U.S. patent application number 10/542048 was filed with the patent office on 2006-09-21 for modified cross-section polyester fibers.
Invention is credited to Keijiro Hattori, Mie Kamiyama, Katushi Kikuchi, Tsuyoshi Masuda, Nobuyoshi Miyasaka, Tomoo Mizumura, Suguru Nakajima, Hiroyuki Osaka, Ryoji Tsukamoto.
Application Number | 20060210797 10/542048 |
Document ID | / |
Family ID | 32896192 |
Filed Date | 2006-09-21 |
United States Patent
Application |
20060210797 |
Kind Code |
A1 |
Masuda; Tsuyoshi ; et
al. |
September 21, 2006 |
Modified cross-section polyester fibers
Abstract
Polyester fibers having a deformed section are produced from a
polyester polymer which is obtained by polycondensing an aromatic
dicarboxylate ester in the presence of a catalyst containing a
mixture of a Ti component (A) comprising at least one a titanium
alkoxide or a reaction product thereof with a specific carboxylic
acid or its anhydride with a P compound component (B) represented
by the following general formula (III) and/or a reaction product of
a Ti compound component (C) with a P compound component (D)
represented by the following general formula (IV). The obtained
fibers have a favorable color tone and excellent qualities without
showing fluffing. ##STR1##
Inventors: |
Masuda; Tsuyoshi;
(Matsuyama-shi, JP) ; Kamiyama; Mie;
(Matsuyama-shi, JP) ; Mizumura; Tomoo;
(Matsuyama-shi, JP) ; Miyasaka; Nobuyoshi;
(Osaka-shi, JP) ; Tsukamoto; Ryoji;
(Matsuyama-shi, JP) ; Hattori; Keijiro;
(Chiyoda-ku, JP) ; Nakajima; Suguru;
(Matsuyama-shi, JP) ; Kikuchi; Katushi;
(Matsuyama-shi, JP) ; Osaka; Hiroyuki;
(Matsuyama-shi, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Family ID: |
32896192 |
Appl. No.: |
10/542048 |
Filed: |
December 25, 2003 |
PCT Filed: |
December 25, 2003 |
PCT NO: |
PCT/JP03/16766 |
371 Date: |
December 6, 2005 |
Current U.S.
Class: |
428/397 ;
428/398; 428/399; 428/400 |
Current CPC
Class: |
D01F 6/62 20130101; Y10T
428/2973 20150115; Y10T 428/2978 20150115; C08G 63/85 20130101;
Y10T 428/2975 20150115; Y10T 428/2976 20150115; D01D 5/253
20130101; C08K 5/51 20130101; C08G 63/181 20130101 |
Class at
Publication: |
428/397 ;
428/398; 428/399; 428/400 |
International
Class: |
D02G 3/00 20060101
D02G003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 14, 2003 |
JP |
2003-5561 |
Claims
1. Modified cross-section polyester fibers comprising, as a
principal component, a polyester polymer and having a modified
cross-section, wherein the polyester polymer is produced by
polycondensation of an aromatic dicarboxylate ester in the presence
of a catalyst, the catalyst comprises at least one ingredient
selected from among mixture (1) and reaction product (2) below, the
mixture (1) is a mixture of the following components (A) and (B):
(A) a titanium compound component comprising at least one compound
selected from the group consisting of: (a) titanium alkoxides
represented by the following general formula (I): ##STR11##
[wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each independently
represent one species selected from among alkyl groups having 1 to
20 carbon atoms and phenyl groups, m represents an integer of 1-4,
and when m is an integer of 2, 3 or 4, the two, three or four
R.sup.2 and R.sup.3 groups may be the same or different], and (b)
reaction products of titanium alkoxides of general formula (I)
above with aromatic polyvalent carboxylic acids represented by the
following general formula (II): ##STR12## [wherein n represents an
integer of 2-4] or their anhydrides, and (B) a phosphorus compound
component comprising at least one compound represented by the
following general formula (III): ##STR13## [wherein R.sup.5,
R.sup.6 and R.sup.7 each independently represent alkyl groups
having 1 to 4 carbon atoms, and X represents at least one species
selected from among --CH.sub.2-- group and --CH.sub.2(Y) group
(where Y represents phenyl group)], the mixture (1) for the
catalyst is used with a mixing ratio such that the ratio (%)
M.sub.Ti of the millimoles of titanium element in the titanium
compound component (A) with respect to the number of moles of the
aromatic dicarboxylate ester and the ratio (%) Mp of the millimoles
of phosphorus element in the phosphorus compound component (B) with
respect to the number of moles of the aromatic dicarboxylate ester
satisfy the following expressions (i) and (ii):
1.ltoreq.Mp/M.sub.Ti.ltoreq.15 (i) 10.ltoreq.Mp+M.sub.Ti.ltoreq.100
(ii), and the reaction product (2) is the reaction product of the
following components (C) and (D): (C) a titanium compound component
comprising at least one compound selected from the group consisting
of: (c) titanium alkoxides represented by formula (I) above and (d)
reaction products of titanium alkoxides of general formula (I)
above with aromatic polyvalent carboxylic acids represented by
general formula (II) above or their anhydrides, and (D) a
phosphorus compound component comprising at least one phosphorus
compound represented by the following general formula (IV):
##STR14## [wherein R.sup.8 represents alkyl groups having 1 to 20
carbon atoms or aryl groups having 6 to 20 carbon atoms, and p
represents an integer of 1 or 2].
2. The modified cross-section polyester fibers according to claim
1, wherein component (A) of the mixture (1) for the catalyst and
component (C) of the reaction product (2) for the catalyst contain
the respective titanium alkoxide (a) and titanium alkoxide (c) each
in a reaction molar ratio in the range of 2:1 to 2:5 with respect
to the aromatic polyvalent carboxylic acid represented by general
formula (II) or its anhydride.
3. The modified cross-section polyester fibers according to claim
1, wherein in the reaction product (2) for the catalyst, the
reaction ratio of component (D) with respect to component (C) is in
the range of 1:1 to 3:1, in terms of the ratio of the moles of
phosphorus atoms in component (D) to the moles of titanium atoms in
component (C) (P/Ti).
4. The modified cross-section polyester fibers according to claim
1, wherein the phosphorus compound of general formula (IV) used in
the reaction product (2) for the catalyst is selected from among
monoalkyl phosphates.
5. The modified cross-section polyester fibers according to claim
1, wherein the aromatic dicarboxylate ester is a diester produced
by transesterification of an aromatic dicarboxylic acid dialkyl
ester and an alkylene glycol ester, in the presence of a titanium
compound-containing catalyst.
6. The modified cross-section polyester fibers according to claim
1, wherein the aromatic dicarboxylic acid is selected from among
terephthalic acid, 1,2-naphthalenedicarboxylic acid, phthalic acid,
isophthalic acid, diphenyldicarboxylic acid and
diphenoxyethanedicarboxylic acid, and the alkylene glycol is
selected from among ethylene glycol, butylene glycol, trimethylene
glycol, propylene glycol, neopentyl glycol, hexanemethylene glycol
and dodecanemethylene glycol.
7. The modified cross-section polyester fibers according to claim
1, wherein the lateral cross-section of the single fiber is a flat
shape, and the flat shape is a form with 3-6 round cross-sectional
shapes joined in the lengthwise direction.
8. The modified cross-section polyester fibers according to claim
7, which comprises inorganic particles at 0.2-10 wt % based on the
fibers weight.
9. The modified cross-section polyester fibers according to claim
7, wherein in the lateral cross-section of the fiber, the flatness
represented by A/B as the ratio of the width A of the long axis to
the maximum width B of the short axis perpendicular to the long
axis B is 3-6.
10. The modified cross-section polyester fibers according to claim
7, wherein in the lateral cross-section of the single fiber, the
irregularity represented by B/C as the ratio of the maximum width B
of the short axis to the minimum width C (minimum width at the
joints of the round cross-sectional shapes) is larger than 1 and
smaller than 5.
11. The modified cross-section polyester fibers according to claim
1, wherein the lateral cross-section of the single fiber comprises
a core and 3-8 fins protruding outward from the core, and the
protrusion coefficient as defined by formula (iii) below is between
0.3 and 0.7. Protrusion coefficient=(a.sub.1-b.sub.1)/a.sub.1 (iii)
[where a.sub.1 represents the length from the center of an
inscribed circle in the inner wall of the single fiber
cross-section to the tip of the fin, and b.sub.1 represents the
radius of the inscribed circle in the inner wall of the fiber
cross-section.]
12. The modified cross-section polyester fibers according to claim
11, wherein the fiber crystallinity is no greater than 30%.
13. The modified cross-section polyester fibers according to claim
11, wherein the fiber boiling water shrinkage ratio is 15-70%.
14. The modified cross-section polyester fibers according to claim
1, wherein the polyester single fiber comprises a core and multiple
fins protruding in a radial fashion from the core along the
lengthwise direction of the core, and the single fibers with
cross-sectional shapes satisfying all of the following
relationships (iv) to (vi) are subjected to alkali reduction
treatment to separate at least some of the fins from the cores.
1/20.ltoreq.S.sub.B/S.sub.A.ltoreq.1/3 (iv)
0.6.ltoreq.L.sub.B/D.sub.A.ltoreq.3.0 (v)
W.sub.B/D.sub.A.ltoreq.1/4 (vi) (where S.sub.A represents the
cross-sectional area of the core, D.sub.A represents the core
diameter if the cross-section is a circle or the circumscribed
circle diameter if it is not a circle, and S.sub.B, L.sub.B and
W.sub.B represent the cross-sectional area, maximum length and
maximum width of the fins, respectively.)
15. The modified cross-section polyester fibers according to claim
14, wherein a compound having a compatibility parameter .chi.
represented by relationship (vii) below of 0.1-2.0 is included in
the polyester fiber prior to alkali treatment at 0.5-5.0 wt % with
respect to the polyester fiber weight.
.chi.=(V.sub.a/RT)(.delta.a-.delta.b).sup.2 (vii) (where V.sub.a
represents the molar volume (cm.sup.3/mol) of the polyester, R
represents the gas constant (J/molK), T represents the absolute
temperature (K) and .delta.a and .delta.b represent the solubility
parameters (J.sup.1/2/cm.sup.3/2) of the polyester and compound,
respectively.)
16. The modified cross-section polyester fibers according to claim
1, wherein the lateral cross-section of the single fiber is a shape
comprising a triangular shaped section and a protrusion extending
from one vertex of the triangular shape, where both of the
following relationships (viii) and (ix) are satisfied, and having a
hollow portion in the triangular shaped section constituting 3-15%
thereof. 0.7.ltoreq.L1/L2.ltoreq.3.0 (viii)
3.0.ltoreq.h2/h1.ltoreq.10.0 (ix) (where L1 represents the distance
from the connection point between the triangular shaped section and
the protrusion to the end of the protrusion, L2 represents the
distance between the connection point between the triangular shaped
section and the protrusion and the side of the triangular shaped
section opposite the connection point, h1 represents the width of
the protrusion and h2 represents the length of the side of the
triangular shaped section opposite the connection point between the
triangular shaped section and the protrusion.)
17. The modified cross-section polyester fibers according to claim
16, wherein an organic sulfonic acid metal salt represented by
general formula (V) below is included at 0.5-2.5 wt % with respect
to the weight of the polyester fibers. R.sup.9SO.sub.3M (V) (where
R.sup.9 represents alkyl group having 3 to 30 carbon atoms or aryl
or alkylaryl group having 7 to 40 carbon atoms, and M represents an
alkali metal or alkaline earth metal.)
Description
TECHNICAL FIELD
[0001] The present invention relates to modified cross-section
polyester fibers. More specifically, it relates to modified
cross-section polyester fibers produced using a polyester polymer
with satisfactory color tone and excellent moldability.
BACKGROUND ART
[0002] Polyester polymers, and particularly polyethylene
terephthalate, polyethylene naphthalate, polytrimethylene
terephthalate and polytetramethylene terephthalate, exhibit
excellent mechanical, physical and chemical performance and are
therefore widely used for fibers, films and other molded
products
[0003] Such polyester polymers, for example polyethylene
terephthalate, are usually produced by first preparing an ethylene
glycol ester of terephthalic acid and/or a lower polymer thereof
and then heating it under reduced pressure in the presence of a
polymerization catalyst for reaction to the desired degree of
polymerization. Other polyesters are produced by similar
processes.
[0004] It is known that the type of polycondensation catalyst used
has a major effect on the quality of the resulting polyester, and
antimony compounds are most widely used as polycondensation
catalysts for polyethylene terephthalate.
[0005] A problem is associated with the use of antimony compounds,
however, because prolonged continuous melt spinning of polyesters
results in accumulated adhesion of foreign matter around the
spinneret hole (hereinafter referred to simply as "spinneret
adhesion" and redirection of the molten polymer flow (bending),
which ultimately lead to fluff and yarn breakage or mottling of the
physical properties of filaments during the spinning and drawing
steps.
[0006] Particularly when it is attempted to produce filaments with
modified lateral cross-sections by melt spinning, the complex shape
of the spinneret hole means that foreign matter on the spinneret
has a greater influence on the discharge state of the molten
polymer, while problems such as fluff and yarn breakage also occur
during spinning.
[0007] As means of solving these problems, there have been
disclosed the use of the reaction products of titanium compounds
and trimellitic acid as polyester production catalysts (for
example, see Japanese Examined Patent Publication SHO No. 59-46258)
and the use of the reaction products of titanium compounds and
phosphorous acid esters as polyester production catalysts (for
example, see Japanese Unexamined Patent Publication SHO No.
58-38722). While these methods do enhance the molten heat stability
of polyesters to some degree, the enhancing effect is inadequate
and the obtained polyester polymers are in need of color tone
improvement.
[0008] There have also been proposed titanium compound/phosphorus
compound complexes as polyester production catalysts (for example,
see Japanese Unexamined Patent Publication HEI No. 7-138354).
However, although this method enhances the molten heat stability to
some degree, the effect is inadequate and the obtained polyesters
are in need of color tone improvement.
DISCLOSURE OF THE INVENTION
[0009] It is a first object of the invention to solve the
aforementioned problems of the prior art by providing modified
cross-section polyester fibers having satisfactory color tone, no
fluff and high quality. This object is achieved by the following
modified cross-section polyester fibers.
[0010] The modified cross-section polyester fibers comprising, as
principal component, a polyester polymer and having a modified
cross-section,
[0011] wherein
[0012] the polyester polymer is produced by polycondensation of an
aromatic dicarboxylate ester in the presence of a catalyst,
[0013] the catalyst comprises at least one ingredient selected from
among mixture (1) and reaction product (2) below,
[0014] the mixture (1) is a mixture of the following components (A)
and (B):
[0015] (A) a titanium compound component comprising at least one
compound selected from the group consisting of:
[0016] (a) titanium alkoxides represented by the following general
formula (I): ##STR2## [wherein R.sup.1, R.sup.2, R.sup.3 and
R.sup.4 each independently represent one species selected from
among alkyl groups having 1 to 20 carbon atoms and phenyl groups, m
represents an integer of 1-4, and when m is an integer of 2, 3 or
4, the two, three or four R.sup.2 and R.sup.3 groups may be the
same or different], and
[0017] (b) reaction products of titanium alkoxides of general
formula (I) above with aromatic polyvalent carboxylic acids
represented by the following general formula (II): ##STR3##
[wherein n represents an integer of 2-4] or their anhydrides,
and
[0018] (B) a phosphorus compound component comprising at least one
compound represented by the following general formula (III):
##STR4## [wherein R.sup.5, R.sup.6 and R.sup.7 each independently
represent alkyl groups having 1 to 4 carbon atoms, and X represents
at least one species selected from among --CH.sub.2-- group and
--CH.sub.2(Y) group (where Y represents phenyl group)],
[0019] the mixture (1) for the catalyst is used with a mixing ratio
such that the ratio (%) M.sub.Ti of the millimoles of titanium
element in the titanium compound component (A) with respect to the
number of moles of the aromatic dicarboxylate ester and the ratio
(%) M.sub.p of the millimoles of phosphorus element in the
phosphorus compound component (B) with respect to the number of
moles of the aromatic dicarboxylate ester satisfy the following
expressions (i) and (ii): 1.ltoreq.M.sub.p/M.sub.Ti.ltoreq.15 (i)
10.ltoreq.M.sub.p+M.sub.Ti.ltoreq.100 (ii),
[0020] and reaction product (2) is the reaction product of the
following components (C) and (D):
[0021] (C) a titanium compound component comprising at least one
compound selected from the group consisting of:
[0022] (c) titanium alkoxides represented by formula (I) above
and
[0023] (d) reaction products of titanium alkoxides of general
formula (I) above with aromatic polyvalent carboxylic acids
represented by general formula (II) above or their anhydrides,
and
[0024] (D) a phosphorus compound component comprising at least one
phosphorus compound represented by the following general formula
(IV): ##STR5## [wherein R.sup.8 represents alkyl groups having 1 to
20 carbon atoms or aryl groups having 6 to 20 carbon, and p
represents an integer of 1 or 2].
