JP6721437B2 - Toilet roll - Google Patents

Description

The present invention relates to a two-ply toilet roll.

In order to secure the texture of the toilet paper, the ease of wiping, the water absorption, etc., the toilet paper is laminated in two plies and subjected to so-called double embossing (Patent Documents 1 to 3).
In the double embossing, each sheet of 2-ply toilet paper is embossed and laminated in two plies so that the convex surfaces of the embossing of each sheet face each other.

Japanese Patent No. 3619808 Japanese Patent No. 4180263 Japanese Patent No. 5336744

By the way, in recent years, toilets with warm water flush toilet seats have become widespread, but since hot water flush toilet seats apply water locally, there is a problem that water easily adheres to the toilet paper during use, making it stronger. There is a need.
However, when the embossing process is performed by increasing the strength of the base paper, the smoothness becomes poor. On the other hand, when the embossing treatment is performed with the strength of the base paper reduced, the softness can be secured, but the strength decreases. Therefore, it has been difficult to achieve both strength, softness, smoothness, and water absorption.
Therefore, it is an object of the present invention to provide a toilet roll having improved strength, softness, smoothness, water absorbency, and beauty.

The present inventors examined the smoothness of the toilet paper, and when the surface of the toilet paper was smooth without embossing, the surface was too smooth and the surface felt crisp, and the toilet paper might feel stiff, which is uneven. It was found that the smoothness and the cosmetic appearance can be improved moderately by appropriately adding embossing. Specifically, by providing the first embossing and the second embossing smaller than this on the outer surface of the roll where water easily adheres to the toilet paper when using the toilet bowl with warm water washing, even if the strength is increased, it is soft and smooth. It has been found that the water absorbency and cosmetic properties are improved.
Of these, if there are few areas where the relatively large first embosses are densely packed, the specific volume and aesthetic properties will be low, and if this area is too large, the specific volume will be high, but rather the smoothness will be reduced. On the other hand, if there are few areas where the second embosses are densely arranged, the smoothness is lowered, and if there are too many areas, the smoothness is improved but the specific volume is lowered. Here, when the specific volume is increased, the softness and the water absorption are improved, but the smoothness tends to decrease. When the specific volume is low, smoothness is improved, but softness and water absorption tend to be decreased.

In order to solve the above-mentioned problems, the toilet roll of the present invention is a toilet roll in which two or more plies of toilet paper are wound up in a roll shape, which is double-embossed and has a strength DGMT of 2 When the outer surface of the toilet paper roll is the roll surface and the inner surface of the roll is the back surface of the roll, the roll surface is 0.6 to 4.5 N/25 mm, the specific volume is 7.0 to 10.5 cm ³ /g. A plurality of first embossing having an area of 2.5 to 7.0 mm ^{2 and} a plurality of second embossing having an area smaller than the first embossing, and at least a plurality of the second embossing being arranged on the back surface of the roll, When the area of 10 cm×10 cm excluding the perforations on the roll surface is divided into 100 square cells of 1 cm×1 cm, 30 to 70 of the squares including 7 or more of the first emboss In the area, the first embossing does not exist, and the second embossing has 6 to 30 circles with a diameter of 14 mm therein, and the tissue softness measuring device TSA is used to measure the roll surface. The toilet paper on the side, with respect to the sample installed on the sample table with the roll surface facing up, the bladed rotor is rotated at a rotation speed of 2.0 (/sec) after being pressed from above as a pressing pressure of 100 mN, and the sample table When the vibration of the roll is measured by the vibration sensor, the smoothness (TS750f) of the roll surface, which is automatically obtained by the software on the TSA and is represented by the intensity of the maximum peak of the first spectrum from the low frequency side, is 11 ~35, the smoothness (TS750b) of the roll back surface measured by the tissue softness measuring device TSA with respect to the sample in which the toilet paper on the roll back surface side is placed on the sample table with the roll back surface facing up 20 to 48.

It is preferable that the area of the second emboss is less than 2.2 mm ² .
The ratio represented by (number of circles (number))/(number of second embosses on the back surface of the roll (number/cm ² )) is preferably 0.05 or more.
The number of the second embosses on the back surface of the roll is preferably 30 to 75 pieces/cm ² .
When water is dripped on the roll surface side of the toilet paper, the water absorption degree (dripping amount is 0.1 ml) based on old JIS standard S3104 is preferably 0.0 to 2.0 seconds.
Of the toilet paper, the average value of the looseness according to JIS P4501 is 15.0 to 90.0 seconds for the 1-ply sheet on the roll front side and the 1-ply sheet on the back side of the roll. Is preferred.
The toilet paper preferably has a basis weight of 25 to 45 g/m ² and a paper thickness of 0.22 to 0.40 mm.

