JP6208549B2 - Nonwoven fabric using cellulose fiber - Google Patents

Description

  The present invention relates to a non-woven fabric, particularly a cosmetic non-woven fabric, which has good design properties, is difficult to squeeze when wet, and is excellent in handleability and adhesion when worn into a face mask.

Conventionally, a cellulose fiber nonwoven fabric has been widely used as a face mask for beauty. For example, a regenerated cellulose continuous long-fiber nonwoven fabric in which a copper ammonia rayon stock solution is made into a web by the falling tension method, the fibers self-adhere at the time of the web formation, and then made into a nonwoven fabric by three-dimensional entanglement by high-pressure water flow treatment, The stability is good and the touch is excellent (for example, see Patent Document 1 below).
In addition, a cellulose fiber nonwoven fabric such as cotton, pulp, rayon, etc. has been developed that has a good design and strength characteristics in a nonwoven fabric having a stripe pattern (see, for example, Patent Document 2 below).

However, the development of face mask non-woven fabrics for beauty use, which has been increasing in recent years, has not been sufficiently developed and has the following problems.
(1) A thin nonwoven fabric generally has high anisotropy and is not good in handleability and form stability when a face mask is worn.
(2) A nonwoven fabric with good handleability has increased basis weight and fabric thickness, and cannot maintain thinness, transparency and flexibility.
(3) There are many impurities such as binders, and skin irritation cannot be denied.
(4) Regenerated cellulose fibers generally have low wet strength and increase elongation, so that dimensional stability tends to deteriorate.
(5) Conventional nonwoven fabrics combined with synthetic fibers such as cellulose fibers and polyester have high strength and improved handleability, but the functions important for face masks such as adhesion and liquid retention are reduced.

Japanese Patent No. 4471620 JP 2013-64226 A

  The problem to be solved by the present invention is to solve the above-mentioned problems, high in design, thin and difficult to squeeze when wet, and when processed into a face mask, the nonwoven fabric has excellent handling and adhesion when worn. Is to provide.

As a result of intensive studies in order to solve the above problems, the present inventor found that the ratio of the unentangled part to the entangled part (unentangled ratio) of the cellulose fiber nonwoven fabric is in a specific range, and the entangled part and the unentangled part There are multiple rows of parts along one direction of the nonwoven fabric, meandering, and the unentangled part has an independent space surrounded by the entangled part. It was difficult, and when it was processed into a face mask, it was found that it was excellent in handling and adhesion when worn, and the present invention was completed.
That is, the present invention has the following configuration.

(1) A non-woven fabric having an entangled part and an unentangled part made of cellulose fiber, and the following (A) and (B) :
(A) The entangled part is present in a plurality of rows along one direction of the nonwoven fabric, meandering, and the unentangled part has an independent space surrounded by the entangled part ;
(B) The area ratio of the unentangled part to the whole nonwoven fabric is 20% or more and 70 % or less ;
A nonwoven fabric having the following characteristics.
(2) The above-mentioned (1) , wherein the direction k in which the unentangled portions are arranged is not parallel to the direction (non-woven fabric length direction: MD direction) perpendicular to the direction in which the nonwoven fabric has extensibility (non-woven fabric width direction: CD direction ). The nonwoven fabric described in 1.
(3) a direction having a stretchable nonwoven fabric (width direction of the nonwoven fabric: CD direction) in a humidified state, elongation of 50% or less than 10% when applying a constant load of 50 gf / cm, The nonwoven fabric as described in said (1) or (2).
(4) non-woven (the width direction of the nonwoven fabric: CD direction) direction having a stretchable fabric in the Young's modulus of the wet state is less 50mPa least 5 mPa, the above (1) to any crab described (3) Non-woven fabric.
(5) basis weight of the nonwoven fabric is 20 g / m ² or more 60 g / m ² or less, the (1) to (4) non-woven fabric of any crab described.
(6) A face mask comprising the nonwoven fabric according to any one of (1) to (5) above.

  The nonwoven fabric of the present invention has good design properties, and even when it is thin, it is difficult to squeeze when wet, and when processed into a face mask, it is excellent in handleability and adhesion when worn.

