U.S. patent application number 13/119003 was filed with the patent office on 2012-05-24 for conjugate fibers for stockings.
This patent application is currently assigned to KB SEIREN, LTD.. Invention is credited to Hiroyuki Manabe, Masashi Ueda.
Application Number | 20120128975 13/119003 |
Document ID | / |
Family ID | 42073493 |
Filed Date | 2012-05-24 |
United States Patent
Application |
20120128975 |
Kind Code |
A1 |
Ueda; Masashi ; et
al. |
May 24, 2012 |
CONJUGATE FIBERS FOR STOCKINGS
Abstract
(A1) Translate this text A composite fiber for stockings which
has water-absorbing properties, hygroscopicity, antistatic
properties, crimp properties, and cool touch is obtained without
sacrificing productivity, transparency, and soft touch. The
composite fiber for stockings is an eccentric composite fiber
comprising a fiber-forming resin (B) and a polyether block amide
copolymer (A). The fiber is characterized in that the polyether
block amide copolymer (A), in a cross section of the fiber, is
exposed in the surface at an angle of 5-90, and the fiber has 1-10
filaments and a fineness of 1-55 dtex. The fiber especially
preferably has a percentage crimp of 10% or higher.
Inventors: |
Ueda; Masashi; (Fukui,
JP) ; Manabe; Hiroyuki; (Fukui, JP) |
Assignee: |
KB SEIREN, LTD.
Fukui
JP
|
Family ID: |
42073493 |
Appl. No.: |
13/119003 |
Filed: |
September 29, 2009 |
PCT Filed: |
September 29, 2009 |
PCT NO: |
PCT/JP2009/066931 |
371 Date: |
June 1, 2011 |
Current U.S.
Class: |
428/370 ;
428/374 |
Current CPC
Class: |
C08L 77/02 20130101;
D01D 5/34 20130101; C08L 77/06 20130101; Y10T 428/2924 20150115;
Y10T 428/2931 20150115; C08L 77/02 20130101; D01D 5/22 20130101;
D01F 8/12 20130101; C08L 2205/02 20130101; C08L 77/06 20130101;
C08G 69/40 20130101; C08L 77/06 20130101; C08L 77/06 20130101 |
Class at
Publication: |
428/370 ;
428/374 |
International
Class: |
D01F 8/12 20060101
D01F008/12; D02G 3/04 20060101 D02G003/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 2008 |
JP |
2008-252284 |
Claims
1. A conjugate fiber for stockings, comprising an eccentric
conjugate fiber made from a fiber-forming resin and a polyether
block amide copolymer, wherein the polyether block amide copolymer
is exposed on the surface of the fiber at an angle of 5 to
90.degree. in a cross-section of the conjugate fiber, the number of
filaments is 1 to 10 in the conjugate fiber, and total fineness is
1 to 55 dtex.
2. The conjugate fiber for stockings according to claim 1, having a
percentage crimp of 10% or higher.
3. The conjugate fiber for stockings according to claim 1, having a
percentage crimp of 40% or higher.
4. The conjugate fiber for stockings according to claim 1, having a
percentage crimp of 50% or higher.
5. The conjugate fiber for stockings according to claim 1, wherein
the fiber-forming resin is polyamide.
Description
TECHNICAL FIELD
[0001] The present invention relates to the conjugate fibers for
stockings.
BACKGROUND ART
[0002] Conventional stockings are made of covered elastic yarn as
knitting yarn. The covered elastic yarn is composed of an elastic
core yarn and polyamide (typically such as nylon 6 or nylon
66)-based filaments as a covering yarn wound around the core
yarn.
[0003] However, the polyamide-based filaments have low
hygroscopicity as compared with natural fibers and therefore, when
the polyamide-based filaments are used in stockings which are worn
in touch with skin, they can cause the wearer stuffy or sticky feel
due to perspiration.
[0004] The polyamide-based filaments also have high charging
ability and therefore, when the polyamide-based filaments are used
in the stockings, a skirt tends to cling to the stockings, which
causes serious comfort issues. A general sweat absorption
processing includes adding an organic polymer compound containing
hydrophilic groups during dyeing or a post treatment after the
dyeing. However, this method provides reduces washing durability
and is not enough solution.
[0005] As a method for imparting certain functionality to a covered
yarn itself, it is well known in the prior art to provide the
covered yarn with water absorbing property by using filaments of a
peculiar cross-section as a covering yarn (Patent Document 1).