According to this invention, the strength is increased by providing the first emboss and the second emboss having a predetermined area and distribution on the outer surface of the roll where water easily adheres to the toilet paper when using the warm water washing toilet seat. In addition, it is possible to obtain a toilet roll having improved softness, smoothness, water absorbency, and beauty.

It is a perspective view showing appearance of a toilet roll concerning an embodiment of the present invention. It is a top view which shows the embossing provided in the roll surface. It is a top view which shows the embossing provided in the roll back surface. It is sectional drawing which follows the AA line of FIG. It is a figure which shows the measurement principle of the tissue softness measuring device TSA. It is a figure which shows an example of the analysis result of the vibration frequency of the paper sample sample by TSA. It is a figure which shows an example of an embossing apparatus. It is a figure which shows another example of an embossing apparatus. It is a figure which shows the measuring method of the area of embossing. It is another figure which shows the measuring method of the area of embossing. It is a figure which shows the measuring method of the number of cells which contain 7 or more 1st embossing. It is a figure which shows the measuring method of the number of 14 mm diameter circles in which the 1st embossing does not exist and the 2nd embossing exists inside. It is a figure which shows the specific measuring method of the area and depth of embossing. It is a figure following FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described, but these are provided for the purpose of illustration and do not limit the present invention.
As shown in FIG. 1, a toilet roll 10 according to an embodiment of the present invention is a toilet roll in which two or more plies of toilet paper 10x are wound into a roll, and is double-embossed and has a strength DGMT. Is 2.6 to 4.5 N/25 mm, the specific volume is 7.0 to 10.5 cm ³ /g, the first embossing 2 and the second embossing 4 described later are arranged, and (TS750f) described later is 11 to 35. , (TS750b) is 20 to 48.
The surface of the toilet paper 10x outside the roll is referred to as a roll surface 10a, and the inside surface of the roll is referred to as a roll back surface 10b.

When the longitudinal tensile strength of the toilet paper 10x during drying based on JIS P8113 is DMDT (Dry Machine Direction Tensile strength) and the lateral tensile strength during drying is DCDT (Dry Cross Direction Tensile strength), the strength is DGMT (Dry Geometric Mean Tensile strength) is represented by (DMDT×DCDT) ^1/2 . In addition, DMDT and DCDT are measured with respect to the product of the toilet paper 10x that is still stacked in two or more plies.
If the DGMT is less than 2.6 N/25 mm, it easily shakes and is not suitable for practical use, and if it exceeds 4.5 N/25 mm, it becomes hard and the softness is impaired. The DGMT is preferably 2.8 to 4.0 N/25 mm, more preferably 3.0 to 3.6 N/25 mm.
Also, DMDT is preferably 5.5 to 9.5 N/25 mm, more preferably 6.0 to 8.6 N/25 mm, most preferably 6.5 to 7.5 N/25 mm, and DCDT is preferably 1.2 to. It is 2.1 N/25 mm, more preferably 1.3 to 1.9 N/25 mm, and most preferably 1.4 to 1.7 N/25 mm.
If DMDT and DCDT are less than the above values, they may be easily shaken and not suitable for practical use. When DMDT and DCDT are higher than the above-mentioned values, it becomes hard and softness may be impaired. The tensile speed during DMDT and DCDT measurement is 300 mm/min.
The flow direction of sanitary thin paper is defined as "longitudinal direction" and the direction perpendicular to the flow direction is defined as "transverse direction".

When the specific volume of the toilet paper 10x is less than 7.0 cm ³ /g, the softness is poor, the paper is too smooth, and the water absorption is poor. On the other hand, when the specific volume exceeds 10.5 cm ³ /g, the bulk (bulkness) increases and the softness improves, but the smoothness deteriorates. The specific volume is preferably 7.7 to 10.0 cm ³ /g, more preferably 8.5 to 9.5 cm ³ /g.
The specific volume is expressed by the volume cm3 per unit g, which is obtained by dividing the paper thickness to be measured, respectively, as described later.

2 and 3 show the embossing provided on the roll front surface 10a and the roll back surface 10b, respectively. 4 is a sectional view taken along the line AA of FIG.
As shown in FIG. 2, a plurality of first embossings 2 having an area of 2.5 to 7.0 mm ^{2 and} a plurality of areas smaller than the first embossing 2 (preferably 2.2 mm ² or less) are provided on the roll surface 10 a. The second embossing 4 is arranged. Here, the first embossing 2 is a large and deep macro embossing and has a function of ensuring a specific volume and aesthetics. On the other hand, the second embossing 4 is a small and shallow micro embossing and has a function of ensuring appropriate smoothness.
When the area of each first embossing 2 on the roll surface 10a is less than 2.5 mm ² , the specific volume is less than 7.0 cm ³ /g, and the cosmetic appearance is poor. When the area exceeds 7.0 mm ² , the specific volume exceeds 10.5 cm ³ /g, the smoothness is poor, and the first embossing is too large, resulting in poor strength. The area of each first embossing 2 is preferably 3.3 to 6.2 mm ² , more preferably 4.0 to 5.5 mm ² .
The depth of the first embossing 2 on the roll surface 10a is preferably 0.25 to 0.70 mm, more preferably 0.25 to 0.60 mm, and most preferably 0.25 to 0.50 mm. If the depth of the first embossing 2 is smaller than the above range, the specific volume may be small, and if the depth exceeds the above range, the specific volume may be too large and the smoothness may be poor.

