JP2022061414A5 - - Google Patents

Description

TECHNICAL FIELD The present invention relates to a tissue paper manufacturing method and a tissue paper product manufacturing method.

Tissue paper is mainly 2-ply, but in recent years, there is an increasing demand for multi-ply and thick tissue paper such as 3-ply and 4-ply.
Such multi-ply tissue paper is often regarded as a high-end product with a high product price. "Surface smoothness" and "softness" are required.

In the case of a multi-ply structure, if the basis weight of each ply is increased, the total thickness of each ply makes it possible to easily increase the paper thickness, and the "fluffy and bulky feeling" can be expressed.
However, when increasing the weight per unit area of each ply in this way, it is important to ensure the softness and smoothness of the ply as well as to create a "fluffy and bulky feeling".

Various types of tissue paper are commercially available, and one of the fields is moisturizing tissue containing a water-based moisturizing agent and lotion tissue.
Conventional moisturizing tissues and lotion tissues are manufactured to be soft and smooth quality so that the skin does not become red or painful even after repeated use, for people who frequently use tissue paper for hay fever or colds. It is

There are quite a few differences in the way tissue paper is used from country to country. This is believed to be based on differences in lifestyles or cultural styles.
Moisturizing tissues and lotion tissues in Japan are predominantly two-ply tissues, while in China, for example, three-ply tissues are predominant.

JP 2018-171254 A

In the conventional moisturizing tissue or lotion tissue in which three plies are laminated, or in the production thereof, a moisturizing agent is applied only to both outer layer sheets, and a moisturizing agent is not applied to the intermediate layer sheet.

In this conventional moisturizing or lotion tissue, a certain amount of moisturizing agent needs to be applied in order to make it feel soft to the user when in use.
On the other hand, however, a large amount of the moisturizing agent applied causes the outer surface of the outer layer sheet to become sticky, which is not preferable.

Accordingly, it is an object of the present invention to provide a method for producing a 3-ply or 4 -ply tissue paper and a method for producing a tissue paper product, in which the necessary softness is secured and the stickiness of the outer surface is reduced.

The tissue paper manufacturing method according to the present invention, which solves the above problems,
In manufacturing a tissue paper consisting of a laminated sheet in which 3 plies or 4 plies are laminated,
Each ply contains a water-based humectant that exhibits hygroscopicity,
Each ply has a difference in arithmetic mean height Sa according to ISO 25718 between its two sides,
applying the moisturizer to each of the plies;
Applying the moisturizing agent to the outer surface of each ply located outside the laminated sheet while the outer surface of each ply has the smaller arithmetic mean height Sa;
folding the laminated sheet to which the moisturizing agent has been applied to each of the plies;
characterized by comprising

In addition, the manufacturing method of the tissue paper product is
A method for producing a tissue paper product in which tissue paper made of a laminated sheet in which 3 or 4 plies are laminated is stored in a storage body,
Each ply contains a water-based humectant that exhibits hygroscopicity,
Each ply has a difference in arithmetic mean height Sa according to ISO 25718 between its two sides,
applying the moisturizing agent to each ply by a flexographic transfer printing method;
Applying the moisturizing agent to the outer surface of each ply located outside the laminated sheet while the outer surface of each ply has the smaller arithmetic mean height Sa;
folding the laminated sheet to which the moisturizing agent has been applied to each of the plies;
After that, it is stored in the storage body in a folded state;
characterized by comprising

According to the present invention, it is possible to provide a method for manufacturing a 3-ply or 4 -ply tissue paper and a method for manufacturing a tissue paper product, in which the necessary softness is secured and the stickiness of the outer surface is reduced.

FIG. 3 is a schematic cross-sectional view of a three-ply embodiment; FIG. 4 is a schematic cross-sectional view of a four-ply embodiment ; 1 is a schematic cross-sectional view of a conventional three-ply embodiment; FIG. 1 is a schematic cross-sectional view of a conventionally assumed four-ply embodiment; FIG . It is a photograph of an example of a surface coated with a chemical solution. It is a photograph of an example of a surface coated with a chemical solution. 1 is a schematic diagram of an example of obtaining a primary continuous sheet; FIG. FIG. 3 is a schematic diagram of a three-ply application example; FIG. 10 is a schematic diagram of another application example of 3-ply; FIG. 4 is a schematic diagram of a 4-ply application example; FIG. 4 is a schematic diagram of another application example of 3-ply; FIG. 10 is a schematic diagram of another application example of 4-ply; FIG. 11 is a schematic diagram of yet another application example of 4-ply; 1 is a schematic diagram of an example of spray coating equipment; FIG. 1 is a schematic diagram of an example of 3-ply coating by an example of spray coating equipment; FIG. FIG. 4 is a schematic diagram of another example application of three plies by an example spray application equipment; It is explanatory drawing of a folding form. FIG. 3 is a schematic perspective view of an example of storage in a storage box; FIG. 4 is a cross-sectional view of an example of storage in a storage box;

The present invention will be further described below while showing embodiments of the present invention.

Embodiments of tissue paper in which 3 or 4 plies are laminated will be described.
Because it is 3-ply or 4-ply instead of 2-ply, it gives a "fluffy and bulky feeling".

FIG. 1 showed a three-layer (1R, 2R, 3R) embodiment and FIG. 2 a four-layer (1R, 2R, 3R, 4R) embodiment. FIG. 3 shows a conventional three-layer (1R, 2R, 3R) embodiment , and FIG. 4 shows a conventional four -layer (1R, 2R, 3R , 4R ) embodiment .
In addition, a surface F coated with a moisturizing agent (hereinafter sometimes referred to as a “medicine” and having the same meaning) and a surface W not coated with the same are shown. Since there is a considerable gradient in the concentration of the moisturizing agent in the thickness direction from the applied surface F toward the non-applied surface W, the concentration gradient is illustrated as a gradation.

Each ply is applied with and contains a hygroscopic water-based humectant. The hygroscopic water-based humectant is a humectant containing polyol as a main component, particularly glycerin as a main component, that is, a humectant containing more than 50% by mass of glycerin, preferably 70% by mass or more of glycerin. can be used. Glycerin exhibits moisturizing and hygroscopic properties.

Liquid paraffin can be included to improve surface properties, especially smoothness. Also, 1,3-propanediol can be contained in an amount of 6.1% by mass or more and 12.6% by mass or less, if necessary.

The tissue paper may contain moisturizing agents such as glycerin as well as known auxiliary agents. Examples of auxiliary agents include moisturizing auxiliary ingredients such as sorbitol, hydrophilic polymer gelling agents, surfactants and softening agents to improve the retention of moisture in tissue paper, and aids in developing smoothness. oily components such as the aforementioned liquid paraffin, emulsifiers for stabilizing the moisturizing agents and improving coating properties, preservatives, antifoaming agents, and the like. In addition, the blending amount of ingredients such as moisturizing auxiliary ingredients and hydrophilic polymer gelling agents that increase moisture retention has an excessive effect on "fluffy and bulky feeling", "softness" and "surface smoothness". to the extent that it does not affect Specifically, it is 1.0% by mass or less, preferably 0.6% by mass or less, and more preferably 0.5% by mass or less.

