JP7448380B2 - Wet sheet and method for manufacturing the wet sheet - Google Patents

Description

The present invention relates to a wet sheet and a method for manufacturing the wet sheet.

It is known that a wet sheet in which a sheet base material is impregnated with an emulsion-based chemical solution containing an oil agent has excellent moisturizing performance (see, for example, Patent Document 1).

Japanese Patent Application Publication No. 2019-178094

However, there has been a demand for wet sheets that have even better moisturizing performance than wet sheets impregnated with emulsion-based chemicals.

An object of the present invention is to provide a wet sheet with excellent moisturizing performance and a method for manufacturing the wet sheet.

In order to solve the above problem, the invention according to claim 1,
A wet sheet in which a base sheet is impregnated with a chemical solution,
The chemical solution contains shea butter as an oil agent, PEG-20 glyceryl triisostearate as an emulsifier, and PEG-8 (caprylic acid/capric acid) glyceride ,
The base sheet is coated with cellulose nanofibers.

The invention according to claim 2 is the wet sheet according to claim 1,
The chemical liquid is characterized in that the oil agent is blended in an amount of 0.001% by mass to 0.100% by mass.

The invention according to claim 3 is the wet sheet according to claim 1 or 2,
The chemical liquid is impregnated in an amount of 200% to 500% by mass based on the dry weight of the base sheet.

The invention according to claim 4 is the wet sheet according to any one of claims 1 to 3,
The cellulose nanofiber is coated on the base sheet in an amount of 0.1 g/m ² to 10.0 g/m ² .

The invention according to claim 5 is a method for manufacturing a wet sheet, comprising:
a coating process of applying a cellulose nanofiber solution to a base sheet;
a heat drying step of heat drying the base sheet;
A chemical liquid impregnation step of impregnating the base sheet with a chemical liquid containing shea butter as an oil agent, PEG-20 glyceryl triisostearate as an emulsifier, and PEG-8 (caprylic acid/capric acid) glycerides. shall be.

According to the present invention, it is possible to provide a wet sheet with excellent moisturizing performance and a method for manufacturing the wet sheet.

FIG. 2 is a plan view showing a wet sheet with a herringbone pattern. FIG. 2 is a plan view showing a striped wet sheet. FIG. 2 is a plan view showing a wet sheet with a checkered pattern. FIG. 2 is a plan view showing a wet sheet with a mesh pattern. FIG. 2 is a plan view showing a wet sheet with a curved pattern. FIG. 6 is a sectional view taken along VI-VI in FIGS. 1 to 5. FIG.

Embodiments of the present invention will be described below with reference to the drawings. However, the scope of the invention is not limited to the illustrated example.

[Wet sheet]
FIG. 1 is a plan view showing a wet sheet S according to the present embodiment.
The wet sheet S has cellulose nanofibers (hereinafter referred to as CNF) in an amount of 0.1 g/m ² to 10.0 g/m ² , preferably 0.2 g/m ² to 5.0g/ ^m2 coating and impregnated with an emulsion-based chemical solution made by adding various ingredients to purified water, such as cleaning sheets used for baby wipes, adult body or baby wipes, etc. It is. When the amount of CNF applied is 0.1 g/m ² to 10.0 g/m ² , a wet sheet S with excellent moisture retention can be realized.
In addition, this wet sheet S, in the form of a product, can be stored in packaging means such as an airtight container having a sheet outlet that can be sealed with an openable lid.
When using the wet sheet S, put the wet sheet S directly into a container or bag, or put the bag containing the wet sheet S directly into the container, then open the outlet and remove the sheet inside. Pull it out and use it.

[Base material sheet]
The base sheet 10 is a nonwoven fabric manufactured using predetermined fibers as a fiber material, for example, by known techniques such as spunlace, air through, airlaid, point bond, spunbond, and needle punch. Examples of the prescribed fibers include cellulose fibers such as rayon, Lyocell, Tencel, and cotton; polyolefin fibers such as polyethylene, polypropylene, and polyvinyl alcohol; polyester fibers such as polyethylene terephthalate and polybutylene terephthalate; and polyamide fibers such as nylon. can be mentioned. These can be used alone or in combination of two or more, but it is preferable that cotton is blended in an amount of 1% to 10% by mass. can be made to be less irritating to the skin.

