U.S. patent application number 16/623683 was filed with the patent office on 2020-06-04 for nonwoven fabric for skin care products.
This patent application is currently assigned to Toray Industries, Inc.. The applicant listed for this patent is Toray Industries, Inc.. Invention is credited to Hiroshi Kajiyama, Makoto Nakahara, Kumi Oyama.
Application Number | 20200170382 16/623683 |
Document ID | / |
Family ID | 64737233 |
Filed Date | 2020-06-04 |
United States Patent
Application |
20200170382 |
Kind Code |
A1 |
Oyama; Kumi ; et
al. |
June 4, 2020 |
NONWOVEN FABRIC FOR SKIN CARE PRODUCTS
Abstract
Provided is a nonwoven fabric for skin care products. The
nonwoven fabric includes: a thermoplastic resin fiber having a
single fiber diameter of 50 nm or more and 800 nm or less; and a
cellulose fiber having a tensile strength measured in accordance
with JIS L 1015:2010 8.7.2 of 1.9 cN/dtex or less. A total content
of the thermoplastic resin fiber and the cellulose fiber is 85% by
mass or more relative to a total mass of the nonwoven fabric for
skin care products, and a content ratio by mass of the
thermoplastic resin fiber and the cellulose fiber (Thermoplastic
resin fiber/Cellulose fiber) is 0.06 to 0.22.
Inventors: |
Oyama; Kumi; (Otsu-shi,
Shiga, JP) ; Kajiyama; Hiroshi; (Otsu-shi, Shiga,
JP) ; Nakahara; Makoto; (Otsu-shi, Shiga,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Toray Industries, Inc. |
Tokyo |
|
JP |
|
|
Assignee: |
Toray Industries, Inc.
Tokyo
JP
|
Family ID: |
64737233 |
Appl. No.: |
16/623683 |
Filed: |
June 20, 2018 |
PCT Filed: |
June 20, 2018 |
PCT NO: |
PCT/JP2018/023435 |
371 Date: |
December 17, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D04H 1/498 20130101;
D04H 1/425 20130101; A61K 8/0212 20130101; A45D 44/002 20130101;
B32B 2262/0276 20130101; D04H 1/4382 20130101; A45D 44/22 20130101;
D04H 1/435 20130101; A45D 2200/1027 20130101 |
International
Class: |
A45D 44/00 20060101
A45D044/00; D04H 1/425 20060101 D04H001/425 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 21, 2017 |
JP |
2017-121223 |
Claims
1. A nonwoven fabric for skin care products, the nonwoven fabric
comprising: a thermoplastic resin fiber having a single fiber
diameter of 50 nm or more and 800 nm or less; and a cellulose fiber
having a tensile strength measured in accordance with JIS L
1015:2010 8.7.2 of 1.9 cN/dtex or less, wherein a total content of
the thermoplastic resin fiber and the cellulose fiber is 85% by
mass or more relative to a total mass of the nonwoven fabric for
skin care products, and a content ratio by mass of the
thermoplastic resin fiber and the cellulose fiber (Thermoplastic
resin fiber/Cellulose fiber) is 0.06 to 0.22.
2. The nonwoven fabric for skin care products according to claim 1,
wherein the thermoplastic resin fiber is a polyamide fiber.
3. The nonwoven fabric for skin care products according to claim 1,
wherein the cellulose fiber is rayon.
4. The nonwoven fabric for skin care products according to claim 1,
wherein a fiber length of the cellulose fiber is 35 mm or more.
5. A face mask comprising the nonwoven fabric for skin care
products according to claim 1.
6. A cleansing sheet comprising the nonwoven fabric for skin care
products according to claim 1.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is the U.S. National Phase application of
PCT/JP2018/023435, filed Jun. 20, 2018, which claims priority to
Japanese Patent Application No. 2017-121223, filed Jun. 21, 2017,
the disclosures of these applications being incorporated herein by
reference in their entireties for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to a nonwoven fabric for skin
care products.
BACKGROUND OF THE INVENTION
[0003] Sheet-like skin care cosmetics represented by face masks and
cleansing sheets are used for various purposes such as penetration
of a facial lotion into a skin and removal of cosmetics. The face
mask can retain the facial lotion on the surface of skin for a
certain period of time and thus allows the facial lotion to be
sufficiently penetrated into the skin as compared with conventional
skin care products applied directly to the skin. In addition, the
cleansing sheet provides a high cleansing effect due to both
removal of the cosmetic by a cleansing agent and removal effect by
the contact of the sheet with the skin. Due to the above-described
excellent performance, various commercial products have been
developed as the sheet-like skin care products.
[0004] Recently, it has been known that a nonwoven fabric including
a polyester fiber having a single fiber diameter of 500 nm to 1000
nm and a polyester fiber having a single fiber diameter of 10 .mu.m
to 100 .mu.m is formed, whereby a product obtained by immersing
this nonwoven fabric into a cleansing agent or the like allows the
wipeability of cosmetics attaching to skin to be improved (Patent
Literature 1).
[0005] In addition, it has been known that a nonwoven fabric
including fibers made of a thermoplastic resin having a single
fiber diameter of 1 nm to 500 nm and a fiber having a tensile
strength at the time of a wet state of 2.0 cN/dtex or more is
formed, whereby a product obtained by immersing this nonwoven
fabric into a cleansing agent has excellent strength at the time of
a wet state and, in addition, improved adhesion to a skin and
wipeability of a cosmetic attached to skin (Patent Literature
2).
Patent Literature
[0006] Patent Literature 1: Japanese Laid-open Patent Publication
No. 2011-6807
[0007] Patent Literature 2: Japanese Laid-open Patent Publication
No. 2009-97121
SUMMARY OF THE INVENTION
[0008] The polyester fiber having a single fiber diameter of 10
.mu.m to 100 .mu.m included in the nonwoven fabric disclosed in
Patent Literature 1 (hereinafter, may be referred to as the known
nonwoven fabric 1) has high tensile strength at the time of a wet
state. In addition, the known nonwoven fabric 1 includes 30% by
mass to 97% by mass of the fiber. Thus, although the skin care
product obtained by immersing the known nonwoven fabric 1 into a
cleansing agent or a cosmetic has excellent strength at the time of
a wet state, the skin care product has problems of insufficient
adhesion to skin (in particular, adhesion when a certain time has
passed after use of the skin care product) and insufficient
wipeability of the cosmetics attached to the skin.
[0009] The nonwoven fabric disclosed in Patent Literature 2
(hereinafter, referred to as the known nonwoven fabric 2) also has
the same problems as the problems of the known nonwoven fabric 1.
In other words, the known nonwoven fabric 2 includes the fiber
having a high tensile strength at the time of a wet state of 2.0
cN/dtex or more and thus the skin care product obtained by
immersing the known nonwoven fabric 2 into a cleansing agent or a
cosmetic has excellent strength at the time of a wet state.
However, the skin care product has problems of insufficient
adhesion to skin (in particular, adhesion when a certain time has
passed after use of the skin care product) and insufficient
wipeability of the cosmetic attached to the skin.
[0010] Therefore, in view of the above-described problems, an
object of the present invention is to provide a nonwoven fabric for
skin care products having excellent handleability as a skin care
product and having excellent adhesion to skin and having excellent
wipeability of cosmetic attached to skin as the skin care
product.
Solution to Problem
[0011] To solve the problem described above, the present invention
includes the following configuration. [0012] (1) A nonwoven fabric
for skin care products, the nonwoven fabric including: a
thermoplastic resin fiber having a single fiber diameter of 50 nm
or more and 800 nm or less; and a cellulose fiber having a tensile
strength measured in accordance with JIS L 1015:2010 8.7.2 of 1.9
cN/dtex or less, wherein a total content of the thermoplastic resin
fiber and the cellulose fiber is 85% by mass or more relative to a
total mass of the nonwoven fabric for skin care products, and a
content ratio by mass of the thermoplastic resin fiber and the
cellulose fiber (Thermoplastic resin fiber/Cellulose fiber) is 0.06
to 0.22. [0013] (2) The nonwoven fabric for skin care products
according to (1), wherein the thermoplastic resin fiber is a
polyamide fiber. [0014] (3) The nonwoven fabric for skin care
products according to (1) or (2), wherein the cellulose fiber is
rayon. [0015] (4) The nonwoven fabric for skin care products
according to any one of (1) to (3), wherein a fiber length of the
cellulose fiber is 35 mm or more. [0016] (5) A face mask comprising
the nonwoven fabric for skin care products according to any one of
(1) to (4). [0017] (6) A cleansing sheet comprising the nonwoven
fabric for skin care products according to any one of (1) to
(4).
