TWI384959B - Wipes with wipes and wipes - Google Patents

Description

Sheet and wet wipes for wet wipes

The present invention relates to a sheet substrate for use in a wet towel impregnated with a liquid. Further, the present invention relates to a wet tissue impregnated with a liquid in a sheet substrate.

When a plurality of wet tissues formed by impregnating a liquid in a sheet substrate are stacked and stored in a container, the liquid tends to move downward under the influence of gravity, resulting in a different content of liquid in each sheet. Therefore, when a wet wipe is used, the performance of the liquid may not be sufficiently exhibited. Moreover, the use of the liquid is less likely to cause a decrease in the feeling of use. Further, depending on the situation, liquid can accumulate at the bottom of the container, causing waste of the liquid. For example, when the wet wipe is a makeup remover wiper, the cleanness of the upper sheet is deteriorated in the overlapped sheet, and the lower sheet is sticky and the touch is deteriorated.

In order to prevent the liquid from moving even if the plurality of wet wipes are overlapped and stored, a melt-blown nonwoven fabric using a polyolefin resin having a basis weight of 15 to 200 g/m ² is proposed (refer to Japanese Patent Laid-Open No. SHO 63-54137). Bulletin). The meltblown nonwoven fabric is characterized in that at least 65% of the pores have a size of 20 to 60 μm.

In addition to this technique, the present applicant has previously proposed a sheet substrate for wet wipes as described below (refer to Japanese Laid-Open Patent Publication No. 2005-330608), which is composed of one or more of 55% by weight or more. The fiber sheet of the hydrophilic fiber is composed of a fiber diameter of 0.2 to 5.5 dtex, and a fiber-to-fiber distance of the fiber constituting the sheet is 10 to 35 μm.

However, in the technique disclosed in Japanese Laid-Open Patent Publication No. SHO63-54137, since the polyolefin resin is hydrophobic, when the melt-blown nonwoven fabric as a raw material is impregnated into the aqueous liquid, it is necessary to The non-woven fabric is hydrophilized, so that it is labor-intensive and time-consuming to manufacture. Further, although depending on the manufacturing conditions, there are cases where the melt-blown non-woven fabric is often inferior in hand feeling, especially when it is used to wipe the skin.

In the technique disclosed in Japanese Laid-Open Patent Publication No. 2005-330608, there is an advantage that the touch of the sheet is good, and even when the sheet is impregnated with liquid and a plurality of sheets are stored in a laminated state, the liquid There are also fewer moves. However, it is highly desirable to have a sheet substrate which is more tactile and less likely to cause liquid movement.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a sheet material for a wet tissue which is further improved in performance than the prior sheet substrate.

The present invention achieves the above object by providing a sheet substrate for a wet tissue which is impregnated with a liquid to form a wet tissue, and the sheet substrate comprises two or more types. The fiber sheet of the hydrophilic fiber, the total amount of the two or more kinds of hydrophilic fibers is 60% by weight or more, and the ratio of the aspect ratio of the two or more types of the hydrophilic fibers including 60 to 90% by weight of the cross section is 1: 1 to 1:4, a hydrophilic fiber having a hollow cross-sectional shape, and 10 to 40% by weight of a hydrophilic fiber having a circular cross-sectional shape, and at least one of the two or more kinds of the hydrophilic fibers has a fiber diameter of 0.2 to 5.5 dtex, and the average interfiber distance of the fibers constituting the above fiber sheet is 10 to 35 μm.

Hereinafter, the present invention will be described based on preferred embodiments of the present invention. The sheet substrate of the present invention is one which is impregnated with a liquid to form a wet tissue, and the sheet substrate of the present invention is in a dry state before being impregnated with the liquid. The sheet substrate is composed of a fiber sheet comprising a fibrous material. As the fiber sheet, various woven fabrics, non-woven fabrics, knitted fabrics, and the like, and the like can be used. In terms of liquid retention performance and manufacturing cost, it is preferred to use various nonwoven fabrics.

When a non-woven fabric is used as the fiber sheet, for example, various types of non-woven fabrics such as a dry water spun fabric, a wet water needle non-woven fabric, a gas-jet-spun nonwoven fabric, a hot-air-spun nonwoven fabric, a melt-blown nonwoven fabric, and a spunbonded nonwoven fabric can be used. Among these nonwoven fabrics, it is preferred to use a dry water needle nonwoven fabric or a wet water needle nonwoven fabric in terms of liquid impregnation performance, holding property, and hand feeling.