[0025] Component (A) of the mixture (1) for the catalyst and
component (C) of the reaction product (2) for the catalyst in the
modified cross-section polyester fibers of the invention preferably
contain the respective titanium alkoxide (a) and titanium alkoxide
(c) each in a reaction molar ratio in the range of 2:1 to 2:5 with
respect to the aromatic polyvalent carboxylic acid represented by
general formula (II) or its anhydride.
[0026] In the reaction product (2) for the catalyst of the modified
cross-section polyester fibers of the invention, the reaction ratio
of component (D) with respect to component (C) is preferably in the
range of 1:1 to 3:1, in terms of the ratio of the moles of
phosphorus atoms in component (D) to the moles of titanium atoms in
component (C) (P/Ti).
[0027] The phosphorus compound of general formula (IV) used in the
reaction product (2) for the catalyst in the modified cross-section
polyester fibers of the invention is preferably selected from among
monoalkyl phosphates.
[0028] The aromatic dicarboxylate ester in the modified
cross-section polyester fibers of the invention is preferably a
diester produced by transesterification of an aromatic dicarboxylic
acid dialkyl ester and an alkylene glycol ester, in the presence of
a titanium compound-containing catalyst.
[0029] The aromatic dicarboxylic acid in the modified cross-section
polyester fibers of the invention is preferably selected from among
terephthalic acid, 1,2-naphthalenedicarboxylic acid, phthalic acid,
isophthalic acid, diphenyldicarboxylic acid and
diphenoxyethanedicarboxylic acid, and the alkylene glycol is
preferably selected from among ethylene glycol, butylene glycol,
trimethylene glycol, propylene glycol, neopentyl glycol,
hexanemethylene glycol and dodecanemethylene glycol.
[0030] It is a second object of the invention to provide, in
addition to the first object, modified cross-section polyester
fibers which produce cloths having no sticky feel and excellent
softness, anti-penetration property, low air permeability, water
absorption and wear resistance. This object is achieved by the
following modified cross-section polyester fibers.
[0031] Specifically, these are modified cross-section polyester
fibers comprising as the principal component a polyester polymer
obtained by polycondensation in the presence of the aforementioned
specific catalyst, wherein the lateral cross-sectional shape of
each single fiber is flat, and the flat shape is a form with 3-6
round cross-sectional shapes joined in the lengthwise
direction.
[0032] The modified cross-section polyester fibers preferably
comprise inorganic particles at 0.2-10 wt %.
[0033] In the lateral cross-section of the modified cross-section
polyester fibers, the flatness represented by A/B as the ratio of
the width A of the long axis to the maximum width B of the short
axis perpendicular to the long axis B is preferably 3-6.
[0034] In the lateral cross-section of the modified cross-section
polyester fibers, the irregularity represented by B/C as the ratio
of the maximum width B of the short axis to the minimum width C
(minimum width at the joints of the round cross-sectional shapes)
is preferably larger than 1 and smaller than 5.
[0035] It is a third object of the invention to provide, in
addition to the first object, modified cross-section polyester
fibers with excellent water absorption and quick-drying properties.
This object is achieved by the following modified cross-section
polyester fibers.
[0036] Specifically, these are modified cross-section polyester
fibers comprising as the principal component a polyester polymer
obtained by polycondensation in the presence of the aforementioned
specific catalyst, wherein 3-8 fins protrude outward from the fiber
cross-section core in the lateral cross-section of each single
fiber, and the protrusion coefficient as defined by formula (iii)
below is between 0.3 and 0.7. Protrusion
coefficient=(a.sub.1-b.sub.1)/a.sub.1 (iii) [Here, a.sub.1
represents the length from the center of an inscribed circle in the
inner wall of the fiber cross-section to the tip of the fin, and
b.sub.1 represents the radius of the inscribed circle in the inner
wall of the fiber cross-section.]
[0037] The fiber crystallinity of the modified cross-section
polyester fibers is preferably no greater than 30%.
[0038] The fiber boiling water shrinkage ratio of the modified
cross-section polyester fibers is preferably 15-70%.
[0039] It is a fourth object of the invention to provide, in
addition to the first object, modified cross-section polyester
fibers which produce cloths which are bulky and have a soft hand.
This object is achieved by the following modified cross-section
polyester fibers.
[0040] Specifically, these are modified cross-section polyester
fibers comprising as the principal component a polyester polymer
obtained by polycondensation in the presence of the aforementioned
specific catalyst, wherein the lateral cross-section of each single
fiber comprises a core and multiple fins protruding in a radial
fashion from the core along the lengthwise direction of the core,
and the polyester fibers satisfying all of the following
relationships (iv) to (vi) are subjected to alkali reduction
treatment to separate at least some of the fins from the cores.
1/20.ltoreq.S.sub.B/S.sub.A.ltoreq.1/3 (iv)
0.6.ltoreq.L.sub.B/D.sub.A.ltoreq.3.0 (v)
W.sub.B/D.sub.A.ltoreq.1/4 (vi) (Here, S.sub.A represents the
cross-sectional area of the core, D.sub.A represents the core
diameter if the cross-section is a circle or the circumscribed
circle diameter if it is not a circle, and S.sub.B, L.sub.B and
W.sub.B represent the cross-sectional area, maximum length and
maximum width of the fins, respectively.)
[0041] In the modified cross-section polyester fibers described
above, a compound having a compatibility parameter .chi.
represented by relationship (vii) below of 0.1-2.0 is preferably
included in the polyester fiber prior to alkali treatment at
0.5-5.0 wt % with respect to the polyester fiber weight.
.chi.=(V.sub.a/RT)(.delta.a-.delta.b).sup.2 (vii) (Here, V.sub.a
represents the molar volume (cm.sup.3/mol) of the polyester, R
represents the gas constant (J/molK), T represents the absolute
temperature (K) and .delta.a and .delta.b represent the solubility
parameters (J.sup.1/2/cm.sup.3/2) of the polyester and compound,
respectively.)
[0042] It is a fifth object of the invention to provide, in
addition to the first object, modified cross-section polyester
fibers which produce a silky cloth having a rough squeaky feel, an
excellent bulging feel, flexibility and a lightweight feel, with no
dye spots. This object is achieved by the following modified
cross-section polyester fibers.
[0043] Specifically, these are modified cross-section polyester
fibers comprising as the principal component a polyester polymer
obtained by polycondensation in the presence of the aforementioned
specific catalyst, wherein the lateral cross-sectional shape of a
single fiber is a shape comprising a triangular shaped section and
a protrusion extending from one vertex of the triangular shape,
where both of the following relationships (viii) and (ix) are
satisfied, and having a hollow portion in the triangular shaped
section constituting 3-15% thereof. 0.7.ltoreq.L1/L2.ltoreq.3.0
(viii) 3.0.ltoreq.h2/h1.ltoreq.10.0 (ix) (Here, L1 represents the
distance from the connection point between the triangular shaped
section and the protrusion to the end of the protrusion, L2
represents the distance between the connection point between the
triangular shaped section and the protrusion and the side of the
triangular shaped section opposite the connection point, h1
represents the width of the protrusion and h2 represents the length
of the side of the triangular shaped section opposite the
connection point between the triangular shaped section and the
protrusion.)
[0044] An organic sulfonic acid metal salt represented by general
formula (V) below is preferably included in the modified
cross-section polyester fibers at 0.5-2.5 wt % with respect to the
weight of the polyester fiber. R.sup.9SO.sub.3M (V) (Here, R.sup.9
represents alkyl groups having 3 to 30 carbon atoms or aryl or
alkylaryl group having 7 to 40 carbon atoms, and M represents an
alkali metal or alkaline earth metal.)
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] FIG. 1 is a set of schematic illustrations showing examples
of lateral cross-sectional shapes for modified cross-section
polyester fibers which achieve the second object of the
invention.
[0046] FIG. 2 is a schematic illustration showing one example of a
lateral cross-sectional shape for modified cross-section polyester
fibers which achieves the second object of the invention, for
explanation of the dimensions.
[0047] FIG. 3 is a schematic illustration showing one example of a
lateral cross-sectional shape for modified cross-section polyester
fibers which achieves the third object of the invention.
[0048] FIG. 4 is a schematic illustration showing one example of
the discharge hole of a spinneret used for spinning of modified
cross-section polyester fibers which achieves the third object of
the invention.
[0049] FIG. 5 is a schematic illustration showing one example of a
lateral cross-sectional shape for modified cross-section polyester
fibers before alkali reduction treatment, which achieves the fourth
object of the invention.
[0050] FIG. 6 is a schematic illustration showing examples of
spinneret discharge holes used for spinning of modified
cross-section polyester fibers which achieve the fourth object of
the invention.
[0051] FIG. 7 is a schematic illustration showing a side view of
modified cross-section polyester fibers (after alkali reduction
treatment) which achieves the fourth object of the invention.
[0052] FIG. 8 is a schematic illustration showing one example of a
lateral cross-sectional shape for modified cross-section polyester
fibers which achieves the fifth object of the invention, for
explanation of the dimensions.
[0053] FIG. 9 is a schematic illustration showing one example of
the discharge hole of a spinneret used for spinning of modified
cross-section polyester fibers which achieves the fifth object of
the invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0054] It is an essential feature of the modified cross-section
polyester fibers of the invention that they are polyester fibers
comprising a polyester polymer as the main component and having an
modified cross-section, and that the polyester polymer is produced
by polycondensation of an aromatic dicarboxylate ester in the
presence of the specific catalyst described hereunder. This makes
it possible to obtain modified cross-section polyester fibers
having satisfactory color tone as well as no fluff and high
quality, despite being spun from a spinneret with a complex
discharge hole. In addition, since production can be stably
accomplished from the polymer even if the modified cross-section
polyester fibers have a high degree of irregularity, the fibers can
exhibit adequate functions by their irregularity (water absorption,
antifouling property, non-permeability) and hand (touch, color tone
change, luster, etc.). The "modified cross-section" means a
cross-sectional shape which is not a circular shape, such as an
elliptical, flat, triangular, square, cross-shaped, star-shaped,
C-shaped, H-shaped, I-shaped, L-shaped, S-shaped, T-shaped,
U-shaped, V-shaped, W-shaped, X-shaped, Y-shaped or Z-shaped
cross-section. The effect of the invention is more notably
exhibited with complex cross-sectional shapes and modified
cross-sections with strictly defined angles and dimensions of each
portion of the cross-section.
[0055] The polycondensation catalyst comprises at least one
selected from among (1) mixtures of the titanium compound component
(A) and phosphorus compound component (B) described below and (2)
reaction products of the titanium compound component (C) and
phosphorus compound component (D) described below.
[0056] The titanium compound (A) of the mixture (1) for the
polycondensation catalyst is comprised at least one compound
selected from the group consisting of:
[0057] (a) titanium alkoxides represented by the following general
formula (I): ##STR6## [wherein R.sup.1, R.sup.2, R.sup.3 and
R.sup.4 each independently represent one species selected from
among alkyl groups having 1 to 20 atoms, preferably 1 to 6 atoms,
and phenyl groups, m represents an integer of 1-4 and preferably
2-4, and when m is an integer of 2, 3 or 4, the two, three or four
R.sup.2 and R.sup.3 groups may be the same or different], and
[0058] (b) reaction products of titanium alkoxides of general
formula (I) above with aromatic polyvalent carboxylic acids
represented by the following general formula (II): ##STR7##
[wherein n represents an integer of 2-4 and preferably 3-4] or
their anhydrides.
[0059] The phosphorus compound (B) of the mixture (1) for the
polycondensation catalyst is comprised at least one compound
represented by the following general formula (III): ##STR8##
[wherein R.sup.5, R.sup.6 and R.sup.7 each independently represent
alkyl groups having 1 to 4 carbon atoms, and X represents at least
one species selected from among --CH.sub.2-- group and
--CH.sub.2(Y) group (where Y represents phenyl group)].
[0060] The reaction product (2) for a polycondensation catalyst is
the reaction product of a titanium compound component (C) and
phosphorus compound component (D).
[0061] The titanium compound component (C) is comprised at least
one compound selected from the group consisting of:
[0062] (c) titanium alkoxides represented by formula (I) above
and
[0063] (d) reaction products of titanium alkoxides of general
formula (I) above with aromatic polyvalent carboxylic acids
represented by general formula (II) above or their anhydrides.
[0064] The phosphorus compound component (D) is comprised at least
one phosphorus compound represented by the following general
formula (IV): ##STR9## [wherein R.sup.8 represents alkyl groups
having 1 to 20 carbon atoms or aryl groups having 6 to 20 carbon
atoms, and p represents an integer of 1 or 2].
[0065] When a mixture (1) of the titanium compound component (A)
and the phosphorus compound component (B) is used as the
polycondensation catalyst, the titanium alkoxide (a) represented by
general formula (I) or the reaction product (b) of the titanium
alkoxide (a) and the aromatic carboxylic acid represented by
general formula (II) or its anhydride, used as the titanium
compound component (A), have high solubility and compatibility for
polyester polymers, and therefore even if residue of the titanium
compound component (A) remains in the polyester polymer obtained by
polycondensation, there is no accumulation of foreign matter around
the spinneret during melt spinning, so that polyester fibers of
satisfactory quality can be produced with high spinning
efficiency.
[0066] As titanium alkoxides (a) represented by general formula (I)
to be used in the polycondensation catalyst titanium compound
component (A) or (C) according to the invention, there are
preferred tetraisopropoxytitanium, tetrapropoxytitanium,
tetra-n-butoxytitanium, tetraethoxytitanium, tetraphenoxytitanium,
octaalkyl trititanate and hexaalkyl dititanate.
[0067] The aromatic polyvalent carboxylic acid of general formula
(II) or its anhydride which is reacted with the titanium alkoxide
(a) or (c) is preferably selected from among phthalic acid,
trimellitic acid, hemimellitic acid, pyromellitic acid, and their
anhydrides. In particular, using trimellitic anhydride will yield a
reaction product exhibiting high affinity for the polyester
polymer, and is effective for preventing accumulation of foreign
matter.
[0068] When the titanium alkoxide (a) or (c) for the titanium
compound component (A) or (C) is reacted with the aromatic
polyvalent carboxylic acid of general formula (II) or its
anhydride, it is preferred, for example, to dissolve the aromatic
polyvalent carboxylic acid or its anhydride in a solvent, add the
titanium alkoxide (a) or (c) dropwise to the solution and heat the
mixture for at least 30 minutes at a temperature of 0-200.degree.
C. The solvent used in this case is preferably selected as desired
from among ethanol, ethylene glycol, trimethylene glycol,
tetramethylene glycol, benzene and xylene.
[0069] There is no particular restriction on the molar ratio for
reaction between the titanium alkoxide (a) or (c) with the aromatic
polyvalent carboxylic acid of general formula (II) or its
anhydride, but if the proportion of the titanium alkoxide is too
high, the color tone of the resulting polyester may be impaired or
the softening point may be lowered, whereas if the proportion of
the titanium alkoxide is too low, the polycondensation reaction may
be impeded. The molar ratio for the reaction between the titanium
alkoxide (a) or (c) with the aromatic polyvalent carboxylic acid of
general formula (II) or its anhydride is therefore preferably in
the range of (2:1) to (2:5).
[0070] The reaction product (b) or (d) obtained by the reaction may
be used directly, or it may be used after purification by
recrystallization with acetone, methyl alcohol and/or ethyl
acetate.
[0071] The phosphorus compound (phosphonate compound) of general
formula (III) to be used for a phosphorus compound component (B) of
the mixture (1) for the polycondensation catalyst according to the
invention is preferably selected from among dimethyl esters,
diethyl esters, dipropyl esters and dibutyl esters of phosphonic
acid derivatives such as carbomethoxymethane-phosphonic acid,
carboethoxymethanephosphonic acid, carbopropoxymethanephosphonic
acid, carbobutoxymethane-phosphonic acid,
carbomethoxyphenylmethanephosphonic acid,
carboethoxyphenylmethanephosphonic acid,
carbopropoxyphenyl-methanephosphonic acid,
carbobutoxyphenylmethanephosphonic acid, and the like.
