U.S. patent application number 17/719024 was filed with the patent office on 2022-07-28 for thread.
The applicant listed for this patent is Murata Manufacturing Co., Ltd.. Invention is credited to Hirokazu HAYASHI, Takafumi INOUE, Eiji TAGUCHI, Nobuhito TSUBAKI, Masayuki TSUJI.
Application Number | 20220235496 17/719024 |
Document ID | / |
Family ID | 1000006319788 |
Filed Date | 2022-07-28 |
United States Patent
Application |
20220235496 |
Kind Code |
A1 |
INOUE; Takafumi ; et
al. |
July 28, 2022 |
THREAD
Abstract
A thread that includes a first fiber having at least one groove
extending in a length direction thereof; and at least one second
fiber constructed to generate a potential by external energy. The
second fiber is disposed in a region corresponding to the groove of
the first fiber such that a space is between the groove of the
first fiber and the second fiber.
Inventors: |
INOUE; Takafumi;
(Nagaokakyo-shi, JP) ; TSUBAKI; Nobuhito;
(Nagaokakyo-shi, JP) ; TSUJI; Masayuki;
(Nagaokakyo-shi, JP) ; TAGUCHI; Eiji;
(Nagaokakyo-shi, JP) ; HAYASHI; Hirokazu; (Osaka,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Murata Manufacturing Co., Ltd. |
Nagaokakyo-shi |
|
JP |
|
|
Family ID: |
1000006319788 |
Appl. No.: |
17/719024 |
Filed: |
April 12, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2020/043598 |
Nov 24, 2020 |
|
|
|
17719024 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D02G 3/36 20130101; D10B
2331/041 20130101; D02G 3/34 20130101; D02G 3/38 20130101; D02G
3/045 20130101 |
International
Class: |
D02G 3/36 20060101
D02G003/36; D02G 3/34 20060101 D02G003/34; D02G 3/04 20060101
D02G003/04; D02G 3/38 20060101 D02G003/38 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 26, 2019 |
JP |
2019-212975 |
Claims
1. A thread comprising: a first fiber having at least one groove
extending in a length direction thereof; and at least one second
fiber constructed to generate a potential by external energy, the
second fiber disposed in a region corresponding to the groove of
the first fiber such that a space is between the groove of the
first fiber and the second fiber.
2. The thread according to claim 1, wherein a cross section of the
space between the first fiber and the second fiber is smaller than
a cross section of the thread.
3. The thread according to claim 1, wherein a shape of the groove
of the first fiber corresponds to a shape along a surface of the
second fiber.
4. The thread according to claim 1, wherein a shape of the groove
of the first fiber does not correspond to a shape along a surface
of the second fiber.
5. The thread according to claim 1, wherein the first fiber and the
second fiber are modified cross-section fibers, the second fiber
has at least one protrusion extending in the length direction
thereof, and the second fiber is disposed such that the protrusion
engages with the groove of the first fiber.
6. The thread according to claim 1, wherein the first fiber has a
lower elastic modulus than the second fiber.
7. The thread according to claim 1, wherein the first fiber has a
higher coefficient of static friction than the second fiber.
8. The thread according to claim 1, wherein an opening width of the
groove substantially matches a diameter of the second fiber.
9. The thread according to claim 1, wherein an opening width of the
groove is larger than a diameter of the second fiber.
10. The thread according to claim 1, wherein the second fiber
contains a polylactic acid.
11. The thread according to claim 1, wherein the first fiber is
longer than the second fiber.
12. The thread according to claim 1, wherein the first fiber is
shorter than the second fiber.
13. The thread according to claim 1, wherein the first fiber and
the second fiber are twisted together.
14. The thread according to claim 1, wherein the first fiber has a
plurality of grooves extending in the length direction thereof; and
a plurality of second fibers, a respective second fiber of the
plurality of second fibers being disposed in a region corresponding
to a respective groove of the plurality of grooves of the first
fiber.
15. The thread according to claim 1, wherein a sectional shape of
the first fiber is a cross shape, a star polygon, or a concave
polygon.
16. The thread according to claim 1, wherein a cross section of the
at least one groove is V-shaped, and a cross section of the at
least one second fiber is circular.
17. The thread according to claim 1, wherein the thread comprises a
plurality of the first fibers and a plurality of the second fibers
arranged to surround the plurality of first fibers.
18. The thread according to claim 1, wherein both the first fiber
and the second fiber are constructed to generate a potential by
external energy.