In particular, when a dry water needle non-woven fabric or a wet water needle non-woven fabric is used as the fiber sheet, it is preferable to use a method of suppressing liquid movement during storage of the wet tissue. The water pressure at which the fiber web is interlaced by the water flow is higher than the usual production conditions, and a water needle non-woven fabric in a hydrated state is obtained, and the water needle non-woven fabric is pressed by a press roll and then dried.

In the case where a dry water needle nonwoven fabric or a wet water needle nonwoven fabric is used as the fiber sheet, it is preferred that the water pressure when the fibers are interlaced by the water flow is higher than the usual production conditions. The reason for this is that a non-woven fabric having a small average fiber-to-fiber distance can be obtained, thereby suppressing the movement of the liquid. The water pressure at which the water flows are interlaced can be appropriately adjusted according to the basis weight of the fibers. For example, when the basis weight of the fiber is 20 to 150 g/m ² , the water pressure is preferably 3 to 35 MPa, particularly preferably 10 to 30 MPa, particularly preferably 15 to 25 MPa. The water flow interlacing can also be carried out several times depending on the purpose. Water pressure can be applied from the surface or back of the fiber or it can be applied from both sides. Further, the water pressure can be adjusted to a plurality of stages, and at this time, the maximum water pressure can be adjusted to the above water pressure.

Further, when a dry water needle non-woven fabric or a wet water needle non-woven fabric is used as the fiber sheet, it is preferred to press the pressing roller for pressing the water needle non-woven fabric in a water-containing state after being interlaced by the water flow. Higher than the usual conditions. The pressing conditions of the press rolls are preferably from 1 to 60 kg/cm, more preferably from 5 to 55 kg/cm, and even more preferably from 10 to 50 kg/cm. Further, the pressing of the pressure roller may be carried out after the water needle non-woven fabric in a hydrated state is dried, and the linear pressure is 30 to 55 kg/cm. However, in terms of suppressing the movement of the liquid, the degree of the hand feeling, the simplicity of the manufacturing steps, the cost, and the like, it is preferred to press the water-needle non-woven fabric in a hydrated state by a press roll.

The reason why the liquid pressure can be suppressed by pressing the water pressure higher than the usual production conditions or using a press roll is not sufficiently clarified, and the inventors have estimated that the average interfiber distance becomes small, and the liquid due to gravity Whether the resistance of the movement becomes larger will be one of the reasons.

As apparent from the above description, in the present invention, it is important that the sheet substrate is one in which the average interfiber distance of the fibers constituting the sheet is small. Specifically, it is important to use an average interfiber distance of 10 to 35 μm. When the average interfiber distance is within this range, the movement of the liquid is less likely to occur during the storage of the wet tissue layer, and a good hand feeling can be ensured. From the viewpoint of further suppressing the movement of the liquid, the average interfiber distance is preferably from 12 to 34 μm, more preferably from 14 to 33 μm. The average interfiber distance can be calculated from the following formula.

Wherein w represents a basis weight (g/m ² ), L represents a thickness (cm), α represents a composition (wt%) of the i-th fiber, Dt _i represents a fiber diameter (dtex) of the i-th fiber, and Δ represents The average center-to-center distance (μm), and Fd represents the average fiber diameter (μm).

In order to increase the diffusibility of the liquid, the sheet substrate of the present invention preferably has an orientation of 2.5 to 4.0. The orientation described herein refers to molecular orientation, which can be determined, for example, using MOA-2001A from Prince Measurement Machines, Inc.

The sheet substrate of the present invention preferably has a reflectance of 45 to 99% upon drying. By making the reflectance at the time of drying 45% or more, it is possible to easily distinguish the stain at the time of use, and by making the reflectance at the time of drying 99% or less, the sheet can be hardened and the touch is good. The reflectance was calculated by measuring the average of five parts at a wavelength of 480 nm using an SE-2000 spectrophotometer manufactured by Nippon Denshoku Industries Co., Ltd., and calculating the average value.

