Note: Descriptions are shown in the official language in which they were submitted.
CA 02580530 2007-03-14
. =
-
- 1 -
CRIMPED FILAMENT-CONTAINING WOVEN OR KNITTED FABRIC WITH
DECREASING AIR SPACE UPON WETTING WITH WATER, PROCESS FOR
PRODUCING THE SAME AND TEXTILE PRODUCTS THEREFROM
FIELD OF THE INVENTION
The present invention relates to a crimped filament-
containing woven or knitted fabric with a decreased air
space upon wetting with water, to a process for producing
it, and to textile products obtained therefrom. More
specifically, the invention relates to a woven or knitted
fabric with a decreased air space upon wetting with water
and an increasing air space upon drying, as well as to a
process for producing it and to textile products obtained
therefrom.
BACKGROUND ART
Fabrics that undergo reversible change in air space
by water wetting and drying are known as moisture-
sensitive fabrics, and such moisture-sensitive fabrics
having various structures have recently been proposed.
For example, Japanese Unexamined Patent Publication
No. 2003-41462 (Patent document 1) discloses an air-
permeable self-adjusting woven/knitted fabric comprising
crimped conjugated fibers obtained by heat treatment of
conjugated fibers made of a polyester resin component and
a polyamide resin component bonded in a side-by-side
fashion, to produce crimps. In this woven/knitted
fabric, the percentage of crimp of the side-by-side
crimped conjugated fibers is reduced by water wetting,
thereby increasing the air space of the woven/knitted
fabric and improving the air permeability.
When swimming wear or sportswear manufactured from
ordinary woven/knitted fabrics made of synthetic or
natural fibers is wetted with water, the light
permeability often increases and causes the inner side to
become visible, and therefore a solution to this problem
T T
CA 02580530 2007-03-14
4, '
- 2 -
has been desired. Demand also exists for provision of
woven/knitted fabrics with reduced air space and improved
waterproof properties in response to water wetting. Yet,
woven and knitted fabrics that exhibit improved air
permeability (increased air space) by water wetting have
reduced waterproof properties in response to water
wetting, and therefore cannot meet such demands.
Patent document 1: Japanese Unexamined Patent
Publication No. 2003-41462
DISCLOSURE OF THE INVENTION
It is an object of the present invention to provide
a crimped filament-containing woven or knitted fabric
with a lower air space when wetted with water compared to
its dry state, and an increased air space upon drying, as
well as a process for producing it and to textile
products obtained therefrom.
This object can be achieved by the woven/knitted
fabric of the invention, the process for producing it and
its textile products according to the invention.
The crimped filament-containing woven or knitted
fabric of the invention is a woven or knitted fabric
comprising crimped filaments A whose percentage of crimp
decreases upon wetting with water, and filaments B
composed of at least one type selected from among
filaments with no crimps and crimped filaments which
undergo substantially no change in percentage of crimp
upon wetting with water,
characterized in that the percentage of crimp DCf(%)
of a sample of dry crimped filaments A prepared by
allowing a sample of the crimped filaments A taken from
the woven or knitted fabric to stand for 24 hours in an
environment at a temperature of 20 C, 65% RH, and the
percentage of crimp HCf(%) of a sample of the water wetted
crimped filaments A prepared by immersing a sample of the
crimped filaments A in water at a temperature of 20 C for
2 hours, lifting it out from the water, sandwiching the
CA 02580530 2007-03-14
3 -
sample between a pair of filter sheets within 60 seconds
of lifting it, subjecting it to a pressure of 0.69 mN/m2
for 5 seconds and lightly wiping the water from the
sample, satisfies the following requirement (1):
(DCf-HCf) _ 10 (%) (1),
and in that the length LPD (mm) in the warp (or wale)
direction and the length LFD (mm) in the weft (or course)
direction for a sample of the dry woven or knitted fabric
prepared by taking a square sample with a 30 cm width in
the warp (or wale) direction and a 30 cm length in the
weft (or course) direction from the woven or knitted
fabric and allowing it to stand for 24 hours in an
environment at a temperature of 20 C, 65% RH, and the
length LPH (mm) in the warp (or wale) direction and the
length LFH (mm) in the weft (or course) direction for a
sample of the water wetted woven or knitted fabric
prepared by immersing the woven or knitted fabric sample
in water at a temperature of 20 C for 2 hours, lifting it
out from the water, sandwiching the sample between a pair
of filter sheets within 60 seconds of lifting it,
subjecting it to a pressure of 0.69 mN/m2 for 5 seconds
and lightly wiping the water from the sample, are used in
the following requirements (2) and (3);
RP(%) = ((LPH-LPD)/LPD) x 100 (2)
RF(%) = ( (LFH-LFD) /LFD) x 100, (3)
to calculate the change in dimensions RP (%) representing
the proportion of the difference between the length when
wet (LPH) and the length when dry (LPD) with respect to
the length when dry (LPD) for the warp (or wale)
direction of the woven or knitted fabric, and the change
in dimensions resizing factor RF (%) representing the
proportion of the difference between the length when wet
(LFH) and the length when dry (LFD) with respect to the
length when dry (LFD) for the weft (or course) direction
of the woven or knitted fabric, the average RA of which
satisfies the following requirement (4):
CA 02580530 2007-03-14
- 4 -
RA( o) (RP + RF) /2 5 5%, (4)
whereby the air space is reduced by wetting with water.
In the crimped filament-containing woven or knitted
fabric of the invention which has a decreased air space
upon wetting with water, preferably the crimped filaments
A are selected from among crimped conjugated fibers which
differ from one another in terms of water-absorbing and
self-extending properties, which are composed of a
polyester resin component and a polyamide resin component
bonded in a side-by-side fashion, and which have crimps
formed by expression of their latent crimping
performance.
Also, the polyester resin component in the crimped
filament-containing woven or knitted fabric of the
invention which has a decreased air space upon wetting
with water is preferably composed of a modified
polyethylene terephthalate resin comprising 5-
sodiumsulfoisophthalic acid copolymerized in an amount of
2.0 to 4.5 mole percent based on the acid component
content.
The crimped filaments A in the crimped filament-
containing woven or knitted fabric of the invention which
has a decreased air space upon wetting with water are
preferably used in yarn twisted at the number of twists
of 0 to 300 T/m.
The filaments B in the crimped filament-containing
woven or knitted fabric of the invention which has a
decreased air space upon wetting with water are
preferably formed of a polyester resin.
The woven or knitted fabric, of the crimped
filament-containing woven or knitted fabric of the
invention which has a decreased air space upon wetting
with water, preferably has a multilayer woven or knitted
structure with two or more layers, wherein at least one
layer of the multilayer woven or knitted structure
comprises the crimped filaments A at a content of 30 to
100 wt% of the total layer weight, and at least one other
CA 02580530 2007-03-14
- 5 -
layer comprises the filaments B at a content of 30 to 100
wt% of the total layer weight.
The woven or knitted fabric, of the crimped
filament-containing woven or knitted fabric of the
invention which has a decreased air space upon wetting
with water, may be a knitted fabric with a tubular
knitting structure, the composite loops of which tubular
knitting structure are formed from the crimped filaments
A and filaments B.
