U.S. patent application number 15/502654 was filed with the patent office on 2017-08-17 for glossy pilling-resistant acrylic fiber, method for producing same, and spun yarn and knitted fabric containing said acrylic fiber.
This patent application is currently assigned to Mitsubishi Rayon Co., Ltd.. The applicant listed for this patent is MITSUBISHI RAYON CO., LTD.. Invention is credited to Hideto DAN, Tatsuhiko INAGAKI, Shingo NAKAHASHI, Shima NAKANISHI, Yukio ONOHARA.
Application Number | 20170233897 15/502654 |
Document ID | / |
Family ID | 55399706 |
Filed Date | 2017-08-17 |
United States Patent
Application |
20170233897 |
Kind Code |
A1 |
NAKANISHI; Shima ; et
al. |
August 17, 2017 |
GLOSSY PILLING-RESISTANT ACRYLIC FIBER, METHOD FOR PRODUCING SAME,
AND SPUN YARN AND KNITTED FABRIC CONTAINING SAID ACRYLIC FIBER
Abstract
The present invention provides: an acrylic fiber having a
fineness of 0.5 to 3.5 dtex and having excellent gloss, pilling
resistance, and texture; a method for producing said acrylic fiber;
and a spun yarn and a knitted fabric containing said acrylic fiber.
Provided is an acrylic fiber having a filament fineness of 0.5 to
3.5 dtex, wherein the product K of the value of knot strength
(cN/dtex) and the value of knot elongation (%) is from 8 to 30
inclusive, and the number of recesses having a depth of 0.1 .mu.m
or greater is 10 or fewer.
Inventors: |
NAKANISHI; Shima;
(Otake-shi, JP) ; DAN; Hideto; (Otake-shi, JP)
; NAKAHASHI; Shingo; (Otake-shi, JP) ; ONOHARA;
Yukio; (Otake-shi, JP) ; INAGAKI; Tatsuhiko;
(Otake-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MITSUBISHI RAYON CO., LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
Mitsubishi Rayon Co., Ltd.
Tokyo
JP
|
Family ID: |
55399706 |
Appl. No.: |
15/502654 |
Filed: |
August 25, 2015 |
PCT Filed: |
August 25, 2015 |
PCT NO: |
PCT/JP2015/073883 |
371 Date: |
February 8, 2017 |
Current U.S.
Class: |
428/219 |
Current CPC
Class: |
D10B 2401/20 20130101;
D01F 6/38 20130101; D04B 21/00 20130101; D10B 2321/10 20130101;
D01F 6/18 20130101; D01D 5/12 20130101 |
International
Class: |
D01F 6/18 20060101
D01F006/18; D04B 21/00 20060101 D04B021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 27, 2014 |
JP |
2014-172129 |
Claims
1. An acrylic fiber, configured to have a center-line mean
roughness (Ra) of 3 nm to 12 nm on the surface of a single fiber,
and a single fiber fineness of 0.5 dtex to 3.5 dtex.
2. An acrylic fiber, configured to have a center-line mean
roughness (Ra) of 3 nm to 12 nm on the surface of a single fiber,
and a product (K) of 10 to 30 obtained by multiplying the value of
knot strength (cN/dtex) and the value of knot elongation (%).
3. The acrylic fiber according to claim 1, wherein the value of a
product (K), obtained by multiplying the value of knot strength
(cN/dtex) and the value of knot elongation (%), is set to be 10 to
30.
4. The acrylic fiber according to claim 2, wherein a single fiber
fineness is set at 0.5 dtex to 3.5 dtex.
5. The acrylic fiber according to claim 1, wherein the surface of a
single fiber is configured to have a maximum height (Ry) of the
profile set at 40 nm to 150 nm, the 30-point mean roughness (Rz) at
20 nm to 80 nm and the distance (S) between peaks of convex
portions at 800 nm to 1100 nm.
6. The acrylic fiber according to claim 1, wherein the number of
recesses of 0.1 .mu.m or deeper that are present on the surface of
a single fiber is no greater than 10 when observed in a cross
section perpendicular to the fiber axis.
7. The acrylic fiber according to claim 1, comprising 92 mass % to
96.8 mass % of an acrylonitrile unit, 2 mass % to 6 mass % of a
vinyl monomer unit, and 0.2 mass % to 2.0 mass % of a sulfonic acid
group-containing vinyl monomer unit, wherein a single fiber tensile
strength is set at 1.8 cN/dtex to 3.0 cN/dtex, a single fiber knot
strength is set at 1.0 cN/dtex to 1.8 cN/dtex, and a single fiber
knot elongation is set at 8% to 20%.
8. A method for producing an acrylic fiber, comprising: forming a
spinning dope by dissolving in an organic solvent an
acrylonitrile-based copolymer that contains 92 mass % to 96.8 mass
% of an acrylonitrile unit and 0.2 mass % to 2.0 mass % of a
sulfonic acid group containing-vinyl monomer unit; forming a
coagulated fiber bundle by discharging the spinning dope in a
35.degree. C. to 50.degree. C. coagulation bath through the
discharge ports of a spinning nozzle at a jet-stretch ratio of 0.4
to 2.2; stretching the coagulated fiber bundle in 80.degree. C. to
98 C..degree. hot water at a stretch ratio of 2 to 3.8 times;
applying oil to the fiber bundle and drying the fiber bundle; and
stretching the fiber bundle by applying dry heat to have a fiber
temperature of 150.degree. C. to 170.degree. C. at a stretch ratio
of 1.2 to 3 times, wherein the value of a product (S), obtained by
multiplying the hot-water stretch ratio and the dry-heat stretch
ratio, is set to be 4 to 6.
9. The method for producing an acrylic fiber according to claim 8,
wherein the acrylonitrile-based copolymer is configured to further
comprise 2 mass % to 6 mass % of a vinyl monomer unit, the solvent
concentration of the coagulation bath is set to be 40 mass % to 60
mass %, and a thermal relaxation process is conducted after hot-dry
stretching.
10. The method for producing an acrylic fiber according to claim 8,
wherein the temperature for the thermal relaxation process is set
at 120.degree. C. to 135.degree. C., and a fiber relaxation ratio
is set at 5% to 20%.
11. A spun yarn, comprising: an acrylic fiber according to claim 1
at 40 mass % or greater, wherein the cotton count is set at 40 to
70.
12. The spun yarn according to claim 11, further comprising a
cellulose-based fiber at 10 mass % to 40 mass %.
