NONWOVEN FABRIC
Technical Field
[0001]
The present invention relates to a nonwoven fabric
comprising an embossed portion and a non-embossed portion.
Background Art
[0002]
Nonwoven fabrics, typified by spunbond nonwoven fabrics,
10 are usually partially thermocompressed (emboss-treated) via an
embossing roll in order to prevent the falling-off of fibers which
form the nonwoven fabrics.
[0003]
Emboss patterns (emboss shapes) formed by the
15 thermocompression are usually formed regularly with a
predetermined interval in the machine direction (Machine
Direction: hereinafter, also referred to as MD) of the nonwoven
fabric and in the direction. crossing the machine direction (Cross
Machine Direction: hereinafter, also referred to as CD).
20 [0004]
The emboss patterns considerably affect the properties of
the resultant nonwoven fabric such as strength, elongation,
softness, resistance to falling-off of fibers and fuzz, and thus
various emboss patterns have been proposed.
SF--2350 2
[0005]
For example, Patent Literature 1 (JP-A-S57-167442) proposes
a nonwoven fabric having an emboss pattern with unit patterns each
being in the shape of rhombus or hexagon, wherein the emboss line
5 of the unit pattern is formed by arranging a plurality of shapes
such as square point, circular point, line and dotted line, with
a predetermined interval.
[0006]
Patent Literature 2 (JP-A°-H11-335960) proposes a nonwoven
10 fabric having an emboss pattern with unit patterns each being in
the shape of lattice, wave, line, ellipse or arc, wherein the
emboss line of the unit pattern is a straight line.
Citation List
15 Patent Literatures
[0007]
[Patent Literature 1] JP-A-S57-167442
[Patent Literature 2] JP-A-Hll-335960
20 Summary of Invention
Technical Problem
[0008]
However, among these emboss patterns, for example, as shown
in Fig. 7, a nonwoven fabric with a rhombus unit pattern 118 which
SF-2350 3
is formed from emboss lines 116 each formed from square points
120, has a problem that fibers markedly lift between a non-embossed
portion 114 and a non-embossed portion 114 that are adjacent to
each other via the emboss line 116, and tends to be inferior in
fuzz resistance.
[0009]
On the other hand, as shown in Fig. 8, the nonwoven fabric
with an emboss pattern delimited in the shape of a lattice (a unit
pattern 218 is in the shape of square rhombus) wherein each emboss
10 line 216 is continuous by being a straight line 220, is excellent
in fuzz resistance but has a problem that it is inferior in
softness.
[0010]
With such emboss lines in the unit patterns of the embossed
15 portions as proposed in the above Patent Literatures and the like,
it is possible to cause a change in fuzz resistance, softness or
tensile strength of the resultant nonwoven fabric, but it is
difficult to achieve excellent balance among fuzz resistance,
softness and tensile strength in the resultant nonwoven fabric.
20 [0011]
The present invention has been made in view of such current
circumstances. It is an object of the present invention to
provide a nonwoven fabric excellent in the balance among fuzz
resistance, softness and tensile strength.
Solution to Problem
[0012]
The present invention has been made to overcome the problems
5 in conventional technique as described above.
The nonwoven fabric of the present invention is directed
to a nonwoven fabric comprising an embossed portion and a
non-embossed portion,
the embossed portion comprising an emboss pattern that
10 comprises unit patterns each delimited by emboss lines,
the emboss lines each comprising a plurality of emboss
element parts that are continuously arranged with a predetermined
interval,
wherein in the direction in which the distance from an
15 arbitrarily-defined point in the non-embossed portion within the
unit pattern toward the outside of the emboss lines that delimit,
the non-embossed portion is shortest, at least one of the plurality
of emboss element parts is disposed so as to block the direction
in which the distance from the arbitrarily-defined point toward
20 the outside of the emboss lines that delimit the non-embossed
portion is shortest.
[0013]
With the nonwoven fabric having such a structure, i e e. , the
emboss element parts are provided by partial thermocompression
SF-2350 5
and the non-embossed portion is surrounded by the non-continuous
embossed portion, fibers do not markedly lift between non-embossed
portions that are adjacent to each other via the emboss line, and
thereby excellent fuzz resistance is achieved.
[0014]
Furthermore, such a nonwoven fabric, in which the
non-embossed portion is present having some degree of size and
the emboss line is non-continuous, is superior in softness to a
nonwoven fabric having an emboss pattern formed by a continuous
10 emboss line.
[0015]
In addition, such a nonwoven fabric has a tensile strength
equivalent to that of a conventional nonwoven fabric, and
accordingly it is excellent in the balance among fuzz resistance,
15 softness and tensile strength.
[0016]
In the nonwoven fabric of the present invention, the emboss
line is formed by disposing the plurality of emboss element parts
with an equal interval from each other so as to form dotted lines.