The woven or knitted fabric, of the crimped
filament-containing woven or knitted fabric of the
invention which has a decreased air space upon wetting
with water, may be a woven fabric with a weave structure,
wherein either or both the warp and weft yarns may be
composed of paralleled yarn comprising yarn made of the
crimped filaments A and yarn made of the filaments B.
In the woven or knitted fabric, of the crimped
filament-containing woven or knitted fabric of the
invention which has a decreased air space upon wetting
with water, the yarns made of the crimped filaments A and
the yarns made of the filaments B may be arranged
alternately with every one yarn being in either or both
the warp and weft directions or in either or both the
course and wale directions.
In the crimped filament-containing woven or knitted
fabric of the invention which has a decreased air space
upon wetting with water, preferably the yarns made of the
crimped filaments A and the yarns made of the filaments B
are combined with each other to form a core-in-sheath
type composite yarn, wherein the core of the composite
yarn is composed of the filament B yarns and the sheath
is composed of the crimped filament A yarns.
In the crimped filament-containing woven or knitted
fabric of the invention which has a decreased air space
upon wetting with water, preferably the filaments B are
selected from among elastic fibers with a breaking
elongation of 300% or greater.
CA 02580530 2007-03-14
_ ~ =
- 6 -
The woven or knitted fabric, of the crimped
filament-containing woven or knitted fabric of the
invention which has a decreased air space upon wetting
with water, preferably has an air permeability upon
wetting with water which is at least 20% lower than the
air permeability upon drying.
The crimped filament-containing woven or knitted
fabric of the invention which has a decreased air space
upon wetting with water is preferably a dyeing treatment
applied fabric.
The crimped filament-containing woven or knitted
fabric of the invention which has a decreased air space
upon wetting with water is also preferably a water
absorption treatment applied fabric.
The crimped filament-containing woven or knitted
fabric of the invention which has a decreased air space
upon wetting with water is also preferably a water
repellent treatment applied fabric.
The process for production of the crimped filament-
containing woven or knitted fabric of the invention is a
process for production of a crimped filament-containing
woven or knitted fabric which has a decreased air space
upon wetting with water, according to the present
invention, the process being characterized by comprising
a step of producing a precursor woven or knitted fabric
from uncrimped fibers for formation of crimped filaments
A which express crimping by heat treatment and wherein
the crimps have a property such that the percentage of
crimp decreases upon wetting with water, and fibers for
formation of filaments B comprising at least one type
selected from among fibers which do not express crimping
by the heat treatment, and fibers which express crimping
by the heat treatment but wherein the crimps have a
property such that the percentage of crimp substantially
does not decrease upon wetting with water, and a step
wherein the precursor woven or knitted fabric is
subjected to heat treatment to form a woven or knitted
CA 02580530 2007-03-14
= .y '
- 7 -
fabric containing the crimped filaments A and the
filaments B.
In the process for production of the crimped
filament-containing woven or knitted fabric of the
invention, preferably the fibers for formation of the
crimped filaments A are selected from among uncrimped
conjugated fibers made of a polyester resin component and
a polyamide resin component, which differ in their
moisture-absorbing and self-elongating properties and are
combined in a side-by-side structure.
In the process for production of the crimped
filament-containing woven or knitted fabric of the
invention, preferably the polyester resin component in
the uncrimped fibers includes a polyester resin with an
intrinsic viscosity of 0.30 to 0.43, and the polyamide
resin component includes a polyamide resin with an
intrinsic viscosity of 1.0 to 1.4.
In the process for production of the crimped
filament-containing woven or knitted fabric of the
invention, preferably the uncrimped fibers have, after
crimping treatment in boiling water,
(1) a dry percentage of crimp DC in the range of 1.5
to 13% after standing for 24 hours in an environment at a
temperature of 20 C, 65% RH,
(2) a wet percentage of crimp HC in the range of 0.5
to 7.0% immediately after immersion in water at a
temperature of 20 C for 2 hours, and
(3) a difference between the dry percentage of crimp
DC and wet percentage of crimp HC (DC-HC) of 0.5% or
greater.
A textile product of the invention includes a
crimped filament-containing woven or knitted fabric of
the invention which has a decreased air space upon
wetting with water.
The textile product of the invention is preferably
selected from among outer garments, sportswear and
underwear.
CA 02580530 2007-03-14
= n~ =
- 8 -
A woven or knitted fabric of the invention has an
air space which decreases by wetting with water and
increases by drying, and therefore the visibility is not
greater upon wetting, such as wetting caused by sweat,
and the waterproof property of the woven or knitted
fabric in rain, for example, is improved. A crimped
filament-containing woven or knitted fabric of the
invention is therefore useful for outer garments,
sportswear and inner clothing materials.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a cross-sectional view showing the
structure of an example of a crimped filament whose
percentage of crimp decreases upon wetting with water, in
a woven or knitted fabric of the invention.
Fig. 2 is a cross-sectional view showing the
structure of another example of a crimped filament whose
percentage of crimp decreases upon wetting with water, in
a woven or knitted fabric of the invention.
Fig. 3 is a cross-sectional view showing the
structure of still another example of a crimped filament
whose percentage of crimp decreases upon wetting with
water, in a woven or knitted fabric of the invention.
BEST MODE FOR CARRYING OUT THE INVENTION
A woven or knitted fabric of the invention comprises
crimped filaments A whose percentage of crimp decreases
upon wetting with water, and filaments B composed of at
least one type selected from among filaments with no
crimps and crimped filaments which undergo substantially
no change in percentage of crimp upon wetting with water.
When a woven or knitted fabric of the invention is wetted
by, for example, sweat or rain, the crimped filaments A
undergo a decrease in percentage of crimp and their
apparent lengths are extended. On the other hand, the
filaments B undergo essentially no change in percentage
of crimp due to wetting and therefore exhibit no change
1 / CA 02580530 2007-03-14
' A - 9 -
in apparent length, so that the woven or knitted fabric
dimensions are virtually unaltered. Consequently, the
air space of the woven or knitted fabric is reduced by
the crimped filaments A whose apparent lengths have been
increased. When the woven or knitted fabric is dried,
however, there is virtually no change in the crimping or
apparent lengths of the filaments B, while the crimped
filaments A increase their percentage of crimp and
exhibit a shortening of their apparent lengths, thereby
increasing the air space of the woven or knitted fabric.
In order for a woven or knitted fabric of the
invention to exhibit a decreased air space upon wetting
with water, it is essential that the percentage of crimp
DCf(%) of a sample of dry crimped filaments A prepared by
allowing a sample of the crimped filaments A taken from
the woven or knitted fabric to stand for 24 hours in an
environment at a temperature of 20 C, 65% RH, and the
percentage of crimp HCf(%) of a sample of the water wetted
crimped filaments A prepared by immersing a sample of the
crimped filaments A in water at a temperature of 20 C for
2 hours, lifting it out from the water, sandwiching the
sample between a pair of filter sheets within 60 seconds
of lifting it, subjecting it to a pressure of 0.69 mN/m2
for 5 seconds and lightly wiping the water from the
sample, satisfy the following requirement (1):
(DCf-HCf) _ 10 (%) (1),
and that when the length LPD (mm) in the warp (or wale)
direction and the length LFD (mm) in the weft (or course)
direction are measured for a sample of the dry woven or
knitted fabric prepared by taking a square sample with a
30 cm width in the warp (or wale) direction and a 30 cm
length in the weft (or course) direction from the woven
or knitted fabric and allowing the woven or knitted
fabric sample to stand for 24 hours in an environment at
a temperature of 20 C, 65% RH, and the length LPH (mm) in
the warp (or wale) direction and the length LFH (mm) in
CA 02580530 2007-03-14
~ .