Note that the wet sheet S may be formed by plying (laminating) a plurality of base sheets 10 or may be formed from a single base sheet 10. If the wet sheet S has a multilayer structure, the chemical solution retention can be improved if the inner layer contains 6% to 10% cotton and the outer layer contains 0 to 4% cotton. If the amount is 6% to 10%, the user will feel more hydrated. Note that the content ratio of cotton in the inner layer and the outer layer is not limited to the above, and may be contained in each layer at a uniform ratio.

For example, as shown in FIG. 1, this base sheet 10 has a convex portion consisting of a high fiber density region 11 and a concave portion consisting of a low fiber density region 12. A predetermined pattern is formed by alternately arranging the fiber density regions 12.
Examples of the predetermined pattern include, as shown in FIG. 1, a herringbone pattern in which continuous V-shaped portions are formed by lines that are bent in opposite directions at predetermined intervals.

In the present invention, the angle of the V-shaped part of the herringbone pattern (the angle at which the line bends) is not particularly limited, but by setting it to, for example, 5° to 60°, the diffusivity and liquid permeability of the drug solution can be maximized. It can be made good.
Further, as the pattern formed on the base sheet 10, in addition to the herringbone pattern, for example, a striped pattern, a lattice pattern, a mesh pattern, a curved pattern, etc. can also be used. 2 to 5 show the base sheet 10 on which a striped pattern (FIG. 2), a checkered pattern (FIG. 3), a mesh pattern (FIG. 4), and a curved pattern (FIG. 5) are formed, respectively.

Note that in FIGS. 1 to 5, the high fiber density region 11 is shaded for convenience of explanation.
In addition, the "high fiber density region 11" as used herein means a region having a higher fiber density than the low fiber density region 12, and the density is not particularly limited as long as it is higher than the low fiber density region 12. .
Moreover, the "low fiber density region 12" means a region having a lower fiber density than the high fiber density region 11, and the density is not particularly limited as long as it is lower than the high fiber density region 11.

Since the base sheet 10 has the high fiber density region 11 and the low fiber density region 12, the area of contact with the skin is reduced, and the friction against the skin can be reduced. As a result, irritation to the skin can be reduced, so that the wet sheet S of the present invention can be used even by people with sensitive skin, infants, and the like.
In addition, by having the linear recesses (low fiber density regions 12), liquid diffusivity and liquid permeability are superior compared to a flat base sheet, so that the chemical solution is evenly and uniformly applied to the base sheet 10. It will be applied.

The number of lines in each pattern formed by the high fiber density area 11 and the low fiber density area 12 is preferably 3/cm to 7/cm.
Here, the number of lines (lines/cm) in this specification means how many linear high fiber density regions 11 and linear low fiber density regions 12 are present per 1 cm. There is.
In other words, it means how many fibers are present in the direction perpendicular to the direction parallel to the linear high fiber density region 11 and the linear low fiber density region 12 provided in parallel (the direction in which the number is greatest). are doing. In other words, 4 fibers/cm means that two linear high fiber density regions 11 and two low fiber density regions 12 are provided in 1 cm.
When the number of lines is less than 3 lines/cm, the surface of the base sheet 10 approaches a flat surface, making it easier for dirt once captured to transfer. Moreover, if the number of lines exceeds 7 lines/cm, the volume of the space formed by the high fiber density area 11 and the low fiber density area 12 becomes too small, so that a desired amount of dirt is applied to the low fiber density area 12. It becomes impossible to secure.

FIG. 6 is a cross-sectional view of the portion VI-VI in FIGS. 1 to 5.
The height (thickness) Hm of the high fiber density region 11 from the back surface is preferably, for example, 200 μm or more and less than 600 μm, and the height (thickness) Hd of the low fiber density region 12 from the back surface is, for example, 150 μm or more. , preferably less than 200 μm.
At this time, the height difference between the high fiber density region 11 and the low fiber density region 12 is preferably about 50 μm to 100 μm.
If the height difference is less than 50 μm, it is not possible to expect much of the trapping effect by the low fiber density region 12, making it impossible to secure the desired amount of wiping. This is because the thickness increases and the flexibility and texture are impaired.