19. The thread according to claim 1, wherein the first fiber and
the second fiber have the same sectional shape.
20. The thread according to claim 1, wherein the at least one
groove is parallel to the length direction of the first fiber.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of International
application No. PCT/JP2020/043598, filed Nov. 24, 2020, which
claims priority to Japanese Patent Application No. 2019-212975,
filed Nov. 26, 2019, the entire contents of each of which are
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a thread formed by twisting
different fibers.
BACKGROUND OF THE INVENTION
[0003] In recent years, in order to realize a comfortable and
healthy life style, various daily life products with improved
comfort, health, or hygiene have been devised. In particular,
clothing made of fibers having antifungal properties have been
devised. The fibers having antifungal properties are, for example,
charge generating fibers that exhibit antifungal properties by
charge generated by a piezoelectric effect. The piezoelectric
thread disclosed in Patent Document 1 is an example of charge
generating fiber. When tension is applied to the piezoelectric
thread, charge is generated on the surface of the piezoelectric
thread, and an electric field is generated in a space formed
between fibers by the charge. The piezoelectric thread exerts an
effect such as an antifungal effect by the generated electric
field. [0004] Patent Document 1: International Publication No.
2017/212836
SUMMARY OF THE INVENTION
[0005] There is room for improvement in a conventional charge
generating fiber in terms of constraining a fungus in the vicinity
of the space where an electric field is generated.
[0006] Therefore, an object of the invention is to provide a thread
having a better antifungal effect than a conventional charge
generating thread having antifungal properties.
[0007] A thread of the invention includes a first fiber having at
least one groove extending in a length direction thereof; and at
least one second fiber constructed to generate a potential by
external energy. The second fiber is disposed in a region
corresponding to the groove of the first fiber such that a space is
between the first fiber and the second fiber.
[0008] In the thread of the invention, the second fiber is disposed
in the region corresponding to the groove of the first fiber, and a
space is formed between the first fiber and the second fiber, so
that an electric field can be generated in the space. In addition,
since the groove is formed in the first fiber, the surface area of
the first fiber increases, and a fungus easily adhere to the first
fiber. Thus, the thread including the first fiber and the second
fiber exhibits a good antifungal effect.
[0009] According to the present invention, a thread that gives a
space in which a good electric field is generated can be
realized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1(A) is a view illustrating a configuration of a thread
according to one embodiment of the present invention. FIG. 1(B) is
a sectional view taken along the line I-I in FIG. 1(A). FIG. 1(C)
is a view illustrating applying a twist to a first fiber and second
fibers of the thread.
[0011] FIGS. 2(A) to 2(C) are views showing a sectional shape of
the first fiber, respectively.
[0012] FIGS. 3(A) and 3(B) are views showing a relation among
deformation, a uniaxial stretching direction, and an electric field
direction of a second fiber when the second fiber is a polylactic
acid (PLLA) uniaxially stretched.
[0013] FIG. 4(A) is a view illustrating a configuration of a thread
according to one embodiment of the invention. FIG. 4(B) is a
sectional view taken along the line II-II of FIG. 4(A). FIG. 4(C)
is a view illustrating applying a twist to a first fiber and a
second fiber of the thread.
[0014] FIG. 5 is a view illustrating an electric field in a
thread.
[0015] FIG. 6 is a sectional view of a thread according to one
embodiment of the invention.
[0016] FIG. 7 is a sectional view of a thread according to one
embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] FIG. 1(A) is a view illustrating a configuration of a thread
1 according to one embodiment of the invention. FIG. 1(B) is a
sectional view taken along the line I-I in FIG. 1(A). FIG. 1(C) is
a view illustrating applying a twist to a first fiber 10 and second
fibers 20 of the thread 1.
[0018] The thread 1 is composed of a first fiber 10 and second
fibers 20. The first fiber 10 has at least one a groove 12
extending in a length direction, and is surrounded by a plurality
of second fibers 20. When energy is applied to the second fibers
20, charge is generated. In the thread 1 of the present embodiment,
the second fibers 20 are disposed to fit within the groove 12 of
the first fiber 10, and are twisted together with the first fiber
10. In FIG. 1(B), as an example, a cross section of one first fiber
10 and six second fibers 20 is illustrated in a cross section taken
along the line I-I, but the number of first fibers 10 and the
number of second fibers 20 are not limited to this, and are
actually set as appropriate in consideration of the application and
the like.
