U.S. patent application number 16/474419 was filed with the patent office on 2019-11-14 for lyocell fiber, nonwoven fibrous aggregate containing the same, and a mask pack sheet containing the same.
This patent application is currently assigned to KOLON INDUSTRIES, INC.. The applicant listed for this patent is KOLON INDUSTRIES, INC.. Invention is credited to Sang Woo JIN, Jong Chul JUNG, Woo Chul KIM, Sang Mok LEE, Sang Yeol LEE.
Application Number | 20190345641 16/474419 |
Document ID | / |
Family ID | 62709746 |
Filed Date | 2019-11-14 |
United States Patent
Application |
20190345641 |
Kind Code |
A1 |
JUNG; Jong Chul ; et
al. |
November 14, 2019 |
LYOCELL FIBER, NONWOVEN FIBROUS AGGREGATE CONTAINING THE SAME, AND
A MASK PACK SHEET CONTAINING THE SAME
Abstract
Disclosed are a lyocell fiber, a nonwoven fibrous aggregate
containing the lyocell fiber, and a mask pack sheet containing the
nonwoven fibrous aggregate. The lyocell fiber contains a
monofilament having a cross-section of a flat yarn or a flat yarn
having a curvature. Such lyocell fiber exhibits physical properties
that could not be provided by existing lyocell fibers having a
circular cross-section, and thus can afford excellent properties
such as excellent bendability for industrial material application,
good feel and soft gloss property for clothes or interior
applications, and transparency, skin adhesion, absorption, and
maintenance of a solvent such as moisture, and a smooth surface
feel for a mask pack nonwoven fibrous aggregate application.
Inventors: |
JUNG; Jong Chul; (Seoul,
KR) ; KIM; Woo Chul; (Seoul, KR) ; JIN; Sang
Woo; (Seoul, KR) ; LEE; Sang Yeol; (Seoul,
KR) ; LEE; Sang Mok; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KOLON INDUSTRIES, INC. |
Seoul |
|
KR |
|
|
Assignee: |
KOLON INDUSTRIES, INC.
Seoul
KR
|
Family ID: |
62709746 |
Appl. No.: |
16/474419 |
Filed: |
December 29, 2017 |
PCT Filed: |
December 29, 2017 |
PCT NO: |
PCT/KR2017/015775 |
371 Date: |
June 27, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D01F 2/02 20130101; D04H
1/425 20130101; D01D 1/02 20130101; D01F 2/00 20130101 |
International
Class: |
D01F 2/02 20060101
D01F002/02; D04H 1/425 20060101 D04H001/425 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 29, 2016 |
KR |
10-2016-0182500 |
Claims
1. A lyocell fiber comprising lyocell multifilaments prepared by
spinning a lyocell spinning dope comprising a cellulose pulp and a
solvent, wherein a monofilament making up the multifilament has a
cross-section having a central major axis (L1) and a central minor
axis (S1), a ratio of lengths of the central major axis (L1) and
the central minor axis (S1) is 1.5:1.about.10.5:1, and a ratio of a
length of a central major axis (L1) and a length of a straight line
(L2) between both ends of the central major axis is 1.0-1.5:1.
2. The lyocell fiber according to claim 1, wherein the length of
the central major axis (L1) is 12.about.42 .mu.m, and the length of
the central minor axis (S1) is 4-7 .mu.m.
3. The lyocell fiber according to claim 1, wherein the monofilament
has fineness of 1.0-4.0 denier, and a value obtained by dividing a
cross-sectional perimeter of the monofilament by fineness is 24.5
to 32 .mu.m/denier.
4. A nonwoven fibrous aggregate containing lyocell fiber, wherein a
monofilament making up a lyocell fiber has a cross-section having a
central major axis (L1) and a central minor axis (S1), a ratio of
lengths of the central major axis (L1) and the central minor axis
(S1) is 1.5:1.about.10.5:1, and a ratio of a length of the central
major axis (L1) and the length of a straight line (L2) between both
ends of the central major axis is 1.0-1.5:1.
5. The nonwoven fibrous aggregate according to claim 4, wherein the
length of the central major axis (L1) of the monofilament is 12-42
.mu.m, and the length of the central minor axis (S1) is 4-7
.mu.m.
6. The nonwoven fibrous aggregate according to claim 4, wherein the
monofilament has fineness of 1.0-4.0 denier, and a value obtained
by dividing the cross-sectional perimeter of the monofilament by
the fineness is 24.5 to 32 .mu.m/denier.
7. The nonwoven fibrous aggregate according to claim 4, wherein the
fineness of the lyocell fiber is 1.0 to 4.0 denier.
8. The nonwoven fibrous aggregate according to claim 4, wherein the
fiber length of the lyocell fiber is 36 to 40 mm.
9. The nonwoven fibrous aggregate according to claim 4, wherein a
crimp number of the lyocell fiber is 8 to 12 cpi.
10. The nonwoven fibrous aggregate according to claim 4, wherein
the lyocell fiber has an emulsion content of 0.1 to 0.4 wt %, based
on 100 wt % of the lyocell fiber.
11. The nonwoven fibrous aggregate according to claim 4, wherein a
basis weight of the nonwoven fibrous aggregate is 30 to 60
g/m.sup.2.
12. The nonwoven fibrous aggregate according to claim 4, wherein
the thickness of the nonwoven fibrous aggregate is 0.3 to 0.5
mm.
13. The nonwoven fibrous aggregate according to claim 4, wherein
the nonwoven fibrous aggregate has moisture absorption of 1000 to
1600%, based on the weight of the lyocell fiber.
14. The nonwoven fibrous aggregate according to claim 4, wherein
the nonwoven fibrous aggregate has transparency after moisture
treatment of 80 to 84%.