The sheet substrate of the present invention preferably has a SMD value of a KES friction coefficient of 2.10 μm or more in the CD direction and 1.42 μm or less in the MD direction. By making the SMD value in the CD direction 2.10 μm or more, the stain erasability can be improved, and by setting the SMD value in the MD direction to 1.42 μm or less, the touch feeling at the time of use can be excellent. In order to make the SMD value the above value, for example, in the case of the water needle method, the water pressure or the pressure of the pressure roller can be adjusted.

The SMD value of the KES friction coefficient can be obtained by setting a sheet substrate in a KES-SE measuring machine manufactured by Kato Tech to make a piano wire having a diameter of 0.5 mm at a contact force of 50 gf. The surface characteristics were measured by moving on the surface of the sheet substrate at a speed of 1 mm/sec. Each sample was measured three times and the average value was determined. The detailed description of the KES method is described in detail in the "Standard Analysis Method for Hand Evaluation (2nd Edition)" issued by the Japan Society of Mechanical Engineers.

The sheet substrate of the present invention is preferably impregnated with 400% of a liquid represented by a detergent or the like, and the sustained release rate of the liquid in a state of applying a load of 5 g/cm ² for 10 seconds is 280% or more. . By allowing the sustained release rate to be 280% or more, a sufficient amount of liquid can be continuously released from the sheet, and the stain removal performance can be improved. A liquid such as a detergent that is continuously released from the sheet, such as a stain that dissolves the skin or a cosmetic stain, is absorbed from the skin and absorbed into the sheet substrate, whereby the stain of the skin can be removed.

The reason why the measurement condition of the sustained release rate is "the state in which the load of 5 g/cm ^{2 is} applied for 10 seconds" is that the load and time are substantially the same as those when the person wipes the skin. The sustained release rate was measured by the following method. The weight A of the sheet substrate adjusted to a size of 50 mm × 200 mm was measured to impregnate a wiping substrate having a weight equivalent to 4 times the weight A. Let the weight after impregnation be B. Then, kimtowel (manufactured by Crecia Co., Ltd.) was used to wrap the entire sheet substrate impregnated with the wiping substrate. Then, on a sheet substrate wrapped by kimtowel, an acrylic plate of 100 mm × 100 mm was placed, and a weight was placed thereon to apply a load of 500 g in total. After removing the weight and the acrylic plate after 10 seconds, the weight C of the sheet substrate was measured, and the sustained release rate was calculated by the following formula.

Sustained release rate (%) = (B-C) / A × 100

The sheet substrate may be composed of a single layer of fiber sheets, or may be a multilayer structure in which a plurality of layers of the same or different types of fiber sheets are laminated.

The fiber sheet constituting the sheet substrate contains two or more kinds of hydrophilic fibers in a total amount of 60% by weight or more, preferably 70% by weight or more, and more preferably 80% by weight or more. Of course, the fiber sheet may also be composed of 100% or more of hydrophilic fibers. Among the two or more kinds of hydrophilic fibers, as one of the hydrophilic fibers, a hydrophilic fiber having a cross-sectional length ratio of 60 to 90% by weight of 1:1 to 1:4 and a hollow cross-sectional shape is included. It is preferably 65 to 85% by weight. When the aspect ratio of the profile exceeds 1:4, the tactile sensation deteriorates and the average interfiber distance becomes difficult to control. The hydrophilic fiber having a hollow cross-sectional shape is preferable because it can hold a liquid in the hollow portion and has elasticity. When the proportion of the hollow hydrophilic fibers is less than 60% by weight, the liquid retainability of the sheet substrate is lowered, and the elasticity of the fibers is lowered. If it exceeds 90% by weight, the touch of the sheet substrate may be deteriorated.

Among the two or more kinds of hydrophilic fibers, the other one of the hydrophilic fibers contains 10 to 40% by weight of a hydrophilic fiber having a circular cross-sectional shape, preferably 15 to 35% by weight. Further, the cross-sectional shape described herein is a circular hydrophilic fiber, and does not include the hollow fiber previously described. That is, the hydrophilic fiber-based solid fiber having a circular cross-sectional shape. Since the friction of the fiber having a circular cross section is small, the touch of the sheet substrate including the same becomes smooth. If the proportion of the hydrophilic fibers having a circular cross-sectional shape is less than 10% by weight, the sheet substrate cannot be imparted with sufficient smoothness. If it exceeds 40% by weight, the fibers will be fluffed by friction.