[0006] On the other hand, as a method for production of transparent
and soft stockings, it is well known in the prior art to use
conjugate fibers. For example, there is provided a method for
producing hygroscopic, transparent and soft stockings by using
sheath-core conjugate fibers partially composed of a hygroscopic
component such as polyether ester amide (Patent Document 2).
PRIOR ART DOCUMENTS
Patent Documents
[0007] Patent Document 1: Japanese Patent Publication No. 2683646
[0008] Patent Document 2: Japanese Laid-Open Patent Publication No.
H09-41204
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0009] However, covering-type panty stockings such as that
disclosed in Patent Document 1 are inferior in transparency and
texture, even though they are ladies' panty stockings which are
required to be highly fashionable and functional.
[0010] Methods for production of stockings using conjugate fibers
such as that disclosed in Patent Document 2 require wooly
processing because the conjugate fibers are not crimpy, which
causes a problem of productivity.
[0011] Therefore, an object of the present invention is to provide
conjugate fibers for stockings, having water-absorbing property,
hygroscopicity, antistatic property, crimping property, and cool
feeling without sacrificing productivity, transparency and
texture.
Means for Solving the Problems
[0012] The object is achieved by a conjugate fiber for stockings,
comprising an eccentric conjugate fiber made from a fiber-forming
resin and a polyether block amide copolymer, wherein the polyether
block amide copolymer is exposed on the surface of the conjugate
fiber at an angle of 5 to 90.degree. in a cross-section of the
conjugate fiber, the number of filaments is 1 to 10 in the
conjugate fiber, and total fineness is 1 to 55 dtex.
Effects of the Invention
[0013] According to the present invention, it is possible to
provide conjugate fibers for stockings, having high transparency
and soft texture due to high crimping property, high productivity
because of no need for wooly processing, and superior
water-absorbing property, hygroscopicity, antistatic property, and
cool feeling.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is a schematic diagram showing a cross-section of a
conjugate fiber for stockings according to an embodiment of the
present invention;
[0015] FIG. 2 is a schematic diagram showing a cross-section of a
conjugate fiber for stockings according to an embodiment of the
invention; and
[0016] FIG. 3 is a schematic diagram showing a cross-section of a
conjugate fiber for stockings according to an embodiment of the
invention.
EMBODIMENTS FOR CARRYING OUT THE INVENTION
[0017] A conjugate fiber for stockings according to the present
invention is composed of an eccentric composite fiber which is made
from a fiber-forming resin and a polyether block amide
copolymer.
[0018] The fiber-forming resin may be any meltable fiber-forming
resin, examples of which include polyamides such as nylon 6 and
nylon 66; polyesters such as polyethylene terephthalate,
polybutylene terephthalate, polyethylene naphthalate, fully
aromatic polyester, and polylactic acid; polyolefins such as
polyethylene and polypropylene; polymers composed mainly of any of
them; and thermoplastic polymers such as polyphenylene sulfide and
polyether ketone. In particular, polyamide (particularly, nylon 6)
is preferably used, because it has high strength and provides
durability even when it forms thin materials.
[0019] The polyether block amide copolymer may be, for example, a
copolymer produced by copolycondensation of a polyamide unit having
a reactive terminal group and a polyether unit having a reactive
terminal group, such as (1) a diamine-terminated polyamide unit and
a dicarboxyl-terminated polyoxyalkylene unit; (2) a
dicarboxyl-terminated polyamide unit and polyether diol; or (3) a
dicarboxyl-terminated polyamide unit and a diamine-terminated
polyoxyalkylene unit (which can be produced by cyanoethylation and
hydrogenation of a polyoxyalkylene unit having two hydroxyl groups
in .alpha.- and .omega.-positions). In the present invention, the
polyether block amide copolymer is preferably a copolymer produced
by copolycondensation of the materials (2), which is represented by
the following general formula,
HO--(CO--PA-CO--O--PE-O).sub.n--H,
wherein PA represents a polyamide block (hard segment), PE
represents a polyether block (soft segment), and n represents the
number of the repeating units.
[0020] The polyamide unit is preferably nylon 6, nylon 66, nylon
12, or the like, and the polyether unit is preferably polyethylene
glycol, polytetramethylene glycol, or the like.
[0021] The ratio by weight between the "polyamide unit" and the
"polyether unit" is preferably from 99:1 to 5:95, more preferably
from 80:20 to 10:90, and the copolymer whose ratio by weight is
within such range is effectively used.
