U.S. patent application number 15/781519 was filed with the patent office on 2018-12-20 for moisture-absorbing core-sheath composite yarn, and fabric.
The applicant listed for this patent is Toray Industries, Inc.. Invention is credited to Yoshifumi Sato, Kentaro Takagi, Daisuke Yoshioka.
Application Number | 20180363169 15/781519 |
Document ID | / |
Family ID | 59013051 |
Filed Date | 2018-12-20 |
United States Patent
Application |
20180363169 |
Kind Code |
A1 |
Takagi; Kentaro ; et
al. |
December 20, 2018 |
MOISTURE-ABSORBING CORE-SHEATH COMPOSITE YARN, AND FABRIC
Abstract
A moisture-absorbing core-sheath composite yarn has a sheath
polymer made of a polyamide, a core polymer is a
polyetheresteramide copolymer, and the strength retention after a
150.degree. C. 1-hour dry heat treatment is 50% or higher. The
core-sheath composite yarn has high moisture-absorbing performance,
is more comfortable than natural fibers, and can retain the soft
texture, durability, and moisture-absorbing/releasing performance
even when laundered and dried repeatedly.
Inventors: |
Takagi; Kentaro;
(Nagoya-shi, JP) ; Sato; Yoshifumi; (Nagoya-shi,
JP) ; Yoshioka; Daisuke; (Nagoya-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Toray Industries, Inc. |
Tokyo |
|
JP |
|
|
Family ID: |
59013051 |
Appl. No.: |
15/781519 |
Filed: |
November 14, 2016 |
PCT Filed: |
November 14, 2016 |
PCT NO: |
PCT/JP2016/083644 |
371 Date: |
June 5, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D02G 3/02 20130101; D01D
5/098 20130101; D01D 5/34 20130101; D01F 8/12 20130101; D01F 8/16
20130101; D10B 2401/02 20130101; D04B 1/16 20130101; D10B 2331/02
20130101; D10B 2401/022 20130101; D03D 15/0027 20130101; D10B
2331/06 20130101; D02G 3/045 20130101 |
International
Class: |
D01F 8/12 20060101
D01F008/12; D04B 1/16 20060101 D04B001/16; D01F 8/16 20060101
D01F008/16; D01D 5/098 20060101 D01D005/098; D02G 3/04 20060101
D02G003/04; D01D 5/34 20060101 D01D005/34 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 8, 2015 |
JP |
2015-239504 |
Claims
1-3. (canceled)
4. A hygroscopic core-sheath composite yarn comprising polyamide as
a sheath polymer and a polyether ester amide copolymer as a core
polymer, the yarn having a strength retention rate of 50% or more
after undergoing dry heat treatment at 150.degree. C. for 1
hour.
5. The hygroscopic core-sheath composite yarn as set forth in claim
4, having a .DELTA.MR value of 5.0% or more and a .DELTA.MR
retention rate of 70% or more after undergoing dry heat treatment
at 150.degree. C. for 1 hour.
6. A fabric comprising, at least partly, a hygroscopic core-sheath
composite yarn as set forth in claim 4.
7. A fabric comprising, at least partly, a hygroscopic core-sheath
composite yarn as set forth in claim 5.
Description
TECHNICAL FIELD
[0001] This disclosure relates to a hygroscopic core-sheath
composite yarn and fabric.
BACKGROUND
[0002] Synthetic fibers made of thermoplastic resins including
polyamide and polyester are widely used for clothing and industrial
applications because of being high in strength, chemical
resistance, heat resistance and the like.
[0003] In particular, in addition to its unique characteristics
including softness, high tensile strength, coloring property in
dyeing processes, and high heat resistance, polyamide fiber is so
high in hygroscopicity that it is widely used for applications such
as inner wear and sports wear. However, polyamide fibers are not
sufficiently hygroscopic compared to natural fibers such as cotton
and have some problems such as undesired stuffiness and stickiness,
leading to inferior comfortability to natural fibers.
[0004] Against this background, synthetic fibers showing excellent
moisture absorbing and releasing properties that prevent stuffiness
and stickiness and having comfortability similar to that of natural
fibers are now demanded mainly for innerwear and sports apparel
applications.
[0005] Then, the addition of a hydrophilic chemical compound to a
polyamide fiber has been studied most widely. For example, Japanese
Unexamined Patent Publication (Kokai) No. HEI 09-188917 proposes a
method of improving hygroscopic performance by blending
polyvinylpyrrolidone, used as a hydrophilic polymer, with
polyamide, followed by spinning.
[0006] On the other hand, there have been many studies that attempt
to produce fibers having a core-sheath structure composed mainly of
a highly hygroscopic thermoplastic resin as the core component and
a thermoplastic resin with excellent mechanical properties as the
sheath component, in an attempt to provide a fiber having both high
moisture absorbing performance and good mechanical properties.
[0007] For example, International Publication WO 2014/10709
discloses a core-sheath composite fiber composed mainly of a core
component and a sheath component such that the core component is
not exposed in the fiber surface. In this core-sheath composite
fiber, the core component is a polyether block amide copolymer
containing 6-nylon as a hard segment whereas the sheath component
is a 6-nylon fiber, wherein the area ratio between the core
component and the sheath component in the cross section of the
fiber is 3/1 to 1/5.
[0008] Japanese Unexamined Patent Publication (Kokai) No. HEI
06-136618 discloses a sheath-core type composite fiber containing a
thermoplastic resin as the core component and a fiber-forming
polyamide resin as the sheath component, wherein the main
constituent of the thermoplastic resin in the core component is a
polyether ester amide, the core component accounting for 5% to 50%
by weight of the total weight of the composite fiber. The document
describes a highly hygroscopic core-sheath type composite fiber
with the above feature containing polyether ester amide as the core
component and polyamide as the sheath component.
[0009] In addition, Japanese Unexamined Patent Publication (Kokai)
No. HEI 08-209450 describes a composite fiber having moisture
absorbing and releasing properties characterized by containing
polyamide or polyester as the sheath component and a thermoplastic
water absorbing resin made of crosslinked polyethylene oxide as the
core component. The document mentions a highly hygroscopic
core-sheath composite fiber containing a highly hygroscopic
water-insoluble modified polyethylene oxide as the core component
and polyamide as the sheath component.
[0010] However, although having moisture absorbing and releasing
properties similar to those of natural fibers, the fiber described
in JP '917 does not have satisfactorily high performance, and the
achievement of better moisture absorbing and releasing properties
is still a problem to be solved.
[0011] In addition, although having moisture absorbing and
releasing properties as good as or better than those of natural
fibers, the core-sheath composite fibers described in WO '709, JP
'618 and JP '450 tend to suffer from thermal degradation of the
core component and hardening of the fibers as they undergo frequent
washing and drying in household type machines, causing the fabrics
to suffer from hardening of the texture, a decrease in durability,
or deterioration in moisture absorbing and releasing
performance.
SUMMARY
[0012] We thus provide: [0013] (1) A hygroscopic core-sheath
composite yarn including polyamide as the sheath polymer and a
polyether ester amide copolymer as the core polymer and
characterized by having a strength retention rate of 50% or more
after undergoing dry heat treatment at 150.degree. C. for 1 hour.