15. The nonwoven fibrous aggregate according to claim 4, wherein
the nonwoven fibrous aggregate has transparency after essence
treatment of 88 to 94%.
16. The nonwoven fibrous aggregate according to claim 4, wherein
the nonwoven fibrous aggregate has skin adhesion after moisture
treatment of 3.6 to 4.2 gf.
17. The nonwoven fibrous aggregate according to claim 4, wherein
the nonwoven fibrous aggregate has skin adhesion after essence
treatment of 4.5 to 5.3 gf.
18. The nonwoven fibrous aggregate according to claim 4, wherein
the nonwoven fibrous aggregate has an emulsion content of 0.001 wt
% or less, based on 100 wt % of the nonwoven fibrous aggregate.
19. A mask pack sheet using the nonwoven fibrous aggregate
according to claim 4.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to lyocell fiber, a nonwoven
fibrous aggregate containing the same, and a mask pack sheet
containing the same.
BACKGROUND OF THE INVENTION
[0002] A fiber is a natural or synthetic object that is flexible
and thin, and has large length to thickness ratio, in view of the
shape. Such fiber is divided into filament fiber, medium length
fiber, and staple fiber according to the shape, and is divided into
natural fiber and man-made fiber according to the raw material.
[0003] From the past, fibers have had a close relationship to human
life, and natural fibers such as cotton, linen, wool, and silk have
been used as main materials for clothes. With the development of
science and technology after the industrial revolution, the use of
fibers was expanded to industrial applications in addition to
clothing applications, and in order to fulfill a rapidly increasing
demand for fibers according to the development of culture and an
increase in population, the field of man-made fibers was developed
for novel fiber materials.
[0004] Among the manmade fibers, regenerated fibers not only have
excellent feel and wearability, but also have much quicker moisture
absorption and discharge capacity than cotton, and thus have been
frequently used as raw materials for clothes. Particularly, among
the regenerated fibers, rayon fiber has excellent gloss and color
formation properties, can realize feel equivalent to natural fiber,
and is recognized as a material that is harmless to a human body,
and thus was broadly used in the past. However, such rayon fiber is
easily shrunken and wrinkled, the preparation process is
complicated, and many chemicals are used in the process of
dissolving wood pulp, and the like, thus causing environmental
problems during the operation and environmental pollution during
the processes of waste water treatment, and the like.
[0005] Thus, studies on fibers that are harmless to the environment
and the human body and having much better properties than the
existing fiber have progressed, and recently, lyocell fibers
prepared from natural pulp and an amine oxide hydrate were
introduced. Such lyocell fiber has excellent fiber properties such
as tensile property and feel compared to the existing regenerated
fiber, but does not generate pollutants during the production
process, and an amine oxide solvent that is used can be recycled
and be biodegraded during discardment, and thus it is being used in
various fields as an environmentally friendly fiber.
[0006] However, currently, only the lyocell fiber having a circular
cross-sectional shape can be produced, but it is expected that
various properties may be exhibited according to the
cross-sectional shape of lyocell fiber. Therefore, there is a
demand for studies on the preparation technology of lyocell fiber
having various cross-sectional shapes.
SUMMARY OF THE INVENTION
Technical Problem
[0007] The present invention provides a lyocell fiber wherein a
monofilament has a cross-section of a flat yarn or a flat yarn
having a curvature, and thereby, can afford excellent properties
such as excellent bendability for industrial material applications,
good feel and soft gloss properties for clothes or interior
applications, and transparency, skin adhesion, absorption, and
maintenance of a solvent such as moisture, and smooth surface feel
for a mask pack nonwoven fibrous aggregate application.
Technical Solution
[0008] According to a preferable embodiment of the present
invention, a lyocell fiber including a lyocell multifilament
prepared by spinning a lyocell spinning dope including cellulose
pulp and a solvent is provided, wherein a monofilament making up
the multifilament has a cross-section having a central major axis
(L1) and a central minor axis (S1), a ratio of lengths of the
central major axis (L1) and the central minor axis (S1) is
1.5:1.about.10.5:1, and a ratio of the length of the central major
axis (L1) and a length of a straight line (L2) between both ends of
the central major axis is 1.0.about.1.5:1.
[0009] In the above embodiment, the length of the central major
axis (L1) may be 12.about.42 .mu.m, and the length of the central
minor axis (S1) may be 4.about.7 .mu.m.
[0010] In the above embodiment, the monofilament may have fineness
of 1.0.about.4.0 denier, and a value obtained by dividing the
cross-sectional perimeter of the monofilament by the fineness may
be 22 .mu.m/denier or more.
[0011] According to another preferable embodiment of the present
invention, a nonwoven fibrous aggregate containing a lyocell fiber
is provided, wherein a monofilament making up the lyocell fiber has
a cross-section having a central major axis (L1) and a central
minor axis (S1), a ratio of lengths of the central major axis (L1)
and the central minor axis (S1) is 1.5:1.about.10.5:1, and a ratio
of a length of the central major axis (L1) and a length of a
straight line (L2) between both ends of the central major axis is
1.0.about.1.5:1.
[0012] In the above embodiment, the length of the central major
axis (L1) of the monofilament may be 12.about.42 .mu.m, and the
length of the central minor axis (S1) may be 4.about.7 .mu.m.
[0013] In the above embodiment, the monofilament may have fineness
of 1.0.about.4.0 denier, and a value obtained by dividing the
cross-sectional perimeter of the monofilament by the fineness may
be 24.5 to 32 .mu.m/denier.
[0014] In the above embodiment, the fineness of the lyocell fiber
may be 1.0 to 4.0 denier.
[0015] In the above embodiment, the fiber length of the lyocell
fiber may be 36 to 40 mm.
[0016] In the above embodiment, a crimp number of the lyocell fiber
may be 8 to 12 cpi.