- 10 -
the weft (or course) direction are measured for a sample
of the water wetted woven or knitted fabric prepared by
immersing the woven or knitted fabric sample in water at
a temperature of 20 C for 2 hours, lifting it out from the
water, sandwiching the sample between a pair of filter
sheets within 60 seconds of lifting it, subjecting it to
a pressure of 0.69 mN/m2 for 5 seconds and lightly wiping
the water from the sample, and the values for LPD, LFD,
LPH and LFH are used in the following requirements (2)
and (3):
RP ( o ) = ( (LPH-LPD) /LPD) x 100 (2)
RF ( o ) = ( (LFH-LFD) /LFD) x 100, ( 3 )
to calculate the change in dimensions RP (%) representing
the proportion of the difference between the length when
wet (LPH) and the length when dry (LPD) with respect to
the length when dry (LPD) for the warp (or wale)
direction of the woven or knitted fabric, and the change
in dimensions RF (%) representing the proportion of the
difference between the length when wet (LFH) and the
length when dry (LFD) with respect to the length when dry
(LFD) for the weft (or course) direction of the woven (or
knitted) fabric, the average RA thereof satisfies the
following requirement (4):
RA(%) = (RP + RF) /2 <_ 5%. (4)
The value of (DCf-HCf) is preferably 15 to 30%, and
the RA value is preferably 1 to 3%. If the (DCf-HCf)
value is less than 10% and/or the RA value is larger than
5%, elongation of the woven or knitted fabric as a whole
will absorb the extension in apparent lengths of the
crimped filaments A by the reduction in percentage of
crimp of the crimped filaments A when the woven or
knitted fabric is wetted with water, thus preventing
reduction in the air space of the woven or knitted
fabric.
The percentage of crimp of the crimped filaments A
in the woven or knitted fabric is measured by the
following method.
CA 02580530 2007-03-14
= .,r
- - 11 -
A test woven or knitted fabric is allowed to stand
for 24 hours in an atmosphere at a temperature of 20 C,
65% RH and then 30 cm x 30 cm strips are cut from the
woven or knitted fabric in the same direction as the
woven or knitted fabric (n=5). Crimped filaments A are
removed from each of the strips and subjected to a load
of 1.76 mN/dtex (200 mg/de) and the filament lengths LOf
are measured, and then after 1 minute of releasing the
load, a load of 0.0176 mN/dtex (2 mg/de) is applied and
the filament lengths Llf are measured. Also, the
filaments are immersed for 2 hours in water at a
temperature of 20 C and then removed and the water is
wiped off gently with filter paper, after which a load of
1.76 mN/dtex (200 mg/de) is applied, the filament lengths
LOf' are measured, and then after 1 minute of releasing
the load, a load of 0.0176 mN/dtex (2 mg/de) is applied
and the filament lengths L1f' are measured. The measured
values are used in the following formulas to calculate
the percentage of crimp when dry DCf(%), the percentage
of crimp when wet HCf(%) and the difference in
percentages of crimp when dry and when wet (DCf-HCf)(o).
The average of the number n (5) is calculated.
Dry percentage of crimp DCf(%) = ((LOf-Llf)/LOf) x
100
Wet percentage of crimp HCf(%) =((LOf'-Llf')/LOf')
x 100
It is essential for the crimped filaments A taken
from the woven or knitted fabric to be crimped filaments
wherein the difference between the dry percentage of
crimp DC(%) and wet percentage of crimp HC(%) (DC-HC) is
at least 10%.
Such crimped filaments A are preferably selected
from among crimped conjugated fibers which differ from
one another in terms of water-absorbing and self-
extending properties, are composed of a polyester resin
component and a polyamide resin component bonded in a
side-by-side fashion, and have crimps formed by
CA 02580530 2007-03-14
12 -
expression of their latent crimping performance.
As polyester resin components to be used for the
conjugated fibers there are preferred those having high
adhesion with the aforementioned polyamide resin
component, and for example, there are preferably used
modified polyesters such as polyethylene terephthalate,
polypropylene terephthalate or polybutylene terephthalate
which are copolymerized with compounds which have an
alkali or alkaline earth metal or phosphonium salt of
sulfonic acid, and which have one or more functional
groups with ester-forming capability. Particularly
preferred among these are modified polyethylene
terephthalate copolymerized with the aforementioned
compounds because of their general purpose utility and
low polymer cost. Examples of copolymerizing components
in this case include 5-sodiumsulfoisophthalic acid and
its ester derivatives, 5-phosphoniumisophthalic acid and
its ester derivatives, sodium p-hydroxybenzenesulfonate,
and the like. Preferred among these is 5-
sodiumsulfoisophthalic acid. The copolymerization
content is preferably in the range of 2.0 to 4.5 mole
percent with respect to the moles of the acid component
in the polyester resin. If the copolymerization content
is less than 2.0 mole percent, excellent crimping
performance is exhibited but peeling may occur at the
bonding interface between the polyamide resin component
and polyester resin component. Conversely, if the
copolymerization content is greater than 4.5 mole
percent, crystallization of the polyester resin component
will be inhibited during stretching heat treatment, thus
requiring a higher stretching heat treatment temperature
level than usual, and potentially leading to numerous
yarn breaks.
On the other hand, the polyamide resin component is
not particularly restricted so long as it has an amide
bond in the main chain, and as examples there may be
mentioned nylon-4, nylon-6, nylon-66, nylon-46 and nylon-
CA 02580530 2007-03-14
= - 13 -
12. Among these nylon-6 and nylon-66 are particularly
preferred from the viewpoint of general utility, polymer
cost and reeling stability.
The polyester resin component and polyamide resin
component may also contain publicly known additives such
as pigments, delustering agents, anti-fouling agents,
fluorescent brighteners, flame retardants, stabilizers,
antistatic agents, light fastness agents, ultraviolet
absorbers and the like.
There are no particular restrictions on the cross-
sectional profile of side-by-side conjugated fibers for
the crimped filaments A, and the bonding line between the
polyester resin component and the polyamide resin
component in the cross-sectional shape may be essentially
straight linear or a completely straight line. Examples
of cross-sectional shapes for the conjugated fibers are
shown in Figs. 1 to 3. In Fig. 1, the conjugated fiber 1
has a circular cross-sectional profile and is composed of
a polyester resin component 2 and polyamide resin
component 3 bonded together, with an essentially straight
linear bonding line. In Fig. 2, the conjugated fiber 1
has an oval cross-sectional profile and is composed of a
polyester resin component 2 and polyamide resin component
3 bonded together, with an essentially straight linear
bonding line. In Fig. 3, the conjugated fiber 1 has a
circular cross-sectional shape and is composed of a
polyester resin component 2 and polyamide resin component
3 bonded together, but the polyamide resin component 3
has a roughly circular cross-sectional profile and is
situated in the polyester resin component also having a
roughly circular cross-sectional profile, in a positional
relationship approximating an eccentric core-in-sheath
structure. However, a portion of the periphery of the
polyamide resin component 3 is exposed and forms a part
of the periphery of the conjugated fiber.