[0014] (2) A hygroscopic core-sheath composite yarn as set forth in
paragraph (1) having a .DELTA.MR value of 5.0% or more and a
.DELTA.MR retention rate of 70% or more after undergoing dry heat
treatment at 150.degree. C. for 1 hour. [0015] (3) A fabric
containing, at least partly, a hygroscopic core-sheath composite
yarn as set forth in either paragraph (1) or (2).
[0016] We provide a core-sheath composite yarn that is high in
hygroscopic performance, higher in comfortability than natural
fibers, and able to maintain a soft texture, high durability, and
moisture absorbing and releasing performance after undergoing
repeated washing and drying.
DETAILED DESCRIPTION
[0017] Our core-sheath composite yarn includes polyamide as the
sheath component and a polyether ester amide copolymer as the core
component.
[0018] The polyether ester amide copolymer is a block copolymer
having an ether bond, an ester bond, and an amide bond in one
molecular chain. More specifically, the block copolymer polymer
which can be produced by subjecting one, two, or more selected from
the group consisting of lactams, aminocarboxylic acids, and salts
of diamine and dicarboxylic acid, referred to polyamide component
(A), and a polyether ester component (B) formed of a dicarboxylic
acid and a poly(alkylene oxide) glycol to condensation
polymerization reaction.
[0019] Substances suitable as the polyamide component (A) include
lactams such as .epsilon.-caprolactam, dodecanolactam, and
undecanolactam; .omega.-aminocarboxylic acids such as aminocaproic
acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid; and
nylon salts of diamine-dicarboxylic acids that serve as precursors
of nylon 66, nylon 610, nylon 612 and the like, of which
.epsilon.-caprolactam is preferred as polyamide-forming
component.
[0020] The polyether ester component (B) is formed of a
dicarboxylic acid containing 4 to 20 carbon atoms and a
poly(alkylene oxide) glycol. Examples of the dicarboxylic acid
containing 4 to 20 carbon atoms include aliphatic dicarboxylic
acids such as succinic acid, glutaric acid, adipic acid, pimelic
acid, suberic acid, sebacic acid, and dodecanoic acid; aromatic
dicarboxylic acids such as terephthalic acid, isophthalic acid, and
2,6-naphthalene dicarboxylic acid; and alicyclic dicarboxylic acids
such as 1,4-cyclohexanedicarboxylic acid that may be used singly or
as a mixture of two or more thereof. Preferable dicarboxylic acids
include adipic acid, sebacic acid, dodecanoic acid, terephthalic
acid, and isophthalic acid. Examples of the poly(alkylene oxide)
glycol include polyethylene glycol, poly(1,2- or 1,3-propylene
oxide) glycol, poly(tetramethylene oxide) glycol, and
poly(hexamethylene oxide) glycol, of which polyethylene glycol is
preferable because of having high hygroscopic performance.
[0021] It is preferable for the poly(alkylene oxide) glycol to have
a number average molecular weight of 300 to 3,000, more preferably
500 to 2,000. A molecular weight of 300 or more is preferable
because scattering out of the system during condensation
polymerization reaction can be prevented to ensure the formation of
a fiber with stable hygroscopic performance. A molecular weight of
3,000 or less is preferable because the poly(alkylene oxide) glycol
can be dispersed uniformly in the polymer to ensure high
hygroscopic performance.
[0022] Regarding the component percentage of the polyether ester
component (B), it preferably accounts for 20% to 80% by mole of the
total quantity of the polyether ester amide copolymer. A percentage
of 20% or more is preferable because high hygroscopic performance
can be realized. On the other hand, a percentage of 80% or less is
preferable to ensure high dyed color fastness and little
hygroscopic performance deterioration by washing.
[0023] The component percentages of the polyamide and poly(alkylene
oxide) glycol are preferably 20%/80% to 80%/20% by mole. A
poly(alkylene oxide) glycol content of 20% or more is preferable
because high hygroscopic performance can be realized. On the other
hand, a poly(alkylene oxide) glycol preferably content of 80% or
less is preferable to ensure high dyed color fastness and little
hygroscopic performance deterioration by washing.
[0024] Commercially available products of such a polyether ester
amide copolymer include MH1657 and MV1074 manufactured by Arkema
K.K.
[0025] Examples of the polyamide used as the sheath component
include nylon 6, nylon 66, nylon 46, nylon 9, nylon 610, nylon 11,
nylon 12, and nylon 612; and copolymer polyamides containing, as a
copolymer component, a compound having a functional group that can
form an amide with the former such as laurolactam, sebacic acid,
terephthalic acid, isophthalic acid, and 5-sodium sulfoisophthalic
acid. In particular, nylon 6, nylon 11, nylon 12, nylon 610, and
nylon 612 are preferable from the viewpoint of yarn-making
performance because they are small in the difference in melting
point from the polyether ester amide copolymer, serving to depress
the thermal degradation of the polyether ester amide copolymer
during melting spinning. Of these, nylon 6 is particularly
preferable because of high dyeability.
[0026] It is essential for the core-sheath composite yarn to have a
strength retention rate of 50% or more and 100% or less after
undergoing dry heat treatment at 150.degree. C. for 1 hour. If it
is less than 50%, the raw threads will become hard and brittle and
a fabric test piece will decrease in durability and suffer breakage
or the like when subjected to repeated drying test in a household
washing and drying machine (hereinafter referred to as tumble
drying). It is preferably 60% or more and 100% or less. If it is in
this range, it will be possible to produce clothing that can
maintain durability after repeated tumble drying.
[0027] It is preferable for the core-sheath composite yarn to have
a tensile strength of 2.5 cN/dtex or more. It is more preferably
3.0 cN/dtex or more. If it is in this range, it will be possible to
produce clothing that are high enough in strength to serve for
practical clothing uses such as innerwear and sports apparel
applications.
[0028] It is essential for the core-sheath composite yarn to
maintain controlled humidity in clothing to ensure high
comfortability when they are worn. The degree of humidity control
is examined based on .DELTA.MR, which denotes the difference
between the hygroscopicity at 30.degree. C. and 90% RH, which
represent a typical temperature and humidity conditions in clothing
resulting from a light to medium degree of work or a light to
medium degree of exercise and that at 20.degree. C. and 65% RH,
which represent a typical outdoor air temperature and humidity
conditions. A larger .DELTA.MR value ensures a higher hygroscopic
performance and higher comfortability when the clothes are
worn.
[0029] It is preferable for the core-sheath composite yarn to have
a .DELTA.MR value of 5.0% or more. It is more preferably 7.0% or
more and still more preferably 10.0% or more. If it is in this
range, it will be possible to produce clothing that have reduced
stuffiness and stickiness when worn and have high
comfortability.
[0030] It is preferable for the core-sheath composite yarn to have
a .DELTA.MR retention rate of 70% or more and 100% or less after
undergoing dry heat treatment at 150.degree. C. for 1 hour. If it
is in this range, it will be possible to produce clothing that can
maintain moisture absorbing and releasing performance as well as
high comfortability after undergoing repeated tumble drying.
[0031] A polyether ester amide copolymer to be used in the core
contains both a hindered phenolic stabilizer, which is an
antioxidant to capture radicals, and a hindered amine based
stabilizer (hereinafter referred to as HALS type stabilizer) to
make it possible to provide a core-sheath composite yarn
characterized by depressed thermal degradation of the polyether
ester amide copolymer even after undergoing repeated tumble drying
to ensure a high durability and moisture absorbing and releasing
performance as well as a soft texture.