The area of each second embossing 4 on the roll surface 10a is preferably 2.2 mm ² or less. If the above area exceeds 2.2 mm ² , smoothness may be poor. The lower limit of the area of the second embossing 4 is not particularly limited, but is, for example, 0.5 mm ² . If the area of the second embossing 4 is less than the lower limit, it may be difficult to manufacture and may become too smooth. The area of each second embossing 2 on the roll surface 10a is preferably 1.0 to 2.2 mm ² , more preferably 1.4 to 2.2 mm ² .
The depth of the second embossing 4 on the roll surface 10a is preferably 0.05 to 0.23 mm, more preferably 0.10 to 0.23 mm, and most preferably 0.10 to 0.20 mm. If the depth of the second embossing 4 is smaller than the above range, it may be too smooth, and if it exceeds the above range, the smoothness may be poor.
The first emboss 2 and the second emboss 4 on the roll surface 10a may overlap (that is, the second emboss 4 is formed on the first emboss 2), but it is preferable that they do not overlap.

The area of the emboss is obtained by measuring the height difference of the emboss using a shape measuring laser microscope. The shape measuring laser microscope scans a laser light source, which is a point light source, through an objective lens into pixels obtained by dividing an XY plane in an observation visual field into a plurality of pixels, and detects reflected light of each pixel by a light receiving element. .. Then, the objective lens is driven in the height (Z-axis) direction, and the height information and the reflected light amount are detected with the Z-axis position having the highest reflected light amount as the focal point. By repeating the scan in this way, a light intensity super-depth image and a high-low image (information) that are entirely focused can be obtained. Since the laser light source is a pinhole confocal optical system, the measurement accuracy is high.
As the shape measuring laser microscope, a product name “One-shot 3D measuring macroscope VR-3100” manufactured by KEYENCE can be used. The product name "VR-H1A" can be used as the software for observing, measuring, and analyzing images of the laser microscope. Further, the measurement conditions are such that the magnification is 12 times and the visual field area is 24 mm×18 mm. The measurement magnification and the field of view may be appropriately changed depending on the size of the emboss to be obtained.

As shown in FIG. 9, the area of the emboss is measured by measuring the length a of the longest part of the peripheral edge fr of the emboss and the length b of the longest part in the direction perpendicular to the length a, and measuring the area a×b. Calculate as S.
Further, as shown in FIG. 10, when the first embossing 2 and the second embossing 4 overlap each other, including the overlapping portion, the length a of the longest part of the peripheral edge of the first embossing 2 and the length The length b of the longest part in the direction perpendicular to a is measured. Further, the area S2 of the single second emboss 4 which does not overlap the first emboss 2 is obtained in the same manner as in FIG. Then, (a×b)−{1/2×S2×(number of overlaps)} is obtained as the area S of the first embossing 2. In FIG. 10, the number of overlaps of the first emboss 2 and the second emboss 4 is 2, and the area S=(axb)-S2.

13 and 14 show a specific method for measuring the area (length a, b) and depth of embossing. FIG. 13A shows a height profile on the XY plane by the shape measuring laser microscope, and it can be seen that the height of the toilet paper surface is represented by shading. The dark portion in FIG. 13( a) indicates each first emboss 2, and when a line segment AB crossing the longest part of one of the first emboss 2 is drawn, as shown in FIG. 13( b ). A height (measurement sectional curve) profile of the first embossing 2 is obtained. Here, since the convex portion and the concave portion of the emboss can be recognized by the shade of the color of the XY plane image, the line segment AB can be determined so as to cross the portion where the convex portion and the concave portion are adjacent to each other. Of course, when the longest part of the first embossing 2 is in the vertical direction, the line segment AB can be in the vertical direction.

Here, the height profile in FIG. 13B is a (measurement) cross-section curve S representing the unevenness of the sample surface of the actual toilet paper, but noise (there is a fiber lump on the surface of the toilet paper, fibers are It also includes a sharp peak due to a beard-like extension or a portion without fibers), and it is necessary to remove such a noise peak when calculating the height difference of the unevenness.
Therefore, as shown in FIG. 14, a “contour curve” W is calculated from the sectional curve S of the height profile, and two inflection points P1 and P2 that are convex upward in the contour curve W and the inflection The minimum value sandwiched between the points P1 and P2 is obtained and is set as the minimum depth value Min. Further, the average value of the depth values of the inflection points P1 and P2 is set as the maximum depth value Max.
In this way, the depth of embossing=maximum value Max−minimum value Min. Further, the distance (length) on the XY plane between the inflection points P1 and P2 is defined as the length a. In addition, the "contour curve" is a wavelength shorter than λc: 250 μm (where λc is the "filter that defines the boundary between the roughness component and the waviness component" described in JIS-B0601 "3.1.1.2") from the sectional curve. It is a curve obtained by removing a component of surface roughness by a low pass filter. The same applies to the length b. Also, from the height profile when the length b is obtained, find the embossing depth in the same manner as above, compare it with the embossing depth when finding the length a, and select the larger value for the embossing depth. To be adopted as.