The cross-sectional profile of the conjugated fiber
may be, instead of circular or oval, polygonal such as
CA 02580530 2007-03-14
14 -
triangular or rectangular, or star-shaped or even hollow.
However, the cross-sectional profile of the conjugated
fiber is preferably circular in order to efficiently
decrease the percentage of crimp upon wetting with water.
The weight ratio of the two resin components in the
conjugated fibers for the crimped filaments A is not
particularly restricted, but the weight ratio of the
polyester resin component with respect to the polyamide
resin component is preferably in the range of 30:70 to
70:30 and more preferably 40:60 to 60:40.
There are no particular restrictions on the
individual filament thickness of the crimped filaments A
or on the number of individual filaments of the crimped
filaments A contained in the crimped filament yarn, but
the individual filament thickness is preferably 1 to 10
dtex and more preferably 2 to 5 dtex. The number of
individual filaments in the crimped filament A yarns is
preferably 10 to 200 and more preferably 20 to 100.
Uncrimped side-by-side conjugated fibers composed of
two different resin components as described above have a
latent crimping property, and therefore express crimps
when subjected to heat treatment such as, for example,
high-temperature dyeing treatment. In such crimped
conjugated fibers, preferably the polyamide resin
component is situated on the inner portions of the
crimps, while the polyester resin component is situated
on the outer portions of the crimps. When crimped
conjugated fibers having such a crimp structure are
wetted with water, the polyamide resin component situated
on the inner portions of the crimps are swelled by the
water and expand while the polyester resin component
situated on the outer portions of the crimps do not swell
with water and their lengths are unchanged, such that the
percentage of crimp of the conjugated fibers is reduced,
and the apparent lengths increase. On the other hand,
when the water-wetted crimped conjugated fibers are
dried, the polyamide resin component shrinks while the
CA 02580530 2007-03-14
. ,~ =
= - 15 -
polyester resin component undergoes no change in length,
such that the percentage of crimp of the conjugated
fibers increases and the apparent length of the crimped
conjugated fibers is shortened.
The crimped filaments A are preferably in untwisted
yarn or false twisted yarn with no more than 300 T/m
twists, in order to facilitate reduction in the
percentage of crimp and lengthening upon wetting with
water. Untwisted filaments are especially preferred.
With strong twisted yarn having strong twisting with
greater than 300 T/m, the crimping is sometimes reduced
upon wetting with water.
Also, yarn comprising the crimped filaments may be
subjected to, for example, interlacing air treatment
and/or false twisting treatment, and such treatment may
cause interlacing of the individual filaments in the yarn
at an interlacing number of about 20 to 60/m.
As long as the aforementioned conditions are
satisfied, there are no particular other restrictions on
the type of filaments B used in a woven or knitted fabric
of the invention, i.e. the filaments which are uncrimped
and undergo essentially no change in percentage of crimp
upon wetting with water. Here, the phrase "undergo
essentially no change in percentage of crimp upon wetting
with water" means that the dry percentage of crimp DC(%)
when the filaments are dried under the conditions
described above and the wet percentage of crimp HC(%)
when they are wetted with water under the conditions
described above (DC-HC) is less than 0.5(%).
The filaments B used for a woven or knitted fabric
of the invention include filaments suitable for clothing,
and may be polyesters such as polyethylene terephthalate,
polytrimethylene terephthalate and polybutylene
terephthalate, polyamides such as nylon-6 and nylon-66,
polyolefins such as polyethylene and polypropylene,
synthetic filaments formed from acrylic compounds, para-
or meta-aramids and their modified synthetic resins,
CA 02580530 2007-03-14
16 -
natural fibers, regenerated fibers, semi-synthetic
fibers, polyurethane-based elastic fibers and polyether
ester-based elastic fibers. Preferred among these are
polyethylene terephthalate, polypropylene terephthalate
and polybutylene terephthalate, as well as polyester
filaments composed of modified polyesters obtained by
copolymerization of these with copolymerizing components,
because of their high dimensional stability when wet and
their excellent compatibility with the crimped filaments
A (combined filament properties, mixed knitting or mixed
weaving properties and dyeing properties). There are
also no particular restrictions on the individual
filament thickness of the filaments B or on the number of
individual filaments (number of filaments) in yarn
comprising the filaments B, but for increased
hygroscopicity of the woven or knitted fabric and further
improved performance of air permeability when wet, the
individual filament thickness is preferably 0.1 to 5 dtex
(more preferably 0.5 to 2 dtex) and the number of
filaments per yarn is preferably in the range of 20 to
200 and more preferably 30 to 100. The yarn comprising
the filaments B can be subjected to interlacing air
treatment and/or ordinary false twisting treatment. Such
treatment may cause interlacing of the individual
filaments in the yarn at an interlacing number of about
20 to 60/m.
A woven or knitted fabric of the invention comprises
the aforementioned crimped filaments A whose percentage
of crimp decreases upon wetting with water, and filaments
B made of uncrimped filaments and/or filaments which
undergo essentially no change in percentage of crimp upon
wetting. Both may be used as separate yarns to form the
woven or knitted fabric, or they may form the woven or
knitted fabric as combined filament yarn such as air-
mixed yarn, double twisted yarn, combined false twisted
crimped yarn, paralleled yarn and the like.
There are no particular restrictions on the texture
CA 02580530 2007-03-14
17 -
or number of layers for production of a woven or knitted
fabric. For example, there may be suitably used a woven
texture such as a plane weave, twill weave or satin
weave, or a knitted texture such as a plain stitch,
smooth knit, circular rib knit, seed stitch, plating
stitch, Denbigh stitch, half knit or the like. However,
there is no limitation to these. The layer structure for
composing a woven or knitted fabric may be single-layer
or multilayer with two or more layers.
Modes of woven or knitted fabrics include:
(1) woven or knitted fabrics having a multilayer
woven or knitted structure of two or more layers wherein
at least one of the layers of the multilayer woven or
knitted structure comprises the crimped filaments A at a
content of 30 to 100 wt% of the total weight of the
layer, and at least one other layer comprises the
filaments B at a content of 30 to 100 wt% of the total
weight of the layer,
(2) knitted fabrics having a tubular knitting
structure, with the composite loops of the tubular
knitting structure formed from both the crimped filaments
A and filaments B,
(3) woven fabrics having a woven texture, wherein
either or both the warp and weft yarn is composed of
paralleled yarn comprising yarn made of the crimped
filaments A and yarn made of the filaments B.
(4) woven or knitted fabrics wherein the yarns made
of the crimped filaments A and the yarns made of the
filaments B are arranged alternately with every one yarn
being in either or both the warp and weft directions or
in either or both the course and wale directions.
(5) woven or knitted fabrics wherein the yarns.made
of the crimped filaments A and the yarns made of the
filaments B are combined together to form a core-in-
sheath type composite yarn, wherein the core of the
conjugated yarn is composed of the filament B yarns and
the sheath is composed of the crimped filament A yarns.