[0072] When a phosphorus compound component (B) composed of a
phosphorus compound (phosphonate compound) of general formula (III)
is used for polycondensation reaction of the aromatic dicarboxylate
ester, the reaction with the titanium compound component (A)
proceeds more moderately as compared to phosphorus compounds
ordinarily used as reaction stabilizers, and therefore the
catalytically active life of the titanium compound component (A)
during the polycondensation reaction process is longer and as a
result, a smaller proportion of the titanium compound component (A)
may be used with respect to the amount of the aromatic
dicarboxylate ester in the polycondensation reaction system. Also,
even if a large amount of stabilizer is added to the
polycondensation reaction system containing a phosphorus compound
component (B) composed of a phosphorus compound of general formula
(III), there is no reduction in thermal stability of the obtained
polyester polymer and its color tone is also satisfactory.
[0073] When the mixture (1) is used as the polycondensation
catalyst according to the invention, the mixture (1) is used with a
mixing ratio such that the ratio (%) M.sub.Ti of the millimoles of
titanium element in the titanium compound component (A) with
respect to the number of moles of the aromatic dicarboxylate ester
and the ratio (%) M.sub.p of the millimoles of phosphorus element
in the phosphorus compound component (B) with respect to the number
of moles of the aromatic dicarboxylate ester satisfy the following
relational expressions (i) and (ii):
1.ltoreq.M.sub.p/M.sub.Ti.ltoreq.15 (i)
10.ltoreq.M.sub.p+M.sub.Ti.ltoreq.100 (ii).
[0074] The ratio M.sub.p/M.sub.Ti is between 1 and 15, and
preferably between 2 and 10. If the ratio M.sub.p/M.sub.Ti is less
than 1, the color tone of the obtained polyester polymer may be
yellowish, while if it is greater than 15, the polycondensation
reactivity of the polycondensation catalyst of such a composition
will be insufficient, making it difficult to obtain the intended
polyester polymer. The range for the ratio M.sub.p/M.sub.Ti
according to the invention is relatively narrow compared to that
for conventional Ti--P catalysts, but establishing such a range
produces an excellent effect which has not been obtained with
conventional Ti--P catalysts.
[0075] The value of the sum (M.sub.p+M.sub.Ti) is between 10 and
100, and preferably between 20 and 70. If the value of
(M.sub.p+M.sub.Ti) is less than 10, the fiber-forming property of
the obtain polyester polymer, the production efficiency in the melt
spinning process and the performance of the obtained fibers will be
inadequate. If the value of (M.sub.p+M.sub.Ti) is greater than 100,
a small but significant degree of foreign matter accumulation will
occur around the spinneret when the obtained polyester polymer is
used for melt spinning. The value of M.sub.Ti is generally
preferred to be 2-15 and more preferably 3-10.
[0076] When the reaction product (2) is used as a polycondensation
catalyst according to the invention, the phosphorus compound of
general formula (IV) used as the phosphorus compound (D) may be,
for example, a monoalkyl phosphate such as mono-n-butyl phosphate,
monohexyl phosphate, monododecyl phosphate, monolauryl phosphate or
monooleyl phosphate; a monoaryl phosphate such as monophenyl
phosphate, monobenzyl phosphate, mono(4-ethylphenyl) phosphate,
monobiphenyl phosphate, mononaphthyl phosphate or monoanthryl
phosphate; a dialkyl phosphate such as diethyl phosphate, dipropyl
phosphate, dibutyl phosphate, dilauryl phosphate or dioleyl
phosphate, or a diaryl phosphate such as diphenyl phosphate.
Preferred among these are monoalkyl phosphates or monoaryl
phosphates, wherein p in formula (IV) is 1.
[0077] The phosphorus compound component (D) used for the invention
may be a mixture of two or more phosphorus compounds of general
formula (IV), and as examples of preferred combinations there may
be mentioned mixtures of monoalkyl phosphates and dialkyl
phosphates or mixtures of monophenyl phosphates and diphenyl
phosphates. Particularly preferred are compositions wherein a
monoalkyl phosphate constitutes at least 50% and especially at
least 90% of the mixture based on the total weight of the
mixture.
[0078] The method of preparing the reaction product of the titanium
compound component (C) and phosphorus compound component (D) may
involve, for example, combining the components (C) and (D) and
heating them in glycol. Specifically, heating a glycol solution
containing the titanium compound component (C) and the phosphorus
compound component (D) will cause clouding of the glycol solution
with precipitation of the components (C) and (D) as reaction
products. The precipitate may be collected for use as a catalyst
for polyester polymer production.
[0079] The glycol used in this case is preferably the same glycol
component for the polyester to be produced using the obtained
catalyst. For example, ethylene glycol is preferred when the
polyester is polyethylene terephthalate, 1,3-propanediol is
preferred when it is polytrimethylene terephthalate and
tetramethylene glycol is preferred when it is polytetramethylene
terephthalate.
[0080] The polycondensation reaction product (2) according to the
invention may be produced by a method of simultaneously combining
the titanium compound component (C) and phosphorus compound (D) and
the glycol, and heating them. However, since heating causes the
titanium compound component (C) and phosphorus compound component
(D) to react and produce a precipitated reaction product which is
insoluble in glycol, it is preferred for the reaction up to
precipitation to proceed in a uniform manner. In order to
efficiently obtain the reaction precipitate, therefore, the
preferred production process is one in which separate glycol
solutions of the titanium compound component (C) and phosphorus
compound component (D) are prepared beforehand, and the solutions
are then combined and heated.
[0081] The temperature for the reaction between components (C) and
(D) is preferably between 50.degree. C. and 200.degree. C., and the
reaction time is preferably from 1 minute to 4 hours. If the
reaction temperature is too low, the reaction may proceed
insufficiently or an excessive reaction time may be required,
making it impossible to efficiently obtain a reaction precipitate
by uniform reaction.
[0082] The mixing proportion of the titanium compound component (C)
and phosphorus compound component (D) heated to reaction in glycol
is preferably in the range of 1.0 to 3.0 and more preferably 1.5 to
2.5, as the molar ratio of phosphorus atoms with respect to
titanium atoms. Within this range, the phosphorus compound
component (D) and titanium compound component (C) will react almost
completely, in order to avoid the presence of an incomplete
reaction product, and therefore the reaction product may be used
directly to yield a polyester polymer with a satisfactory color
tone. In addition, the virtual lack of excess unreacted phosphorus
compound (V) results in high productivity without impeding the
polyester polymerization reactivity.
[0083] The reaction product (2) for the polycondensation catalyst
used for the invention preferably comprises a compound represented
by the following general formula (VI): ##STR10## (wherein R.sup.10
and R.sup.11 each independently represent at least one species
selected from among C.sub.6-12 aryl groups derived from R.sup.1,
R.sup.2, R.sup.3 and R.sup.4 in general formula (I) representing
the titanium alkoxide for titanium compound component (C) and
R.sup.8 in general formula (IV) representing the phosphorus
compound for phosphorus compound component (D).
[0084] Since the reaction product of the titanium compound and the
phosphorus compound (III) or (IV) represented by formula (VI) has
high catalytic activity, polyester polymers obtained using it have
satisfactory color tone (low b value), and exhibit satisfactorily
practical polymer performance with a sufficiently low content of
acetaldehydes, residual metals and cyclic trimers for practical
use. The reaction product represented by formula (VI) is preferably
present at 50 wt % or greater and more preferably at 70 wt % or
greater.
[0085] If the aromatic dicarboxylate ester is subjected to
polycondensation in the presence of the reaction product (2), it
may be used as a polyester production catalyst directly, without
separating the glycol and the precipitated reaction product (2)
obtained in the aforementioned manner. Also, after the precipitate
has been separated from the glycol solution containing the
precipitated reaction product (2) by means such as centrifugal
precipitation or filtration, the precipitated reaction product (2)
may be recrystallized with, for example, acetone, methyl alcohol
and/or water for purification and the purified product used as the
catalyst. The structure of the catalyst may be confirmed by solid
NMR and XMA metal quantitative analysis.
[0086] The polyester polymer used for the invention is obtained by
polycondensation of an aromatic dicarboxylate ester in the presence
of a catalyst comprising the aforementioned mixture (1) of a
titanium compound component (A) and phosphorus compound
(phosphonate compound) (B) and/or the reaction product (2) of a
titanium compound component (C) and a phosphorus compound component
(D). According to the invention, the aromatic dicarboxylate ester
is preferably a diester comprising an aromatic dicarboxylic acid
component and an aliphatic glycol component.
[0087] The aromatic dicarboxylic acid is preferably composed mainly
of terephthalic acid. More specifically, terephthalic acid
preferably constitutes at least 70 mole percent based on the total
aromatic dicarboxylic acid component content. As examples of
preferred aromatic dicarboxylic acids other than terephthalic acid
there may be mentioned phthalic acid, isophthalic acid,
naphthalenedicarboxylic acid, diphenyldicarboxylic acid and
diphenoxyethanedicarboxylic acid.
[0088] The aliphatic glycol component is preferably an alkylene
glycol, of which there may be used, for example, ethylene glycol,
trimethylene glycol, propylene glycol, tetramethylene glycol,
neopentyl glycol, hexanemethylene glycol and dodecamethylene
glycol, with ethylene glycol being particularly preferred.
[0089] According to the invention, the polyester polymer is
preferably a polyester comprising as its main repeating unit
ethylene terephthalate composed of terephthalic acid and ethylene
glycol. "Main" means that the ethylene terephthalate repeating unit
constitutes at least 70 mole percent of the total repeating units
in the polyester.
[0090] The polyester polymer used for the invention may also be a
mixed polyester obtained by copolymerization of polyester
components as the acid component or diol component.
[0091] As mixed carboxylic acid components there may be used the
aforementioned aromatic dicarboxylic acids, of course, as well
difunctional carboxylic acid components including aliphatic
dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid
and decanedicarboxylic acid and alicyclic dicarboxylic acids such
as cyclohexanedicarboxylic acid, or their ester-forming
derivatives, as starting materials. As mixed diol components there
may be used the aforementioned aliphatic diols, of course, as well
as alicyclic glycols such as cyclohexanedimethanol and aromatic
diols such as bisphenol, hydroquinone and
2,2-bis(4-.beta.-hydroxyethoxyphenyl)propane, as starting
materials.
[0092] In addition, there may also be used mixed polyester polymers
obtained by copolymerization of polyfunctional compounds such as
trimesic acid, trimethylolethane, trimethylolpropane,
trimethylolmethane and pentaerythritol as mixed components.
[0093] Such polyester polymers and mixed polyester polymers may be
used alone or in combinations of two or more.
[0094] According to the invention, the polyester polymer used is
preferably the polycondensation product of an aromatic
dicarboxylate ester composed of an aromatic dicarboxylic acid and
aliphatic glycol, as described above. The aromatic dicarboxylate
ester may also be produced by diesterification reaction of an
aromatic dicarboxylic acid and an aliphatic glycol, or it may be
produced by transesterification of an aromatic dicarboxylic acid
dialkyl ester and an aliphatic glycol. However, methods involving
transesterification using dialkyl esters of aromatic dicarboxylic
acids as starting materials are more advantageous than methods of
diesterification using aromatic dicarboxylic acids as starting
materials, because they produce less debris of the phosphorus
compound added as a phosphorous stabilizer during the
polycondensation reaction.
[0095] Also, all or a portion of the titanium compound component
(A) or (C) is preferably added before initiation of the
transesterification reaction, for use as a double reaction
catalyst, i.e. a transesterification reaction catalyst and
polycondensation reaction catalyst. This will allow a reduction in
the titanium compound content of the final polyester. More
specifically, in the case of polyethylene terephthalate, for
example, transesterification reaction between an aromatic
dicarboxylic acid dialkyl ester (composed mainly of terephthalic
acid) and ethylene glycol is preferably carried out in the presence
of the titanium compound component (A) comprising (a) at least one
compound selected from the group consisting of titanium alkoxides
represented by general formula (I) above and (b) products of
reaction between titanium alkoxides of general formula (I) with
aromatic polyvalent carboxylic acids represented by general formula
(II) above or their anhydrides. A phosphorus compound (phosphonate
compound) represented by general formula (III) above, or the
reaction product of a titanium compound component (C) and the
aforementioned phosphorus compound component (D), is preferably
further added to the reaction mixture comprising the diester of the
aromatic dicarboxylic acid and ethylene glycol obtained by the
transesterification reaction, and polycondensation reaction is
conducted in their presence.
[0096] The transesterification reaction will normally be conducted
under ordinary pressure, but conducting it under a pressure of
0.05-0.20 MPa will further promote the reaction catalyzed by the
action of the titanium compound component (A) while also avoiding
bulk generation of diethylene glycol by-product, so that more
favorable thermal stability and other properties can be achieved.
The temperature is preferably 160-260.degree. C.
[0097] When the aromatic dicarboxylic acid used for the invention
is terephthalic acid, the starting materials used for the polyester
will be terephthalic acid and dimethyl terephthalate. In this case,
there may be used recovered dimethyl terephthalate obtained by
depolymerization of a polyalkylene terephthalate, or recovered
terephthalic acid obtained by hydrolysis thereof. The use of
reprocessed polyesters from salvaged PET bottles, fiber products,
polyester film products and the like is preferred from the
standpoint of effective utilization of resources.
[0098] The polycondensation reaction may be carried out in a single
tank or in a plurality of separate tanks. The obtained product is a
polyester according to the invention, and the polyester obtained by
the polycondensation process is usually extruded in a molten state
and cooled to form particles (chips).
[0099] The polyester used for the invention, which is obtained by
the polycondensation process described above, may be further
subjected to solid phase polycondensation if desired.
[0100] The solid phase polycondensation consists of one or more
steps and is carried out at a temperature of 190-230.degree. C.
under a pressure of 1 kPa to 200 kPa in an inert gas atmosphere
such as nitrogen, argon or carbon dioxide gas.
[0101] The particulate polyester obtained from the solid phase
polycondensation process is then subjected to water treatment
involving contact with water, steam, a steam-laden inert gas or
steam-laden air as necessary, for inactivation of the catalyst
remaining in the chips.
[0102] The polyester production process described above comprising
esterification and polycondensation steps may be carried out in a
batch, semi-continuous or continuous system.
[0103] The polyester polymer used for the invention is preferably
selected from among polyethylene terephthalate, polytrimethylene
terephthalate and polytetramethylene terephthalate.
[0104] The polyester used for the invention preferably has an L*
value of 77-85 and a b* value of 2-5 based on the L*a*b* color
system (JIS Z8729).
[0105] The intrinsic viscosity of the polyester used for the
invention obtained in the manner described above is preferably in
the range of 0.40-0.80, more preferably 0.45-0.75 and even more
preferably 0.50-0.70. The intrinsic viscosity is preferably not
less than 0.40 because the tenacity of the fibers may be
insufficient. On the other hand, an intrinsic viscosity of greater
than 0.80 is uneconomical because it requires excessive raising of
the intrinsic viscosity of the starting polymer.
[0106] The polyester used for the invention may, if necessary,
contain small amounts of additives such as antioxidants,
ultraviolet absorbers, flame retardants, fluorescent brighteners,
delustering agents, color correctors, antifoaming agents,
antistatic agents, antimicrobial agents, light stabilizers, thermal
stabilizers, light blockers or the like, and preferably there are
added titanium dioxide as a delustering agent and antioxidants as
stabilizers.
[0107] The titanium dioxide used preferably has a mean particle
size of 0.01-2 .mu.m, and is preferably included in the polyester
polymer at 0.01-10 wt %.
[0108] Incidentally, the catalyst-derived titanium content in the
polyester polymer does not include the titanium derived from any
titanium dioxide added as a delustering agent.
[0109] When the polyester polymer contains titanium dioxide as a
delustering agent, the titanium dioxide of the delustering agent
may be removed from the polyester polymer sample for measurement by
dissolving the polyester polymer in hexafluoroisopropanol,
supplying the solution to centrifugation treatment to separate and
precipitate the titanium dioxide particles from the solution,
separating and collecting the supernatant liquid by the gradient
method and evaporating off the solvent from the collected fraction
to prepare the testing sample.
[0110] As antioxidants there are preferably used hindered
phenol-based antioxidants. An antioxidant is preferably added at no
greater than 1 wt % and more preferably 0.005-0.5 wt %. Addition in
excess of 1 wt % will result in a saturated effect and may cause
scum production during melt spinning. Hindered phenol-based
antioxidants may also be used in combination with thioether-based
secondary antioxidants.
[0111] There are no particular restrictions on the method of adding
such antioxidants to the polyester, and they may be added at any
desired stage from initiation of the transesterification reaction
to completion of the polycondensation reaction.
[0112] The second object of the invention is to provide, in
addition to the first object, modified cross-section polyester
fibers which produce cloths having no sticky feel and excellent
softness, anti-penetration property, low air permeability, water
absorption and wear resistance, and this object is achieved by the
modified cross-section polyester fibers described below.
