature as 20.degree. C. to 100.degree. C., sufficient
bulkiness is obtained, and a fluffing-free nonwoven fabric may be
obtained.
[0196] In the case where an embossing area ratio is small, even if
the embossing temperature is not a relatively low temperature, it
is possible to obtain a nonwoven fabric that is bulky and free from
fluffing.
[0197] Here, the "embossing area ratio" refers to an occupation
ratio of an embossed pattern area per unit area.
Multilayer Nonwoven Fabric of Third Aspect of Invention
[0198] The nonwoven fabric formed of composite fibers of the third
aspect of the present invention is a spunbond nonwoven fabric using
the above-mentioned core-sheath type fibers and/or crimped fibers
(any of side-by-side type fibers or eccentric core-sheath type
fibers), and may be a multilayer nonwoven fabric produced by
layering with various layers depending on the use thereof or by
layering two or more layers. In this case, from the viewpoint of
surface smoothness, it is desirable that at least one nonwoven
fabric layer to constitute the outer layer of the multilayer
nonwoven fabric is the above-mentioned spunbond nonwoven
fabric.
[0199] Specifically, examples of various layers include a knitted
fabric, a woven fabric, a nonwoven fabric, a film, etc. As a method
of layering the fibrous nonwoven fabric with any other layer (by
bonding), various known method are employable, including a thermal
fusion bonding method of thermal embossing, ultrasonic fusion
bonding or the like, a mechanical entangling method of needle
punching, water-jet treatment or the like, a method of using an
adhesive such as a hot-melt adhesive, an urethane adhesive or the
like, and an extrusion lamination method, etc. A simple and
inexpensive thermal adhesion layering method, especially a thermal
embossing roil method is also employable. In the thermal embossing
roll method, the fabrics may be layered using a known layering
device equipped with an embossing roll and a flat roll, like in the
above-mentioned thermal calendering roll method. For the embossing
roll, various types of embossing patterns are employable, and the
bonding parts may have continuous grid-like patterns, independent
grid-like patterns or any random distribution patterns.
[0200] For example, there may be mentioned a method where a
nonwoven fabric formed of composite fibers of the third aspect of
the present invention is first produced, and any other nonwoven
fabric is formed thereon according to a spunbonding method, a
melt-blowing method or the like, and optionally a nonwoven fabric
formed of composite fibers of the third aspect of the present
invention or any other nonwoven fabric is further laminated
thereon, and then bonded by heating under pressure. As the other
nonwoven fabric, any other nonwoven fabric than the nonwoven fabric
of the third aspect of the present invention including, though not
specifically limited thereto, a spunbond nonwoven fabric, a
melt-blown nonwoven fabric, a wet-process nonwoven fabric, a
dry-process nonwoven fabric, a dry-process pulp nonwoven fabric, a
flash-spinning nonwoven fabric, an open fiber nonwoven fabric and
the like, may be used. From the viewpoint of formation uniformity,
a melt-blown nonwoven fabric to be produced according to a
melt-blowing method is preferred.
[0201] The material to constitute other nonwoven fabric than the
nonwoven fabric of the third aspect of the present invention
includes various known thermoplastic resins, and examples thereof
include polyolefins such high-pressure process low-density
polyethylene, linear low-density polyethylene (so-called LLDPE)
polyethylene, polypropylene, polypropylene random copolymer,
poly-1-butene, poly-4-methyl-1-pentene ethylene-propylene random
copolymer, ethylene-1-butene random copolymer, propylene-1-butene
random copolymer and others that are homo or copolymers of
.alpha.-olefins such as ethylene, propylene, 1-butene, 1-hexene,
4-methyl-1-pentene, 1-octene or the like; polyesters (polyethylene
terephthalate, polybutylene terephthalate, polyethylene
naphthalate, etc.), polyamides (nylon-6, nylon-66,
polymetaxyleneadipamide, etc.), polyvinyl chlorides, polyimides,
ethylene-vinyl acetate copolymers, polyacrylonitriles,
polycarbonates, polystyrenes, ionomers, thermoplastic
polyurethanes, their mixtures, etc. Among these, high-pressure
process low-density polyethylene, linear low-density polyethylene
(so-called LLDPE), high-density polyethylene, polypropylene,
polypropylene random copolymer, polyethylene terephthalate,
polyamide and the like are preferred.
[0202] As the film to be layered with the nonwoven fabric formed of
composite fibers of the third aspect of the present invention, an
air permeable (moisture permeable) film capable of taking advantage
of the air permeability that is a characteristic feature of the
nonwoven fabric formed of composite fibers of the third aspect of
the present invention, is preferred. As the air permeable film,
various known air permeable films are usable, and examples thereof
include a film of a moisture permeable thermoplastic elastomer such
as polyurethane-based elastomer, polyester-based elastomer,
polyamide-base elastomer, etc., a porous film produced by
stretching a film of a thermoplastic resin containing inorganic or
particles to make the film porous. The thermoplastic resin for the
porous film is preferably a polyolefin such as high-pressure
process low-density polyethylene, linear low-density polyethylene
(so-called LLDPE), high-density polyethylene, polypropylene,
polypropylene random copolymer or a composition thereof, etc.
[0203] The laminate with the air-pervious film can be a cloth
composite material that takes advantage of bulkiness and
flexibility of the nonwoven fabric of composite fibers of the third
aspect of the present invention and has extremely high
waterproofness.