CA 02580530 2007-03-14
- - 18 -
In the composite yarn having a core-in-sheath
structure for mode (5) described above, it is important
for the length LA of the sheath yarn made of the crimped
filaments A and the length LB of the core yarn made of
the filaments B to satisfy the relational expression: LA
> LB. That is, if LA <_ LB, wetting of the obtained woven
or knitted fabric will cause a reduced percentage of
crimp for the crimped filaments A from which the sheath
is formed, and when the apparent length is increased the
filament B yarns from which the core is formed will also
be elongated due to stretching by the elongated crimped
filament A sheath yarn, eventually creating a change in
dimensions in the woven or knitted fabric as a whole;
thus, decrease in the percentage of crimp and increase in
the apparent length of the crimped filaments A will not
contribute to a reduced the air space of the woven or
knitted fabric as a whole. The aforementioned relational
expression LA > LB can be satisfied by (1) a method
wherein a high heat-shrinkage yarn with a boiling water
shrinkage of 20% or greater is used as the core filament
B yarns for production of composite yarn comprising the
crimped filament A yarns for the sheath and the high
heat-shrinkage filament B yarns for the core, a precursor
woven or knitted fabric is produced from this composite
yarn, and the precursor woven or knitted fabric is
subjected to heat shrinkage treatment for heat shrinkage
of the filament B yarns in order to achieve the
expression LA > LB, and (2) a method wherein elastic
filaments are used as the filament B yarns and these are
mixed or paralleled with the crimped filaments A with the
elastic filaments B in an elongated state to produce a
precursor core-in-sheath composite yarn, after which the
elongation is removed from the precursor composite yarn,
elastic shrinkage is produced in the elastic filaments B
to achieve the expression LA > LB, and a woven or knitted
fabric is produced from the core-in-sheath composite
yarn.
CA 02580530 2007-03-14
- 19 -
In a woven or knitted fabric of the invention, the
lengths LA and LB of the core yarn and sheath yarn in the
core-in-sheath composite yarn may be measured by the
following method.
A test woven or knitted fabric is allowed to stand
for 24 hours in an environment at a temperature of 20 C,
65% RH, a sample with a 30 cm length in the warp (or
wale) direction and a 30 cm width in the weft (or course)
direction is taken from the woven or knitted fabric, and
then a crimped filament A yarn and filament B yarn are
taken from core-in-sheath composite yarn oriented in the
same direction. The length LA of the crimped filament A
yarn is measured under a load of 1.76 mN/dtex, and the
length LB of the filament B yarn is measured under a load
of 1.76 mN/dtex if it is a non-elastic filament yarn with
a breaking elongation of up to 200%, or under a load of
0.0088 mN/dtex if it is an elastic filament yarn with a
high breaking elongation exceeding 20%.
The elastic filaments used as filaments B in a woven
or knitted fabric of the invention preferably have a
breaking elongation of 300% or greater.
The process for producing a woven or knitted fabric
of the invention comprises a step of producing a
precursor woven or knitted fabric from uncrimped fibers
for formation of crimped filaments A which express
crimping by heat treatment and wherein the crimps have a
property such that the percentage of crimp decreases upon
wetting with water, and fibers for formation of filaments
B comprising at least one type selected from among fibers
which do not express crimping by the heat treatment, and
fibers which express crimping by the heat treatment but
wherein the crimps have a property such that the
percentage of crimp substantially does not decrease upon
wetting with water, and a step wherein the precursor
woven or knitted fabric is subjected to heat treatment to
form a woven or knitted fabric containing the crimped
filaments A and the filaments B.
CA 02580530 2007-03-14
- 20 -
In the process of the invention, preferably the
fibers for formation of the crimped filaments A are
selected from among uncrimped conjugated fibers made of a
polyester resin component and a polyamide resin
component, which differ in their moisture-absorbing and
self-extending properties and are bonded in a side-by-
side fashion. Also, preferably the polyester resin
component of the uncrimped fibers includes a polyester
resin with an intrinsic viscosity of 0.30 to 0.43, and
the polyamide resin component includes a polyamide resin
with an intrinsic viscosity of 1.0 to 1.4. The intrinsic
viscosity of the polyester resin component of the
uncrimped fibers is more preferably 0.35 to 0.40 and the
intrinsic viscosity of the polyamide resin is more
preferably 1.2 to 1.4. The intrinsic viscosity of the
polyester resin is measured at a temperature of 35 C with
ortho-chlorophenol as the solvent, and the intrinsic
viscosity of the polyamide resin is measured at a
temperature of 30 C with m-cresol as the solvent.
In the aforementioned production process, an
intrinsic viscosity of the polyester resin component
higher than 0.43 yields a conjugated fiber with physical
properties similar to fiber composed of a polyester resin
component alone, and can prevent reduction in the air
space when the woven or knitted fabric is wetted with
water. Also, an intrinsic viscosity of the polyester
resin component of less than 0.30 excessively reduces the
viscosity of the molten polyester resin component during
the melt spinning step, resulting in insufficient fiber
formability, increased generation of fluff in the
obtained conjugated fibers, and inadequate quality and
production efficiency for the conjugated fibers.
The spinneret used to produce the side-by-side
conjugated filaments A may be one as shown in Fig. 1 of
Japanese Unexamined Patent Publication No. 2000-144518.
The extrusion openings for the high viscosity resin
component and the extrusion openings for the low
CA 02580530 2007-03-14
- 21 -
viscosity resin component in this spinneret are
separated, in a design wherein the cross-sectional area
of the extrusion openings for the high viscosity resin is
increased to lower the extrusion rate. This type of
spinneret is used for passage of the molten polyester
resin component through the high viscosity resin
extrusion openings and passage of the molten polyamide
resin component through the low viscosity resin extrusion
openings, joining the two types of melt flows in a side-
by-side fashion and cooling them to solidification. In
this melt spinning step, the weight ratio of the
polyester resin component with respect to the polyamide
resin component is preferably 30:70 to 70:30, and more
preferably 40:60 to 60:40.
For production of the aforementioned side-by-side
conjugated fibers, the unstretched fiber yarns (bundled)
produced in the melt spinning step may be first wound up
and then supplied to a stretching step (separate
stretching), or the melt spun unstretched filament yarns
(unbundled) may be supplied directly to a stretching heat
treatment step without winding up (direct stretching).
The stretching step may be carried out under ordinary
conditions. For example, in a direct stretching system,
the spinning step is carried out at a spinning speed of
1000 to 3500 m/m.in, and the obtained unstretched fiber
yarn is immediately stretched at a desired draw ratio at
a temperature of 100 to 150 C and wound up. The draw
ratio is appropriately set so that the finally obtained
conjugated fiber has a breaking elongation of preferably
10 to 60% and more preferably 20 to 45%, and a tensile
strength of preferably 3.0 to 4.7 cN/dtex and more
preferably 3.0 to 4.0 cN/dtex.
The uncrimped fibers of the conjugated fibers for
the crimped filament A obtained by the production process
of the invention preferably have, after crimping
treatment in boiling water,
(1) a dry percentage of crimp DC in the range of 1.5
CA 02580530 2007-03-14
= - 22 -
to 13% after standing for 24 hours in an environment at a
temperature of 20 C, 65% RH,
(2) a wet percentage of crimp HC in the range of 0.5
to 7.0% immediately after immersion in water at a
temperature of 20 C for 2 hours, and
(3) a difference between the dry percentage of crimp
DC and wet percentage of crimp HC (DC-HC) of 0.5% or
greater.