20 [0017]
Such a nonwoven fabric, by having an emboss line that is
dotted lines, is at a state of being partially thermocompressed,
and thus prevents fibers from markedly lifting between
non-embossed portions that are adjacent to each other via the
SF-2350 6
emboss line, and thus is excellent in fuzz resistance.
[0018]
In the nonwoven fabric of the present invention, the emboss
line is formed by continuously disposing the plurality of emboss
element parts, each of which is inclined, with an equal interval
from each other.
[0019]
Such a nonwoven fabric, by having an emboss line formed from
the plurality of inclined emboss element parts, is at a state of
10 being partially thermocompressed, and thus prevents fibers from
markedly lifting between non-embossed portions that are adjacent
to each other via the emboss line, and thus is excellent in fuzz
resistance.
[0020]
15 In the nonwoven fabric of the present invention, the length
of the emboss element part is 0. 5 to 5 mm, and the interval between
the emboss element parts that are disposed so as to form dotted
lines is 0.5 to 5 mm.
[0021]
20 Such a nonwoven fabric, by having emboss element parts as
described above, prevents fibers from markedly lifting between
non-embossed portions that are adjacent to each other via the
emboss line, and thus excellent in fuzz resistance.
[0022]
SL'-2350 7
In the nonwoven fabric of the present invention, the shape
of the emboss element part is any of a straight line, a curved
line and a zigzag shape.
[00231
Such a nonwoven fabric, by having an emboss element part
shaped as described above, prevents fibers from markedly lifting
between non-embossed portions that are adjacent to each other via
the emboss line, and thus is excellent in fuzz resistance.
[0024]
10 In the nonwoven fabric of the present invention, the unit
patterns each delimited by the emboss lines are regularly disposed
in the machine direction (Machine Direction) of the nonwoven
fabric and in the direction crossing machine direction (Cross
Machine Direction).
15 [0025]
Such a nonwoven fabric, by having unit patterns disposed
regularly, prevents fibers from markedly lifting in any part of
the nonwoven fabric, and thus is preferable.
[0026]
20 In the'nonwoven fabric of the present invention, the unit
pattern has a length of the width in the machine direction (Machine
Direction) of the nonwoven fabric of 2 to 15 mm, and a length of
the width in the direction crossing the machine direction (Cross
Machine Direction) of 2 to 15 mm.
ST-2350 8
[0027]
Such a nonwoven fabric, by having a unit pattern with lengths
as described above, surely prevents fibers from markedly lifting
between non-embossed portions that are adjacent to each other via
the emboss line.
[0028]
Such a nonwoven fabric, by having a unit pattern with a size
as described above, is excellent in softness, too.
[0029]
10 In the nonwoven fabric of the present invention, the line
width of the emboss line is Oe5 to 3 mm.
[0030]
Such a nonwoven fabric, by having an emboss line with a line
width as described above, is excellent in the balance among fuzz
15 resistance, softness and tensile strength.
[0031]
In the nonwoven fabric of the present invention, the unit
pattern delimited by the emboss lines is in the shape of rhombus.
[0032]
20 Such a nonwoven fabric, by having a rhombus unit pattern,
is excellent particularly in the balance among fuzz resistance,
softness and tensile. strength.
[0033]
The resultant emboss pattern of the present invention, in
SF--2350 9
which the embossed portion looks sewn, can provide high-quality
appearance as seen in woven fabrics, in spite of being the emboss
pattern of nonwoven fabrics, and thus the nonwoven fabric of the
present invention is also excellent from aesthetic viewpoint.
Advantageous Effect of Invention
[0034]
According to the present invention, the emboss element parts,
which form the emboss lines that delimit the unit pattern, are
10 provided by partial thermocompression, and the non-embossed
portion is surrounded by the non-continuous embossed portion. As
a result, fibers do not markedly lift between non-embossed
portions adjacent to each other via the emboss line, leading to
the nonwoven fabric excellent in fuzz resistance. Moreover, the
15 non-embossed portion is present having some degree of size and
the emboss line is non-continuous. As a result, the nonwoven
fabric is excellent in softness, too. Furthermore, the tensile
strength is equivalent to that of a conventional nonwoven fabric.
Accordingly, the nonwoven fabric is excellent in the balance among
20 fuzz resistance, softness and tensile strength.
Brief Description of Drawings
[0035]
[Fig. 1] Fig. 1 is a front view of a nonwoven fabric comprising
SF--2350 10
an embossed portion and a non-embossed portion in an embodiment
of the present invention.
[Fig. 2] Fig. 2 is an enlarged view focusing on a unit pattern
portion of an embossed portion of the nonwoven fabric shown in
5 Fig. 1.
[Fig. 3] Fig. 3 illustrates how emboss element parts are disposed.