[0113] Specifically, these are modified cross-section polyester
fibers comprising as the principal component a polyester polymer
obtained by polycondensation in the presence of the aforementioned
specific catalyst, wherein the lateral cross-sections of the fibers
are flat-shaped, and the flat shape is a form with 3-6 round
cross-sectional shapes joined in the lengthwise direction.
[0114] Here, "joined" does not mean actually joined on the level of
melt spinning, but rather that the result is a "joined" shape.
Also, the "round cross-sectional shapes" are not necessarily
perfectly round but may also be elliptical.
[0115] The lateral cross-sectional shapes of the fibers will now be
explained with respect to FIG. 1. FIGS. 1(a) to (c) are schematic
illustrations of lateral cross-sectional shapes for the fibers,
with (a) showing 3, (b) showing 4 and (c) showing 5 joined round
cross-sectional shapes.
[0116] That is, the lateral cross-sectional shapes of the fibers
are forms with round cross-sectional shapes joined in the
lengthwise direction (long-axis direction), where hill/hill pairs
and valley/valley pairs are aligned symmetrically on either side of
the long axis, and the number of these round cross-sectional shapes
is preferably 3 to 6. When the number of round cross-sectional
shapes is 2, the softness approaches that of a cloth with round
cross-sectional fibers, but the anti-penetration property, low air
permeability and water absorption tend to be reduced. On the other
hand, when the number of round cross-sectional shapes is greater
than 7, the fibers are more susceptible to breakage and tend to
have lower wear resistance.
[0117] The modified cross-section polyester fibers preferably
comprise inorganic particles at 0.2-10 wt %, for an improved
anti-penetration property.
[0118] Referring next to FIG. 2, the flatness represented by A/B as
the ratio of the width A of the long axis of the lateral
cross-section of the modified cross-section polyester fibers to the
maximum width B of the short axis perpendicular to the long axis A
is preferably 3 to 6. If it is smaller than 3 the softness is
reduced, while if it is greater than 6, a sticky feel tends to be
produced.
[0119] From the standpoint of eliminating a sticky feel and
improving the water absorption of the modified cross-section
polyester fibers, the irregularity represented by B/C as the ratio
of the maximum width B of the short axis of the flat cross-section
to the minimum width C (minimum width at the joints of the round
cross-sectional shapes) is preferably such that 1<B/C<5.
Specifically, since water is diffused by capillary action in the
valleys of the flat cross-section fibers of the invention, an
excellent water absorption property is obtained compared to round
cross-section fibers, whereas an irregularity degree of only 1
produces simple flat fibers, resulting in a sticky feel and
eliminating the water absorption property. If B/C is greater than
5, it is possible to avoid a sticky feel while imparting a water
absorption property, but other disadvantages can occur, i.e., the
joints of the round cross-sectional shapes become too short and the
tenacity of the flat cross-section fibers is reduced tending to
result in yarn breakage, and therefore B/C is preferably such that
1<B/C<5 and more preferably 1.1.ltoreq.B/C.ltoreq.2.
[0120] There are no particular restrictions on the single fiber
size of the modified cross-section polyester fibers or on the
overall strand size of modified cross-section polyester fibers
composed of the single fibers, but for use in clothing, the single
fiber size is preferably 0.3-3.0 dtex and the overall strand size
of modified cross-section polyester fibers is preferably 30-200
dtex.
[0121] It is a third object of the invention to provide, in
addition to the first object, modified cross-section polyester
fibers with excellent water absorption and quick-drying properties.
This object is achieved by the following modified cross-section
polyester fibers.
[0122] Specifically, these are modified cross-section polyester
fibers comprising as the principal component a polyester polymer
obtained by polycondensation in the presence of the aforementioned
specific catalyst, wherein 3-8 fins protrude outward from the fiber
cross-section core in the lateral cross-section of each fiber, and
the protrusion coefficient as defined by formula (iii) below is
between 0.3 and 0.7. Protrusion
coefficient=(a.sub.1-b.sub.1)/a.sub.1 (iii) [Here, a.sub.1
represents the length from the center of an inscribed circle in the
inner wall of the fiber cross-section to the tip of the fin, and
b.sub.1 represents the radius of the inscribed circle in the inner
wall of the fiber cross-section.]
[0123] Polyester fibers having such lateral cross-sectional shapes
have performance of withstanding impact during draw-false twisting
steps and of exhibiting adequate water absorption and quick-drying
properties in cloths even after draw-false twisting steps.
[0124] Such polyester fibers also generate low yarn breakage
(processing breaks) and fluff during draw-false twisting steps,
even when the false twisting steps are carried out under ordinary
conditions. The obtained draw-false twisted fibers also have
moderate dispersion of the degrees of flatness of the lateral
cross-sections of the fibers in the fiber axis directions, to
create fiber lateral cross-sections which are not uniform in the
fiber axis directions, thus forming fiber aggregates with large
gaps between the fibers. Such large gaps between fibers bring about
effects of greater water absorption and quick-drying performance,
and of enhanced washing durability of the performance. Fiber
aggregates having degrees of flatness of the lateral cross-sections
of the fibers moderately dispersed in the fiber axis directions
also exhibit performance giving a natural dry feel to cloths.
[0125] Fins having a protrusion coefficient of less than 0.3 do not
form adequate capillary gaps in the lateral cross-sections of the
fibers after draw-false twisting, and therefore cannot exhibit
water absorption or quick-drying properties. Such short fins also
exhibit a low anchor effect when the cloth is subjected to water
absorption treatment, such that the washing durability of the
treatment agent tends to be lowered. The hand of the cloth also
becomes more flat and paper-like. On the other hand, fins having a
protrusion coefficient of greater than 0.7 undergo more
concentration of working tension on the fins during draw-false
twisting, and therefore partial collapse of the fiber
cross-sections occurs making it impossible to achieve adequate
capillary formation, and the water absorption performance is
therefore lower.
[0126] Even with fins having a protrusion coefficient of 0.3-0.7,
if the number of such fins is 1 or 2 in the fiber lateral
cross-section, a maximum of only one inwardly closed fiber lateral
cross-section portion will be formed, and therefore the capillary
phenomenon will not be as easily expressed and the absorption
performance will be lower. The hand of the cloth will also tend to
become more flat and paper-like. With more than 8 fins, on the
other hand, working tension tends to concentration on the fins
during draw-false twisting, resulting in partial collapse of the
fiber cross-sections and making it impossible to achieve adequate
capillary formation, thereby lowering the water absorption
performance.
[0127] The fiber crystallinity of the modified cross-section
polyester fibers is preferably no greater than 30%, and the boiling
water shrinkage ratio is preferably at least 15%. This limits
increase in the crystalline region of the fibers to prevent too
rigid a fiber structure and thus facilitate moderate dispersion of
the degrees of flatness of the lateral cross-sections of the fibers
in the fiber axis directions, for draw-false twisted fibers under
ordinary draw-false twisting conditions. The result is improved
water absorption and quick-drying performance and enhanced washing
durability of the performance, as well as a natural dry feel for
cloths. On the other hand, a stable fiber structure can be obtained
by limiting the boiling water shrinkage ratio to no greater than
70%.
[0128] Any publicly known melt spinning method may be employed to
produce the modified cross-section polyester fibers described
above. For example, there may be employed a method of drying the
polyester under ordinary conditions, melting it with a melt
extruding machine, such as a screw extruder, discharging the melt
from a spinneret (FIG. 4) having 3 to 8 and preferably 4 to 6
fin-forming discharge holes consisting of connected small circular
openings (5 in FIG. 4) and slit openings (4 in FIG. 4), situated at
spaced distances around a core-forming round discharge hole (3 in
FIG. 4), such as disclosed, for example, in Japanese Patent
Application No. 3076372, and then cooling, solidifying and winding
up according to methods known in the prior art. In order to obtain
fibers with the crystallinity and boiling water shrinkage ratio
specified above, the winding speed is preferably 2000-4000 m/min
and more preferably 2500-3500 m/min.
[0129] Here, the radius of the core-forming round discharge hole
(b.sub.2 in FIG. 4) and the lengths of the ends of the fin-forming
discharge holes from the center of the circular discharge hole
(a.sub.2 in FIG. 4) may be altered to freely set the protrusion
coefficient of the fiber cross-sections to within 0.3-0.7. The spin
block temperature and/or cooling air flow volume may also be varied
to achieve some degree of control over the protrusion coefficient
of the fiber cross-sections. The cooling air is preferably blown
from a cross-flow type spinning stack with a length of 50-100 cm
situated with its top 5-15 cm below the spinneret.
[0130] It is a fourth object of the invention to provide, in
addition to the first object, modified cross-section polyester
fibers which produce cloths that are bulky and have a soft hand.
This object is achieved by the following modified cross-section
polyester fibers.
[0131] Specifically, these are modified cross-section polyester
fibers comprising as the principal component a polyester polymer
obtained by polycondensation in the presence of the aforementioned
specific catalyst, wherein the fiber lateral cross-section
comprises a core and multiple fins protruding in a radial fashion
from the core along the lengthwise direction of the core, and the
polyester fibers satisfying all of the following relationships (iv)
to (vi) are subjected to alkali reduction treatment to separate at
least some of the fins from the cores.
1/20.ltoreq.S.sub.B/S.sub.A.ltoreq.1/3 (iv)
0.6.ltoreq.L.sub.B/D.sub.A.ltoreq.3.0 (v)
W.sub.B/D.sub.A.ltoreq.1/4 (vi) (Here, S.sub.A represents the
cross-sectional area of the core, D.sub.A represents the core
diameter if the cross-section is a circle or the circumscribed
circle diameter if it is not a circle, and S.sub.B, L.sub.B and
W.sub.B represent the cross-sectional area, maximum length and
maximum width of the fins, respectively.)
[0132] FIG. 5 shows S.sub.A, D.sub.A, S.sub.B, L.sub.B and W.sub.B
for an example of a fiber lateral cross-section.
[0133] If S.sub.B/S.sub.A< 1/20 or S.sub.B/S.sub.A>1/3, i.e.
if fins are present having a cross-sectional area of smaller than
1/20 or larger than 1/3 of the cross-sectional area of the core,
the fiber bulk will be reduced.
[0134] Also, if L.sub.B/D.sub.A<0.6, i.e. if fins are present
having a maximum length of less than 0.6 times the core diameter,
the fiber bulk will be reduced, while on the other hand, if
L.sub.B/D.sub.A>3.0, i.e. if fins are present having a maximum
length of greater than 3.0 times the core diameter, the fins will
tend to bend and produce a rough hand.
[0135] In addition, if W.sub.B/D.sub.A>1/4, i.e. if fins are
present having a maximum width of larger than 1/4 the core
diameter, decomposition of the fins by alkali reduction treatment
will be impeded.
[0136] A smaller maximum width of the fins will facilitate
separation of the fins by alkali reduction treatment, but if it is
too small the fins will tend to bend, and therefore the minimum
value for W.sub.B/D.sub.A is preferably about 1/8.
[0137] As a more detailed explanation of the dimensions of the core
and fins of the fibers, the denier of the fins is preferably no
greater than 0.9 dtex and more preferably no greater than 0.7 dtex.
If the denier of the fins is too great, it will not be possible to
obtain a fine touch by split fins, and an increased fin area will
result in an inferior drape property by splitting. The size of the
core is preferably from 1 dtex to 5 dtex. If the core size is
greater than 5 dtex, it will not be possible to obtain adequate
softness even if the fins and core are split, and the hand of
fabrics will tend to be harder. If the size is less than 1 dtex,
the mutual filling effect will be increased even if the multilobal
cross-sections have sharp shapes, and it will thus tend to be
difficult to effectively obtain large gaps.
[0138] In the polyester fibers before alkali reduction treatment, a
compound having a compatibility parameter .chi. represented by
relationship (vii) below of 0.1-2.0 is preferably present in the
polyester fibers at 0.5-5.0 wt % with respect to the total fiber
weight. This will aid separation of the fins and cores, to obtain
effects of increased bulk and enhanced hand.
.chi.=(V.sub.a/RT)(.delta.a-.delta.b).sup.2 (vii) (Here, V.sub.a
represents the molar volume (cm.sup.3/mol) of the polyester, R
represents the gas constant (J/molK), T represents the absolute
temperature (K) and .delta.a and .delta.b represent the solubility
parameters (J.sup.1/2/cm.sup.3/2) of the polyester and compound,
respectively.)
[0139] If .chi. is less than 0.1 the polyester and the compound
become compatibilized making it difficult to separate the fins by
alkali reduction, while if .chi. is greater than 2.0 the polyester
and the compound become completely phase separated and the polymer
becomes thickened, thereby tending to lower the spinning
properties.
[0140] If the content of the compound in the polyester is less than
0.5 wt % it becomes difficult to achieve an effect of increased
bulk, while if the content is greater than 5.0 wt % the compound
tends to aggregate, thus impeding the same effect.
[0141] As specific examples for the compound there may be mentioned
polymers such as polyethylene, polypropylene, polyisobutylene,
polystyrene, polytetrafluoroethylene, polychlorotetraethylene,
polychlorotrifluoroethylene, polyvinyl propionate,
polyheptafluorobutyl acrylate, polybutadiene, polyisoprene,
polychloroprene, polyethylene glycol, polytetramethylene glycol,
polytriethylene glycol, polymethyl acrylate, polypropyl acrylate,
polybutyl acrylate, polyisobutyl acrylate, polymethyl methacrylate,
polyethyl methacrylate, polybenzyl methacrylate, polyethoxyethyl
methacrylate, polyformaldehyde, polyethylene sulfide and
polystyrene sulfide, as well as silicones and modified forms
thereof. These compounds may also be used in combinations of two or
more.
[0142] If the mean molecular weight of the compound is too low,
thermal decomposition will occur during residence in the extruder
or spinning pack, while if it is too high the melt miscibility with
the polyester is reduced, and therefore the preferred range is
3000-25,000.
[0143] For addition and mixing of the compound with the polyester,
there may be employed any desired publicly known method such as,
for example, a method of melt kneading the polyester and the
compound and pelleting the melt, a method of injection blending of
the compound into the molten polyester during the melt spinning
step, or a method of blending with a static mixer.
[0144] The polyester fibers prior to alkali reduction treatment may
be obtained by the following method, for example.
[0145] That is, the polyester may be melted and discharged through
a core-forming discharge hole while the same polyester melt
discharged through multiple fin-forming slit-shaped discharge holes
arranged in a radial fashion at spaced distances around the
discharge hole is joined therewith while in a molten state, and
both cooled to solidity.
[0146] More specifically, the polyester is melted and discharged
through a nozzle such as shown in FIG. 6A, for example, having a
core-forming round discharge hole 5 and multiple (four in FIG. 6A)
fin-forming slit-shaped discharge holes arranged in a radial
fashion at spaced distances around the core-forming round discharge
hole 5, and then the discharged polyester from the discharge hole 5
and the discharged polyester from the discharge holes 6 are joined
while in a molten state and cooled to solidity.
[0147] The spun filament may also be drawn and heat treated, if
necessary.
[0148] If the number of fins is 1 or greater than 7, the gaps
between the filaments formed by alkali reduction treatment are
small and it thus becomes difficult to impart adequate bulk. The
preferred number of fin-forming slit-shaped discharge holes
arranged around a single core-forming discharge hole is 3 to 6, and
more preferably 4. The cross-sectional areas, maximum lengths and
maximum widths of the fins do not necessarily need to be the same,
and they may be different for different fins. The fins preferably
protrude radially outward in an isotropic fashion around the center
core, but this is not a restrictive condition.
[0149] According to the invention, there are no particular
restrictions on the dimensions of the core-forming round discharge
hole 5 and the fin-forming slit-shaped discharge holes 6, but in
order for the core cross-sectional area and diameter and the fin
cross-sectional area, maximum length and maximum width to be within
the ranges specified by the three relationships (iv), (v) and (vi)
above, preferably the following conditions (x)-(xii) are all
satisfied for D'.sub.A, L'.sub.B, W'.sub.B and L'.sub.AB, where
D'.sub.A is the diameter of the core-forming round discharge hole 5
(or if the cross-sectional shape of the discharge hole 5 is not a
circle, D'.sub.A is the circumscribed circle diameter of the
discharge hole 5), L'.sub.B and W'.sub.B are the maximum length and
maximum width of the fin-forming slit-shaped discharge holes 6,
respectively, and L'.sub.AB is the shortest space between the
discharge holes 5 and 6 on the discharge plane.
1.ltoreq.L'.sub.B/D'.sub.A.ltoreq.4 (x)
1/7.ltoreq.W'.sub.B/D'.sub.A.ltoreq.1/2 (xi) 0.01
mm.ltoreq.L'.sub.AB.ltoreq.0.2 mm (xii)
[0150] When D'.sub.A, L'.sub.B, W'.sub.B and L'.sub.AB are outside
of these specified ranges, the spinning property may be impaired
and wear of the spinneret may be hastened.