Further, the fiber basis weight of the high fiber density region 11 is preferably about 40 g/m ² to 60 g/m ² , and the fiber basis weight of the low fiber density region 12 is, for example, 10 g/m ^{2 to 20 g/m 2} . It is preferable that it is about ² .
When the fiber basis weight satisfies the above range, a suitable thickness can be obtained, and the base sheet 10 can ensure both strength and flexibility.

Note that in this embodiment, the convex portion is the high fiber density region 11 and the concave portion is the low fiber density region 12, but the present invention is not limited to this. It may be the fiber density region 11. Further, it is preferable that the base sheet 10 has convex portions that are high fiber density regions 11 and concave portions that are low fiber density regions 12, but the present invention is not limited to this, and there is no need to provide a difference in fiber density. I don't mind.
Further, the area ratio of the high fiber density region 11 to the low fiber density region 12 in the base sheet 10 does not have to be 5:5, but is preferably within the range of 2:8 to 8:2. If one side is provided more than four times as many times as the other side, it is not preferable because it becomes difficult to feel the unevenness.

[CNF]
CNF is a material that retains moisture, is highly safe, and its aqueous solution has thixotropic properties. It is a fine cellulose fiber obtained by defibrating pulp fibers, and is generally used as a fiber. It refers to cellulose fibers including cellulose fine fibers with a nano-sized width (1 nm or more and 1000 nm or less), and preferably fine fibers with an average fiber width of 100 nm or less. The average fiber width is calculated using, for example, a number average of a certain number, a median, a mode diameter (most frequent value), or the like.

(Pulp fiber that can be used for CNF)
Pulp fibers that can be used as CNF include, for example, chemical pulps such as hardwood pulp (LBKP) and softwood pulp (NBKP), bleached thermomechanical pulp (BTMP), stone ground pulp (SGP), and pressed stone ground pulp (PGW). ), Refiner Ground Pulp (RGP), Chemi Grand Pulp (CGP), Thermo Grand Pulp (TGP), Ground Pulp (GP), Thermo Mechanical Pulp (TMP), Chemi Thermo Mechanical Pulp (CTMP), Refiner Mechanical Pulp (RMP) Waste paper manufactured from mechanical pulp such as tea paper, kraft envelope waste paper, magazine waste paper, newspaper waste paper, leaflet waste paper, office waste paper, cardboard waste paper, white paper waste paper, Kent waste paper, imitation waste paper, land certificate waste paper, recycled paper waste paper, etc. Examples include deinked pulp (DIP) obtained by deinking pulp and waste paper pulp. These may be used alone or in combination of two or more types, as long as they do not impair the effects of the present invention.

(Defibration method)
Defibration methods used in the production of CNF include, for example, mechanical methods such as high-pressure homogenizer method, microfluidizer method, grinder milling method, bead mill freeze-pulverization method, and ultrasonic defibration method. It is not limited to.

Note that CNF that has been subjected to only mechanical treatment (not modified) by the above-mentioned defibration method, that is, CNF that has not been modified with functional groups, is different from that modified with functional groups such as phosphate groups and carboxymethyl groups. Since it has high thermal stability, it can be used in a wider range of applications, but it is also possible to use CNF modified with functional groups such as phosphoric acid groups and carboxymethyl groups in the present invention.
Further, for example, pulp fibers subjected to mechanical defibration treatment may be subjected to chemical treatment such as carboxymethylation, or enzyme treatment. Examples of chemically treated CNF include iCNF (individualized CNF) (single nanocellulose) with a diameter of 3 nm to 4 nm, such as TEMPO-oxidized CNF, phosphate-esterified CNF, and phosphite-esterified CNF. It will be done.
Further, CNF that has been subjected to only chemical treatment or enzyme treatment, or CNF that has been subjected to chemical treatment or enzyme treatment and mechanical defibration treatment may be used.