[0017] In the above embodiment, the lyocell fiber may have an
emulsion content of 0.1 to 0.4 wt %, based on 100 wt % of the
lyocell fiber.
[0018] In the above embodiment, a basis weight of the nonwoven
fibrous aggregate may be 30 to 60 g/m.sup.2.
[0019] In the above embodiment, the thickness of the nonwoven
fibrous aggregate may be 0.3 to 0.5 mm.
[0020] In the above embodiment, the nonwoven fibrous aggregate may
have moisture absorption of 1000 to 1600%, based on the weight of
the lyocell fiber.
[0021] In the above embodiment, the nonwoven fibrous aggregate may
have transparency after moisture treatment of 80 to 84%.
[0022] In the above embodiment, the nonwoven fibrous aggregate may
have transparency after essence treatment of 88 to 94%.
[0023] In the above embodiment, the nonwoven fibrous aggregate may
have skin adhesion after moisture treatment of 3.6 to 4.2 gf.
[0024] In the above embodiment, the nonwoven fibrous aggregate may
have skin adhesion after essence treatment of 4.5 to 5.3 gf.
[0025] In the above embodiment, the nonwoven fibrous aggregate may
have an emulsion content of 0.001 wt % or less, based on 100 wt %
of the nonwoven fibrous aggregate.
[0026] According to yet another embodiment of the present
invention, a mask pack sheet using the above-explained nonwoven
fibrous aggregate is provided.
Advantageous Effects
[0027] The present invention provides a lyocell fiber wherein a
monofilament has a cross-section of a flat yarn or a flat yarn
having a curvature, a nonwoven fibrous aggregate containing the
same, and a mask pack sheet including the same, thereby exhibiting
physical properties that could not be provided in the existing
lyocell fiber having a circular cross-section, and thus, can afford
excellent properties such as excellent bendability for industrial
material application, good feel and soft gloss properties for
clothes or interior applications, and transparency, skin adhesion,
absorption and maintenance of a solvent such as moisture, and
smooth surface feel for a mask pack nonwoven fibrous aggregate
application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 shows the cross-section of a monofilament included in
a lyocell fiber according to one embodiment of the present
invention.
[0029] FIG. 2 is a photograph showing the cross-section of a
lyocell fiber prepared according to an example of the present
invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0030] Hereinafter, the present invention will be explained in more
detail.
[0031] The present invention relates to a lyocell fiber including a
lyocell multifilament prepared by spinning a lyocell spinning dope
including cellulose pulp and a solvent, wherein a monofilament
making up the multifilament has a cross-section having a central
major axis (L1) and a central minor axis (S1), a ratio of lengths
of the central major axis (L1) and the central minor axis (S1) is
1.5:1.about.10.5:1, and a ratio of the length of the central major
axis (L1) and a length of a straight line (L2) between both ends of
the central major axis is 1.0.about.1.5:1.
[0032] The lyocell fiber of the present invention includes
monofilaments having a flat yarn cross-section, and the
cross-section is as shown in FIG. 1.
[0033] That is, since the length of the central major axis (L1) is
at least 1.5 times and at most 10.5 times the length of the central
minor axis (S1), it becomes a flat yarn having a flat
cross-section, and in case the ratio of the length of the central
major axis (L1) and the length of a straight line (L2) between both
ends of the central major axis is 1:1, a linear flat yarn is
formed, while in case the ratio is greater than 1:1, a flat yarn
having a curvature is formed.
[0034] As such, since the monofilament has a cross-section of a
flat yarn or a flat yarn having a curvature, physical properties
that could not be exhibited by the existing lyocell fiber having a
circular cross-section may be exhibited, and particularly,
excellent bendability may be exhibited for industrial material
applications, good feel and soft gloss may be exhibited for clothes
or interior applications, and transparency, skin adhesion,
absorption and maintenance of a solvent such as moisture, and
smooth surface feel may be exhibited for a mask pack nonwoven
fibrous aggregate application.
[0035] Meanwhile, the cross-section has a central major axis (L1)
and a central minor axis (S1), and the ratio of the lengths of the
central major axis (L1) and the central minor axis (S1) should be
1.5:1.about.10.5:1, and if the ratio is less than 1.5:1, a flat
yarn property may be insignificantly exhibited, and thus it may be
difficult to exhibit properties that are significantly different
from a yarn having a circular cross-section, and if it exceeds
10.5:1, it may be difficult to adjust desired fineness of the final
fiber.
[0036] Further, the ratio of the length of the central major axis
(L1) and the length of a straight line (L2) between both ends of
the central major axis is 1.0.about.1.5:1, preferably
1.1:1.about.1.5:1. If the ratio is greater than 1.5:1, a curvature
may become excessively large, and thus adhesion between fibers may
be lowered and the effect of a flat yarn may be decreased.
[0037] In addition, the monofilament of the present invention is
characterized in that the length of the central major axis (L1) is
12.about.42 .mu.m, and the length of the central minor axis (S1) is
4.about.7 .mu.m, which can be prepared in the monofilament fineness
range of 1.0.about.4.0 denier as defined in the present
invention.
[0038] That is, a length of the central minor axis (S1) of less
than 4 .mu.m is difficult to achieve due to the limitation in the
technology of spinneret manufacture and processing, and fineness
should be increased so that the length of the central major axis
(L1) is greater than 42 .mu.m, which is insignificant in terms of
fiber fineness. In case the length of the central minor axis (S1)
is greater than 7 .mu.m and the length of the central major axis
(L1) is less than 12 .mu.m, a specific surface area may decrease
and adhesion between fibers may be lowered.
