Note: Descriptions are shown in the official language in which they were submitted.
11~197
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a process for the
preparation of a suede~ e raised woven or knitted fabric.
More particularly, the present invention is ooncerned
with a process for producing a suede-like raised woven or
knitted fabric having an excellent writing effect (finger-
mark property), repulsive elasticity, wrin~le recovery
and feel.
~escription of the Prior Art
Heretofore, it has been known to produce a suede-
like fabric by applying an elastic polymerg especially a
polyurethane polymer to a raised fabric comprising extra
fine fibers.
For example, U.S. Patent No. 3,865,678, issued on
February 11~ 1975 to Okamoto et al, discloses a process
for the preparation of a suede-like raised woven fabric
which comprises: preparing a woven fabric whose weft is a
yarn consisting of a bundle of extra fine fibers produced
from an islands-in-sea type composite fiber, the mono-
filament denier of the extra fine fiber being 0.0001 to
0.4 denier, and whose warp is a false twisted textured
yarn or a potentially crimped composite yarn; raising the
surface of a woven fabric; impregnatin~ thus raised woven
fabric with an emulsion or organic solvent solution of
polyurethane polymer. U.S. Patent No. 4,051,287, issued on
September 27, 1977 to Hayashi et al and U.S. Patent t
Lf ~ 109 t~3~ ISs~ o~ 5t:)~, 1~ S?
Application Serial No. 79 ~ 18~ fik4~ o~ tia~~23~ lg77
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11~1197
Ozaki et al disclose a suede-like woven or knitted fabric
which was produced by applying a polyurethane polymer
solution to a raised woven or knitted fabric comprising
extra fine fibers obtained from hollow composite fibers 9
the hollow composite fiber being composed of at least
four alternately arranged segments of fiber-forming
polyester and fiber~forming polyamide which are mutually
adhered side~by-side and encompass a center hollow cavity
and which extend along the longitudinal axis of the
1~ fiber to form a tubular body.
An organic solvent solution or aqueous emulsion of
polyurethane polymer has been used in these prior arts.
The use of the organic solvent solution of polyurethane
polymer results in difficulty in the manufacturing
environmental control and treatment of the solvent waste.
The use of the aqueous emulsion of polyurethane polymer
has a disadvantage that the polyurethane polymer tends to
form coagulated particles, or gumming 9 on the rolls of a
mangle or the fabric in the impregnating process of the
fabric because of the poor emulsion stability of the
aqueous emulsion.
Furthera the process for the preparation of a
suede-like raised fabric which comprises applying a
polyurethane polymer to a raised fabric has the following :
disadvantage~ in view of the physical properties of the
obtained fabric. It is difficult to fully improve the
repulsive elasticity and wrinkle resistance of the raised
woven or knitted fabricg because it is difficult to
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11C~1~97
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effect uniform and thorough impregnation of the polyure-
thane polymer having high molecular- weight through the
fabric: When a polyurethane polymer is used in a highly
concentrated solution or emulsion, for exampleg an emul-
sion having more than about 5 ~ by weight of the poly-
urethane polymer, the raised surface of the fabric becomes
paper~like, and accordingly becomes greatly poor in
writing effect which is a marked characteristic of suede-
like raised woven or knitted fabrics.
Japanese Patent Application Laid-Open Nos. 155794J75
and 108395~75 disclose an urethane pre-polymer having an
isocyanate group blocked by bisulfites.
It is described in these prior arts that this urethane
pre polymer is good in aqueous li~uid stability, and
accordingly is free from gumming in the impregnating
process of a fabric, and the conventional woven or knitted
fabric treated with this pre-polymer has improved repul-
sive elasticity, wrinkle and shrinkage resistances. How-
ever, these prior arts neither disclose nor suggest an
application of this urethane pre-polymer to a raised
woven or knitted fabric comprising extra fine fibers.
SUMM~RY OF THE INVENTION
It has now been found by the present inventors that
if an aqueous liquid of urethane pre-polymer disclosed in
Japanese Patent Application Laid-Open Nos. 155794/75 and
108395/75, in the place of a conventional polyurethane
polymer, is applied to a raised woven or knitted fabric
comprising extra fine fibers in a specific amount and under
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197
a specific condition, the troubles, such as gumming, do
not occur in the pre-polymer applying process of the
fabric~ and further the fabric treated with the pre-
polymer has excellent properties ~hich cannot be expected
from the use of conventi.onal polyurethane polymer.
The present invention relates to a process for the
preparation of a suede-like raised woven or knitted fabric
which comprises the steps of: (1) preparing a raised
woven or knitted fabric comprising extra fine fibers, the'
monofilament denier of the extra fine fiber being in a
range of 0.0001 to 0.8; (2) applying to the fabric an
aqueous liquid of hydroscopic and heat-active urethane
pre-polymer having an isocyanate group blocked by bisulfites,
in a dry amount of 1 to 20 % by weight of the urethane
pre-polymer based on the weight of the fabric~ (3) heat-
treating the applied fabric at a tempera*ure of 100 to
180C to form a polyurethane polymer in the fabric; and
thereafter (4) buffing at least one surface of the result-
ant fabric.