[0032] The polyether ester amide copolymer used in the core
contains poly(alkylene oxide) glycol, and when the poly(alkylene
oxide) glycol is heated, radicals will be generated from the
molecule and attack adjacent atoms to further generate radicals to
cause chain reaction, and the reaction heat will work to increase
the temperature up to as high as 200.degree. C. As the molecular
weight of the poly(alkylene oxide) glycol decreases, the molecular
chain will be heated more easily to generate more radicals and
generate more reaction heat.
[0033] The polyether ester amide copolymer contains a poly(alkylene
oxide) glycol having a relatively low number average molecular
weight of 300 to 3,000 and, accordingly, the polyether ester amide
copolymer tends to undergo thermal degradation easily through the
above mechanism, thus leading very easily to raw threads that are
hard and brittle and have an inferior hygroscopic performance.
[0034] To avoid this, a hindered phenolic stabilizer, which is an
antioxidant to capture radicals, is added to the polyether ester
amide copolymer contained in the core. However, the addition of a
hindered phenolic stabilizer alone will lead to progress of thermal
degradation of the polyether ester amide copolymer due to the heat
history in the spinning step (high temperature heating for melting
the polymer and thermal setting after stretching) and the heat
history in high-order processing steps (dyeing, thermal setting or
the like of fabric), resulting in a large decrease in the effective
component quantity of the antioxidant working to capture radicals
remaining at the stages of fabrics and clothing. As they
subsequently undergo repeated tumble drying, the polyether ester
amide copolymer will suffer from further thermal degradation and
the raw threads will become harder and more brittle and deteriorate
in hygroscopic performance. Thus, the texture will become harder
due to repeated washing and drying, leading to deterioration in
durability and moisture absorbing and releasing performance.
[0035] Therefore, if a HALS (hindered amine light stabilizer) type
stabilizer is used in combination to prevent a decrease in the
effective component quantity of the antioxidant that works to
capture radicals remaining in fabrics or clothing products, thermal
degradation of the hindered phenolic stabilizer will be depressed
to allow a soft texture, high durability, and moisture absorbing
and releasing performance to be maintained after repeated tumble
drying.
[0036] Regarding the quantity of the hindered phenolic stabilizer
to be added when producing the core-sheath composite yarn, it
preferably accounts for 1.0 wt % or more and 5.0 wt % or less
relative to the weight of the polyether ester amide copolymer in
the core. It more preferably accounts for 2 wt % or more and 4 wt %
or less. If it is 1.0 wt % or more, it will be possible to produce
raw threads that will not become hard or brittle or deteriorate in
hygroscopic performance after undergoing repeated tumble drying. If
it is 5.0 wt % or less, the yarn-making performance will be high
and yellowing of the raw threads will be reduced.
[0037] The quantity of the residual hindered phenolic stabilizer in
the core-sheath composite yarn is preferably 70% or more of the
quantity of the hindered phenolic stabilizer (relative to the
core-sheath composite yarn) added in the production process. It is
more preferably 80% or more. If it is in this range, it will be
possible to produce raw threads that will not become hard or
brittle or deteriorate in hygroscopic performance after undergoing
repeated tumble drying.
[0038] Regarding the quantity of the HALS type stabilizer to be
added when producing the core-sheath composite yarn, it preferably
accounts for 1.0 wt % or more and 5.0 wt % or less relative to the
weight of the polyether ester amide copolymer in the core. It more
preferably accounts for 1.5 wt % or more and 4.0 wt % or less. If
it is 1.0 wt % or more, it will be possible to depress the thermal
degradation of the hindered phenolic stabilizer used in
combination. If it is 5.0 wt % or less, the yarn-making performance
will be high and yellowing of raw threads will be reduced.
[0039] For the hindered phenolic stabilizer and HALS type
stabilizer, the 5% weight loss temperature during thermogravimetric
analysis is preferably 300.degree. C. or more. If it is 300.degree.
C. or more, the stabilizer itself will suffer little degradation
that may be caused by the heat history in the spinning step or the
heat history in high-order processing steps to allow a significant
effective component quantity of the antioxidant to be left to
capture radicals remaining in fabric and clothing products so that
the polyether ester amide copolymer will suffer little thermal
degradation after undergoing repeated tumble drying and serve to
maintain a soft texture and high durability and moisture absorbing
and releasing performance, and therefore it is preferable.
[0040] Examples of such a hindered phenolic stabilizer include, for
example, pentaery-thritoltetrakis
[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (IR1010),
(1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxyphenyl)
benzene (AO-330),
1,3,5-tris-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]
methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (IR3114), and
N,N'-hexamethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propane
amide] (IR1098).
[0041] Examples of such a HALS type stabilizer include, for
example, a polycondensate of dibutylamine-1,3,5-triazine,
N,N-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylene diamine,
and N-(2,2,6,6-tetramethyl-4-piperidyl)butyl amine
(CHIMASSORB2020FDL), 4,7,N,N'-tetrakis
[4,6-bis[butyl(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine--
2-yl]-4,7-diaza-decane-1,10-diamine (CHIMASSORB119),
poly[{6-(1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl)
((2,2,6,6-tetramethyl-4-piperidyl)imino) hexamethylene
((2,2,6,6-tetramethyl-4-piperidyl) imino (CHIMASSORB944).
[0042] The polyamide sheath component may contain, in the form of a
copolymer or a mixture, various additives such as, for example,
delustering agent, flame retardant, ultraviolet absorber, infrared
ray absorbent, crystal nucleating agent, fluorescent whitening
agent, antistatic agent, hygroscopic polymer, and carbon, as
required such that the total additive content is 0.001% to 10 wt %
of the total fiber quantity.
[0043] It is preferable for the core-sheath composite yarn to have
an elongation percentage of 35% or more. It is more preferably 40%
to 80%. If it is in this range, a high process passability will be
ensured for high-order steps such as weaving, knitting, and
false-twisting.
[0044] There are no specific limitations on the total fineness and
number of filaments in the core-sheath composite yarn, and the
resulting fabrics may have any desired cross-sectional shape to
meet their purposes. In view of its use as long fiber material for
clothing, multifilaments produced therefrom preferably have a total
fineness of 5 decitex or more and 235 decitex or less and contain 1
or more and 144 or less filaments. The cross section may preferably
be circular, triangle, flattened, Y-shaped, start-like, eccentric,
or pasted type.
[0045] The core-sheath composite yarn can be produced by a
generally known method such as melt-spinning and composite
spinning, and typical methods are described below.
[0046] For example, polyamide (the sheath component) and a
polyether ester amide copolymer (the core) are melted, weighed, and
transported by a gear pump separately, and then they are combined
by a common method into a composite flow having a core-sheath
structure and discharged from a spinneret to produce threads, which
are then cooled to room temperature by applying cooling air from a
cooling apparatus such as chimney, bundled while supplying oil from
an oil feeding apparatus, interlaced by a first fluid interlacing
nozzle apparatus, and transported on a take-up roller and a
stretching roller where the yarn is stretched according to the
ratio of circumferential speeds of the take-up roller and the
stretching roller. Subsequently, the yarn is heat-set by the heat
of the stretching roller and wound up by a winder (winding-up
apparatus).