[0019] Conventionally, it has been known that proliferation and
metastasis of a bacterium, a fungus, and the like can be suppressed
by an electric field (See, for example, Tetsuaki Tsuchido, Hiroki
Kourai, Hideaki Matsuoka, Junichi Koizumi, Kodansha: Microbial
Control--Science and Engineering. In addition, see, for example,
Koichi Takaki, Application of High Voltage and Plasma Technology to
Agricultural and Food Field, J. HTSJ, Vol. 51, No. 216). In
addition, a potential generating the electric field may cause a
current to flow through a current path formed by moisture or a
circuit formed by a micro discharge phenomenon. It is considered
that this current weakens a fungus and suppresses proliferation and
metastasis of the fungus.
[0020] When the thread 1 of the embodiment receives external energy
(for example, when a tension is applied in an axial direction of
the thread 1), charge is generated, and an electric field is
generated. Alternatively, when the thread 1 receiving external
energy is brought close to a thing having a predetermined potential
(including a ground potential) such as a human body, an electric
field is also generated between the thread 1 and the thing. When
the thread 1 receives external energy and is close to a thing
having a predetermined potential (including a ground potential)
such as a human body, a current flows between the thread 1 of the
present invention and the thing through a liquid such as sweat.
[0021] Disruption of a cell of a fungus and degeneration of the
cytoplasm occur by an electric field or an electric current.
Therefore, the cell of the fungus and the electron transmission
system for maintaining the life of the fungus are disturbed, and
the fungus is killed or the fungus itself is weakened. In addition,
oxygen contained in a liquid such as sweat or water may be changed
into an active oxygen species by an electric field or a current.
Active oxygen species includes an oxygen radical, and these effects
kill or weaken a fungus. Thus, the thread 1 has a remarkable
antifungal effect. In the present description, the "antifungal
effect" is a concept including both an effect of killing a fungus
and an effect of weakening a fungus.
[0022] In the embodiment, the first fiber 10 is a modified
cross-section fiber (modified filament) made of a fiber material
such as a polyester, a nylon, or an acrylic. FIGS. 2(A) to 2(C) are
views showing a sectional shape of the first fiber 10,
respectively. As illustrated in FIGS. 2(A) to 2(C), the sectional
shape of the first fiber 10 is a cross shape, a star polygon, or a
concave polygon. In any example, the first fiber 10 has the groove
12 and protrusion 14 extending in the longitudinal direction.
[0023] Furthermore, in the embodiment, the second fiber 20 is made
of, for example, a piezoelectric polymer. Examples of the
piezoelectric polymer include a polyvinylidene fluoride (PVDF) and
a polylactic acid (PLA), and any of them can be used as a raw
material of the second fiber 20. Among them, the polylactic acid
(PLA) is a piezoelectric polymer having no pyroelectricity. The
polylactic acid is uniaxially stretched to generate
piezoelectricity. The polylactic acid includes PLLA having a
right-handed helical structure obtained by polymerizing an L-form
monomer and PDLA having a left-handed helical structure obtained by
polymerizing a D-form monomer and having a polarity of a
piezoelectric constant opposite to that of PLLA.
[0024] FIGS. 3(A) and 3(B) are views showing a relation among
deformation, a uniaxial stretching direction, and an electric field
direction of the second fiber 20 when the second fiber 20 is a
polylactic acid (PLLA) uniaxially stretched. FIGS. 3(A) and 3(B)
are views when the second fiber 20 is assumed to have a film shape
as a model case. In the embodiment, the second fiber 20 is a
circular cross section fiber (circular filament).
[0025] The polylactic acid (PLA) is a chiral polymer, and its main
chain has a helical structure. When the polylactic acid is
uniaxially stretched and molecules are oriented, piezoelectricity
appears. When heat treatment is further performed to increase the
crystallinity, the piezoelectric constant increases. The second
fiber 20 made of a uniaxially stretched polylactic acid has a
tensor component of d.sub.14 and d.sub.25 as the piezoelectric
strain constant when a thickness direction is defined as a first
axis, a stretching direction 900 is defined as a third axis, and a
direction orthogonal to both the first axis and the third axis is
defined as a second axis. Therefore, when the second fiber 20 made
of a uniaxially stretched polylactic acid is distorted in a
direction of 45 degrees with respect to the uniaxially stretched
direction, charge is generated.