[0039] Further, since the monofilament of the present invention has
fineness of 1.0.about.4.0 denier, and a value obtained by dividing
the cross-sectional perimeter of the monofilament by the fineness
is 22 .mu.m/denier or more, preferably 24.5 to 32 .mu.m/denier, the
cross-sectional perimeter per unit fineness increases and the
specific surface area of the monofilament itself increases, and
thus it may be applied in effective fields, and for example, it may
have excellent absorption and maintenance of essence in a mask pack
nonwoven fibrous aggregate.
[0040] The above-explained lyocell fiber is biodegradable and
environmentally friendly, and the monofilament of the lyocell fiber
has a cross-section of a linear flat yarn or a flat yarn having a
curvature, and thus, compared to a common circular cross-section,
bendability for withstanding to external force is strong, and the
fiber strand specularly reflects light like a mirror, thus having a
shiny gloss on the surface. In addition, the feel is rough yet soft
due to a special cross-section effect, and thus it may be applied
in various fields including industrial materials, cloth
applications such as a car seat cover, a seat cover, a carpet, a
curtain, various clothes, and the like.
[0041] Particularly, in case the lyocell fiber according to the
present invention is prepared in the form of a short staple fiber
and is used as a nonwoven fibrous aggregate for a mask pack, it may
exhibit excellent properties of transparency, skin adhesion,
essence absorption and maintenance, soft feel, and the like, which
are very important properties of a nonwoven fibrous aggregate for a
mask pack, compared to other materials.
[0042] If the cross-section of the fiber is flat, the thickness of
the fiber decreases, and when prepared into a nonwoven fibrous
aggregate, based on the same unit weight, the thickness of the
nonwoven fibrous aggregate becomes thinner compared to a common
circular cross-section fiber, and thus if dipped in a cosmetic
solvent such as an essence, it may become transparent and have a
soft feel and exhibit excellent skin adhesion.
[0043] Further, since the specific surface area is large compared
to a circular cross-section fiber of the same fineness, absorption
for solvents such as an essence is high, and thus essence
maintenance is also excellent, thereby exhibiting large advantages
compared to other materials applied for a nonwoven fibrous
aggregate for a mask pack.
[0044] In case the lyocell fiber according to the present invention
is used as a nonwoven fibrous aggregate for a mask pack, it may
have fineness of 1.0 to 4.0 denier. Herein, a lyocell fiber having
fineness of less than 1.0 denier may be difficult to prepare, and
if the fineness of the lyocell fiber is greater than 4.0 denier, it
is more than general fineness applied for a mask pack, and thus
there is no distinction in skin adhesion or essence absorption and
the like, and the properties of a general level may be
exhibited.
[0045] The lyocell fiber may have a fiber length of 36 to 40 mm. In
case the lyocell fiber is used as a nonwoven fibrous aggregate for
a mask pack within the above fiber length range, during the
preparation process of a nonwoven fibrous aggregate, processability
in a carding process may be excellent.
[0046] The crimp number of the lyocell fiber may be 8 to 12 cpi.
The crimp number may be 5 to 20 cpi, but preferably 8 to 12 cpi.
Herein, if the crimp number is less than 5 cpi, during the
preparation process of a nonwoven fibrous aggregate, in a carding
process, fiber entanglement may be low, thus generating a process
problem, and if it is greater than 20 cpi, due to too high a crimp
number, opening may not be properly achieved in a carding
process.
[0047] The emulsion content of the lyocell fiber may be 0.1 to 0.4
wt %, based on 100 wt % of the lyocell fiber. If the emulsion
content is within the above wt % range, during the process of
forming filaments into crimped tow as described below, generated
friction may be reduced, and crimps between fibers may be properly
formed. Further, cardability during the preparation of a nonwoven
fibrous aggregate may be improved.
[0048] The basis weight of the nonwoven fibrous aggregate may be 30
to 60 g/m.sup.2, and the thickness may be 0.3 to 0.5 mm. The above
basis weight and thickness ranges mean optimum ranges for improving
absorption of a liquid composition, transparency, and adhesion in a
nonwoven fibrous aggregate containing the lyocell fiber fulfilling
the above-described fineness, fiber length, crimp number, and
emulsion content.
[0049] The moisture absorption of the nonwoven fibrous aggregate
may be 1000 to 1600%, based on the weight of the lyocell fiber. As
explained above, although the lyocell fiber is hydrophilic and has
relatively high moisture absorption compared to other fibers, in
case the above-described properties of a lyocell fiber are
fulfilled, and simultaneously the above-described basis weight and
thickness ranges of a nonwoven fibrous aggregate are fulfilled, the
moisture absorption of a nonwoven fibrous aggregate containing the
lyocell fiber may be adjusted to the above range.
[0050] The nonwoven fibrous aggregate may have transparency after
moisture treatment of 80 to 84%, compared to before moisture
treatment, and transparency after essence treatment of 88 to 94%,
compared to before essence treatment. Since the fineness of the
lyocell fiber is 1.0 to 4.0 denier, and thus the thickness of the
nonwoven fibrous aggregate containing the lyocell fiber becomes
thinner than usual, if the nonwoven fibrous aggregate is dipped in
a liquid composition such as moisture and an essence and the like,
it may have transparency within the above range as well as a soft
feel.
[0051] The skin adhesion after moisture treatment of the nonwoven
fibrous aggregate may be 3.6 to 4.2 gf, and the skin adhesion after
essence treatment of the nonwoven fibrous aggregate may be 4.5 to
5.3 gf. In case the properties of the lyocell fiber are fulfilled,
and simultaneously the basis weight and thickness of the nonwoven
fibrous aggregate containing the same are fulfilled, the nonwoven
fibrous aggregate may fulfill skin adhesion of the above range.
[0052] The nonwoven fibrous aggregate may have an emulsion content
of 0.001 wt % or less, based on 100 wt % of the nonwoven fibrous
aggregate. The nonwoven fibrous aggregate exhibits the above
emulsion content because most of the emulsion contained in the
lyocell fiber is washed away during hydroentanglement of a spunlace
process when preparing a nonwoven fabric.