BRIEF DESCRIPTION OF THE DR~WINGS:
- Figure 1 is a ,schematic cross-sectional view of a
hollow composite fi~er used in the present invention.
Figure 2 is a schematic cross-sectional view of an
islands-in-sea type composite f ber used in *he present
inventionO
Figure ~ is an explanatory view showing the method
of measuring bending stiffness and resilience, Figures 3a and
3b diagrammatically shcwing a test apparatus and Figure 3c is a graph of
repulsive force against distance waved in a sample te~t,
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11C~1~97
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~ESCRIPTION OF THE PREFERRED EMBODIMENTS
Any known extra fine fibers can be used in the
present invention. As for the known extra fine fibers,
there can be exemplified as follows:
S (1) Extra fine fibers obtained by dividing a hollow
composite fiber into each segment~ the hollow composite
fiber being composed of at least four alternately arranged
segments of fiber-forming polyester and fiber-forming
polyamide which are mutually adhered side-by-side encompass-
ing a center hollow cavity and which extend along thelongitudinal axis of the fiber to form a tubular body,
which are disclosed in U.S. Patent No. 4,051g287 and
~,loq,o 3~
. ~ U.S. Patent Ap~licati~n Se~ial No-. ~99,610.
(2) Extra fine fibers obtained by removing a matrix
polymer with a solvent ~hereof from a composite fiber
containing microfibers, the composite fiber being produced
by blending at lleast two incompatible fiber-forming
polymers, extruding the resultant mixture in the fiber
form and drawing the undrawn fiber, which are disclosed in
U.S. Patent No. 3,382,305, issued on May 7, 1968 to Breen.
(3) Extra fine fibers obtained by removing at least one
polymer with a solvent thereof from a mix-spun fiber, the
mix-spun fiber being produced by a wet, dry or melt spinning
of a mixture of two or more high molecular weight materials,
which are disclosed in U.S. Patent No. 3,424,604, issued on
January 28, 1969 to Fukushima et al.
~4) Extra fine fibers obtained by removing a sea
component from a highly oriented islands-in-sea type
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97
composite fiber, the islands-in sea type composite fiber
being produced by spinning simultaneously at least two
different polymers together9 which are disclosed in U.S.
Patent No. 39562,3749 issued on February 99 1971 to
Okamoto et al.
(S) Extra fine fibers obtained from a composite fiber,
the composite fiber being composed of a first polymer and
a second polymerg wherein the polymer components being
adhered each other along at 1east one longitudinally
extending contacting surface forming at least one sharp-
edge configuration, and the polymer components heing
readily separable by mechanical action or removing one
component to form filaments having a sharp-edge configura-
tion, which are disclosed in U.S. Patent No. 3~117,362,
issued on January 14, 1964 to Breen.
(6) Extra fine fibers obta-ned in accordance with the
~uper-drawing method which is disclosed in U.S. Patent
No. 2,578,899, issued on December 18, 1951 to Pace, or
another known high-speed spinning method.
As for the polymers used for the preparation of
extra fine fibers, there are preferably exemplified
polyesters, such as polyethylene terephthalate, and
polyamides, such as nylon 6 and nylon 66.
The monofilamen' denier of the extra fine fiber is
in the range of 0.0001 to 008, preferably 0.0001 to 0.5
and more preferably 0.01 to 0.5. When the denier is less
than 0.00019 surface abrasion and pilling resistance of
the raised woven or knitted fabric are not good. On the
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11~1197
other hand 3 when the denier is more than 0.8 9 feel or
touch of the raised woven or knitted fabric tends to be
rou~h and a suede-like touch is har~ly obtained.
The extra fine fibers as described in the preceding
(6) can be used for the preparation of a woven or knitted
fabric after making a bundle of the extra fine fibers 3
namely a multifilament yarn or a spun yarn consisting of
extra fine fibers. In the cases of extra fine fibers as
described in the aforesaid (1) to (5), the extra fine
fibers are preferably formed by dividing each composite
fiber as described in Sl) to (5) or by removing at least
one component of the composite fiber after a multifilament
yarn or a spun yarn is prepared from the composite fibers
or further a woven or knitted fabric is prepared from the
ob*ained yarns.
In the cases of extra fine fibers as described in
(2) to (5) wherein the extra fine fi~ers are formed by
removing at least one component of the composite fiber
with a solvent thereof, it is also possible to form the
extra fine fibers by removing at least one component of
the composite fiber with a solvent thereof after the
process of applying an urethane pre-polymer to the fabric
and the process of forming a polymethane polymer in the
fabric as described below.
In the present invention~ the multifilament yarn
means~ for example~ a single twist filament yarn, a twin
filament yarn, a triple filamen~ yarn, a "Taslan" textured
yarn (a trademark of Du Pont~ or a textured yarn having
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97
g
crimps obtained by a method such as false-twisting, stuffer
crimping 9 edge crimping and air jet-crimping.
A woven fabric employed in the present invention
is prepared using the multifilament yarn or spun yarn
c~nsisting of the extra fine fibers as a warp and/or weft
of the woven fabric.