The basis weight of one ply of the tissue paper of the present embodiment is desirably 15.0 to 22.5 g/m ² , particularly 15.5 to 20.5 g/m ² . When the basis weight of each layer is within this range, "softness" and "fluffy and bulky feeling" appear remarkably.
The higher the basis weight, the harder the paper, and the lower the basis weight, the softer the paper. Under this grammage, 3 -ply or 4-ply gives a remarkably "fluffy and bulky feeling". The basis weight is a value measured based on JIS P 8124 (1998).

The water-based moisturizing agent is substantially evenly contained in each ply. That is, when the moisturizing agent (medical solution) content ratio of the dry standard of the product is 100, the moisturizing agent (chemical solution) content ratio of each ply is in the range of 92.0 to 108.0. Desirably, each ply has a humectant (medicine) content on a dry basis within the range of 95.0 to 104.0.

As mentioned above, conventional moisturizing tissues (also called lotion tissues) require a certain amount of moisturizing agent to be applied in order for the user to feel soft during use. Therefore, since the moisturizing agent is not applied to the intermediate layers (2R in FIG. 3, 2R and 3R in FIG. 4) in the conventional embodiment shown in FIGS. This tends to cause the outer surface of the outer layer sheet to become sticky, which is not preferable.
On the other hand, in the tissue paper of the embodiment, unlike the conventional multi-layered tissue paper, the intermediate layer (intermediate ply) is also applied with a water-based moisturizing agent.
The advantage of this configuration is that the intermediate layer (intermediate ply), that is, (2R in FIG. 4, 2R and 3R in FIG. 5) also contains a water-based moisturizing agent, resulting in softness in the intermediate layer (intermediate ply). Therefore, the laminated sheet as a whole becomes soft.
As a result, the amount of moisturizing agent to be contained in the outer layer sheet can be reduced, and the stickiness due to the moisturizing agent on the outer surface of the outer layer sheet (the exposed surface of the laminated sheet) can be eliminated or suppressed.
In addition, this advantage is that when the moisturizing agent (medical solution) content on the dry basis of the product is 100, as long as the moisturizing agent (medical solution) content on the dry basis of each ply is within the above range, each ply It is developed substantially regardless of the basis weight of each ply and the content of the humectant in each ply.

In order to make the intermediate layer (intermediate ply) contain the water-based moisturizing agent, the moisturizing agent can be directly applied to the intermediate layer as well as the outer layer.
For example, when a moisturizing agent is applied to the outer layer sheet of the laminated sheet, the moisturizing agent applied to the outer layer sheet behaves so as to permeate and diffuse from the coated surface to the entire surface over time. However, the moisturizing agent applied to the outer layer sheet of the laminated sheet partially migrates to the adjacent sheet when the laminated sheet is subjected to external pressure such as calendering. However, when the applied amount of the moisturizing agent is small, the amount of the moisturizing agent transferred to the adjacent sheet is small.
On the other hand, when the amount of moisturizing agent applied is large, although the amount of moisturizing agent migrating to the adjacent sheet increases, there is a limit to the migration, and the moisturizing agent content of the outer layer sheet to which the moisturizing agent is applied and the adjacent sheet are large. There is a clear difference in height between the sheet and the moisturizing agent content.

Therefore, in order to make the intermediate layer (intermediate ply) also contain the moisturizing agent required to ensure softness, it is necessary to apply the moisturizing agent directly to the intermediate layer as well as the outer layer.
Conversely, if more moisturizer than necessary is applied to the outer layer sheet in order to transfer the moisturizer to the intermediate layer and ensure softness, a large amount of moisturizer will remain on the outer surface (exposed surface) of the outer layer sheet. and become sticky.
However, by applying the moisturizing agent directly to the intermediate layer (intermediate ply) as well, the amount of moisturizing agent applied to the outer surface (exposed surface) of the outer layer sheet can be reduced, and the occurrence of stickiness can be eliminated or suppressed.

It is common practice to crepe the ply base paper in order to give flexibility to the tissue paper. Also in the embodiment, creping is desirable.

The number of crepes is preferably 38 to 54/cm.
The number of crepes (crepes/cm) measured by one-shot 3D draws a linear shape in the MD direction, counts the number of peaks and valleys of 1.0 to 2.0 cm in the MD direction, and measures the length of the MD direction. It can be expressed as a value divided by the length.
When the shape is measured by one-shot 3D and the height profile on the XY plane is displayed on the screen, the height of the tissue paper surface is represented by color tone. The shape of the crepe in the height direction can be confirmed from the measured cross-sectional curve profile. Here, since the crepe has valleys in the direction perpendicular to the MD direction, the number of peaks of 1.0 to 2.0 cm in the MD direction is counted and divided by the measured MD length. say. The average value of the measured values at 5 points per sample is used as the value.
The degree of sharpness of the peaks of the unevenness “arithmetic mean curvature Spc of peaks” is desirably 2.8 to 3.5 (1/mm) (the larger the value, the sharper the fine protrusions on the surface).

Such creping makes the surface roughness different between one side and the other side of the ply base paper.

When the moisturizing agent is applied to the ply base paper, it is preferable to apply the moisturizing agent to the surface with small unevenness due to creping.
That is, in the ply whose surface roughness appears as a difference in the arithmetic mean height Sa according to ISO25718, it is desirable to apply the moisturizing agent to the surface having the small arithmetic mean height Sa.
When a moisturizing agent is applied to a surface having a small arithmetic mean height Sa, the surface having a small arithmetic mean height Sa and having a sufficient amount of the moisturizing agent present give a smooth feel to the touch. Along with it, it gives softness.

Since the outer layer contains a chemical solution, the laminated sheet is desirably calendered after the application of the moisturizing agent. As a result, the paper is smoothed by the external pressure on the outer surface of the outer layer, and the moisturizing agent applied spreads evenly over the surface, making the surface smoother and exhibiting further "smoothness of the surface."

The tissue paper coated with the moisturizing agent has an arithmetic mean height Sa of the outer surface (especially the exposed surface of the laminated sheet) under no pressure of 0.005 to 0.012 mm, particularly 0.006 to 0.008 mm. desirable. When the arithmetic mean height Sa is within the range, the surface is smooth and exhibits moderate unevenness, so that lipstick, foundation, etc. can be wiped off easily.
Here, "non-pressurized" means that the measurement is performed in the generated ("flexible") state.

Conversely, if a moisturizing agent is applied to the creped surface of the base paper ply, which has large unevenness due to the crepe process, the moisturizing agent is also hygroscopic. impair smoothness.