13. A knitted fabric, comprising: a spun yarn according to claim 11
at 40 mass % or greater, wherein the basis weight is set at 150
g/m.sup.2 to 230 g/m.sup.2, and the pilling-resistant property is
rated at 4 or higher.
14. The knitted fabric according to claim 13, wherein a
heat-retention rate is set to be 15% to 50%.
15. The acrylic fiber according to claim 2, wherein the surface of
a single fiber is configured to have a maximum height (Ry) of the
profile set at 40 nm to 150 nm, the 30-point mean roughness (Rz) at
20 nm to 80 nm and the distance (S) between peaks of convex
portions at 800 nm to 1100 nm.
16. The acrylic fiber according to claim 2, wherein the number of
recesses of 0.1 .mu.m or deeper that are present on the surface of
a single fiber is no greater than 10 when observed in a cross
section perpendicular to the fiber axis.
17. The acrylic fiber according to claim 2, comprising 92 mass % to
96.8 mass % of an acrylonitrile unit, 2 mass % to 6 mass % of a
vinyl monomer unit, and 0.2 mass % to 2.0 mass % of a sulfonic acid
group-containing vinyl monomer unit, wherein a single fiber tensile
strength is set at 1.8 cN/dtex to 3.0 cN/dtex, a single fiber knot
strength is set at 1.0 cN/dtex to 1.8 cN/dtex, and a single fiber
knot elongation is set at 8% to 20%.
18. A spun yarn, comprising: an acrylic fiber according to claim 2
at 40 mass % or greater, wherein the cotton count is set at 40 to
70.
19. The spun yarn according to claim 18, further comprising a
cellulose-based fiber at 10 mass % to 40 mass %.
20. A knitted fabric, comprising: a spun yarn according to claim 18
at 40 mass % or greater, wherein the basis weight is set at 150
g/m.sup.2 to 230 g/m.sup.2, and the pilling-resistant property is
rated at 4 or higher
Description
TECHNICAL FIELD
[0001] The present invention relates to a pilling-resistant acrylic
fiber that exhibits excellent gloss and soft texture, to a method
for producing the acrylic fiber, and to a spun yarn and a knitted
fabric that contain the acrylic fiber.
BACKGROUND ART
[0002] Acrylic fibers have excellent characteristics such as soft
texture, heat retention capability, shape stability, weather
resistance and dyeability, and are widely used in apparel and
interior applications the same as other synthetic fibers such as
nylon and polyester fibers. However, when fiber products made of
acrylic fibers are in use, pilling tends to occur. Accordingly, the
appearance and texture of knitted fabrics are significantly lowered
and their commercial value is reduced. Therefore, technological
development has been sought for a so-called pilling-resistant
acrylic fiber in which pilling rarely occurs.
[0003] Meanwhile, to achieve softer texture in apparel products,
degrees of fiber fineness have become even smaller recently, and
development of products using fibers with a smaller fiber fineness
is in progress. Since pilling is more likely to occur when the
degree of fiber fineness is smaller, demand for improved
pilling-resistance properties is on the rise.
[0004] In addition to improving the texture of apparel products, it
has been proposed to enhance gloss to express high quality similar
to that of silk. For example, Patent Literature 1 (JP H11-222716A)
proposes an acrylic fiber having a large single fiber fineness of
6.about.34 dtex with a flat cross section, which is set to have
enhanced gloss by forming smooth portions of at least a certain
size on the fiber surface. Patent Literature 2 (JP2012-36512A)
proposes a glossy acrylic fiber which is set to have a circular, or
an elliptical but almost circular, fiber cross section and to have
a recessed curvature on the edge of the cross section. Those fibers
are each set to have a large single fiber fineness of 6 dtex or
greater, while having a flat or broad-bean shaped
cross-section.
[0005] Moreover, Patent Literature 3 (JP2006-176937A) and Patent
Literature 4 (JP2008-38309A) each propose a yarn containing a
pilling-resistant acrylic fiber with a smaller fiber fineness along
with its manufacturing method. However, none of such
smaller-fineness acrylic fibers has achieved both
pilling-resistance and glossy properties.
[0006] Patent Literature 5 (JP2011-12363A) proposes a
carbon-fiber-precursor acrylic fiber which is structured to have
fewer irregularities on fiber surfaces and to have a single fiber
fineness of 1.1 dtex. However, since the strength of the
carbon-fiber-precursor acrylic fiber is enhanced, the knot strength
and knot elongation are smaller. Accordingly, the
carbon-fiber-precursor acrylic fiber tends to break during the
spinning process and thus is not suitable for forming yarn.
CITATION LIST
Patent Literature
[0007] Patent Literature 1: JP H11-222716A
[0008] Patent Literature 2: JP2012-36512A
[0009] Patent Literature 3: JP2006-176937A
[0010] Patent Literature 4: JP2008-38309A
[0011] Patent Literature 5: JP2011-12363A
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0012] Considering the above, the objective of the present
invention is to provide an acrylic fiber with a fiber fineness of
0.5.about.3.5 dtex, which is set to exhibit excellent gloss and
pilling resistance while having soft texture, and to provide its
manufacturing method. The present invention also provides a spun
yarn and knitted product containing such an acrylic fiber.
Solutions to the Problems
[0013] An acrylic fiber related to the present invention is set to
have a center-line mean roughness (Ra) of 3 nm to 12 nm on a single
fiber surface, and a single fiber fineness of 0.5 dtex to 3.5
dtex.
[0014] The acrylic fiber related to the present invention is
preferred to have a product (K) of 10 to 30 obtained by multiplying
the value of knot strength (cN/dtex) and the value of knot
elongation (%).
[0015] The acrylic fiber related to the present invention is
structured to have a center-line mean roughness (Ra) of 3 nm to 12
nm on a single fiber surface, and to have a product (K) of 10 to 30
obtained by multiplying the value of knot strength (cN/dtex) and
the value of knot elongation (%).
[0016] The acrylic fiber related to the present invention is
preferred to have a single fiber fineness of 0.5 dtex to 3.5
dtex.
[0017] On the surface of an acrylic fiber related to the present
invention, it is preferred that a maximum height (Ry) of the
profile be set at 40 nm to 150 nm, a 30-point mean roughness (Rz)
at 20 nm to 80 nm, and a distance (S) at 800 nm to 1100 nm between
peaks of convex portions.
[0018] Regarding the acrylic fiber related to the present
invention, the number of recesses of 0.1 .mu.m or deeper that are
present on the surface of a single fiber is preferred to be no
greater than 10 when counted in the cross section perpendicular to
the fiber axis.