[Fig. 4] Fig. 4 illustrates other embodiments of emboss element
parts. Fig. 4(a) illustrates curved emboss element parts, and
Fig. 4(b) illustrates zigzag emboss element parts.
10 [Fig. 5] Fig. 5 is an enlarged view focusing on another unit pattern
portion in an embossed portion.
[Fig. 6] Fig. 6 illustrates other embodiments of a unit pattern.
Fig. 6(a) illustrates a triangle unit pattern; Fig. 6(b)
illustrates a rectangle unit pattern; Fig. 6(c) illustrates a
15 circle unit pattern; and Fig. (d) illustrates a testudinarian unit
pattern.
[Fig. 7] Fig. 7 illustrates the structure of an emboss line of
a conventional nonwoven fabric.
[Fig. 8] Fig. 8 illustrates the structure of an emboss line of
20 a conventional nonwoven fabric.
Embodiments of Description
[0036]

SF-2350 11
A fiber which forms the nonwoven fabric according to the
present invention is not particularly limited, and is selected
from natural fibers such as cellulose, regenerated fibers such
as rayon, synthetic fibers composed of thermoplastic polymers,
and the like. Of these fibers, synthetic fibers are preferable,
which are suited for the production of nonwoven fabrics.
[0037]
The thermoplastic polymers serving as raw materials of the
synthetic fibers are not particularly limited as long as being
10 capable of being formed into fibers to produce nonwoven fabrics.
[0038]
Specific examples thereof include polyolefins such as
polyethylene and polypropylene, polyolefin elastomers,
polystyrene polymers, polystyrene elastomers, polyesters,
15 polyester elastomers, polyamides, polyamide elastomers,
polyurethanes and polylactic acids. As the thermoplastic polymer,
a combination of two or more kinds of these polymers, or a
composition containing two or more kinds of these polymers may
be used.
20 [0039]
Of the thermoplastic polymers, polyolefins such as
polyethylene and polypropylene are preferable. Polypropylene is
preferable, which achieves excellent spinning stability during
molding operation and processability of nonwoven fabrics, and
SF-2350 12
provides a nonwoven fabric excellent in breathability, softness,
lightness and heat resistance.
[0040]
Examples of the polypropylene include propylene
5 homopolymers and copolymers of propylene with a small amount of
one or more kinds of a-olefins having 2 or more carbon atoms
(excluding an a-olefin having 3 carbon atoms), preferably
a-olefins having 2 to 8 carbon atoms (excluding an a-olefin having
3 carbon atoms) , such as ethylene, 1-butene, 1-pentene, 1-hexene,
10 1-octene and 4-methyl-l-pentene, the homopolymers and the
copolymers having a melting point (Tm) of 125°C or higher,
preferably 130 to 165°C.
[0041]
The thermoplastic polymers may optionally contain
15 commonly-used additives in a range which is not detrimental to
the object of the present invention, such as antioxidants,
weathering stabilizers, light stabilizers, anti-blocking agents,
lubricants, nucleating agents, pigments, hydrophilizing agents,
water repellents and assistants.
20 [0042]

The nonwoven fabric according to the present invention is
not particularly limited. Examples thereof include various known
nonwoven fabrics such as a spunbond nonwoven fabric, a meltblown
SF'-2350 13
nonwoven fabric, a wet-type nonwoven fabric, a dry-type nonwoven
fabric, a dry-type pulp nonwoven fabric, a flash spinning nonwoven
fabric and an open nonwoven fabric.
[0043]
5 Of these nonwoven fabrics, a spunbond nonwoven fabric is
preferable, since it is formed from long fibers and can be
efficiently treated through a continuous step from spinning to
emboss treatment, and it can be readily formed into a composite
with another nonwoven fabric such as a meltblown nonwoven fabric.
10 [0044]
The fiber which forms the nonwoven fabric according to the
present invention usually has a fineness of 0.5 to 5 denier,
preferably 0.5 to 3 denier. The fiber which forms the nonwoven
fabric may be a short fiber, but is preferably a long fiber, for
15 reasons that, eege, in the case of long fibers, the fibers do not
fall off from the resultant nonwoven fabric.
[0045]
The fiber which forms the nonwoven fabric, when being a
synthetic fiber, may be a fiber of a single kind of thermoplastic
20 polymer selected from those described above; or a composite fiber
having a core-sheath structure, a side-by-side structure or the
like formed from two or more kinds of thermoplastic polymers
selected from those described above.
[0046]
SF-2350 14
The fiber may have a shape such that its cross-sectional
shape is circle or an irregular one such as V-shape,
crisscross-shape and T-shape; or may be a crimped fiber. In
particular, a crimped fiber is preferable, which can provide the
resultant nonwoven fabric with more improved softness, bulkiness
and stretchability.