The arithmetic mean height Sa is defined in ISO25178, and represents the mean of the absolute values of the height difference of each point with respect to the mean plane of the surface in the defined region. The smaller the numerical value, the smaller the absolute value of the height difference of each point with respect to the average surface of the surface, indicating that the surface is flat, and the larger the numerical value, the rougher the surface.
In addition, when measuring the arithmetic mean height Sa of a tissue paper product in which a bundle of tissue paper is stored in the package in a pop-up manner, the measurement surface of the sample taken out of the tissue paper bundle is the surface with the crest side of the fold. (The same applies to the arithmetic mean curvature Spc of the summit point).

The tissue paper in the embodiment preferably has an arithmetic mean curvature (Spc) of 2.8 to 3.5 (1/mm) at the crest point of the outer surface under no pressure. The arithmetic mean curvature of the crest point represents the arithmetic mean of the principal curvatures of the crest point in the defined region. A smaller value indicates that the point of contact with another object is rounded, and a larger value indicates that the point of contact with another object is sharper.
In the case of a sample obtained from a pop-up type bundle, the measurement surface is the surface on which the crest of the fold is located. When the arithmetic mean curvature (Spc) of the peak points of the outer surface under no pressure is 2.8 to 3.5 (1/mm), the surface feels smooth and is excellent in wiping off lipstick, foundation, and the like.

"Arithmetic mean height Sa" and "arithmetic mean curvature of peak point (Spc)" in this specification are "one-shot 3D shape measuring machine VR-3200 (manufactured by Keyence Corporation)" (hereinafter referred to as "3D macroscope ”) and its equivalent (non-contact three-dimensional measuring device).
The "3D microscope" can measure the shape of an object from a fringe projection image projected on a monochrome C-MOS camera by structured illumination light emitted from the light projection part. The projected image can be used to measure the height, length, angle, volume, etc. of any part. The software "VR-H2A" and its equivalent software can be used for observation, measurement and image analysis of images obtained by the "3D microscope". The measurement conditions are a visual field area of 24 mm×18 mm and a magnification of 12 times.

A specific procedure for measuring the arithmetic mean height (Sa) and the arithmetic mean curvature (Spc) of the outer surface under no pressure is as follows.
On the measuring table, a ply tissue paper (about 50 mm in the MD direction × 50 mm in the CD direction) to be a sample is placed in a raw state with the measuring machine facing the front and the depth direction in the MD direction. Place. The flat portion of the product shall be used as the test piece for measurement.
By operating the screen of the software ("VR-H2A"), three images of the sample surface, the main image (texture), the main image (height), and the 3D image, are obtained. Next, the "texture" image displayed by selecting "surface roughness" in the software is converted into a "height" image (an image represented by color-coded shades in the height direction). do.
Next, measurement is performed by setting at least the maximum height (Sz), the arithmetic mean height (Sa), and the arithmetic mean curvature (Spc) of the summit point as measurement parameters. The size of the measurement range shall be 3.0 mm×3.0 mm. With the above software, the measurement range can be set by selecting "numerical designation" in "addition of area". The measurement range is set so that the embossed portion is not included in the measurement range, and furthermore, the gradation of the color tone in each measurement range on the screen is nearly constant by visual observation.
Check the measured maximum height (Sz), arithmetic mean height (Sa), and arithmetic mean curvature (Spc) at the summit point, and if the maximum height (Sz) exceeds 0.1000 mm Alternatively, discard the value and set another measurement range. The maximum height (Sz), the arithmetic mean height Sa, and the arithmetic mean curvature of the summit point (Spc) are surface roughness parameters defined in ISO25178. In addition, in order to remove large waviness of the sheet, the measurement is performed under the following conditions: the filter has a Garcian correction, the S-filter is not used, the F-operation is a two-dimensional curved surface, the L-filter is 0.8 mm, and the terminating process is on.
Planar roughness measurement of "maximum height (Sz)", "average arithmetic roughness (Sa)", and "arithmetic mean curvature of peak point (Spc)" is performed in the measurement range of 3.0 mm square. The plane roughness measurement in the range of 3.0 mm square in this image is performed at a total of 5 locations by changing the position, and the average value of the 5 locations is the "maximum height (Sz)" and "average arithmetic roughness of the measurement sample. (Sa)” and “arithmetic mean curvature of summit point (Spc)”. The 3.0 mm square range, which is the measurement range, is located in the central portion where distortion is small in the visual field area of 24 mm×18 mm. In addition, the selection of each of the above five measurement ranges, the "maximum height (Sz)", the "average arithmetic roughness (Sa)", and the "arithmetic mean curvature of the summit point (Spc)" may be measured at the same time. , may be measured by changing the range Z to be measured.

The content of the moisturizing agent in each ply is 10.0 to 35.0% by mass . In particular, it is desirable to be 17.0 to 30.0% by mass . If the content is too small, the softness is not sufficient, and if the content is too high, the exposed surface becomes sticky and the strength of the paper tends to decrease.

It is preferable that the tissue paper is laminated with 3 plies, and the basis weight of 1 ply is 15.0 to 22.5 g/m ² and the thickness of 3 plies is 140 to 270 μm, particularly 176 to 230 μm. In a multi-ply structure such as 3-ply, the paper thickness tends to affect especially "softness" and "fluffiness". With the tissue paper of the present embodiment, when the paper thickness is within this range, "softness", "fluffy and bulky feeling", and "surface smoothness" are remarkable.

In the case of tissue paper in which 4 plies are laminated, it is desirable that the basis weight of 1 ply is 15.0 to 22.5 g/m ² and the paper thickness of 4 plies is 180 to 360 μm, particularly 220 to 320 μm.

Paper thickness is measured using a dial thickness gauge (thickness measuring instrument) "PEACOCK G type" (manufactured by Ozaki Seisakusho) under the same conditions after sufficiently conditioning the humidity of the test piece under the conditions of JIS P 8111 (1998). value. Specifically, after confirming that there is no dust or dust between the plunger and the measuring table, lower the plunger on the measuring table, move the memory of the dial thickness gauge to adjust the zero point, and then , Raise the plunger, place the test piece on the measuring table, lower the plunger slowly, and read the gauge at that time. At the time of measurement, care is taken so that the terminal of the metal plunger (a circular plane with a diameter of 10 mm) hits perpendicularly to the plane of the paper. Note that the load at the time of this paper thickness measurement is about 70 gf. The paper thickness is the average value of the measured values obtained by performing this measurement 10 times at different sites. A test piece is taken from a 3-ply product sheet and measured while avoiding creases, contact embossed portions, and the like.

The tissue paper of this embodiment preferably has a dry strength of 220 to 420 cN/25 mm with 3 plies or 4 plies in the longitudinal direction. When the dry strength in the longitudinal direction is within this range, "softness", "fluffy and bulky feeling" and "surface smoothness" are remarkable. In addition, it is in the range of sufficient strength to withstand use.
If the dry strength of three plies in the machine direction is excessively high, i.e., if a ply base paper is used in which the fibers are arranged densely in the machine direction and compacted under high pressure, the softness will be poor and the moisturizing agent will be trapped between the fibers. The exposed surface tends to be sticky due to the (expected) lack of penetration.