Fiber Product
[0204] As examples of the fiber products using the nonwoven fabric
of composite fibers of the third aspect of the present invention
and the fiber products using the multilayer nonwoven fabric of the
third aspect of the present invention, the same as those of the
fiber products for the first aspect and the second aspect of the
present invention that have been described hereinabove are referred
to, though not specifically limited thereto. In the case whore
crimped fibers are used as the composite fibers, the fiber products
can be used as heat-insulating materials from the viewpoint that
the crimped nonwoven fabric is formed of bulky fibers having a high
crimpling degree and a high stretching degree and secures
air-retentive performance and heat-insulating performance.
EXAMPLES
[0205] The present invention is described in more detail with
reference to Examples and Comparative Examples given below;
however, the present invention is not whatsoever restricted by the
description of these Examples.
Production Examples 1 to 3
[0206] Into a stirrer-equipped stainless steel-made reactor having
an internal volume of 0.25 m.sup.3, 26 L/h of n-heptane, 7.7 mmol/h
of triisobutylaluminum, and further a catalyst component obtained
by previously bringing dimethylanilinium
tetrakis(pentafluorophenyl)borate,
(1,2'-dimethylsilylene(2,1'-dimethylsilylene)-bis(3-trimethylsilymethylin-
denyl)zirconium dichloride, triisobutylaluminum, and propylene into
contact with each other were continuously supplied. Propylene and
hydrogen were continuously supplied so as to keep a whole pressure
within the reactor to 1.0 MPaG, and a polymerization temperature
was properly adjusted to obtain a polymerization solution having a
desired molecular weight. To the resulting polymerization solution,
an antioxidant was added in an amount of 1,000 ppm by mass, and the
solvent was removed to give a propylene-based polymer (1), (2) and
(3).
[0207] The physical properties of the propylene polymer are shown
in Table 1 below.
[0208] The physical properties of the propylene-based polymer and
the physical properties of the propylene-based resin composition
used in Examples and Comparative Examples were determined according
to the measurements mentioned below.
Melt Flow Rate (MFR)
[0209] Measured at a temperature of 230.degree. C. and under a load
of 21.18 N according to JIS K7210:1999.
Melting Endothermic Amount (.DELTA.H-D)
[0210] Using a differential scanning calorimeter (manufactured by
Perkin Elmer Inc., trade name "DSC-7"), 10 mg of the sample was
kept at -10.degree. C. in a nitrogen atmosphere for 5 minutes and
then heated at 10.degree. C./min in a nitrogen atmosphere, and from
the resultant melting endothermic curve, the melting endothermic
amount .DELTA.H-D was determined.
Measurement of .sup.13C-NMR Spectrum
[0211] The .sup.13C-NMR spectrum was measured with the following
device under the following conditions in accordance with the
assignment of the peak, as proposed by A. Zambelli, et al.,
"Macromolecules, 8, 687 (1975)".
[0212] Device: .sup.13C-NMR device, "JNM-EX400 Model", manufactured
by JEOL, Ltd.
[0213] Method: Proton complete decoupling method
[0214] Concentration: 220 mg/mL
[0215] Solvent: Mixed solvent of 1,2,4-trichlorobenzene and
deuterated benzene in a ratio of 90/10 (volume ratio)
[0216] Temperature: 130.degree. C.
[0217] Pulse width: 45.degree.
[0218] Pulse repetition time: 4 seconds
[0219] Accumulation: 10,000 times
Calculating Expressions
[0220] M=m/S.times.100
R=.gamma./S.times.100
S=P.beta..beta.+P.alpha..beta.+P.alpha..gamma.
S: Signal intensity of carbon atoms in side chain methyl of all the
propylene units
P.beta..beta.: 19.8 to 22.5 ppm
P.alpha..beta.: 18.0 to 17.5 ppm
P.alpha..gamma.: 17.5 to 17.1 ppm
[0221] .gamma.: Racemic pentad chain, 20.7 to 20.3 ppm m:
Mesopentad chain, 21.7 to 22.5 ppm
TABLE-US-00001 TABLE 1 Production Production Production Example 1
Example 2 Example 3 Propylene-based polymer (1) (2) (3) MFR (g/10
min) 2000 350 50 Melting endothermic amount 38 35 37 .DELTA.H - D
(J/g) [mmmm] (mol %) 47.7 49.0 49.7 [rrrr]/(1 - [mmmm]) 0.05 0.05
0.05
Production of Spunbond Nonwoven Fabric
[0222] Next, Examples and Comparative Examples of nonwoven fabrics
using the above-mentioned materials and other polypropylenes are
described.
Example 1
[0223] 10% by mass of the propylene-based polymer (1) obtained in
Production Example 1, 86% by mass of "NOVATEC-SA03" (trade name,
manufactured by Nippon Polypropylene Corporation, MIR 30 g/10 min,
melting point: 160.degree. C.), and 4% by mass of an erucamide
master batch prepared by mixing 95% by mass of "Y6005GM" (trade
name manufactured by Primer Polymer Co., Ltd., MFR: 60 g/10 min)
and 5% by mass of erucamide (2,000 ppm by mass, based on the
propylene-based resin composition, of erucamide was added) were
mixed to prepare a propylene-based resin composition.