[0047] In the spinning step, it is preferable for the spinning
temperature to be 240.degree. C. or more and 270.degree. C. or
less. A spinning temperature of 240.degree. C. or more is
preferable because the polyamide and polyether ester amide
copolymer will have a melt viscosity suitable for melt-spinning. A
temperature of 270.degree. C. or less is preferable because the
hindered phenolic stabilizer and the HALS type stabilizer can be
performed effectively without undergoing thermal decomposition,
thus serving to depress the thermal decomposition of the polyether
ester amide copolymer.
[0048] For the core-sheath composite yarn, it is necessary for the
core to account for 20 wt % to 80 wt % of the entire composite
yarn. It is more preferably 30 wt % to 70 wt %. If it is in this
range, it will be possible to stretch the polyamide in the sheath
to an appropriate degree. It will be also possible to achieve a
desired dyed color fastness and hygroscopic performance. If it is
less than 20 wt %, a sufficient hygroscopic performance may not be
achieved. If it is more than 80 wt %, on the other hand, cracking
of the fiber surface may occur easily due to swelling in a
hydrothermal atmosphere such as in the dyeing step, and in addition
the polyamide in the sheath may be stretched excessively to cause
thread breakage and fuzzing. For stable production of intended
fibers, spinning and stretching that can cause excessive tension
are not desirable because thread breakage and fuzzing may be
caused.
[0049] The sheath is preferably formed of polyamide chips having a
sulfuric acid relative viscosity of 2.3 or more and 3.3 or less. If
it is in this range, it will be possible to stretch the polyamide
in the sheath to an appropriate degree.
[0050] The polymer chips of the polyether ester amide copolymer
used in the core preferably has an orthochlorophenol relative
viscosity of 1.2 or more and 2.0 or less. An orthochlorophenol
relative viscosity of 1.2 or more is preferable because an optimum
stress will be applied to the sheath during spinning and
accordingly, the crystallization of the polyamide in the sheath
will be accelerated to ensure high strength.
[0051] Good methods for blending a hindered phenolic stabilizer or
a HALS type stabilizer with a polyether ester amide copolymer
include the dry blending method in which a hindered phenolic
stabilizer or a HALS type stabilizer is attached to chips of a
polyether ester amide copolymer and the master chip method in which
master chips of a polyether ester amide copolymer mixed with a high
concentration of a hindered phenolic stabilizer or HALS type
stabilizer are prepared first in a twin screw extruder or a single
screw extruder, followed by blending the master chips and polyether
ester amide copolymer chips in the spinning step. Use of the master
chips is preferable because a high concentration of a hindered
phenolic stabilizer or HALS type stabilizer can be dispersed
uniformly in the polymer.
[0052] The spinning conditions are preferably set up so that the
speed of the threads taken up on the take-up roller (spinning
speed) multiplied by the draw ratio, which is the ratio in
circumferential speed between the take-up roller and the stretching
roller, is 3,300 or more and 4,500 or less in the stretching step.
It is more preferably 3,300 or more and 4,000 or less. This value
represents the total quantity of stretching that the polymer
undergoes as it is discharged from the spinneret, accelerated from
the spinneret discharging linear speed to the circumferential speed
of the take-up roller, and pulled further from the circumferential
speed of the take-up roller to the circumferential speed of the
stretching roller. If it is in this range, it will be possible to
stretch the polyamide in the sheath to an appropriate degree. A
value of 3,300 or more is preferable because it ensures accelerated
crystallization of the polyamide in the sheath, leading to an
improved raw thread strength and heat resistance. A value of 4,500
or less is preferable because it ensures moderate crystallization
of the polyamide in the sheath, leading to a lower degree of thread
breakage and fuzzing in the yarn-making step.
[0053] The thermal setting temperature on the stretching roller is
preferably 110.degree. C. or more and 160.degree. C. or less. A
temperature of 110.degree. C. or more is preferable because it
ensures accelerated crystallization of the nylon in the sheath,
leading to improvement in strength and depression of tight winding
by the drum. A temperature of 160.degree. C. or less is preferable
because it ensures depression of the thermal decomposition of the
hindered phenolic stabilizer.
[0054] For the oil feeding step, the spinning oil solution fed by
the oil feeding apparatus is preferably a non-aqueous oil solution.
The polyether ester amide copolymer in the core is a highly
hygroscopic polymer with a .DELTA.MR value of 10% or more and,
accordingly, the use of a non-aqueous oil solution is preferable
because it allows gradual absorption of moisture from air, thus
preventing significant swelling to ensure stable winding-up.
[0055] The core-sheath composite yarn has high hygroscopic
performance and, accordingly, it is preferred for production of
clothing. The intended fabric may be in the form of woven fabric,
knitted fabric, nonwoven fabric and the like, as required to meet
particular purposes. As described above, a larger .DELTA.MR value
ensures a higher hygroscopic performance and higher comfortability
when the fabric is worn. In a fabric at least partly containing the
core-sheath composite yarn, therefore, clothing with high
comfortability can be produced by controlling the mixing rate of
the core-sheath composite yarn to adjust the .DELTA.MR value to
5.0% or more. Examples of such clothing include innerwear,
sportswear, and other various clothing products.
EXAMPLES
[0056] Our yarns and fabrics are now described in more detail with
reference to examples. The methods used for the measurement of
characteristic values are as described below.
(1) Sulfuric Acid Relative Viscosity
[0057] First, 0.25 g of a specimen was dissolved in sulfuric acid
with a concentration of 98 wt % such that it would account for 1 g
in 100 ml, and the efflux time (T1) through an Ostwald type
viscometer was measured at 25.degree. C. Subsequently, the efflux
time (T2) of the sulfuric acid with a concentration of 98 wt %
alone was measured. The ratio of T1 to T2, i.e., T1/T2, was adopted
as sulfuric acid relative viscosity.
(2) Orthochlorophenol Relative Viscosity
[0058] First, 0.5 g of a specimen was dissolved in
orthochlorophenol such that it accounts for 1 g in 100 ml, and the
efflux time (T1) through an Ostwald type viscometer was measured at
25.degree. C. Subsequently, the efflux time (T2) of the
orthochlorophenol alone was measured. The ratio of T1 to T2, i.e.,
T1/T2, was adopted as sulfuric acid relative viscosity.
(3) Fineness
[0059] A fiber specimen was set on a sizing reel with a
circumference of 1.125 m and rotated 200 times to prepare a loop
like hank, and then the hank was dried in a hot air drier
(105.+-.2.degree. C. for 60 minutes) and weighed in a balance,
followed by multiplying the weight by an official moisture regain
to calculate the fineness. The official moisture regain of the
core-sheath composite yarn was assumed to be 4.5%.
(4) Strength and Elongation Percentage
[0060] A fiber specimen was subjected to measurement using TENSILON
(registered trademark) UCT-100 manufactured by Orientec Co., Ltd.
under the constant stretching rate conditions specified in JIS
L1013 (Chemical fiber filament test method, 2010). The elongation
percentage was determined from the elongation at the maximum
strength point on the tensile strength vs. elongation curve. The
strength is calculated by dividing the maximum strength by the
fineness. For strength and elongation percentage, ten measurements
were taken and their average was adopted.