[0026] As shown in FIG. 3(A), when the second fiber 20 shrinks in
the direction of the first diagonal line 910A and extends in the
direction of the second diagonal line 910B orthogonal to the first
diagonal line 910A, an electric field is generated in a direction
from the back side to the front side of the paper surface. That is,
in the state of FIG. 3(A), a negative charge is generated on the
front side of the paper surface. As shown in FIG. 3(B), when the
second fiber 20 extends in the direction of the first diagonal line
910A and shrinks in the direction of the second diagonal line 910B,
charge is also generated. In this case, the polarity is reversed,
and an electric field is generated in a direction from the surface
to the back side of the paper surface. That is, in the state of
FIG. 3(B), a positive charge is generated on the front side of the
paper surface.
[0027] The polylactic acid has piezoelectricity due to orientation
of molecules by stretching, and thus does not need poling unlike
other piezoelectric polymers such as PVDF or piezoelectric
ceramics. The piezoelectric constant of the uniaxially stretched
polylactic acid is about 5 to 30 pC/N, and has a very high
piezoelectric constant among polymers. Furthermore, the
piezoelectric constant of the polylactic acid does not vary with
time and is extremely stable.
[0028] As illustrated in FIG. 1(C), the second fibers 20 having the
characteristics are twisted together with the first fiber 10 to the
left to obtain the thread 1. The thread 1 is S-twisted
(right-twisted). In FIG. 1(A), since the plurality of second fibers
20 are twisted, the stretching direction (length direction) 900 of
each second fiber 20 is inclined obliquely with respect to the
stretching direction of the thread 1. In other words, the
stretching direction 900 of the second fibers 20 is inclined to the
left on the paper surface with respect to the stretching direction
of the thread 1.
[0029] Ideally, the angle (twist angle of the second fibers 20)
between stretching direction 900 of the second fibers 20 and the
stretching direction of the thread 1 is preferably 45 degrees. When
such a thread 1 is stretched under tension, the second fibers 20
are stretched along the axial direction of the thread 1, and are
shrunk along the width direction of the thread 1. Therefore, the
axial direction of the thread 1 corresponds to the second diagonal
line 910B illustrated in FIG. 3(A), and the width direction of the
thread 1 corresponds to the first diagonal line 910A illustrated in
FIG. 3(A). As in the example shown in FIG. 3(A), the second fiber
20 stretches in the direction corresponding to the second diagonal
line 910B and shrinks in the direction corresponding to the
direction of the first diagonal line 910A. Therefore, a negative
charge is generated on the surface of the second fiber 20, and a
positive charge is generated on the inner side. That is, in the
second fiber 20, charge is generated by external energy.
[0030] Of course, the inclination of the second fiber 20 with
respect to the axial direction of the thread 1 is not limited to 45
degrees to the left. When a shearing stress is applied to the
second fiber 20, charge is generated. Therefore, the stretching
direction 900 of the second fiber 20 may cross at least the axial
direction of the thread 1. Considering this, the twist angle of the
second fiber 20 may be larger than 0 degrees and smaller than 90
degrees to the left. In general, as the twist angle of the second
fiber 20 approaches 45 degrees to the left, the charge generation
efficiency is improved. However, usually, the thread is used for
knitted fabrics, textile fabrics, and sewing, and the direction in
which the thread extends may not be constant. That is, since an
external force is not necessarily applied in the long axis
direction of the thread, the twist angle of the second fiber 20 is
not limited to the above.
[0031] In the embodiment, since the first fiber 10 has the groove
12, the surface area of the first fiber 10 is larger than that of a
fiber having no groove, and the possibility that fungus adheres to
the first fiber 10 is relatively high. As shown in FIG. 1(C), when
the first fiber 10 having the groove 12 in the length direction is
twisted, the groove 12 extends helically. The shape of the groove
12 is a shape along a surface of the second fiber 20. In such a
configuration, when the second fiber 20 is twisted, the second
fiber 20 is twisted along the groove 12 of the first fiber 10. In
other words, the second fiber 20 is twisted while being guided by
the groove 12 of the first fiber 10. The opening width of the
groove 12 is substantially equal to or larger 20 than the diameter
length of the second fiber 20. At this time, by increasing the
friction coefficient of one of the first fiber 10 and the second
fiber 20, when the first fiber 10 and the second fiber 20 are
stressed against each other, stress can be efficiently applied to
the other, and generation of charge can be improved.