[0224] The propylene-based resin composition was melt-extruded at a
resin temperature of 200.degree. C. using a single-screw extruder
having a gear pump, and the molten resin was discharged through a
nozzle having a diameter of 0.5 mm (number of holes, 2,675) at a
single bole discharge rate of 0.4 g/min/hole to thereby carry out
spinning. While the fibers produced through spinning were cooled
with cold air at 12.5.degree. C. and at a rate of 0.3 m/sec, the
fibers were aspirated under a pressure of 1.0 kg/cm.sup.2 by means
of an ejector below the nozzle, to thereby stack the fibers onto a
net surface moving at a line speed of 119 m/min.
[0225] The fiber bundles stacked on the net surface were subjected
to embossing by means of a calender roll heated at 135.degree. C.
under a nip pressure of 40 N/mm, and then wound around a take-up
roll.
[0226] The basis weight of the resultant spunbond nonwoven fabric
was measured and the uniformity of formation thereof was evaluated
according to the methods mentioned below. The measurement results
are shown in Table 2.
Comparative Example 1
[0227] A spunbond nonwoven fabric was produced in the same manner
as in Example 1 except that the propylene-based resin composition
was prepared by mixing 1.0% by weight of the propylene-based
polymer (2) produced in Production Example 2, 86% by mass of
"NOVATEC-SA03" manufactured by Nippon Polypropylene Corporation,
and 4% by mass of the erucamide master batch prepared in the same
manner as in Example 1 (2,000 ppm by mass, based on the
propylene-based resin composition, of erucamide was added), and the
resultant nonwoven fabric was analyzed. The measurement results are
shown in Table 2.
Comparative Example 2
[0228] A spunbond nonwoven fabric was produced in the same manner
as in Example 1 except that the propylene-based resin composition
was prepared by mixing 10% by weight of the propylene-based polymer
(3) produced in Production Example 3, 86% by mass of "NOVATEC-SA03"
manufactured by Nippon. Polypropylene Corporation, and 4% by mass
of the erucamide master batch prepared in the same manner as in
Example 1 (2,000 ppm by mass, based on the propylene-based resin
composition, of erucamide was added), and the resultant nonwoven
fabric was analyzed. The measurement results are shown in Table
2.
Comparative Example 3
[0229] A spunbond nonwoven fabric was produced in the same manner
as in Example 1 except that the propylene-based resin composition
was prepared by mixing 96% by mass of "NOVATEC-SA03" manufactured
by Nippon Polypropylene Corporation and 4% by mass of the erucamide
master batch prepared in the same manner as in Example 1 (2,000 ppm
by mass, based on the propylene-based resin composition, of
erucamide was added), and the resultant nonwoven fabric was
analyzed. The measurement results are shown in Table 2.
Reference Example 1
[0230] A nonwoven fabric was produced in the same manner as in
Example 1 except that resin composition was melted at 240.degree.
C. and extruded, and the resultant nonwoven fabric was analyzed.
The measurement results are shown in Table 2.
Comparative Example 4
[0231] A nonwoven fabric was produced in the same manner as in
Reference Example 1 except that the propylene-based resin
composition was prepared by mixing 5% by mass of the
propylene-based polymer (3) produced in Production Example 3, 5% by
mass of propylene-ethylene copolymer (1) "Vista maxx 6202" (trade
name, manufactured by Exxon Mobile Chemical, MFR: 19 g/10 min,
.DELTA.H-D: 19 J/g), 86% by mass of "NOVATEC-SA03" manufactured by
Nippon Polypropylene Corporation, and 4% by mass of the erucamide
master batch prepared in the same manner as in Example 1 (2,000 ppm
by mass, based on the propylene-based resin composition, of
erucamide was added), the cooling air in spinning was at
20.0.degree. C. and at 1.0 m/sec, and the suction pressure of the
ejector was 3.0 kg/cm.sup.2, and the resultant nonwoven fabric was
analyzed. The measurement results are shown in Table 2.
Comparative Example 5
[0232] A nonwoven fabric was produced in the same manner as in
Comparative Example 4 except that the propylene-based resin
composition was prepared by mixing 2% by mass of the
propylene-based polymer (3) produced in Production Example 3, 8% by
mass of propylene-ethylene copolymer (1) "Vistamaxx 6202" (trade
name, manufactured by Exxon Mobile Chemical, MFR: 19 g/10 min,
.DELTA.H-D: 19 J/g), 86% by mass of "NOVATEC-SA03" manufactured by
Nippon Polypropylene Corporation, and 4% by mass of the erucamide
master batch prepared in the same manner as in Example 1 (2,000 ppm
by mass, based on the propylene-based resin composition, of
erucamide was added), and the suction pressure of the ejector in
spinning was 3.5 kg/cm.sup.2, and the resultant nonwoven fabric was
analyzed. The measurement results are shown in Table 2.
TABLE-US-00002 TABLE 2 Comparative Comparative Comparative Unit
Example 1 Example 1 Example 2 Example 3 Propylene- Components
Propylene-based polymer (1) mass % 10 0 0 0 based resin
Propylene-based polymer (2) mass % 0 10 0 0 composition
Propylene-based polymer (3) mass % 0 0 10 0 Propylene-ethylene
copolymer (1) *1 mass % 0 0 0 0 Other propylene-based polymer *2
mass % 86 86 86 96 Erucamide master batch *3 mass % 4 4 4 4 Resin
physical Total MFR g/10 min 47 39 33 31 properties Melting
endothermic amount .DELTA.H - D J/g 86 86 86 92 Extrusion molding
Molten resin temperature .degree. C. 200 200 200 200 condition
Extrusion amount/hole g/min/hole 0.4 0.4 0.4 0.4 Spinning Cooling
air temperature .degree. C. 12.5 12.5 12.5 12.5 condition Cooling
air speed m/sec 0.3 0.3 0.3 0.3 Ejector pressure kg/cm.sup.2 1.0
1.0 1.0 1.0 Line Calender temperature *4 .degree. C./.degree. C.