Also, the dry strength of 3 plies or 4 plies in the horizontal direction is desirably 60 to 160 cN/25 mm. When the dry strength in the lateral direction is within this range, "softness", "fluffy and bulky feeling" and "surface smoothness" become remarkable. In addition, it is in the range of sufficient strength to withstand use.
Furthermore, although it is not clear, the "transverse dry tensile strength" does not affect the individual functionalities such as "softness" and "fluffiness", but the general functionalities such as "feel". Instead of specific evaluation criteria such as "softness" and "fluffy feeling", the tissue paper was evaluated as good or bad based on the overall evaluation criteria of "touch" after letting the subject freely touch the sample. It has been found that there is a certain correlation between the evaluation of "feel on the skin" and the "lateral dry strength".

Further, the tissue paper of this embodiment preferably has a wet paper strength of 50 to 90 cN/25 mm with 3 plies or 4 plies in the horizontal direction.
The ratio of wet transverse tensile strength/dry transverse tensile strength is desirably between 0.62 and 0.76. In addition, this value is a measured value with 3 ply as it is. Due to such a difference in strength, the user feels "sturdiness (strength and sense of security)" in a mode of use that changes from dry to wet, such as when chewing. In addition, changes in the strength of the paper in such usage conditions are less perceptible, affecting the perception of "smoothness" during use.
Note that the longitudinal direction of paper is also called the MD direction, and is the direction of flow during papermaking. The transverse direction of paper is also called the CD direction, and is the direction orthogonal to the machine direction (MD direction) during papermaking.

Moreover, the dry (tensile) strength of the tissue paper of the embodiment is a value measured based on JIS P 8113, and is a value measured as follows. A test piece cut into a width of 25 mm (±0.5 mm) and a length of about 150 mm in both the vertical and horizontal directions is used. Tissue paper is measured as multiple plies. As a tester, a load cell tensile tester TG-200N manufactured by Minebea Co., Ltd. or a device equivalent thereto is used. The gripping distance is set to 100 mm, and the pulling speed is set to 100 mm/min. Measurement is performed by clamping both ends of the test piece to the grips of the tester, applying a tensile load to the piece of paper in the vertical direction, and reading the indicated value (digital value) when the paper breaks. Five sets of specimens were prepared for each of the longitudinal and transverse directions, and measurements were made five times each, and the average of the measured values was taken as the dry tensile strength in each direction. Sample preparation is according to JIS P 8111 (1998).

Moreover, the wet (tensile) strength of the tissue paper in the embodiment is a value measured according to JIS P 8135 (1998), and is a value measured as follows. A test piece cut into a width of 25 mm (±0.5 mm) and a length of about 150 mm in both the vertical and horizontal directions is used. If the tissue paper has multiple plies, measure the multiple plies as they are. As a tester, a load cell tensile tester TG-200N manufactured by Minebea Co., Ltd. or a device equivalent thereto is used. The gripping distance is set to 100 mm, and the pulling speed is set to 50 mm/min. The test pieces are cured in a drier at 105° C. for 10 minutes. After clamping both ends of the test piece to the grips of the tester, use a flat brush soaked with water to apply water horizontally to the center of the test piece with a width of about 10 mm, and then immediately vertically to the paper piece. Apply a tensile load to the paper and read the indicated value (digital value) when the paper breaks. Five sets of samples are prepared for each of the longitudinal direction and the transverse direction, and measurements are made five times each, and the average of the measured values is taken as the wet tensile strength in each direction.

Dry tensile strength and wet tensile strength can be adjusted by internally adding a dry paper strength agent or a wet paper strength agent to the stock or wet paper. As the dry paper strength enhancer, starch, polyacrylamide, CMC (carboxymethylcellulose) or salts thereof such as carboxymethylcellulose sodium, carboxymethylcellulose calcium, carboxymethylcellulose zinc and the like can be used. Polyamide polyamine epichlorohydrin resins, urea resins, acid colloid/melamine resins, heat-crosslinkable coated PAM, and the like can be used as wet paper strength agents. When the dry paper strength enhancer is internally added, the amount added to the pulp slurry is about 1.0 kg/ton of pulp or less. The wet paper strength enhancer is desirably cationic, and the amount added to the pulp slurry is about 5.0 to 20.0 kg/ton of pulp.

The fibrous material constituting the tissue paper is pulp fiber, preferably NBKP (softwood kraft pulp) and LBKP (hardwood kraft pulp) used for tissue paper. Although waste paper pulp may be blended, it is extremely desirable that waste paper pulp is composed only of virgin pulp NBKP and LBKP, since it is difficult to develop "softness" with waste paper pulp. The mixing ratio is NBKP:LBKP=25:75 to 40:60 in mass ratio. Within this range, it is possible to feel the "softness" and "smoothness" remarkably while feeling the "fluffy and bulky feeling" and the paper strength necessary for smoothness.

A compression work of 1.85 to 2.50 gf/cm/cm ² , particularly 2.18 to 2.35 gf/cm, for a total of 12 plies of 4 sets of 3 plies or 12 plies of 3 sets of 4 plies. /cm ² is preferred.
Furthermore, it is desirable that the compression recovery is 46.0 to 54.5%, particularly 48.0 to 53.0%.

[Method for manufacturing tissue paper]
The tissue paper according to the present embodiment and the tissue paper product in which the tissue paper is bundled and housed in the package can be manufactured by the following manufacturing procedure.

First, a primary stock roll JR (also referred to as a jumbo roll) is manufactured in the following manner using the papermaking equipment example X2 shown in FIG.

A paper stock prepared in advance by adding suitable chemicals to the pulp slurry from the head box 31 is supplied onto the wire 32w of the wire part 32 to form the wet paper web W (forming step), and then the wet paper web W is pressed. After being transferred to the felt 34 of the part 33, it is nipped and dewatered by a pair of dewatering rolls 34 and 35 (dewatering step).

Next, the dehydrated wet paper is adhered to the surface of the Yankee dryer 36, dried, and then scraped off by the doctor blade 37 to form a dried base paper S1 having a crepe (a primary continuous sheet to be described later) (creping/drying step). .

Then, the dry base paper S1 is wound by a winding means 38 having a winding drum 39 so that the back surface of the dry base paper S1 faces the shaft side of the primary web roll JR (as the winding inner surface). to be the primary roll JR (primary roll winding step).

The primary stock roll JR generally has a diameter of 1,000 to 5,000 mm, a length (width) of 1,500 to 9,200 mm, and a winding length of 5,000 to 80,000 m.

A calendering process (not shown) may be provided for the dry base paper S1 scraped off by the doctor blade 37 prior to the primary roll-up process, and the front and back surfaces thereof may be smoothed.