[0047]
The nonwoven fabric according to the present invention
usually has a basis weight of 3 to 100 g/m2, preferably '7 to 60
10 g/m2
[0048]

As shown in Fig. 1, the nonwoven fabric 10 of the present
invention is a nonwoven fabric 10 comprising an embossed portion
15 (thermocompressed portion) 12 and a non-embossed portion
(non-compressed portion) 14.
[0049]
In the specification of the present invention, the embossed
portion 12 refers to a portion formed by partially
20 thermocompressing a nonwoven fabric with an embossing roll (not
shown in the drawing), while the non-embossed portion 14 refers
to the other portion that has not been thermocompressed. Thus,
the embossed portion and the non-embossed portion are not formed
to provide particular separated regions.
SF--2350 15
[0050]
The embossed portion 12 is formed from an emboss pattern
formed by repeating an emboss pattern 18 delimited by emboss lines
16, In an embodiment of the present invention, as shown in Fig.
1 and Fig. 2, the unit pattern 18 is in the shape of rhombus.
[0051]
The line width Wl of the emboss line 16 is preferably 0.5
to 3 mm.
[0052]
10 The line width Wl of less than 0.5 mm, which makes the
embossed portion (thermocompressed portion) 12 extremely small,
may result in the nonwoven fabric 10 being excellent in softness
but being insufficient to suppress fuzz.
[0053]
15 On the other hand, the line width W1 of more than 3 mm, which
increases the interval between the embossed portion
(thermocompressed portion) 12 and the embossed portion
(thermocompressed portion) 12 and enlarges the non-embossed
portion 14, reduces fuzz-preventing effect and may cause fibers
20 to markedly lift through the non-embossed portion 14. In addition,
the tensile strength may be reduced. Thus, such a line width is
not preferred.
[0054]
As shown in Fig. 2, the emboss line 16 is formed by
SF-2350 16
continuously arranging a plurality of emboss element parts 20 with
a predetermined interval.
[00551
In a point where the emboss line 16 and the emboss line 16
5 intersect one another, too, each emboss element part 20 does not
overlap one another, i.e., each emboss element part 20 are spaced
from one another.
[0056]
As shown in Fig. 3, in the direction in which the distance
10 from an arbitrarily-defined point 22 in the non-embossed portion
14 within a unit pattern 18 toward the outside of the emboss lines
16 that delimit the non-embossed portion 14 is shortest, i.e.,
an arrow 24, a plurality of emboss element parts 20 are formed
so as to overlap one another, and the emboss element parts 20 are
15 disposed so as to block this direction.
[0057]
In an embodiment of the present invention, the emboss
element parts 20 are disposed so as to form two dotted lines, and
the non-embossed portion 14 (a portion between the emboss element
20 part 20 and the emboss element part 20) on the dotted line does
not overlap the non-embossed portion 14 on the adjacent dotted
line.
[0058]
In Fig. 3, the emboss element parts 20 are disposed so as
-2350 17
to form two dotted lines, but the number of lines is not
particularly limited. More than two lines may be provided as long
as the non-embossed portion 14 on the dotted line does not overlap
the non-embossed portion 14 on the adjacent dotted line.
[0059]
The shape of each emboss element part 20, which is a straight
line in the above embodiment, is not particularly limited, and
may be, for example, a curved line as shown in Fig. 4(a), or a
zigzag shape as shown in Fig. 4(b).
10 [0060]
As shown in Fig. 2, the length W2 of the emboss element part
20 is preferably 0>5 to 5 mm.
[0061]
The length W2 of less than 0,5 mm leads to the difficulty
15 in disposing the emboss element part 20 and makes the embossed
portion (thermocompressed portion) 12 itself smaller. This may
result in the failure to prevent fuzz, and may lead to inferior
durability of an embossing roll, which may be an obstacle to
productiv
20 [0062]
Y_
On the other hand, the length W2 of more than 5 mm enlarges
a continuous part of the embossed portion (thermocompressed
portion) 12. This may reduce the softness of the resultant
nonwoven fabric 10.
SF--2350 18
[0063]
The interval W3 between the emboss element part 20 and the
emboss element part 20 (distance of non-embossed portion 14) is
preferably 0.5 to 5 mm.
[0064]
The interval W3 of less than 0,5 mm makes the embossed
portion (thermocompressed portion) 12 substantially continuous.
This may reduce the softness of the resultant nonwoven fabric 10,
[0065]
10 On the other hand, the interval W3 of more than 5 nun increases
the interval between the embossed portion (thermocompressed
portion) 12 and the embossed portion (thermocompressed portion)
12 and enlarges the non-embossed portion. This reduces
fuzz-preventing effect and may cause fibers from markedly lifting
15 through the non-embossed portion. In addition, the tensile
strength may be reduced. Thus, such an interval is not preferred.
[0066]
The thickness W4 of the emboss element part 20 is preferably
0.05 to 1,5 mm, more preferably 0.1 to 1.0 mm.