[0019] The acrylic fiber related to the present invention is
preferred to contain 92 mass % to 96.8 mass % of an acrylonitrile
unit, 2 mass % to 6 mass % of a vinyl monomer unit, and 0.2 mass %
to 2.0 mass % of a sulfonic acid group-containing vinyl monomer
unit, and to have a single fiber tensile strength of 1.8 cN/dtex to
3.0 cN/dtex, a single fiber knot strength of 1.0 cN/dtex to 1.8
cN/dtex, and a single fiber knot elongation of 8% to 12%.
[0020] A method for producing acrylic fiber related to the present
invention includes the following steps: forming a spinning dope by
dissolving in an organic solvent an acrylonitrile-based copolymer
that contains 92 mass % to 96.8 mass % of an acrylonitrile unit and
0.2 mass % to 2.0 mass % of a sulfonic acid group-containing vinyl
monomer unit; forming a coagulated fiber bundle by discharging the
spinning dope in a 35.degree. C. to 50.degree. C. coagulation bath
through multiple discharge ports of a spinning nozzle at a
jet-stretch ratio of 0.4 to 2.2 times; stretching the coagulated
fiber bundle in 80.degree. C. to 98.degree. C. hot water at a
stretch ratio of 2 to 3.8 times; applying oil to the fiber bundle
and drying thereafter; stretching the fiber bundle by applying dry
heat to have a fiber temperature of 150.degree. C. to 170.degree.
C. at a stretch ratio of 1.2 to 3 times; and setting the value of a
product (S) to be 4 to 6 when obtained by multiplying the hot-water
stretch ratio and the dry-heat stretch ratio.
[0021] In the method for producing the acrylic fiber related to the
present invention, it is preferred that the acrylonitrile-based
copolymer further contain 2 mass % to 6 mass % of a vinyl monomer
unit, the solvent concentration of the coagulation bath be 40 mass
% to 60 mass %, and a thermal relaxation process be conducted after
hot-dry stretching.
[0022] In the method for producing an acrylic fiber related to the
present invention, the thermal relaxation process is preferred to
have an annealing temperature of 120.degree. C. to 135.degree. C.
and a fiber relaxation ratio of 5% to 20%.
[0023] A spun yarn related to the present invention contains the
acrylic fiber at 40 mass % or greater, and has a cotton count of 40
to 70.
[0024] The spun yarn is preferred to contain a cellulose-based
fiber at 10 mass % to 40 mass %.
[0025] A knitted fabric related to the present invention contains
the spun yarn at 40 mass % or greater, has a basis weight of 150
g/m.sup.2 to 230 g/m.sup.2, and the pilling resistant property is
rated at 4 or higher.
[0026] The knitted fabric related to the present invention is
preferred to exhibit a heat-retention rate of 15% to 50%.
Effects of the Invention
[0027] According to the present invention, an acrylic fiber is
provided to be used in inner apparel applications, especially in
applications for undergarments. Using the acrylic fiber, such fiber
products exhibit a soft texture while showing high-grade gloss and
excellent pilling resistance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a cross-sectional view of a single fiber surface,
showing a center-line mean roughness (R);
[0029] FIG. 2 is a cross-sectional view of a single fiber surface,
showing a maximum height (Ry) of the profile;
[0030] FIG. 3 is a cross-sectional view of a single fiber surface,
showing a 30-point mean roughness (Rz); and
[0031] FIG. 4 is a cross-sectional view of a single fiber surface,
showing a distance (S) between peaks of convex portions.
DETAILED DESCRIPTION OF THE EMBODIMENTS
<Polymer Composition of Acrylic Fiber>
[0032] In the acrylic fiber related to the present invention, the
copolymer is preferred to be formed by copolymerizing 92 mass % to
96.8 mass % of an acrylonitrile unit. When the copolymerization
ratio of an acrylonitrile unit is 92 mass % or greater, it is
easier to obtain the fiber strength required for forming apparel
fibers.
[0033] From the above viewpoint, the ratio of an acrylonitrile unit
in a copolymer is more preferred to be 95 mass % or greater.
[0034] In addition, when the copolymerization ratio of an
acrylonitrile unit is 96.8 mass % or lower, excellent dyeability,
fiber strength and elongation are expected to be achieved.
[0035] In the copolymer, the ratio of a vinyl monomer unit
copolymerizable with acrylonitrile is preferred to be set at 3.0
mass % to 6.0 mass %. When the polymerization ratio of a vinyl
monomer unit is set in such a range, sufficient physical
characteristics and dyeability necessary for knitted products are
achieved.
[0036] Moreover, the copolymerization ratio of a sulfonic acid
group-containing vinyl monomer unit in the copolymer is preferred
to be set at 0.2 mass % to 2.0 mass %. When the copolymerization
ratio of the sulfonic acid group containing-vinyl monomer is 0.2
mass % or greater, excellent dyeability is expected to be achieved,
and when the ratio is 2.0 mass % or lower, an increase in cost is
suppressed.
[0037] Examples of vinyl monomers copolymerizable with
acrylonitrile are methyl acrylate, methyl methacrylate, esters of
(meth)acrylic acids, vinyl acetate, styrene, acrylamide,
2-hydroxyethyl methacrylate, glycidyl methacrylate and the like.
Preferred examples of sulfonic acid group-containing vinyl monomers
are allyl sulfonic acid, methallylsulfonic acid, styrene sulfonic
acid, vinylsulfonic acid, isoprene sulfonic acid,
2-acrylamide-2-methylpropanesulfonic acid, their metal salts and
amine salts, and so on. However, those listed above are not the
only option to be used in the embodiments of the present invention.
To prepare acrylonitrile-based copolymers, suspension
polymerization carried out in an aqueous medium is preferred.
<Single Fiber Fineness of Acrylic Fiber>
[0038] The single fiber fineness of acrylic fiber related to the
present invention is preferred to be set at 0.5 dtex to 3.5 dtex.
Generally, the finer the fiber is, the lower the color sharpness is
when dyed. However, the acrylic fiber related to the present
invention exhibits color sharpness even though its fineness is 1.2
dtex or lower. A single fiber fineness of 0.5 dtex or higher
contributes to achieving the effects of color sharpness, while a
single fiber fineness of 3.5 dtex or lower makes it easier to
obtain a soft texture when the fiber is formed into a knitted
fabric. Considering those viewpoints, the single fiber fineness is
more preferred to be 0.7 dtex to 2.0 dtex, even more preferably 0.8
dtex to 1.2 dtex.