In the present invention, as shown in FIG. 11, a region R of 10 cm×10 cm excluding perforations in the roll surface of the toilet paper 10x has 100 square cells SQ1, SQ2... 1 cm×1 cm. When divided into sections, there are 30 to 70 cells SQ1 containing 7 or more first embosses 2 (cells shaded in gray in FIG. 11). In the example of FIG. 11, the number of cells SQ1 is 50.
The mesh SQ1 represents a region where the first embossing 2 is dense (7 or more/cm2) and affects the specific volume, so it is necessary to appropriately control the number of the mesh SQ1. When the number of cells SQ1 is less than 30, the specific volume may be low and the surface may be too smooth, and the softness may be poor. Also, the cosmetic properties are poor. When the number of cells SQ1 exceeds 70, the specific volume increases, but the smoothness deteriorates.
The number of cells SQ1 is preferably 35 to 65, and more preferably 45 to 60. When the area R of 10 cm×10 cm cannot be secured due to knurling (edge embossing) treatment, for example, for each of two continuous sheets adjacent to each other in the length direction through the perforations, 5 cm× The measurement is performed on a region of 10 cm, and the numbers of these two regions are added together to be converted into a region R of 10 cm×10 cm.

Further, in the present invention, as shown in FIG. 12, 6 to 30 circles CR having a diameter of 14 mm in which the first emboss 2 does not exist and the second emboss 4 exists inside the region R described above. is there.
The circle CR represents a region touched by the tip of a finger, and the number of circles CR affects the smoothness, so it is necessary to appropriately control the number of circles CR. If the number of circles CR is less than 6, the smoothness will be poor, and if it exceeds 30, the smoothness will be improved, but the specific volume will be low.
The circle CR is preferably 8 to 25, and more preferably 10 to 20.

On the other hand, as shown in FIG. 3, a plurality of second embosses 4 are arranged on the roll back surface 10b. The area and depth range of the second embossing 4 on the roll back surface 10b are the same as the area and depth range (described above) of the second embossing 4 on the roll front surface 10a.
Further, the number Y of the second embossing fourth roll back surface 10b is preferably 30 to 75 pieces / cm ^2, more preferably 40 to 75 pieces / cm ^2, most preferably 50-75 pieces / cm ^2. If the number Y of the second embosses 4 is less than the above range, there may be almost no embossing, and the roll back surface 10b may be too smooth and too smooth. If it exceeds the above range, the smoothness may be poor. Further, when the number Y of the second embosses 4 on the roll back surface 10b is out of the above range, the difference in smoothness between the roll front surface and the roll front surface (the difference between the front surface and the back surface) becomes large, which may cause a feeling of discomfort.
The number Y of the second embosses 4 is measured with respect to the entire width of the toilet paper and the entire area between two perforations adjacent to each other in the length direction. Incidentally, like knurling (edge embossing) process is performed, if not be measured at full width, the embossed number measured for knurling (Edge embossing) can be measured except for portions that can not be measured in the process such as site, 1 cm ² per Converted as the number of embossed.

Further, the roll back surface 10b may be provided with an emboss other than the second emboss 4 (for example, the first emboss 2), but in order to ensure smoothness, (number of circles CR (piece))/(roll) The ratio represented by the number Y (number/cm ² ) of the second embosses 4 on the back surface 10b is preferably 0.05 or more. By doing so, the difference in smoothness between the front and back surfaces of the roll back surface 10b and the roll front surface 10a becomes small, and the tactile feel becomes good. However, if the above ratio is less than 0.05, the smoothness of the roll surface 10a may be poor, and the difference in tactile feel between the front and back sides (difference in smoothness between the front and back sides) may become too large.
The above ratio is more preferably 0.15 or more, and most preferably 0.20 or more.
It is preferable that no embossing other than the second embossing 4 is provided on the roll back surface 10b.

Then, as shown in FIG. 4, the two plies are laminated so that the convex surfaces of the first emboss 2 and the second emboss 4 respectively processed on the two-ply toilet paper face each other.