20 [0067]
The thickness W4 of less than 0.05 mm may lead to the
difficulty in processing an embossing roll itself for forming the
emboss element parts 20 on the nonwoven fabric.
[0068]
SF-2350 19
On the other hand, if the thickness W4 is more than 1.5 mm,
the emboss line 16 is so thick that the softness may be reduced.
[0069]
The unit pattern 18 delimited by such emboss lines 16 has
5 a length W5 of the width in the machine direction (MD) of the
nonwoven fabric 10, and a length W6 of the width in the direction
crossing the machine direction (CD) each preferably being 2 to
15 mm, more preferably 3 to 10 mm.
[0070]
10 If the lengths W5 and W6 are each less than 2 mm, the resultant
nonwoven fabric 10 tends to be excellent in fuzz resistance but
inferior in softness.
[0071]
On the other hand, if the lengths W5 and W6 are each more
15 than 15 mm, the resultant nonwoven fabric 10 tends to be excellent
in softness but cause fibers to markedly lift within the unit
pattern 18 and tends to be inferior in fuzz resistance.
Furthermore, the tensile strength may be reduced.
[0072]
20 The length W5 of the width in the machine direction (MD)
of the fabric and the length W6 of the width in the direction
crossing the machine direction (CD) may be the same as or different
from each other.
[0073]
SF--2350 20
When the unit pattern 18 is in the shape of rhombus as in
an embodiment of the present invention, the length of each side
forming the rhombus is preferably 3 to 10 mm.
[0074]
5 Thus, as in the embodiment of the present invention shown
in Fig. 3, where the unit pattern 18 is in the shape of rhombus,
each side forming the rhombus can include about 3 to 10 emboss
element parts 20 in view of suitability of emboss roll processing.
[0075]
10 In an embodiment of the present invention, the emboss
element parts 20 are disposed with an equal interval from each
other so as to form dotted lines. In another embodiment, as shown
in Fig. 5, the emboss element parts 20 each of which is inclined
may be continuously disposed with an equal interval from each
15 other.
[0076]
As described above, in the nonwoven fabric of the present
invention 10, the emboss line 16 is formed by continuously
arranging a plurality of emboss element parts 20 with a
20 predetermined interval; and in the direction in which the distance
from an arbitrarily-defined point 22 in the non--embossed portion
14 within the unit pattern 18 toward the outside of the emboss
lines 16 that delimit the non-embossed portion 14 is shortest,
iae,, arrow 24, a plurality of emboss element parts 20 are formed
SF-2350 21
so as to overlap one another, and the emboss element parts 20 are
disposed so as to block the direction in which the distance is
shortest, i.e., arrow 24.
[0077]
Such a structure achieves superior balance among fuzz
resistance, softness and tensile strength, as compared with a
conventional embodiment in which emboss lines delimiting a unit
pattern are formed by continuously disposing square points or are
straight lines.
10 [0078]
The nonwoven fabric 10 of the present invention overcomes
the problem that fibers markedly lift between the unit patterns
adjacent to each other via the non-embossed portion, which problem
has been seen particularly in conventional embodiments in which
15 the emboss line is a dotted line, and therefore is excellent in
fuzz resistance.
[0079]
The nonwoven fabric 10 of the present invention also. has
a tensile strength equivalent to that of a conventional fabric,
20 and accordingly is excellent in the balance among fuzz resistance,
softness and tensile strength.
[0080]
No nonwoven fabric has been provided which is excellent
particularly in the balance among fuzz resistance and softness,
SF-2350 22
and thus the nonwoven fabric of the present invention can be
suitably used for sanitary materials, particularly for materials
of disposable diapers.
[0081]
5 Specifically, in the application to a back sheet of the
disposable diaper, while the fuzz is suppressed, the softness can
be significantly improved, as compared with a conventional
nonwoven fabric. In this application, the use of a crimped fiber
as a fiber which forms the nonwoven fabric can further improve
10 the softness.
[0082]
Superiority in softness of the nonwoven fabric of the
present invention suggests its excellent feel and its easy
secondary processability,
15 [0083]
For example, even when subjected to ring roll processing,
gear stretch processing, shape-processing, pleat processing or
the like, the nonwoven fabric is not ruptured and has a high degree
of freedom about its deformation. The use of a crimped fiber as
20 a fiber which forms the nonwoven fabric imparts the stretchability
of the crimped fiber to the nonwoven fabric, which results in
having higher degree of freedom about its processability. In some
cases, the nonwoven fabric is employable also as part of a
stretchable material.
SF-2350 23
[0084]
On the other hand, when a raw material has a hydrophilizing
agent kneaded thereto or is coated with a hydrophilizing agent,
the nonwoven fabric of the present invention is suitably
employable as a top sheet of a disposable diaper.