Here, the back surface of the dry base paper S1 means the surface opposite to the surface that was in contact with the cylinder of the Yankee dryer 36 . Although it depends on the presence or absence of the calendering process, generally the mirror-finished surface in contact with the Yankee dryer is smoother and has better surface properties.
As described above, at least the outer surface (exposed surface) of the outer layer of the laminated sheet is the surface (smooth and excellent in surface property) that was in contact with the mirror surface Yankee dryer, and this smooth and excellent surface is Apply moisturizer to it. This allows the outer surface (exposed surface) of the outer layer to have a small arithmetic mean height Sa according to ISO25718.
As a result, the laminated sheet provides the consumer with a smooth, soft feel.

Here, the primary continuous sheet S1 (ply base paper) constituting the primary base roll JR specifically has a basis weight according to JIS P 8124 of 10 to 25 g/m ² , preferably 12 to 20 g/m ² , or more. Preferably, it is 13-16 g/m ² . If the basis weight is less than 10 g/m ² , it is preferable in terms of the softness of the tissue paper 1, but it becomes impossible to ensure proper strength. On the other hand, if the grammage exceeds 25 g/m ² , the tissue paper 1 becomes too hard and has a poor texture.

Further, the primary continuous sheet S1 has a crepe ratio of 10 to 30%, preferably 12 to 25%, more preferably 13 to 20%. When the crepe rate is less than 10%, the tissue paper 1 is easy to break in the subsequent processing and has little elongation and lacks stiffness. On the other hand, if the crepe ratio exceeds 30%, it becomes difficult to control the tension of the sheet during processing, and the paper tends to be broken. becomes easier.

[Ply process [secondary raw roll manufacturing method and manufacturing equipment]]
Three primary rolls JR produced in the papermaking process (four in the case of 4-ply) are set in a lamination facility called a ply machine, and a single layer is formed from each primary roll. A continuous sheet is fed out, and a moisturizing agent is applied, for example, according to the application mode described later.

In the case of 3-ply, a moisturizing agent is applied to each of the continuous single-layer sheets, or a continuous single-layer sheet is laminated into two layers, and then a moisturizing agent is applied from both sides of the two layers. For apply moisturizer in a single layer.
In the case of 4-ply, a moisturizing agent is applied to each of the single-layer continuous sheets, or a single-layer continuous sheet is superimposed on two layers, and then a moisturizing agent is applied from both sides of the two layers. After stacking two layers of continuous single-layer sheets, a moisturizing agent can be applied from both sides of the two layers.

(Calendar processing)
After applying the humectant , the laminated continuous sheet can be calendered.
The type of calender is not particularly limited, but a soft calender or a chilled calender is preferred for the purpose of improving surface smoothness and adjusting paper thickness. A soft calender is a calender using rolls coated with an elastic material such as urethane rubber, and a chilled calender is a calender made of metal rolls.

The number of calendar parts can be changed as appropriate. If a plurality of devices are installed, there is an advantage that sufficient smoothing can be achieved even if the processing speed is high.
The type of calendering, nip line pressure, number of nips, etc. in calendering are also used as control factors for papermaking, and these control factors are preferably changed as appropriate according to the desired tissue paper quality, ie, paper thickness and surface properties.

Thereafter, if necessary, embossing can be carried out in order to integrate the laminated sheet and to impart designability.

(Folding process)
A folding step is preferably provided after the step of applying the moisturizing agent or following the calendering step.
In this folding step, the obtained laminated sheet is sequentially placed in a known folding facility, also called a rotary interfolder (not shown), as shown in FIG. Then, one side of the preceding laminated sheet S1 and one side of the succeeding laminated sheet S3 are folded and laminated as a bundle.

(packaging process)
The bundle of laminated sheets is cut into short bundles of a predetermined length, and the bundles of short laminated sheets are stored in a packaging body (paper packaging box, plastic packaging bag, etc.), and when used, can be removed from the packaging body. A pop-up system is used so that the laminated sheets can be taken out from the package one by one.

[Moisturizer application form]
The moisturizing agent can be applied by a roll transfer device such as a flexographic printing machine or a gravure printing machine, a spray coating device, or the like.

Flexographic printing or spray coating is particularly preferred when applying a water-based moisturizing agent (chemical solution) containing glycerin, which exhibits hygroscopicity, as a main component, and when applying to a sheet traveling at high speed.

Also in the embodiment, a flexographic printing method can be adopted.
If the chemical solution is applied by the flexo printing method, it has the advantage that the printing plate roll (transfer roll) is made of resin and the application amount can be stabilized even if the processing speed is high because it is made of resin, and the amount of application can be stabilized according to the unevenness of the crepe paper. By changing the line number and cell capacity of the roll, and the line number and vertex area ratio of the flexographic printing plate roll, there are advantages such as being able to easily handle a wide range of chemical viscosities and to stabilize the coating amount.

In addition, it is preferable that the chemical application in the chemical application step is performed by a flexographic printing method using a doctor chamber. In the doctor chamber method, a chemical solution is applied directly to the surface of an anilox roll (concave roll for transfer) to create a film. In addition, since the chemical solution transferred from the anilox roll is uniform, it can be suitably applied even in the case of a small amount of application.

(Flexographic printing)
An example in which a flexographic printing machine is used as the chemical applying means 90 in the chemical application process is illustrated. When applying a chemical solution to the laminated continuous sheet, it is particularly desirable that the material of the flexographic printing plate roll is silicone rubber.
The line number of the flexographic printing plate roll is 10 to 60 lines, preferably 15 to 40 lines, particularly preferably 20 to 35 lines. If the number of lines is less than 10 lines, the coating tends to be uneven.

The number of lines of the anilox roll is 10 to 300 lines, preferably 25 to 200 lines, particularly preferably 50 to 100 lines. If the number of lines is less than 10 lines, the coating tends to be uneven. The cell capacity of the anilox roll is 10-100 cc, preferably 15-70 cc, particularly preferably 30-60 cc. If the cell volume is less than 10 cc, the desired coating amount cannot be obtained, while if the cell volume exceeds 100 cc, the amount of the chemical solution that scatters increases.

Here, it is important that the chemical solution can be applied stably in the chemical solution application step, and the number of lines of the printing plate roll and the anilox roll is important in terms of operational stability. As a system for transferring the chemical liquid stored in the storage tank to the anilox roll, an appropriate method such as a doctor chamber system or a touch roll system is adopted. Detailed examples of forms adopting each of these flexographic printing methods

<Embodiment example of doctor chamber system>
In a doctor chamber type flexographic printing machine 90 for flexographic printing, a doctor chamber 92 containing a chemical solution is arranged to face a rotatable anilox roll 93, and the chemical solution is transferred from the doctor chamber 92 to the anilox roll 93B. It's becoming A printing plate (transfer) roll 94 is rotatably installed in contact with the anilox roll 93 and in contact with the sheet S1 or S2, and the chemical solution is transferred from the anilox roll 93 to the printing plate roll 94. .
Then, a chemical solution is applied from the printing plate roll 95 to the laminated continuous sheet while applying pressure between the printing plate roll 94 and the elastic roll 95 facing the sheet S1 or S2.
As will be described later, when the elastic roll 95 is used and when it is not used, the printing plate (transfer) roll 94 is opposed and pressure is applied between them, and the lamination is continuously performed from the printing plate roll 95. A chemical solution can also be applied to the sheet.