The tissue softness measuring device TSA (Tissue Softness Analyzer) is used to install the toilet paper 10x with two or more plies stacked on the sample table with the roll surface side (sheet) facing up When the sample table vibration is measured with a vibration sensor after rotating the sample table from above with a pushing pressure of 100 mN and rotating it at a rotation speed of 2.0 (/sec), from the low frequency side automatically acquired by the software on the TSA. The value of the intensity (TS750) of the maximum peak of the first spectrum (denoted as "TS750f") is preferably 11 to 35 dBV ² rms, more preferably 15 to 31 dBV ² rms, most preferably 19 to 27 dBV ² rms. Is.
Regarding the toilet paper 10x that is still stacked on two or more plies, the value of the above TS750 (this is referred to as "TS750b") is obtained for the sample installed on the sample table with the (the sheet of) the back side of the roll facing up. It is preferably 20 to 48 dBV ² rms, more preferably 25 to 43 dBV ² rms, most preferably 30 to 38 dBV ² rms.
When the value of TS750f (TS750b) is higher than the above range, the smoothness is inferior, and when it is lower than the above range, the surface is too smooth and the surface feels crispy, and the first embossing 2 is small and the depth is shallow, resulting in a beauty ( Appearance and appearance may be inferior. Here, if the first embossing 2 is too small or its depth is too shallow, the appearance of the first embossing 2 will be blurred and it will be difficult to recognize it, and the cosmeticity of the embossing will deteriorate.

Here, as shown in FIG. 5, the tissue softness measuring device TSA210 performs vibration analysis on vibration data detected by various sensors when the rotor with blades 204 rotated is pressed from above the paper sample (sample) 206. The softness (feeling) of the paper is quantitatively evaluated by parameterizing (TS value), and the product name is manufactured by Germany's Emtec Electronic GmbH (Japanese agent is Nippon Luft Co., Ltd.). Is.
A specific measurement using TSA is as follows: (i) A sample 206 (a sample processed into a circular shape having a diameter of about 112.8 mm using a sample punch manufactured by emtec) is installed so as to cover the circular sample base 205 from the outside. , The outer periphery of the sample 206 is held by the sample fixing ring 208, (ii) after the rotor with blades 204 is pushed from above the sample 206 with a pushing pressure of 100 mN, the rotor 204 is rotated at a rotation speed of 2.0 (/sec), (iii) The vibration of the sample table 205 is measured by the vibration sensor 203 installed inside the sample table 205, and the vibration frequency is analyzed. (iv) Next, at the pushing pressures of 100 mN and 600 mN, the deformation displacement amounts (mm/N, rigidity D) in the vertical direction when the sample 206 is deformed without rotating the rotor 204 are measured. By the steps (i) to (iv), the elements (smoothness, suppleness, volume) of the overall handfeel value of the product can be digitized. The measurement is performed 5 times for one sample and averaged.

The sample table 205 is installed on the base plate 201, and the force sensor 202 is arranged between the sample table 205 and the base plate 201. Then, the pressing value of the rotor with blades 204 is controlled by the detection value of the force sensor 202. Further, the bladed rotor 204 is rotated by the motor 209.
In addition, emtec measurement system is used as software for performing vibration analysis and parameterization (TS value). This software is equipped with various algorithms (for example, Base Tissue, Facial, TP, etc.) and automatically acquires TS7, TS750, D (rigidity) on the software, and these TS7, TS750, D and basis weight , HF (hand feel) value is calculated from the thickness, the Ply number, and the like according to various kinds of algorithms. In the present invention, only the TS750 is specified, not the HF value. Any algorithm may be used as long as the above measurement conditions are satisfied, and the value of TS750 does not change depending on the type of the algorithm.

FIG. 6 shows an example of the analysis result of the vibration frequency of the paper sample sample by TSA. The intensity of the maximum peak A of the first spectrum from the low frequency side is TS750, and the intensity of the maximum peak B of the spectrum including 6500 Hz (before and after 6500 Hz) is TS7. The maximum peak B is usually located at about 6500 Hz.
The lower the value of TS750, the better the smoothness. By defining TS750, it is possible to quantitatively evaluate the smoothness, which has conventionally been subject to the subjectivity of the evaluator.

When water is dripped on the roll surface side of the toilet paper 10x, the water absorption degree (dripping amount is 0.1 ml) based on old JIS S3104 is preferably 0.0 to 2.0 seconds, and 0.0 to 1.5 seconds. Is more preferable, and 0.0 to 1.0 second is the most preferable. The higher the water absorption, the better, but it is difficult to measure the water absorption of 1.0 seconds or less, so the water absorption of 1.0 seconds or less is regarded as "1.0 seconds". If the water absorption exceeds 2.0 seconds, the water absorption may be poor.
In addition, the water absorption is measured for the product of the toilet paper 10x that is still stacked in two or more plies.