<Product (K)>
[0039] The acrylic fiber related to the present invention is
preferred to have a product (K) of 10 to 30 obtained by multiplying
the value of knot strength (cN/dtex) and the value of knot
elongation (%). The value of product (K) is used as an index of
pilling resistance by people skilled in the art.
[0040] When the product (K) is 10 or greater, fly waste caused by
finely broken single fibers is less likely to occur during a
spinning process. When the product (K) is 30 or lower, excellent
pilling resistance is achieved.
[0041] From the above viewpoints, the product (K) is more preferred
to be 12 to 25, even more preferably 14 to 20.
<Center-line Mean Roughness (Ra) on Single Fiber Surface>
[0042] The acrylic fiber related to the present invention has fewer
recesses on the surface, resulting in excellent gloss. The
center-line mean roughness (Ra) on a single fiber surface is 3 nm
to 12 nm. An (Ra) of 3 nm or greater is preferred since the fiber
is unlikely to slip because of the friction generated between the
roll and the fiber during spinning. An (Ra) of 12 nm or less is
preferred since it is easier to express gloss. From such
viewpoints, the (Ra) is more preferred to be 4 nm to 10 nm, even
more preferably 5 nm to 9 nm.
<Maximum Height (Ry) of the Profile, 30-point Mean Roughness
(Rz), Distance (S) between Peaks of Convex Portions>
[0043] Regarding the surface of a single acrylic fiber related to
the present invention, it is preferred that a maximum height (Ry)
of the profile be set at 40 nm to 150 nm, a 30-point mean roughness
(Rz) at 20 nm to 80 nm, and a distance (S) between peaks of convex
portions at 800 nm to 1100 nm.
[0044] An (Ry) of 40 nm or greater is preferred since friction is
generated between fibers to improve processability in a spinning
process, while an (Ry) of 150 nm or less is preferred since regular
reflection is expected to occur. From such viewpoints, the (Ry) is
more preferred to be 50 nm to 100 nm, even more preferably 55 nm to
90 nm.
[0045] An (Rz) of 20 nm or greater is preferred since
processability during spinning is better, and an (Rz) of 80 nm is
preferable since the gloss is enhanced. From such viewpoints, the
(Rz) is more preferred to be 30 nm to 65 nm, even more preferably
35 nm to 50 nm.
[0046] An (S) of 800 nm or greater is preferred in view of fiber
spinnability, while an (S) of 1100 nm or less is preferred since
irregularities are fewer on a fiber surface and random reflection
is less likely to occur. From such viewpoints, the (S) is more
preferred to be 900 nm to 1000 nm.
<Number of Recesses on Fiber Surface>
[0047] Furthermore, regarding the acrylic fiber related to the
present invention, the number of recesses of 0.1 .mu.m or deeper is
preferred to be 10 or fewer when counted on the cross section of a
single fiber cut in a direction perpendicular to the fiber axis.
When observed in a cross section perpendicular to the fiber axis
using a later-described method, the number of recesses of 0.1 .mu.m
or deeper is preferred to be no greater than 10 on a fiber surface,
since gloss is enhanced. When recesses of 0.1 .mu.m or deeper are
present on a fiber surface, light reflects randomly. Thus, when the
number of recesses of 0.1 .mu.m or deeper is 10 or fewer on the
acrylic fiber surface related to the present invention, gloss is
enhanced since random reflections are less likely to occur, and a
decrease in gloss is suppressed. From such viewpoints, the number
of recesses of 0.1 .mu.m or deeper is more preferred to be 5 or
fewer. To reduce irregularities on a fiber surface, it is effective
to lower the stretch ratio when the coagulated fiber is stretched
by wet heat.
[0048] The tensile strength of a single acrylic fiber related to
the present invention is preferred to be 1.8 cN/dtex or greater,
more preferably 2.0 cN/dtex or greater, considering processability
during a spinning process or the like. The upper limit of the
tensile strength is not particularly specified, and 3.0 cN/dtex is
sufficient.
[0049] The knot strength of a single acrylic fiber related to the
present invention is preferred to be 1.0 cN/dtex to 1.8
cN/dtex.
[0050] When the knot strength is 1.0 cN/dtex or greater, fly waste
is less likely to occur during a spinning process and
processability is excellent. When the knot strength is 1.8 cN/dtex
or less, pilling resistance is improved. From such viewpoints, the
knot strength is more preferred to be 1.2 cN/dtex to 1.6 cN/dtex,
even more preferably 1.4 cN/dtex to 1.5 cN/dtex.
[0051] To enhance pilling resistance, the knot elongation of a
single acrylic fiber related to the present invention is preferred
to be at least 8% but no greater than 20%, more preferably no
greater than 15%.
<Method for Producing Acrylic Fiber>
[0052] The acrylic fiber related to the present invention is
produced by wet spinning or dry wet spinning. Wet spinning is
preferred in terms of productivity and cost performance.
<Composition of Copolymer>
[0053] In the method for producing acrylic fiber related to the
present invention, it is preferred to use an acrylonitrile-based
copolymer that contains 92 mass % to 96.8 mass % of an
acrylonitrile unit, 2 mass % to 6 mass % of a vinyl monomer unit
and 0.2 mass % to 2.0 mass % of a sulfonic acid group
containing-vinyl monomer unit.
[0054] A spinning dope is formed by dissolving the
acrylonitrile-based copolymer in an organic solvent.
[0055] The spinning dope is preferred to contain 15 mass % to 30
mass % of the acrylonitrile-based copolymer and 70 mass % to 85
mass % of an organic solvent. The acrylonitrile-based copolymer is
preferred to have a concentration of 15 mass % to 30 mass % in the
spinning dope. Such a concentration is preferred to achieve
excellent spinnability, since yarn breakage is less likely to occur
and productivity is high. The copolymer concentration is more
preferred to be 18% to 25% in view of spinnability.
[0056] The solvent is required to be an organic solvent, for
example, dimethylacetamide, dimethylformamide, dimethyl sulfoxide
and the like. Among them, dimethylacetamide is preferred from the
viewpoint of productivity in fiber manufacturing and balancing the
color sharpness and anti-pilling properties of the obtained
pilling-resistant acrylic fiber.