[0053] Hereinafter, the nonwoven fibrous aggregate containing the
lyocell fiber will be explained in detail through the preparation
process of the nonwoven fibrous aggregate.
[0054] The nonwoven fibrous aggregate of the present invention may
be prepared by a method including the steps of: (S1) spinning a
lyocell spinning dope including cellulose pulp and a solvent; (S2)
coagulating the lyocell spinning dope spun in the step (S1); (S3)
washing the lyocell multifilament obtained in the step (S2); (S4)
treating the lyocell multifilament washed in the step (S3) with an
emulsion; (S5) crimping the lyocell multifilament emulsion-treated
in the step (S4) through a stuffer box to obtain a crimped tow;
(S6) drying and cutting the crimped tow obtained in the step (S5)
to obtain lyocell staple fiber; and (S7) preparing the lyocell
staple fiber obtained in the step (S6) into a nonwoven fibrous
aggregate, wherein a monofilament making up the multifilament has a
cross-section having a central major axis (L1) and a central minor
axis (S1), the ratio of the lengths of the central major axis (L1)
and the central minor axis (S1) is 1.5:1.about.10.5:1, and the
ratio of the length of the central major axis (L1) and the length
of a straight line (L2) between both ends of the central major axis
is 1.0.about.1.5:1.
[0055] The lyocell fiber of the present invention may prepared by
dissolving cellulose pulp in a solvent to prepare a lyocell
spinning dope, and then, spinning the spinning dope, wherein the
solvent may be selected from an aqueous solution of
N-methylmorpholine N-oxide (NMMO) or an ionic solvent, and
hereinafter, a method of preparing the lyocell fiber using an
aqueous solution of NMMO will be explained in more detail.
[0056] [(S1) STEP]
[0057] In the (S1) step, a lyocell spinning dope including
cellulose pulp and an aqueous solution of NMMO is spun.
[0058] The lyocell spinning dope may include: 6.about.16 wt % of
cellulose pulp; and 84.about.94 wt % of N-methylmorpholine N-oxide,
wherein the cellulose pulp may have an alpha-cellulose content of
85.about.97 wt % and a polymerization degree (DPw) of
600.about.1700.
[0059] In the lyocell spinning dope, if the content of cellulose
pulp is less than 6 wt %, it may be difficult to realize fiber
properties, and if it is greater than 16 wt %, it may be difficult
to dissolve in an aqueous solution.
[0060] Further, in the lyocell spinning dope, if the content of
N-methylmorpholine N-oxide is less than 84 wt %, the melt viscosity
may significantly increase, which is not preferable, and if it is
greater than 94 wt %, spinning viscosity may significantly
decrease, and thus, it may be difficult to prepare homogeneous
fiber in a spinning step.
[0061] In the aqueous solution of N-methylmorpholine N-oxide, the
weight ratio of N-methylmorpholine N-oxide and water may be 93:7 to
85:15. If the weight ratio of N-methylmorpholine N-oxide and water
exceeds 93:7, a melting temperature may increase, thus generating
decomposition of cellulose when dissolving the cellulose, and if
the weight ratio is less than 85:15, the dissolving performance of
the solvent may be lowered, and thus it may be difficult to
dissolve the cellulose.
[0062] The above-described spinning dope is discharged from a
spinning nozzle of a spinneret. Herein, the spinneret performs a
function for discharging the spinning dope in the form of a
filament into a coagulation solution in a coagulation bath through
an air gap section.
[0063] The spinneret may have a shape wherein spinneret holes in
the form of flat and long slits are curved in a C-shape.
[0064] The arrangement of the spinneret holes in the spinneret is
very important, and they should be designed so that all the holes
may contact cooling air and may not interfere with each other
during air quenching.
[0065] The step of discharging the spinning dope from the spinneret
may be conducted at a spinning temperature of 80.about.130.degree.
C.
[0066] [(S2) STEP]
[0067] In the step (S2), the lyocell spinning dope spun in the step
(S1) is coagulated to obtain a lyocell multifilament, and the
coagulation of the step (S2) may include a primary coagulation step
of air quenching (Q/A) wherein cooling air is supplied to the
spinning dope to coagulate, and a secondary coagulation step
wherein the primarily coagulated spinning dope is dipped in a
coagulation solution to coagulate.
[0068] In the step (S1), after discharging the spinning dope
through a spinneret, it may be passed through an air gap section
between the spinneret and the coagulation bath. In the air gap
section, cooling air is supplied from an air cooling part
positioned inside of a donut-shaped spinneret, from the inside to
the outside of the spinneret, and primary coagulation may be
conducted by air quenching wherein such cooling air is supplied to
the spinning dope.
[0069] Herein, factors influencing the properties of the lyocell
multifilament obtained in the step (S2) include the temperature and
wind velocity of the cooling air in the air gap section, and in the
coagulation of the step (S2), cooling air having a temperature of
4.about.15.degree. C. and a wind velocity of 5.about.10 m/s may be
supplied to the spinning dope to coagulate.
[0070] If the temperature of the cooling air during the primary
coagulation is less than 4.degree. C., the surface of a spinneret
may be cooled, the cross-section of the lyocell filament may become
non-uniform, and spinnability may become inferior, and if it is
greater than 15.degree. C., primary coagulation by cooling air may
not be sufficiently achieved, and thus spinnability may become
inferior.
[0071] Further, a flat yarn is very sensitive to the wind velocity
of air quenching during spinning, and if the wind velocity of the
cooling air during the primary coagulation is less than 5 m/s,
primary coagulation by the cooling air may not be sufficiently
achieved, and thus spinnability may become inferior and yarn
cutting may be easily generated, and if it is greater than 10 m/s,
the spinning dope discharged from the spinneret may have a flat
yarn cross-section, and thus the length of the central minor axis
may become small, spinnability may not be good due to shaking by
air quenching, and yarn cutting may be generated.