[0032] Further, as shown in FIG. 1(C), in the embodiment, a space
SP is formed between the groove 12 of the first fiber 10 and the
second fiber 20 disposed in the region formed in the groove 12. In
FIG. 1(C), the cross section of the groove 12 is V-shaped, but the
cross section of the second fiber 20 is circular form. Therefore,
since the second fiber 20 and the groove 12 are not engaged exactly
with each other, the space SP is generated. With such a space SP, a
leakage electric field is likely to be formed. Therefore, the
thread 1 exerts a good antifungal effect. The shape of the space SP
can be changed by changing the shape of the groove 12 of the first
fiber 10, and the optimum leakage electric field can be changed in
combination with the second fiber 20.
[0033] The cross section of the space SP is smaller than the cross
section of the thread 1. The space SP may be smaller than the cross
section of the first fiber 10 or smaller than the cross section of
the second fiber 20.
[0034] FIG. 4(A) is a view illustrating a configuration of a thread
2 according to one embodiment of the invention. FIG. 4(B) is a
sectional view taken along line II-II of FIG. 4(A). FIG. 4(C) is a
view illustrating applying a twist to a first fiber 10 and second
fibers 20 of the thread 2. In the thread 2 of the embodiment, the
second fibers 20 are twisted rightward together with the first
fiber 10. That is, the thread 2 is Z-twisted (left-twisted). In
FIG. 4(A), the stretching direction 900 of the second fibers 20 is
inclined to the right on the paper surface with respect to the
stretching direction of the thread 2.
[0035] As in the thread 1, in the thread 2, the angle between the
stretching direction 900 of the second fiber 20 and the stretching
direction of the thread 2 is ideally preferably 45 degrees. When
such a thread 2 is stretched under tension, the second fibers 20
are stretched along the axial direction of the thread 2, and are
shrunk along the width direction of the thread 2. Therefore, the
stretching direction of the thread 2 corresponds to the first
diagonal line 910A illustrated in FIG. 3(B), and the width
direction of the thread 2 corresponds to the second diagonal line
910B illustrated in FIG. 3(B). As in the example shown in FIG.
3(B), the second fiber 20 stretches in the direction corresponding
to the first diagonal line 910A and shrinks in the direction
corresponding to the direction of the second diagonal line 910B.
Therefore, a positive charge is generated on the surface of the
thread 2, and a negative charge is generated on the inner side.
[0036] Since charge generates when the shearing stress is applied
in the second fiber 20, the inclination with respect to the
stretching direction of the thread 2 is not limited to 45 degrees
to the right, and may at least intersect with the stretching
direction of the thread 2. However, as the twist angle of the
second fiber 20 approaches 45 degrees to the right, the charge
generation efficiency is improved. In the embodiment, the groove 12
of the first fiber 10 is a V-shaped groove, and a surface of the
second fiber 20 is arcuate. That is, the shape of the groove 12 of
the first fiber 10 is a shape that is not along the surface of the
second fiber 20. However, in other embodiments, the shape of the
groove 12 of the first fiber 10 may be a shape along the surface of
the second fiber 20. For example, the groove 12 of the first fiber
10 is a semicircular groove, and the surface of the second fiber 20
is arcuate. Furthermore, usually, the thread is used for knitted
fabrics, textile fabrics, and sewing, and the direction in which
the thread extends may not be constant. That is, since an external
force is not necessarily applied in the long axis direction of the
thread, the twist angle of the second fiber 20 is not limited to
the above.
[0037] As shown in FIG. 4(C), since there is a space SP between the
groove 12 of the first fiber 10 and the second fiber 20 disposed to
fit the groove 12, a leakage electric field is easily formed.
Therefore, the thread 2 has the same good antifungal effect as the
thread 1.
[0038] FIG. 5 is a view illustrating an electric field in the
thread 1 and the thread 2. In the thread 1 alone, the surface has a
negative potential and the inside has a positive potential when
tension is applied. In the thread 2 alone, the surface has a
positive potential and the inside has a negative potential when
tension is applied. When the thread 1 and the thread 2 are brought
close to each other, the close portions (surfaces) tend to have the
same potential. In this case, the proximity portion between the
thread 1 and the thread 2 becomes 0 V, and the positive potential
inside the thread 1 is further increased so as to maintain the
original potential difference. Similarly, the negative potential
inside the thread 2 is further lowered.