135/135 135/135 135/135 135/135 condition Nip pressure N/mm 40 40
40 40 Line speed m/min 119 119 119 119 Thread breakage time/min 0 0
0 Occurred frequently Physical Basis weight gsm 15.3 15.5 15.8 n.d.
*5 properties of Uniformity 2.9 3.9 4.7 n.d. *5 nonwoven fabric *1
Vistamaxx 6202; MFR 19 g/10 min *2 Propylene-based polymer (4):
NOVATEC SA03; MFR 30 g/10 min *3 Composition of erucamide master
batch: Y6005GM, 95 mass %, erucamide, 5 mass % *4 Left-side
value/right-side value = emboss roll temperature/S-roll temperature
*5 n.d. = Sampling was impossible swing to unstable spinning
(frequent thread breakage), and measurement was impossible.
[0233] From the results in Table 2, it is known that the spunbond
nonwoven fabric of Example 1 that had been produced using the
propylene-based resin composition containing the propylene-based
polymer as an olefin-based polymer having a melting endothermic
amount .DELTA.H-D of 38 J/g and MFR of 2,000 g/10 min, in which the
resin composition was melted and extruded at 200.degree. C., was
excellent in uniformity.
[0234] It is known that the uniformity of the spunbond nonwoven
fabrics of Comparative Examples 1 and 2 using the propylene-based
resin composition containing the propylene-based polymer having a
melting endothermic amount .DELTA.H-D of 35 J/g or 37 J/g and MFR
of less than 1,000 g/10 min was low.
[0235] In Comparative Example 3 where the propylene based resin
polymer having MFR of less than 1,000 g/10 min alone was used, the
spinning performance was unstable and thread breakage occurred
frequently, and therefore a spunbond nonwoven fabric could not be
obtained.
[0236] When the spunbond nonwoven fabric of Example 1 where the
propylene-based resin composition containing the propylene-based
polymer having MFR of 2,000 g/10 min as an olefin-based polymer was
used and the resin composition was melt-extruded and molded at
200.degree. C. was compared with the spunbond nonwoven fabric of
Reference Example 1 where the resin composition temperature was
changed to 240.degree. C., it is known that the formation
uniformity of the nonwoven fabric can be bettered by lowering the
molten resin temperature.
[0237] Further, is known that the formation uniformity of the
spunbond nonwoven fabrics of Comparative Examples 4 and 5, in which
the propylene-based resin composition containing the
propylene-ethylene copolymer having a melting endothermic amount
.DELTA.H-D of 19 J/g and MFR of less than 1,000 g/10 min was used
and the resin position was melted, extruded and molded at
240.degree. C., is also low.
Evaluation Method for Spunbond Nonwoven Fabric
Basis Weight
[0238] The weight of the resultant nonwoven fabric (5 cm.times.5
cm) was measured and the basis weight (g/m.sup.2 [also expressed as
gsm]) thereof was determined.
Formation Uniformity of Nonwoven Fabric
[0239] 16 sheets of specimens of 74 mm.times.53 mm were prepared
from the resultant nonwoven fabric. Subsequently, an image having
been converted into digital data was obtained using a scanner in a
state where a black drawing paper was superimposed on every
specimen. Each of the resultant image data was processed to a gray
scale (the degree of white and black was divided into 255 grades;
it means that as the value is large, the color is white), and from
the histogram, the mean value of gray scales and the standard
deviation of the gray scale values of the 16 sheets of specimens
were obtained.
[0240] An index that indicates the formation uniformity of the
nonwoven fabric was calculated from the mean value and the standard
deviation of the gray scale values according to the formula [1]. As
the value is small, the formation uniformity of the nonwoven fabric
is excellent.
[Formation uniformity of nonwoven fabric]=[mean value of gray
scales]/[standard deviation of gray scales] [1]
Production of Crimped Nonwoven Fabric
[0241] Next, Examples and Comparative Examples of crimped nonwoven
fabrics and multilayer nonwoven fabrics using the above-mentioned
materials and other materials are described. The components in
Table 3 and Table 4, which were used in preparing the first
component and the second component in Examples 3-1 to 3-5 and
Comparative Example 3-1 shown below, are as follows.
[0242] Propylene-based polymer (4): "NOVATEC-SA03" (trade name,
manufactured by Japan Polypropylene Corporation, MFR: 30 g/10 min,
melting point (Tm-D): 160.degree. C.)
[0243] Propylene-based polymer (5): "PP3155" (trade name,
manufactured by Exxon Mobil Chemical, MFR: 35 g/10 min)
[0244] Propylene-based polymer (6): "Prime Polypro.TM. S119" (trade
name, manufactured by Prime Polymer Co., Ltd., MFR: 60 g/10 min,
melting point (Tm-D): 166.degree. C.)