For the 1-ply sheet on the roll surface side and the 1-ply sheet on the roll back surface side of the toilet paper 10x, the average value of the ease of loosening according to JIS P4501 is preferably 15.0 to 90.0 seconds, and 20 0.0 to 70.0 seconds is more preferable, and 25.0 to 50.0 seconds is most preferable. If the easiness of loosening is less than the above range, it tends to be broken, and if it exceeds the above range, water disintegration in a toilet may be poor.
For example, in the case of a 3-ply toilet paper 10x, the looseness of each sheet on the front and back sides of the roll is measured and the average value of the two is obtained, but the center sheet in the thickness direction sandwiched between the front and back sheets is do not use.

The toilet paper 10x preferably has a basis weight of 25 to 45 g/m ² and a paper thickness of 0.22 to 0.44 mm.
When the grammage is less than 25 g/m ² or the paper thickness is less than 0.22 mm, the strength may decrease and the volume feeling (bulkiness) may decrease. If the basis weight exceeds 45 g/m ² , the softness may be poor, and if the paper thickness exceeds 0.40 mm, the roll diameter may be too large.
The basis weight is more preferably 28 to 40 g/m ² , most preferably 30 to 34 g/m ^2, and the paper thickness is more preferably 0.24 to 0.36 mm, most preferably 0.27 to 0. It is 0.30 mm.

The toilet paper may consist of 100% by mass of wood pulp, and may include waste paper pulp and non-wood pulp. In order to obtain the target quality, it is preferable to use NBKP (softwood kraft pulp):LBKP (hardwood kraft pulp)=50 to 90:10 to 50 (mass ratio) as a raw material, and a more preferable range is NBKP:LBKP=60-80:20-40:50, and a more preferable range is NBKP:LBKP=65-75:25-35.
Pulp manufactured from Eucalyptus genus Eucalyptus represented by Eucalyptus grandis and Eucalyptus globulus is preferable as the LBKP material. Further, up to 100 parts by mass of waste paper pulp derived from a milk carton may be contained with respect to 100 parts by mass of the NBKP and LBKP pulps. Since waste paper pulp has a large quality variation, and if the blending ratio increases, it has a great influence on the quality of the product, especially the softness, so that it is preferably 50 parts by mass or less, and more preferably 100 parts by mass of pulp of NBKP and LBKP. It is desirable to add 20 parts by mass or less, more preferably 5 parts by mass or less, and most preferably 0 parts by mass.
In order to ensure proper strength in the toilet paper, it is possible to mix the raw materials by an ordinary means and adjust the strength by beating the pulp fiber. As the beating to obtain the target quality, a commercially available virgin pulp has a Canadian standard freeness measured by JIS-P8121 of 50 to 350 ml, more preferably 70 to 300 ml, and further preferably 100 to 250 ml. Reduce water level. It is also preferable not to use a wet strength agent.

In the case of using a virgin raw material for the stock, the toilet paper can be prepared by blending a softwood kraft pulp and a hardwood kraft pulp having a fiber length and a fiber roughness within a certain range in a specific range. As an additive to paper materials, depending on the quality required for the final product, softeners including debonder softeners, bulking agents, dyes, dispersants, dry paper strength enhancers, drainage improvers, pitch control agents, absorbency Improvers, wetting agents and the like can be used.
When using a waste paper material as toilet paper, the same treatment as in the case of the virgin type is performed.

The toilet paper of the present invention can be manufactured, for example, as follows.

(1) Papermaking First, a web is made from the above-mentioned stock on a wire part of a known paper machine, and is pressed by a Yankee dryer with one or two roll press nips through a felt to be dehydrated, and then a Yankee dryer (cylinder). Apply and dry, then crepe when peeling the web from the Yankee dryer. Examples of the wire part method include a round net type, a long net (Ford linear) type, a suction breast type, a short net type, a twin wire type, and a crescent former.
Here, there is a technique in which a roll press is placed in a loop of a fabric having unevenness instead of felt, and the unevenness of the fabric is added to the wet paper to make it bulky to increase the specific volume. However, in this case, since the unevenness derived from the unevenness of the fabric is attached to the toilet paper base paper and it becomes difficult to give the minute second embossing 4, it is possible to perform the roll press using the felt without using the fabric. It is preferable. As the textured fabric, the top surface (the surface where the wet paper and the wire come into contact) has a warp and weft count of 20 to 70/2.54 cm, and the warp and weft wire diameters are 0.21 to 0.70 mm. One made of a mesh-like wire in which the warp and the weft are woven. Therefore, the number of warp threads and weft threads on the top surface (the surface where the wet paper and the wire come into contact) is 70 or more/2.54 cm, and the warp and weft have a wire diameter of 0.21 mm or less. If it is a fabric made of the above wire, it has fine meshes and few irregularities, so it may be used for roll pressing. The wire diameter on the top surface is a weighted average value of the number of wires and the wire diameter.