The amount of moisturizing agent applied is preferably controlled based on the degree of difference in peripheral speed between the anilox roll 93 and the printing plate roll 94, since the amount of moisturizing agent applied can be controlled during the operation. For example.

<3-ply first moisturizing agent application form>
Various forms can be adopted for the moisturizing agent application form.
The example of FIG. 8 shows a 3-ply moisturizing agent application form, and the single-layer sheets fed out from the three primary rolls consist of a two-layer sheet S2 that joins two layers in the middle and a single layer sheet S2 that is left as it is. Sheets S 1 are fed to a coating device having three flexographic presses 90 .
A chemical solution is applied to each outer surface of the two-layer sheet S2. The chemical solution is also applied to the outer surface of the single-layer sheet S1.
The two-layer sheet S2 and the single-layer sheet S1 are merged at the junction 50 to form a three-layer laminated sheet S3. After that, as described above, it is led to the interholder through calendering and embossing.
Here, according to the present invention, in order to apply a moisturizing agent (medical solution) to the outer surface of each ply positioned on the outer side of the laminated sheet S3 while the outer surface of each ply has a small arithmetic mean height Sa, , the arrangement of the sheets can be considered, and a three-layer laminated sheet as shown in FIG. 1 can be obtained.

FIG. 9 shows a 3-ply moisturizing agent application form, in which the single-layer sheet fed out from the three primary rolls joins the 3-layer sheet on the way, and in the separation section 51, the 2-layer sheet S2 and the , and the single-layer sheet S1 and fed to a coating device having three flexographic printing presses 90. In FIG.
A chemical solution is applied to each outer surface of the two-layer sheet S2. After that, it joins with the single-layer sheet S1 at the merging section 50 to form a three-layer sheet. After that, another flexographic printing machine 90 applies a chemical solution to the outer surface of the single-layer sheet S1 to form a three-layer laminated sheet S3. be done.

<4-ply first moisturizing agent application form>
FIG. 10 shows a 4-ply moisturizing agent application form, in which two single-layer sheets fed out from four primary rolls join together as a two-layer sheet on the way, and each outer layer of the two-layer sheet S2 is formed. Liquid is applied to the sides.
Similarly, the other two single-layer sheets join together as a double-layer sheet in the middle, and the chemical solution is applied to each outer surface of the double-layer sheet S2.
After that, the two-layer sheets S2 are joined together at the junction 50 to form a four-layer laminated sheet S4.

<Second moisturizing agent application form>
A sheet coated with a water-based humectant (medicine) containing lycerin, which exhibits hygroscopicity, as a main component tends to stretch and lose strength.
When this application is performed at a particularly high speed, in the first moisturizing agent application mode, there is a so-called free run portion where the sheet is not constrained by anything between application positions.
As a result, the sheet coated with a water-based moisturizing agent (medical solution) is stretched and its strength is lowered, resulting in paper breakage.
On the other hand, in the second moisturizing agent application form, that is, at least each sheet is in contact with a roll traveling at the same speed as the sheet in the process from the chemical solution application position to the 3-ply lamination position. It is desirable to use a coating form that

<3-ply second moisturizing agent application form>
FIG. 11 shows a second three-ply humectant application form example, in which each flexographic printing press 90 is not provided with elastic rolls 95 as in the first humectant application form example.
Instead, the sheet is nipped between the printing plate (transfer) roll 94 of the first flexographic printing press 90A and the printing plate (transfer) roll 94 of the second flexographic printing press 90B, and the second flexographic printing press 90B and a printing plate (transfer) roll 94 of the third flexographic printing press 90C to nip the sheet.
The two-layer sheet S2 is coated with a chemical solution from both sides by a first flexographic printing machine 90A and a second flexographic printing machine 90B, and then the outer surface of the single-layer sheet S1 is coated with a chemical solution by a third flexographic printing machine 90C. .

<Second 4-ply moisturizing agent application form>
FIG. 12 shows an example of a second 4-ply moisturizing agent application form. The sheet is nipped with the transfer) roll 94, and the sheet is nipped with the printing plate (transfer) roll 94 of the second flexographic printing press 90B and the printing plate (transfer) roll 94 of the third flexographic printing press 90C. The sheet is nipped between the printing plate (transfer) roll 94 of the third flexographic printing press 90C and the printing plate (transfer) roll 94 of the fourth flexographic printing press 90D.
The two-layer sheet S2 is coated with a chemical solution from both sides by a first flexographic printing machine 90A and a second flexographic printing machine 90B. 3 A chemical solution is applied by the flexographic printing machine 90C and combined to form a four-layer S4.

FIG. 13 shows an example of a second 4-ply moisturizing agent application form. The sheet is nipped between the printing plate (transfer) roll 94 of the second flexographic printing press 90B and the printing plate (transfer) roll 94 of the fourth flexographic printing press 90D. The sheet is nipped between the printing plate (transfer) roll 94 of the second flexographic printing press 90B and the printing plate (transfer) roll 94 of the third flexographic printing press 90C.
At these nip positions, a chemical solution is applied to both surfaces of the two-layer sheet S2, the single-layer sheet S1 serving as the intermediate sheet, and the single-layer sheet S1 serving as the outer layer sheet.

<Third moisturizing agent application mode>
Spray application is also possible as a third moisturizing agent application form.
For spray coating, specifically, a nozzle type spraying method, a rotor dampening spraying method, or the like can be adopted. The types of spray nozzles in the nozzle-type spraying method include an empty cone nozzle that sprays in an annular shape, a full cone nozzle that sprays in a circular shape, a full pyramidal nozzle that sprays in a square shape, a full rectangular nozzle, and a fan nozzle. Nozzle diameter, nozzle number, nozzle arrangement pattern, nozzle arrangement number, or spray distance, spray pressure, spray angle, and spray so that the chemical solution is sprayed uniformly in the width direction of the secondary continuous sheet The concentration, viscosity, etc. of the liquid can be appropriately selected for use.

As for the method of atomization in the nozzle type spray device, it is possible to select and use two types of methods, one-fluid method and two-fluid method. Of these, the one-fluid spraying method uses compressed air to directly apply pressure to the sprayed chemical solution, and sprays mist droplets from the nozzle, or air is injected into the nozzle through fine holes in the side of the nozzle near the ejection port. It is a system that sucks and sprays mist droplets. In addition, the two-fluid spray method is an internal mixing type that mixes and atomizes the liquid that sprays compressed air inside the nozzle, an external mixing type that mixes and atomizes the liquid that sprays compressed air outside the nozzle, and atomizes A method such as a collision type in which droplet particles are caused to collide with each other to further homogenize and finely atomize the droplet particles is exemplified.