[0022] As such copolymer, Pebax (registered trademark) series
(manufactured by Arkema) are available in the market, and
particularly, high antistatic property can be achieved by Pebax
MV1074 or Pebax MH1657.
[0023] A cross-sectional shape of the conjugate fiber according to
the present invention will be explained in the following.
[0024] The eccentric conjugate fiber of the present invention is
composed of a fiber made from a combination of the two resins, that
is, a fiber-forming resin and a polyether block amide copolymer, in
which the centers of gravity of the fiber-forming resin and the
polyether block amide copolymer are out of alignment in the
cross-section of the fiber.
[0025] Some examples of the cross-sectional shape of the fiber are
shown in FIGS. 1 to 3. In FIGS. 1 to 3, a character A represents
the polyether block amide copolymer, and a character B represents
the fiber-forming resin.
[0026] The conjugate fibers shown in FIGS. 1 and 2 are of an
eccentric sheath-core type. In the conjugate fiber shown in FIG. 3,
the outer fiber-forming resin B is C-shaped.
[0027] For use in stockings, the conjugate fiber is preferably of
an eccentric sheath-core type as shown in FIGS. 1 and 2 so as to
increase the percentage crimp.
[0028] The fiber may also have two or more sections of polyether
block amide copolymer A. In such a case, the fiber should be
eccentric as a whole.
[0029] As used herein, the term "angle of exposure" means the angle
between two straight lines drawn from the center of the fiber to
two points on the periphery of a fiber in a cross-section of the
fiber, the points corresponding to both ends of an area of a
pertinent section which is exposed on the surface of the fiber.
When two or more sections are exposed on the surface of the fiber,
the angle of exposure is the sum of the angles of exposure of these
sections.
[0030] With respect to the polyether block amide copolymer, an
angle of exposure is required to fall within the range of 5 to
90.degree., preferably 5 to 80.degree.. When the angle of exposure
is within this range, the conjugate fiber is excellent in
water-absorbing properties, hygroscopicity, antistatic property,
and cool feeling, and the conjugate fiber has high productivity and
good dye ability.
[0031] The size (total fineness) of the conjugate fiber of the
present invention falls within the range of 1 to 55 dtex,
preferably 5 to 30 dtex. If the total fineness of the fiber is less
than 1 dtex, the fiber may have practically insufficient
durability, and on the other hand, if the total fineness is more
than 55 dtex, the fiber may tend to have insufficient transparency
or rough and hard texture.
[0032] The conjugate fiber of the present invention is composed of
1 to 10 filaments. Preferably, the fiber is composed of 2 to 7
filaments, so that it can have high transparency, good texture,
soft touch, and high durability.
[0033] According to the present invention, the fiber preferably has
a percentage crimp of 10% or higher. The percentage crimp is more
preferably 40% or higher, particularly preferably 50% or higher.
When the percentage crimp is 10% or higher, the conjugate fiber can
have not only high transparency, good texture and soft touch but
also superior cool feeling. Since the conjugate fiber of the
invention is crimpy, it can be used as it is producing stockings
without any further processing such as wooly processing, which
increases the productivity.
[0034] From the viewpoint of the productivity of spinning and the
workability of dyeing and the like, an area ratio (cross-sectional
area ratio) of the fiber-forming resin to the polyether block amide
copolymer is preferably 90/10 or less. From the viewpoint of
antistatic property and cool feeling, the area ratio of the
fiber-forming resin to the polyether block amide copolymer is
preferably 10/90 or more, particularly preferably 20/80 or
more.
[0035] The conjugate fiber of the present invention can be produced
using a conventional spinning machine for conjugate fiber. The
fiber may be produced by a conventional method in which a spinning
process is performed at a speed of about 500 to about 1,500
m/minute and then a drawing and heat treating process is performed,
or by a high-speed spinning method such as a spin-draw method.
[0036] The fiber-forming resin may contain a small amount of any
other polymer, an antioxidant, a pigment, a delustering agent, an
anti-microbial agent, inert fine particles, or any other
additive.
[0037] The conjugate fiber of the present invention is suitable for
using as a knitting yarn of stockings. Stockings include panty
stockings, short stockings (below the knee), long stockings (up to
the thighs), and other various stockings.