It is a top view of the hydroentanglement pattern of the nonwoven fabric in Example 1. FIG. It is a top view of the hydroentanglement pattern of the nonwoven fabric in the comparative example 1.

Hereinafter, the present invention will be specifically described.
As the cellulose fiber constituting the nonwoven fabric of the present invention, regenerated cellulose fibers such as copper ammonia rayon, viscose rayon, tencel (lyocell) and polynosic, and natural cellulose fibers such as cotton, pulp and hemp are used, preferably regenerated cellulose. Fiber. This fiber may be either a continuous long fiber or a short fiber. However, the continuous long fiber is more excellent in lint-free property and liquid absorption than that of the short fiber. Moreover, in the cellulose fiber nonwoven fabric which provided the binder and surfactant, since a water absorption fall and elution of a component are anxious about a cellulose fiber nonwoven fabric of a binder, it is preferable.

  The fiber diameter of the cellulose fiber used in the present invention is preferably 4 μm or more and 12 μm or less. More preferably, they are 4 micrometers or more and 10 micrometers or less, More preferably, they are 4 micrometers or more and 6 micrometers or less. When the thickness is less than 4 μm, the fiber structure becomes too dense, the elongation at the time of wetness decreases, and becomes too stiff, for example, when processed into a face mask, the followability to the skin at the time of wearing decreases. End up. On the other hand, when larger than 12 micrometers, a fiber structure will become coarse, the elongation at the time of wetness will become excess, and handling will worsen.

The basis weight of the cellulose fiber nonwoven fabric of the present invention is preferably 20 g / m ² or more and 60 g / m ² or less. More preferably 25 g / m ² or more 55 g / m ² or less, further preferably 30 g / m ² or more 50 g / m ² or less. When the basis weight of the cellulose fiber nonwoven fabric is less than 20 g / m ² , the handleability is remarkably deteriorated because it is too thin, and is not practical. On the other hand, when the basis weight is larger than 60 g / m ² , the handleability is excellent, but the cloth thickness and rigidity increase, and the movement of the skin does not follow, and the face mask performance itself such as a feeling of wear is deteriorated.

  The thickness of the cellulose fiber nonwoven fabric of the present invention is preferably 0.20 mm or more and 0.50 mm or less. More preferably, they are 0.25 mm or more and 0.50 mm or less, More preferably, they are 0.25 mm or more and 0.35 mm or less. When the thickness of the cellulose fiber nonwoven fabric is less than 0.20 mm, the handleability is remarkably lowered because it is too thin. When it is larger than 0.50 mm, the handleability is excellent, but the strength when wet is increased and the feeling of wearing the face mask is lowered.

The density of the cellulose fiber nonwoven fabric of the present invention is preferably 0.25 g / m ³ or less. More preferably, it is 0.20 g / m ³ or less. When the density of the cellulose fiber nonwoven fabric is larger than 0.25, the feeling of wearing a face mask such as a feeling of adhesion when wet is lowered. Further, the density of the cellulose fiber nonwoven fabric of the present invention is preferably low, but practically it is preferably 0.15 g / m ³ or more.

  It is preferable that the area ratio with respect to the whole nonwoven fabric of the unentangled part of the cellulose fiber nonwoven fabric of this invention is 20% or more and 80% or less. More preferably, they are 40% or more and 80% or less, More preferably, they are 40% or more and 70% or less. When the area ratio of the unentangled portion of the cellulose fiber nonwoven fabric is less than 20%, the elongation when wet is high, and the handleability is significantly reduced. If it is greater than 80%, the handleability is excellent, but the strength when wet becomes excessive. For example, when it is processed into a face mask, the followability to the skin at the time of wearing is poor, and the feeling of wearing the face mask decreases.