[0018] According to the present invention, the nonwoven fabric for
skin care products having excellent handleability as a skin care
product and having excellent adhesion to skin and having excellent
wipeability of cosmetic attached to skin as the skin care product
by forming the nonwoven fabric for skin care products, in which the
nonwoven fabric for skin care products includes the specific
thermoplastic resin fiber and the specific cellulose fiber and,
further, in which the total content of the thermoplastic resin
fiber and the cellulose fiber and the content ratio by mass of the
thermoplastic resin fiber to the cellulose fiber (Thermoplastic
resin fiber/Cellulose fiber) are in the specific ranges.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0019] Hereinafter, the embodiments of the nonwoven fabric for skin
care products according to the present invention will be described
in detail. The nonwoven fabric for skin care products according to
the present invention includes a thermoplastic resin fiber having a
single fiber diameter of 50 nm or more and 800 nm or less and a
cellulose fiber having a tensile strength of 1.9 cN/dtex or less
measured in accordance with JIS L 1015:2010 8.7.2. In addition, in
the nonwoven fabric for skin care products according to the present
invention, the nonwoven fabric for skin care products has a total
content of the thermoplastic resin fiber and the cellulose fiber of
85% by mass or more and a content ratio by mass of the
thermoplastic resin fiber to the cellulose fiber (Thermoplastic
resin fiber/Cellulose fiber) of 0.06 to 0.22. Hereinafter, the
tensile strength measured in accordance with JIS L 1015:2010 8.7.2
may be simply referred to as the tensile strength. The total
content of the thermoplastic resin fiber and the cellulose fiber
may be simply referred to as the total content. The content ratio
by mass of the thermoplastic resin fiber to the cellulose fiber
(Thermoplastic resin fiber/Cellulose fiber) may be simply referred
to as the content ratio by mass.
[0020] The nonwoven fabric for skin care products according to the
present invention exhibits excellent strength at the time of a wet
state and also exhibits an excellent coefficient of static
friction, followability, liquid retention property, and softness at
compression by employing the above-described constitution. The
detail of the mechanism in which the nonwoven fabric for skin care
products according to the present invention exhibits the
above-described effect is presumed as follows. Namely, as described
above, the nonwoven fabric for skin care products according to the
present invention includes the thermoplastic resin fiber having a
single fiber diameter of 50 nm or more and 800 nm or less, in which
the single fiber diameter is extremely thin and thus the
thermoplastic rein fiber has excellent softness, and among the
cellulose fibers that tend to have a high tensile strength, the
cellulose fiber having a tensile strength of 1.9 cN/dtex or less,
which provides adequate softness and an excellent water absorption
property. At the same time, a large part of the nonwoven fabric for
skin care products is constituted of the thermoplastic resin fiber
and the cellulose fiber having the total content of 85% by mass or
more. In addition, the content ratio by mass of the thermoplastic
resin fiber and the cellulose fiber is 0.06 to 0.22, that is, the
nonwoven fabric for skin care products has a specific content ratio
of two fibers having different properties as described above.
Consequently, the nonwoven fabric for skin care products according
to the present invention has adequate tensile strength at the time
of a wet state that provides excellent handleability of the skin
care products in which the nonwoven fabric for skin care products
is used and also has excellent softness at the time of a wet state
(that is, softness at compression), followability, and a liquid
retention property. These properties allow the skin care product
using the nonwoven fabric for skin care products according to the
present invention (hereinafter, may be referred to as the present
skin care product) to exhibit excellent followability to unevenness
existing on the surface of a user's skin (hereinafter, may be
simply referred to as the skin) and generation of a large gap
between the present skin care product and the skin to be reduced in
the time of use. Furthermore, the nonwoven fabric for skin care
products according to the present invention includes the
thermoplastic resin fiber, which is an extremely thin fiber, in a
specific amount. Therefore, the thermoplastic resin fiber existing
on the surface of the nonwoven fabric for skin care products goes
into small winkles existing on the skin at the time of use of the
present skin care product and thus the contact area of the nonwoven
fabric for skin care products and the skin becomes larger,
resulting in providing an excellent coefficient of static friction.
Thus, the present skin care product does not easily slip on the
skin. Therefore, it is presumed that the excellent adhesion and
excellent wipeability of the present skin care product are
exhibited by the excellent followability of the present skin care
product to the skin and the reduction in slippage between the
present skin care product and the skin.
[0021] In addition, the skin care product using the nonwoven fabric
for skin care products according to the present invention has not
only excellent adhesion with the skin immediately after the use of
the skin care product but also excellent adhesion with the skin at
a certain period of time after the use of the skin care product.
Whether the adhesion of the skin care product to the skin at a
certain period of time after the use is excellent can be evaluated
by the adhesion to the skin after 20 minutes of the use of the skin
care product (hereinafter, may be simply referred to as adhesion
after 20 minutes).
[0022] The nonwoven fabric for skin care products of the present
invention includes the thermoplastic resin fiber having a single
fiber diameter of 50 nm or more and 800 nm or less. First, this
thermoplastic resin fiber will be described.
[0023] The thermoplastic resin fiber used for the nonwoven fabric
for skin care products according to the present invention is a
fiber having a single fiber diameter of 50 nm or more and 800 nm or
less. The nonwoven fabric for skin care products including the
thermoplastic resin fiber determining the single fiber diameter of
the thermoplastic resin fiber to be 50 nm or more allows the
thermoplastic resin fiber to be prevented from falling off and
remaining on the skin when the skin care product using the nonwoven
fabric for skin care products is used. On the other hand, the
nonwoven fabric for skin care products including the thermoplastic
resin fiber determining the single fiber diameter of the
thermoplastic resin fiber to be 800 nm or less allows the contact
area of the surface of the nonwoven fabric for skin care products
with the skin to increase and the coefficient of friction between
the skin and the nonwoven fabric for skin care products to be
improved. Consequently, the nonwoven fabric is prevented from
slipping on the skin surface and thus the adhesion and wipeability
of the skin care product using this nonwoven fabric for skin care
products are excellent. From the above-described reasons, the upper
limit of the single fiber diameter of the thermoplastic resin fiber
is more preferably 500 nm or less and further preferably 300 nm or
less.
[0024] Examples of the thermoplastic resin included in the
thermoplastic resin fiber used in the present invention include
polyesters, polyamides, and polyolefins. Of these thermoplastic
resins, the thermoplastic resin fiber is preferably a polyamide
fiber from the viewpoint of improving the adhesion and wipeability
at the time of a wet state. Use of the polyamide fiber, which has a
water absorption property, as a thermoplastic resin fiber having a
single fiber diameter of 50 nm or more and 800 nm or less allows
the capillary effect of absorbing a facial lotion existing between
the nonwoven fabric for skin care products and the skin to be
improved and the nonwoven fabric for skin care products to absorb
the excess facial lotion between the nonwoven fabric and the skin.
Consequently, the contact area between the nonwoven fabric for skin
care products and the skin increases and, as a result, the adhesion
and wipeability at the time of a wet state can be further improved.
Here, in these thermoplastic resins, other components may be
polymerized or additives such as a stabilizer may be contained.
[0025] Here, as the polyamide, for example, nylon 6, nylon 11,
nylon 12, nylon 66, and various aramid resins can be used. Of these
polyamides, nylon 6 having an excellent water absorption property
is preferably used.
[0026] In the group of thermoplastic resin fibers included in the
present invention, each thermoplastic resin fiber may be dispersed
and present individually, at least a part of the thermoplastic
resin fiber is partially bonded to each other to be present, or at
least a part of the thermoplastic resin fiber may present by
agglomerating the thermoplastic resin fibers to form of a bundle.
Furthermore, the thermoplastic resin fiber is not particularly
limited in its length, cross-sectional shape, or the like and may
be in the form of what is called fiber-like shape.
[0027] In addition, the nonwoven fabric for skin care products
according to the present invention includes the cellulose fiber
having a tensile strength of 1.9 cN/dtex or less, which has
moderate softness. Hereinafter, this cellulose fiber will be
described.