[0245] Propylene-based polymer (7): "Moplen HP461Y" (trade name,
manufactured by PolyMirae, MFR: 1,300 g/10 min, melting point
(Tm-D): 165.degree. C.)
[0246] Propylene-based polymer (8): "HG475" (trade name,
manufactured by Borealis AG, MFR: 27 g/10 min)
[0247] Propylene-based polymer (9): "HG455FB" (trade name,
manufactured by Borealis AG, MFR: 27 g/10 min, melting point
(Tm-D): 161.degree. C. (according to ISO 11357-3))
[0248] MFR of the above-mentioned propylene-based polymers (4) to
(9), and MFR of the olefin-based resin composition (I) of the first
component and the olefin-based resin composition (II) of the second
component in the following Table 3 and Table 4 were measured
according to the above-mentioned measurement method.
[0249] The melting endothermic amount .DELTA.H-D of the
olefin-based resin composition (I) of the first component in Table
3 and Table 4 was measured according to the above-mentioned
measurement method.
[0250] The melting point (Tm-D) was, unless otherwise specifically
indicated, measured according to the method mentioned below.
Melting Point (Tm-D)
[0251] Using a differential scanning calorimeter (manufactured by
Perkin Elmer Inc., trade name "DSC-7"), 10 mg of the sample as kept
at -10.degree. C. in a nitrogen atmosphere for 5 minutes and then
heated at 10.degree. C./min, and from the peak top at the peak
observed on the highest temperature side of the resultant melting
endothermic curve, the melting point Tm-D was determined.
Example 3-1
Preparation of First Component
[0252] 20% by mass of the propylene-based polymer (1) obtained in
Production Example 1, 78% by mass of the propylene-based polymer
(4), and 2% by mass of erucamide master batch prepared by mixing
90% by mass of "Prime Polypro.TM. S119" (trade name, manufactured
by Primer Polymer Co., Ltd., MFR: 60 g/10 min) and 10% by mass of
erucamide (2,000 ppm by mass, based on the olefin-based resin
composition (I), of erucamide was added) were mixed to prepare an
olefin-based resin composition (I).
Preparation of Second Component
[0253] 98% by mass of the propylene-based polymer (4), as the
propylene-based polymer (ii), and 2% by mass of an erucamide master
batch prepared by mixing 90% by mass of "Prime Polypro.TM. S119"
(trade name, manufactured by Primer Polymer Co., Ltd., MFR: 60 g/10
min) and 10% by mass of erucamide (2,000 ppm by mass, based on the
olefin-based resin composition (II), of erucamide was added) were
mixed to prepare an olefin-based resin composition (II).
Production of Side-by-Side Type Crimped Nonwoven Fabric
[0254] The first component and the second component were
independently melt-extruded at a resin temperature of 240.degree.
C., using separate single-screw extruders, and the molten resins
were ejected through a side-by-side type composite nozzle (number
of holes, 1,795 holes) having al nozzle diameter of 0.6 mm, at a
speed of 0.35 g/min/hole in such a manner that the ratio of the
first component to the second component could be 70/30, and thus
spun.
[0255] The fibers obtained through the spinning were, while cooled
with air at a temperature of 12.5.degree. C. and at a wind speed of
0.6 m/sec, suctioned with an ejector arranged at 1,400 mm below the
nozzle, under an ejector pressure of 2.0 kg/cm.sup.2, and were thus
deposited oar the net surface moving at a line speed of 53 m/min at
255 mm below the nozzle.
[0256] The fiber bundles deposited on the net surface were embossed
with an embossing roll heated at 50.degree. C., under a linear
pressure of 40 N/mm, and the crimped nonwoven fabric having a basis
weight of 20 g/m.sup.2 wound up with a take-up roll.
[0257] The resultant crimped nonwoven fabric was analyzed and
evaluated in the manner mentioned below. The results are shown in
Table 3.
Basis Weight
[0258] The basis weight was measured according to the
above-mentioned measurement method.
Fineness
Fineness Measurement
[0259] The fibers in the nonwoven fabric were observed under a
polarizing microscope, and the average [d (m)] of the diameters of
five randomly selected fibers was determined, and using the resin
density [.rho.=900,000 g/m.sup.3)], the fineness of the nonwoven
fabric sample was calculated according to the following formula
[2]:
fineness (denier)=.rho.
(g/m.sup.3).times..pi..times.(d(m)/2).sup.2.times.9,000 (m) [2]
Evaluation of Number of Crimps
[0260] The number of crimps was measured using an automated crimp
elastic modulus measuring device according to the measurement
method of a number of crimps as prescribed in HIS L1015:2000. One
fiber was extracted from a cotton-like sample before embossing in
such a manner that a tension was not applied to the fiber, the
length thereof when an initial load of 0.18 mN/tex was applied to
25 mm of the sample was measured, and the number of crimps at that
time was counted, thereby determining the number of crimps in the
length of 25 mm. It is meant that as the number of crimps is large,
the fiber-nonwoven fabric product is high in crimping
performance.
Evaluation of Bulkiness
[0261] Ten sheets of nonwoven fabric samples having a size of 5
cm.times.5 cm were superimposed, 1.9 g of a metal plate was placed
on the superimposed nonwoven fabric samples, and the thickness of
the superimposed nonwoven fabric samples was measured. It is meant
that as the numerical value of the thickness is high, the nonwoven
fabric is high in bulkiness.
Uniformity of Formation of Nonwoven Fabric
[0262] The formation uniformity was calculated and evaluated
according to the above-mentioned evaluation method.