As the hydrophilic fiber, a fiber which is originally hydrophilic and a fiber which is not hydrophilic and which is hydrophilic by hydrophilic treatment can be used. Examples of the originally hydrophilic fiber include natural fibers of cellulose fibers, regenerated cellulose fibers, purified cellulose fibers, semi-synthetic fibers, and acrylic fibers. Specific examples of the cellulose-based fibers include natural fibers such as cotton, hemp, wool, and pulp, regenerated cellulose fibers such as bismuth and cuprammonium fibers, and purified cellulose fibers such as Lyocell (registered trademark) and Tencel (registered trademark). Semi-synthetic fibers such as acetate. The fiber which is not hydrophilic and is hydrophilic by the hydrophilization treatment is, for example, a fiber formed by hydrophilizing a fiber containing a hydrophobic resin such as a polyolefin resin or a polyester resin. Among these fibers, cotton, enamel, copper ammonium fiber, Lyocell, and Tencel are preferably used in terms of good hand feeling. The hydrophilic fiber having a cross-sectional longitudinal length ratio of 1:1 to 1:4 and a hollow cross-sectional shape is preferably cotton. On the other hand, as the hydrophilic fiber having a circular cross-sectional shape, Lyocell and Tencel are preferred. In the case of using Lyocell or Tencel, in the manufacturing steps of the sheet substrate including the water flow interlacing step and the pressing step as described above, it is also possible to further increase the water pressure or further increase the pressing pressure as needed, thereby making the fiber fibers Chemical. Thereby, the liquid retainability of the sheet substrate can be further improved.

In addition to a hydrophilic fiber having a cross-sectional aspect ratio of 1:1 to 1:4 and a hollow cross-sectional shape, such as cotton, it may contain a specific amount of hydrophilic fibers having a circular cross-sectional shape, such as Lyocell or Tencel. Thereby, the sheet substrate of the present invention is preferred because it has a better touch.

The hydrophilic fibers having a circular cross-sectional shape, such as Lyocell and Tencel, may be used alone or in combination of two or more. Since Lyocell and Tencel are purified cellulose fibers made of a solvent, for example, compared with ruthenium, there is an advantage that odor is less likely to occur when stored under impregnation heating.

Refined cellulosic fibers such as Lyocell and Tencel may also have curl. The number of crimps in this case is preferably from 0.1 to 3/cm. The sustained release property is excellent by the fact that the sheet substrate containing the fiber has a curl to impregnate the cleaning liquid therein. Moreover, since the sheet substrate exhibits moderate elasticity, it is excellent in touch when used. Further, since the Lyocell can be naturally curled, the number of crimps is not particularly limited.

The hydrophilic fiber used in the present invention has a fiber diameter of 0.2 to 5.5 dtex, preferably 0.5 to 4.4 dtex, and more preferably 0.8 to 3.3 dtex. When a hydrophilic fiber having a cross-sectional length ratio of 1:1 to 1:4 and a hollow cross-sectional shape is used, for example, when a cotton of natural fiber is used, since the cross-sectional shape is not a true circle, When a true circle corresponding to the cross-sectional area surrounded by the periphery of the cross-section is considered and the diameter is calculated from the true circle, it may be included in the range of the fiber diameter. In this case, when the fiber diameter of the fiber which is not a true circle is expressed, a expression such as "dtex equivalent" is used. When fibers having a fiber diameter of this range are used, the average interfiber distance previously described can be easily controlled to an appropriate distance. In the present invention, two or more kinds of hydrophilic fibers are used, and the fiber diameter of at least one hydrophilic fiber is required to be within the above range. It is preferred that the fiber diameter of all the hydrophilic fibers is within the above range.

When cotton is used as the hydrophilic fiber, the Micronair fineness (μg/in) is preferably 2.5 to 6.0 μg/in, and when it is 3.1 to 4.4 μg/in, the touch is also good, so it is better.

The fiber length of the hydrophilic fiber is not particularly limited, and it is preferably from 5 to 70 mm in terms of touch and productivity in use.