[0028] The nonwoven fabric for skin care products at the time of a
wet state has high followability to the fine unevenness of the
skin. As a result, the tensile strength of the cellulose fiber is
preferably 1.7 cN/dtex or less and more preferably 1.5 cN/dtex or
less because the adhesion and the wipeability of the skin care
product using the nonwoven fabric for skin care products are more
improved. The lower limit of the tensile strength of the cellulose
fiber is not particularly limited and is preferably 0.9 cN/dtex or
more because the handleability of the present skin care product can
be more improved. In addition, the fiber length of a cellulose
fiber is preferably 35 mm or more. The cellulose fiber having a
fiber length of 35 mm or more allows the degree of entanglement
among the fibers in the nonwoven fabric for skin care products to
increase. The increase in the degree of entanglement among the
fibers in the nonwoven fabric for skin care products results in
increasing the strength of the nonwoven fabric for skin care
products at the time of a wet state. As a result, the handleability
of the present skin care product becomes more excellent. The upper
limit of the fiber length of the cellulose fiber is not
particularly limited and is preferably 80 mm or less from the
viewpoint that the process passability of the fiber in the
production process described below becomes more excellent.
[0029] As the cellulose fiber used in the present invention,
plant-based natural fibers such as pulp and cotton, regenerated
fibers such as rayon and cupra, and semi-synthetic fibers such as
acetate and triacetate can be used. Of these cellulose fibers,
rayon is preferable because the adhesion and wipeability of the
present skin care product can be more excellent.
[0030] In the nonwoven fabric for skin care products according to
the present invention, the total content of the thermoplastic resin
fiber and the cellulose fiber is 85% by mass or more relative to
the total mass of the nonwoven fabric for skin care products. It is
presumed that the nonwoven fabric for skin care products having a
total content of 85% by mass or more of the fibers allows the
bulkiness of the nonwoven fabric for skin care products at the time
of a wet state to increase and the softness of the nonwoven fabric
for skin care products to be improved and thus the present skin
care product has excellent adhesion and wipeability. From the
above-described reasons, the total content is preferably 95% by
mass or more and more preferably 100% by mass.
[0031] In the nonwoven fabric for skin care products according to
the present invention, the content ratio by mass of thermoplastic
resin fiber to cellulose fiber (Thermoplastic resin fiber/Cellulose
fiber) is 0.06 to 0.22. As described above, the nonwoven fabric for
skin care products having the content ratio by mass within the
above-described range has the excellent adhesion and wipeability of
the present skin care product. In addition, the content ratio by
mass is preferably 0.20 or less because the handleability of the
present skin care product can be more improved by increasing the
content of the cellulose fiber relative to the content of the
thermoplastic resin fiber as a reference.
[0032] Here, the softness in the present invention refers to
softness when the nonwoven fabric for skin care products according
to the present invention is compressed in the thickness direction
of the nonwoven fabric for skin care products (that is, softness at
compression). As a method of evaluating the above-described
softness, there is a WC value measured by a KES compression tester.
The above-described WC value is the amount of work (gfcm/cm.sup.2)
up to the maximum pressure when a fabric is compressed. As this
value becomes higher, the softness at compression becomes better.
The WC value measured by the KES compression test in the present
invention is a WC value measured at the time of a wet state and,
from the above-described reasons, the WC value of the nonwoven
fabric for skin care products is preferably 0.40 gfcm/cm.sup.2 or
more, more preferably 0.50 gfcm/cm.sup.2 or more, and further
preferably 0.60 gfcm/cm.sup.2 or more.
[0033] The nonwoven fabric for skin care products of the present
invention may be a nonwoven fabric for skin care products including
a thermoplastic resin fiber having a single fiber diameter of more
than 800 nm, a cellulose fiber having a tensile strength at the
time of a wet state of more than 1.9 cN/dtex, and fibers other than
the thermoplastic resin fiber and the cellulose fiber in the range
where the effect is not impaired. Examples of fibers other than the
thermoplastic resin fiber and the cellulose fiber include animal
natural fibers such as silk and wool. Furthermore, for example, in
the case where the thermoplastic resin fiber having a diameter of
more than 800 nm includes a polyethylene terephthalate fiber having
a single fiber fineness of 1.6 dtex or more (single fiber diameter
12.3 .mu.m), the cross-sectional shape of this fiber is preferably
an atypical cross section and more preferably a flat cross section.
It is presumed that the fiber having a cross-sectional shape of the
atypical cross section or the flat cross section has smaller second
moment of the fiber than that of the fiber having the circular
cross section and consequently the softness of the nonwoven fabric
for skin care products (that is, the softness at compression) and
followability at the time of a wet state are improved.
[0034] The basis weight of the nonwoven fabric for skin care
products according to the present invention is preferably 25
g/m.sup.2 to 150 g/m.sup.2 and the lower limit thereof is more
preferably 30 g/m.sup.2 or more, and further preferably 40
g/m.sup.2 or more. On the other hand, the upper limit thereof is
more preferably 100 g/m.sup.2 or less, and further preferably 70
g/m.sup.2 or less. The nonwoven fabric for skin care products
having a basis weight of 25 g/m.sup.2 or more allows the strength
of the nonwoven fabric for skin care products to be excellent. On
the other hand, the nonwoven fabric for skin care products having a
basis weight of 150 g/m.sup.2 or less allows the flexibility of the
nonwoven fabric to be improved. Here, the basis weight of the
nonwoven fabric for skin care products according to the present
invention can be measured in accordance with JIS L 1913:1998
6.2.
[0035] The nonwoven fabric for skin care products according to the
present invention includes a thermoplastic resin fiber having a
single fiber diameter of 50 nm or more and 800 nm or less. It is
presumed that the thermoplastic resin fiber goes into the fine
unevenness on the skin surface, whereby the contact area between
the skin and the nonwoven fabric for skin care products increases,
the coefficient of friction between the nonwoven fabric for skin
care products and the skin is improved, slip of the nonwoven fabric
for skin care products on the surface of the skin is reduced, and
consequently the thermoplastic resin fiber contributes to the
improvement of the adhesion and wipeability of the present skin
care product. Here, as a method for evaluating the coefficient of
friction between the nonwoven fabric for skin care products and the
skin, the coefficient of friction can be evaluated by the
coefficient of static friction when the nonwoven fabric for skin
care products is impregnated with a lotion in accordance with the
inclination method in JIS P 8147:1994 3.2. The coefficient of
static friction between the nonwoven fabric for skin care products
and the skin is preferably 0.5 or more and more preferably 0.6 or
more because the adhesion and wipeability of the present skin care
product becomes more excellent.
[0036] In addition, it is presumed that the nonwoven fabric for
skin care products according to the present invention includes the
cellulose fiber having a tensile strength of 1.9 cN/dtex or less,
whereby the nonwoven fabric for skin care products follows along
the fine unevenness of the skin at the time of a wet state to
improve the followability of the nonwoven fabric for skin care
products and consequently the cellulose fiber contributes to the
improvement of the adhesion and wipeability of the present skin
care product. In other words, the 20% elongation stress of the
nonwoven fabric for skin care products at the time of a wet state
is preferably 5.0 N/25 mm or less because the above-described
followability is sufficient for improving the adhesion and the like
of the present skin care product. From the above-described reasons,
the 20% elongation stress is more preferably 4.0 N/25 mm or less
and further preferably 3.0 N/25 mm or less. The elongation stress
of the nonwoven fabric for skin care products according to the
present invention at the time of a wet state can be measured by
reading out the stress when the nonwoven fabric for skin care
products is elongated at 20% of the initial length with a constant
speed elongation type tensile tester in accordance with JIS L
1913:1998 6.3.2. In addition, for example, appropriate adjustment
of the content and the single fiber fineness of the cellulose fiber
included in the nonwoven fabric for skin care products according to
the present invention allows 20% elongation stress of the nonwoven
fabric for skin care products at the time of a wet state to be
desired stress.
[0037] In addition, the nonwoven fabric for skin care products
according to the present invention preferably includes the
cellulose fiber, which has having excellent liquid retention
property, in a content of 70% by mass or more relative to the total
mass of the nonwoven fabric for skin care products. When the skin
care product is prepared by impregnating a facial lotion into the
nonwoven fabric for skin care products, such a constitution allows
the volatilization of the facial lotion into air to be reduced
because the cellulose fiber takes the facial lotion inside the
fiber. Consequently, the liquid retention property of the present
skin care product is improved. It is presumed that this liquid
retention property improvement contributes to improvement in the
adhesion (in particular, the adhesion after 20 minutes) and
wipeability of the present skin care product. As a method for
evaluating the above-described liquid retention property, the
liquid retention property can be evaluated by a facial lotion
retention ratio using the value of the initial amount of the lotion
that the nonwoven fabric for skin care products holds and the value
of the amount of the lotion that the nonwoven fabric for skin care
products holds after 20 minutes when the nonwoven fabric for skin
care products impregnated with the lotion is placed on pseudo-skin.