In particular~ a satin fabric is preferably used
in the present invention, which is composed of a multi-
filament yarn or a spun yarn consisting of the extra fine
fibers of total denier ranging from 50 to 500 as the weft,
and a multifilament yarn, a mixed multifilament yarn9 a
spun yarn or a mixed spun yarn consisting of the conven-
tional fibers (whose monofilament denier is more than
about 1) of total denier rangin~ from 50 to 300 as the
warp. When it is desired to raise two surfaces (a surface
and back surface) of the fabric, a double faced woven
fabri.c having a satin structure in both surfaces is
preferably used. Among the satin fabrics~ 3-ply satin and
4-ply satin fabrics are particularly preferable. In
particularg a textured yarn having crimps which consists of
polyestersg such as polyethylene terephthalate or polyamides,
such as nylon 6 and nylon 66 is preferably used as a warp
yarn.
~ knitted fabric employed in the present invention
is prepared using the multifilament yarn or spun yarn
consisting of the extra fine fibers. When a warp knitted
fabric is employed, it is preferable that the front yarns
thereof are formed with a multifilament yarn or a spun
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yarn consisting of the extra fine fibers and the back yarns
t~nereof are formed with a multifilament yarng a mixed
multifilament yarn, * spun yarn or a mixed spun yarn
having the conventional denier. When a circular knitted
fabric is employed, it is preferable that both the front
and back portions or only the front portion thereof are
formed with a multifilament yarn or a spun yarn consisting
of the extra fine fibers.
A raised woven or knitted fabric used in the
present invention can be prepared by raising one or both
surfaces of the obtained woven or knitted fabric with a
conventional raising machine, such as emery raising
machine, teazel raising machine, wire raising machineg or
a roller sander maehine with sand paper or sand cloth.
In the case of extra fine fibers as described in
the aforesaid (1) or (5), the composite fiber contained in
the woven or knitted fabric is substantially divided into
each segment by the raising operation to form the extra
fine fibers. In the cases of extra fine fibers as described
in the aforesaid (2) to (5)~ the extra fine fibers are
fo~med by removing at least one polymer constituting the
composite fiber with a solvent thereof before or after the
raising operation of the wcven or knitted fabric. This
removing operation may be conducted after the process of
applying an urethane pre-polymer to the raised fabric and
the process of forming a polyurethane polymer in the
raised fabric, and before the process of buffing the
raised fabric as described below.
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1~1197
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Usually, the raised woven or knitted fabric is
dyed or printed using any conventional method after the
raising operation. If desired or necessary, shearing and/or
brushing operations may be applied to the dyed or printed
fabric. After drying, the dyed or printed fabric is
rinished by applying an urethane pre-polymer of the present
invention. If desired, the raised woven or knitted fabrie
may be dyed or printed after the process of applying the
urethane pre-polymer.
An urethane pre-polymer employed in the present
inven,ion is a hydroscopic and heat-active urethane pre-
polymer having one or more isocyanate groups blocked by
bisulfites. In particular a the urethane pre-polymer
having an oxyethylene group of 10 to 40 % by weight in the
molecule is preferable because the pre-polymer is easily
prepared and the resultant polyurethane polymer has good
physical properties.
Bisulfites used in the present invention are more
preferable as a blocking agent used in the textile field
than any known blocking agents, such as phenols, alcohols
and amides, because bisulfites dissociate from the isocyan-
ate groups at a very low temperature and the dissociated
isocyanate groups readily form polyurethane polymers by
heating. Further a since the urethane pre-polymers having
one or more isocyanate groups blocked by bisulfites are
hydroscopic, they can be used in a form of aqueous liquid,
namely an aqueous solution or aqueous emulsion.
A process for the preparation of the aqueous
liquid of the hydroocopic and hea~-active urethane
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pre-polymer having one or more isocyanate groups blocked
by bisulfites used in the present invention is disclosed
in detail in Japanese Patent Application Laid-Open Nos.
155794~75 and 10~395/75 as follows:
(1) According to a conventional methodg a low-molecular-
weight urethane pre-polymer having one or more isocyanate
groups and being substantially free from gel parts is
prepared by reacting at least one of compounds having a
number average molecular weight of 200 to 20,000 and
having active h-ydrogen atoms in both terminals thereof,
with molar excess of a polyisocyanate compound a.nd
optionally a low-molecular-weight chain-extender.
As for the compounds having active hydrogen atoms
in both terminals thereofg there may be exemplified
conventional polyether polyols, polyester polyols and
polyetherester polyols. Among these polyols, the polyols
having an oxyethylene group of 10 to 40 % by weight in the
molecule are preferably used.
As for the polyisocyanate compounds, there may be
: 20 exemplified conventional aliphatic polyisocyanate compounds,
such as hexamethylene diisocyanate, aromatic polyisocyanate
compounds 9 such as diphenylmethane-4,4'-diisocyanate,
aralkyl polyisocyanate compounds, such as xylylene
diisocyanate, and alicyclic polyisocyanate compounds, such
as dicyclohexylmethane-4,4'-diisocyanate.