  In addition, the entangled portions of the nonwoven fabric exist in multiple rows along one direction of the nonwoven fabric, meander, have a plurality of intersections with each other, and the unentangled portion has an independent space surrounded by the entangled portions. It is characterized by. The direction in which a series of unentangled portions are arranged in parallel to the direction (non-woven fabric length direction (machine direction): MD direction) perpendicular to the direction in which the non-woven fiber has extensibility (non-woven fabric width direction: CD direction). However, by leaving the unentangled part while the entangled part draws a wave curve in the bias direction, it is possible to keep the strength of the nonwoven fabric fiber in the direction having the extensibility.

  On the other hand, a normal nonwoven fabric having no unentangled portion is too stretched and has poor handleability. The unentangled part is surrounded by the entangled part and exists independently, so that it does not grow too much and is excellent in handleability. In addition, for example, the nonwoven fabric having a stripe pattern described in Patent Document 2 has an entangled portion and an unentangled portion separated from each other and parallel and continuous stripes. The tensile strength in the direction of having is weak.

  FIG. 1 is an example of a plan view of the hydroentanglement pattern of the nonwoven fabric of the present invention. In the figure, reference numeral 2 denotes an entangled portion, which is present in a plurality of rows, meanders with respect to the machine direction (MD direction) of the nonwoven fabric, and adjacent entangled portions intersect at an intersection 4. Therefore, the unentangled part 3 is an independent space surrounded by the entangled part 2. And the direction k in which a series of unentangled parts 3 are lined up is not parallel to the machine direction (MD direction: length direction) of the nonwoven fabric. Since the unentangled portions 3 are arranged in a certain direction that is not parallel to the machine direction of the nonwoven fabric, the nonwoven fabric of the present invention has excellent design properties. However, when the area ratio of the unentangled portion is less than 20%, the unentangled portion can be confirmed by image analysis using a microscope as described later, but cannot be confirmed as an independent space by the naked eye, and the design property is also inferior. .

The entanglement method of the nonwoven fabric of the present invention can be any known entanglement method without any limitation, and is not particularly limited, but hydroentanglement is preferable, for example, columnar flow is preferably used. When the columnar flow nozzles are arranged in a row, the nonwoven fabric of the present invention cannot be produced because the nonwoven fabric is formed at a constant interval while the entangled portion and the unentangled portion are separated from each other.
Multiple rows of nozzles are required to make the nonwoven fabric of the present invention. If there are too many rows, there will be almost no unentangled part, and if there are few rows, the ratio of unentangled portions will be high, but the effect when nozzle clogging will increase. On the other hand, the nozzle pitch is also an important factor. If the nozzle pitch is too wide, there will be too many unentangled parts, and if it is too narrow, there will be almost no unentangled parts. In the present invention, it is necessary to appropriately set the nozzle pitch and the number of nozzle rows. For example, the pitch is set to 8.0 mm to 15.0 mm in the MD direction, 2.0 mm to 4.0 mm pitch in the CD direction, and the nozzle rows are set to 2 rows to 4 rows. In FIG. 1, 1 is a nozzle header, and each nozzle header is composed of two nozzle rows 5 and 6. The interval between the nozzle rows 5 and 6 is the nozzle pitch in the MD direction, and nozzle holes 7 are provided in each nozzle row at a constant pitch in the CD direction. Each nozzle header reciprocates in the machine direction (MD direction) and the perpendicular direction (CD direction) to meander the entangled portion 2.

  The elongation at a constant load of 50 gf / cm of the cellulose fiber nonwoven fabric of the present invention is preferably 10% or more and 50% or less in a wet state in the direction in which the nonwoven fabric has extensibility. More preferably, they are 10% or more and 40% or less, More preferably, they are 10% or more and 35% or less. When the elongation of the cellulose fiber nonwoven fabric is less than 10%, the handleability is excellent. However, when processed into a face mask, for example, it is stiff at the time of wearing and has poor followability to the skin, so the feeling of wearing the face mask decreases. . When it is larger than 50%, the elongation at the time of wetting is high, and the confounding is insufficient and easy to unravel.