Example 3-2
Preparation of First Component
[0263] An olefin-based resin composition (I) was prepared in the
same manner as that for the first component in Example 3-1 except
that the above-mentioned propylene-based polymer (5) was mixed in
place of the propylene-based polymer (4) in preparing the first
component in Example 3-1.
Preparation of Second Component
[0264] An olefin-based resin composition (II) was prepared in the
same manner as that for the second component in Example 3-1 except
that the above-mentioned propylene-based polymer (8) was mixed in
place of the propylene-based polymer (4) in preparing the second
component in Example 3-1.
Production of Side-by-Side Type Crimped Nonwoven Fabric
[0265] The formation of a nonwoven fabric was performed using a
spunbond machine (REICOFIL 4, manufactured by Reicofil GmbH). The
first component and the second component were spun in such a manner
that the components were independently melt extruded by separate
single-screw extruders at a resin temperature of 240.degree. C.,
and the molten resins were discharged through a side-by-side type
composite nozzle (number of holes: 1,795 holes) at a rate of 0.5
g/min per single hole in a mass ratio of the first component to the
second component of 70/30.
[0266] The fibers obtained by spinning were deposited at a
temperature of 30.degree. C. and a cabin pressure of 5,000 Pa on a
net surface moving at a line speed of 156 m/min. The fiber bundles
thus deposited on the net surface were embossed with an embossing
roll (embossing area ratio: 12%, engraved shape: circle) heated at
121.degree. C. and an S-roll heated at 127.degree. C. at a line
pressure of 50 N/mm, and the resultant crimped nonwoven fabric with
a basis weight of 20 g/m.sup.2 was wound up around a take-up
roll.
[0267] The resultant crimped non woven fabric was measured and
evaluated in the same manner as in Example 3-1. The results are
shown in Table 3.
Example 3-3
Preparation of First Component
[0268] 10% by mass of the propylene-based polymer (1) obtained in
Production Example 1, 88% by mass of the propylene-based polymer
(6), and 2% by mass of an erucamide master batch prepared by mixing
90% by mass of "Prime Polypro.TM. S119" (trade name, manufactured
by Primer Polymer Co., Ltd., MFR: 60 g/10 min) and 10% by mass of
erucamide (2,000 ppm by mass, based on the olefin-based resin
composition (I), of erucamide was added) were mixed to prepare an
olefin-based resin composition (I).
Preparation of Second Component
[0269] 98% by mass of the propylene-based polymer (8), as the
propylene-based polymer (ii), and 2% by mass of an erucamide master
batch prepared by mixing 90% by mass of "Prime Polypro.TM. S119"
(trade name, manufactured by Primer Polymer Co., Ltd., MFR: 60 g/10
min) and 10% by mass of erucamide (2,000 ppm by mass, based on the
olefin-based resin composition (II), of erucamide was added) were
mixed to prepare an olefin-based resin composition (II).
Production of Side-by-Side Type Crimped Nonwoven Fabric
[0270] A crimped nonwoven fabric was produced and evaluated in the
same manner as in the production method for the crimped nonwoven
fabric of Example 3-2, except that, in the production method for
the crimped nonwoven fabric in Example 3-2, the cabin pressure was
changed to 2,800 Pa and the line speed on the net surface was
changed to 140 m/min. The results are shown in Table 3.
Comparative Example 3-1
Preparation of First Component
[0271] 78% by mass of the propylene-based polymer (4), 20% by mass
of the propylene-based polymer (7) and 2% by mass of an erucamide
master batch prepared by mixing 90% by mass of "Prime Polypro.TM.
S119" (trade name, manufactured by Primer Polymer Co., Ltd., MFR:
60 g/10 min) and 10% by mass of erucamide (2,000 ppm by mass, based
on the olefin-based resin composition (I), of erucamide was added)
were mixed to prepare an olefin-based resin composition (I).
Preparation of Second Component
[0272] An olefin resin-based composition (II) was prepared in the
same manner as that of the preparation method for the second
component in Example 3-1.
Production of Side-by-Side Type Crimped Nonwoven Fabric
[0273] A crimped nonwoven fabric was produced in the same manner as
in the production method for the crimped nonwoven fabric of Example
3-1, and evaluated in the same manner. The results are shown in
Table 3.