[0038] Stockings may be produced using only the conjugate fibers of
the present invention or using the conjugate fibers of the
invention and any other fibers. Yarn composed of a mixture of the
conjugate fibers of the present invention and natural fibers may
also be used. In these cases, the stockings include 20 to 100% by
weight of the fibers of the present invention, preferably. A basis
weight, gauge and the like of the stockings are not limited, but
may be appropriately determined for any purpose.
[0039] The effective functions of the conjugate fiber can be
imparted to the stockings by the use of the conjugate fiber of the
present invention.
EXAMPLES
[0040] The present invention is more specifically described by the
examples below. It will be understood that the examples are not
intended to limit the scope of the invention. Each of
characteristic values of the examples was determined by the
following methods.
<Water-Absorbing Property>
[0041] The Byreck method was applied. A 20 cm.times.2.5 cm piece of
knitted fabric was used as a sample. The height (cm) of water
soaked up through the sample by capillary action was measured at
the temperature of 20.degree. C. during 10 minutes.
<Hygroscopicity>
[0042] A 20 cm.times.2.5 cm piece of knitted fabric was used as a
sample. The sample was placed in a thermo-hygrostat at 25.degree.
C. and 90% RH, and after 24 hours, the increase in the weight of
the sample was measured. The hygroscopicity was expressed as the
ratio (%) of the increase in the weight to the initial weight.
<Antistatic Property (Friction Electrification Voltage)>
[0043] The friction electrification voltage was measured by the
frictional electrification voltage measurement method according to
JIS L 1094 (1997). [0044] Measurement of friction electrification
voltage: electrostatic tester [0045] Friction cloth: wool, cotton
[0046] Rubbing direction: transverse [0047] Washing process:
performed (three times) [0048] Temperature and humidity: 20.degree.
C. and 33% RH <Cool Feeling (q-max)>
[0049] A BT-Box (10 g/cm.sup.2 in pressure) kept at a temperature
of 33.degree. C. was placed on humidity controlled three-fold
stockings (6 layers) in a room at a temperature of 23.degree. C.
and a humidity of 55% RH, and the heat flux per unit area was
measured under a temperature difference of 10.degree. C. using a
Thermolabo II manufactured by KATO TECH CO., LTD. In this
measurement method, q-max is preferably 0.110 (J/cm.sup.2sec) or
more.
<Angle of Exposure>
[0050] After the conjugate fiber was dyed, the fiber was sliced by
a microtome and a photograph of the cross-section of the fiber was
taken using a stereoscopic microscope. On the photograph, two
straight lines were drawn from the center point of the fiber to two
points on the periphery of the fiber, the points corresponding to
both ends of an area of a pertinent section which is exposed on the
surface of the fiber, and then the angle between those two straight
lines was measured using a protractor.
<Percentage Crimp>
[0051] The percentage crimp is defined as a value calculated from
the following formula.
Percentage crimp=(L0-L1).times.100/L0
[0052] A tension loading of 200 g was applied to a sample
(conjugate fiber), and after a lapse of 1 minute, the length (L0)
thereof was measured.
[0053] Next, the tension loading was removed from the sample, and
the sample was hung with a load of 1 g, after that, the sample was
immersed in hot water at 100.degree. C. for 10 minutes and
air-dried for 16 hours while the 1 g load was applied to the
sample.
[0054] The length (L1) of the air-dried sample was measured, while
the 1 g load was applied to the sample.
Example 1
[0055] a polyether block amide copolymer (Pebax MV1074 manufactured
by Arkema) and nylon 6 (manufactured by Mitsubishi Chemical
Corporation) which were melted separately were spun into a
conjugate fiber (an angle of exposure was 33.5.degree.) at an area
ratio of the copolymer to nylon 6 of 50/50, the conjugate fiber
having the cross-section shown in FIG. 1, and then the undrawn yarn
having the single filament fineness of 35 dtex was taken up.
[0056] The undrawn yarn was drawn at room temperature under the
condition of a draw speed of 800 m/minute and a draw ratio of 3.28
times. The drawn yarn was wound into a pirn at a winding hardness
in the range of 80 to 75, thereby a 22 dtex/2f conjugate fiber for
stockings was obtained.
[0057] No crimp was observed in the appearance of a cop of the
conjugate fiber, but when 1 to 2 minutes had passed since the fiber
was released from the cop, spiral crimps were observed. The
percentage crimp was 62%.
[0058] The conjugate fiber was knitted into stockings using a
4-feeder seamless stocking knitting machine under the condition of
a number of revolutions of 900 rpm. As a result, the conjugate
fiber according to the invention was successfully knitted with no
problem.