The dry percentage of crimp DC and wet percentage of
crimp HC are measured by the following methods.
A wind-up frame with a circumference of 1.125 m is
used for rewinding under a load of 49/50 mN x 9 x total
tex (0.1 gf x total denier) at a fixed speed for 10 winds
to produce a small skein, the small skein is twisted into
a double ring and placed in boiling water while subjected
to an initial load of 49/2500 mN x 20 x 9 x total tex (2
mg x 20 x total denier) for 30 minutes of treatment,
after which it is dried for 30 minutes with a drier at
100 C and then placed in dry heat at 160 C while subjected
to the initial load for 5 minutes of treatment. The
initial load is removed after the dry heat treatment, and
after standing for at least 24 hours in an environment at
a temperature of 20 C, 65% RH, the initial load and 98/50
mN x 20 x 9 x total tex (0.2 gf x 20 x total denier)
double load are applied, the skein length LO is measured,
the double load alone is immediately removed, and the
skein length L1 one minute after removing the load is
measured. The skein is then immersed for 2 hours in
water at a temperature of 20 C while under the initial
load, and after removal and lightly wiping off the water
with filter paper, it is subjected to the initial load
and the double load, the skein length LO' is measured,
the double load alone is immediately removed, and the
skein length L1' one minute after removing the load is
measured. These measured values are inserted into the
following formula to calculate the dry percentage of
CA 02580530 2007-03-14
- 23 -
crimp (DC), wet percentage of crimp (HC) and the
difference in dry and wet percentage of crimps (DC-HC).
Dry percentage of crimp DC(%) =((L0-L1)/L0) x 100
Wet percentage of crimp HC(%) =((L0'-L1')/LO') x
100
When the dry percentage of crimp of the conjugated
fiber is smaller than 1.5%, the change in percentage of
crimp when wet is reduced, and therefore the change in
air permeability of the woven or knitted fabric may be
smaller. Conversely, when the dry percentage of crimp of
the conjugated fiber is greater than 13%, crimping is
strong enough to inhibit change in crimping when wet, and
the change in air permeability of the woven or knitted
fabric may likewise be smaller. If the difference in
percentage of crimp of the conjugated fiber when dry and
when wet (DC-HC) is less than 0.5%, the change in air
permeability of the woven or knitted fabric may be
excessively small.
In the process for production of a woven or knitted
fabric of the invention, the aforementioned uncrimped
conjugated fibers, and the filaments B which are
uncrimped with a hot water shrinkage of 20% or greater or
crimped with a percentage of crimp which is essentially
unchanged upon wetting, are used to weave or knit a
precursor woven or knitted fabric, which is then
subjected to dyeing wherein the heat of dyeing produces
crimps in the conjugated fibers to produce a woven or
knitted fabric containing crimped filaments A. When a
core-in-sheath type composite yarn is obtained using the
crimped conjugated filament A yarn and the filament B
yarn, it is important for the length LA of the crimped
filament A yarn to be larger than the length LB of the
filament B yarn in the composite yarn.
There are no special restrictions on the woven or
knitted texture of a woven or knitted fabric according to
the invention.
In the production process of the invention, the
CA 02580530 2007-03-14
- 24 -
temperature for the dyeing treatment is preferably 100 to
140 C and more preferably 110 to 135 C, and the dyeing
time is preferably in the range of from 5 to 40 minutes
as the keep time at the top temperature. Dyeing of the
woven or knitted fabric under these conditions will allow
the uncrimped conjugated fibers to express crimping by
the heat shrinkage difference between the polyester resin
component and the polyamide resin component. The
polyester resin component and polyamide resin component
may be selected from among the aforementioned polymers to
yield a crimped structure with the polyamide component
situated on the inner sides of the crimps.
The woven or knitted fabric which has been dyed is
usually subjected to final dry heat setting. The
temperature of the final dry heat setting is preferably
120 to 200 C and more preferably 140 to 180 C, and the
time is preferably in the range of 1 to 3 minutes. If
the temperature for the final dry heat setting is below
120 C, wrinkles created during the dyeing will tend to
remain, and the dimensional stability of the finished
product may be impaired. Conversely, if the temperature
for the final dry heat setting is higher than 200 C,
crimping of the conjugated fibers during dyeing will be
reduced and the fibers may harden and produce a hard feel
to the cloth.
In the woven or knitted fabric obtained in this
manner, the air permeability upon wetting is preferably
at least 20% lower than when dry, and more preferably 30
to 100%. The air permeability is a property
representative of the air space of the woven or knitted
fabric, and a lower air permeability of the woven or
knitted fabric means a smaller air space. The air
permeability is the value (ml/cm2/s) measured according to
JIS L 1096 1998, 6.27.1, A (Fragile-Type Air Permeability
Tester Method).
"Dry" in this case is the state of the sample after
CA 02580530 2007-03-14
25 -
standing for 24 hours in an environment at 20 C, 65% RH,
while "wet" is the state of the sample after immersion
for 2 hours in water at 20 C, sandwiching it between a
pair of filter sheets, subjecting it to a pressure of 490
N/m2 for one minute and lightly wiping the water off; the
air permeability is measured for each (n=5) and the
average is calculated.
The woven or knitted fabric of the invention is
preferably subjected to hygroscopic treatment and/or
water repellent treatment, depending on the purpose and
intended use. For example, it is preferably subjected to
hygroscopic treatment when the purpose is improving the
anti-visibility property of sportswear and underwear
caused by sweat. Hygroscopic treatment of the woven or
knitted fabric is preferred because it increases the
diffusion rate of sweat and prevents a sticky feel, while
also increasing the rate of change in crimping of the
crimped filaments A whose percentage of crimp decreases
upon wetting, and increasing the response speed for
improved anti-visibility. Also, water repellent
treatment is preferred when the purpose is improving the
waterproof properties of windbreakers or ski and
snowboard wear in rain. Water repellent treatment is
preferred because it increases the initial waterproofness
while lowering the air space of the woven or knitted
fabric by absorption of moisture and water by the crimped
filaments A whose percentage of crimp decreases upon
wetting, during periods when the water repellent coating
of the woven or knitted fabric surface repels rain,
thereby improving the waterproof properties.
The agent used for the hygroscopic treatment is
preferably polyethylene glycol or a derivative thereof,
or polyethylene terephthalate-polyethylene glycol
copolymer, adhered at 0.25 to 0.50 wt% with respect to
the weight of the woven or knitted fabric. The method
for hygroscopic treatment may be, for example, a bath
treatment method in which the hygroscopic agent is mixed
CA 02580530 2007-03-14
- 26 -
with the dyeing solution during dyeing, or a coating
method such as a method of dipping the woven or knitted
fabric in a hygroscopic treatment solution before the
final dry heat setting and squeezing it with a mangle, a
gravure coating method or a screen printing method.