TABLE-US-00003 TABLE 3 Unit Example 3-1 Example 3 Olefin-based
First Composition Propylene-based polymer (4) *1 Mass % 78 0 resin
component Propylene-based polymer (5) *2 Mass % 0 78 composition
Propylene-based polymer (6) *3 Mass % 0 0 Propylene-based polymer
(1) Mass % 20 20 Propylene-based polymer (7) *4 Mass % 0 0
Erucamide master batch *5 Mass % 2 2 Physical Total MFR g/10 min 71
81 properties Melting endothermic amount .DELTA.H - D J/g 76 80
Second Composition Propylene-based polymer (4) *1 Mass % 98 0
component Propylene-based polymer (8) *6 Mass % 0 98 Erucamide
master batch *5 Mass % 2 2 Physical Total MFR g/10 min 30 27
properties Fiber First component/second component Weight ratio
70/30 70/30 constitution Content of olefin-based polymer (1)
relative to whole fiber Mass % 14 14 Extrusion Molten resin
temperature .degree. C. 240 240 molding Extrusion amount per single
hole of first component g/min/hole 0.25 0.35 condition Extrusion
amount per single hole of second component g/min/hole 0.11 0.15
Spinning Cooling air temperature .degree. C. 12.5 30 condition
Cooling air speed m/sec 0.6 n.d.*8 Ejector pressure kg/cm.sup.2 2.0
n.d.*8 Cabin pressure Pa n.d.*8 5000 Line Calendaring temperature
*7 .degree. C./.degree. C. 50/50 121/12 condition Nip pressure N/mm
40 50 Line speed m/min 53 156 Thread breakage time/min 0 0 Physical
Basis weight gsm 20 20 properties Fineness denier 1.2 1.4 of
nonwoven Number of crimps number/25 mm 20 n.d.*8 fabric Bulkiness
mm 245 n.d.*8 Uniformity 3.6 2.3 *1 propylene-based polymer (4):
NOVATEC SA03; MFR 30 g/10 min *2 propylene-based polymer (5): PP
3155; MFR 35 g/10 min *3 propylene-based polymer (6): Prime Polypro
.TM. S119; MFR 60 g/10 min *4 propylene-based polymer (7): Moplen
HP461Y; MFR 1,300 g/10 min *5 composition of erucamide master
batch; Prime Polypro .TM. S119 = 90 mass %, erucamide = 10 mass %
*6 propylene-based polymer (8): HG475; MFR 27 g/10 min *7 left-side
value/right-side value = emboss roll temperature/S-roll temperature
*8n.d. = immesurable, or unmeasured. indicates data missing or
illegible when filed
Example 3-4
Preparation of First Component
[0274] 20% by mass of the propylene-based polymer (1) obtained in
Production Example 1, 78% by mass of the propylene-based polymer
(4), and 2% by mass of an erucamide master batch prepared by mixing
90% by mass of "Prime Polypro.TM. S119" (trade name, manufactured
by Primer Polymer Co., Ltd., MFR: 60 g/10 min) and 10% by mass of
erucamide (2,000 ppm by mass, based on the olefin-based resin
composition (I), of erucamide was added) were mixed to prepare an
olefin-based resin composition (I).
Preparation of Second Component
[0275] 100% by mass of the propylene-based polymer (4) was the
olefin-based resin composition (II).
Production of Side-by-Side Type Crimped Nonwoven Fabric
[0276] The first component and the second component were
independently melt-extruded at a resin temperature of 240.degree.
C., using separate single-screw extruders, and the molten resins
were ejected through a side-by-side type composite nozzle (number
of holes, 1,795 holes) having a nozzle diameter of 0.6 mm, at a
speed of 0.50 g/min/hole in such a manner that the ratio of the
first component to the second component could be 70/30, and thus
spun.
[0277] The fibers obtained through the spinning were, while cooled
with air at a temperature of 12.5.degree. C. and at a wind speed of
0.6 m/sec, suctioned with an ejector arranged at 1,400 mm below the
nozzle, under an ejector pressure of 1.5 kg/cm.sup.2, and were thus
deposited on the net surface moving at a line speed of 75 m/min at
255 mm below the nozzle.
[0278] The fiber bundles deposited on the net surface were embossed
with an embossing roll heated at 70.degree. C. under a linear
pressure of 40 N/mm, and the crimped nonwoven fabric having a basis
weight of 15 g/m.sup.2 wound up with a take-up roll.
Production of Melt-Blown Nonwoven Fabric
[0279] A melt-blown nonwoven fabric apparatus including a
single-screw extruder, a die (nozzle, hole diameter: .PHI.0.15 mm,
number of holes: 720), a high-temperature compressed air generator,
a net conveyer, and a winder was used. The polypropylene polymer
(7) was melted at a resin temperature of 260.degree. C., and the
molted resin was ejected through the die at a speed of 0.1
g/min/single hole. The resin was deposited on a net conveyor
surface moving at a line speed of 24 m/min at a flow rate of 360
Nm.sup.3/hr, using compressed air at 270.degree. C., and the
resultant melt-blown nonwoven fabric having a basis weight of 5
g/m.sup.2 was wound with the winder.
Production of Multilayer Nonwoven Fabric
[0280] The crimped nonwoven fabric and the melt-blown nonwoven
fabric were layered and the layered nonwoven fabrics were embossed
with an embossing, roll (embossing area ratio: 16%, engraved shape:
diamond shape) heated at 70.degree. C. under a linear pressure of
40 N/mm, and the resultant multilayer nonwoven fabric having a
basis weight of 20 g/m.sup.2 was wound with a winder.
[0281] The basis weight of each of the resultant crimped nonwoven
fabric, melt-blown nonwoven fabric and multilayer nonwoven fabric
was measured according to the above-mentioned measurement method.
In addition, regarding the multilayer nonwoven fabric, the
formation uniformity of the nonwoven fabric was determined and
evaluated according to the above-mentioned evaluation method. The
results are shown in Table 4.
Example 3-5
Preparation of First Component
[0282] 40% by mass of the propylene-based polymer (1) obtained in
Production Example 1, 56% by mass of the propylene-based polymer
(5), and 4% by mass of an erucamide master batch prepared by mixing
95% by mass of "Y6005GM" (trade name, manufactured by Primer
Polymer Co., Ltd., MFR: 60 g/10 mm) and 5% by mass of erucamide
(2,000 ppm by mass, based on the olefin-based resin composition
(I), of erucamide was added) were mixed to prepare an olefin-based
resin composition (I).