[0085]
Since the top sheet is a material contacting with skin, its
softness is prioritized. The emboss pattern of the nonwoven
fabric of the present invention provides excellent softness, and
10 thus is suitable.
[0086]
The use of a crimped fiber as a fiber can further improve
softness felt by skin. In addition to the softness felt by skin,
significant issues with regard to the top sheet include whether
15 the top sheet can prevent a liquid from returning from an absorber.
[0087]
To overcome the liquid-returning problem, it is known to
thicken a nonwoven fabric to thereby prevent the liquid-returning.
The nonwoven fabric of the present invention is easy to thicken,
20 because in the nonwoven fabric, the non-embossed portion is
present having some degree of size. The use of a crimped fiber
as a fiber which forms the nonwoven fabric can further thicken
the nonwoven fabric.
[0088]
SF-2350 24
Hereinabove, preferable embodiments of the present
invention are described, but the present invention is not limited
to the above embodiments. For example, in the embodiment
described above, the shape of the unit pattern 18 of the embossed
5 portion 12 is rhombus, but the present invention is not limited
thereto. As shown in Fig. 6, exemplary shapes include triangle
shape (Fig. 6(a)), rectangle shape (Fig. 6(b)), polygonal shape,
circular shape (Fig. 6(c)), star shape, testudinarian shape (Fig.
6(d)) and character design shape. That is, any shape is
10 employable as long as having a closed shape and being capable of
providing a repeating structure. The shape may be modified in
various ways in a range that does not deviate from the object of
the present invention.
15 Examples
[0089]

In accordance with JIS-L1096-1990, 6.4.2, "mass per unit
20 area under standard conditions", the basis weight was measured.
From a nonwoven fabric sample prepared, a circular test piece of
100 cm2 was collected.
[0090]
The samples were collected at a place that was arbitrari
SF-2350 25
determined in the machine direction (MD) and were collected at
20 points with a uniform interval that would form a straight line
in the direction crossing the machine direction (CD) The samples
were not collected at a place between each end and 20 cm inward
from each end of the nonwoven fabric sample in the direction
crossing the machine direction (CD).
[0091]
Using pan electronic balance (EB-330 manufactured by
Shimadzu Corporation), a mass (g) of each test piece collected
10 was measured. Then, an average mass (g) of the test pieces was
calculated.
[0092]
The average mass calculated was converted to a mass (g) per
1 m2, and rounded to one decimal place to provide a basis weight
15 (g/m2) of each nonwoven fabric sample.
[0093]
(1) Evaluation of fuzz resistance
From the nonwoven fabric sample prepared, 40 test pieces
each having a size of 300 mm (MD) x 25 mm (CD) were collected,
20 and the fuzz resistance was evaluated using an apparatus, "rubbing
tester II (Gakushin-type) " described in JIS-L0849--2004, 5, 501,
b.
[0094]
Specifically, as such an apparatus, RT-100 manufactured by
SF-2350 26
DAIEI KAGAKU SEIKI MFG, Co,, Ltd, was employed. A 200 g friction
block was used. A packing adhesive tape (cloth) No. 314
(manufactured by Rinrei Tape Co., Ltd.) was placed such that the
adhesive surface of the adhesive tape would rub the testing surface
of the test piece.
[0095]
To prevent the test piece from moving during the test,
sandpaper (No. 400) was fitted to a table of the apparatus with
the abrasive surface upward. The test piece was placed on the
10 abrasive surface and was fitted to the tester table with the
testing surface upward.
[0096]
After the fitting of he test piece, the testing surface
of the test piece and the non--adhesive surface of the adhesive
15 tape were rubbed against each other back and forth 50 times. The
rubbed testing surface of the test piece was observed, and the
fuzz resistance was graded based on the following criteria.
[0097]
1 point: There was no fuzz.
20 [0098]
2 points: A small fuzzball started to form.
[0099]
3 points: A recognizable fuzzball started to form, and a plurality
of small fuzzballs formed.
SF--2350 27
[0100]
4 points: Recognizable large fuzzballs formed, and a plurality
of fibers started to lift.
[0101]
5 5 points: Fibers were considerably torn off and the test piece
became thin.
[0102]
6 points: Fibers were torn off and the test piece was broken.
[0103]
10 (2) Evaluation of tensile strength
With the width of the nonwoven fabric test piece being 25
mm, the distance between chucks being 100 mm, and the tensile rate
being 100 mm/min, tensile test was performed in two directions:
the machine direction (MD) and the direction crossing the machine
15 direction (CD) , and a maximum tensile load was defined as tensile
strength (N/25 mm) The measurement was performed five times and
an average value of the values obtained five times was calculated.