[CMC]
In addition, in order to prevent aggregation of CNF in a solution, carboxymethyl cellulose (hereinafter referred to as CMC), which is a water-soluble polymer, may be added.
When CNF is added to an aqueous solvent, the microfibril fibers of CNF bond with each other and aggregate, but by adding CMC and making CNF and CMC coexist, the OH groups of CNF and OH groups of CMC are combined. are hydrogen-bonded, and the electrostatic interaction of the molecular chains and the steric hindrance effect prevent CNF from aggregating, allowing CNF to be uniformly dispersed in the solution.

CMC is preferably used because it is an extremely environmentally friendly material, as it is obtained using cellulose as a raw material, has mild biodegradability, and can be disposed of by incineration after use. Water-soluble polymers other than CMC may be used as long as they can prevent aggregation in the solution.
In addition, when adding CMC, when the entire solution is 100.000 mass%, purified water is 93.000 mass% to 99.790 mass%, CNF is 0.002 mass% to 0.020 mass%. % and CMC in a proportion of 0.100% by mass to 1.000% by mass.
In addition, when applying only CNF without adding CMC, it contains purified water in a proportion of 98.000% by mass to 99.500% by mass and CNF in a proportion of 0.500% by mass to 2.000% by mass. Preferably.

[Medicinal solution]
The drug solution is based on an emulsion, whose main component is water (purified water), and an oil agent and an emulsifier are mixed in a ratio of 1:4 to 1:19 to emulsify the solution.
With this configuration, the medicinal solution of this embodiment contains oil, so it is easy to remove stool and sebum stains that contain a large amount of oil. Therefore, the wet sheet S impregnated with the chemical solution of the present embodiment can thoroughly wipe away dirt with a small number of wet sheets S, and consumers can reduce the amount of wet sheets S they purchase.
In addition, especially when the oil agent and emulsifier are blended in such a ratio, the emulsion stability of the solution is improved, water and oil agent are solubilized, and the solution becomes translucent or transparent, so it is possible to check the presence or absence of impurities in the chemical solution. , quality control such as pH measurement becomes easier, and operability can be improved.
If the ratio of the emulsifier to the oil agent is lower than the above, it is not desirable because the solution becomes difficult to emulsify or the emulsion becomes difficult to become translucent or transparent. Furthermore, even if the ratio of the emulsifier to the oil agent is higher than the above, the emulsifying effect will not improve much and the cost of the emulsifier will increase, which is not desirable.

(Oil agent)
As an oil agent, for example, it contains a large amount of oleic acid and stearic acid, so it has a low viscosity, smooth and moist feel, and has excellent permeability, and it also has high moisturizing properties because it contains long chain fatty acids and phytosterols. Shea butter that has the following properties is used.
Note that the oil agent is not limited to shea butter, but may be any oil that has an emollient effect, such as avocado oil, almond oil, olive oil, camellia oil, sesame oil, rice bran oil, safflower oil, soybean oil, corn oil, rapeseed oil, and kyonin oil. Oil, persic oil, peach kernel oil, castor oil, sunflower oil, grape seed oil, cottonseed oil, coconut oil, wheat germ oil, rice germ oil, evening primrose oil, hybrid sunflower oil, macadamia nut oil, meadowfoam oil, hazelnut oil, palm kernel. Oil, palm oil, coconut oil, cacao butter, wood wax, mink oil, turtle oil, egg yolk oil, beef tallow, milk fat, lard, horse oil, jojoba oil, carnauba wax, candela wax, rice bran wax, orange roughy oil, Beeswax, shellac, lanolin, montan wax, squalene, squalane, liquid paraffin, paraffin, microcrystalline wax, petrolatum, soft liquid isoparaffin, hydrogenated polyisobutylene, ozokerite, ceresin, α-olefin oligomer, polybutene, polyethylene, etc. as desired. Can be used.
The oil agent is blended in a proportion of 0.001% by mass to 0.100% by mass based on the total components of the medicinal solution. If it is less than 0.001% by mass, the effect of the oil agent will not be exhibited so much, which is not desirable. Moreover, if the amount is more than 0.100% by mass, the viscosity becomes high, stickiness occurs, and the feeling of use deteriorates, which is undesirable.