On the other hand, in the rotor dampening spray method, the liquid to be sprayed is sent onto a disk that rotates at high speed, and the liquid is atomized by the centrifugal force of the disk. The amount of sprayed liquid (applied amount) is controlled by changing the amount of liquid sent onto the disk. It is. The rotor dampening applicator can uniformly apply a small amount of spray liquid to the surface of pigment-coated paper while suppressing the scattering of mist droplets. It has certain advantages.

FIG. 14 is an example of a rotor dampening spray device 100 . In this apparatus, a rotating rotor 100A is provided in a cover storage chamber (not shown) that is provided as required, and a chemical liquid is sprayed onto the laminated continuous sheet from jet nozzles 100B of the rotating rotor.

15 and 16 show how the rotor dampening spray apparatus 100 is used to obtain a three-ply laminated sheet.
Without further elaboration, the application form will be readily apparent.

A bundle of tissue paper folded and laminated by an interholder, for example, a rotary interholder, is stored in a packaging body, such as a paper packaging box or a film container, according to a conventional method.
18 and 19 show the tissue paper product X1. A bundle 10 of tissue papers in which a plurality of laminated tissue papers 1 are folded and layered is stored in a storage box in which an outlet or an outlet forming part is formed on the upper surface 2 0 U, and when used, the outlet is used. When one sheet of the tissue paper 1 is taken out, a part of one sheet of the adjacently laminated lower layer is exposed from the take-out port.

[Storage box]
The storage box in which the bundle 10 of tissue paper 1 is stored is a cuboid-shaped box that is also called a carton box. This storage box has a product appearance, and includes a paper box 20 having an annular perforation line 25 as an outlet forming part on the upper surface 20U, and a resin-made paper box covering the area surrounded by the perforation line 25 from the inside of the paper box. a film 22;

The tissue paper 1 stored as a bundle in the storage box is taken out one by one through the slit 24 from the take-out port . A portion of the tissue paper exposed from the outlet is supported by the slit 24 and prevented from falling into the carton box.

A bundle 10 of the tissue papers 1 is formed by folding the tissue papers 1 and stacking them. More specifically, as can be understood from FIG. 17 , the rectangular tissue paper 1 is substantially folded in two, and the edges of the folded pieces are positioned on the folded inner surfaces of the vertically adjacent tissue papers. , are alternately stacked. Here, the term "substantially" means that the edges formed in manufacturing are allowed to fold back slightly.

In the bundle 10 of the tissue paper 1 of this laminated structure, when one folded piece positioned at the top is pulled upward, another adjacent folded piece immediately below it is dragged upward by friction and lifted. be done. A bundle 10 of tissue paper 1 having such a structure is stored with its uppermost surface facing the upper surface of a storage box having an outlet , etc. When one sheet (the one located on the uppermost surface) is pulled out, a part of the other sheet located immediately below is exposed. Although the number of laminated tissue papers 1 in the present invention is not limited, the typical number of laminated sheets of this type of product is 120 to 240 sheets.

The interfolder that performs the folding process may be a multi-stand type, a stand type, or a folded plate type, in addition to the rotary interholder described above, or may be a facility that performs folding using a folded plate, or is also called a rotary type. It may be a facility that performs the folding process with a pair of folding rolls.
In embodiments, a rotary interfolder is preferably employed. In the case of tissue paper products with a multi-ply structure of 3 or more plies, the number of layers is large and each layer tends to be misaligned. For this reason, the layers are less likely to be misaligned, and the folding quality is likely to be good. Therefore, the "fluffy feeling" is less likely to deteriorate particularly during processing.

Further, it is desirable to calender the laminated sheet. By subjecting the laminated sheet to calendering, it becomes easier to create a difference in paper thickness between the outer layer and the middle layer. In particular, when folding is performed using a rotary interfolder, it is desirable to apply a moisturizing agent within the interfolder. Furthermore, if the first calendering process is performed before applying the moisturizing agent, and the second calendering process is performed after applying the moisturizing agent, "soft and bulky feeling" can be felt, while "softness" can be felt. And it is easy to make a tissue paper that makes you feel "smoothness" remarkably.

By the way, the reason why the "arithmetic mean roughness Sa", "compression work" and "compression recovery" of the surface measured by one-shot 3D are suitable for "tissue off" is roughly , can be considered as follows.
A small value of "arithmetic mean roughness Sa" gives a smooth surface.
High values of "compression work" give good softness due to the fast and long compression onset phase.
A small value of "compression recovery" means that once it is pushed in, it is difficult to return to its original state, which improves the controllability of pressure and contributes to making it easier to control the amount of force applied to wipe off lipstick or foundation. .
"smoothness" is expressed.

Samples of the tissue paper of the embodiment and the conventional tissue paper were prepared, and the following sensory test was performed as an evaluation item for each item in the sensory test column. The physical property values, composition values, etc. of each sample were measured as follows. Physical property values, composition values and test results of each sample are as shown in Tables 1 and 2 for 3-ply, and Tables 3 and 4 for 4-ply.

[Basis weight]
It was measured according to JIS P 8124 (1998).
[Paper thickness]
As described above, under the conditions of JIS P 8111 (1998), the thickness was measured using a dial thickness gauge (thickness measuring instrument) "PEACOCK G type" (manufactured by Ozaki Seisakusho) according to the above-described thickness measurement method.

[Dry tensile strength]
It is a value measured based on JIS P 8113 and is a value measured as follows. A test piece cut into a width of 25 mm (±0.5 mm) and a length of about 150 mm in both the vertical and horizontal directions is used. Tissue paper is measured as multiple plies. As a tester, a load cell tensile tester TG-200N manufactured by Minebea Co., Ltd. or a device equivalent thereto is used. The gripping distance is set to 100 mm, and the pulling speed is set to 100 mm/min. Measurement is performed by clamping both ends of the test piece to the grips of the tester, applying a tensile load to the piece of paper in the vertical direction, and reading the indicated value (digital value) when the paper breaks. Five sets of specimens were prepared for each of the longitudinal and transverse directions, and measurements were made five times each, and the average of the measured values was taken as the dry tensile strength in each direction.

[Wet Tensile Strength]
It was measured according to the tensile test of JIS P 8135 (1998).
A test piece was cut into a width of 25 mm (±0.5 mm) and a length of about 150 mm in both vertical and horizontal directions. In the case of multiple plies, the tissue paper was measured as it was. As a tester, a load cell tensile tester TG-200N manufactured by Minebea Co., Ltd. was used. The grip interval was set to 100 mm. The measurement was performed by clamping both ends of the test piece that was cured for 10 minutes in a dryer at 105 ° C. to the grips of the tester, then using a flat brush soaked with water, and about 10 mm in the center of the test piece. Water was applied horizontally across the width, and then a tensile load was immediately applied to the piece of paper in the vertical direction, and the indicated value (digital value) was read when the paper broke. The tensile speed was set to 50 mm/min. Five sets of samples were prepared for each of the longitudinal direction and the transverse direction, and measurements were made five times each, and the average of the measured values was taken as the wet tensile strength in each direction.