In the sheet substrate, in order to suppress the movement of the liquid, improve the erasability, and impart heat sealability, it is also possible to add ultrafine fibers (for example, a thickness of 0.2 to 1.2 dtex before division) or a binder fiber. As the ultrafine fibers, ultrafine fibers or divided fibers comprising polyethylene, polypropylene, polyester, polyamide, polystyrene, nylon, and acetate are preferred. In the case of using the split fiber, as long as the fiber diameter after the division is within the above range, the fiber diameter and the number of division before the division are not limited. The binder fiber is not particularly limited, and is preferably a core-sheath type composite fiber such as PET/PE, PP/PE, PP/PP, or PET/PET which can be heat-sealed at a low temperature. Further, in order to improve various characteristics of the sheet substrate, fibers other than the above hydrophilic fibers may be added. For example, to increase the strength, it is also possible to add heat-melting fibers. The amount of the fibers other than the hydrophilic fibers in the sheet substrate is preferably from 5 to 50% by weight, particularly preferably from 10 to 40% by weight.

Although the sheet substrate is also dependent on its basis weight, its thickness is preferably 0.22 to 0.85 mm, particularly preferably 0.24 to 0.45 mm, and particularly preferably 0.26 to 0.37 mm. Further, the basis weight of the sheet substrate is preferably from 20 to 150 g/m ² , particularly preferably from 50 to 100 g/m ² . If the thickness and the basis weight are within this range, the liquid retaining performance can be sufficiently improved. The basis weight was determined by cutting the sheet substrate into a size of 100 mm × 100 mm and measuring the weight, and converting the weight into a weight of 1 m ² . The thickness was cut into a size of 100 mm × 100 mm and measured under a load of 20 gf/cm ² .

The sheet density of the sheet substrate is preferably 0.05 to 0.40 g/cm ³ , more preferably 0.10 to 0.36 g/cm ³ , more preferably 0.15 to 0.32 g/cm ³ . By setting the sheet density to 0.05 g/cm ³ or more, the liquid retaining ability in the sheet can be improved, and the movement of the liquid during the storage of the wet tissue can be suppressed. By setting the sheet density to 0.40 g/cm ³ or less, the hand feeling can be improved and the feeling of use can be improved.

The sheet density was measured by the following method. The sheet substrate was cut into a size of 100 mm × 100 mm, and the weight was measured, and the weight was converted into a weight of 1 m ² to determine the basis weight. Further, the thickness of the cut sheet substrate was measured under a load of 20 gf/cm ² . The basis weight was obtained by dividing the obtained basis weight by the thickness.

The amount of the saturated liquid of the sheet substrate is preferably from 50 to 1000% per unit weight, particularly preferably from 100 to 600%. Thereby, a sufficient amount of liquid can be maintained. The amount of saturated liquid depends on the gap formed by the fibers constituting the sheet substrate and the material of the fiber itself. Therefore, the liquid retention performance can be improved not only by thinning the thickness of the sheet substrate, but also to increase the performance. The amount of saturated liquid was determined by cutting the sheet substrate into a size of 100 mm × 100 mm and measuring the weight thereof, and immersing the sheet substrate in ion-exchanged water for 15 minutes or more, and taking out the liquid droplet after taking out The amount of the saturated liquid was determined by dropping the weight for 1 minute or more, measuring the weight, and calculating the difference between the weights before and after the immersion.

The porosity of the sheet substrate is preferably 70 to 99%, particularly preferably 85 to 99%. By setting the above porosity to 70% or more, the impregnated liquid can be sufficiently maintained. Further, by setting the void ratio to 99% or less, productivity can be improved. The void ratio is calculated by the following formula.

Void ratio (%) = (ρ - ρ') / ρ × 100 (where ρ: specific gravity of the sheet, ρ': apparent specific gravity of the sheet)

The sheet substrate of the present invention is impregnated with various liquids to form a wet wipe. The type of the liquid to be impregnated can be appropriately selected depending on the specific use of the wet wipe. For example, when a wet wipe is used as a makeup remover wipe, as the liquid, an aqueous liquid containing a surfactant, an oil-in-water emulsion composition (O/W emulsion emulsion), or an oil-in-water emulsion composition can be used ( W/O emulsion emulsion), oil gel, cream, oil. Particularly preferred is an aqueous solution containing a nonionic surfactant and glycerin. More preferably, the nonionic surfactant is polyethylene glycol monolaurate. In the case of cleaning aqueous and oily cosmetics having high skin adhesion such as mascara, it is preferred to contain 0.01 to 0.5% by mass of a water thickener, and 5 to 30% by weight of a boiling point of 160 to 300 ° C. The oil agent and the O/W emulsion of water are more preferably an O/W emulsion emulsion of the above-mentioned oil agent which is an isoparaffin having a boiling point of 160 to 300 °C. As the isoalkane, a product Marukazol R (Maruzen Petrochemical Co., Ltd.) or an IP solvent 1620, 2028 (Iwasu Petrochemical Co., Ltd.) or the like can be used.