[0057] A temperature of 40.degree. C. or higher is preferred for
dissolving the acrylonitrile-based copolymer in an organic solvent,
since fewer undissolved components will remain, thus prolonging the
life span of a filter medium in a filtration system such as a
filter press while preventing a decrease in thread-forming
properties. On the other hand, a dissolving temperature of
95.degree. C. or lower is preferred since the copolymer is less
likely to undergo color change.
[0058] The temperature of the spinning dope after the
acrylonitrile-based copolymer is dissolved in an organic solvent is
preferred to be 40.degree. C. to 95.degree. C. If the temperature
is set at 40.degree. C. to 95.degree. C., an increase in nozzle
pressure due to low viscosity, gelation of the spinning dope or the
like is prevented, thus optimizing thread-forming properties and
spinnability.
<Temperature of Coagulation Bath>
[0059] Next, a coagulated fiber bundle is formed by discharging the
spinning dope through multiple discharge ports of a spinning nozzle
into a coagulation bath set to have a solvent concentration of 40
mass % to 60 mass % and a temperature of 35.degree. C. to
50.degree. C.
[0060] When the solvent concentration and temperature are set in
the above ranges, coagulation at an undesired faster speed is
prevented and recessed wrinkles are less likely to be formed on a
fiber surface.
<Jet-Stretch Ratio, Hot-water Stretch Ratio, Dry-heat Stretch
Ratio, Multiplication Product of Stretch Ratios>
[0061] The jet-stretch ratio is preferred to be 0.4 to 2.2 when the
spinning dope is discharged through spinning nozzle ports. The
jet-stretch ratio is obtained when the draw velocity of coagulated
fiber is divided by the extrusion velocity.
[0062] A jet-stretch ratio of 0.4 to 2.2 is preferred since fiber
breakage is less likely to occur in the spinning bath and
spinnability is thereby excellent. From such viewpoints, the
jet-stretch ratio is more preferred to be 0.6 to 2.0.
[0063] Moreover, the coagulated fiber bundle is stretched in hot
water to have a stretch ratio of 2 to 4 times, and an oil agent is
applied and dried on the fiber bundle. Then, the fiber bundle is
stretched by applying dry heat to have a stretch ratio of 1.2 to 3
times. During those procedures, the value of a product (S),
obtained by multiplying the hot-water stretch ratio and the
dry-heat stretch ratio, is set to be 4 to 6.
[0064] A dry-heat stretch ratio of at least 1.2 times is preferred,
since recesses on a fiber surface are elongated to increase the
area of smooth surface, thus enhancing the gloss of the fiber. A
dry-heat stretch ratio of no greater than 3 times is preferred,
since pilling resistance is improved and fiber breakage is reduced
during a spinning process.
[0065] To reduce recesses on a fiber surface and to enhance gloss,
the dry-heat stretch ratio is more preferred to be at least 1.5
times, even more preferably at least 1.7 times. To improve
processability, the stretch ratio is preferred to be no greater
than 2 times.
[0066] In addition, the product (S) is preferred to be 4 to 6,
since processability during spinning is excellent, and appropriate
fiber strength is achieved. Also, pilling resistance is expected to
be excellent. The product (S) is more preferred to be 4.5 to
5.5.
<Temperature of Hot Water, Fiber Temperature for Dry-heat
Stretching>
[0067] When the fiber is stretched in hot water, the water
temperature is preferred to be 80.degree. C. to 98.degree. C. In
such a temperature range, fiber breakage is less likely to occur
during hot-water stretching.
[0068] In addition, the fiber temperature at the time for
stretching by dry heat is preferred to be 150.degree. C. to
170.degree. C. A temperature of at least 150.degree. C. makes it
easier to stretch wrinkles on the fiber surface, and a temperature
of no higher than 170.degree. C. reduces color change caused by
heat while decreasing fiber breakage during dry-heat
stretching.
[0069] Applying heat on a fiber bundle for dry-heat stretching may
be conducted by using a hot roll, contact heating on a hot plate,
or non-contact heating by hot air. Among them, hot roll heating is
preferred because heat is efficiently applied on a fiber
bundle.
[0070] By using a hot roll to apply heat on a fiber bundle, the
fiber temperature is appropriately increased by adjusting the
temperature of the hot roll and the time for the fiber bundle to be
in contact with the hot roll. It is preferred to use multiple hot
rolls so that both surfaces of the fiber bundle are heated.
[0071] The temperature of a hot roll is preferred to be 150.degree.
C. to 190.degree. C. A temperature of 190.degree. C. or lower
suppresses the color change of the fiber caused by heat.
[0072] Then, the dry-heat stretched fiber bundle is crimped and
stored in a container.
[0073] The swelling degree of fiber that is stretched in hot water
is preferred to be set at 80% to 130% A swelling degree of 80% to
130% is preferred since dryness and productivity of the fiber are
excellent. In addition, fewer wrinkles are expected to appear on
the fiber surface.
<Thermal Relaxation>
[0074] Lastly, thermal relaxation is conducted on the fiber to have
a thermal shrinkage rate of 5% to 20% to obtain the final product
of acrylic fiber. Conditions for thermal relaxation are determined
based on the thermal shrinkage rate of fiber. A fiber thermal
shrinkage rate of 5% to 20% is preferred since knot strength and
knot elongation are set to have a value that is sufficient for
exhibiting pilling resistance.
[0075] The thermal shrinkage rate means the rate of fiber shrinkage
determined when the fiber is compared before and after thermal
relaxation treatment.
[0076] The temperature for thermal relaxation is set at 120.degree.
C. to 135.degree. C. A temperature of 120.degree. C. or higher is
preferred since the strength and elongation of a single fiber are
set to achieve excellent carding processability during spinning,
and a temperature of 135.degree. C. or lower makes it easier to
obtain excellent pilling-resistant single fibers.
[0077] An acrylic fiber bundle produced by the above-described
method is cut into short fibers. The acrylic fiber was cut by a
cutter to form short fibers and then spun. Spun yarn may be formed
with 100% of acrylic fiber related to the present invention, or may
be formed by blending other fibers, for example, synthetic or
chemical fibers such as generic acrylic fibers, polyester fibers,
nylon fibers and rayon fibers and/or natural fibers such as cotton,
wool and silk.
<Fiber Content of Spun Yarn>
[0078] The spun yarn related to the present invention is preferred
to contain the aforementioned acrylic fiber at 40 mass % or
greater. A content of 40 mass % or greater contributes to
expressing gloss and pilling resistance characterized in the
acrylic fiber related to the present invention. From such
viewpoints, the content is more preferred to be 60 mass % or
greater, even more preferably 80 mass % or greater.