(emulsifier)
In addition, emulsifiers include nonionic substances such as polyoxyalkylene alkyl ethers, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene alkyl esters, polyoxyalkylene sorbitan alkyl esters, sorbitan alkyl esters, polyethylene glycol, polypropylene glycol, etc. A surfactant or the like is used.
Note that it is desirable that at least two or more types of emulsifiers be blended. Since oil agents such as shea butter are composed of multiple types of fatty acids, they can be made easier to emulsify by blending multiple types of emulsifiers.

(moisturizer)
Additionally, a moisturizer may be added to the chemical solution. Glycerin, which is less irritating to the skin, is used as a humectant, and by combining this with an oil agent, the moisture retention of Wet Sheet S can be increased, making it possible to wipe away dirt without having to rub it repeatedly. This makes it possible to reduce skin irritation.
The humectant is blended in a proportion of 1% by mass to 10% by mass based on the total components of the medicinal solution. If it is less than 1% by mass, the moisturizing effect will not improve much, and if it is more than 10% by mass, the viscosity of the chemical solution will become too high, resulting in poor impregnating performance. Moreover, it is undesirable because it becomes sticky and the usability deteriorates.

(Preservative)
In addition, hexylglycerin or ethylhexylglycerin may be added as a preservative to the medicinal solution, and it may be commercially available, chemically synthesized, natural derived from animals or plants, fermented or genetically recombinant. may be used. Furthermore, hexylglycerin or ethylhexylglycerin is a substance that has a broad antibacterial spectrum and has a high antibacterial effect. Moreover, hexylglycerin or ethylhexylglycerin has a moisturizing function, and by containing it, the moisture retention property of the wet sheet S can be improved.

Preservatives also include sodium benzoate. Sodium benzoate is a substance that has an antibacterial effect against, for example, mold, yeast, aerobic bacteria, and the like.
Sodium benzoate exhibits its antiseptic effect at pH 5 or lower. That is, when the pH of the chemical solution is higher than 5, the antiseptic effect of sodium benzoate is almost lost. Additionally, in general, when the pH is lower than 3, it becomes strongly acidic, which may irritate the skin and cause rough skin. For this reason, it is desirable that the pH of the chemical solution be adjusted to a range of 3 to 5.

Specifically, ethylhexylglycerin is blended in a proportion of 0.05% to 0.10% by mass, and sodium benzoate is blended in a proportion of 0.075% to 0.100% by mass, based on all the components of the drug solution.
Alternatively, hexylglycerin is blended in a proportion of 0.1% by mass to 0.5% by mass, and sodium benzoate is blended in a proportion of 0.05% by mass to 0.10% by mass, based on all the components of the drug solution.
By using such a combination, the antiseptic effect can be exhibited more effectively.

Other preservatives that may be added include, for example, phenoxyethanol, benzalkonium chloride, cetylpyridinium chloride, and chelating agents.

(Impregnation rate)
Further, the impregnation rate of this chemical solution can be 200% by mass to 500% by mass based on the dry weight of the base sheet 10.
Note that the conditions for measuring the dry weight of the base sheet 10 are a temperature of 25° C. and a humidity of 40%. Further, an impregnation rate of 200% by mass means that 200g of the chemical solution is impregnated with respect to the base sheet 10 with a dry weight of 100g, and an impregnation rate of 500% by mass means a base sheet 10 with a dry weight of 100g. This means that 500g of the chemical solution is impregnated per 10mm.
If the impregnation rate is less than 200% by mass, the liquid will not penetrate sufficiently and uneven impregnation will occur, making it easy for the components in the chemical to be unevenly distributed. If the impregnation rate is more than 500% by mass, the chemical will drip during use. It becomes easier.

[Wet sheet manufacturing method]
Next, a method for manufacturing the wet sheet S will be explained.
The wet sheet S includes, for example, a lamination process in which a plurality of fiber layers are laminated to produce the base sheet 10, a coating process in which a CNF solution is applied to the base sheet 10, and a heat drying process in which the base sheet 10 is thermally dried. step, and a drug solution impregnation step of impregnating an emulsion-based drug solution.

(Lamination process)
In the lamination process, the base sheet 10 in which a plurality of fiber layers are entangled with each other in their boundary regions can be produced by a hydroentangling method.