(5) Strength After Dry Heat Treatment
[0061] A fiber specimen was set on a sizing reel with a
circumference of 1.125 m and rotated 200 times to prepare a loop
like hank, and then the hank was heat-treated in a hot air drier
(150.+-.2.degree. C. for 60 minutes), followed by calculating the
strength of the dry-heat-treated specimen as described in paragraph
(4).
(6) Strength Retention Rate After Dry Heat Treatment
[0062] To represent the difference in strength between before and
after the dry heat treatment, the strength retention rate of a
heat-treated specimen was calculated by the equation blow:
(strength after dry heat treatment/strength before dry heat
treatment).times.100.
(7) 5% Weight Loss Temperature
[0063] A thermogravimetric analyzer (TGA7, manufactured by Perkin
Elmer) was used for the measurement. In a nitrogen atmosphere, a 10
mg specimen was heated from 30.degree. C. to 400.degree. C. at a
heating rate of 10.degree. C./min, followed by calculating the
temperature at the point of 5% weight reduction.
(8) Quantity of Residual Hindered Phenolic Stabilizer (Relative to
Core-Sheath Composite Yarn)
A. Preparation of Standard Solution
[0064] In a 20 mL measuring flask, 0.02 g of a hindered phenolic
stabilizer was weighed out and 2 mL of chloroform was added to
dissolve it, followed by adding tetrahydrofuran (THF) to volume
(undiluted standard solution: about 1,000 .mu.g/mL). The original
standard solution was diluted appropriately with acetonitrile to
prepare a standard solution.
B. Preparation of Additive Standard Solution
[0065] In a 10 mL measuring flask, 0.01 g of a hindered phenolic
stabilizer was weighed out and 2 mL of chloroform was added to
dissolve it, followed by adding tetrahydrofuran (THF) to volume
(standard solution for adding hindered phenolic stabilizer: about
1,000 .mu.g/mL).
C. Preparation of Specimen Solution (n=2) [0066] a. A 0.1 g portion
of a fiber specimen was dissolved in 1 mL of hexafluoroisopropanol
(HFIP) and 2 mL of chloroform was added and dissolved. [0067] b. A
40 mL volume of tetrahydrofuran (THF) was added gradually (the
polymer was insolubilized). [0068] c. Filtration was performed
through a paper filter and the solution obtained was condensed and
exsiccated. [0069] d. A 1 mL volume of HFIP was added to the
residue to dissolve it and the resulting solution was transferred
to a 10 mL measuring flask. [0070] e. The container used above was
washed with THF and the washings were added to 10 mL. [0071] f.
Filtration was performed through a PTFE membrane filter with a pore
size of 0.45 .mu.m and the resulting solution was adopted as
specimen solution. Pre-treatment was performed without using a
specimen to provide a blank test solution.
D. LC/UV and LC/ELSD Analysis Conditions
[0071] [0072] LC system: LC10A (manufactured by Shimadzu
Corporation) [0073] Column: Asahipak ODP-40 4D 4.6.times.150 mm, 4
.mu.m (manufactured by Showa Denko K.K.) [0074] Mobile phase:
A--[28% aqueous ammonia/methanol=9/1,000]/water=1/1 [0075] B--0.1%
triethyl amine THF solution [0076] Time program
TABLE-US-00001 [0076] 0 to 3 min B: 50% 3 to 10 min B: 50% -->
70% 10 to 15 min B: 70% --> 90% 15 to 20 min B: 90% -->
100%
[0077] Flow rate: 1.0 mL/min [0078] Injection rate: 20 .mu.L [0079]
Column temperature: 45.degree. C. [0080] Detection: hindered
phenolic stabilizer UV 280 nm
(9) Preparation of Cylindrical Knitted Fabric
[0081] A cylindrical knitted fabric sample was produced using a
cylindrical knitting machine while adjusting the density to 50. If
the fiber is low in the corrected weight based fineness, yarn
doubling is performed appropriately so that the fiber fed to the
cylindrical knitting machine would have a total fineness of 50 to
100 decitex. If the total fineness is more than 100 decitex, a
single yarn was fed to the cylindrical knitting machine and the
density was adjusted to 50 as above.
(10) .DELTA.MR
[0082] About 1 to 2 g of the cylindrical knitted fabric was weighed
out in a weighing bottle, dried by storage at 110.degree. C. for 2
hours, and weighed (W0). Subsequently, the target substance was
maintained at 20.degree. C. and a relative humidity of 65% for 24
hours and then weighed (W65). This was maintained at 30.degree. C.
and a relative humidity of 90% for 24 hours and then weighed (W90).
Calculations were made by the equations below:
MR65=[(W65-W0)/W0].times.100% (1)
MR90=[(W90-W0)/W0].times.100% (2)
.DELTA.MR=MR90-MR65 (3).
(11) .DELTA.MR After Dry Heat Treatment
[0083] The cylindrical knitted fabric sample was heat-treated
(150.+-.2.degree. C. for 60 minutes) in a hot air drier and then
its moisture absorbing and releasing properties were measured,
followed by making calculations.
(12) .DELTA.MR Retention Rate After Dry Heat Treatment
[0084] To represent the difference in .DELTA.MR between before and
after the dry heat treatment, the .DELTA.MR retention rate of a
dry-heat-treated specimen was calculated by the equation below:
(.DELTA.MR after dry heat treatment/.DELTA.MR before dry heat
treatment).times.100.
(13) Tumble Drying
[0085] The cylindrical knitted fabric sample was dried at a
temperature of 80.degree. C. for 1 hour in a type-A1 tumble drying
machine as specified in JIS L1930 (2014, household washing test
method) Appendix G. This procedure was repeated 10 times.
(14) Texture Evaluation
[0086] The texture of the tumble-dried cylindrical knitted fabric
sample was evaluated according to the four stage criterion given
below. A specimen rated as A or higher was assumed to be
acceptable. [0087] S: The texture is just as soft as before tumble
drying. [0088] A: The texture is nearly as soft as before tumble
drying. [0089] B: The texture is a little harder than before tumble
drying. [0090] C: The texture is significantly harder and stiffer
than before tumble drying.
(15) Durability Evaluation
[0091] The durability of a tumble-dried cylindrical knitted fabric
sample was evaluated according to Method A (Muhlen type method)
specified in "8.18 Bursting strength" of JIS L1096 (2010, Fabric
test method for woven fabrics and knitted fabrics). A specimen
rated as A or higher was assumed to be acceptable. [0092] S: 200
kPa or more [0093] A: 150 kPa or more and less than 200 kPa [0094]
C: less than 150 kPa
(16) Hygroscopicity Retention Property
[0095] The value of .DELTA.MR, which is defined in paragraph (10),
of a cylindrical knitted fabric sample was measured before and
after tumble drying, followed by calculating the retention rate. A
sample rated as A or higher was assumed to be acceptable. [0096] S:
80% or more [0097] A: 70% or more and less than 80% [0098] C: less
than 70%
Example 1
[0099] A polyether ester amide copolymer containing nylon 6 as
polyamide component and polyethylene glycol with a molecular weight
of 1,500 as polyether component with a molar ratio of 24% to 76%
between nylon 6 and polyethylene glycol (MH1657, manufactured by
Arkema K.K., orthochlorophenol relative viscosity 1.69) was
adopted, and chips of the polyether ester amide copolymer used as
core material. First, master chips prepared by adding a hindered
phenolic stabilizer (IR1010, manufactured by BASF, 5% weight loss
temperature 351.degree. C.) and a HALS type stabilizer
(CHIMASSORB2020FDL, manufactured by BASF, 5% weight loss
temperature 404.degree. C.) to high concentrations to the polyether
ester amide copolymer and chips of the polyether ester amide
copolymer were blended in a twin screw extruder so that the
hindered phenolic stabilizer (IR1010) and HALS type stabilizer
(CHIMASSORB2020FDL) would account for 2.0 wt %/2.0 wt %,
respectively, of the core.