Preparation of Second Component
[0283] 96% by mass of the propylene-based polymer (9), as the
propylene-based polymer (ii), and 4% by mass of an erucamide master
batch prepared by mixing 95% by mass of "Y6005GM" (trade name,
manufactured by Primer Polymer Co., Ltd., MFR: 60 g/10 min) and 5%
by mass of erucamide (2,000 ppm by mass, based on the olefin-based
resin composition (II), of erucamide was added) were mixed to
prepare an olefin-based resin composition (II).
Production by Side-by-Side Type Crimped Nonwoven Fabric
[0284] The formation of a nonwoven fabric was performed using a
spunbond machine (REICOFIL 4, manufactured by Reicofil GmbH). The
first component and the second component were spun in such a manner
that the components were independently melt extruded by separate
single-screw extruders at a resin temperature of 250.degree. C.,
and the molten resins discharged through a side-by-side type
composite nozzle (number of holes: 1,795 holes) at a rate of 0.50
g/min per single hole in a ratio of the first component to the
second component of 70/30.
[0285] The fibers obtained by spinning were deposited at a
temperature of 20.degree. C. and a cabin pressure of 3,000 Pa on a
net surface moving at a line speed of 167 m/min. The fiber bundles
thus deposited on the net surface were embossed with an embossing
roll (embossing area ratio: 12%, engraved shape: circle) heated at
115.degree. C. and an S-roll heated at 113.degree. C. at a line
pressure of 50 N/mm, and the resultant crimped nonwoven fabric with
a basis weight of 15 g/m.sup.2 was wound up around a take-up
roll.
Production of Melt-Blown Nonwoven Fabric
[0286] Produced according to the same method as in Example 3-4.
Production of Multilayer Nonwoven Fabric
[0287] Produced according to the same method, as in Example
3-4.
[0288] The basis weight of each of the resultant crimped nonwoven
fabric, melt-blown nonwoven fabric and multilayer nonwoven fabric
was measured according to the above-mentioned measurement method.
In addition, regarding the multilayer nonwoven fabric, the
formation uniformity of the nonwoven fabric was determined and
evaluated according to the above-mentioned evaluation method. The
results are shown in Table 4.
TABLE-US-00004 TABLE 4 Unit Layered Crimped First Composition
Propylene-based polymer (4) *1 Mass % nonwoven nonwoven component
Propylene-based polymer (5) *2 Mass % fabric fabric Propylene-based
polymer (1) Mass % (crimped Erucamide master batch *3 Mass %
nonwoven Physical Total MFR g/10 min fabric/ properties Melting
endothermic amount .DELTA.H - D J/g melt-blown Second Composition
Propylene-based polymer (4) *1 Mass % nonwoven component
Propylene-based polymer (9) *4 Mass % fabric) Erucamide master
batch *3 Mass % Physical Total MFR g/10 min properties First
component/second component Weight ratio Content of propylene-based
polymer (1) relative to whole fibers Mass % Molten resin
temperature .degree. C. Single hole ejection amount (first
component) g/min/hole Single hole ejection amount (second
component) g/min/hole Cooling air temperature .degree. C. Cooling
air speed m/sec Ejector pressure kg/cm.sup.2 Cabin pressure Pa
Calendering temperature *5 .degree. C./.degree. C. Nip pressure
N/mm Line speed m/min Layering Layering method -- condition
Calendering temperature *5 .degree. C./.degree. C. Nip pressure
N/mm Properties of Basis weight (gsm) Whole weight multilayer
Crimped nonwoven fabric nonwoven Melt-blown nonwoven fabric fabric
Uniformity *1 propylene-based polymer (4): NOVATEC SA03; MFR 30
g/10 min *2 propylene-based polymer (5): PP 3155; MFR 35 g/10 min
*3 composition of erucamide master batch At 2 mass % addition:
Prime PolyproTSM119 = 90 mass %, erucamide = 10 mass % At 4 mass %
addition: Y6005GM = 95 mass %, erucamide = 5 mass % *4
propylene-based polymer (9): HG455FB; MFR 27 g/10 min *5 left-side
value/right-side value = emboss roll temperature/S-roll temperature
*6 n.d. = immeasurable, or unmeasured. indicates data missing or
illegible when filed
INDUSTRIAL APPLICABILITY
[0289] The spunbond nonwoven fabric of the first aspect of the
invention, the spunbond nonwoven fabric of the second aspect of the
invention and the nonwoven fabric formed of composite fibers of the
third aspect of the invention each are independently excellent in
formation uniformity, and are therefore favorably used for various
fiber products such as disposable diapers, sanitary products,
hygienic products, clothing materials, bandages, packing materials,
etc.
[0290] In addition, according to the production method for spunbond
nonwoven fabrics of the second aspect of the invention, a spunbond
nonwoven fabric having uniform texture and excellent in feeling can
be obtained with maintaining stable melt moldability and
spinnability.
[0291] Further, in the case where the nonwoven fabric formed of
composite fibers of the third aspect of the invention is a nonwoven
fabric formed of crimped fibers, the nonwoven fabric is formed of
fibers having strong crimping performance using a polyolefin
material without post treatment such as stretching or heating, and
the nonwoven fabric is bulky and have good feeling, and is
therefore useful for production of fibers and wipers.
* * * * *