(Coating process)
The coating process is a process of coating CNF on the base sheet 10, and the method is to dissolve CNF in a solvent to form a CNF dispersion, apply this CNF dispersion on the base sheet 10, and dry it. A known method can be used, such as depositing the film on the target sheet. Note that when liquid CNF is applied to the base sheet 10 using the manufacturing method of applying liquid CNF in this way, although it partially penetrates into the sheet, the CNF concentrates on the surface, so that CNF can be attached and formed on the outer layer. . The solvent in which CNF is dispersed is not particularly limited, but water, lower alcohols such as ethanol, and volatile organic solvents such as acetone can be used.
The CNF dispersion liquid can be applied by any conventionally known application method, such as spraying onto the target surface or a transfer method using a letterpress method.

(Heat drying process)
In the heat drying step, the base sheet 10 coated with the CNF solution is left to dry in a constant temperature bath, or the base sheet 10 is dried by directly contacting the surface of a heating roll such as a Yankee drum. Any heat drying method using conventionally known heat drying equipment can be used.
Further, as the drying equipment, equipment that uses infrared irradiation may be used. In this case, a plurality of infrared ray irradiation units are arranged in parallel in the transport direction of the base sheet 10, and the base sheet 10 being transported is irradiated with infrared rays to dry it. Since moisture is heated and dried by infrared rays, uniform drying is possible and wrinkles can be prevented.
In the present invention, in order to prevent the CNF applied to the surface of the base sheet 10 from peeling off, it is preferable to perform thermal drying using a constant temperature bath or an infrared irradiation device.

(emboss process)
In the embossing step, the high fiber density region 11 can be formed, for example, by hot embossing at a temperature of 80° C. to 130° C. and an embossing pressure of 0.2 MPa to 1.0 MPa.
By this embossing process, when the wet sheet S has a multilayer structure, the fibers of the inner layer enter into the fibers of the outer layer and come out to the surface or near the surface of the outer layer.
As a result, if the inner layer contains hydrophilic fibers, they will come out on or near the surface of the outer layer, making it easier to wipe away liquid stains.
Note that the low fiber density region 12 can be formed by designing the embossing roll that forms the high fiber density region 11 so as to exclude the shape of the low fiber density region 12.

(Chemical impregnation process)
In the chemical liquid impregnation process, the heat-dried base sheet 10 is impregnated with an emulsion-based chemical liquid, but a two-fluid nozzle spray method using a spray coating device, a rotor dampening spray method, Alternatively, known roll transfer techniques such as a doctor chamber method using a transfer roll, a two-roll method using a pickup roll, or a three-roll method using a pickup roll can be employed.
The rotor dampening spray method has the advantage that a small amount of spray liquid can be uniformly applied while suppressing the scattering of mist droplets, and that the spray speed, the particle size of the mist, etc. can be easily adjusted. In addition, the doctor chamber method has the advantage that the amount of impregnated chemical solution can be adjusted in detail by designing the number of cells and the number of lines of the transfer roll.

Note that the manufacturing process of the wet sheet S of this embodiment includes a process of applying (impregnating) CNF to the base sheet 10 and drying it (coating process, heat drying process), and a process of applying CNF to the base sheet 10 and drying it (coating process, heat drying process). It is only necessary to include a step of applying (impregnating) the sheet 10 with an emulsion-based chemical solution (chemical solution impregnation step), and other steps may be added as appropriate.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

[Sample creation]
First, 50% of rayon with a fiber diameter of 1.67 dtex and fiber length of 38 mm was entangled with 50% of PET with a fiber diameter of 1.56 dtex and fiber length of 38 mm using the hydroentangling method.The size was 14 cm x 14 cm, and the basis weight was 35 g. A base sheet 10 of /m ² was prepared.
Next, 0.47g of a CNF solution containing 1% by mass of mechanically treated CNF and 99% by mass of purified water was applied (CNF application amount: 0.24g/m ² ), and the mixture was placed in a constant temperature bath at 60°C for 10 minutes. It was left to dry under heat to produce a CNF sheet.
Next, the stratum corneum moisture content was measured at 5 cm, 8 cm, 11 cm, 14 cm, and 17 cm from the wrist, and the following Comparative Examples 1-4 and Example 1 were performed using the base sheet 10 or the CNF sheet. Note that Moisture Checker MY707S (manufactured by Scala Co., Ltd.) was used to measure the stratum corneum moisture content.