The facial lotion retention ratio after 20 minutes of the nonwoven
fabric for skin care products is preferably 75% or more, more
preferably 80% or more, and further preferably 85% or more because
the adhesion and the wipeability at the time of a wet state are
retained for a long period of time.
[0038] Here, the nonwoven fabric for skin care products according
to the present invention is preferably a dry nonwoven fabric. Use
of the dry nonwoven fabric allows the thickness of the nonwoven
fabric to be increased as compared with a wet nonwoven fabric, and,
as a result, the softness of the nonwoven fabric at compression can
be improved. Furthermore, among the dry nonwoven fabrics, the
nonwoven fabric for skin care products according to the present
invention is preferably a spunlace nonwoven fabric. The spunlace
nonwoven fabric can be obtained by a method in which constituent
fiber is entangled by high-pressure water flow. Compared with a
method in which a constituent fiber is entangled by needle punch,
this method provides the nonwoven fabric for skin care products
having low breakage of the constituent fiber at the time of
entanglement and having flexible feeling.
[0039] As a method for obtaining the thermoplastic resin fiber
according to the present invention, for example, the method
disclosed in WO 12/173116 pamphlet can be employed.
[0040] Skin care products such as face masks or skin care sheets,
eye masks, cleansing sheets, and cleansing sheets for point makeup
can be prepared from the nonwoven fabric for skin care products
according to the present invention by immersing the nonwoven fabric
for skin care products into a facial lotion such as a lotion, an
essence, or a cleansing agent.
EXAMPLES
[0041] The measuring method used in Examples will be described
below.
[0042] (1) Tensile Strength of Cellulose Fiber
[0043] The tensile strength of cellulose fiber was measured in
accordance with JIS L 1015:2010 8.7.2.
[0044] Specifically, 50 cellulose fibers were collected from the
nonwoven fabric for skin care products. Subsequently, each fiber
was immersed in water for 2 minutes and thereafter one of 50
cellulose fibers was attached to a constant speed elongation type
tensile tester to measure the tensile strength in water. This
measurement was carried out for 50 cellulose fibers. The clamping
distance was 20 mm. Load was applied at a tensile speed of 20
mm/min until the sample was cut and the strength at the time of the
cut was measured. The average value of the measurement results of
50 tensile strength measurements was calculated. The calculated
value was determined to be the tensile strength of the cellulose
fiber. In the case where the fiber was too short to test with a
clamping distance of 20 mm, load was applied until the sample was
cut at a tension speed of 10 mm/min with a clamping distance of 10
mm and the strength at the time of cut was measured.
[0045] (2) Fiber Length of Cellulose Fiber
[0046] The fiber length of the cellulose fiber was measured in
accordance with the direct method (Method C) in JIS L 1913:2010
8.4.1. Specifically, the nonwoven fabric for skin care products
having a size of 80 mm.times.80 mm was prepared as a sample. On one
side of the sample, a center point and a circle having a diameter
of 6 cm sharing the center point of this sample were drawn.
Subsequently, one cellulose fiber was randomly taken out at the
time from the inside of this circle. A total of 25 cellulose fibers
were collected. The same operation as this operation was also
carried out on the other side of this sample. The fiber lengths of
the total of 50 cellulose fibers obtained from this sample were
measured as follows.
[0047] One cellulose fiber taken out randomly was straightened
without elongation. Subsequently, the fiber length of the cellulose
fiber in the straightened state was measured to the mm unit on a
scale. This measurement was carried out for 50 cellulose fibers and
the average value of the measured values of 50 fibers was
calculated. The average value was determined to be the fiber
length.
[0048] (3) Basis Weight
[0049] The basis weight was measured in accordance with JIS L
1913:1998 6.2. Specifically, three 300 mm.times.300 mm test
specimens were collected from the sample of the nonwoven fabric for
skin care products using a steel ruler and a razor blade. The mass
of the test specimen in the standard state was measured and the
mass per unit area was determined by the following equation,
followed by calculating the average value.
ms=m/S
[0050] Here, ms: Mass per unit area (g/m.sup.2)
[0051] m: Average weight of test specimens (g)
[0052] S: Area of test specimen (m.sup.2).
[0053] (4) Coefficient of Static Friction
[0054] The coefficient of static frictidn was measured in
accordance with the inclination method in JIS P8147:1994 3.2.
Specifically, ten test specimens (nonwoven fabric for skin care
products) having a width of 30 mm and a length of 130 mm were
prepared. Subsequently, five test specimens out of these ten test
specimens were used to evaluate the coefficient of static friction
in the direction of the movement of a production apparatus for
nonwoven fabric for skin care products according to the present
invention and five test specimens out of these ten test specimens
were used to evaluate the coefficient of static friction
perpendicular to the direction of the movement of the production
apparatus for the nonwoven fabric for skin care products according
to the present invention. Specifically, for the evaluation in the
direction of the movement, the test specimen was immersed for 10
minutes in a lotion (manufactured by Ryohin Keikaku Co., Ltd.,
"Kesyousui/Binkanhadayou Sittori Taipu (Lotion/Moist Type for
Sensitive Skin)") and taken out. This test specimen was immediately
attached to the weight of a slip inclination angle measurement
device. On the other hand, a silicone pseudo-skin (manufactured by
Beurax Co., Ltd.) was attached to the slip inclination angle
measurement device. The weight attached with the test specimen was
placed on the pseudo-skin so that the measurement surface of the
specimen came into contact with the silicone pseudo-skin and the
direction of the movement of the test specimen and the slip
direction of the slip inclination angle measurement device were
matched. The inclination angle at the time of dropping the weight
under the condition of an inclination angle rate of less than
3.degree./second was read out. The tangent (tan .theta.) of the
inclination angle was determined to be the coefficient of static
friction. In addition, for the evaluation of the direction
perpendicular to the direction of the movement, the test specimen
was immersed for 10 minutes in a lotion (manufactured by Ryohin
Keikaku Co., Ltd., "Kesyousui/Binkanhadayou Sittori Taipu
(Lotion/Moist Type for Sensitive Skin)") and taken out. This test
specimen was immediately attached to the weight of a slip
inclination angle measurement device. On the other hand, a silicone
pseudo-skin (manufactured by Beurax Co., Ltd.) was attached to the
slip inclination angle measurement device. The weight attached with
the test specimen was placed on the pseudo-skin so that the
measurement surface of the specimen came into contact with the
silicone pseudo-skin and the direction perpendicular to the
direction of the movement of the test specimen and the slip
direction of the slip inclination angle measurement device were
matched. The inclination angle at the time of dropping the weight
under the condition of an inclination angle rate of less than
3.degree./second was read out. The tangent (tan .theta.) of the
inclination angle was determined to be the coefficient of static
friction. The average of the obtained coefficients of static
friction of the 10 test specimens was determined to be the
coefficient of static friction of the nonwoven fabric for skin care
products according to the present invention. In addition, in order
to prevent the fluctuation of the measurement value, the lotion
used in the measurement shall be within one month after opening and
the pseudo-skin used in the measurement shall be used 5 times or
more and 50 times or less.
[0055] (5) Followability (20% Elongation Stress)
[0056] The followability was measured in accordance with JIS L
1913:1998 6.3.2. Specifically, ten test specimens (nonwoven fabric
for skin care products) having a width of 25 mm and a length of 150
mm were prepared. Subsequently, five test specimens out of these
ten test specimens were used to evaluate the followability in the
direction of the movement of a production apparatus for nonwoven
fabric for skin care products according to the present invention
and five test specimens out of these ten test specimens were used
to evaluate the followability in the direction perpendicular to the
direction of the movement of the production apparatus for nonwoven
fabric for skin care products according to the present invention.
Specifically, for the evaluation in the direction of the movement,
the test specimen was immersed into distilled water at 20.degree.
C. for 10 minutes and taken out. This test specimen was immediately
attached to a constant speed elongation type tensile tester. Load
was applied under conditions of a clamping distance of 100 mm and a
tensile speed of 200 mm/min until the test specimen was cut. The
stress when the test specimen was elongated at 20 mm (N/25 mm) was
read out from a stress-strain curve and the read value was
determined to be 20% tensile stress. For the evaluation of the
direction perpendicular to the direction of the movement, the test
specimen was immersed into distilled water at 20.degree. C. for 10
minutes and taken out. This test specimen was immediately attached
to a constant speed elongation type tensile tester. Load was
applied under conditions of a clamping distance of 100 mm and a
tensile speed of 200 mm/min until the test specimen was cut. The
stress when the test specimen was elongated at 20 mm (N/25 mm) was
read out from a stress-strain curve and the read value was
determined to be 20% tensile stress. The lower value of the
obtained average values of the 20% elongation stress in both of the
directions was determined to be the 20% elongation stress of the
nonwoven fabric for skin care products.