The impregnation amount of the liquid in the sheet substrate also depends on the specific use of the wet tissue, but it is preferred that the impregnation amount per unit weight of the sheet substrate is 100 to 600%, particularly preferably 200 to 450%.

The wet wipe obtained in such a manner can suppress the movement of the liquid even if a plurality of the wet wipes are stacked and stored. Due to the impregnation of the liquid, the density of the flakes is different from the density of the flakes prior to impregnation of the liquid, but there is not much difference between the two flake densities. Therefore, the movement of the liquid in the wet wipe can be suppressed. Specifically, the sheet density of the wet wipe is preferably from 0.05 to 0.40 g/cm ³ , particularly preferably from 0.15 to 0.32 g/cm ³ . Moreover, the average interfiber distance of the wet wipes is also not much different from the average interfiber distance of the sheet substrate before impregnation of the liquid. Specifically, the average interfiber distance of the wet wipes is preferably from 10 to 35 μm, particularly preferably from 14 to 33 μm.

The wet wipes having the sheet substrate of the present invention can be preferably used for various wiping purposes for humans or animals, and for objects. For example, it can be suitably used as a makeup remover wipe, an antiperspirant wipe, a baby wipe, a pet wipe, a floor wipe, and the like.

[Examples]

Hereinafter, the present invention will be described in more detail by way of examples. However, the scope of the invention is not limited to the embodiment. "%" means "% by weight" unless otherwise specified.

[Example 1]

Using 70% of cotton with a fiber diameter of 1.7 dtex (the shape of the hollow is a hollow shape, the aspect ratio is 1:3), 30% of the Lyocell with a fiber diameter of 1.7 dtex (the cross-sectional shape is a circular shape) is used as a raw material, and the comb is used. The cotton machine produced a web having a basis weight of 60 g/m ² . The obtained fiber web is interlaced by a high-pressure water stream to obtain a water needle non-woven fabric in a hydrated state. The pressure of the water flow is 20 MPa. The fibrous web in a hydrated state is passed between a pair of press rolls for pressing. The conditions for pressing are 30 kg/cm. After pressing, a drying step is carried out to obtain a sheet substrate composed of a water needle non-woven fabric. The basis weight, thickness, sheet density, and average interfiber distance of the sheet substrate are shown in Table 3. In the sheet substrate obtained in such a manner, the cleaning liquid of the formulation 1 shown in Table 1 below was impregnated as a cleaning liquid to obtain a wet tissue. The impregnation rate of the cleaning liquid is 380%.

※1 acrylic. Manufacture of alkyl methacrylate copolymer BF Goodrich Co., Ltd. ※ 2 hydroxyethyl cellulose hydroxypropyl stearyl ether hydroxypropyl sulfonate (Japanese Patent Laid-Open No. 9-235301) *3 Light liquid isoparaffin (Boiling point is 175~185°C) Maruzen Petrochemical Co., Ltd.

[Embodiment 2]

The pressing line pressure is 35 kg/cm, so that the composition of the sheet substrate is 70%, the fiber diameter is 1.7 dtex equivalent (the cross-sectional shape is hollow, the aspect ratio is 1:3), and the fiber is 30%. A wet wipe was obtained in the same manner as in Example 1 except that Tencel having a diameter of 1.7 dtex (the cross-sectional shape was a circular shape). The basis weight, thickness, sheet density, and average interfiber distance of the sheet substrate are shown in Table 3.

[Example 3]

A wet wipe was obtained in the same manner as in Example 1 except that the cleaning liquid of Formulation 2 shown in Table 2 below was impregnated.

[Comparative Example 1]

Using a 60% PET/PE core-sheath composite fiber with a fiber diameter of 9.0 dtex and a 40% PP/PP core-sheath composite fiber with a fiber diameter of 3.3 dtex as a raw material, a basis weight of 40 g/m was produced. ² sheet of hot air-woven non-woven fabric. In the sheet substrate, the cleaning liquid shown in the above Formula 1 was impregnated to obtain a wet wipe. The impregnation rate of the cleaning liquid is 380%. The basis weight, thickness, sheet density, and average interfiber distance of the sheet substrate are shown in Table 3.