[0072] After the primary coagulation by air quenching, the spinning
dope may be fed to a coagulation bath containing a coagulation
solution to progress secondary coagulation. In order to progress
appropriate secondary coagulation, the temperature of the
coagulation solution may be equal to or less than 30.degree. C.
Such a secondary coagulation temperature is not higher than is
necessary, and appropriately maintains a coagulation velocity. The
coagulation solution may be prepared with a common composition in
the technical field to which the present invention pertains, and
thus is not specifically limited.
[0073] [(S3) STEP]
[0074] In the step (S3), the lyocell multifilament obtained in the
step (S2) is washed.
[0075] Specifically, the lyocell multifilament obtained in the step
(S2) is introduced into a tow roller, and then introduced into a
washing bath to wash it.
[0076] In the filament washing step, considering easy recovery and
reuse of a solvent after washing, a washing solution of a
temperature of 0 to 100.degree. C. may be used, and as the washing
solution, water may be used, and if necessary, other additive
ingredients may be further included.
[0077] [(S4) STEP]
[0078] In the step (S4), the lyocell multifilament washed in the
step (S3) is treated with an emulsion, and after the emulsion
treatment, it may be dried.
[0079] In the emulsion treatment, the multifilament is coated with
an emulsion while passing through the surface of a roller coated
with an emulsion, and the amount of an emulsion coated on the
filament is controlled by the velocity of the roller of emulsion
treatment equipment. The emulsion reduces friction generated during
the contact of the filament in a drying roller and guide, in a
winding or crimping step, and allows proper formation of crimp.
[0080] [(S5) STEP]
[0081] In the step (S5), the lyocell multifilament emulsion-treated
in the step (S4) is crimped to obtain a crimped tow.
[0082] Crimping is a process of providing crimps to the
multifilament, and specifically, a crimped tow having 8.about.12
crimps per inch may be obtained by crimping with a stuffer box.
[0083] In the step (S5), steam may be supplied to the lyocell
multifilament and pressure may be applied to crimp.
[0084] Specifically, the lyocell multifilament is passed through a
steam box, steam is supplied at a rate of 0.1.about.1.0
kgf/cm.sup.3 to increase the temperature, and then is pressed using
a press roller under pressure of 1.5.about.3.0 kgf/cm.sup.3,
thereby forming crimps in a stuffer box.
[0085] Herein, if the feed rate of steam is less than 0.1
kgf/cm.sup.3, crimps may not be smoothly formed, and if it is
greater than 1.0 kgf/cm.sup.3, a temperature in the stuffer box may
increase above 120.degree. C., and thus filaments may be adhered to
each other and may not pass through the stuffer box. Further, if
the pressure for pressing the press roller is less than 1.5
kgf/cm.sup.3, a desired number of crimps may not be formed, and if
it is greater than 3.0 kgf/cm.sup.3, a pressing force may be too
strong, and thus filaments may not pass through the stuffer
box.
[0086] [(S6) STEP]
[0087] In the step (S6), the crimped tow obtained in the step (S5)
is dried and cut to obtain lyocell staple fiber.
[0088] The crimped tow is dried using a lattice dryer, and is
subjected to a cutting process to form lyocell staple fiber.
[0089] [(S7) STEP]
[0090] In the step (S7), the lyocell staple fiber obtained in the
step (S6) is prepared into a nonwoven fibrous aggregate.
[0091] The lyocell staple fiber is hydroentangled by carding and
spun lacing to prepare a nonwoven fibrous aggregate.
[0092] The present invention may be used as a cosmetic mask pack
using a mask pack sheet. Since the mask pack uses the mask pack
sheet as a support sheet, it has improved skin adhesion and
wearability even in the face region having many curves, and has
excellent absorption of a liquid composition such as moisture and
essence, and the like, and thus can effectively supply nutrition to
the face region.
[0093] Further, since it has improved wet transparency, when
adhered to the face of a user, it appears similar to the face color
of a user, makes an apparent sense of difference less, thus making
the appearance after wearing the mask pack beautiful.
[0094] Hereinafter, the present invention will be explained in more
detail through examples. These examples are presented only to
explain the present invention in more detail, and it would be
obvious to one of ordinary knowledge in the art that the scope of
the present invention is not limited by these examples.
Experimental Example 1
Example 1
[0095] Cellulose pulp having a polymerization degree (DPw) of 820
and an alpha cellulose content of 93.9% was mixed with a mixed
solvent of NMMO/H.sub.2O (weight ratio 90/10) having a propyl
gallate content of 0.01 wt % to prepare a spinning dope for
preparing lyocell fiber of a concentration of 10 wt %.
[0096] First, in the spinning nozzle of a spinneret in which
multiple unit holes in the form of a flat slit having a curvature
are formed, a spinning temperature was maintained at 110.degree.
C., and the discharge amount of a spinning dope and the spinning
velocity were controlled so that the fineness of the monofilament
may became 2.0 denier. The filament-shaped spinning dope discharged
from the spinning nozzle was passed through an air gap section and
fed to a coagulation solution in a coagulation bath. Herein, the
cooling air in the air gap section primarily coagulates the
spinning dope at a temperature of 8.degree. C. and a wind velocity
of 5.about.7 m/s.
[0097] As the coagulation solution, a solution of a temperature of
25.degree. C. including 85 wt % of water and 15 wt % of NMMO was
used.