[0151] The fin-forming slit-shaped discharge holes do not
necessarily need to be uniform rectangles, and as shown in FIG. 6B,
they may have arc-like swelled sections and their widths may also
vary continuously.
[0152] On the other hand, if a filament having a core and fins is
obtained by discharge of the polyester from a single discharge hole
instead of from the two different types of discharge holes 5,6 (or
6'), the core and fins will be integrated with roughly equal
orientations of the core and fins, and therefore separation of the
fins by the subsequent alkali reduction treatment will tend to be
more difficult.
[0153] In the spinning described above, a greater draft is applied
to the polymer discharged from the fin-forming slit-shaped
discharge hole than to the polymer discharged from the core-forming
discharge hole, so that the fins have higher orientation than the
core. In the resulting filament, therefore, there is little
entangling of the molecules at the joints between the core and fins
and the interfacial binding force at the joints is consequently
low, such that alkali reduction treatment will preferentially
separate the fins from the core. In addition, the core and fins
undergo different shrinkages due to their differences in
orientation, making it possible to obtain filaments with the
desired bulk and soft hand.
[0154] According to the invention, the obtained filaments are
subjected to alkali reduction treatment to separate at least some
of the fins from the cores because this manner of separation is
effective for minimizing formation of free protruding fibroid ends
(fluff) by cleavage of the fins or cores. If the filaments are
separated by employing physical means involving a large energy
transfer, such as fluid nozzle treatment using a high pressure air
flow such as exists in the prior art, a high volume of free
protruding fibroid ends are formed while the fins are also split
into a fibrillar form, thereby producing a woven or knitted fabric
with an outer appearance similar to spun yarn and impairing the
symmetry of the woven or knitted fabric.
[0155] The alkali reduction treatment may be carried out on the
filaments, or their yarn or woven or knitted fabric. However, it is
preferably carried out on a woven or knitted fabric. The alkali
treatment conditions employed may be alkali treatment conditions
for ordinary polyester filaments. Specifically, an aqueous solution
of sodium hydroxide, potassium hydroxide, sodium carbonate,
potassium carbonate or the like may be used, with appropriate
adjustment of the concentration to 10-100 g/liter, the temperature
to 40-180.degree. C. and the treatment time to between 2 minutes
and 2 hours.
[0156] The separation rate S of the fins by alkali reduction
treatment is preferably at least 30%, and the separation rate S of
the fins of filaments positioned in a multifilament yarn surface
layer is preferably larger than the separation rate S of the fins
of filaments positioned in the multifilament yarn center. The
separation rate S of the fins is the value defined by the following
formula: S(%)=(number of separated fins/total number of
fins).times.100
[0157] The filaments positioned in a multifilament yarn surface
layer are defined as those among the total number of multilobal
filaments at a close distance from an imaginary circumscribed
circle of the multifilament yarn to a range of 30% in the
cross-sections of the multifilaments. Likewise, the filaments
positioned at the center of the multifilament yarn are those at a
close distance from the center of the imaginary circumscribed
circle.
[0158] Such alkali reduction produces single fibers wherein the
fins are separated from the cores, as shown in FIG. 7. FIG. 7 is a
partially magnified view of modified cross-section polyester fibers
from the side, wherein 4 is the single fiber, 1 is the core and 2,3
are fins protruding in a radial fashion from the core and mostly
separated from the core.
[0159] In the modified cross-section polyester fibers 4 shown in
FIG. 7, the fins 2,3 joined to the core 1 along the lengthwise
direction of the core 1 and protruding in a radial fashion from the
core 1 are separated from the core 1 by the alkali reduction
treatment, producing independent fibers.
[0160] It is preferred for the fins to be continuously separated
from the core 1 along the entire length of the single fiber, as the
fin 2 in FIG. 7, to allow the fins to behave as independent fibers.
However, it is not essential for all of the fins to be separated
along the entire length of the filament, and parts thereof may be
connected to the core, as shown by the fin 3.
[0161] When the fins are separated from the core 1, for example in
a woven or knitted fabric, adequate gaps are provided between
adjacent cores and the woven or knitted fabric therefore has
satisfactory bulk (the example fiber shown in FIG. 5 has four fins
for one core, but in FIG. 7 there are only two fins 2,3 for the
single core).
[0162] The modified cross-section polyester fibers are preferably
combined and entangled amongst themselves or with other fibers to
make combined filament yarn, prepared into a woven or knitted
fabric, and then subjected to alkali reduction treatment. The
filaments may be combined and entangled into combined filament yarn
by any publicly known method such as paralleling, doubling, air
entangling or the like.
[0163] It is a fifth object of the invention to provide, in
addition to the first object, modified cross-section polyester
fibers which produce a silky cloth having a rough squeaky feel, an
excellent bulging feel, flexibility and a lightweight feel, with no
dye spots. This object is achieved by the following modified
cross-section polyester fibers.
[0164] Specifically, these are modified cross-section polyester
fibers comprising as the principal component a polyester polymer
produced by polycondensation in the presence of the aforementioned
specific catalyst, wherein the lateral cross-sectional shape is a
shape comprising a triangular shaped section and a protrusion
extending from one vertex of the triangular shape, where both of
the following relationships (viii) and (ix) are satisfied, and
having a hollow portion in the triangular shaped section
constituting 3-15% thereof. 0.7.ltoreq.L1/L2.ltoreq.3.0 (viii)
3.0.ltoreq.h2/h1.ltoreq.10.0 (ix) (Here, L1 represents the distance
from the connection point between the triangular shaped section and
the protrusion to the end of the protrusion, L2 represents the
distance between the connection point between the triangular shaped
section and the protrusion and the side of the triangular shaped
section opposite the connection point, h1 represents the width of
the protrusion and h2 represents the length of the side of the
triangular shaped section opposite the connection point between the
triangular shaped section and the protrusion.) If the extending
position of the protrusion differs from the vertex of the
triangular shape, for example, when it extends from the center of a
side of the triangular shape, the spinning property will tend to be
reduced, while if the protrusion extends from multiple vertices,
not only will the spinning property be reduced but the obtained
cloth hand will tend to lose its silk-like quality. Also, if the
shape of the protrusion is not flat, for example, if it has a shape
with a round cross-section, the squeaky feel of the cloth will be
less pronounced. Here, a flat shape is not necessarily uniformly
flat across the entire thickness, and portions thereof may be
thicker than others. In other words, the ratio (L1/h1) of the
protrusion length (L1) and width (h1) described below may be 2 or
greater and especially 5 or greater. If the ratio is less than 2
the shape cannot be referred to as "flat", and the obtained cloth
will lack a squeaky feel and flexibility.
[0165] The direction of extension of the protrusion from the
triangular shaped section is preferably at an angle within the area
enclosed by extrapolated lines from the two sides of the triangular
shape on either side of the vertex, and it is most preferably in
the direction of the bisector of the vertex.
[0166] The present invention will now be explained in greater
detail with reference to the accompanying drawings. FIG. 8 is a
schematic illustration showing the lateral cross-sectional shape of
modified cross-section polyester fibers. In FIG. 8, the connection
point between the triangular shaped section and flat protrusion is
the center point O between the two points where the outer perimeter
of the triangular shaped section (A) crosses the outer perimeter of
the flat protrusion (shown as a small white circle in the drawing
for convenience). The protrusion length L1 is the distance from the
connection point to the end of the protrusion, and L2 is the
distance between the connection point and the side of the
triangular shaped section (A). When the opposite side bulges
outward or recesses inward, L2 is the distance to a line parallel
to the line connecting the two vertices of the triangular shape
other than the connection point and tangential to the opposite
site.
[0167] The width h1 of the protrusion (B) is the maximum width of
the flat protrusion in the direction perpendicular to the direction
of extension of the protrusion (B), while the length h2 of the
opposite side is the space between two lines perpendicular to the
opposite side and touching the triangular shaped section (A).
[0168] Relational expression (viii) above defines the relationship
between the size of the triangular shaped section (A) and the
length of the flat protrusion (B), and since it is important for
achieving an overall squeaky feel, flexibility and bulging feel for
obtained cloths, L1/L2 is most preferably in the range of 1.5-2.5.
If the value is less than 0.7, it will be difficult to achieve an
overall squeaky feel and flexibility, while if it exceeds 3.0 it
will become difficult to accomplish stable yarn making and the
obtained cloth will lack a bulging feel.
[0169] Relational expression (ix) defines the relationship between
the size of the triangular shaped section (A) and the width of the
flat protrusion (B), and since it is important for achieving a
bulging feel for obtained cloths, h2/h1 is most preferably in the
range of 4.0-7.0. If the value is less than 3.0, the obtained cloth
will have an insufficient bulging feel, while if it exceeds 10.0
the discharge stability during spinning will be lower, making it
difficult to achieve stable yarn making.
[0170] A hollow portion with a hollow ratio of at least 3% must be
present in the triangular shaped section (A) in order to impart a
lightweight feel and bulging feel to cloths. However, if the hollow
ratio is too large the stable yarn making property is reduced, and
therefore the hollow ratio with respect to the triangular shaped
section (A) is limited to no greater than 15%. The hollow ratio is
more preferably in the range of 3-10%.
[0171] According to the invention, an organic sulfonic acid metal
salt represented by general formula (V) below is preferably present
in the polyester at 0.5-2.5 wt % with respect to the weight of the
polyester, so that the alkali reduction treatment can form fine
pores aligned in the direction of the fiber axes on the surfaces of
the modified cross-section fibers, and yield a cloth with an
enhanced dry feel and squeaky feel, and a quality very similar to
tussore silk.
[Chemical Formula 9] R.sup.9SO.sub.3M (V) (where R.sup.9 represents
alkyl group having 3 to 30 carbon atoms or aryl or alkylaryl group
having 7 to 40 carbon atoms, and M represents an alkali metal or
alkaline earth metal.)
[0172] When R.sup.9 in this formula is an alkyl or alkylaryl group,
the alkyl group may be a linear or branched side group. From the
viewpoint of compatibility with polyesters, R is most preferably an
alkyl group, for an alkylsulfonic acid metal salt. M is preferably
an alkali metal such as sodium, potassium or lithium, or an
alkaline earth metal such as calcium or magnesium, among which
sodium and potassium are preferred. As such organic sulfonic acid
metal salts there may be mentioned specifically sodium
stearylsulfonate, sodium octylsulfonate and sodium
laurylsulfonate.
[0173] The modified cross-section polyester fibers may be produced,
for example, by the following method.
[0174] FIG. 9 is a schematic illustration showing one example of
the shape of the discharge hole of a spinneret used for production
of the modified cross-section polyester fibers described above.
[0175] Specifically, the polyester is melt discharged at
280-300.degree. C. from a spinneret having the discharge hole shape
described above, a lubricant is applied to the cooled and
solidified spun filaments and interlacing is performed with an
interlacing apparatus if necessary, after which the undrawn yarn is
wound up onto a winder through a pair of take-up rollers set to
room temperature. The obtained undrawn yarn is then passed through
a pre-heating roller heated to 80-100.degree. C. and a non-contact
heater set to 170-240.degree. C. at a drawing speed of 600-1400
m/min, for drawing to a draw ratio of 1.5-3.0, and then further
interlaced if necessary.
[0176] The melt spinning temperature is preferably in the range of
275-300.degree. C. from the standpoint of spinning stability. The
spinning take-up speed and draw ration are appropriately set for a
polyester conjugated fiber tenacity in the range of 2.0-5.0 cN/dtex
and an elongation in the range of 30-50%.
[0177] The modified cross-section polyester fibers preferably have
a single fiber size of 1.5-5.0 dtex and an overall strand size of
50-170 dtex, and the boiling water shrinkage ratio is appropriately
in the range of 5.0-12.0%.
[0178] For production of a cloth using the modified cross-section
polyester fibers described above, appropriate twisting may be
carried out as necessary, and knitting or weaving performed to the
desired framework. The obtained cloth may if necessary be subjected
to alkali reduction treatment to provide an excellent squeaky feel,
bulging, flexibility and lightweightness which have not been
obtainable with woven or knitted fabrics of the prior art.
[0179] Since the intended object is a lightweight and squeaky feel,
weaving and knitting of complex frameworks are not preferred, but
instead, weaving and knitting of a plain weave or variations
thereof, a simple twill weave or variations thereof, a satin weave
or the like is preferred. In addition, the proportion of the
modified cross-section polyester fibers of the invention in the
cloth does not necessarily have to be 100%, but it is preferably a
large proportion in order to achieve an excellent squeaky feel,
bulging, flexibility and lightweightness.
EXAMPLES
[0180] The present invention will now be explained in detail
through the following examples, which are in no way limitative on
the invention. The parameters for the examples were measured by the
following methods.
[0181] (1) Intrinsic Viscosity
[0182] This was measured at 35.degree. C. using orthochlorophenol
as the solvent.
[0183] (2) Softness
[0184] An organoleptic evaluation was conducted by touch, with
judgment as 3: soft and very satisfactory, 2: satisfactory or 1:
rough/hard and unsatisfactory.
[0185] (3) Anti-Penetration Property
[0186] The L value was measured, and .DELTA.L was calculated as the
L value when using a white sheet minus the L value when using a
black sheet. A lower value was judged as an excellent
anti-penetration property.
[0187] (4) Air Permeability
[0188] This was measured according to Air Permeability Method A of
JIS L-1096-79-6.27, using a Frazil-type air permeability
tester.
[0189] (5) Water Absorption
[0190] This was measured by the "Byreck method" of JIS1096.
[0191] (6) Wear Resistance
[0192] After rubbing 3000 times with a Martindale Abrasion Tester,
cloths exhibiting no wear were judged as good, and those exhibiting
wear were judged as poor.
[0193] (7) Titanium Element Content, Phosphorus Element Content
[0194] A sample of the particulate polyester was heated to a melt
on an aluminum plate and then supplied to a compression press and
formed into a level molded test article, and the sample was
supplied to a Model 3270E fluorescent X-ray analyzer by Rigaku
Corp. for measurement of the titanium element content and
phosphorus element content.
[0195] (8) (L*-b*) Value
[0196] The polyester fiber was knitted to a 30 cm long tube knit
with a 12-gauge circular knitting machine, after which a Macbeth
COLOR EYE color measurement device was used for measurement of the
L* value and b* value, and the difference (L*-b*) was
determined.
[0197] (9) Fluff Count (/10.sup.6 m)
[0198] Upon placing 250 package-wound (or pirn-wound) polyester
fibers through a warping machine equipped with a fluff detector,
the yarns were warped and drawn for 42 hours at a speed of 400
m/min. The warping machine was periodically shut down and the
presence of fluff visually confirmed, and the total confirmed fluff
count was calculated per 10.sup.6 m of the strand length and
recorded as the fluff count.
Example 1
Preparation of Titanium Compound:
[0199] A 2 L three-necked flask equipped with a function allowing
mixing and stirring of the contents was prepared, 919 g of ethylene
glycol and 10 g of acetic acid were placed therein, and after
stirring and mixing, 71 g of titanium tetrabutoxide was slowly
added to obtain a (transparent) solution of a titanium compound in
ethylene glycol. This solution will hereinafter be abbreviated as
"TB solution". The titanium atom concentration of the solution was
1.02%.
Preparation of Phosphorus Compound:
[0200] A 2 L three-necked flask equipped with a function allowing
heating, mixing and stirring of the contents was prepared, and 656
g of ethylene glycol was placed therein and heated to 100.degree.
C. while stirring. Upon reaching 100.degree. C., 34.5 g of
monolauryl phosphate was added, and the mixture was heated, mixed
and stirred to dissolution to obtain a transparent solution. This
solution will hereinafter be abbreviated as "P1 solution".
Preparation of Catalyst:
[0201] Next, 310 g of the prepared TB solution was slowly added to
the P1 solution (approximately 690 g) under heating control at
100.degree. C. and stirring, and upon addition of the entire
amount, stirring was continued for 1 hour at a temperature of
100.degree. C. to complete reaction of the titanium compound and
phosphorus compound. The mixing ratio of the TB solution and P1
solution was 2.0 as the molar ratio of phosphorus atoms with
respect to titanium atoms. The product obtained by the reaction was
insoluble in ethylene glycol and was therefore present as a turbid,
fine precipitate. This solution will hereinafter be abbreviated as
"TP1-2.0 catalyst".