On the other hand, the water repellent treatment is
preferably carried out until the water repellency of the
woven or knitted fabric after water repellent treatment
is at least level 4 according to JIS L 1092 6.2 (Spray
Test). An example is a method wherein a commercially
available fluorine-based water repellent (for example,
Asahi Guard LS-317 by Asahi Glass Co., Ltd.) is used as
the water repellent, if necessary with mixture of a
melamine resin and a catalyst, to prepare a treatment
agent with a water repellent agent content of about 3 to
15 wt%, and this treatment agent is used for treatment of
the surface of the fabric at a pickup rate of about 50 to
90%. The method for treatment of the surface of the
fabric with the water repellent agent may be a pad
method, spray method or the like, but a pad method is
most preferred from the standpoint of penetration of the
treatment agent to the interior of the fabric. The
pickup rate is the weight ratio (%) of the treatment
agent with respect to the weight of the fabric (before
applying the treatment agent).
When a woven or knitted fabric of the invention is
wetted by sweat or rain, the crimped filaments A extend
due to reduction in the amount of their own crimps.
Meanwhile, the filaments B do not extend even when wetted
and therefore maintain a fixed dimension of the woven or
knitted fabric, resulting in a lower air space of the
woven or knitted fabric and improved anti-visibility and
waterproof properties of the woven or knitted fabric.
In addition to the treatments described above,
ordinary methods may be employed to subject the woven or
knitted fabric of the invention to piling treatment,
ultraviolet blocking, or various treatments which confer
CA 02580530 2007-03-14
27 -
the functions of antibacterial agents, deodorants,
insecticides, luminous agents, retroreflective agents,
minus ion-generating agents and the like.
A crimped filament-containing woven or knitted
fabric with a reduced air space upon wetting with water
according to the invention may be used for production of
various types of textile products. Such textile products
include outer garments, sportswear, and underwear.
EXAMPLES
The present invention will now be explained in
greater detail through the following examples, with the
understanding that the invention is not limited in any
way to the examples. The following measurements were
conducted for the examples and comparative examples.
(1) Intrinsic viscosity of polyester
This was measured at 35 C using ortho-chlorophenol as
the solvent.
(2) Intrinsic viscosity of polyamide
This was measured at 30 C using m-cresol as the
solvent.
(3) Tensile strength and breaking elongation
A fiber sample was allowed to stand a day and a
night in a steady temperature and humidity chamber kept
in an atmosphere at 25 C, 60% RH, and then a sample length
of 100 mm was set in a Tensilon tester by Shimadzu
Laboratories Co., Ltd. and pulled at a rate of 200
mm/min, upon which the tensile strength at breakage
(cN/dtex) and the elongation (%) were measured. The
average value of n=5 was calculated.
(4) Boiling water shrinkage
The boiling water shrinkage (hot water shrinkage)
(%) was measured by the method specified according to JIS
L 1013 1998, 7.15. The average value of n=3 was
calculated.
(5) Percentage of crimp of conjugated fiber
CA 02580530 2007-03-14
- 28 -
A wind-up frame with a circumference of 1.125 m was
used for rewinding under a load of 49/50 mN x 9 x total
tex (0.1 gf x total denier) at a fixed speed for 10 winds
to produce a small skein, the small skein was twisted
into a double ring and placed in boiling water while
subjected to an initial load of 49/2500 mN x 20 x 9 x
total tex (2 mg x 20 x total denier) for 30 minutes of
treatment, after which it was dried for 30 minutes with a
drier at 100 C and then placed in dry heat at 160 C while
subjected to the initial load for 5 minutes of treatment.
The initial load was removed after the dry heat
treatment, and after standing for at least 24 hours in an
environment at a temperature of 20 C, 65% RH, the initial
load and the 98/50 mN x 20 x 9 x total tex (0.2 gf x 20 x
total denier) double load were applied, the skein length
LO was measured, the double load alone was immediately
removed, and the skein length Ll one minute after
removing the load was measured. The skein was then
immersed for 2 hours in water at a temperature of 20 C
while under the initial load, and after removal and
lightly wiping off the water with filter paper, it was
subjected to the initial load and the double load, the
skein length LO' was measured, the double load alone was
immediately removed, and the skein length L1' one minute
after removing the load was measured. These measured
values were inserted into the following formula to
calculate the dry percentage of crimp (DC), wet
percentage of crimp (HC) and the difference in dry and
wet percentages of crimp (DC-HC). The average value of
n=5 was calculated.
Dry percentage of crimp DC(%) =((L0-L1)/L0) x 100
Wet percentage of crimp HC(%) =((L0'-L1')/L0') x
100
(6) Percentage of crimp of crimped conjugated fibers
in woven or knitted fabric
The woven or knitted fabric was allowed to stand for
CA 02580530 2007-03-14
29 -
24 hours in an atmosphere at a temperature of 20 C, 65% RH
and then test strips with a length of 30 cm in the warp
(or wale) direction and a width of 30 cm in the weft (or
course) direction were taken from the woven or knitted
fabric (n=5). Crimped filaments A were removed from each
of the test strips and subjected to a load of 1.76
mN/dtex (200 mg/de) and the filament lengths LOf were
measured, and then after 1 minute of releasing the load,
a load of 0.0176 mN/dtex (2 mg/de) was applied and the
filament lengths Llf were measured. Also, the filaments
were immersed for 2 hours in water at a temperature of
C, removed and then placed between a pair of filter
sheets at a pressure of 0.69 mN/m2 for 5 seconds and the
water was wiped off gently, after which a load of 1.76
15 mN/dtex (200 mg/de) was applied, the filament lengths
LOf' were measured, and then after 1 minute of releasing
the load, a load of 0.0176 mN/dtex (2 mg/de) was applied
and the filament lengths Lif' were measured. The
measured values were used in the following formulas to
20 calculate the percentage of crimp when dry DCf(%), the
percentage of crimp when wet HCf(%) and the difference in
percentages of crimp when dry and when wet (DCf-HCf)(o).
The average of n=5 was calculated.
Dry percentage of crimp DCf ( o) = ((LOf-Llf)/LOf ) x
100
Wet percentage of crimp HCf(%) =((L0f'-Llf')/LOf')
x 100
(7) Air permeability
The air permeability was measured by the following
method as a property representing the air space of the
woven or knitted fabric. The air permeability when dry
(cc/cm2/s) and the air permeability when wet (cc/cm2/s)
were measured for a woven or knitted fabric sample
according to JIS L 1096 1998, 6.27.1, A (Fragile-Type Air
Permeability Tester Method), "Dry" was the state of the
sample after standing for 24 hours in an environment at
CA 02580530 2007-03-14
- 30 -
20 C, 65% RH, while "wet" was the state of the sample
after immersion for 2 hours in water at 20 C, sandwiching
it between a pair of filter sheets, subjecting it to a
pressure of 490 N/m2 for one minute and lightly wiping the
water off; the air permeability was measured for each
(n=5) and the average was calculated. The change in air
permeability was calculated by the following equation.
Change in air permeability (%) = ((air permeability
when dry) - (air permeability when wet))/(air
permeability when dry) x 100
(8) Change in dimensions RA of sample
The change in dimensions RA of a sample of the woven
or knitted fabric was calculated in accordance with the
following equations. The average was calculated for n=5.