As for the chain-extenders, there may be exemplified
conventional gIycols~ such as ethylene glycol, 1~4-butane
diol and 1,6-hexane diol~ polyalcohols, such as glycerin,
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1 1~1197
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trimethylolpropane and pentaerythritolg diamines 9 such as
ethylene diamine, hexamethylene diamine and piperazine, and
aminoalcohols, such as monoethanolamine and diethanolamine.
The molar amount of the isocyanate groups per 1 mol of the
active hydrogen atoms (including the active hydrogen atoms
contained in a chain-extender) is more than 1 mol and that
in such a way as to provide an isolated isocyanate group
content of not more than 10 ~ by weight, preferably not
more than 7 % by weight in the obtained pre-polymer.
(2) The urethane pre-polymer obtained in (1) is reacted
as it is or after being diluted with a solvent thereof
with an aqueous solution of bisulfites while stirring the
mixture at a temperature of not higher than 60C for 5
minutes to 1 hour.
As for the bisulfites, there may be preferably
exemplified ammonium bisulfite (NH4HS03), sodium bisulfite
(NaHS03) and potassium bisulfite (K~S03).
The aqueous solution of bisulfites preferably
contains bisulfites of not more than three times isolated
iso~yanate groups in molar amounts and preferably has a
concentration of not less than 15 ~ by weight. As for the
solvents for diluting the pre-polymer, there may be
exemplified dioxane, methyl ethyl ketone, ethyl acetate,
toluene and dimethylformamide.
(3) A water-in-oil or oil-in-water emulsion of the
urethane pre-polymer is obtained according to the above-
men*ioned reaction t2). The obtained emulsion is diluted
with water as it is or after removing the solvent contained
.
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- 14 _
in the emulsion to form an aqueous liquid (an aqueous
solution or oil-in-water emulsion) of the urethane pre-
polymer having a desired concentration. Thereafterg
hydrogen peroxide, organic or inorganic acid is added to
this aqueous liquid for stable storage in an acid state,
preferably at a PH of not more than 5 at 20C.
When the aqueous liquid having a PH of less than 5
is applied to the raised fabricg the polyurethane polymer
formed in the raised fabric has insufficient repulsive
elasticity and color fastness to water of the dyed fabric
is poor. Thereforeg it is preferable to adjust the PH of
the aqueous liquid of the urethane pre-polymer to the range
of 5.0 to 7.09 particularly 6.0 to 6.5 prior to applying the
aqueous liquid to the raised fabric. For adjusting the PH
of the aqueous liquid, inorganic alkaline compounds, such
as sodium bicarbonate, sodium carbonate and sodium
hydroxide are preferably used.
The urethane pre-polymer of the present invention
is applied to the raised fabric in a dry amount of 1 to 20 %9
preferably 3 to 10 ~ by weight based on the weight of the
fabric. When the amount is less than 1 % by weight, the
obtained raised fabric does not have sufficient repulsive
elasticity. On the other hand, when the amount is more
than 2Q ~ by weightg the writing effect of the obtained
raised fabric is poor. For applying the aqueous liquid of
the urethane pre-polymer, there may be a method of impr~g-
nating the raised fabric with the aqueous liquidg a method
of coating the aqueous liquid onto the raised fabric or a
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method of spraying the aqueous liquid on the raised fabric.
The impregnating method is preferable to apply the urethane
pre-polymer throughout the raised fabric uniformly. It is
preferable to use an aqueous liquid of the urethane pre-
S polymer having a pre-polymer concentr~tion within a range
of 1 to 30 % by weight of the liquid.
After applying the aqueous liquid of the urethane
pre-polymer~ the raised fabric is usually dried to remove
moisture at a temperature of about ~0 to 120C for about
1 to lS minutes. The dried raised fabric is heated at a
temperature of 100 to 180C, preferably 110 to 140~C for
about 10 seconds to 15 minutes. Upon heat-treatingg the
urethane pre-polymer in the raised fabric releases bi-
sulfites blocking isocyanate groups to regenarate active
isocyanate groups, and accordingly to form a polyurethane
polymer by a self-cross-linking reaction. When the heat-
treating temperature is lower than 100C, the rate of the
self-cross-linking reaction of the urethane pre-polymer is
slow. On the other h~nd, when the heat-treating temperature
is hi~her than 180C~ the mechanical properties of the
obtained raised fabric tend to be poor. In the case of a
dyed fabric 3 the heat-treating temperature of 110 to 140C
is preferably employed in order to retain good color
fastness.
In the present inventiong it is possible to use a
catalyst to promote the cross-linking reaction of the
urethane pre-polymer. As for the catalysts, there may be
exemplified tertiary amines 3 such as diaza-bicyclooctane
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and organic metal compounds, such as dibutyl tin dilaurate.
Thereafter 9 at least one surface of *he raised
fabric containing the polyurethane polymer is buffed by any
conventional method with a sand roller or sand belt having
sand paper of 40 to 400 mesh size or sand clcth. When
subjected to buffing 9 the state of the raised fibers
which lay flat in one direction fixed by the polyurethane
polymer is randomized and the length of the rais~d fib~rs
is uniformly arrangedg and accordingly the raised fabric
comes to have an excellent writing effect~ feed and
appearance similar to natural suede. If necessary, brushin~
and/or decatizing operations may be performed on the
buffed fabric.