[0057] (6) Liquid Retention Property (Mass Retention Rate of
Lotion)
[0058] Five test specimens (nonwoven fabric for skin care products)
having a width of 25 mm and a length of 25 mm were collected from a
sample in which humidity was conditioned under an atmosphere of a
temperature of 20.degree. C. and a humidity of 60% RH for 24 hours.
Subsequently, the mass (g) of this test specimen was measured. In
addition, the mass (g) of silicone pseudo-skin (manufactured by
Beurax Co., Ltd., size: diameter 50 mm) was measured. The test
specimen was placed on this silicone pseudo-skin and a lotion
(manufactured by Ryohin Keikaku Co., Ltd., "Kesyousui/Binkanhadayou
Sittori Taipu (Lotion/Moist Type for Sensitive Skin)") was dropped
onto this test specimen to give a test specimen containing the
lotion in a content of 700% by mass relative to the total mass of
the test specimen. The initial total mass (g) of the test specimen,
the silicone pseudo-skin, and the lotion was measured in this
state. Subsequently, the test specimen was placed in a constant
temperature and humidity chamber having a temperature of 20.degree.
C. and a humidity of 60% RH. After 20 minutes, the above-described
sample was taken out, the total mass (g) of the test specimen, the
silicone pseudo-skin, and the lotion after 20 minutes was measured
and the facial lotion retention ratio (%) was calculated in
accordance with the following formula. The measurement was carried
out for 5 test specimens and the average value was calculated.
Initial mass of lotion (g)=Initial total mass (g)-Mass of silicone
pseudo-skin (g)-Mass of test specimen (g)
Mass of lotion after 20 minutes (g)=Total mass after 20 minutes
(g)-Mass of silicone pseudo-skin (g)-Mass of test specimen (g)
Mass retention ratio of lotion (%)=Mass of lotion after 20 minutes
(g)/Initial mass of lotion (g).times.100.
[0059] (7) Softness at Compression
[0060] Five test specimens having a size of 60 mm.times.60 mm were
collected from the nonwoven fabric for skin care products. The test
specimen was immersed into distilled water for 10 minutes and taken
out. This test specimen was immediately attached to a KES
compression tester (manufactured by Kato Tech Co., Ltd., model:
KES-G5) and a WC value (the amount of work (gfcm/cm.sup.2) up to
the maximum pressure) during compressing the sample was measured
under conditions of a compression rate of 20 .mu.m/sec and a
maximum compression load of 4.9 kPa using a pressure plate having
an area of 2 cm.sup.2 (circle). The average value of the measured
WC values was calculated. The calculated value was determined to be
the softness at compression of the nonwoven fabric for skin care
products.
[0061] (8') Monitoring Evaluation
[0062] [Face Mask]
[0063] The nonwoven fabric for skin care products obtained by each
Example and Comparative Example was punched into a mask shape to
prepare nonwoven fabric for face masks. The nonwoven fabric for
face masks were immersed into a lotion (manufactured by Ryohin
Keikaku Co., Ltd., "Kesyousui/Binkanhadayou Sittori Taipu
(Lotion/Moist Type for Sensitive Skin)") to give face masks
containing 700% by mass of the lotion relative to the total mass of
the nonwoven fabric for face masks. Subsequently, the adhesion
immediately after wear, adhesion after wear for 20 minutes,
followability, difficulty in drying, softness at compression of the
face mask and handleability of the face mask were evaluated by 10
female evaluators. These properties were evaluated in 10 full marks
based on each person's absolute evaluation and evaluated by the
following criteria from the average score of 10 female evaluators
(the digits after the decimal point was rounded off). As the score
becomes higher, the performance of the face mask becomes better.
[0064] A: 9 points to 10 points [0065] B: 6 points to 8 points
[0066] C: 3 points to 5 points [0067] D: 0 point to 2 points.
[0068] [Cleansing Sheet]
[0069] The nonwoven fabric for skin care products obtained by each
Example and Comparative Example was cut into a rectangle having a
width of 70 mm and a length of 55 mm. This cut nonwoven fabric was
immersed into a cleansing agent (KOSE COSMEPORT Corp., "White
Cleansing Water") to give a cleansing sheet containing 700% by mass
of the cleansing agent relative to the total mass of the cut
nonwoven fabric. Subsequently, wipeability of this cleansing sheet
to a cosmetic (manufactured by Shiseido Company, Limited,
"BENEFIQUE THEOTY SMART LIQUID EYELINER" (registered trademark))
attached to an eye line and handleability of the nonwoven fabric
were evaluated by 10 female evaluators. These properties were
evaluated in 10 full marks based on each person's absolute
evaluation and evaluated by the following criteria from the average
score of 10 female evaluators (the digits after the decimal point
was rounded off). As the score becomes higher, the performance of
the cleansing sheet becomes better. [0070] A: 9 points to 10 points
[0071] B: 6 points to 8 points [0072] C: 3 points to 5 points
[0073] D: 0 point to 2 points.
[0074] (9) Comprehensive Evaluation
[0075] The comprehensive evaluation of the feeling of use of the
face mask and cleansing sheet made of the nonwoven fabric for skin
care products obtained in each Example and Comparative Example was
carried out by the 10 female evaluators carrying out the monitoring
evaluation of the above (8). The comprehensive evaluation was
evaluated in 10 full marks based on each person's absolute
evaluation and evaluated by the following criteria from the average
score of 10 female evaluators (the digits after the decimal point
was rounded off). As the point becomes higher, the performance of
the face mask and cleansing sheet becomes better. [0076] A: 9
points to 10 points [0077] B: 6 points to 8 points [0078] C: 3
points to 5 points [0079] D: 0 point to 2 points.
Example 1
[0080] Thermoplastic Resin Fiber
[0081] (Sea-Island Structure Composite Fiber)
[0082] Polyethylene terephthalate (PET, melt viscosity: 160 Pas)
serving as an island component and PET (copolymerized PET, melt
viscosity: 95 Pas) copolymerized with 8.0% by mole of sodium
5-sulfoisophthalate serving as a sea component were separately
melted at 290.degree. C. and thereafter weighed. Melt spinning was
carried out by flowing these polymers into a pack for spinning in
which the known compound spinneret (a compound spinneret having an
arrangement disclosed in FIG. 6(b) in WO 12/173116 pamphlet) was
incorporated and a distribution plate having 1,000 drilled
distribution holes for the island component per discharge hole was
used so that the composition ratio of the island component/sea
component was 50/50 and discharging the composite polymer flow from
discharge holes to give an unstretched fiber. The unstretched fiber
was stretched at a stretching speed of 800 m/min to give a
sea-island structure composite fiber having an island component
diameter of 230 nm and a structure of 150 dtex-15 filaments. The
obtained sea-island structure composite fiber exhibited excellent
properties of a strength of 3.6 cN/dtex and an elongation of
30%.
[0083] (Crimp and Cut Process)
[0084] The filament made of the sea-island structure composite
fiber was crimped (12 threads/25 mm) and thereafter cut into a
short fiber having a length of 51 mm.
[0085] [Nonwoven Fabric for Skin Care Products]
[0086] After 31% by mass of the above-described thermoplastic resin
fiber (island component diameter: 230 nm) and 69% by mass of a
rayon fiber (single fiber fineness: 1.4 dtex, strength at the time
of a wet state: 1.1 cN/dtex, and fiber length: 38 mm) were mixed
and opened by a carding machine, web was formed by a cross-lap
webber. The web was entangled by high pressure water flow under
conditions of a pressure of 10 MPa and a flow rate of 1.0 m/min and
dried at a drying temperature of 100.degree. C. using a pin tenter
to give a nonwoven fabric. The sea component was removed by
treating the nonwoven fabric with a 1% sodium hydroxide aqueous
solution under conditions of a temperature of 95.degree. C., a bath
ratio of 1:40, and a treatment time of 30 minutes to give 65
g/m.sup.2 of the nonwoven fabric including 15% by mass of the
thermoplastic resin fiber (single fiber diameter: 230 nm) and 85%
by mass of the rayon fiber (single fiber fineness: 1.4 dtex,
strength at the time of a wet state: 1.1 cN/dtex, and fiber length:
38 mm). This nonwoven fabric was determined to be the nonwoven
fabric for skin care products. Here, the content of the
thermoplastic resin fiber and the content of the rayon fiber
included in the above-described nonwoven fabric for skin care
products are the contents relative to the total mass of the
above-described nonwoven fabric for skin care products after
removing the sea component.