[0202] In order to analyze the obtained reaction precipitate, a
portion of the reaction solution was filtered with a 5.mu. pore
filter to obtain the precipitated reaction product as a solid, and
it was then washed with water and dried. The elemental
concentration of the obtained precipitated reaction product was
analyzed by XMA, yielding results of 12.0% titanium, 16.4%
phosphorus and a phosphorus atom molar ratio of 2.1 with respect to
titanium atoms. Solid NMR analysis yielded the following results.
C-13 CP/MAS (75.5 Hz frequency) measurement revealed disappearance
the butoxide-derived chemical shift peaks at 14 ppm, 20 ppm and 36
ppm for titanium tetrabutoxide, while P-31 DD/MAS (121.5 Hz
frequency) measurement confirmed a new chemical shift peak at 22
ppm not found in conventional monolauryl phosphate. These data
clearly indicated that the precipitate obtained under these
conditions was a new compound resulting from reaction of the
titanium compound and phosphorus compound.
[0203] Separately, a slurry prepared by mixing 179 parts by mass of
high purity terephthalic acid and 95 parts by mass of ethylene
glycol was supplied at a constant rate to a reactor already holding
225 parts by mass of an oligomer while stirring in a nitrogen
atmosphere under conditions kept at 255.degree. C., ordinary
pressure, and esterification reaction was carried out for 4 hours
to completion while removing out of the system the water and
ethylene glycol generated by the reaction. The esterification rate
was >98% and the polymerization degree of the produced oligomer
was about 5-7.
[0204] After transferring 225 parts by mass of the oligomer
obtained by the esterification reaction to a polycondensation
reactor, 3.34 parts by mass of the "TP1-2.0 catalyst" produced
earlier was charged in as the polycondensation catalyst. The
reaction temperature in the system was raised from 255.degree. C.
to 280.degree. C. and the reaction pressure lowered from
atmospheric pressure to 60 Pa in stages, for polycondensation
reaction while removing out of the system the water and ethylene
glycol generated by the reaction.
[0205] The extent of the polycondensation reaction was confirmed
while monitoring the load on the stirring blade in the system, and
the reaction was suspended when the desired degree of
polymerization was reached. During the reaction, titanium dioxide
was added as a delustering agent at 2.5 wt % based on the total
weight of the polyester. The reaction product in the system was
then continuously extruded into a strand from the discharge port
and then cooled and cut to obtain granular pellets of approximately
3 mm. The intrinsic viscosity of the obtained polyethylene
terephthalate was 0.62.
[0206] The polyethylene terephthalate pellets were spun from a
spinneret having 36 discharge holes each producing the single
filament cross-sectional shape shown in FIG. 1 at a spinning
temperature of 290.degree. C., and after application of a lubricant
and take-up at a speed of 3000 m/min, drawing was performed,
without winding up, at a pre-heating temperature of 85.degree. C.,
a heat setting temperature of 120.degree. C. and a draw ratio of
1.67, and the filaments were wound up at a speed of 5000 m/min to
obtain multifilaments comprising flat cross-sectional filaments
according to the invention, with a single filament size of 2.4 dtex
and an overall strand size of 86 dtex. The obtained multifilaments
were woven, without twisting of the warp or weft, into a plain
weave with a weaving density of 110 strands/2.54 cm and then dyed
by an established method, and the obtained cloth was evaluated by
the methods described above. The results are shown in Table 1.
Examples 2-3, Comparative Example 1
[0207] The same procedure was carried out as in Example 1, except
that the spinneret was replaced for discharge holes to produce the
shapes shown in FIGS. 1(b) and (c) and a round single filament
cross-sectional shape. The results are shown in Table 1.
Comparative Example 2
[0208] The same procedure was carried out as in Example 1, except
that the polycondensation catalyst was changed to a 1.3% solution
of antimony trioxide in ethylene glycol, the charged amount was
4.83 parts by mass, and there was further charged 0.121 part by
mass of a 25% solution of trimethyl phosphate in ethylene glycol as
a stabilizer. The results are shown in Table 1.
Comparative Example 3
[0209] The same procedure was carried out as in Example 1, except
that the TB solution prepared in Example 1 alone was used as the
polycondensation catalyst, and the charged amount was 1.03 parts by
mass. The results are shown in Table 1. TABLE-US-00001 TABLE 1
Comp. Comp. Comp. Example 1 Example 2 Example 3 Ex. 1 Ex. 2 Ex. 3
Cross-sectional shape (a) (b) (c) round (b) (b) Flatness 3 3.7 4.5
-- 3.7 3.7 Irregularity 2 2 2 -- 2 2 Softness 2 3 3 1 2 2 Sticky
feel none none none none none none Anti-penetration (.DELTA.L) 13.5
12.0 11.0 15.0 12.0 11.0 Air permeability 2.0 1.2 1.1 6.8 1.2 1.5
Water absorption 50 55 50 20 55 50 Wear resistance good good good
good good poor L* - b* 76 77 73 70 59 50 Fluff (/10.sup.6 m) 0.04
0.05 0.05 0.05 2.70 0.80
Example 4
[0210] After charging 0.009 part by mass of tetra-n-butyl titanate
(TBT) into a mixture of 100 parts by mass of dimethyl terephthalate
and 70 parts by mass of ethylene glycol in a pressure
reaction-capable stainless steel reactor, pressurization was
conducted at 0.07 MPa for transesterification reaction while
increasing the temperature from 140.degree. C. to 240.degree. C.,
and then 0.035 part by mass of triethyl phosphonoacetate (TEPA) was
added to terminate the transesterification reaction.
[0211] The reaction product was then transferred to a
polymerization reactor, the temperature was raised to 290.degree.
C., and polycondensation reaction was conducted in a high vacuum of
no greater than 26.67 Pa to obtain polyethylene terephthalate.
During the reaction, titanium dioxide was added as a delustering
agent at 2.5 wt % based on the total weight of the polyester. The
intrinsic viscosity of the polyethylene terephthalate was 0.62 and
the diethylene glycol content was 1.5%. The obtained polyethylene
terephthalate was also pelleted by an ordinary method.
[0212] The polyethylene terephthalate pellets were spun from a
spinneret having 36 discharge holes each producing the single
filament cross-sectional shape shown in FIG. 1 at a spinning
temperature of 290.degree. C., and after application of a lubricant
and take-up at a speed of 3000 m/min, drawing was performed,
without winding up, at a pre-heating temperature of 85.degree. C.,
a heat setting temperature of 120.degree. C. and a draw ratio of
1.67, and the filaments were wound up at a speed of 5000 m/min to
obtain multifilaments comprising flat cross-sectional filaments
according to the invention, with a single filament size of 2.4 dtex
and an overall strand size of 86 dtex. The obtained multifilaments
were woven, without twisting of the warp or weft, into a plain
weave with a weaving density of 110 strands/2.54 cm and then dyed
by an established method, and the obtained cloth was evaluated by
the methods described above. The results are shown in Table 2.
Examples 5-6, Comparative Example 4
[0213] The same procedure was carried out as in Example 4, except
that the spinneret was replaced for discharge holes to produce the
shapes shown in FIGS. 1(b) and (c) and a round monofilament
cross-sectional shape. The results are shown in Table 2.
Comparative Example 5
[0214] After charging 0.064 part by mass of calcium acetate
monohydrate into a mixture of 100 parts by mass of dimethyl
terephthalate and 70 parts by mass of ethylene glycol in a pressure
reaction-capable stainless steel reactor, pressurization was
conducted at 0.07 MPa for transesterification reaction while
increasing the temperature from 140.degree. C. to 240.degree. C.,
and then 0.044 part by mass of a 56 wt % aqueous phosphoric acid
solution was added to terminate the transesterification
reaction.
[0215] The reaction product was then transferred to a
polymerization reactor, diantimony trioxide was added in the amount
shown in the table, the temperature was raised to 290.degree. C.,
and polycondensation reaction was conducted in a high vacuum of no
greater than 26.67 Pa to obtain polyethylene terephthalate.
Titanium dioxide was added during the reaction in the same manner
as Example 4. The polyethylene terephthalate was also pelleted by
an ordinary method.
[0216] The same procedure was carried out as in Example 4 except
for using these polyethylene terephthalate pellets. The results are
shown in Table 2. TABLE-US-00002 TABLE 2 Comp. Comp. Example 4
Example 5 Example 6 Ex. 4 Ex. 5 Ti Type TBT TBT TBT TBT -- compound
Content (mmol %) 5 5 5 5 -- P Type TEPA TEPA TEPA TEPA -- compound
Content (mmol %) 30 30 30 30 -- Sb Type -- -- -- -- Sb.sub.2O.sub.3
compound Content (mmol %) -- -- -- -- 31 P/Ti 6 6 6 6 -- P + Ti 35
35 35 35 -- Cross-sectional shape (a) (b) (c) round (b) Flatness 3
3.7 4.5 -- 3.7 Irregularity 2 2 2 -- 2 Softness 2 3 3 1 2 Sticky
feel None none none none none Anti-penetration (.DELTA.L) 13.0 12.3
11.2 16.5 12.0 Air permeability 2.1 1.4 1.2 7.0 1.2 Water
absorption 52 57 52 16 55 Wear resistance Good good good good good
L* - b* 78 78 74 71 58 Fluff (/10.sup.6 m) 0.03 0.04 0.02 0.04
3.10
[0217] The present invention will now be further explained by
Examples 7-12 and Comparative Examples 6-7. The parameters for
these examples and comparative examples were measured by the
following methods.
[0218] (1) Crystallinity
[0219] This was determined by wide-angle X-ray diffraction. An
X-ray emitter (Rotorflex RU-200) by Rigaku Corp. was used for
measurement of the scattering intensity of Cu--K.alpha. rays
monochromatized with a nickel filter, and the crystallinity was
calculated by the following formula. Crystallinity=Scattering
intensity of crystalline portion/total scattering
intensity.times.100(%)
[0220] (2) Boiling Water Shrinkage Ratio
[0221] A skein with 20 turns was prepared using a sizing reel with
a frame perimeter of 1.125 m, and after applying a load of 0.022
cN/dtex, the skein was hung on a scale board and the initial skein
length L.sub.0 was measured. Next, the skein was treated for 30
minutes in a hot water bath at 65.degree. C. and then cooled and
again hung on a scale board, upon which the length L after
shrinkage was measured, and the boiling water shrinkage ratio was
calculated by the following formula. Boiling water shrinkage
ratio=(L.sub.0-L)/L.sub.0.times.100(%)
[0222] (3) Protrusion Coefficient
[0223] A cross-sectional micrograph was taken of the polyester
multifilament, the length (a.sub.1) from the center of an inscribed
circle in the inner wall of a single fiber cross-section to the tip
of the fin and the radius (b.sub.1) of the inscribed circle in the
inner wall of the fiber cross-section were measured, and the
protrusion coefficient was calculated by the following formula.
Protrusion coefficient=(a.sub.1-b.sub.1)/a.sub.1
[0224] (4) Titanium Element Content, Phosphorus Element Content
[0225] A sample of the particulate polyester was heated to a melt
on an aluminum plate and then supplied to a compression press and
formed into a level molded test article, and the sample was
supplied to a Model 3270E fluorescent X-ray analyzer by Rigaku
Corp. for measurement of the titanium element content and
phosphorus element content.
[0226] (5) Height of Spinneret Accumulation
[0227] After melt spinning with the method and conditions described
in each example, a release agent was blown onto the spinneret
surface, the spinneret was detached while avoiding adhesion of the
discharge polymer, and the height of spinneret accumulation which
had adhered and accumulated around the discharge hole was measured
using a microscope. The heights of spinneret accumulation of all of
the discharge holes were measured, and their average value was
recorded.
[0228] (6) Spinning Yarn Breakage (%)
[0229] The number of spinning yarn breaks during operation of the
spinning machine, excluding yarn breaks due to artificial or
mechanical factors, was recorded and the spinning yarn breakage was
calculated by the following formula. Spinning yarn breakage
(%)=[number of yarn breaks/(operating winder number.times.doffing
number)].times.100 Here, the doffing number is the number of times
the undrawn yarn package was wound up to a prescribed weight (10
kg).
[0230] (7) Working Yarn Breakage
[0231] A 10 kg wound polyester multifilament package was draw-false
twisted using an SDS-8 draw-false twisting machine by Scragg Co. to
prepare two 5 kg wound polyester false twisted yarn packages, the
number of yarn breaks during the operation was recorded, and the
working yarn breakage was calculated by the following formula.
Working yarn breakage=Number of yarn breaks/(number of operating
spindles.times.2).times.100
[0232] (8) Working Fluff
[0233] A DT-104 Fluff Counter by Toray Co., Ltd. was used to
determine the count of fluffs generated in the false twisted yarn
upon 20 minutes of continuous measurement at a speed of 50
m/min.
[0234] (9) Fabric Hand
[0235] Draw-false twist yarn was twisted at 600 turns/m and used as
warp and weft yarn to prepare a twill weave fabric. The fabric was
then subjected to scouring and relaxation treatment at 100.degree.
C., presetting dry heat treatment at 180.degree. C. for 45 seconds,
15% alkali reduction treatment and dyeing at 130.degree. C. for 30
minutes and naturally dried, after which final setting was
performed at 170.degree. C. for 45 seconds to prepare a woven
fabric. The fabric was judged for feel by an examiner and graded on
the following scale.
[0236] Level 1: Natural, dry feel
[0237] Level 2: Dry feel somewhat lacking
[0238] Level 3: Flat, paper-like feel
[0239] (10) Water Absorption/Quick-Drying Property (Wicking
Value)
[0240] The index used for the water absorption and quick-drying
performance was the number of seconds until dropped water droplets
no longer were reflected from the surface of a test fabric made of
polyester false twisted yarn (wicking number), based on 5.1.1 Speed
of Water Absorption (dropping method) in the water absorption test
method for fiber products according to JIS L1907. L.sub.10
represents the wicking value (sec) after washing 10 times by the
method of JIS L0844-A-2.
[0241] (11) (L*-b*) Value
[0242] The polyester fiber was knitted to a 30 cm long tube knit
with a 12-gauge circular knitting machine, after which a CR-200
Hunter-type differential calorimeter by Minolta was used for
measurement of the L* value and b* value, and the difference
(L*-b*) was determined.
Examples 7-9
[0243] Preparation of a titanium compound, phosphorus compound and
catalyst and production of an oligomer were carried out in the same
manner as Example 1.
[0244] After transferring 225 parts by mass of the obtained
oligomer to a polycondensation reactor, 3.34 parts by mass of the
"TP1-2.0 catalyst" produced earlier was charged in as the
polycondensation catalyst. The reaction temperature in the system
was then raised from 255.degree. C. to 280.degree. C. and the
reaction pressure was lowered from atmospheric pressure to 60 Pa in
stages, for polycondensation reaction while removing out of the
system the water and ethylene glycol generated by the reaction.
[0245] The extent of the polycondensation reaction was confirmed
while monitoring the load on the stirring blade in the system, and
the reaction was suspended when the desired degree of
polymerization was reached. The reaction product in the system was
then continuously extruded into a strand from the discharge port
and then cooled and cut to obtain granular pellets of approximately
3 mm. The intrinsic viscosity of the obtained polyethylene
terephthalate was 0.630.
[0246] Separately, a spinneret was prepared beforehand based on a
type of discharge hole with the discharge hole shape shown in FIG.
4, having 24 discharge hole groups each consisting of a
core-forming round discharge hole (b.sub.2 in FIG. 4) with a radius
of 0.15 mm and fin-forming discharge holes with a slit width of
0.10 mm and a length of 0.88 mm from the center of the round
discharge hole to the tip (a.sub.2 in FIG. 4) in the number shown
in Table 1, and it was incorporated into a spin pack and packed
into a spin block. The aforementioned polyethylene terephthalate
pellets were dried at 150.degree. C. for 5 hours and then melted
with a melt spinning apparatus equipped with a screw-type extruder,
introduced into the spin block at 295.degree. C., and extruded from
the spinneret at a discharge rate of 40 g/min. Next, cooling air at
25.degree. C. was blown into the polymer flow at a proportion of 5
Nm.sup.3/min from a cross-flow type spinning stack with a length of
60 cm situated with its top 10 cm below the spinneret discharge
plane, for cooling to solidification, after which a spinning
lubricant was applied and the filament was wound up at a speed of
3000 m/min to obtain polyethylene terephthalate filaments each
having the crystallinity, boiling water shrinkage ratio, number of
fins and protrusion coefficient shown in Table 3. This melt
spinning procedure was carried out continuously for 7 days.
[0247] The obtained polyethylene terephthalate filaments were
supplied to an SDS-8 draw-false twisting machine by Scragg Co.