Further, in the present invention, it is possible on
lS or after the process of applying the urethane pre-polymer
to carry out water repellentg water proofing, soil resist~
ant, anti-static, slime imparting, flame resistant and
fire proofing treatments.
The process in accordance with the present invention
employing the urethane pre-polymer has the following
characteristics as compared with conventional methods
using an emulsion or organic solvent solution of a poly-
urethane polymer:
(1) The urethane pre-polymer of the present invention
has a relatively low molecular weight, and accordingly
permeates into the raised fabric uniformly to fully
manifest the excellent effect of the polyurethane polymer,
and hence it is possible to obtain the raised fabric having
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11~1197
excellent repulsive el3sticity and wrinkle recovery.
(2) The aqueous liquid of the urethane pre-pol~mer of the
present invention has a relatively low viscosity, and
accordingly it is possible to obtain the raised fabric
S having excellent writing e~fect and being free from becom-
ing a paper like raised state9 even if the aqueous liquid
is used in a relatively high pre-polymer concentration.
(3) The aqueous liquid of the urethane pre-polymer of
the present invention has excellent aqueous liquid
stability~ and accordingly i5 free from troublesg such as
gumming in the applying process of the raised fabric.
The suede-like raised woven or knitted fabric
obtained in accordance with the present invention has an
excellent writing effectg repulsive elasticity, wrinkle
lS resistance, feel and appearance similar to natural suede.
Accordingly, the suede-like raised woven or knitted fabric
of the present invention has wide varieties of use as
clothing, such as jackets, jumpers, blazers, skirts,
trousers, shorts, slacks, dresses, suits, vests, coats and
~0 glovesg bags~ boots and chair covers.
The following examples are illustrative of the
present invention, but are not to be construed as limiting
the scope of the present invention. In the examples, parts
are on a weight basis.
Example 1
~Preparation of a raised woven fabric]
Hollow composite filaments were prepared in
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11~1197
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accordance with the method disclosed in U.S. Patent No.
4~05192870 The hollow composite filament was composed OI
16 alternately arranged segments of polyethylene tere-
phthalate having an intrinsic viscosity of 0~62 (at 35C
in O~chlorophenol) and poly-E-caproamide having an intrinsic
viscosity o~ 1.30 (at 35C in m-cresol) which were mutually
adhered side-by-side and encompassed a center hollow cavity
and which extended along the longitudinal axis of the
filament to form a tubular bodyg whose schematic cross-
sectional vîew is illustrated in Figure 1.
In Figure 17 the hollow composite filament 1 iscomposed of eight polyamide ~poly-~-caproamide) segments 2 9
eight polyester (polyethylene terephthalate) segments 3 -
and a center hollow cavity 4. In the drawing, the ratio
of the to-tal weight of the polyamide segments to that of
the polyester segments is 1 : 1~ the denier of individual
segments is 0.23 and the denier of the hollow composite
filament is 3.7. The hollow ratio - the ratio by volume
of the hollow cavity to the sum of the volume of the
pGlyamide and polyester segments and the hollow cavity is
8 ~ by volume.
As for the weft yarn~ a single twist filament yarn
of the hollow composite multifilaments (300 deniers/80
filaments) having a twist number of S 120 turnsimeter
(T/m~ was used. As for the warp yarn, a twin filament
yarn (200 deniers) consisting of two 100 denier~24 filament
wooly (false twisted) yarns of polyethylene terephthalate
and having a twist number of S 150 T/m w~s used.
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A 4-ply satin was prepared wi-th these weft and warp
yarns~ the woven density of which was 70 warps/inch and
56 werts/inch.
The resultant woven fabric was relaxed in a hot
water bath at a temperature of 98OC for 30 minutes9 and
dried at a temperature of 120C for 3 minutes. An oiling
agent mainly consisting of mineral oil was applied to the
dried fabric. Thereafter9 one surface of the fabric was
raised 15 times with a wire raising machine having a
plurality of 33 count wires at a running speed of
30 m/minute. The raised fabric was then pre-heat set at
a temperature of 170C for 30 seconds using a pin tenter
type heat setter. ThF filaments textra fine fibers)
constituting the weft yarn of the resultant raised woven
fabric had an average monofilament denier of 0.45.
Thereafter, -the pre-heat set fabric was dyed at a
temperature of 130C for 60 minutes in an aqueous dyeing
bath containing 4 % (based on the weight of the fabric) of
Duranol Blue G (CoI~ No. 63305, tradernark for a disperse
dye produced by I.CI.~, 0.2 mQ/Q of acetic acid, and 1 g/Q
of a dispersing agent mainly containing a condensation
product of naphtnalane sulfonic acid with formamide. The
fabric was then washed with an aqueous solution containing
a nonionic detergent at a temperature of 80C for 20
minutes~ and dried at a temperature of 120C for 3 minutes.