[0100] As the polyamide component, chips of nylon 6 with a sulfuric
acid relative viscosity of 2.71 were used in the sheath.
[0101] The polyether ester amide copolymer adopted as core
component and the nylon 6 adopted as sheath component were melted
at a spinning temperature of 260.degree. C. and spun through a
spinneret designed for concentric circular core-sheath composite
yarn at a core/sheath ratio (wt %) of 30/70. The rotating speed of
the gear pump was controlled to produce a core-sheath composite
yarn having a total fineness of 56 dtex and the threads were cooled
and solidified in a thread cooling apparatus, fed with oil from a
non-aqueous oil solution feeding apparatus, interlaced in a first
fluid interlacing nozzle apparatus, stretched by a take-up roller
(first roller) having a circumferential speed of 2,405 m/min and a
stretching roller (second roller) having a circumferential speed of
3,608 m/min, thermally set by the stretching roller at 150.degree.
C., and wound up at a speed of 3,500 m/min to provide a 56-decitex,
24-filament core-sheath composite yarn. Physical properties of the
resulting fiber are shown in Table 1.
[0102] For the resulting core-sheath composite yarn, the proportion
of the residual hindered phenolic stabilizer was 88%, and the
strength retention rate after dry heat treatment and the .DELTA.MR
retention rate after dry heat treatment were 65% and 75%,
respectively. After undergoing repeated tumble drying, the raw
threads in the resulting core-sheath composite yarn hardly became
hard or brittle and maintained a soft texture and a high durability
and moisture absorbing and releasing performance.
Example 2
[0103] Except for adjusting the spinning temperature to 270.degree.
C., the same procedure as in Example 1 was carried out to provide a
56-decitex, 24-filament core-sheath composite yarn. Physical
properties of the resulting fiber are shown in Table 1.
[0104] For the resulting core-sheath composite yarn, the proportion
of the residual hindered phenolic stabilizer was 75%, and the
strength retention rate after dry heat treatment and the .DELTA.MR
retention rate after dry heat treatment were 60% and 72%,
respectively.
Example 3
[0105] Except for adjusting the spinning temperature to 240.degree.
C., the same procedure as in Example 1 was carried out to provide a
56-decitex, 24-filament core-sheath composite yarn. Physical
properties of the resulting fiber are shown in Table 1.
[0106] The proportion of the residual hindered phenolic stabilizer
in the resulting core-sheath composite yarn was a high 93%, and the
strength retention rate after heat treatment and the .DELTA.MR
retention rate after heat treatment were high 70% and 77%,
respectively.
Example 4
[0107] Except for adjusting the stretching roller temperature to
120.degree. C., the same procedure as in Example 1 was carried out
to provide a 56-decitex, 24-filament core-sheath composite yarn.
Physical properties of the resulting fiber are shown in Table
1.
[0108] The proportion of the residual hindered phenolic stabilizer
in the resulting core-sheath composite yarn was a high 90%, and the
strength retention rate after heat treatment and the .DELTA.MR
retention rate after heat treatment were high 67% and 77%,
respectively.
Example 5
[0109] Except for performing the spinning at a core/sheath ratio of
50/50 (parts by weight), the same procedure as in Example 1 was
carried out to provide a 56-decitex, 24-filament core-sheath
composite yarn. Physical properties of the resulting fiber are
shown in Table 1.
[0110] The proportion of the residual hindered phenolic stabilizer
in the resulting core-sheath composite yarn was a high 85%, and the
strength retention rate after heat treatment and the .DELTA.MR
retention rate after heat treatment were high 63% and 72%,
respectively.
TABLE-US-00002 TABLE 1 Example 1 Example 2 Example 3 Example 4
Example 5 Core component polymer polyether ester polyether ester
polyether ester polyether ester polyether ester amide copolymer
amide copolymer amide copolymer amide copolymer amide copolymer
relative viscosity 1.69 1.69 1.69 1.69 1.69 Sheath component
polymer nylon 6 nylon 6 nylon 6 nylon 6 nylon 6 relative viscosity
2.71 2.71 2.71 2.71 2.71 Core-sheath ratio core/sheath 30/70 30/70
30/70 30/70 50/50 Hindered phenolic type IR1010 IR1010 IR1010
IR1010 IR1010 stabilizer content (wt %) 2.00 2.00 2.00 2.00 2.00 5%
weight loss 351 351 351 351 351 temperature (.degree. C.) HALS type
stabilizer type CHIMASSROB CHIMASSROB CHIMASSROB CHIMASSROB
CHIMASSROB 2020FDL 2020FDL 2020FDL 2020FDL 2020FDL content (wt %)
2.00 2.00 2.00 2.00 2.00 5% weight loss 404 404 404 404 404
temperature (.degree. C.) Yarn-making conditions spinning
temperature (.degree. C.) 260 270 240 260 260 take-up speed (m/min)
2405 2405 2405 2405 2405 draw ratio 1.5 1.5 1.5 1.5 1.5 product
3608 3608 3608 3608 3608 thermal setting 150 150 150 120 150
temperature (.degree. C.) Physical properties of fineness (dtex) 56
56 56 56 56 raw thread elongation percentage (%) 50 50 50 50 48
proportion of 88 75 93 90 85 residual hindered phenolic stabilizer
(%) Strength retention strength (cN/dtex) 3.5 3.6 3.3 3.3 3.2
strength after 2.3 2.2 2.3 2.2 2.0 heat treatment (cN/dtex)
retention rate (%) 65 60 70 67 63 Hygroscopic .DELTA.MR(%) 7.5 7.2
7.7 7.5 11.7 performance retention .DELTA.MR after 5.6 5.2 5.9 5.8
8.4 heat treatment (%) retention rate (%) 75 72 77 77 72 Evaluation
of cylindrical texture A A S A A knitted fabric after durability S
S S S S tumble drying hygroscopicity retention A A A A A
Example 6
[0111] Except for performing the spinning step at a core/sheath
ratio of 70/30 (parts by weight), the same procedure as in Example
1 was carried out to provide a 56-decitex, 24-filament core-sheath
composite yarn. Physical properties of the resulting fiber are
shown in Table 2.
[0112] The proportion of the residual hindered phenolic stabilizer
in the resulting core-sheath composite yarn was a high 83%, and the
strength retention rate after heat treatment and the .DELTA.MR
retention rate after heat treatment were high 60% and 70%,
respectively.
Example 7
[0113] Except for adjusting the hindered phenolic stabilizer
(IR1010) and HALS type stabilizer (CHIMASSORB2020FDL) to 3.0 wt %
and 2.0 wt %, respectively, relative to the weight of the core, the
same procedure as in Example 1 was carried out to provide a
56-decitex, 24-filament core-sheath composite yarn. Physical
properties of the resulting fiber are shown in Table 2.