[0098] The filament drawn from the air layer through a tow roller
was washed by a sprayed washing solution in a washing machine to
remove remaining NMMO, and the filament was allowed to be uniformly
coated with an emulsion to maintain the emulsion content of 0.2%,
and dried at 150.degree. C. in a drying roller, thus preparing
lyocell fiber including multifilaments consisting of monofilaments
having a cross-section of flat yarn having a curvature.
Example 2
[0099] Lyocell fiber including multifilaments consisting of
monofilaments having a cross-section of a flat yarn having a
curvature was prepared by the same method as Example 1, except that
the fineness of the monofilament was controlled to 1.6 denier.
Example 3
[0100] Lyocell fiber including multifilaments consisting of
monofilaments having a cross-section of a flat yarn having a
curvature was prepared by the same method as Example 1, except that
the fineness of the monofilament was controlled to 2.4 denier.
Comparative Example 1
[0101] Lyocell fiber including multifilaments consisting of
monofilaments having a circular cross-section with a diameter of
13.78 .mu.m was prepared by the same method as Example 1, except
that a spinneret having multiple circular unit holes was used, the
wind velocity during air quenching was 15 m/s, and the fineness of
the monofilament was controlled to 2.0 denier.
Comparative Example 2
[0102] Lyocell fiber including multifilaments consisting of
monofilaments having a circular cross-section with a diameter of
15.06 .mu.m was prepared by the same method as Comparative Example
1, except that the fineness of the monofilament was controlled to
2.39 denier.
Comparative Example 3
[0103] Lyocell fiber was prepared by the same method as Example 1,
except that the ratio of the central major axis (L1) of the
monofilament and the straight line (L2) between both ends of the
central major axis was controlled to less than 1.0.
Comparative Example 4
[0104] Lyocell fiber including multifilaments consisting of
monofilaments having a cross-section of a flat yarn having a
curvature was prepared by the same method as Example 1, except that
the ratio of the central major axis (L1) of the monofilament and
the straight line (L2) between both ends of the central major axis
was controlled to 2.8:1.
Comparative Example 5
[0105] Lyocell fiber was prepared by the same method as Example 1,
except that the length of the central major axis (L1) of the
monofilament was 11 .mu.m and the length of the central minor axis
(S1) was 3 .mu.m.
Comparative Example 6
[0106] Lyocell fiber including multifilaments consisting of
monofilaments having a cross-section of a flat yarn having a
curvature was prepared by the same method as Example 1, except that
the length of the central major axis (L1) of the monofilament was
43 .mu.m and the length of the central minor axis (S1) was 8
.mu.m.
[0107] For the lyocell fibers prepared in the examples and
comparative examples, the cross-sectional shape of the monofilament
included in the lyocell fiber, the cross-sectional area, fineness,
and fiber thickness were measured and calculated as follows, and
the results are shown in the following Table 1.
[0108] (1) The Cross-Sectional Shape of the Monofilament Included
in Lyocell Fiber
[0109] A small amount of fiber bundles were sampled, rolled
together with black cotton and made thin, and inserted into the
holes of a plate capable of cutting the cross-section, and then cut
with a razor blade so that the cross-section may not be shaved.
[0110] Using an optical microscope (BX51, product from Olympus),
the cross-section was observed with a magnification (.times.500),
and the image was stored with a digital camera. For the
cross-section image of the fiber, using an Olympus soft imaging
solution program, the cross-section to be obtained was designated,
and the lengths of the major axis and minor axis and the area,
fiber thickness, cross-sectional perimeter, and the like were
analyzed.
[0111] (2) Fineness
[0112] Using the practical monofilament cross-sectional area of
lyocell fiber obtained through the cross-section analysis and the
density of lyocell fiber (1.49 g/cm.sup.3), the fineness of the
lyocell fiber was calculated by the following Equation 1.
Fineness (De)=[monofilament cross-sectional area of lyocell fiber
(.mu.m.sup.2).times.density of lyocell fiber
(g/cm.sup.3).times.9000 (m)]/1000000 <Equation 1>
TABLE-US-00001 TABLE 1 Cross-sectional shape of monofilament
Practical Length Length Length of monofilament of of straight line
cross- Cross- central central connecting Cross- sectional sectional
major minim both ends sectional area of perimeter axis axis of the
major perimeter lyocell Fineness (.mu.m)/fineness L1/ L1/ (L1,
.mu.m) (S1, .mu.m) axis (L2, .mu.m) (.mu.m) fiber (.mu.m.sup.2)
(De) (De) S1 L2 Note Example 1 23.8 5.9 19.8 61.0 148.9 2.0 30.5
4.0 1.2 Flat yarn cross- section Example 2 20.2 5.8 18.2 53.8 124.1
1.6 32.4 3.4 1.1 Flat yarn cross- section Example 3 29.0 6.20 21.0
69.7 178.4 2.4 29.2 4.7 1.4 Flat yarn cross- section Comparative
circular cross-section 43.2 149.0 2.0 21.6 Circular Example 1
diameter: 13.7 cross- section Comparative circular cross-section
47.3 178.0 2.4 19.8 Circular Example 2 diameter: 15.0 cross-
section Comparative Not spun Not measurable Example 3 Comparative
34.5 4.22 12.2 77.8 146.4 1.95 39.9 8.1 2.8 Flat Example 4 yarn
cross- section Comparative Not spun Not measurable Example 5
Comparative 43.1 8.8 18.2 104.4 380.4 5.0 20.6 4.8 2.3 Flat Example
6 yarn cross- section
[0113] As shown in Table 1, the lyocell fibers of Examples 1 to 3
consisting of monofilaments having a cross-section of a flat yarn
and having a curvature have larger cross-sectional perimeters at
the same fineness, compared to the lyocell fibers of Comparative
Examples 1 and 2 consisting of monofilaments having a circular
cross-section. This means that the specific surface area of the
fiber is large, thus realizing excellent properties as described
above. Further, since the fiber thickness is small at the same
fineness, excellent properties may be exhibited. In addition, since
the lyocell fibers of Examples 1 to 3 do not have excessively large
curvatures compared to the lyocell fibers of Comparative Examples 3
to 6, they have excellent adhesion between fibers and thus have an
improved flat yarn effect, and have an effective range exhibiting
excellent effect in terms of fiber fineness.