<Yarn Count of Spun Yarn>
[0079] The yarn count of the spun yarn related to the present
invention is preferred to be a cotton count of 40 to 70. A cotton
count of 40 or higher makes it easier to form soft fabrics based on
the effects derived from a smaller fiber fineness of the acrylic
fiber related to the present invention. In addition, a cotton count
of 70 or lower makes it easier to provide the strength required for
the spun yarn during its use.
[0080] The coefficient of variation (CV) of yarn unevenness in the
spun yarn is preferred to be 11.5% or lower. When a CV is 11.5% or
lower, a knitted fabric has good appearance with enhanced gloss.
The CV is more preferred to be 11% or lower, even more preferably
10% or lower.
<Blending Ratio of Cellulose Fiber>
[0081] The spun yarn related to the present invention is preferred
to contain a cellulose fiber at 10 mass % to 40 mass %. A content
of cellulose fiber at 10 mass % or greater enhances
moisture-absorption and heat-generation properties of the spun
yarn. A content of 40 mass % or lower improves the pilling
resistance and heat retention rate.
<Yarn Content of Knitted Fabric>
[0082] The knitted fabric related to the present invention is
preferred to contain the spun yarn at 40 mass % or greater. A
content of 40 mass % or greater contributes to achieving the
effects of enhancing the gloss and pilling resistance of the
knitted fabric. From such viewpoints, the content is more preferred
to be 50 mass % or greater, even more preferably 60 mass % or
greater.
<Basis Weight of Knitted Fabric>
[0083] The knitted fabric related to the present invention is
preferred to have a basis weight of 150 g/m.sup.2 to 230 g/m.sup.2.
A basis weight of 150 g/m.sup.2 or greater increases the strength,
and the knitted fabric is less likely to be torn. A basis weight of
230 g/m.sup.2 or less contributes to obtaining a lightweight, soft,
knitted fabric suitable for undergarments.
<Pilling Resistance>
[0084] The knitted fabric related to the present invention is
preferred to exhibit a pilling resistance rated at 4 or higher. A
pilling resistance rated at 4 or higher reduces the amount of
pilling so as to give the fabric a clean appearance. The pilling
resistance rating is more preferred to be 4.5 or higher.
<Heat Retention>
[0085] The knitted fabric related to the present invention is
preferred to have a heat retention rate of 15% to 50%. When the
knitted fabric is made into undergarments, a heat retention rate of
15% or higher provides warmth, and a heat retention rate of 50% or
lower prevents excessive warmth.
EXAMPLES
[0086] The acrylic fiber related to the present invention is
described by referring to the examples below.
(Method for Measuring Irregularities on Fiber Surface)
[0087] The depths of irregularities on the surface of an acrylic
fiber related to the present invention are determined by the
center-line mean roughness (Ra), maximum height (Ry) of the
profile, 30-point mean roughness (Rz), and distance (S) between
peaks, which are described below. They are measured by using a
laser microscope.
[0088] FIGS. 1.about.4 are schematic views, each showing the
surface of a single acrylic fiber related to the present invention
observed in a cross section perpendicular to a fiber longitudinal
direction.
(Center-Line Mean Roughness <Ra> on Single Fiber Surface)
[0089] As shown in FIG. 1, the center-line mean roughness (Ra) on
the surface of a single fiber is the value expressed in nanometers
(nm), which is determined in base length (L) taken out of the
roughness curve to be parallel to the center line (m) when the
distances from the center line (m) to the roughness-curve line are
measured and the absolute deviation values are totaled to obtain
the mean absolute deviation.
(Maximum Height <Ry> of the Profile of Single Fiber
Surface)
[0090] As shown in FIG. 2, the maximum height (Ry) of the profile
of a single fiber surface is the value expressed in nanometers
(nm), which is determined in base length (L) taken out of the
roughness curve to be parallel to the center line (m) when the
distance (Rp) from the highest peak line to the center line (m) and
the distance (Rv) from the lowest valley line to the center line
(m) are measured and the sum (Rp+Rv) is obtained.
(30-Point Mean Roughness <Rz> on Single Fiber Surface)
[0091] As shown in FIG. 3, the 30-point mean roughness (Rz) on the
surface of a single fiber is the value expressed in nanometers
(nm), which is determined in the base length taken out of the
roughness curve to be parallel to the center line when the mean
absolute value of elevations (Yp) from the highest peak to the 15th
highest peak and the mean absolute value of elevations (Yv) from
the lowest valley to the 15th lowest valley, both measured in a
vertical direction of the profile, and the sum (Yp+Yv) is
obtained.
(Distance <S> between Peaks on Single Fiber Surface)
[0092] As shown in FIG. 4, the distance (S) between peaks on the
surface of a single fiber is the value expressed in nanometers
(nm), which is determined in base length (L) taken out of the
roughness curve to be parallel to the center line when the lengths
corresponding to the distances between adjacent peaks are measured
and the mean distance value of multiple lengths between peaks of
the convex portions is obtained.
(Tensile Strength and Elongation, Knot Strength and Knot
Elongation)
[0093] Measurement was conducted in accordance with JIS L1015.
(Number of Recesses of 0.1 .mu.m or Deeper on Single Fiber
Surface)
[0094] After hot air was applied from a dryer on 200 to 300 acrylic
fibers related to the present invention to stretch the shrunk
fibers, the fibers were put into a tube. The tube was made of
polyethylene that shrinks only in a circumferential direction.
[0095] Next, the polyethylene tube filled with the acrylic fibers
related to the present invention was cut into approximately 2 mm
lengths using a new razor blade in an approximate perpendicular
direction to the axis.
[0096] One of the cut surfaces was fixed on a stage using a
double-sided tape, and gold was deposited on the other cut surface
set for observation using a low-temperature ion sputtering
apparatus (JFC1100, made by JEOL Ltd.) under conditions of 1200 V
and 5 mA for 8 minutes. Accordingly, an observation sample of
acrylic fibers related to the present invention was prepared.
[0097] Using a scanning electron microscope (model number XL-20,
made by Philips Electronics Company), a fiber cross section of the
sample was captured at a magnification of 5000 times. The depth of
a recess was determined as the length of a line, which starts at
the tangent line connecting convex portions on both sides of the
recess and is drawn vertically down to the deepest spot of the
recess. Then, the number of recesses of 0.1 .mu.m or deeper was
counted on the fiber surface. The same procedure was conducted on
three samples, and the average value was set as the number of
recesses of 0.1 .mu.m or deeper present on a fiber cross
section.