[0114] The proportion of the residual hindered phenolic stabilizer
in the resulting core-sheath composite yarn was a high 86%, and the
strength retention rate after heat treatment and the .DELTA.MR
retention rate after heat treatment were high 70% and 78%,
respectively.
Example 8
[0115] Except for adjusting the hindered phenolic stabilizer
(IR1010) and HALS type stabilizer (CHIMASSORB2020FDL) to 3.0 wt %
and 3 wt %, respectively, relative to the weight of the core, the
same procedure as in Example 1 was carried out to provide a
56-decitex, 24-filament core-sheath composite yarn. Physical
properties of the resulting fiber are shown in Table 2.
[0116] The proportion of the residual hindered phenolic stabilizer
in the resulting core-sheath composite yarn was a high 90%, and the
strength retention rate after heat treatment and the .DELTA.MR
retention rate after heat treatment were high 75% and 80%,
respectively.
Example 9
[0117] Except for adjusting the hindered phenolic stabilizer
(IR1010) and HALS type stabilizer (CHIMASSORB2020FDL) to 4 wt % and
4 wt %, respectively, relative to the weight of the core, the same
procedure as in Example 1 was carried out to provide a 56-decitex,
24-filament core-sheath composite yarn. Physical properties of the
resulting fiber are shown in Table 2.
[0118] The proportion of the residual hindered phenolic stabilizer
in the resulting core-sheath composite yarn was a high 93%, and the
strength retention rate after heat treatment and the .DELTA.MR
retention rate after heat treatment were high 80% and 85%,
respectively.
Example 10
[0119] Except for adjusting the hindered phenolic stabilizer
(IR1010) and HALS type stabilizer (CHIMASSORB2020FDL) to 1 wt % and
1 wt %, respectively, relative to the weight of the core, the same
procedure as in Example 1 was carried out to provide a 56-decitex,
24-filament core-sheath composite yarn. Physical properties of the
resulting fiber are shown in Table 2.
[0120] The proportion of the residual hindered phenolic stabilizer
in the resulting core-sheath composite yarn was a high 75%, and the
strength retention rate after heat treatment and the .DELTA.MR
retention rate after heat treatment were high 55% and 70%,
respectively.
TABLE-US-00003 TABLE 2 Example 6 Example 7 Example 8 Example 9
Example 10 Core component polymer polyether ester polyether ester
polyether ester polyether ester polyether ester amide copolymer
amide copolymer amide copolymer amide copolymer amide copolymer
relative viscosity 1.69 1.69 1.69 1.69 1.69 Sheath component
polymer nylon 6 nylon 6 nylon 6 nylon 6 nylon 6 relative viscosity
2.71 2.71 2.71 2.71 2.71 Core-sheath ratio core/sheath 70/30 30/70
30/70 30/70 30/70 Hindered phenolic type IR1010 IR1010 IR1010
IR1010 IR1010 stabilizer content (wt %) 2.00 3.00 3.00 4.00 1.00 5%
weight loss 351 351 351 351 351 temperature (.degree. C.) HALS type
stabilizer type CHIMASSROB CHIMASSROB CHIMASSROB CHIMASSROB
CHIMASSROB 2020FDL 2020FDL 2020FDL 2020FDL 2020FDL content (wt %)
2.00 2.00 3.00 4.00 1.00 5% weight loss 404 404 404 404 404
temperature (.degree. C.) Yarn-making conditions spinning
temperature (.degree. C.) 260 260 260 260 260 take-up speed (m/min)
2405 2405 2405 2405 2405 draw ratio 1.5 1.5 1.5 1.5 1.5 product
3608 3608 3608 3608 3608 thermal setting 150 150 150 150 150
temperature (.degree. C.) Physical properties of fineness (dtex) 56
56 56 56 56 raw thread elongation percentage (%) 48 52 47 47 48
proportion of 83 86 90 93 75 residual hindered phenolic stabilizer
(%) Strength retention strength (cN/dtex) 3.6 3.6 3.5 3.2 3.4
strength after 2.2 2.5 2.8 2.6 1.9 heat treatment (cN/dtex)
retention rate (%) 60 70 75 80 55 Hygroscopic .DELTA.MR(%) 15.2 7.7
7.9 8.0 7.1 performance retention .DELTA.MR after 10.6 6.0 6.3 6.8
5.0 heat treatment (%) retention rate (%) 70 78 80 85 70 Evaluation
of cylindrical texture A S S S A knitted fabric after durability S
S S S A tumble drying hygroscopicity retention A A S S A
Comparative Example 1
[0121] Except for omitting the addition of a hindered phenolic
stabilizer and a HALS type stabilizer and adjusting the strength
retention rate after dry heat treatment to 30%, the same procedure
as in Example 1 was carried out to provide a 56-decitex,
24-filament core-sheath composite yarn. Physical properties of the
resulting fiber are shown in Table 3.
[0122] The resulting core-sheath composite yarn had a .DELTA.MR
retention rate after dry heat treatment of 50%. After undergoing
repeated tumble drying, the raw threads in the resulting
core-sheath composite yarn were found to be hard or brittle and
have a stiff texture and an inferior durability.
Comparative Example 2
[0123] Except for omitting the addition of a HALS type stabilizer
(CHIMASSORB2020FDL) and adjusting the strength retention rate after
dry heat treatment to 40%, the same procedure as in Example 1 was
carried out to provide a 56-decitex, 24-filament core-sheath
composite yarn. Physical properties of the resulting fiber are
shown in Table 3.
[0124] The proportion of the residual hindered phenolic stabilizer
in the resulting core-sheath composite yarn was a low 40%, and the
.DELTA.MR retention rate after heat treatment was 55%. After
undergoing repeated tumble drying, the raw threads in the resulting
core-sheath composite yarn were found to be hard or brittle and
have a stiff texture and an inferior durability. In addition, the
hygroscopic performance deteriorated as a result of thermal
degradation of the polyethylene glycol component contained in the
polyether ester amide copolymer.
Comparative Example 3
[0125] Except for omitting the addition of a hindered phenolic
stabilizer (IR1010) and adjusting the strength retention rate after
dry heat treatment to 33%, the same procedure as in Example 1 was
carried out to provide a 56-decitex, 24-filament core-sheath
composite yarn. Physical properties of the resulting fiber are
shown in Table 3.
[0126] The resulting core-sheath composite yarn had a .DELTA.MR
retention rate after heat treatment of 52%. After undergoing
repeated tumble drying, the raw threads in the resulting
core-sheath composite yarn were found to be hard or brittle and
have a stiff texture and an inferior durability. In addition, the
hygroscopic performance deteriorated as a result of thermal
degradation of the polyethylene glycol component contained in the
polyether ester amide copolymer.
Comparative Example 4
[0127] Except for adjusting the hindered phenolic stabilizer
(IR1010) and HALS type stabilizer (CHIMASSORB2020FDL) to 0.5 wt %
and 0.5 wt %, respectively, relative to the weight of the core and
adjusting the strength retention rate after dry heat treatment to
45%, the same procedure as in Example 1 was carried out to provide
a 56-decitex, 24-filament core-sheath composite yarn. Physical
properties of the resulting fiber are shown in Table 3.