[0039] An electric field directed mainly from the inside to the
outside of the thread 1 is formed in the cross section of the
thread 1, and an electric field directed mainly from the outside to
the inside the thread 2 is formed in the cross section of the
thread 2. When the thread 1 and the thread 2 are brought close to
each other, these electric fields leak out into the air and are
synthesized, and an electric field is formed by a potential
difference between the thread 1 and the thread 2 as illustrated in
FIG. 5. Alternatively, when the thread 1 (or the thread 2) and a
thing having a predetermined potential (including a ground
potential) such as a human body are brought close to each other, an
electric field is generated between the thread 1 (or the thread 2)
and the thing close to the thread 1 (or the thread 2).
[0040] Alternatively, a current may flow through a current path
formed by moisture between the thread 1 and the thread 2, or a
circuit formed by a micro discharge phenomenon. Even when the
thread 1 or the thread 2 and a thing having a predetermined
potential close to each other are brought close to each other, a
current may flow through a current path formed by moisture, or a
circuit formed by a micro discharge phenomenon.
[0041] Furthermore, the thread 1 and the thread 2 do not need to
have potentials of opposite polarity. Even if the thread 1 and the
thread 2 have potentials of the same polarity, an electric field or
a current is generated if there is a potential difference between
them. That is, the thread 1 and the thread 2 may have different
potentials when charges are generated.
[0042] As the fiber that generates a negative charge on the
surface, a Z thread using PDLA is also conceivable in addition to
an S thread using PLLA. Furthermore, as the fiber that generates a
positive charge on the surface, the S thread using PDLA is also
conceivable in addition to the Z thread using PLLA.
[0043] In the embodiment, only the second fiber 20 contains the
polylactic acid. However, in other embodiments, the first fiber 10
may also contain the polylactic acid. Then, when the first fiber 10
is twisted, charge is generated.
[0044] In the embodiment, the number of the first fibers 10 in the
thread 1 or the thread 2 is 1, but in other embodiments, the number
of the first fibers 10 may be plural. FIG. 6 is a sectional view of
a thread according to one embodiment of the invention. As shown in
FIG. 6, a plurality of first fibers 10 are disposed so as to be
surrounded by second fibers 20. The bundle of first fibers 10 has
more grooves 12 than the single first fiber 10. In such a
configuration, when the first fibers 10 and the second fibers 20
are twisted, the bundle of the first fibers 10 can guide more the
second fibers 20.
[0045] In the embodiment, the first fiber 10 and the second fiber
20 are long fibers (filaments), and the thread 1 and the thread 2
are twisted threads made of long fibers. However, the thread 1 and
thread 2 are not limited to the twisted threads made of long
fibers. In another embodiment, the first fiber 10 and the second
fiber 20 may be short fibers (spans), and the thread 1 and the
thread 2 may be spun threads made of short fibers. In other
embodiments, the first fiber 10 and the second fiber 20 may be long
fibers and short fibers (or short fibers and long fibers),
respectively, and the thread 1 and the thread 2 may be twisted
threads made of two types of fibers.
[0046] In the embodiment, the first fibers 10 are heteromorphic
modified cross-section fibers (modified filaments) and the second
fibers 20 are circular cross-section fibers (circular filaments).
However, the second fibers 20 are not limited to the circular
cross-section fibers. In another embodiment, the second fibers 20
are a modified cross-section fibers like the first fibers 10.
[0047] In other embodiments, both the first fiber 10 and the second
fiber 20 may be charge generating fibers that generate charge.
Furthermore, when both the first fiber 10 and the second fiber 20
are charge generating fibers, either one may have a lower elastic
modulus than the other, and when only one of the first fiber 10 and
the second fiber 20 is charge generating fiber, the other may have
a lower elastic modulus than the one. In this case, since the fiber
has a low elastic modulus, the thread tends to stretch, and the
shearing stress tends to be applied to the charge generating fiber.
Furthermore, when both of the first fiber 10 and the second fiber
20 are charge generating fibers, either one may have a lower
coefficient of static friction than the other, and when only one of
the first fiber 10 and the second fiber 20 is charge generating
fiber, the other may have a higher coefficient of static friction.
In this case, the shearing stress tends to be applied to the charge
generating fiber.