[0114] Herein, the cross-sectional shape of the lyocell fiber of
Example 1 is as shown in FIG. 2.
[0115] From these results, it can be seen that the lyocell fibers
of Examples 1 to 3 have large specific surface areas and small
fiber thicknesses, and may be broadly applied in fields requiring
such properties.
Experimental Example 2
[0116] The lyocell fibers prepared in the examples and comparative
examples were passed through a steam box (with a pressure condition
of 0.2 kgf/cm.sup.2) and preheated, and pressed under pressure of
2.0 kgf/cm.sup.2 using a stuffer box press roller, thus preparing a
crimped tow in a stuffer box, which is dried through a lattice
dryer, and then finally cut to prepare a lyocell staple fiber
having a fiber length of 38 mm.
[0117] The above-prepared lyocell staple fiber was finally prepared
into a nonwoven fibrous aggregate through carding and spun lacing
processes, the raw material input and process velocity were
controlled to adjust the basis weight of the nonwoven fibrous
aggregate to the numerical values of Table 2, and the deviation in
the basis weight of the nonwoven fibrous aggregate was adjusted to
.+-.10%.
[0118] The properties of the above-prepared nonwoven fibrous
aggregate were measured as follows and are shown in the following
Table 2.
[0119] <Measurement Method>
[0120] (1) Basis Weight (gsm=g/m.sup.2)
[0121] The nonwoven fibrous aggregate was sampled with a width of 5
cm and a length of 20 cm, the weight was measured, and the basis
weight was calculated by the following Equation 2.
Basis weight=measured value of the weight of the nonwoven fibrous
aggregate sample.times.100 <Equation 2>
[0122] (2) Thickness
[0123] The thickness was measured using a No. 2046F dial indicator
from Mitutoyo Corporation.
[0124] (3) Transparency
[0125] Sample pretreatment: The nonwoven fibrous aggregate was
dipped in water or essence for 10 minutes.
[0126] In order to measure the transparency of the nonwoven fibrous
aggregate, transmittance of a nanometer wavelength was measured
using light transmittance measuring equipment, Haze Meter (Nippon
Denshoku Industries, NDH-5000).
[0127] (4) Absorption
[0128] The weights before and after dipping the nonwoven fibrous
aggregate in water or essence for 10 minutes were measured, and the
capacity of the nonwoven fibrous aggregate for absorbing water or
essence was calculated by the following Equation 3.
Absorption (%)={(weight of nonwoven fibrous aggregate after
dipping-weight of nonwoven fibrous aggregate before dipping)/weight
of nonwoven fibrous aggregate before dipping}.times.100
<Equation 3>
[0129] (5) Skin Adhesion
[0130] The nonwoven fibrous aggregate was cut to a 25 mm.times.150
mm size, and dipped in water or essence for 10 minutes, and then
adhered to the upper limb of a person. Immediately after adhering,
while tearing off the nonwoven fibrous aggregate from the skin
using an Instron instrument (Instron-3365), adhesion force (unit of
gf) was measured.
TABLE-US-00002 TABLE 2 Basis weight Thickness Transparency
Absorption Skin adhesion (gsm) (mm) (%) (%) (%) Example 1 50 0.42
Water 82 Water 1200 Water 3.8 Essence 90 Essence 1400 Essence 4.9
Example 2 40 0.39 Water 84 Water 1100 Water 3.7 Essence 92 Essence
1250 Essence 4.7 Example 3 60 0.46 Water 81 Water 1300 Water 4.0
Essence 88 Essence 1500 Essence 5.1 Comparative 40 0.45 Water 79
Water 950 Water 3.3 Example 1 Essence 88 Essence 1000 Essence 4.3
Comparative 50 0.5 Water 78 Water 1000 Water 3.5 Example 2 Essence
86 Essence 1100 Essence 4.5 Comparative Not measurable -- -- -- --
Example 3 Comparative 50 0.44 Eater 80 Easter 1200 Eater 3.6
Example 4 Essence 88 Essence 1400 Essence 4.6 Comparative Not
measurable -- -- -- -- Example 5 Comparative 60 0.52 Water 74 Water
1400 Water 3.8 Example 6 Essence 82 Essence 1600 Essence 4.8
[0131] As shown in the Table 2, Examples 1 to 3 had thinner
thicknesses than the nonwoven fibrous aggregates of Comparative
Examples 1 and 2, but exhibited excellent performances including
transparency, absorption, and adhesion, due to the effect of the
flat fiber cross-section having a curvature.
[0132] To the contrary, the fiber of Comparative Example 4 had an
excessively high curvature of fiber, and thus the thickness
increased during the preparation of the nonwoven fibrous aggregate,
and the properties other than absorption were similar to those of
Comparative Examples 1 and 2. In Comparative Example 6, the
thickness of the fiber having a curvature increased and the
thickness of the nonwoven fibrous aggregate increased, and thus,
compared to Example 3, the properties may not be improved, and it
is not expected to be useful for a mask sheet.
[0133] Although specific embodiments of the present invention have
been described in detail, it would be obvious to one of ordinary
knowledge in the art that such specific technologies are no more
than preferable examples, and the scope of the present invention is
not limited thereby. Therefore, the substantial scope of the
present invention is defined by the claims attached hereto and
equivalents thereof.
INDUSTRIAL AVAILABILITY
[0134] The present invention is applicable to a mask pack
sheet.
* * * * *