[Preparation o an urethane pre~polymer]
An urethane pre-polymer having isocya~te groups was
prepared by reacting a mixture (the molar ratio of the
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isocyanate groups to the active hydrogen atoms was 2.06)
at a temperature of 100 to 105C for one hour in a stream
of nitrogen gas9 which mixture consists of the following
compounds: (1) 21 parts of a block-copolymerized polyether
diol having a number average molecular weight of 2~400
which was obtained by reacting polypropylene glycol having
a num~er average molecular weight of about 19 200 with
ethylene oxide~ (2) 56 parts of a polyester diol which was
obtained by reacting adipic acidg 1~6-hexane diol and
neopentyl glycol in a molar ratio of 10 : 7 : 4 respectively~
(3) 3 parts of 1~6-hexane diol~ and (4) 20 parts of
hexamethylene diisocyanate.
The isocyanate group and oxyethylene group contents in the
resultant urethane pre-polymer were So02 % and 10.2 % by
lS weight respectively.
After cooling to 40~C~ 20 parts of dioxane was
added to the resultant urethane pre-polymer to form a
solution of the pre-polymer. The obtained solution was
mixed thoroughly with 65 parts of an aqueous solution of
sodium b;sulfite having a concentration of ~5 % by weight
at a temperature of 40C for 30 minutes.
Thereafter, 20~ parts of water and an adequate
amount of hydrogen peroxide were added to the reaction
~ixture to obtain an aqueous solution of the urethane pre-
polymer having a PH of 3 and a concentration of about 30by weight.
[Preparation of a suede-like raised woven fabric~ -
The raised and dyed woven fabric was immersed in a
.
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., . . . . ~. , .. , ~ . ~ , - , . .
. '., , , , ,, . .'. - ~ ' ' '
': '. ' : . ,,' , :' .. ; '., ' . .. . :.:: . :.. :: . . ~ . ' ' , :
, ' ' ' . ' ' .... ' ! ' ' .. . . ' ' ' . ' . .. .
llG1~97
- 21 -
8 % by weight aqueous solution of the abovementioned
urethane pre-polymer (the pH was adjusted to 6.0 with
sodiu~, bicarbonate) 9 and then squeezed to a pick-up ratio
of 70 % based on the weight of the fabric. The squee~ed
fabric was dried at a temperature of 100C for 3 minutes
and heat-treated at a temperature of 140~C for 30 seconds.
The raised surface of the woven fabric was then buffed one
time by a roller sander machine with sand paper of 100
mesh size9 followed by brushing.
T~le obtained fabric had excellent repulsive
elasticity (bending resilience of about 65 to 80 ~)9
excellent wrinkle recovery9 excellent writing effect and
suede-like touch. The physical properties of this fabric
are shown in Table 1. Particularlyg this fabric had
lS excellent repulsive elasticity~ exceilent wrinkle resist-
ance and excellent writing effect as compared with a
raised woven fabric obtained in accordance with Comparative
1.
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- 24 _
Footnotes from Table 1:
*1~ Method of measuring bending stiffness and resilience~
~Figure 3)
A test piece 11 having a length of 5 cm and a width of
2 cm is cut off from the raised fabric. The test
piece 11 is set in a sample holder 12 fixed on the
cross head 13 of an Instron Tensile Tester as shown in
Figure 3-a.
The distance between the wedge 8 of load cell 9 and
the sample holder 12 is 2 cm as shown in Figure 3-a.
The sample holder l2 is moved upwards by 1.5 cm from
the original position as shown in Figure 3-b and
thereafter is moved downwards by 1.5 cm.
The relationship between the distance moved and the
repulsive force of the test piece is recorded by the
recorder 10 of the Instron Tensile Tester, and a
chart as shown in Figure 3-c is obtained.
In Figure 3-c, bending stiffness is read as a gram
value at Pl' and bending resilience is calculated from
the repulsive forces at Hl' and H2' using the follow-
ng equation:
repulsive force a-t H '
Bending resilience = - - 2 x 100 (%)
repulsive force at Hl'
(Ho is the middle of the distance between P0 and Pl").
*2/ Method of measuring wrinkle recovery
A test piece having a length of 25 cm (weft) and a
width of 8 cm (warp) is cut off from the raised fabric.
. :
.
: , , "
97
- 25 -
The both ends of the test piece are sewed together into
a sleeve form having a circumference of 24 cm. The
sleeve form test piece is fitly put on a cylinder
having a circumference of 24 cm which is vertically
placed on a horizontal stand.
The sleeve form test piece is pressed for 30 minutes
with a ring form load of 4 Kg which fits the cylinder.
After removing the load and unsewing the thread, the
test piece is left for 3 hours. Thereupon the degree
of wrinkles formed on the test piece is evaluated by
the naked eyes.
5 - wrinkles scarcely occurred
4 - wrinkles slightly occurred
3 - wrinkles appreciably occurred
2 - wrinkles considerably occurred
1 - wrinkles exorbitantly occurred
*3t Chan~e of appearance of the raised fabric evaluated by
the naked eyes when two surfaces of the fabric were
rubbed against each other 5000 times:
~0 excellent - change of appearance scarcely occurred
good - change of appearance slightly occurred
poor - change of appearance considerably
occurred
- - : .. .. . . . : . .