(triple-axle disc false twisting unit, 216 spindles), for
draw-false twisting at a draw ratio of 1.65, a heater temperature
of 175.degree. C., a twist number of 3300/m and a draw-false
twisting speed of 600 m/min, to obtain polyethylene terephthalate
draw-false twisted yarn with a size of 84 dtex. The wicking values
(L.sub.0 and L.sub.10), fabric hands, working yarn breakages and
working fluff counts for Examples 1-3 and Comparative Example 1 are
summarized in Table 3.
Comparative Example 6
[0248] The same procedure was carried out as in Example 8, except
that the polycondensation catalyst was changed to a 1.3% solution
of antimony trioxide in ethylene glycol, the charged amount was
4.83 parts by mass, and there was further charged 0.121 part by
mass of a 25% solution of trimethyl phosphate in ethylene glycol as
a stabilizer. The results are shown in Table 3. TABLE-US-00003
TABLE 3 Example 7 Example 8 Example 9 Comp. Ex. 6 Polymerization
catalyst Reaction Reaction Reaction Sb.sub.2O.sub.3 product of
product of product of titanium titanium titanium tetrabutoxide
tetrabutoxide tetrabutoxide and monolauryl and monolauryl and
monolauryl Phosphate phosphate phosphate Mixing proportion of 2.0
2.0 2.0 -- titanium compound and phosphorus compound in
polymerization catalyst*.sup.1 Number of fins 3 4 6 4 Protrusion
coefficient 0.51 0.48 0.48 0.48 Crystallinity (%) 21 22 22 20
Boiling water shrinkage 59 56 55 57 ratio (%) Wicking value L.sub.0
(sec) 0 0 0 0 L.sub.10 (sec) 10 3 7 11 Height of spinneret 3.0 2.5
3.7 89 accumulation after 7 days of spinning (.mu.m) Spinning yarn
breakage 0.3 0.5 1.0 5.4 during 7 days (%) Fluff count (/10.sup.4
m) 2 3 1 31 Draw-false twisting yarn 3.2 3.4 4.2 25.4 breakage (%)
(L* - b*) 88 97 95 92 Grading of fabric hand Level 1 Level 1 Level
1 Level 1 *.sup.1Molar ratio of phosphorus atoms with respect to
titanium atoms.
Examples 10-11
[0249] After charging 0.009 part by mass of tetra-n-butyl titanate
(TBT) into a mixture of 100 parts by mass of dimethyl terephthalate
and 70 parts by mass of ethylene glycol in a pressure
reaction-capable stainless steel reactor, pressurization was
conducted at 0.07 MPa for transesterification reaction while
increasing the temperature from 140.degree. C. to 240.degree. C.,
and then 0.035 part by mass of triethyl phosphonoacetate (TEPA) was
added to terminate the transesterification reaction.
[0250] The reaction product was then transferred to a
polymerization reactor, the temperature was raised to 290.degree.
C., and polycondensation reaction was conducted in a high vacuum of
no greater than 26.67 Pa, to obtain polyethylene terephthalate with
an intrinsic viscosity of 0.630 and a diethylene glycol content of
1.5%. The obtained polyethylene terephthalate was then pelleted
according to a common method.
[0251] Separately, a spinneret was prepared beforehand based on a
type of discharge hole with the discharge hole shape shown in FIG.
4, having 24 discharge hole groups each consisting of a
core-forming round discharge hole (b.sub.2 in FIG. 4) with a radius
of 0.15 mm and fin-forming discharge holes with a slit width of
0.10 mm and a length of 0.88 mm from the center of the round
discharge hole to the tip (a.sub.2 in FIG. 4) in the number shown
in Table 1, and it was incorporated into a spin pack and packed
into a spin block. The aforementioned polyethylene terephthalate
pellets were dried at 150.degree. C. for 5 hours and then melted
with a melt spinning apparatus equipped with a screw-type extruder,
introduced into the spin block at 295.degree. C., and extruded from
the spinneret at a discharge rate of 40 g/min. Next, cooling air at
25.degree. C. was blown into the polymer flow at proportion of 5
Nm.sup.3/min from a cross-flow type spinning stack with a length of
60 cm situated with its top 10 cm below the spinneret discharge
plane, for cooling to solidification, after which a spinning
lubricant was applied and the filament was wound up at a speed of
3000 m/min to obtain polyethylene terephthalate filaments each
having the crystallinity, boiling water shrinkage ratio, number of
fins and protrusion coefficient shown in Table 4. This melt
spinning procedure was carried out continuously for 7 days.
[0252] The obtained polyethylene terephthalate filaments were
supplied to an SDS-8 draw-false twisting machine by Scragg Co.
(triple-axle disc false twisting unit, 216 spindles), for
draw-false twisting at a draw ratio of 1.65, a heater temperature
of 175.degree. C., a twist number of 3300/m and a draw-false
twisting speed of 600 m/min, to obtain polyethylene terephthalate
draw-false twisted yarn with a size of 84 dtex. The wicking values
(L.sub.0 and L.sub.10), fabric hands, working yarn breakages and
working fluff counts for Examples 1-3 and Comparative Example 1 are
summarized in Table 4.
Comparative Example 7
[0253] After charging 0.064 part by mass by weight of calcium
acetate monohydrate into a mixture of 100 parts by mass of dimethyl
terephthalate and 70 parts by mass of ethylene glycol in a pressure
reaction-capable stainless steel reactor, pressurization was
conducted at 0.07 MPa for transesterification reaction while
increasing the temperature from 140.degree. C. to 240.degree. C.,
and then 0.044 part by mass of a 56 wt % aqueous phosphoric acid
solution was added to terminate the transesterification
reaction.
[0254] The reaction product was then transferred to a
polymerization reactor, diantimony trioxide was added in the amount
shown in the table, the temperature was raised to 290.degree. C.,
and polycondensation reaction was conducted in a high vacuum of no
greater than 26.67 Pa to obtain polyethylene terephthalate with an
intrinsic viscosity of 0.630. The obtained polyethylene
terephthalate was then pelleted according to a common method.
[0255] The same procedure was carried out as in Example 2, except
for using these polyethylene terephthalate pellets. The results are
shown in Table 4. TABLE-US-00004 TABLE 4 Example Example Example
Comp. 10 11 12 Ex. 7 Ti Type TBT TBT TBT -- compound Content 5 5 5
-- (mmol %) P Type TEPA TEPA TEPA -- compound Content 30 30 30 --
(mmol %) Sb Type -- -- -- Sb.sub.2O.sub.3 compound Content -- -- --
31 (mmol %) P/Ti 6 6 6 -- P + Ti (mmol %) 35 35 35 -- Number of
fins 3 4 6 4 Protrusion coefficient 0.51 0.48 0.48 0.48
Crystallinity (%) 24 25 25 20 Boiling water shrinkage 53 52 52 57
ratio (%) Wicking value L.sub.0 (sec) 0 0 0 0 L.sub.10 (sec) 8 4 6
11 Height of spinneret 5.4 3.6 8.1 89 accumulation after 7 days of
spinning (.mu.m) Spinning yarn breakage 1.4 0.3 2.5 5.4 during 7
days (%) Fluff count (/10.sup.4 m) 1 1 0 31 Draw-false twisting
yarn 3.5 3.9 4.0 25.4 breakage (%) (L* - b*) 90 96 91 88 Grading of
fabric hand Level 1 Level 1 Level 1 Level 1
[0256] The present invention will now be further explained by
Examples 13-34 and Comparative Examples 8-11. The parameters for
these examples and comparative examples were measured by the
following methods.
[0257] (1) Cross-Sectional Shape of Filaments
[0258] The core cross-sectional area (S.sub.A) and diameter
(D.sub.A) and the fin cross-sectional area (S.sub.B) and maximum
length and maximum width (W.sub.B) were determined by observation
of a 3000.times. magnification photograph of the filament
cross-section before alkali reduction.
[0259] (2) Spinning Property
[0260] Spinning was carried out continuously for 8 hours, and was
judged as "A" if absolutely no yarn breakage occurred, "B" if
single filament breakage (fluff) occurred and "C" if yarn breakage
occurred.
[0261] (3) Fin Separation (S)
[0262] The number of separated fins was determined by observation
of a 1000.times. magnification photograph of the filament after
alkali reduction treatment, and the separation rates S (%) of the
fins in the multifilament yarn surface layer portion and center
portion were calculated by the following formula. S (%)=(number of
separated fins/total number of fins).times.100
[0263] (4) Woven/Knitted Fabric Hand
[0264] The bulk, soft feel and drape property of the woven or
knitted fabric were assigned an overall organoleptic evaluation on
a scale of A (very good) to E (poor).
[0265] (5) Compatibility Parameter .chi.
[0266] The solubility parameters .delta.a and .delta.b of the
polyester and of the compound in microphase separation with the
polyester were determined from their solubilities in different
solvents, and .chi. was determined by the following formula.
.chi.=(V.sub.a/RT)(.delta.a-.delta.b).sup.2 (where V.sub.a
represents the molar volume (cm.sup.3/mol) of the polyester, R
represents the gas constant (J/molK), T represents the absolute
temperature (K) and .delta.a and .delta.b represent the solubility
parameters (J.sup.1/2/cm.sup.3/2) of the polyester and compound,
respectively)
[0267] (6) Height of Spinneret Accumulation
[0268] After melt spinning with the method and conditions described
in each example, a release agent was blown onto the spinneret
surface, the spinneret was detached while avoiding adhesion of the
discharge polymer, and the height of spinneret accumulation which
had adhered and accumulated around the discharge hole was measured
using a microscope. The heights of spinneret accumulation were
measured for all of the discharge holes, and their average value
was recorded.
Examples 13-21
[0269] To a stirred mixture of 919 g of ethylene glycol and 10 g of
acetic acid there was added 71 g of titanium tetrabutoxide to
obtain a (transparent) solution of a titanium compound in ethylene
glycol. After then adding 34.5 g of monolauryl phosphate to 656 g
of ethylene glycol heated and stirred at 100.degree. C., heating
and stirring were continued for mixture to dissolution to obtain a
transparent solution.
[0270] Next, both solutions were mixed by stirring at 100.degree.
C., and after adding the entire amounts, the resulting mixture was
stirred at a temperature of 100.degree. C. for 1 hour to obtain a
turbid solution. The mixing ratio of the two solutions was adjusted
for a phosphorus atom molar ratio of 2.0 with respect to titanium
atoms. The obtained white precipitate was filtered out and then
washed with water and dried as the polymerization catalyst.
[0271] A slurry prepared by mixing 179 parts by mass of high-purity
terephthalic acid and 95 parts by mass of ethylene glycol was
supplied at a constant rate into a reactor capable of holding 225
parts by mass of oligomer while stirring in a nitrogen atmosphere
and maintaining conditions of 255.degree. C., ordinary pressure,
and esterification reaction was conducted while distilling out of
the system the water and ethylene glycol generated by the reaction,
until completion of the reaction. The esterification rate was
.gtoreq.98%, and the polymerization degree of the produced oligomer
was approximately 5-7.
[0272] After transferring 225 parts by mass of the oligomer
obtained by the esterification reaction into a polycondensation
reactor, 3.34 parts by mass of the catalyst prepared above was
charged in as the polycondensation catalyst and a compound for
microphase separation with the polyester was added and mixed
therewith, after which the pressure was further reduced to 1 mmHg
for polymerization according to the common method described below,
and pellets were cut to obtain particles of polyethylene
terephthalate with an intrinsic viscosity of 0.63 (hereinafter
referred to as "polyethylene terephthalate chips"). The added and
mixed compounds, the .chi. values of the compounds and their
addition amounts are shown in Table 5.
[0273] These polyethylene terephthalate chips were melt discharged
at 275.degree. C. from a spinneret provided with 24 sets of
discharge holes having the shape shown in FIG. 6B, and cooling was
accomplished in a cross-blowing spinning stack while joining the
obtained cores and fins, followed by winding up at a speed of 1000
m/min.
[0274] The wound up filament yarn was subjected to drawing heat
treatment at a draw ratio of 2.55 using a drawing machine equipped
with a 90.degree. C. hot roller and a 150.degree. C. slit heater,
to obtain 60 dtex/24 filament yarn.
[0275] The obtained filament yarn was formed into a 20 gauge
tube-knit fabric, and the tube-knit fabric was boiled for 20
minutes in a 40 g/liter aqueous sodium hydroxide solution for
alkali reduction treatment.
[0276] The spinning property, height of spinneret accumulation,
fabric hand, etc. for each example are shown in Table 5.
Comparative Examples 8, 9
[0277] Polyethylene terephthalate chips were produced in the same
manner as Examples 15 and 18, except for using antimony trioxide as
the polymerization catalyst, and these were used to produce
filament yarn for Comparative Examples 8 and 9. The spinning
property, height of spinneret accumulation, fabric hand, etc. for
each example are shown in Table 5. TABLE-US-00005 TABLE 5 Fin
separation Surface Addition Accumulation layer Center amount Number
Spinning height section section Fabric Compound .chi. (wt %) of
fins S.sub.B/S.sub.A L.sub.B/D.sub.A W.sub.B/D.sub.A property
(.mu.m) (%) (%) hand Example 13 PEG 0.08 3.0 4 1/4 1.0 1/5 A 12 62
44 B Example 14 PEG 0.08 3.0 6 1/4 0.8 1/5 A 9 66 47 A Example 15
C.sub.16H.sub.31-grafted PEG 0.25 3.0 4 1/4 1.0 1/5 A 10 72 51 A
Example 16 PE(30)-PMMA(70) 0.33 3.0 4 1/4 1.0 1/5 A 13 78 59 A
copolymer Example 17 PE(90)-PMMA(10) 1.3 3.0 4 1/4 1.0 1/5 A 12 89
68 A copolymer Example 18 PE 2.2 3.0 4 1/4 1.0 1/5 A 14 70 52 B
Example 19 PMMA 2.3 3.0 4 1/4 1.0 1/5 A 21 71 54 B Example 20
C.sub.16H.sub.31-grafted PEG 0.25 0.3 4 1/4 1.0 1/5 A 17 63 41 B
Example 21 C.sub.16H.sub.31-grafted PEG 0.25 4.0 4 1/3 1.5 1/4 A 15
79 60 A Comp. Ex. 8 C.sub.16H.sub.31-grafted PEG 0.25 3.0 4 1/4 1.0
1/5 B 55 70 53 A Comp. Ex. 9 PE 2.2 3.0 4 1/4 1.0 1/5 C 61 71 53
B
Examples 22, 23
[0278] For Example 22, filament yarn A obtained in Example 15 and a
40 dtex/18 filament yarn B obtained by melt discharging
polyethylene terephthalate chips from a spinneret provided with 18
sets of flat discharge holes (L/D=5), winding up at 1500 m/min and
then drawing at a preheating temperature of 90.degree. C. and a
draw ratio of 2.7, were entangled with an interlace nozzle at an
air pressure of 1.5 kg/cm.sup.2 and an overfeed rate of 1.5%, to
produce combined filament yarn.
[0279] This combined filament yarn was twisted at S300T/M and used
as warp yarn and weft yarn for weaving of a habutae woven fabric.
After relaxation treatment, the fabric was heat set and then
subjected to 20% alkali reduction treatment. Table 6 shows the
shrinkage ratios and combination ratio for filament yarn A and
filament yarn B, as well as the fin separation in the woven fabric
and the fabric hand.
[0280] For Example 23, polyethylene terephthalate chips with an
intrinsic viscosity of 0.64 containing titanium oxide at 0.05 wt %
as a delustering agent were melt discharged at 275.degree. C. from
a spinneret provided with 24 sets of discharge holes each having
the shape shown in FIG. 6B, and cooling was accomplished in a
cross-blowing spinning stack while joining the discharged cores and
fins, followed by winding up at a speed of 2500 m/min, and after
subsequent drawing at a preheating temperature of 90.degree. C. and
a draw ratio of 1.8, relaxation heat treatment was carried out
using a non-contact heater at 150.degree. C. with an overfeed rate
of 2% to obtain a 60 dtex/24 filament yarn A.
[0281] Separately, the polyethylene terephthalate chips were melt
discharged from a spinneret having 18 round discharge holes, wound
up at 1500 m/min and drawn at a preheating temperature of
90.degree. C. and a draw ratio of 3.0 to obtain a 40 dtex/18
filament yarn B.
[0282] The filament yarn A and filament yarn B were combined and
used for weaving and alkali reduction treatment by the same methods
as in Example 23.