[Softness]
It was measured according to the handle o-meter method according to JIS L 1096 E method. However, the size of the test piece was 100 mm×100 mm, and the clearance was 5 mm. One ply was measured 5 times each in the vertical direction and the horizontal direction, and the average value of all 10 times was expressed in units of cN/100 mm. Softness is one of the indices of softness.

[MMD]
While the contact surface of the friction element is brought into contact with the surface of the measurement sample to which a tension of 20 g/cm is applied in a predetermined direction with a contact pressure of 25 g, it is moved at a speed of 0.1 cm/cm in substantially the same direction as the direction in which the tension is applied. s, and the coefficient of friction at this time is measured using a friction tester KES-SE (manufactured by Kato Tech Co., Ltd.). The MMD is the value obtained by dividing the friction coefficient by the friction distance (movement distance=2 cm). The friction element has a contact surface formed by adjoining 20 piano wires P having a diameter of 0.5 mm and having a length and a width of 10 mm. It is assumed that the contact surface is formed with a unit bulging portion whose tip is formed of 20 piano wires P (with a radius of curvature of 0.25 mm).
In the MMD measurement, the contact embossed portion and the wrinkled portion should not be included in the measurement in advance.

On the other hand, the sample to be measured is the average value obtained by taking one set each of an arbitrary odd number from the top, center and bottom of the bundle of laminated sheets and measuring them. The three-layer (three-ply) sheet has a first layer (outer layer), a second layer (middle layer), and a third layer (outer layer) from the bottom side of the sheet.

Note 1 in the table (judgment of chemical solution application surface): Two test pieces cut into 2 cm squares from each sheet are floated on a spoon with the front and back sides facing up in water, and after 30 seconds, the moisture on the test piece is low. One is the coated surface (notation "CT") and the other is the non-coated surface (notation "NCT"). If the coated surface is not clear, it is indicated as "-".

Note 2 in the table is the value obtained by surface roughness measurement measured by one-shot 3D

[Sensory test]
Based on Comparative Example 2, the evaluation was set to "4.0", and the average value of the ratings of 1 to 7 grades by 12 evaluators. The higher the score, the higher the evaluation.

Comparative Examples 1 to 4 are commercial products in China. The reference example is a prototype made by the applicant.

According to the above results, it is possible to obtain a 3-ply or 4- ply tissue paper with reduced stickiness on the outer surface while ensuring the required softness.

In the above experimental example, the determination of the surface to which the chemical solution is applied is simply performed, but it has been found that it is desirable to perform the determination in more detail as follows.
(1) Prepare a pan containing 500 mL of water, a spoon, and a sample.
(2) A 3-layer or 4-layer laminated sheet is cut into 2 cm×2 cm pieces, excluding embossed or wrinkled portions, and each piece is divided into each sheet (3 sheets, 4 sheets).
(3) The valley side of each divided sheet is A side (test piece A), and the back side is B side (test piece B). Mark side A with a red ballpoint pen.
(4) Place the test piece A with the A side up and the test piece B with the B side up on each sheet on a spoon (about 20 cm in length) for medicine.
(5) The test piece A and the test piece B are placed in a pan at the same time and gently floated on the surface of the water.
(6) After 30 seconds, the state of the water film on the test piece and the state of light reflection are visually observed (photograph).
(7) The side (test piece) of the surface of the test piece which clearly reflects a lot of water is defined as the chemical non-applied surface (NCT), and the opposite surface (test piece) is defined as the chemical applied surface (CT).
(8) Judgment by visual observation (photograph), and when there is no clear difference, both sides are marked with "-".

Test examples are shown in FIGS. 5 and 6. FIG.
Looking at the case of FIG. 5 for test piece A, the surface being viewed is A surface = the chemical solution applied surface, and water is wet from the back surface, but the water on the upper surface (A surface = chemical solution applied surface) is exposed. There are few parts. Moisture passing through the gaps (pores) of the paper from below reaches the upper surface, but it is considered that the chemical solution has a low surface tension and therefore does not easily spread over the upper surface.
On the other hand, if we focus on the case of FIG. 6 for test piece B, the side we are looking at is B side = non-chemical coated side, water is wetted from the back side, and the upper side (B side = non-chemical coated side) A lot of the water is exposed. It is thought that the water that has passed through the gaps (pores) of the paper from below has a high surface tension and spreads easily on the upper surface because there is relatively little chemical solution on the upper surface.

In addition, the "chemical solution content" is measured at 23°C, 50% RH under the standard conditions of JIS P8111. 10.0 to 35.0% by weight in each sheet humidified with H.
When measuring the chemical content, each sheet of the chemical-coated multilayer sanitary thin paper was peeled off, the weight (a) was measured under the standard conditions of JIS P 8111, and the ratio of ethyl alcohol: acetone was set to 50:50 with a Soxhlet extractor. A test piece is placed in a solvent and kept in a lightly boiling state for about 3 hours to elute the chemical applied to the chemical-coated multilayer sanitary thin paper. A test piece is taken out, dried at 60° C. to a comparable weight, and the weight (b) is measured.

90... Means for applying chemical solution, 100... Rotor dampening spray device, 1R to 4R... Ply, F... Coating surface, S1 to S4... Sheet (ply), W... Non-coating surface.

Claims (4)

In manufacturing a tissue paper consisting of a laminated sheet in which 3 plies or 4 plies are laminated,
Each ply contains a water-based humectant that exhibits hygroscopicity,
Each ply has a difference in arithmetic mean height Sa according to ISO 25718 between its two sides,
applying the moisturizer to each of the plies;
Here, applying the moisturizing agent to the outer surface of each ply positioned outside the laminated sheet in a state where the arithmetic mean height Sa is small,
folding the laminated sheet to which the moisturizing agent has been applied to each of the plies;
A method for producing tissue paper, comprising: 2. The method for producing tissue paper according to claim 1, wherein the content of said moisturizing agent in each ply is 10.0 to 35.0% by mass . 2. The method for producing tissue paper according to claim 1, wherein the coating is performed by a flexographic transfer printing method. A method for producing a tissue paper product in which tissue paper made of a laminated sheet in which 3 or 4 plies are laminated is stored in a storage body,
Each ply contains a water-based humectant that exhibits hygroscopicity,
Each ply has a difference in arithmetic mean height Sa according to ISO 25718 between its two sides,
applying the moisturizing agent to each ply by a flexographic transfer printing method;
Applying the moisturizing agent to the outer surface of each ply located outside the laminated sheet while the outer surface of each ply has the smaller arithmetic mean height Sa;
folding the laminated sheet to which the moisturizing agent has been applied to each of the plies;
After that, it is stored in the storage body in a folded state;
A method for producing tissue paper, comprising:

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