(2) Embossing Process FIGS. 7 and 8 each show an example of an embossing device that performs an embossing process.
In the embossing device of FIG. 7, the convex embossing roll 20 made of metal and the rubber pressing roll facing each other are separately formed so that the convex surface 20x of the first embossing 2 and the convex surface 40x of the second embossing 4 do not overlap each other. The first embossing 2 and the second embossing 4 are applied at the same time by passing a one-ply toilet paper on the roll surface 10a side between and.
On the other hand, the one-ply toilet paper on the roll back surface 10b side is passed between the metal convex embossing roll 40 on which the convex surface 40x of the second embossing 4 is formed and the opposing rubber restraining roll, and the second embossing 4 Is given. Then, after appropriately applying an adhesive (ply bond) to the embossed convex surfaces of both toilet papers, the two embossed convex surfaces of each toilet paper are laminated and adhered to each other with a stacking roll. , Toilet roll is manufactured by winding appropriately.
Here, since the convex embossing roll 20 has the convex surface 20x and the convex surface 40x at different positions, the first embossing 2 and the second embossing 4 can be applied at the same time, and the first embossing 2 and the second embossing 4 on the roll surface 10a can be provided. You can avoid overlapping.
Note that, instead of ply bonding, two plies may be laminated by knurling (edge embossing), but ply bonding is preferable.

On the other hand, in the embossing apparatus of FIG. 8, between the convex embossing roll 40 on which the convex surface 40x of the second embossing 4 is formed and the opposing rubber pressing roll, the 1-ply toilet paper on the roll surface 10a side is placed. Then, the second embossing 4 is applied. Then, 1-ply toilet paper on the roll surface 10a side is passed between the metal convex embossing roll 30 on which the convex surface 20x of the first embossing 2 is formed and the opposing rubber restraining roll, and the first embossing 2 Is given. Therefore, the first emboss 2 and the second emboss 4 on the roll surface 10a may overlap each other.

It is needless to say that the present invention is not limited to the above-described embodiments and covers various modifications and equivalents included in the concept and scope of the present invention.

The pulp composition (% by mass) was NBKP 70% and LBKP 30%, and roll press was performed through a felt by a known method to produce paper. Then, it embossed with the embossing apparatus shown in FIG. 7, and manufactured the toilet roll.

The following evaluation was performed.
The maximum load until breakage was measured in units of N/25 mm for the toilet paper 10x based on the tensile strength in dry direction DMDT and the tensile strength in dry direction DCDT: JIS P8113.
Basis weight: The toilet paper 10x was measured based on JIS P8124.
Paper thickness: The toilet paper 10x was measured using a thickness gauge (a dial thickness gauge "PEACOCK" manufactured by Ozaki Seisakusho). The measurement conditions were a measurement load of 3.7 kPa, a probe diameter of 30 mm, a sample was placed between the probe and the measuring table, and the gauge was read when the probe was lowered at a speed of 1 mm or less per second. The measurement was performed by stacking 10 sheets of toilet paper 10x. The measurement was repeated 10 times and the measurement results were averaged. Then, the obtained average value per one operation was divided by the number of sheets to obtain the paper thickness per 10x of toilet paper.
Specific volume: The thickness of the toilet paper 10x was divided by the grammage and expressed in volume cm ³ per unit g.
Water absorption: According to the old JIS-S3104 method, 0.1 ml of purified water is dripped on the roll surface side of the toilet paper 10x at a temperature of 23±1° C. and a humidity of 50±2%. ) Was measured.
Ease of loosening: The ease of loosening was measured as described above according to JIS P4501.

The measurement of TS750 was performed using the above-mentioned tissue softness measuring device TSA. The measurement conditions are also as described above.
Sensory evaluation was performed by 20 monitors. The evaluation standard was 5 points. It is good if the evaluation standard is 3 points or more.
The "softness" was evaluated by touching both the front surface and the back surface of the two-ply toilet paper 10x.
“Front-back difference” was evaluated by touching both the front and back surfaces of the two-ply toilet paper 10x and feeling whether the tactile sensations were the same. The tactile difference between the front and back indicates the difference between the front and back when the second emboss is applied. The higher the evaluation, the more the same tactile sensation is felt, and the lower the evaluation, the larger the tactile difference.
The cosmetic properties were evaluated by visually observing the appearance and appearance of the first embossing 2 on the surface of the toilet paper 10x. If the first embossing 2 is too small or the depth thereof is too shallow, the appearance of the first embossing 2 is blurred and it is difficult to recognize the appearance, so that the cosmetic quality is deteriorated.
As for "balance of smoothness (surface)", TS750f has a score of less than 10.0 at 1 point, 10.0 to 10.9 at 2 points, 11.0 to 14.9 at 3 points, and 15.0 to 18.9. 4 points, 19.0 to 27.0 5 points, 27.1 to 31.0 4 points, 31.1 to 35.0 3 points, 35.1 to 37.0 2 points, 38. 1 or more was 1 point.
"Smoothness balance (back side)" is 1 point for TS750b less than 19.0, 2 points for 19.0-19.9, 3 points for 20.0-24.9, and 25.0-29.9. 4 points, 30.0 to 38.0 5 points, 38.1 to 43.0 4 points, 43.1 to 48.0 3 points, 48.1 to 50.0 2 points, 50. 1 or more was 1 point. In other words, the "smoothness balance" is evaluated low whether it is higher or lower than the reference TS750.
As for water absorption, when the water absorption value is 1.0 second or less, the evaluation is 5 points, 1.1 to 1.5 is 4 points, 1.6 to 2.0 seconds is 3 points, and 2.1 to 2.3 seconds. Was 2 points and 2.4 seconds or more was 1 point.
In addition, the basis weight, tensile strength, thickness, specific volume, and measurement by the tissue softness measuring device TSA are equilibrium under the temperature and humidity conditions (23±1° C., 50±2% RH) specified in JIS-P8111. It was carried out after holding the state.