(Evaluation of Gloss)
[0098] The gloss was evaluated as follows.
[0099] Acrylic fibers of Examples 1 and 2 and Comparative Example 1
were used 100% to form spun yarns respectively under the same
conditions, which were then formed into fabrics under the same
conditions. The gloss of each fabric was visually evaluated.
[0100] .smallcircle.: excellent gloss
[0101] .times.: poor gloss
Example 1
[0102] An acrylonitrile-based copolymer with a reduced viscosity of
1.8 containing 95% of acrylonitrile, 4.4% of vinyl acetate and 0.6%
of sodium methallylsulfonate was dissolved in dimethylacetamide.
Accordingly, a spinning dope was obtained, having a copolymer
concentration of 24% and a viscosity at 50.degree. C. of 200
poise.
[0103] The spinning dope was discharged in a 41.degree. C.
coagulation bath with a dimethylacetamide concentration of 56%
through multiple discharge ports with a port diameter of 0.045 mm.
Then, the obtained fiber was stretched to be 2.5 times in
98.degree. C. hot water while the solvent was washed out. An oil
agent was applied on the fibers and dried using multiple hot
rollers set to have a surface temperature of 150.degree. C. The
fibers were further heated to 160.degree. C. by applying heat using
a 180.degree. C. hot roller. The fibers were stretched in air to be
twice as long, crimped and put into a container.
[0104] Furthermore, thermal relaxation treatment was conducted on
the fiber bundle to have a thermal shrinkage rate of 7% to 9%.
Accordingly, acrylic fiber with a single fiber fineness of 1.0 dtex
was prepared. Conditions are specified in Table 1 and results are
shown in Table 2.
[0105] The product (K), obtained by multiplying knot strength
(cN/dtex) and knot elongation (%) was 15.9, sufficient for
exhibiting excellent pilling resistance. The number of recesses of
0.1 .mu.m or deeper was two, and excellent gloss was obtained
relative to comparative examples.
Example 2
[0106] The same spinning process as in Example 1 was conducted
except that the wet-heat stretch ratio and the dry-heat stretch
ratio were changed. The conditions are specified in Table 1 and
results are shown in Table 2.
[0107] Accordingly, the product (K) obtained by multiplying knot
strength (cN/dtex) and knot elongation (%) was 16.6, sufficient for
exhibiting excellent pilling resistance. The number of recesses of
0.1 .mu.m or deeper was four, and excellent gloss was obtained
relative to comparative examples.
Examples 3.about.11
[0108] Acrylic fibers were prepared by conducting the same process
as in Example 1 except that conditions for forming acrylic fibers
were changed as respectively specified in Table 1. Physical
properties of each acrylic fiber are shown in Table 1.
Comparative Example 1
[0109] Acrylic fiber was prepared the same as in Example 1 except
that no dry-heat stretching was conducted but the hot-water stretch
ratio was increased to set the overall stretch ratio to be the
same. The conditions are specified in Table 1 and results are shown
in Table 2.
[0110] Accordingly, the product (K) obtained by multiplying knot
strength (cN/dtex) and knot elongation (%) was 25.7, at which
pilling resistance was exhibited, but the rating was not so high as
that in the acrylic fiber related to the present invention. In
addition, the number recesses of 0.1 .mu.m or deeper was 15, and
gloss was poor.
Comparative Example 2
[0111] Acrylic fiber was prepared the same as in Example 3 except
that no dry-heat stretching was conducted but the hot-water stretch
ratio was increased to set the overall stretch ratio to be the
same. The conditions are specified in Table 1 and results are shown
in Table 2.
[0112] Accordingly, the product (K) obtained by multiplying knot
strength (cN/dtex) and knot elongation (%) was 20, at which pilling
resistance was exhibited, but the rating was not so high as that in
the acrylic fiber related to the present invention. In addition,
gloss was poor.
Comparative Example 3
[0113] Acrylic fiber was prepared by the conditions described in
JP2013-209771A for producing a carbon-fiber-precursor acrylic
fiber. The conditions are specified in Table 1 and results are
shown in Table 2.
[0114] The carbon-fiber-precursor acrylic fiber had a low value of
product (K) obtained by multiplying knot strength and knot
elongation. During the spinning process the fiber broke, indicating
that the physical properties of the acrylic fiber were so low that
the fiber could not be spun.
Comparative Example 4
[0115] According to the conditions described in JP H11-222716A for
producing glossy fibers, acrylic fiber was prepared to have a
single fiber fineness of 22 dtex and a flatness rate of 22. The
conditions are specified in Table 1 and results are shown in Table
2.
[0116] Accordingly, the product (K) was at a value sufficient for
exhibiting pilling resistance, but the fiber fineness level was too
high for achieving soft texture. Thus, the fiber is not suitable
for apparel products.
TABLE-US-00001 TABLE 1 Spinning Coagulation Hot-water Dry-heat
Thermal Single dope Coagulation bath stretch stretch relaxation
fiber Tensile AN/AV/MS temp. bath temp. concentration ratio ratio
temp. fineness strength (mass %) (.degree. C.) (.degree. C.) (mass
%) (times) (times) (.degree. C.) (dtex) (cN/dtex) Example 1
95/4.4/0.6 75 41 56 2.5 2 128 1.0 2.6 Example 2 95/4.4/0.6 75 41 56
3.3 1.5 128 1.0 3 Example 3 95/4.4/0.6 80 45 56 2.25 2 123 0.8 2.69
Example 4 95/4.4/0.6 80 45 56 2.25 2 128 0.8 2.55 Example 5
95/4.4/0.6 80 45 56 2.25 2 132 0.8 2.7 Example 6 95/4.4/0.6 80 45
56 2.65 1.7 123 0.8 2.78 Example 7 95/4.4/0.6 80 45 56 2.65 1.7 128
0.8 2.55 Example 8 95/4.4/0.6 80 45 56 2.65 1.7 132 0.8 2.48
Example 9 95/4.4/0.6 80 35 56 2.25 2 123 0.8 2.42 Example 10
95/4.4/0.6 75 45 56 2.25 2 123 0.8 2.46 Example 11 95/4.4/0.6 80 41
56 3 1.5 132 0.8 3.17 Comp. 95/4.4/0.6 75 41 56 5 -- 128 1.0 2.8
Example 1 Comp. 95/4.4/0.6 80 45 56 4.5 -- 123 0.8 2.77 Example 2
Comp. AN/AAm/MA = 70 38 65 5.4 1.4 -- 1.2 8.00 Example 3
96.5/5.7/0.8 Comp. AN/AV = 93/7 85 30 30 2 2 140 22.0 1.63 Example
4 Center-line 30-point Maximum Distance Number of Knot Knot Product
(K) mean mean height of (S) betw. recesses strength elongation
(knot strength .times. roughness roughness profile peaks of 0.1
.mu.m (cN/dtex) (%) knot elongation) (Ra) (nm) (Rz) (nm) (Ry) (nm)
(nm) or deeper Gloss Example 1 1.42 11.2 15.9 2 .smallcircle.