[0283] Table 6 shows the shrinkage ratios and combination ratio for
filament yarn A and filament yarn B obtained in Examples 22 and 23,
as well as the fin separation in the resulting woven fabric and the
fabric hand. The combination ratio is the ratio of filament yarn A
combined with respect to the entire combined filament yarn (weight
of filament yarn A+weight of filament yarn B). TABLE-US-00006 TABLE
6 Filament A Filament B Boiling Boiling Fin separation water Dry
heat water Surface shrinkage shrinkage Combination shrinkage layer
Center ratio ratio ratio ratio section section Fabric (%) (%) (%)
(%) (%) (%) hand Example 22 8 0.5 60 8 53 38 B Example 23 6 -5 54 6
52 37 A
Examples 24-32
[0284] After charging 0.009 part by mass of tetra-n-butyl titanate
(TBT) into a mixture of 100 parts by mass of dimethyl terephthalate
and 70 parts by mass of ethylene glycol in a pressure
reaction-capable stainless steel reactor, pressurization was
conducted at 0.07 MPa for transesterification reaction while
increasing the temperature from 140.degree. C. to 240.degree. C.,
and then 0.035 part by mass of triethyl phosphonoacetate (TEPA) was
added to terminate the transesterification reaction. Here,
M.sub.P/M.sub.Ti=3, M.sub.P+M.sub.Ti=35.
[0285] The reaction product was then transferred to a
polymerization reactor, the temperature was raised to 290.degree.
C., and polycondensation reaction was conducted in a high vacuum of
no greater than 26.67 Pa to obtain polyethylene terephthalate
having an intrinsic viscosity of 0.63 and a diethylene glycol
content of 1.5%. The obtained polyethylene terephthalate was formed
into chips by an ordinary method.
[0286] The polyethylene terephthalate chips were melt discharged at
275.degree. C. from a spinneret provided with 24 sets of discharge
holes having the shape shown in FIG. 6B, and cooling was
accomplished in a cross-blowing spinning stack while joining the
discharged cores and fins, followed by winding up at a speed of
1000 m/min.
[0287] The wound up filament yarn was subjected to drawing heat
treatment at a draw ratio of 2.55 using a drawing machine equipped
with a 90.degree. C. hot roller and a 150.degree. C. slit heater,
to obtain 60 dtex/24 filament yarn.
[0288] The obtained filament yarn was formed into a 20 gauge
tube-knit fabric, and the tube-knit fabric was boiled for 20
minutes in a 40 g/liter aqueous sodium hydroxide solution for
alkali reduction treatment.
[0289] The spinning property, height of spinneret accumulation,
fabric hand, etc. for each example are shown in Table 7.
Comparative Examples 10, 11
[0290] After charging 0.064 part by mass by weight of calcium
acetate monohydrate into a mixture of 100 parts by mass of dimethyl
terephthalate and 70 parts by mass of ethylene glycol in a pressure
reaction-capable stainless steel reactor, pressurization was
conducted at 0.07 MPa for transesterification reaction while
increasing the temperature from 140.degree. C. to 240.degree. C.,
and then 0.044 part by mass of a 56 wt % aqueous phosphoric acid
solution was added to terminate the transesterification
reaction.
[0291] The reaction product was then transferred to a
polymerization reactor, diantimony trioxide was added in the amount
shown in the table, the temperature was raised to 290.degree. C.,
and polycondensation reaction was conducted in a high vacuum of no
greater than 26.67 Pa to obtain polyethylene terephthalate. The
obtained polyethylene terephthalate was formed into chips by an
ordinary method.
[0292] Filament yarn was produced in the same manner as Examples 26
and 29, except for using the above-mentioned polyethylene
terephthalate chips, and these were used for Comparative Examples
10 and 11. The spinning property, height of spinneret accumulation,
fabric hand, etc. for each example are shown in Table 7.
TABLE-US-00007 TABLE 7 Ti compound P compound Sb compound Addition
Number Content Content Content amount of Compound Type mmol % Type
mmol % Type mmol % .chi. wt % fins Example PEG TBT 5 TEPA 30 -- --
0.08 3.0 4 24 Example PEG TBT 5 TEPA 30 -- -- 0.08 3.0 6 25 Example
C.sub.16H.sub.31- TBT 5 TEPA 30 -- -- 0.25 3.0 4 26 grafted PEG
Example PE(30)- TBT 5 TEPA 30 -- -- 0.33 3.0 4 27 PMMA(70)
copolymer Example PE(90)- TBT 5 TEPA 30 -- -- 1.3 3.0 4 28 PMMA(10)
copolymer Example PE TBT 5 TEPA 30 -- -- 2.2 3.0 4 29 Example PMMA
TBT 5 TEPA 30 -- -- 2.3 3.0 4 30 Example C.sub.16H.sub.31- TBT 5
TEPA 30 -- -- 0.25 0.3 4 31 grafted PEG Example C.sub.16H.sub.31-
TBT 5 TEPA 30 -- -- 0.25 4.0 4 32 grafted PEG Comp.
C.sub.16H.sub.31- -- -- -- -- Sb.sub.2O.sub.3 31 0.25 3.0 4 Ex. 10
grafted PEG Comp. PE -- -- -- -- Sb.sub.2O.sub.3 31 2.2 3.0 4 Ex.
11 Fin separation Accumulation Surface Spinning height layer Center
Fabric S.sub.B/S.sub.A L.sub.B/D.sub.A W.sub.B/D.sub.A property
.mu.m section % section % hand Example 1/4 1.0 1/5 A 10 63 40 B 24
Example 1/4 0.8 1/5 A 8 67 46 A 25 Example 1/4 1.0 1/5 A 10 71 52 A
26 Example 1/4 1.0 1/5 A 12 77 61 A 27 Example 1/4 1.0 1/5 A 11 86
67 A 28 Example 1/4 1.0 1/5 A 14 71 52 B 29 Example 1/4 1.0 1/5 A
22 70 53 B 30 Example 1/4 1.0 1/5 A 16 66 43 B 31 Example 1/3 1.5
1/4 A 16 80 59 A 32 Comp. 1/4 1.0 1/5 B 57 71 52 A Ex. 10 Comp. 1/4
1.0 1/5 C 65 73 52 B Ex. 11
Examples 33, 34
[0293] For Example 33, filament yarn A obtained in Example 26 and a
40 dtex/18 filament yarn B obtained by melt discharging
polyethylene terephthalate chips from a spinneret provided with 18
sets of flat discharge holes (L/D=5), winding up at 1500 m/min and
then drawing at a preheating temperature of 90.degree. C. and a
draw ratio of 2.7, were entangled with an interlace nozzle at an
air pressure of 1.5 kg/cm.sup.2 and an overfeed rate of 1.5%, to
produce combined filament yarn.
[0294] This combined filament yarn was twisted at S300T/M and used
as warp yarn and weft yarn for weaving of a habutae woven fabric.
After relaxation treatment, the fabric was heat set and then
subjected to 20% alkali reduction treatment. Table 8 shows the
shrinkage ratios and combination ratio for filament yarn A and
filament yarn B, as well as the fin separation in the woven fabric
and the fabric hand.
[0295] For Example 34, polyethylene terephthalate chips with an
intrinsic viscosity of 0.64 containing titanium oxide at 0.05 wt %
as a delustering agent were melt discharged at 275.degree. C. from
a spinneret provided with 24 sets of discharge holes having the
shape shown in FIG. 6B, and cooling was accomplished in a
cross-blowing spinning stack while joining the discharged cores and
fins, followed by winding up at a speed of 2500 m/min, and after
subsequent drawing at a preheating temperature of 90.degree. C. and
a draw ratio of 1.8, relaxation heat treatment was carried out
using a non-contact heater at 150.degree. C. with an overfeed rate
of 2% to obtain a 60 dtex/24 filament yarn A.
[0296] Separately, the polyethylene terephthalate chips were melt
discharged from a spinneret having 18 round discharge holes, wound
up at 1500 m/min and drawn at a preheating temperature of
90.degree. C. and a draw ratio of 3.0 to obtain a 40 dtex/18
filament yarn B.
[0297] The filament yarn A and filament yarn B were combined and
used for weaving and alkali reduction treatment by the same methods
as in Example 33.
[0298] Table 8 shows the shrinkage ratios and combination ratio for
filament yarn A and filament yarn B obtained in Examples 33 and 34,
as well as the fin separation in the resulting woven fabric and the
fabric hand. TABLE-US-00008 TABLE 8 Multifilament A Multifilament B
Boiling Boiling Fin separation water Dry heat water Surface
shrinkage shrinkage Combination shrinkage layer Center ratio ratio
ratio ratio section section Fabric (%) (%) (%) (%) (%) (%) hand
Example 33 8.3 0.6 60 15.6 50 35 B Example 34 6.1 -4.0 54 16.1 56
39 A
[0299] The present invention will now be further explained by
Examples 35-40 and Comparative Examples 12-13. The parameters for
these examples were measured by the following methods.
[0300] (1) Intrinsic Viscosity
[0301] This was measured at 35.degree. C. using orthochlorophenol
as the solvent.
[0302] (2) Polymer Discharge State
[0303] The discharge state of the polymer when discharged from the
spinneret was observed during spinning, and the discharge state was
ranked on the following scale. Observation was from the 1st hour,
3rd day and 7th day after the start of conjugate spinning.
Level 1: Discharged filament drew a consistent falling line with
stable running
Level 2: Small bends, kinks or swirls in discharged filament
Level 3: Large bends, kinks or swirls in discharged filament.
Partial contact of polymer with spinneret surface, resulting in
frequent filament breakage.
[0304] (3) Hollowness (%)
[0305] The hollow section area (A) of each single fiber
cross-section and the area (B) surrounding the cross-section were
measured from a micrograph of the polyester fiber cross-sections,
and the average value for all of the single fiber lateral
cross-sections calculated by the following formula was recorded as
the hollowness (%) Hollowness (%)=A/B.times.100
[0306] (4) Size Irregularity (U %)
[0307] This was measured using a USTER TESTER-4 by Zellweger Uster,
with a running speed of 400 m/min.
[0308] (5) Fluff Count (/10.sup.6 m)
[0309] Upon placing 250 package-wound (or pirn-wound) polyester
fibers through a warping machine equipped with a fluff detector,
the yarns were warped and drawn for 42 hours at a speed of 400
m/min. The warping machine was periodically shut down and the
presence of fluff visually confirmed, and the total confirmed fluff
count was calculated per 10.sup.6 m of the strand length and
recorded as the fluff count.
[0310] (6) Dye Spots
[0311] The polyester fibers were knitted to a 30 cm long tube knit
with a 12-gauge circular knitting machine, a dye (Terasil Blue GFL)
was used for dyeing at 100.degree. C. for 40 minutes, and the level
dyeing property was graded on the following scale based on visual
examination by an examiner.
Level 1: Uniform dyeing, virtually no dye spots
Level 2: Some striped or spotted dye spots
Level 3: Significant striped or spotted dye spots on one side.
[0312] (7) Tenacity and Elongation
[0313] These were measured according to JIS-L1013.
[0314] (8) Hand
[0315] The squeaky feel, bulk, flexibility and lightweight feel
were ranked on a three-level scale of very good (excellent), good
(satisfactory) or poor (unacceptable) by a panel of 5 experts, and
the average values were calculated.
Example 35
[0316] Preparation of a titanium compound, phosphorus compound and
catalyst and production of an oligomer were carried out in the same
manner as Example 1.
[0317] After transferring 225 parts by mass of the oligomer
obtained by esterification reaction to a polycondensation reactor,
3.34 parts by mass of the "TP1-2.0 catalyst" produced earlier was
charged in as the polycondensation catalyst. The reaction
temperature in the system was then raised from 255.degree. C. to
280.degree. C. and the reaction pressure was lowered from
atmospheric pressure to 60 Pa in stages, for polycondensation
reaction while removing out of the system the water and ethylene
glycol generated by the reaction, and then 0.6 wt % of a C8-20
(average=C14) sodium alkylsulfonate was added, and after completion
of the reaction, the reaction product in the system was
continuously extruded from the discharge port into a strand form
and cooled and cut to obtain granular pellets approximately 3 mm in
size. The intrinsic viscosity of the obtained polyethylene
terephthalate was 0.63.
[0318] After drying the obtained polyester pellets by an ordinary
method, they were introduced into a spinning machine equipped with
a melt extruder (screw extruder) and melted, subsequently
introduced into a spinning pack placed in a spin block held at
290.degree. C. and then melt discharged, and the discharged
filament was cooled to solidification, after which a lubricant was
applied thereto prior to interlacing and then winding up at a
take-up speed of 1400 m/min. The obtained undrawn filament was
drawn at a preheating roller temperature of 90.degree. C., a heat
setting heater (non-contact type) temperature of 200.degree. C., a
draw ratio of 2.3 and a drawing speed of 800 m/min, and finally
interlaced to obtain 83 dtex/24 filament polyester modified
cross-section fibers with a hollowness of 15%. No accumulation of
foreign matter was found around the spinneret discharge holes
during spinning, and the polymer discharge state was stable for an
extended period.
[0319] The obtained filaments were used as warp yarn and weft yarn
for weaving of a habutae woven fabric, and then scouring, heat
setting, alkali reduction (reduction rate: 15%) and dyeing were
carried out by ordinary methods to obtain a plain dyed woven
fabric. The evaluation results for the obtained fibers and woven
fabric are shown in Table 9.
Comparative Example 12
[0320] The same procedure was carried out as in Example 35, except
that the polycondensation catalyst was changed to a 1.3% solution
of antimony trioxide in ethylene glycol, the charged amount was
4.83 parts by mass, and there was further charged 0.121 part by
mass of a 25% solution of trimethyl phosphate in ethylene glycol as
a stabilizer, to obtain a polyester with an intrinsic viscosity of
0.63. The polyester was spun and drawn with the same method and
conditions as in Example 1 to obtain 83 dtex/24 filament polyester
modified cross-section fibers. Growth of accumulated matter was
found around the spinneret discharge holes during the course of
spinning, while bends, kinks and swirls were also observed in the
discharged filaments. A dyed woven fabric was also obtained in the
same manner as Example 1. The results for the obtained fibers and
fabric are shown in Table 9. TABLE-US-00009 TABLE 9 Example 35
Comp. Ex. 12 Polycondensation catalyst TP1-2.0 Sb.sub.2O.sub.3
Polymer discharge state (level) After 1 hr spinning 1 2 After 3
days spinning 1 3 After 7 days spinning 1 3 Size irregularity (U %)
After 1 hr spinning 0.6 0.8 After 3 days spinning 0.5 1.2 After 7
days spinning 0.5 1.8 Fluff count (/10.sup.6 m) After 1 hr spinning
0.06 1.1 After 3 days spinning 0.07 2.5 After 7 days spinning 0.07
3.2 Dye spots (level) After 1 hr spinning 1 2 After 3 days spinning
1 3 After 7 days spinning 1 3 Hand excellent excellent Tenacity
(cN/dtex) 2.2 2.1 Elongation (%) 33 32
Examples 36-37
[0321] Spinning and drawing were carried out with the same method
and conditions as in Example 35, except that the single fiber
lateral cross-sectional shapes had the values shown in Table 10, to
obtain polyester modified cross-section fibers. Dyed woven fabrics
were also obtained in the same manner as Example 35. The hands of
the obtained woven fabrics are shown in Table 10.
Comparative Example 13
[0322] Spinning and drawing were carried out with the same method
and conditions as in Example 35, except that the single fiber
lateral cross-sectional shape was a round cross-section, to obtain
polyester fibers. A dyed woven fabric was also obtained in the same
manner as Example 35. The hand of the obtained woven fabric is
shown in Table 10 (absolutely no squeaky feel was exhibited).
TABLE-US-00010 TABLE 10 Example 36 Example 37 Comp. Ex. 13 L1/L2
2.0 0.8 -- h2/h1 5.3 5.3 -- Hand excellent excellent poor
Examples 38-40
[0323] Spinning and drawing were carried out with the same method
and conditions as in Example 35, except that the hollowness values
for the fibers were as shown in Table 11, to obtain polyester
modified cross-section fibers. Dyed woven fabrics were also
obtained in the same manner as Example 35. The results for the
obtained fibers and woven fabrics are shown in Table 11.
TABLE-US-00011 TABLE 11 Example 38 Example 39 Example 40 Hollowness
(%) 3 8 13 Polymer discharge state (level) After 1 hr spinning 1 1
1 After 3 days spinning 1 1 1 After 7 days spinning 1 1 1 Size
irregularity (U %) After 1 hr spinning 0.5 0.4 0.4 After 3 days
spinning 0.5 0.3 0.4 After 7 days spinning 0.5 0.4 0.4 Fluff count
(/10.sup.6 m) After 1 hr spinning 0.05 0.04 0.05 After 3 days
spinning 0.05 0.03 0.04 After 7 days spinning 0.04 0.04 0.05 Dye
spots (level) After 1 hr spinning 1 1 1 After 3 days spinning 1 1 1
After 7 days spinning 1 1 1 Hand excellent excellent excellent
Tenacity (cN/dtex) 2.6 2.2 1.8 Elongation (%) 39 33 24
* * * * *