[0104]
(3) Evaluation of softness
20 In accordance with JIS L1096 (6. 19. 1 A method) , in a constant
temperature chamber at a temperature of 20±2°C and a humidity of
65±2% as specified in JIS Z8703 (standard conditions for testing),
five test pieces each 20 mm in width x 150 mm were collected in
the machine direction (MD). Each test piece was placed on a
S}.^-2350 28
horizontal, smooth-surface table having a 45° slope surface, with
the shorter side of the test piece aligned at the scale baseline.
[0105]
The test piece was slowly slid toward the slope surface by
hand. When the central point on one edge of the test piece touched
the slope surface, the length by which the other edge had moved
was measured by reading the scale. The flexural rigidity was
represented by length (mm) by which the test piece had moved. Each
of the five test pieces was tested on both the front and back
10 surface, and an average value was calculated.
[0106]
Under the measurement method so-called 45° cantilever
method, the test piece of the nonwoven fabric that has moved by
a shorter length (mm) is determined to have more softness.
15 [0107]
In general, when the flexural rigidity value is 50 mm or
less, the softness is determined to be good. However, no
limitation is necessarily made to this value, since required
softness vary depending on use purpose and the like.
20 [0108]
(4) Evaluation of emboss pattern after rubbing
In accordance with ASTM D-5264, a nonwoven fabric test piece
110 mm in width in the machine direction (MD) and 40 mm in width
in the direction crossing the machine direction (CD) of the
F-2350 29
nonwoven fabric was prepared.
[0109]
This nonwoven fabric test piece was fitted to a specimen
holder of Sutherland Ink Rub Tester, and was rubbed ten times with
#40 sandpaper.
[0110]
Then, the nonwoven fabric test piece was placed on a black
cardboard, and was photographed from a height distant from the
test piece by 30 cm.
10 [0111]
The photograph was enlarged, and in a 30 mm square region,
the emboss pattern was observed.
[0112]
When 50% or more of the embossed portion was recognizable,
15 the emboss pattern was evaluated as "recognizable". When less
than 50% of the embossed portion was recognizable, the emboss
pattern was evaluated as "unrecognizable".
[0113] g
[Example 1]
20 As a first propylene polymer, a propylene homopolymer having
a melting point of 162 °C and MFR (measured in accordance with ASTM
D1238 at a temperature of 230°C under a load of 2.16 kg, this
applies hereinafter unless noted particularly otherwise) of 60
g/10 min was used. As a second propylene polymer, a
SF--2350 30
propylene-ethylene random copolymer having a melting point of
142 °C, MFR of 60 g/10 min and 4. 0 me] -% of an ethylene unit component
was used. These were subjected to composite melt spinning by
spunbond method. Then, an eccentric core-sheath composite fiber
5 comprising the propylene homopolymer as a core and the
propylene-ethylene random copolymer as a sheath (core/sheath
=20/80 (weight ratio)) was deposited on a collecting surface.
[0114]
In such a manner as to provide a emboss pattern as shown
10 in Fig. 2 (embossed area percentage: 10%, width of emboss line:
0.25 mm, length of emboss element part: 1.0 to 1.5 mm, interval
between emboss element parts: 005 to 1.0 mm), emboss processing
was performed at an embossing rate 5 m/min and at an embossing
temperature of 110°C, to thereby produce a nonwoven fabric having
15 a basis weight of 30 g/m2 and comprising a crimped composite fiber
having a fineness of structural fibers of 2.5 denier.
[0115]
The resultant nonwoven fabric was subjected to evaluations
as in the above items (1) to (4) The evaluation result is shown
20 in Table 1.
[0116]
[Comparative Example 1]
The operation was performed in the same manner as in Example
1, except that the emboss line of the unit pattern of the embossed
SF-2350 31
portion shown in Fig. 2 was replaced with an emboss line formed
by arranging a plurality of square point shapes with an equal
interval as shown in Fig. 7. Then, evaluations (1) to (4)
described above were performed. The evaluation result is shown
5 in Table 1.
[0117]
[Comparative Example 2]
The operation was performed in the same manner as in Example
1, except that the emboss line of the unit pattern of the embossed
10 portion shown in Fig. 2 was replaced with an emboss line that was
a straight line as shown in Fig. 8, and the embossed area percentage
was 24%. Then, evaluation's (1) to (4) described above were
performed. The evaluation result is shown in Table 1.
[0118]
15 [Table 1]
Examples Ex. 1 Comp. Ex.l Comp. Ex.2
Unit pattern shape o:_ embossed
portion
Fig. 2 Fig. 7 Fig. 8
Area percentage % 10% 10% 24%
Core/sheath ratio 20/80 20/80 20/80
Basisweight g/m2 30 30 30
Embossing rate m/min 5 5 5
Embossing
temperature
oC 110 110 110
Fuzz resistance point 2 4 2
MD tensile strength N/25 mm 20 21 22
CD tensile strength N/25 mm 8 9 8
Flexural rigidity mm 33 38 52
Emboss pattern
after rubbing
visual
observat
ion
Recognizab
le
Unrecogniz
able
Recognizab
le
SF-2350 32
[0119]
According to the evaluation result, the following was made
clear. With regard to (1) fuzz resistance, Example 1 was found
to have fuzz resistance equivalent to that of Comparative Example
5 2. Comparative Example 1 was found to have inferior fuzz
resistance, as compared with Example 1 and Comparative Example
2.