[0048] FIG. 7 is a sectional view of a thread 3 according to one
embodiment of the invention. In this embodiment, a thread 3 is
composed of the first fiber 10 and the second fiber 20 which are
modified cross-section fibers, and the first fiber 10 and the
second fiber 20 have the same sectional shape. However, in other
embodiments, the first fiber 10 and the second fibers 20 in the
thread 3 may have different sectional shapes.
[0049] As illustrated in FIG. 7, the second fiber 20 has at least
one protrusion 24 extending in the length direction. The second
fiber 20 is disposed such that the protrusion 24 of the second
fiber 20 engages with the groove 12 of the first fiber 10. In such
a configuration, when the second fiber 20 is twisted, the
protrusion 24 of the second fiber 20 is twisted along the groove 12
of the first fiber 10, and extends helically. That is, the second
fiber 20 is twisted while being guided by the groove 12 of the
first fiber 10.
[0050] The thread 3 is S-twisted or Z-twisted depending on the
direction of twisting. In the embodiment, by using the groove 12 of
the first fiber 10 and the protrusion 24 of the second fiber 20,
the twist angle of the second fiber 20 can be made close to a
desired angle (45 degrees to the left or 45 degrees to the right),
and the thread 3 can be made into a medium twisted thread or a hard
twisted thread. Since the shape and size of the internal space of
the groove 12 do not exactly fit the shape and size of the
protrusion 24, the space SP exists between the first fiber 10 and
the second fiber 20. Therefore, a leakage electric field is easily
formed. Such a thread 3 has the same good antifungal effect as the
thread 1 and the thread 2.
[0051] In the embodiment, the groove 12 of the first fiber 10 is
parallel to the length direction of the first fiber 10 as shown in
FIG. 1(C). However, the groove 12 is not limited to the linear
groove. In another embodiment, the groove 12 of the first fiber 10
is a groove formed in a helical shape with respect to the axial
direction of the first fiber 10. When the second fiber 20 is wound
along the helical groove, a thread having an appearance similar to
that of the twisted thread is obtained. In this embodiment, it is
not necessary to twist the first fiber 10. The number of turns and
the helical angle of the second fiber 20 are determined by the
installation state of the helical groove. Therefore, if the number
of turns and the helical angle are appropriate, the thread obtained
in this embodiment can also exhibit a good antifungal effect.
[0052] The above-mentioned threads (thread 1, thread 2, thread 3,
etc.) can be applied to daily life products such as medical parts
and clothing. For example, the thread (thread 1, thread 2, thread
3, etc.) can be applied to a mask, underwear (in particular,
socks), a towel, insoles such as shoes and boots, sportswear in
general, a hat, bedding (bedclothes, a mattress, a sheet, a pillow,
a pillow cover, and the like), a toothbrush, a froth, a water
purifier, a filter for an air conditioner or an air cleaner, a
stuffed toy, a pet-related product (a mat for a pet, clothing for a
pet, and an innerwear for a pet), various mat products (a foot, a
hand, and a toilet seat), s curtain, s kitchen utensil (s sponge or
s cloth), seats (a seats for a car, a train, an airplane, etc.), a
cushioning material for a motorbike helmet and an exterior material
thereof, a sofa, a bandage, a gauze, a suture, clothes for a doctor
and a patient, a supporter, a sanitary product, a sporting good (an
inner of a wear and a glove, an arm guard used in a martial art, or
the like), a filter for an air conditioner or an air cleaner, a
packaging material, and a screen door.
[0053] Of the clothing, in particular, socks (or supporters) always
expand and contract along a joint by movement such as walking, and
thus the thread (thread 1, thread 2, thread 3, etc.) generates
charge with high frequency. In addition, socks absorb moisture such
as sweat and become a hotbed for proliferation of a fungus, but the
threads (thread 1, thread 2, thread 3, etc.) can suppress
proliferation of a fungus, and thus exert a remarkable effect as a
fungus-countermeasure application for odor prevention.
[0054] Finally, description of this embodiment should be considered
to be exemplary in all respects and not restrictive. The scope of
the present invention is defined not by the embodiments but by the
claims. Furthermore, the scope of the invention is intended to
include all modifications within the meaning and scope equivalent
to the claims.
DESCRIPTION OF REFERENCE SYMBOLS
[0055] 1, 2, 3: Thread [0056] 10: First fiber [0057] 20: Second
fiber [0058] 12: Groove [0059] 14, 24: Protrusion [0060] SP: Space
[0061] 900: Stretching direction [0062] 910A: First diagonal line
[0063] 910B: Second diagonal line
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