  The Young's modulus of the cellulose fiber nonwoven fabric of the present invention is preferably 5 mPa or more and 50 mPa or less in a wet state in the direction in which the nonwoven fabric has extensibility. More preferably, it is 10 mPa or more and 40 mPa or less, More preferably, it is 10 mPa or more and 30 mPa or less. When the Young's modulus of the cellulose fiber non-woven fabric is less than 5 mPa, the elongation at the time of wetness is high, and the handleability is remarkably lowered. When it is larger than 50 mPa, the handleability is excellent, but the wet strength becomes excessive. For example, when processed into a face mask, the followability to the skin at the time of wearing is poor, and the feeling of wearing the face mask is lowered.

  In the present invention, the cosmetic non-woven fabric is a non-woven fabric used as a base material for cosmetic bulk or alcohol impregnation, such as a non-woven fabric sheet for a cosmetic face mask, a non-woven fabric sheet for antiperspirant, a wet tissue, a wet wipe sheet such as a makeup remover, etc. Say.

EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited only to these Examples. The measurement method in the present invention is shown below.
(1) Fiber diameter (μm)
The cellulose fiber nonwoven fabric was observed at a magnification of 10,000 times using a scanning electron microscope and JSM-6380 manufactured by JEOL, and 50 fibers were selected and the fiber diameter was measured to obtain an average value.
(2) Weight per unit (g / m ² )
The 0.05 m ² or more of the area of the cellulosic fibrous nonwoven fabric, after drying to constant weight at 105 ° C., 20 ° C., allowed to stand in a thermostatic chamber of RH 65% 16 hours or more and the weight thereof was measured, the nonwoven m ² The weight per gram (g) was determined.

(3) Thickness (mm)
The cellulose fiber nonwoven fabric was measured with a load of 1.96 kPa in a thickness test in accordance with JIS-L1096.
(4) Density (g / cm ³ )
The thickness and basis weight of the cellulose fiber nonwoven fabric were measured 10 times, and the density was calculated by the following formula using the average thickness (mm) A and basis weight B (g / m ² ).
Density = (B / A) / 1000

(5) Area ratio of unentangled part to the whole nonwoven fabric (%)
From the image analysis using a microscope (10 times), the total area B (mm ² ) of the unentangled portion was measured in the nonwoven fabric area A (mm ² ) where 50 points of unentangled portions were included. From (mm ² ), the area ratio of the unentangled part was determined by the following formula.
Area ratio of unentangled part = (B / A) × 100

(6) Elongation under constant load of 50 gf / cm (%)
Evaluation was performed using a KES-FB1 tensile tester manufactured by Kato Tech Co., Ltd. A test piece of 20 cm × 20 cm is immersed in distilled water, and after 1 minute, it is lightly drawn to such an extent that it does not drip, and is stretched under a load of 50 gf / cm in a direction having the stretchability of the nonwoven fabric by a tensile tester. The degree was measured three times and obtained by averaging.

(7) Young's modulus (mPa)
In accordance with JIS L 1096, a test piece having a width of 5 cm and a length of 15 cm is gripped so as to have a grasping length of 10 cm, and a constant speed extension type tensile tester (trade name: Tensilon UCT-1t (manufactured by Orientec Co., Ltd.) ) Was used to stretch the nonwoven fabric in the direction having the extensibility of the nonwoven fabric under the condition that the tensile speed was 30 cm ± 3 cm / min, and the Young's modulus when the sample broke was measured.

(8) Wearing feeling Twenty test subjects performed sensory evaluation of wearing feeling of face mask. The evaluation method and the judgment criteria are as follows, and the average value of 20 people was used as the sensory evaluation value of the touch of the sample.
Evaluation method: The test nonwoven fabric of each material is cut into a face mask type, and a face mask type sample that has been folded into four in a dry state is impregnated with pure water to impregnate the amount of water absorption for each material. After leaving for 1 minute, the face mask type sample is developed and attached to the face. At this time, handleability, adhesion, flexibility and the like are evaluated. Evaluate the degree of adhesion by looking through a mirror in a state of standing for 5 minutes after installation.
Judgment criteria: Evaluated according to the judgment criteria described in Table 1 below based on the sensory test SD method (-3 points + 3 points) obtained from the joint research results of Shinshu University Graduate School and Asahi Kasei Fibers Corporation. did.