[0120]
With regard to (2) tensile strength, both in the machine
10 direction (MD) and in the direction crossing the machine direction
(CD), Example 1 had equivalent values to the values of
Comparative Examples 1 and 2, and thus Example 1 was found to have
equivalent tensile strength to that of Comparative Examples.
[0121]
15 With regard to (3) softness, Example 1 had a smaller value
than the values of Comparative Example 1 and 2, and thus Example
1 was found to have an emboss pattern superior in softness as
compared with Comparative Example 1 and 2.
[0122]
20 With regard to (4) emboss pattern after rubbing, Example
1 and Comparative Example 2 were found to have recognizable emboss
patterns after rubbing, while Comparative Example 2 was found to
have an unrecognizable emboss pattern after rubbing.
[0123]
SF-2350 33
It was thus found that the nonwoven fabric of the present
invention shown in Example1 was superior particularly in softness
as compared with conventional nonwoven fabrics shown in
Comparative Example 1 and 2; was superior in fuzz resistance to
5 Comparative Example 1 and was good equivalently to Comparative
Example 2; was equivalent in tensile strength to Comparative
Example 1 and 2, and therefore was excellent in the balance among
fuzz resistance, softness, and tensile strength.
[0124]
10 Furthermore, it was found that the emboss pattern after
rubbing of the nonwoven fabric of the present invention was
recognizable equivalently to Comparative Example 2. It was thus
clear that the emboss pattern was retained even through repeated
use and the nonwoven fabric of the present invention was excellent
15 in durability, too.
Reference Signs List
[0125]
10.. nonwoven fabric
20 12. embossed portion
14... non-embossed portion
16.ee emboss line
18... unit pattern
20.- emboss element part
SF-°2350 34
22... arbitrarily-defined point
24... arrow
WI... width of emboss line
W2... length of emboss element part
W3... interval between emboss element part and emboss element
W4... thickness of emboss element part
W5... length of width in MD of unit pattern
W6... length of idth in CD of unit pattern
114... non--embossed portion
10 116... emboss line
118... unit pattern
120._ square point
216_ emboss line
218... unit pattern
15 220_ straight line
SF-2350 35

CLAIMS
1, A nonwoven fabric comprising an embossed portion and
a non-embossed portion,
the embossed portion comprising an emboss pattern that
comprises unit patterns each delimited by emboss lines,
the emboss lines each comprising a plurality of emboss
element parts that are continuously arranged with a predetermined
interval,
10 wherein in the direction in which the distance from an
arbitrarily-defined point in the non-embossed portion within the
unit pattern toward the outside of the emboss lines that delimit
the non-embossed portion is shortest, at least one of the plurality
of emboss element parts is disposed so as to block the direction
15 in which the distance from the arbitrarily-defined point toward
the outside of the emboss lines that delimit the non-embossed
portion is shortest.
2. The nonwoven fabric according to claim 1, wherein the
20 emboss line is formed by disposing the plurality of emboss element
parts with an equal interval from each other so as to form dotted
lines,
3 e The nonwoven fabric according to claim 1 or 2, wherein
SP--2350 36
the emboss line is formed by continuously disposing the plurality
of emboss element parts, each of which is inclined, with an equal
interval from each other.
4. The nonwoven fabric according to any one of claims
1 to 3, wherein the length of the emboss element part is 0.5 to
5 mm, and the interval between the emboss element parts that are
disposed so as to form dotted lines is 0.5 to 5 mm.
10 5. The nonwoven fabric according to any one of claims
1 to 4, wherein the shape of the emboss element part is any of
a straight line, a curved line and a zigzag shape.
6. The nonwoven fabric according to any one of claims
15 1 to 5, wherein the unit patterns each delimited by the emboss
lines are regularly disposed in the machine direction (Machine
Direction) of the nonwoven fabric and in the direction crossing
machine direction (Cross Machine Direction).
20 7. The nonwoven fabric according to claim 6, wherein the
unit pattern has a length of the width in the machine direction
(Machine Direction) of the nonwoven fabric of 2 to 15 mm, and a
length of the width in the direction crossing the machine direction
(Cross Machine Direction) of 2 to 15 mm.
8. The nonwoven fabric according to any one of claims
1 to 7, wherein the line width of the emboss line is 0.5 to 3 mme
9. The nonwoven fabric according to any one of claims
1 to 8, wherein the unit pattern delimited by the emboss lines
is in the shape of rhombus.