[0087] Furthermore, the obtained nonwoven fabric for skin care
products was punched into a mask shape to give face masks. Other
than the face mask, this nonwoven fabric for skin care products was
cut into a rectangle having a width of 70 mm and a length of 55 mm
to give cleansing sheets. The constitution and the properties of
the face mask and the cleansing sheet in this Example are listed in
Tables 1 and 2.
Example 2
[0088] [Thermoplastic Resin Fiber (A)]
[0089] (Polymer Alloy Fiber)
[0090] Nylon 6 (N6) (40% by mass) having a melt viscosity of 212
Pas (262.degree. C., shear rate: 121.6 sec.sup.-1) and a melting
point of 220.degree. C. and poly-L-lactic acid (60% by mass) having
a weight average molecular weight of 120,000, a melt viscosity of
30 Pas (240.degree. C., shear rate: 2,432 sec.sup.-1), a melting
point of 170.degree. C., and an optical purity of 99.5% or more
were separately weighed. These polymers are separately fed to a
twin-screw extruding kneader described below in detail and kneaded
at 220.degree. C. to give polymer alloy chips.
[0091] Screw configuration: Co-rotating fully intermeshing type,
double thread screw
[0092] Screw: Diameter 37 mm, effective length 1,670 mm, and
L/D=45.1
[0093] The kneading part length is 28% of the screw effective
length.
[0094] The kneading part is positioned on the discharge side from
1/3 of the screw effective length.
[0095] The screw has 3 back flow parts existing in the course of
the screw, and
[0096] Vent: Two vents.
[0097] The obtained polymer alloy chips were supplied to a
single-screw extrusion type melting apparatus serving as a spinning
machine for staple. Melt spinning was carried out at a melt
temperature of 235.degree. C., a spinning temperature of
235.degree. C. (spinneret surface temperature 220.degree. C.), and
a spinning speed of 1,200 m/min to give a polymer alloy fiber. The
polymer alloy fiber was combined as a yarn and thereafter the yarn
was subjected to steam stretching to give a tow made of the polymer
alloy fibers having a single fiber fineness of 3.0 dtex. The
obtained polymer alloy fiber exhibited excellent properties of
strength of 3.5 cN/dtex, elongation of 45%, and U % of 1.0%.
[0098] (Crimp and Cut Process)
[0099] The tow made of the polymer alloy fiber was crimped (12
threads/25 mm) and thereafter cut into a short fiber having a
length of 51 mm.
[0100] [Nonwoven Fabric for Skin Care Products]
[0101] After 31% by mass of the thermoplastic resin fiber (island
component diameter: 230 nm), 57% by mass of a rayon fiber (single
fiber fineness: 1.4 dtex, strength at the time of a wet state: 1.1
cN/dtex, and fiber length: 38 mm), and 12% by mass of a
polyethylene terephthalate (PET) fiber (single fiber fineness: 1.6
dtex) were mixed and opened with a carding machine, web was formed
with a cross-lap webber. This web was entangled with a high
pressure water stream at a pressure of 10 MPa and a speed of 1.0
m/min and dried using a pin tenter at a drying temperature of
100.degree. C. to give a nonwoven fabric. The nonwoven fabric was
treated with a 1% sodium hydroxide aqueous solution at a
temperature of 95.degree. C., a bath ratio of 1:40, and a treatment
time of 30 minutes to remove the sea component to give a nonwoven
fabric of 65 g/m.sup.2 including 15% by mass of the thermoplastic
resin fiber (single fiber diameter: 230 nm), 70% by mass of the
rayon fiber (single fiber fineness: 1.4 dtex, strength at the time
of a wet state: 1.1 cN/dtex, and fiber length: 38 mm), and 15% by
mass of the polyethylene terephthalate (PET) fiber (single fiber
fineness: 1.6 dtex). This nonwoven fabric was determined to be the
nonwoven fabric for skin care products. The content of the
thermoplastic resin fiber and the content of the rayon fiber and
the PET fiber included in the nonwoven fabric for skin care
products described above are relative to the total mass of the
nonwoven fabric for skin care products after removing the sea
component.
[0102] Furthermore, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Example are
listed in Tables 1 and 2.
Example 3
[0103] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 2 except that the PET fiber in Example 2 was
replaced by a flat multi-leaf cross section polyester fiber (single
fiber fineness: 1.7 dtex) made of PET.
[0104] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Example are
listed in Tables 1 and 2.
Example 4
[0105] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 1 except that nylon 6 (N6 melt viscosity: 190
Pas) was used as the island component of the sea-island structure
composite fiber in Example 1, the spinning temperature was changed
to 270.degree. C., and the island component diameter of the
sea-island structure composite fiber was changed to 700 nm.
[0106] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Example are
listed in Tables 1 and 2.
Example 5
[0107] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 4 except that the island component diameter of
the sea-island structure composite fiber in Example 4 was changed
to 300 nm.
[0108] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Example are
listed in Tables 1 and 2.
Example 6
[0109] After 31% by mass of the thermoplastic resin fiber (island
component diameter: 230 nm) in Example 2 and 69% by mass of a rayon
fiber (single fiber fineness: 1.8 dtex, strength at the time of a
wet state: 1.9 cN/dtex, and fiber length: 38 mm) were mixed and
opened by a carding machine, web was formed by a cross-lap webber.
The web was entangled by high pressure water flow under conditions
of a pressure of 10 MPa and a flow rate of 1.0 m/min and dried at a
drying temperature of 100.degree. C. using a pin tenter to give a
nonwoven fabric. The sea component was removed by treating the
nonwoven fabric with a 1% sodium hydroxide aqueous solution under
conditions of a temperature of 95.degree. C., a bath ratio of 1:40,
and a treatment time of 30 minutes to give a nonwoven fabric having
a basis weight of 65 g/m.sup.2 and including 15% by mass of the
thermoplastic resin fiber (single fiber diameter: 230 nm) and 85%
by mass of the rayon fiber (single fiber fineness: 1.8 dtex,
strength at the time of a wet state: 1.9 cN/dtex, and fiber length:
38 mm). This nonwoven fabric was determined to be the nonwoven
fabric for skin care products. Here, the content of the
thermoplastic resin fiber and the content of the rayon fiber
included in the above-described nonwoven fabric for skin care
products are the contents relative to the total mass of the
above-described nonwoven fabric for skin care products after
removing the sea component.
[0110] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Example are
listed in Tables 1 and 2.
Example 7
[0111] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 6 except that the rayon fiber (single fiber
fineness: 1.8 dtex, strength at the time of a wet state: 1.9
cN/dtex, and fiber length: 38 mm) used in Example 6 was replaced by
a rayon fiber (single fiber fineness: 1.6 dtex, strength at the
time of a wet state: 1.6 cN/dtex, and fiber length: 38 mm).
[0112] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Example are
listed in Tables 1 and 2.
Example 8
[0113] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 6 except that the rayon fiber (single fiber
fineness: 1.6 dtex, strength at the time of a wet state: 1.6
cN/dtex, and fiber length: 38 mm) used in Example 7 was replaced by
a rayon fiber (single fiber fineness: 1.4 dtex, strength at the
time of a wet state: 1.1 cN/dtex, and fiber length: 38 mm).
[0114] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Example are
listed in Tables 1 and 2.
Example 9
[0115] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 8 except that the rayon fiber (single fiber
fineness: 1.4 dtex, strength at the time of a wet state: 1.1
cN/dtex, and fiber length: 38 mm) used in Example 8 was replaced by
a rayon fiber (single fiber fineness: 1.4 dtex, strength at the
time of a wet state: 1.1 cN/dtex, and fiber length: 32 mm).
[0116] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Example are
listed in Tables 1 and 2.
Example 10
[0117] [Thermoplastic Resin Fiber (A)]
[0118] The tow made of the polymer alloy fiber used in Example 8
was cut to 1 mm and the sea component was removed by treating the
cut tow with a 1% sodium hydroxide aqueous solution under
conditions of a temperature of 95.degree. C., a bath ratio of 1:40,
and a treatment time of 30 minutes to give the short fiber of the
thermoplastic resin fiber (single fiber diameter: 230 nm).