Example 1
Cotton linter (degree of polymerization 900-1000) was dissolved with a copper ammonia solution (cotton linter 10 wt%, ammonia 7 wt%, copper 3 wt%) to prepare a spinning dope. Using a spinneret with a stock solution discharge hole diameter of 0.6 mm and 45 pieces / cm ² , the discharge rate per hole is 0.09 cc / min. Thus, a cellulose continuous long fiber web was obtained. The obtained cellulose continuous long fiber web was regenerated with dilute sulfuric acid, and the regenerated cellulose continuous long fiber web obtained after washing with water on a 40-mesh conveyor net (support) had two rows and a row spacing of 8 mm. Then, using three nozzle headers (nozzle header spacing is 100 mm) having columnar flow nozzle holes with a pitch of 4 mm in the CD direction, hydroentanglement treatment was performed with a high-pressure water flow of 3 mPa, and the sheet was entangled. Drying with hot air was performed to obtain a regenerated cellulose continuous long fiber nonwoven fabric having hydroentangled portions and unentangled portions formed on the surface. The entangled portion was meandered by reciprocating the nozzle header at right angles to the web traveling direction.

The obtained regenerated cellulose continuous long-fiber nonwoven fabric had a basis weight of 40.0 g / m ² , a thickness of 0.25 mm, and an area ratio of the unentangled portion to the entire nonwoven fabric was 49.3%. The top view of the obtained nonwoven fabric is shown in FIG. 1, and the evaluation results of characteristics and functionality are shown in Tables 2 and 3. As can be seen from Table 2 and Table 3, the obtained regenerated cellulose continuous long fiber non-woven fabric is easy to handle at the time of wearing when processed into a face mask and has good adhesion to the skin, and various uses for cosmetics. As the nonwoven fabric used for the above, it was a very good nonwoven fabric.

(Example 2)
Using recycled cellulose fiber nonwoven fabric (100% rayon fiber), on the 40 mesh conveyor net (support) under the same conditions as in Example 1, the number of rows is 2, the spacing between rows is 8 mm, in the CD direction. Using three nozzle headers (nozzle header spacing is 100 mm) with 4 mm pitch columnar flow nozzle holes, hydroentanglement treatment is performed with a high pressure water flow of 3 mPa, and the sheet is entangled, followed by hot air drying at 100 ° C. It was.
The obtained regenerated cellulose continuous long-fiber nonwoven fabric had a basis weight of 38.4 g / m ² , a thickness of 0.27 mm, and an area ratio of the unentangled portion to the entire nonwoven fabric of 53.2%. The evaluation results of characteristics and functionality are shown in Table 2 and Table 3. As can be seen from Table 2 and Table 3, the obtained regenerated cellulose fiber nonwoven fabric is easy to handle at the time of wearing when processed into a face mask and has good adhesion to the skin, and is used for various cosmetic applications. It was a very good nonwoven fabric.

(Example 3)
Example 1 except that a spinneret having a stock solution discharge hole diameter of 0.3 mm and 180 pieces / cm ² was used, the discharge amount per hole was 0.02 cc / min, and the interval between rows in the entanglement process was 15 mm. Under the same conditions, a regenerated cellulose continuous long fiber nonwoven fabric having a five-layer structure was obtained. The obtained regenerated cellulose continuous long-fiber nonwoven fabric had a basis weight of 29.6 g / m ² , a thickness of 0.28 mm, and an area ratio of the unentangled portion to the entire nonwoven fabric was 61.6%. The evaluation results of characteristics and functionality are shown in Table 2 and Table 3. As can be seen from Table 2 and Table 3, the obtained regenerated cellulose continuous long fiber non-woven fabric is easy to handle at the time of wearing when processed into a face mask and has good adhesion to the skin, and various uses for cosmetics. As the nonwoven fabric used for the above, it was a very good nonwoven fabric.