[0059] Subsequently, the stockings were dyed at 95.degree. C. and
finished by form setting with steam at 110.degree. C.
[0060] The obtained stockings were well dyed and excellent in
transparency and touch.
[0061] The conjugate fiber according to the present invention could
be used for knitting stockings without any crimp processing because
of its crimp characteristic, thereby high productivity was
achieved.
Example 2
[0062] Stockings were prepared in the same manner as in Example 1,
except that the total fineness/the number of filaments was changed
to 19 dtex/2f.
[0063] The obtained conjugate fiber had a percentage crimp of
52%.
[0064] The obtained stockings were well dyed and excellent in
transparency and touch. The conjugate fiber according to the
present invention could be used for knitting stockings without any
crimp processing because of its crimp characteristic, thereby high
productivity was achieved.
Comparative Example 1
[0065] A thermoplastic polyurethane elastomer (manufactured by
Dainichiseika Color & Chemicals Mtg. Co., Ltd.) and nylon 6
(manufactured by Mitsubishi Chemical Corporation) which were melted
separately were spun into a conjugate fiber (an angle of exposure
was 20.degree.) at an area ratio of the elastomer to nylon 6 of
50/50, the conjugate fiber having the eccentric polycaproamide
sheath-polyurethane core cross-section shown in FIG. 1 and then the
undrawn yarn having the single filament fineness of 31 dtex was
taken up.
[0066] The undrawn yarn was drawn at room temperature under the
conditions of a draw speed of 600 m/minute and a draw ratio of 3.50
times. The drawn yarn was wound into a pirn at a winding hardness
in the range of 80 to 75, thereby a 19 dtex/2f conjugate fiber for
stockings was obtained. The obtained conjugate fiber had a
percentage crimp of 48%.
[0067] The conjugate fiber was used in knitting under the same
conditions as those in Example 1. Subsequently, according to
conventional methods, the stockings were dyed at 95.degree. C. and
finished by form setting with steam at 110.degree. C.
Comparative Example 2
[0068] Stockings were prepared in the same manner as in Example 1,
except that an eccentric sheath-core conjugate fiber (an angle of
exposure was 0.degree.) in which the polyether block amide
copolymer was not exposed to the surface of the fiber was
produced.
[0069] The stockings obtained in Examples 1 and 2 and Comparative
Example 2 were compared with each other with respect to
water-absorbing property. The results are shown in Table 1.
TABLE-US-00001 TABLE 1 Water-absorbing Property (cm) Example 1 0.1
Example 2 0.1 Comparative 0 Example 2
[0070] The stockings obtained in Examples 1 and 2 and Comparative
Examples 1 and 2 were compared with each other with respect to
hygroscopicity. The results are shown in Table 2.
TABLE-US-00002 TABLE 2 Hygroscopicity (%) Example 1 16.9 Example 2
21.1 Comparative 4.0 Example 1 Comparative 13.0 Example 2
[0071] The stockings obtained in Examples 1 and 2 and Comparative
Examples 1 and 2 were compared with each other with respect to
frictional electrification voltage. The results are shown in Table
3.
TABLE-US-00003 TABLE 3 Immedi- ately after After 10 After 30 After
60 Friction rubbing seconds seconds seconds Half life cloth (v) (v)
(v) (v) (v) Example 1 Wool -1450 -140 -120 -100 0.4 Cotton -3240
-210 -160 -130 0.4 Example 2 Wool -3040 -210 -160 -140 0.3 Cotton
-3860 -230 -170 -130 0.3 Comparative Wool -8780 -8620 -8320 -8220
60 Example 1 seconds or more Cotton -11120 -10780 -10620 -10480 60
seconds or more Comparative Wool -10480 -10600 -300 -200 2.5
Example 2 Cotton -9840 -700 -220 -160 2.2
[0072] The stockings obtained in Examples 1 and 2 and Comparative
Example 2 were compared with each other with respect to cool
feeling. The results are shown in Table 4.
TABLE-US-00004 TABLE 4 q-max (W/cm.sup.2) Example 1 0.146 Example 2
0.134 Comparative 0.084 Example 2
INDUSTRIAL APPLICABILITY
[0073] The conjugate fiber of the present invention is suitable for
using in stockings.
DESCRIPTION OF REFERENCE CHARACTERS
[0074] A polyether block amide copolymer. [0075] B fiber-forming
resin.
* * * * *