. : :
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- 26 -
*4/ Grade evaluated by the naked eyes:
5 - pilling scarcely occurred
4 ~ pilling slightly occurred
3 - pilling app-l~eciably occurred
S 2 - pilling considerably occurred
ll - pilling exorbitantly occurred
*5~ Writing effect evaluated by the naked eyes (when a
finger is passed on the surface of the raised fabric
having naps~ the naps are along the direction of the
finger pass):
excellent - finger-marks appear remarkably
good - finger-marks appear considerably
poor - finger-marks appear slightly
.-~
,
1197
- 27 -
Comparative 1
A suede-like raised woven fabric was prepared by the
same procedure as in Example 1~ except that an 8 % by weight
aqueous emulsion of a polyurethane polymer (a reaction
product of diphenylmethane-4949-diisocyanate, polyethylene
glycol and 1,4-butane diol3 was used in the place of the
urethane pre-polymer of Example 1.
The physical properties of the obtained fabric are
shown in Table 1. This fabric had low repulsive elasticity
and was poor in wrinkle resis-tance.
Examples 2 to 49 Com~aratives 2 and 3
Suede-like raised woven fabrics were prepared by the
same procedure as in Example 1~ except for varying the
amounts of the urethane pre-polymer applied to the respec-
tive raised woven fabrics.
The physical properties of the obtained fabrics are
shown in Table 1. The fabrics in Example 2 (2.0 % by weight)g
Example 3 (10 % by weight~ and Example 4 (15 % by weight)
had excellent repulsive elasticity~ excellent wrinkle
resistance and excellent writing effect.
On the other hand, the fabric in comparative 2
(0.5 % by weight) which was out of the scope of the present
invention had neither sufficient repulsive elasticity nor
sufficient wrinkle recovery. The fabric in Comparatîve 3
(22 % by weight) was poor in ~riting effect.
-
,
11~11~37
- 28 -
Example 5
Islands-i.n-sea type composite filaments were
prepared in accordance with the method disclosed in U.S.
Patent No. 39562~374. The islands-in-sea type composite
filament was composed of island components of polyethylene
tere.phthalate having an intrinsic viscosity of 0.62 (at
35C in O-chlorophenol) and a sea component of polystyrene
having a number average molecular weight of about 50~000
whose schematic cross-sectional view is illustrated in
Figure 2.
In Figure 2, the islands-in-sea type composite
filament 5 is composed of island (polyethylene tere-
phthalate) components 6 and a sea (polystyrene) component
7. In the drawing 9 the islands-in-sea type composite
filament has eight island components, the ratio of the
total weight of the island components to that of the sea
component is ~ : 4, the denier of individual island
components is 0.24 and the denier of the islands-in-sea
type composite ~ilament is 3.8.
As for the weft yarn~ a single twist filament yarn
of the islands-in-sea type composite multifilaments
(300 deniers/80 filaments) having a twist number of
S 120 T/m was used. As for the warp yarn, a twin filament
yarn (200 deniers) consisting of two 100 denier/24 filament
woolly (false twisted) yarns of polyethylene terephthalate
and having a twist number of S 150 T/m was used.
A 4-ply satin was prepared with these weft and warp
yarns, the woven density of which was 77 warps/inch and
.
. .
'
ll~li97
- 29 -
59 wefts/inch.
The resultant woven fabric was relaxed in z hot
water bath at a temperature of 100C for 30 minutes9 and
dried at a temperature of 120C for 3 minutes. Thereafter~
the woven fabric was washed 5 times with trichloroethylene
to remove the sea component of polystyrene. According to
the same procedure as described in Example 19 the fabric
was then subjected to the processes of raising, dyeing,
impregnatinga heat-treatingg buffing and brushing to obtain
a suede-like raised woven fabric.
The obtained fabric had excellent repulsive
elasticityg excellent wrinkle recovery9 excellent writing
effect and fine suede-like touch. The physical properties
of this fabric are shown in Table 1.
Example 6
A tricot having a weight of 120 g/m was prepared by
using as a front yarn, a single twist filament yarn
(S 120 T/m) of the hollow composite multifilaments (75
deniers/20 filaments) as disclosed in Example 1, and as a
back yarn, a filament yarn (30 deniersJ12 filaments) of
polyethylene terephthalate. The tricot was then treated by
the same procedure as in Example 1 to obtain a suede-like
raised knitted fabric.
The resultant fabric had excellent repulsive
elasticityg excellent wrinkle recovery and excellent
writing effect.
:
,: - ' ' . :
., . : , :
. . : , , - ' ~
: : .-
- : - :
-
1137
~ 30 -
Example 7
A double faced woven fabric having a 4-ply satin
structure in both surfaces and having a wei~ht of 250 g/m2
was prepared by using as a warp yarn, a 100 denier/24
filament woolly (false twisted) yarn of polyethylene
terephthalate (S 150 T/m), and as a weft yarn for both the
surface and back surface a a single twist filament yarn
~S 150 T/m) of the hollow composite multifilaments (150
deniers/40 filaments) as disclosed in Ex~mple 1. The
surface of the fabric was raised 15 times and the back
surface of the fabric was raised 5 times with a wire
raising machine having a plurality of 33 count wires at a
running speed of 30 m/minute. The filaments (extra fine
fibers) constituting the weft yarns of the surface and
back surface of the resultant fabric had an average
monofilament denier of 0.45 and 0.72 respectively. The
raised fabric was then treated according to the same
procedure as in Example 1 to obtain a suede-like raised
woven fabric.