[0119] [Nonwoven Fabric for Skin Care Products]
[0120] 15% by mass of the thermoplastic resin fiber (single fiber
diameter: 230 nm) and 85% by mass of a rayon fiber (single fiber
fineness: 1.4 dtex, strength at the time of a wet state: 1.1
cN/dtex, and fiber length: 15 mm) were mixed and stirred and
thereafter a paper-like product having a basis weight of 65
g/m.sup.2 was formed with a rectangular sheeting machine and
entangled by high pressure water flow by the same method as the
method in Example 1 to give a nonwoven fabric for skin care
products.
[0121] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Example are
listed in Tables 1 and 2.
Comparative Example 1
[0122] After 31% by mass of the thermoplastic resin fiber (island
component diameter: 230 nm) used in Example 2 and 69% by mass of a
polyethylene terephthalate (PET) fiber (single fiber fineness: 1.6
dtex) were mixed and opened with a carding machine, web was formed
with a cross-lap webber. The web was entangled by high pressure
water flow under conditions of a pressure of 10 MPa and a flow rate
of 1.0 m/min and dried at a drying temperature of 100.degree. C.
using a pin tenter to give a nonwoven fabric. The sea component was
removed by treating the nonwoven fabric with a 1% sodium hydroxide
aqueous solution under conditions of a temperature of 95.degree.
C., a bath ratio of 1:40, and a treatment time of 30 minutes to
give a nonwoven fabric having a basis weight of 65 g/m.sup.2 and
including 15% by mass of the thermoplastic resin fiber (single
fiber diameter: 230 nm) and 85% by mass of the polyethylene
terephthalate (PET) fiber (single fiber fineness: 1.6 dtex). This
nonwoven fabric was determined to be the nonwoven fabric for skin
care products. Here, the content of the thermoplastic resin fiber
and the content of the PET fiber included in the above-described
nonwoven fabric for skin care products are the contents relative to
the total mass of the above-described nonwoven fabric for skin care
products after removing the sea component.
[0123] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Comparative
Example are listed in Tables 3 and 4.
Comparative Example 2
[0124] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 8 except that the rayon fiber (single fiber
fineness: 1.4 dtex, strength at the time of a wet state: 1.1
cN/dtex, and fiber length: 38 mm) used in Example 8 was replaced by
a lyocell fiber (single fiber fineness: 1.4 dtex, strength at the
time of a wet state: 3.2 cN/dtex, and fiber length: 38 mm).
[0125] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Comparative
Example are listed in Tables 3 and 4.
Comparative Example 3
[0126] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 8 except that the rayon fiber (single fiber
fineness: 1.4 dtex, strength at the time of a wet state: 1.1
cN/dtex, and fiber length: 38 mm) used in Example 8 was replaced by
a lyocell fiber (single fiber fineness: 1.25 dtex, strength at the
time of a wet state: 2.4 cN/dtex, and fiber length: 38 mm).
[0127] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Comparative
Example are listed in Tables 3 and 4.
Comparative Example 4
[0128] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 2 except that the content of the rayon fiber
(single fiber fineness: 1.4 dtex, strength at the time of a wet
state: 1.1 cN/dtex, and fiber length: 38 mm) used in Example 2 was
changed to 65% by mass and the content of the PET fiber (single
fiber fineness: 1.6 dtex) used in Example 2 was changed to 20% by
mass.
[0129] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Comparative
Example are listed in Tables 3 and 4.
Comparative Example 5
[0130] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 8 except that the content of the thermoplastic
resin fiber (single fiber diameter: 230 nm) used in Example 8 was
changed to 20% by mass and the content of the rayon fiber (single
fiber fineness: 1.4 dtex, strength at the time of a wet state: 1.1
cN/dtex, and fiber length: 38 mm) used in Example 8 was changed to
80%.
[0131] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Comparative
Example are listed in Tables 3 and 4.
Comparative Example 6
[0132] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 8 except that, for the polymer alloy fiber used
in example 8, the mass ratio of nylon 6 was changed to 80% by mass
and the mass ratio of poly-L-lactic acid was changed to 20%, and
the island component diameter of the thermoplastic resin fiber was
change to 1,000 nm.
[0133] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Comparative
Example are listed in Tables 3 and 4.
Comparative Example 7
[0134] A nonwoven fabric for skin care products having a basis
weight of 65 g/m.sup.2 was obtained by the same method as the
method in Example 8 except that the content of the thermoplastic
resin fiber (single fiber diameter: 230 nm) used in Example 8 was
changed to 50% by mass and the content of the rayon fiber (single
fiber fineness: 1.4 dtex, strength at the time of a wet state: 1.1
cN/dtex, and fiber length: 38 mm) used in Example 8 was changed to
50%.
[0135] Subsequently, face masks and cleansing sheets were obtained
by the same method as the method in Example 1 using this nonwoven
fabric for skin care products. The constitutions and the properties
of the face masks and the cleansing sheets in this Comparative
Example are listed in Tables 3 and 4.
[0136] Here, the adhesion of the face mask and the wipeability of
the cleansing sheet in Comparative Example 1 were inferior to the
adhesion of the face mask and the wipeability of the cleansing
sheet in Example 8. The reason is presumed to be that the
coefficient of static friction, followability, liquid retention
property, and softness at compression of the nonwoven fabric for
skin care products (Nonwoven fabric 11) used for the face mask and
cleansing sheet in Comparative example 1 were inferior to the
coefficient of static friction, followability, liquid retention
property, and softness at compression of the nonwoven fabric for
skin care products (Nonwoven fabric 8) used for the face mask and
cleansing sheet in Example 8.
[0137] The adhesion of the face mask and the wipeability of the
cleansing sheet in Comparative Example 2 were inferior to the
adhesion of the face mask and the wipeability of the cleansing
sheet in Example 8. The reason is presumed to be that the
coefficient of static friction, followability, and softness at
compression of the nonwoven fabric for skin care products (Nonwoven
fabric 12) used for the face mask and cleansing sheet in
Comparative Example 2 were inferior to the coefficient of static
friction, followability, and softness at compression of Nonwoven
fabric 8.
[0138] The adhesion of the face mask and the wipeability of the
cleansing sheet in Comparative Example 3 were inferior to the
adhesion of the face mask and the wipeability of the cleansing
sheet in Example 8. The reason is presumed to be that the
coefficient of static friction, followability, and softness at
compression of the nonwoven fabric for skin care products (Nonwoven
fabric 13) used for the face mask and cleansing sheet in
Comparative Example 3 were inferior to the coefficient of static
friction, followability, and softness at compression of Nonwoven
fabric 8.
[0139] The adhesion of the face mask and the wipeability of the
cleansing sheet in Comparative Example 4 were inferior to the
adhesion of the face mask and the wipeability of the cleansing
sheet in Example 2. The reason is presumed to be that the
coefficient of static friction, followability, liquid retention
property, and softness at compression of the nonwoven fabric for
skin care products (Nonwoven fabric 14) used for the face mask and
cleansing sheet in Comparative Example 4 were inferior to the
coefficient of static friction, followability, liquid retention
property, and softness at compression of the nonwoven fabric for
skin care products (Nonwoven fabric 2) used for the face mask and
cleansing sheet in Example 2.
[0140] The wipeability of the cleansing sheet in Comparative
Example 5 was inferior to the wipeability of the cleansing sheet in
Example 8. The reason is presumed to be that the content of the
thermoplastic resin fiber included in the nonwoven fabric for skin
care products (Nonwoven fabric 15) used for the cleansing sheet in
Comparative Example 5 was higher than the content of the
thermoplastic resin fiber included in Nonwoven fabric 8.
[0141] The adhesion of the face mask and the wipeability of the
cleansing sheet in Comparative Example 6 were inferior to the
adhesion of the face mask and the wipeability of the cleansing
sheet in Example 4. The reason is presumed to be that the
coefficient of static friction of the nonwoven fabric for skin care
products (Nonwoven fabric 16) used for the face mask and cleansing
sheet in Comparative Example 6 was inferior to the coefficient of
static friction of the nonwoven fabric for skin care products
(Nonwoven fabric 4) used for the face mask and cleansing sheet in
Example 4.
[0142] The wipeability of the cleansing sheet in Comparative
Example 7 was inferior to the wipeability of the cleansing sheet in
Example 8. The reason is presumed to be that the content ratios by
mass of the thermoplastic resin fiber and the cellulose fiber
(Thermoplastic resin fiber/Cellulose fiber) (that is, A/B) in
Nonwoven fabric 8 and the nonwoven fabric for skin care products
(Nonwoven fabric 17) used for the cleansing sheet in Comparative
Example 7 are different. In other words, the reason is presumed to
be that the value of A/B in Nonwoven fabric 17 is remarkably larger
than the value of A/B in Nonwoven fabric 8.