[Comparative Example 2]

A PET/PE core-sheath fiber having a fiber diameter of 4.4 dtex was used as a raw material, and a fiber web having a basis weight of 50 g/m ^{2 was} produced by a carding machine. The obtained web was passed between hot embossing rolls to partially melt it, and a sheet substrate composed of a heat embossed nonwoven fabric was produced. In the sheet substrate, the cleaning liquid shown in the above Formula 2 was impregnated to obtain a wet wipe. The impregnation rate of the cleaning liquid is 380%. The basis weight, thickness, sheet density, and average interfiber distance of the sheet substrate are shown in Table 3.

[Comparative Example 3]

A fiber web having a basis weight of 45 g/m ^{2 was} produced by a card using a ruthenium fiber having a fiber diameter of 2.2 dtex as a raw material. The obtained fiber web is interlaced by a high-pressure water stream to obtain a water needle non-woven fabric in a hydrated state. The pressure of the water flow is 5 MPa. The fibrous web in a hydrated state is passed between a pair of press rolls for pressing. The condition for pressing is a line pressure of 4 kg/cm. After pressing, a drying step is carried out to obtain a sheet substrate composed of a water needle non-woven fabric. The cleaning liquid shown in the above formula 1 was impregnated into the sheet substrate obtained in such a manner as a cleaning liquid to obtain a wet tissue. The impregnation rate of the cleaning liquid is 380%. The basis weight, thickness, sheet density, and average interfiber distance of the sheet substrate are shown in Table 3.

[Performance Evaluation]

For the obtained sheet substrate, the difference in the impregnation rate before and after storage, the touch, and the cleaning power were evaluated by the following methods. Further comprehensive assessment is also carried out. The results of these are shown in Table 3 below.

[Difference in impregnation rate before and after storage]

The sheet substrate was cut into a size of 75 mm in length × 200 mm in length and impregnated with the cleaning liquid of Formulation 1. The impregnation rate was set to 380%. 50 sheets of the wipes obtained in this manner were placed in a pillow bag and sealed, and stored at 50 ° C for one month. After saving, place them until they return to room temperature. The wet wipes were taken out from the pillow pouch, and the impregnation rates of the second sheet from the top and the 49 sheets from the top were measured. Calculate the difference between the two, and use this value as the difference between the upper and lower impregnation rates. Further, the difference between the impregnation rates of the second sheet and the 49th sheet before and after storage was also determined. Further, since the sheet at the bottom and the sheet at the top may be affected by the pillow bag, they are not used as the measurement target. The impregnation rate is determined by measuring the weight of each wet towel, cleaning the sheet with a cleaning agent, and washing with distilled water, and measuring the weight of the dried sheet, and calculating it according to the following formula.

Impregnation rate (%) = (wet towel weight - dry sheet weight) × 100 / dry sheet weight

Evaluation. Regarding the second sheet and the 49th sheet ◎: the difference between the impregnation rate after storage and the impregnation rate immediately after preparation is within ±25% ○: the difference between the impregnation rate after storage and the impregnation rate immediately after preparation is ± Within 40% Δ: The difference between the impregnation rate after storage and the impregnation rate immediately after preparation is within ±60%×: The difference between the impregnation rate after storage and the impregnation rate immediately after preparation is greater than ±60%

. Difference between impregnation rates after storage of the second and 49th sheets ◎: Within ±25% O: Within ±40% △: Within ±60% ×: Greater than ±60%

[feeling]

Ten monitors were used to wipe the face with a wet wipe, and the touch of the skin was evaluated for sensitivity.

Evaluation ◎: 8 out of 10 people think that the touch is better.

O: 6 out of 10 people - 7 people think that the touch is better.

△: 4 out of 10 people - 5 people think that the touch is better.

×: Among 10 people, those who think that the touch is better are 3 or less.

[cleaning power]

In the evaluation of cleansing power, the most stubborn stains in the usual cosmetic stains are oily mascara and lipstick stains.