(Comparative Example 1)
In Example 1, the number of holes in the spinneret is 1300 / cm ² , the number of rows in the entanglement process is 7 rows, the row spacing is 0.4 mm, the nozzle hole pitch in the CD direction is 2.5 mm, and the hole diameter is 0. A regenerated cellulose continuous long-fiber nonwoven fabric having a five-layer structure was obtained under the same conditions as in Example 1 except that the thickness was 15 mm. The obtained regenerated cellulose continuous long-fiber nonwoven fabric had a basis weight of 40.0 g / m ² , a thickness of 0.30 mm, and an area ratio of the unentangled portion to the entire nonwoven fabric was 19.0%. The top view of the obtained nonwoven fabric is shown in FIG. 1, and the evaluation results of characteristics and functionality are shown in Tables 2 and 3. As can be seen from Tables 2 and 3, the obtained regenerated cellulose continuous long-fiber nonwoven fabric has high elongation when wet, remarkably lower handleability, and poor wearing feeling when worn into a face mask. Compared to the nonwoven fabric of the present invention, there are problems in using it for various purposes. In addition, with the naked eye, the unentangled part could not be confirmed as an independent space, and the design was inferior.

(Comparative Example 2)
Using the commercially available cellulose fiber nonwoven fabric (manufactured by Sanwa Paper Industry Co., Ltd., lyocell / pulp composite fiber), the same entanglement treatment as in Comparative Example 1 was performed. The basis weight of the obtained cellulose fiber nonwoven fabric was 34.5 g / m ² , the thickness was 0.38 mm, and the area ratio of the unentangled portion to the whole nonwoven fabric was 19.9%. The evaluation results of characteristics and functionality are shown in Table 2 and Table 3.

(Comparative Example 3)
In accordance with the description in Example 2 of Patent Document 2, a part of the fiber web in which the constituent fibers are entangled with cellulose and synthetic fiber composite nonwoven fabric (manufactured by Daiwabo Holdings Co., Ltd., pulp / polyester composite fiber) is entangled. A spunlace nonwoven fabric was obtained which was rearranged and the width of the stripes spaced apart from each other was 5 mm. The basis weight of the obtained nonwoven fabric was 40.2 g / m ² , the thickness was 0.39 mm, and the area ratio of the unentangled portion to the whole nonwoven fabric was 82.3%. The evaluation results of characteristics and functionality are shown in Table 2 and Table 3.

  The nonwoven fabric of the present invention is suitably used in the cosmetics field as a cosmetic bulk or base material for alcohol impregnation, such as a non-woven fabric sheet for a cosmetic face mask, a non-woven fabric sheet for antiperspirant, an alcohol wet tissue, a wet wipe sheet such as makeup remover.

DESCRIPTION OF SYMBOLS 1 Nozzle header 2 Interlaced part 3 Unentangled part 4 Intersection point 5 Nozzle row 6 Nozzle row 7 Nozzle hole

Claims (6)

A non-woven fabric having an entangled portion and an unentangled portion made of cellulose fiber, and the following (A) and (B) :
(A) The entangled part is present in a plurality of rows along one direction of the nonwoven fabric, meandering, and the unentangled part has an independent space surrounded by the entangled part ;
(B) The area ratio of the unentangled part to the whole nonwoven fabric is 20% or more and 70 % or less ;
A nonwoven fabric having the following characteristics. Direction k of arrangement of non-interlaced parts (the width direction of the nonwoven fabric: CD direction) direction with extensible non-woven perpendicular to the direction (non-woven fabric in the length direction: MD direction) and non-parallel, non-woven fabric of claim 1 . Nonwoven (width direction of the nonwoven fabric: CD direction) direction having a stretchable fabric in, in the wet state is 50% or less elongation of 10% or more when subjected to a constant load of 50 gf / cm, according to claim 1 Or the nonwoven fabric of 2. Nonwoven (width direction of the nonwoven fabric: CD direction) direction having a stretchable fabric in the Young's modulus of the wet state is less 50mPa least 5 mPa, nonwoven fabric according to claim 1. Basis weight of the nonwoven fabric is 20 g / m ² or more 60 g / m ² or less, the nonwoven fabric according to any one of claims 1-4. The face mask containing the nonwoven fabric as described in any one of Claims 1-5.