Example 2 1.44 11.5 16.6 5.7 38 64 940 4 .smallcircle. Example 3
1.69 11.5 19.4 8.4 46 80 988 .smallcircle. Example 4 1.42 12.1 17.2
.smallcircle. Example 5 1.48 13.9 20.6 .smallcircle. Example 6 1.4
13.4 18.8 8.7 57 99 988 .smallcircle. Example 7 1.25 10.6 13.3
.smallcircle. Example 8 1.28 13.7 17.5 .smallcircle. Example 9 1.59
17.3 27.5 9.5 56 98 988 .smallcircle. Example 10 1.51 15.4 23.3 10
63 103 .smallcircle. Example 11 1.62 9.5 15.9 9 50 92 .smallcircle.
Comp. 1.76 16.7 29.4 14.6 105 194 984 15 x Example 1 Comp. 1.35
14.8 20 15.6 93 185 15 x Example 2 Comp. 1.19 1.4 1.7 80 460 720 13
x Example 3 Comp. 1.31 14.1 18.5 6.3 40 70 4 .smallcircle. Example
4
Example 12
[0117] By blending 70 mass % of the acrylic fiber prepared in
Example 1 and 30 mass % of MicroModal (1.0 dtex, made by Lenzing
Corporation), a spun yarn was formed to have a cotton count of 50
and a twist count of 873 t/m. Its physical properties are shown in
Table 2.
Example 13
[0118] Using 100% of the acrylic fiber prepared in Example 1, a
spun yarn was formed to have a cotton count of 60 and a twist count
of 1139 t/m. Its physical properties are shown in Table 2.
Examples 14, 15
[0119] Spun yarns were obtained the same as in Example 13 except
that their cotton counts were changed respectively as specified in
Table 2. Their physical properties are shown in Table 2.
Example 16
[0120] A spun yarn was formed by using 100 mass % of the acrylic
fiber prepared in Example 11. The cotton count was 40 and the twist
count 820 t/m. Their physical properties are shown in Table 2.
Comparative Example 5
[0121] By blending 70 mass % of the acrylic fiber prepared in
Comparative Example 1 and 30 mass % of MicroModal (1.0 dtex, made
by Lenzing Corporation), a spun yarn was formed to have a cotton
count of 50 and a twist count of 900 t/m. Its physical properties
are shown in Table 2.
[0122] When compared with the fiber in Example 12, the variations
in yarn unevenness were greater.
[0123] When spun yarns prepared in Example 12 and Comparative
Example 5, each wound on a cone, were visually compared, it was
verified that the spun yarn of Example 12 had better gloss.
[0124] Using 100 mass % of the acrylic fiber prepared in
Comparative Example 1, a spun yarn was formed to have a cotton
count of 60 and a twist count of 1139 t/m. Its physical properties
are shown in Table 2.
[0125] Variations in yarn unevenness were greater than those in the
spun yarn of Example 13.
Comparative Examples 7, 8
[0126] A spun yarn was formed the same as in Comparative Example 6
except that the cotton count was changed as specified in Table 2.
Its physical properties are shown in Table 2.
Comparative Example 9
[0127] Using 100 mass % of the acrylic fiber of Comparative Example
2, a spun yarn was formed to have a cotton count of 40 and a twist
count of 820 t/m. Its physical properties are shown in Table 2.
[0128] When spun yarns prepared in Examples 13.about.16 and
Comparative Examples 6.about.9, each wound on a cone, were visually
compared, it was verified that spun yarns of the examples had
better gloss than those of the comparative examples.
Example 17
[0129] Using the spun yarn of Example 15, a jersey weft-knit fabric
was prepared by setting the gauge at 14G. The basis weight was 210
g/m.sup.2, the anti-pilling rating was 4.5, and the heat retention
rate was 45.1%.
Comparative Example 10
[0130] Using the spun yarn of Comparative Example 8, a jersey
weft-knit fabric was prepared by setting the gauge at 14G. The
basis weight was 210 g/m.sup.2, the anti-pilling rating was 4.5,
and the heat retention rate was 44.9%.
[0131] However, the gloss was not as good as that of Example
17.
TABLE-US-00002 TABLE 2 Twist Strength of CV of CV of yarn Blend
ratio Cotton count single yarn strength Elongation unevenness Yarn
structure (mass %) count (t/m) (g) (%) (%) (%) Example 12 acrylic
fiber of 70 50 873 7.01 12.98 9.56 Examp. 1 MicroModal 30 Example
13 acrylic fiber of Examp. 1 100 60 1139 9.49 14.37 12.22 Example
14 acrylic fiber of Examp. 1 100 50 1038 8.73 15.4 11.16 Example 15
acrylic fiber of Examp. 1 100 40 921 9.72 16.76 9.82 Example 16
acrylic fiber of Examp. 11 100 40 820 210.6 11.1 16.8 11.7 Comp.
acrylic fiber of Comp. 70 40 921 14.6 14.3 Example 5 Examp. 1
MicroModal 30 Comp. acrylic fiber of Comp. 100 60 1100 118 9 13
14.3 Example 6 Examp. 1 Comp. acrylic fiber of Comp 100 50 1000 178
11.3 14 14 Example 7 Examp 1 Comp. acrylic fiber of Comp. 100 40
890 229 10.1 16 13.8 Example 8 Examp. 1 Comp. acrylic fiber of
Comp. 100 40 820 227.2 10.1 16.9 11.9 Example 9 Examp. 2
TABLE-US-00003 TABLE 3 Basis Pilling Heat weight resistance
retention rate Spun yarn (g/m.sup.2) (rating) (%) Example 17
Example 15 210 4.5 45.1 Comp. Comp. 210 4.5 44.9 Example 10 Example
8
* * * * *