[Evaluation of the cleanliness of oily mascara]

0.0045 g of oily mascara (trade name Kose, Sport beauty fasio power stay mascara (Curl long) BK001, manufactured by Kose Co., Ltd.) was uniformly coated on a glass slide to a circular shape of 1.2 cm in diameter, and placed 12 Allow it to dry for an hour to obtain a sample stain. Each of the wet tissues was pressed against the sample stain for 5 seconds, and then wiped under a fixed pressure (100 g/cm ² ) to measure the number of wiping operations necessary to completely remove the sample stain.

Evaluation ◎: 5 times or less ○: 6 times or more, 10 times or less △: 11 times or more, 15 times or less ×: 16 times or more

[Evaluation of lipstick cleanliness]

A 0.02 g of a fixed amount of lipstick (trade name: Aube Lipstick RS151, manufactured by Kao Co., Ltd.) was applied to a circular shape on the inside of the front arm of the person to measure the color difference. After 30 minutes, each wet towel having an impregnation rate of 380% was applied to the lipstick stain, and after 5 times of wiping, it was cleaned. After cleaning, the color difference was measured, and the cleaning rate was calculated by the following formula based on the color difference before and after the cleaning.

Cleaning rate (%) = (1 - color difference after cleaning / color difference before cleaning) × 100

The color difference meter uses a Minolta color difference meter CR-300 (Minengda camera).

Evaluation ◎: 80% or more ○: 75% or more, less than 80% △: 50% or more, less than 70% ×: less than 50%

[Comprehensive Evaluation]

According to the following criteria, the difference in impregnation rate before and after storage of the second sheet, the difference in impregnation rate before and after storage of the 49th sheet, the impregnation rate difference between the second sheet and the 49th sheet, the touch and the cleaning power are 5 The project is evaluated.

◎: ◎ is three or more ○: ◎ is two Δ: ◎ is one ×: ◎ is 0

As is clear from the results shown in Table 3, the difference in the impregnation rate between the second sheet and the 49th sheet was compared with the wet sheet using the sheet substrate of each comparative example using the wet sheet of the sheet substrate of each of the examples. Smaller, the movement of the liquid is suppressed. Further, it is also clear that the wet tissue using the sheet substrate of each of the examples has a very good touch and is excellent in cleaning power.

[Industrial availability]

According to the sheet substrate of the present invention, the touch is good, and even if the liquid is impregnated and a plurality of sheet substrates are stored in a laminated state, the movement of the liquid is less. Therefore, the performance of the impregnated liquid can be fully exerted. Further, since the liquid system is released from the sheet in an appropriate amount, the cleanability is good.

Claims (6)

A sheet substrate for a wet tissue which is impregnated with a liquid to form a wet tissue, wherein the sheet substrate is a fiber sheet comprising two or more kinds of hydrophilic fibers, and the total amount of the two or more kinds of hydrophilic fibers is 60.重量% or more, two or more of the above hydrophilic fibers, comprising 60 to 90% by weight of a cross-sectional length ratio of 1:1 to 1:4 and having a hollow cross-sectional shape, and 10 to 40% by weight The cross-sectional shape is a circular hydrophilic fiber, and at least one of the two or more kinds of the hydrophilic fibers has a fiber diameter of 0.2 to 5.5 dtex, and an average interfiber distance of the fibers constituting the fiber sheet is 10 to 35 μm. The hydrophilic fiber-based natural fiber having a hollow cross-sectional shape and a hydrophilic fiber-based purified cellulose fiber having a circular cross-sectional shape. A sheet substrate as claimed in claim 1, which comprises a spunlace nonwoven fabric. The sheet substrate of claim 2, which is obtained by interlacing a web comprising two or more kinds of the above hydrophilic fibers by a water flow to obtain a water needle non-woven fabric in a hydrated state, and then performing the water needle non-woven fabric by pressing with a pressure roller. Dry and get. The sheet substrate of claim 1 or 2, wherein the fiber sheet comprises a single layer of nonwoven fabric. The sheet substrate of claim 1 or 2 has a thickness of 0.22 to 0.85 mm and a basis weight of 20 to 150 g/m ² . A wet tissue which is impregnated with a water-based thickener containing 0.01 to 0.5% by mass, 5 to 30% by mass of an oil having a boiling point of 160 to 300 ° C, and water in water, as in the sheet substrate of claim 1 A type of emulsified composition.