(Example 1)
A CNF sheet was impregnated with 340% by mass of an emulsion-based chemical solution (hereinafter referred to as emulsion A) formulated in the proportions shown in Table I below, and was gently wiped 5 times at a distance of 17 cm from the wrist.

(Comparative example 1)
Nothing was done 5 cm from the wrist.
(Comparative example 2)
The base sheet 10 is impregnated with 340% by mass of 0.1 mol/L sodium hydrogen carbonate solution (alkaline solution) containing 0.84% by mass of sodium hydrogen carbonate and 99.16% by mass of purified water, and An 8 cm area was gently wiped 5 times.
(Comparative example 3)
The base sheet 10 was impregnated with 340% by mass of a water-based chemical solution blended in the proportions shown in Table I below, and a portion 11 cm from the wrist was lightly wiped five times.
(Comparative example 4)
The base sheet 10 was impregnated with 340% by mass of emulsion A, and a portion 14 cm from the wrist was lightly wiped five times.

[Test: Moisturizing performance investigation]
After the operations in Comparative Example 1-4 and Example 1, keratin moisture at each location after 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 45 minutes, and 60 minutes Regarding the amount, the rate of change (%) from before the operation of each Comparative Example and Example was measured.
Such a test was conducted three times on different days, and the average value of the rate of change in stratum corneum water content after the operation of each comparative example and example was calculated.
The results of the test are shown in Table II.

[evaluation]
Comparing Comparative Examples 1-4, it can be seen that the moisture content of the stratum corneum can be increased by wiping with the base sheet 10 impregnated with an emulsion-based chemical solution. However, when comparing Example 1 and Comparative Example 4, the base sheet It can be seen that the moisture content of the stratum corneum can be further increased by impregnating the CNF sheet coated with CNF in No. 10 with an emulsion-based chemical solution.
It is presumed that this is because two types of protective films are formed on the skin by the oil contained in the emulsion-based drug and the CNF applied to the base sheet 10, thereby increasing moisturizing properties.

(Effects of embodiment)
As shown above, by impregnating the base sheet 10 coated with CNF with an emulsion-based chemical solution, the wet sheet has better moisturizing properties than a wet sheet in which the base sheet 10 is impregnated with an emulsion-based chemical solution. S can be generated.
Furthermore, in general, when CNF is added to a chemical solution, the viscosity of the chemical solution increases, so it is difficult to uniformly impregnate the base sheet 10 with CNF. This problem does not arise because the CNF sheet coated with CNF is impregnated with a chemical solution.

In addition, it goes without saying that the specific detailed structure and the like can also be changed as appropriate.
For example, the wet sheet S is used for baby wipes, adult body wipes, etc., but the present invention is not limited thereto. Further, the chemical liquid with which the wet sheet S is impregnated can also be changed depending on its use.

S Wet sheet 10 Base sheet

Claims (5)

A wet sheet in which a base sheet is impregnated with a chemical solution,
The chemical solution contains shea butter as an oil agent, PEG-20 glyceryl triisostearate as an emulsifier, and PEG-8 (caprylic acid/capric acid) glyceride ,
A wet sheet characterized in that the base sheet is coated with cellulose nanofibers. The wet sheet according to claim 1, wherein the chemical solution contains 0.001% by mass to 0.100% by mass of the oil agent. The wet sheet according to claim 1 or 2, wherein the chemical solution is impregnated in an amount of 200% to 500% by mass based on the dry weight of the base sheet. The wet sheet according to any one of claims 1 to 3, wherein the cellulose nanofibers are applied to the base sheet at 0.1 g/m ² to 10.0 g/m ² . . A method for manufacturing a wet sheet, the method comprising:
a coating process of applying a cellulose nanofiber solution to a base sheet;
a heat drying step of heat drying the base sheet;
A chemical liquid impregnation step of impregnating the base sheet with a chemical liquid containing shea butter as an oil agent, PEG-20 glyceryl triisostearate as an emulsifier, and PEG-8 (caprylic acid/capric acid) glycerides. A method for manufacturing a wet sheet.

Images