[0143] Here, the adhesion of the face mask and the wipeability of
the cleansing sheet after 20 minutes in Example 3 were superior to
the adhesion of the face mask and the wipeability of the cleansing
sheet after 20 minutes in Example 2. The reason is presumed to be
that the cross-sectional shape of the PET fiber included in the
nonwoven fabric for skin care products (Nonwoven fabric 3) used for
the face mask and the cleansing sheet in Example 3 is the flat
multi-leaf cross section, whereas the cross-sectional shape of the
PET fiber included in Nonwoven fabric 2 is the circular cross
section and thus the coefficient of static friction, followability,
liquid retention property, and softness at compression of Nonwoven
fabric 3 are superior to the coefficient of static friction,
followability, liquid retention property, and softness at
compression of Nonwoven fabric 2.
[0144] The adhesion of the face mask and the wipeability of the
cleansing sheet after 20 minutes in Example 5 were superior to the
adhesion of the face mask and the wipeability of the cleansing
sheet after 20 minutes in Example 4. The reason is presumed to be
that the coefficient of static friction, followability, liquid
retention property, and softness at compression of the nonwoven
fabric for skin care products (Nonwoven fabric 5) used for the face
mask and cleansing sheet in Example 5 were superior to the
coefficient of static friction, followability, liquid retention
property, and softness at compression of Nonwoven fabric 4.
[0145] The wipeability of the cleansing sheet in Example 8 was
superior to the wipeability of the cleansing sheet in Example 6 or
Example 7. The reason is presumed to be that the coefficient of
static friction, followability, liquid retention property, and
softness at compression of Nonwoven fabric 8 are superior to the
coefficient of static friction, followability, liquid retention
property, and softness at compression of the nonwoven fabric for
skin care products (Nonwoven fabric 6) used for the cleansing sheet
in Example 6 or the nonwoven fabric for skin care products
(Nonwoven fabric 7) used for the cleansing sheet in Example 7.
[0146] The adhesion of the face mask and the wipeability of the
cleansing sheet after 20 minutes in Example 8 were superior to the
adhesion of the face mask and the wipeability of the cleansing
sheet after 20 minutes in Example 1. The reason is presumed to be
that the coefficient of static friction, followability, liquid
retention property, and softness at compression of Nonwoven fabric
8 are superior to the coefficient of static friction,
followability, liquid retention property, and softness at
compression of the nonwoven fabric for skin care products (Nonwoven
fabric 1) used for the face mask and cleansing sheet in Example
1.
[0147] The wipeability of the cleansing sheet in Example 8 was
superior to the wipeability of the cleansing sheet in Example 9.
The reason is presumed to be that the fiber length of the rayon
fiber included in Nonwoven fabric 8 is longer than the fiber length
of the rayon fiber included in the nonwoven fabric for skin care
products (Nonwoven fabric 9) used for the cleansing sheet in
Example 9 and thus a degree of entanglement of Nonwoven fabric 8 is
higher than that of the Nonwoven fabric 9, resulting in a higher
strength at the time of a wet state of Nonwoven fabric 8 than the
strength at the time of a wet state of Nonwoven fabric 9. The same
applies to the assumption in which the wipeability of the cleansing
sheet in Example 8 is superior to the wipeability of the cleansing
sheet in Example 10.
[0148] The softness at compression of the face mask in Example 8
was superior to the softness at compression of the face mask in
Example 10. The reason is presumed to be that Nonwoven fabric 8 is
a dry nonwoven fabric while Nonwoven fabric 10 is a wet nonwoven
fabric.
TABLE-US-00001 TABLE 1 Example Example Example Example Example
Example Example Example Example Example Unit 1 2 3 4 5 6 7 8 9 10
Nonwoven Thermoplastic Material -- PET N6 N6 N6 N6 N6 N6 N6 N6 N6
fabric resin fiber Single nm 230 230 230 700 300 230 230 230 230
230 constitution (A) fiber diameter Content % by 15 15 15 15 15 15
15 15 15 15 mass Cellulose Material -- Rayon Rayon Rayon Rayon
Rayon Rayon Rayon Rayon Rayon Rayon fiber (B) Single dtex 1.4 1.4
1.4 1.4 1.4 1.8 1.6 1.4 1.4 1.4 fiber fineness Tensile cN/dtex 1.1
1.1 1.1 1.1 1.1 1.9 1.6 1.1 1.1 1.1 strength Fiber mm 38 38 38 38
38 38 38 38 32 15 length Content % by 85 70 70 85 85 85 85 85 85 85
mass Other fiber Material -- -- PET PET -- -- -- -- -- -- -- Single
dtex -- 1.6 1.7 -- -- -- -- -- -- -- fiber fineness Content % by --
15 15 -- -- -- -- -- -- -- mass Content ratio by mass A/B 0.18 0.21
0.21 0.18 0.18 0.18 0.18 0.18 0.18 0.18 of A/B Basis weight
g/m.sup.2 65 65 65 65 65 65 65 65 65 65 PET: Polyethylene
terephthalate N6: Nylon 6
TABLE-US-00002 TABLE 2 Example Example Example Example Example
Example Example Example Example Example Unit 1 2 3 4 5 6 7 8 9 10
Physical Coefficient of static -- 0.5 0.5 0.6 0.5 0.6 0.6 0.6 0.6
0.6 0.6 property friction Followability (stress N/25 mm 3.4 4.2 3.8
3.5 3.1 3.7 3.2 2.9 2.8 2.8 at 20% elongation) Liquid retention %
83 77 78 78 83 82 82 88 85 83 property (Mass retention ratio of
lotion) Softness at compression gf cm/cm.sup.2 0.60 0.44 0.61 0.58
0.65 0.59 0.63 0.70 0.64 0.38 (WC value) Monitoring Adhesion
immediately -- A A A A A A A A A A evaluation after use Adhesion
after 20 -- B B A B A A A A A A minutes Followability A B B B A B B
A A A Difficulty in drying -- A B B B B A A A A A Softness at -- A
A A B A B A A A C compression Wipeability -- B B A B A B B A C C
Handleability -- A A A A A A A A C C Comprehensive -- A A A A A A A
A B B evaluation
TABLE-US-00003 TABLE 3 Comparative Comparative Comparative
Comparative Comparative Comparative Comparative Unit Example 1
Example 2 Example 3 Example 4 Example 5 Example 6 Example 7
Nonwoven Thermo- Material -- N6 N6 N6 N6 N6 N6 N6 fabric plastic
Single fiber nm 230 230 230 230 230 1,000 230 constitution resin
fiber diameter (A) Content % by 15 15 15 15 20 15 50 mass Cellulose
Material -- -- Lyocell Lyocell Rayon Rayon Rayon Rayon fiber (B)
Single fiber dtex -- 1.4 1.25 1.4 1.4 1.4 1.4 fineness Tensile cN/
-- 3.2 2.4 1.1 1.1 1.1 1.1 strength dtex Fiber mm -- 38 38 38 38 38
38 length Content % by -- 85 85 65 80 85 50 mass Other fiber
Material -- PET -- -- PET -- -- -- Single dtex 1.6 -- -- 1.6 -- --
-- fiber fineness Content % by 85 -- -- 20 -- -- -- mass Content
ratio by mass of A/B -- 0.18 0.18 0.23 0.25 0.18 1.00 A/B Basis
weight g/m.sup.2 65 65 65 65 65 65 65 PET: Polyethylene
terephthalate N6: Nylon 6
TABLE-US-00004 TABLE 4 Comparative Comparative Comparative
Comparative Comparative Comparative Comparative Example Example
Example Example Example Example Example Unit 1 2 3 4 5 6 7 Physical
Coefficient -- 0.3 0.4 0.4 0.4 0.6 0.4 0.8 property of static
friction Followability N/25 mm 6.7 5.6 5.1 5.8 2.7 4.1 1.6 (stress
at 20% elongation) Liquid retention % 68 76 75 73 85 75 87 property
(Mass retention ratio of lotion) Softness at gf cm/cm.sup.2 0.28
0.38 0.36 0.39 0.65 0.58 0.75 compression (WC value) Monitoring
Adhesion -- C B B B A B A evaluation immediately after use Adhesion
after -- D C C C A C A 20 minutes Followability -- D D C D A C A
Difficulty in -- D B B D A B A drying Softness at -- D C C C A B A
compression Wipeability -- D C C C D C D Handleability -- A A A A D
A D Comprehensive -- D D C D D C D evaluation
* * * * *