[0128] The proportion of the residual hindered phenolic stabilizer
in the resulting core-sheath composite yarn was a low 60%, and the
.DELTA.MR retention rate after heat treatment was 65%. After
undergoing repeated tumble drying, the raw threads in the resulting
core-sheath composite yarn were found to be hard or brittle and
have a stiff texture and an inferior durability. In addition, the
hygroscopic performance deteriorated as a result of thermal
degradation of the polyethylene glycol component contained in the
polyether ester amide copolymer.
Comparative Example 5
[0129] Except for using a hindered phenolic stabilizer with a 5%
weight loss temperature of 223.degree. C. (IR1135, manufactured by
BASF) and adjusting the strength retention rate after dry heat
treatment to 40%, the same procedure as in Example 1 was carried
out to provide a 56-decitex, 24-filament core-sheath composite
yarn. Physical properties of the resulting fiber are shown in Table
3.
[0130] For the resulting core-sheath composite yarn, the proportion
of the residual hindered phenolic stabilizer was 50% and the
.DELTA.MR retention rate after dry heat treatment was 60%. After
undergoing repeated tumble drying, the raw threads in the resulting
core-sheath composite yarn were found to be hard or brittle and
have a stiff texture and an inferior durability. In addition, the
hygroscopic performance deteriorated as a result of thermal
degradation of the polyethylene glycol component contained in the
polyether ester amide copolymer.
Comparative Example 6
[0131] Except for using a HALS type stabilizer with a 5% weight
loss temperature of 275.degree. C. (Adeka Stab LA-81, manufactured
by Adeka Corporation) and adjusting the strength retention rate
after dry heat treatment to 45%, the same procedure as in Example 1
was carried out to provide a 56-decitex, 24-filament core-sheath
composite yarn. Physical properties of the resulting fiber are
shown in Table 3.
[0132] For the resulting core-sheath composite yarn, the proportion
of the residual hindered phenolic stabilizer was 63% and the
.DELTA.MR retention rate after dry heat treatment was 65%. After
undergoing repeated tumble drying, the raw threads in the resulting
core-sheath composite yarn were found to be hard or brittle and
have a stiff texture and an inferior durability. In addition, the
hygroscopic performance deteriorated as a result of thermal
degradation of the polyethylene glycol component contained in the
polyether ester amide copolymer.
Comparative Example 7
[0133] Except for replacing the hindered phenolic stabilizer with a
phosphorus-based antioxidant (Adeka Stab PEP-36, manufactured by
Adeka Corporation, 5% weight loss temperature 316.degree. C.) and
adjusting the strength retention rate after dry heat treatment to
45%, the same procedure as in Example 1 was carried out to provide
a 56-decitex, 24-filament core-sheath composite yarn.
[0134] The resulting fiber had a fineness of 56 decitex, an
elongation percentage of 50%, a strength of 3.0 cN/dtex, a
.DELTA.MR value of 6.7%, and a .DELTA.MR retention rate after dry
heat treatment of 60%.
[0135] After undergoing repeated tumble drying, the raw threads in
the resulting core-sheath composite yarn were found to be hard or
brittle and have a stiff texture and an inferior durability and
hygroscopicity retention property. Thus, the phosphorus-based
antioxidant did not work effectively.
TABLE-US-00004 TABLE 3 Comparative Comparative Comparative
Comparative Example 1 Example 2 Example 3 Example 4 Core component
polymer polyether ester polyether ester polyether ester polyether
ester amide amide amide amide copolymer copolymer copolymer
copolymer relative viscosity 1.69 1.69 1.69 1.69 Sheath polymer
nylon 6 nylon 6 nylon 6 nylon 6 component relative viscosity 2.71
2.71 2.71 2.71 Core-sheath ratio core/sheath 30/70 30/70 30/70
30/70 Hindered phenolic type IR1010 IR1010 IR1010 IR1010 stabilizer
content (wt %) 0 2.00 0 0.50 5% weight loss temperature (.degree.
C.) 351 351 351 351 HALS type type CHIMASSROB CHIMASSROB CHIMASSROB
CHIMASSROB stabilizer 2020FDL 2020FDL 2020FDL 2020FDL content (wt
%) 0 0 2.00 0.50 5% weight loss temperature (.degree. C.) 404 404
404 404 Yarn-making spinning temperature (.degree. C.) 260 260 260
260 conditions take-up speed (m/min) 2405 2405 2405 2405 draw ratio
1.5 1.5 1.5 1.5 product 3608 3608 3608 3608 thermal setting
temperature (.degree. C.) 150 150 150 150 Physical fineness (dtex)
56 56 56 56 properties of raw elongation percentage (%) 43 45 44 48
thread proportion of residual hindered 0 40 0 60 phenolic
stabilizer (%) Strength retention strength (cN/dtex) 3.0 3.2 3.2
3.4 strength after 0.9 1.3 1.1 1.5 heat treatment (cN/dtex)
retention rate (%) 30 40 33 45 Hygroscopic .DELTA.MR (%) 6.7 7.0
6.9 7.2 performance .DELTA.MR after 3.4 3.9 3.6 4.7 retention heat
treatment (%) retention rate (%) 50 55 52 65 Evaluation of texture
C C C B cylindrical knitted durability C C C C fabric after tumble
hygroscopicity retention C C C C drying Comparative Comparative
Comparative Example 5 Example 6 Example 7 Core component polymer
polyether ester polyether ester polyether ester amide amide amide
copolymer copolymer copolymer relative viscosity 1.69 1.69 1.69
Sheath polymer nylon 6 nylon 6 nylon 6 component relative viscosity
2.71 2.71 2.71 Core-sheath ratio core/sheath 30/70 30/70 30/70
Hindered phenolic type IR1135 IR1010 Adeka Stab stabilizer PEP-36
content (wt %) 2.00 2.00 2.00 5% weight loss temperature (.degree.
C.) 223 351 316 HALS type type CHIMASSROB Adeka Stab CHIMASSROB
stabilizer 2020FDL LA-81 2020FDL content (wt %) 2.00 2.00 2.00 5%
weight loss temperature (.degree. C.) 404 275 404 Yarn-making
spinning temperature (.degree. C.) 260 260 260 conditions take-up
speed (m/min) 2405 2405 2405 draw ratio 1.5 1.5 1.5 product 3608
3608 3608 thermal setting temperature (.degree. C.) 150 150 150
Physical fineness (dtex) 56 56 56 properties of raw elongation
percentage (%) 50 50 50 thread proportion of residual hindered 50
63 -- phenolic stabilizer (%) Strength retention strength (cN/dtex)
3.2 3.1 3.0 strength after 1.3 1.4 1.4 heat treatment (cN/dtex)
retention rate (%) 40 45 45 Hygroscopic .DELTA.MR (%) 6.8 6.6 6.7
performance .DELTA.MR after 4.1 4.3 4.0 retention heat treatment
(%) retention rate (%) 60 65 60 Evaluation of texture C B B
cylindrical knitted durability C C C fabric after tumble
hygroscopicity retention C C C drying
INDUSTRIAL APPLICABILITY
[0136] We provide a core-sheath composite yarn high in hygroscopic
performance, higher in comfortability than natural fibers, and able
to maintain a soft texture, high durability, and moisture absorbing
and releasing performance after undergoing repeated washing and
drying.
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