The resultant fabric had excellent repulsive
elasticity, excellent wrinkle recovery and excellent
writing effect, and was also superior in a~pearance to
the fabric obtained in Example 1, because the woven organi-
zation of the back surface was covered enough with raised
fibers.
Poly-~-caproamide was melt-spun at a temperature of
..
- , . . ~:
11~31197
~ 31 -
260C at a high spinning speed of 3~500 m/minute to
obtain a multifilament yarn consisting of 40 deniers/57
filaments (the monofilament denier is 0.7). ~ 4-ply
satin having a woven density of 70 warps/inch and 5~
wefts/inch was prepared by using as a weft yarn9 a twist
~yarn ~a twist number of ~ 120 T/m) formed by twisting
five multifilament yarns9 and as a warp yarn a a twin
filament yarn (140 denier) consisting of two 70 denier/24
filament woolly (false twisted) yarns of poly-~-caproamide
and having a twist number of S 150 T/m.
The resultant woven fabric was relaxed in a hot
water batll at a temperature of 80C for 20 minutes, and
dried at a temperature of 120C for 3 minutes. An oiling
agent mainly consisting of mineral oil was applied to the
dried fabric. Thereafter~ one surface of the fabric was
raised 10 times with a wire raising machine having a
plurality of 33 count wires at a running speed of 30 m/
minute~ The raised fabric was then pre-heat set at a
temperature of 160C for 30 seconds using a pin tenter
~0 type heat setter.
Thereafter a the pre-heat set fabric was dyed at a
temperature of 100C for 40 minutes in an aqueous dyeing
bath containing 3 ~ (based on the weight of the fabric) of
Suminol Milling Brilliant Red B (C.I. No. 18134 a trademark
for an acid dye produced by Sumitomo Chemical Co.) and
2 mQ/Q of acetic acid. The fabric was then wasned with an
aqueous solution containing a nonionic detergent at a
temperature of 70C for 20 minutes, and dried at 2
.
. . ' " . ' . -
- . ' - . ' ' ' .
. . . : -:
.
3L1~1~97
32 ~
temperature of 120C for 3 minutes. According to the same
procedure as in Example 1, the dyed fabric was then
subjected to the processes of impregnating9 heat-treating~
buffing and brushing to obtain a suede-like raised woven
fabric.
The obtained fabric had excellent repulsive
elasticity~ excellent wrinkle recovery, excellent writing
effect and fine suede-like touch.
Example 9
tPreparation of an urethane pre-polymer]
An urethane pre-polymer having isocyanate groups was
prepared by reacting a mixture (the molar ratio of the
isocyanate groups to the active hydrogen atoms was 1~60)
at a temperatre of 95 to 100C for one hour in a stream
of nitrogen gas 9 which mixture consists of the following
compounds: (1) 36 parts of a polyester diol which was
obtained by reacting adipic acid 3 1,6-hexane diol and
neopentyl glycol in a molar ratio of 4 : 3 : 2 respec-
tively~ ~2) 41 parts of polyethylene glycol having a
number average molecular weight of about 1,000; and (3) 23
parts of xylylene diisocyanate. The isocyanate group and
oxyethylene group contents in the resultant urethane
pre-polymer were 3.76 ~ and 39.6 ~ by weight respectively.
After cooling to 40C, the resultant urethane
pre-polymer was mixed thoroughly with S0 parts of an
a~ueous solution of potassium bisulfite having a concent- -
ration of 30 % by weight at a temperature of 40C for
. . ,
.
.
': ' ' ' ', ' ,- ' ' ' ~: ' '
:' : . ' -
,
~lQ1197
- 33 -
20 minutes. Thereafter, 233 parts of water and an adequate
amount of hydrogen peroxide and tartaric acid were added
to the reaction mixture to obtain an aqueous emulsion of
the urethane pre-polymer having a PH of 2 and a concentra-
tion of about 30 % by weight.tPreparation of a suede-like raised woven fabric]
The raised and dyed woven fabric obtained in
Example 1 was immersed in a 8 % by weight aqueous emulsion
of the abovementioned urethane pre-polymer (the PH was
adjusted to 6.5 with sodium carbonate)9and then squeezed
to a pick-up ratio of 70 ~ based on the weight of the
fabric. The squeezed fabric was dried at a temperature o~
100C for 3 minutes and heat-treated at a temperature of
120C for 2 minutes. The raised surface of the woven
lS fabric was then buffed one time by a roller sander machine
with sand paper of 100 mesh size, followed by brushing.
The obtained fabric had excellent repulsive elastici
elasticity, excellent wrinkle recovery, excellent writing
effect and fine suede-like touch. The physical properties
of this fabric are shown in Table 1.
: . . . -, . -
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