RA(%) = (RP + RF) /2
RP(%) = ((LPH-LPD)/LPD) x 100
RF(%) = ( (LFH-LFD) /LFD) x 100
Here, LPH, LPD, LFH and LFD respectively represent
the lengths upon wetting with water and the lengths upon
drying in the warp (or wale) direction and the weft (or
course) directions of the sample, where the sample was in
a square form with a 30 cm length in the warp (or wale)
direction and a 30 cm width in the weft (or course)
direction from the woven or knitted fabric. LPH: a wet
length of the sample in the warp (or wale) direction
(mm), LPD: a dry length of the sample in the warp (or
wale) direction (mm), LFH: a wet length of the sample in
the weft (or course) direction (mm), LFD: a dry length of
the sample in the weft (or course) direction, "wet": a
state of the sample after immersion in water at 20 C for 2
hours, immediately sandwiching it between a pair of
filter sheets, subjecting it to a pressure of 0.69 mN/m2
for 5 seconds and lightly wiping the water off, "dry": a
state of the sample after standing for 24 hours in an
environment at 20 C, at 65% RH.
(9) Measurement of yarn length
CA 02580530 2007-03-14
= -
31 -
The woven or knitted fabric was allowed to stand for
24 hours in an environment at a temperature of 20 C, 65%
RH, and then a strip of 30 cm (in the warp (or wale)
direction) x 30 cm (in the weft (or course) direction)
was cut out (n=5). Next, a conjugated filament (A) yarn
and filament (B) yarn were taken from each strip, a load
of 0.0088 mN/dtex was applied in the case of an elastic
filament or a load of 1.76 mN/dtex in the case of a non-
elastic filament, and the length LA of the conjugated
filament A yarn and the length LB of the other filament B
yarn were measured. The average of n=5 was calculated.
Example 1
Nylon-6 with an intrinsic viscosity [il] of 1.3 and
modified polyethylene terephthalate copolymerized with
2.6 mole percent 5-sodiumsulfoisophthalic acid, having an
intrinsic viscosity [il] of 0.39, were melted at 270 C and
290 C, respectively, and the conjugated fiber spinneret
shown in Fig. 1 of Japanese Unexamined Patent Publication
No. 2000-144518 (wherein the spinning hole is a spinning
nozzle hole composed of two arc-shaped slits A and B
situated essentially on the same circumference at a
spacing (d), and where the area SA of the arc-shaped slit
A, the slit width A1, the area SB of the arc-shaped slit
B, the slit width B1 and the area SC defined by the inner
perimeters of the arc-shaped slits A and B simultaneously
satisfy the following inequalities [1] to [4]:
[1] B1 < A1
[2] 1.1 SA/SB <_ 1.8
[3] 0.4 (SA+SB)/SC <_ 10.0
[4] d/A1 3.0)
was used for extrusion of the polyethylene terephthalate
from slit A and the nylon-6 from slit B, at an extrusion
rate of 12.7 g/min each, followed by cooling to
solidification and lubricant application to form a side-
by-side undrawn conjugated fiber having the cross-
CA 02580530 2007-03-14
= - 32 -
sectional profile shown in Fig. 1. The filament was
preheated with a preheating roller at a speed of 1000
m/min and a temperature of 60 C, and then subjected to
drawing heat treatment between the preheating roller and
a heating roller heated to a temperature of 150 C at a
speed of 3050 m/min (drawing factor: 3.05), and wound up
to obtain an 86 dtex/24 fil uncrimped conjugated fiber.
The breaking tensile strength of the obtained drawn
conjugated fiber was 3.4 cN/dtex, and the breaking
elongation was 40%. When the percentage of crimp was
measured after boiling water treatment of the conjugated
fiber, the dry percentage of crimp DC was 3.3%, the wet
percentage of crimp HC was 1.6% and the difference
between the dry percentage of crimp DC and wet percentage
of crimp HC (DC-HC) was 1.7%.
The conjugated fiber yarns (without boiling water
treatment and without crimping or twisting) were arranged
in full set on the front reed of a 36 gauge tricot
knitting machine, while uncrimped polyethylene
terephthalate multifilament yarns (33 dtex/12 fil) with a
boiling water shrinkage of 20% were arranged in full set
on the back reed of the tricot knitting machine, for
knitting a tricot stitched fabric in a knitting structure
front 10-23, and back 12-10, with a 110/2.54 cm machine
course.
The tricot stitched fabric was dyed under conditions
with a maximum temperature of 130 C and a maximum
temperature keep time of 15 minutes, for manifestation of
the latent crimping property of the conjugated fibers,
thereby producing a crimped conjugated fiber yarn-
containing tricot knitted fabric; this was then subjected
to padding treatment using a treatment solution
containing 8 wt% of a fluorine resin-based water
repellent (ASAHIGUARDTM AG710, product of Asahi Glass Co.,
Ltd.), and then dried at a temperature of 100 C and
subjected to final dry setting at 160 C for 1 minute.
CA 02580530 2007-03-14
= -
33 -
The performance of the obtained tricot stitched
fabric was as follows.
LPH: 305 mm
LPD: 300 mm
LFH: 311 mm
RP : 1.7%
RF : 3.7%
RA : 2.7%
Dry air permeability: 14 ml/cm2/s
Wet air permeability: 10 ml/cmZ/s
Variation in air permeability: 40%
The knitted fabric had a reduced air space upon water
wetting and therefore a lower air permeability, and was
therefore satisfactory.
The yarn length (LA) of a conjugated fiber yarn
(crimped filament A yarn) taken from the knitted fabric
was 2700 mm, and the yarn length (LB) of a filament B was
1890 mm, and therefore LA was longer than LB. Also, the
dry percentage of crimp DCf of the crimped conjugated
filament A taken from the knitted fabric was 7%, the wet
percentage of crimp HCf was 52%, and the dry-wet
percentage of crimp difference (DCf-HCf) was 18%.
Comparative Example 1
The uncrimped conjugated fibers used in Example 1
were arranged in full set on the front reed and back reed
of a 28 gauge tricot knitting machine, for knitting a
tricot stitched fabric in a knitting structure of front
10-23 and back 12-10, with a 60/2.54 cm of courses on
machine. Dyeing and final dry heat setting were also
carried out on the resultant fabric in the same manner as
Example 1.
The obtained knitted fabric was unsatisfactory, with
LPH: 315 mm, LPD: 300 mm, LFH: 330 mm, LFD: 300 mm, RP:
5.0%, RF: 10.0%, RA: 7.5%, dry air permeability: 140
cc/cm2/s, wet air permeability: 250 cc/cm2/s and air
permeability variation: -79%, i.e. a large increase in
air permeability when wet. Also, for a conjugated fiber
CA 02580530 2007-03-14
34 -
taken from the fabric, the dry percentage of crimp DCf was
62%, the wet percentage of crimp HCf was 38% and the
difference in the dry and wet percentages of crimp (DCf-
HCf) was 22 0 .
INDUSTRIAL APPLICABILITY
According to the present invention, it is possible
to obtain woven and knitted fabrics with improved anti-
visibility and waterproof properties by efficient
reduction in the air space in a wet state as compared to
a dry state. The woven and knitted fabrics may be used
for outer garments, sportswear and underwear provide
effects of inhibited visibility by sweat and improved
waterproofness in rain, and therefore their industrial
value is very high.