The obtained results are shown in Tables 1 to 4. In each table, a design in which the first embossing and the second embossing on the roll surface are the same as in FIG. 2 is described as “FIG. 2”, and a design different from FIG. 2 is described as “change”.

As is clear from Tables 1 to 4, in the case of each example in which the first embossing and the second embossing having a predetermined area and distribution are provided on the roll surface, and DGMT, specific volume, and smoothness TS750 are specified, the strength is The softness, smoothness and water absorption were improved even when the value was raised.

On the other hand, in Comparative Examples 1 and 10 in which the strength DGMT was less than 2.6 N/25 mm, the strength was poor. In the case of Comparative Example 1, since the basis weight was less than 25 g/m ² and the paper thickness was less than 0.22 mm, the water absorption and the volume feeling (bulkness) were also reduced. Further, in the case of Comparative Example 10, the number of the second embossments on the back surface of the roll exceeded 75 pieces/cm ² , the smoothness was poor, and the difference between the front and back surfaces was aggravated.
In Comparative Examples 2 and 9 in which the strength DGMT was more than 4.5 N/25 mm, the softness was poor. Further, in the case of Comparative Example 9, the number of second embossments on the back surface of the roll was less than 30 pieces/cm ² , so there was almost no embossing, and the surface was too smooth, too smooth, and the difference between the front and back surfaces deteriorated.

In the case of Comparative Example 3 in which the number of meshes containing 7 or more first embosses on the roll surface is less than 30, the specific volume is less than 7.0 cm ³ /g, and the softness, cosmetic properties and water absorption are poor, and the surface is too smooth. , The difference between front and back has also worsened.
In the case of Comparative Example 4 in which the number of meshes containing seven or more first embosses on the roll surface exceeded 70, the specific volume exceeded 10.5 cm ³ /g, the bulk (bulk height) increased, and the softness improved. However, it was not smooth.

In the case of Comparative Example 5 in which the area of the first embossing on the roll surface is less than 2.5 mm ² , the specific volume is less than 7.0 cm ³ /g, and the softness, beauty and water absorption are the same as in Comparative Example 3. inferior. In the case of Comparative Example 5, the area of the first emboss=the area of the second emboss.
In the case of Comparative Example 6 in which the area of the first embossing on the roll surface exceeded 7.0 mm ² , the specific volume exceeded 10.5 cm ³ /g and the surface was inferior in smoothness as in Comparative Example 4, and the strength was also increased. inferior.

In the case of Comparative Example 7 in which the number of circles of 14 mm in diameter having the second embossment on the roll surface inside was more than 30, the specific volume was less than 7.0 cm ³ /g, and the softness and water absorption were the same as in Comparative Example 3. Inferiority, too smooth, and the difference between the front and back has worsened.
In the case of Comparative Example 8 in which the number of circles having a diameter of 14 mm in which the second embossment on the roll surface was present was less than 6, the smoothness was poor and the difference in the tactile sensations between the front and back surfaces was large.

In the case of Comparative Example 11 in which the area of the second emboss on the roll surface was less than 0.5 mm ² , and in the case of Comparative Example 13 in which the second emboss was not provided on the roll surface, the surface was too smooth and the difference between the front and back surfaces was deteriorated. In Comparative Example 11, the area where the second embossing area is made as small as possible represents that the second embossing does not exist, so Comparative Example 11 also shows a state close to Comparative Example 13 in which the second embossing does not exist on the roll surface. It represents.
In the case of Comparative Example 12 in which the area of the second emboss on the roll surface exceeded 2.2 mm ² , the smoothness was poor.

No embossing was provided on either the roll front surface or the roll back surface, and instead, creping (creasing) was excessively performed after paper making, so that the specific volume was 7.0 to 10.5 cm as in the above-mentioned examples. ^In the case of Comparative Example 14 adjusted to within the range of ³ /g, both the roll front surface and the roll back surface were too smooth, and the strength was lowered and the roll was easily broken. Furthermore, the cosmetics were inferior because there was no embossing.
In Comparative Example 14 in which no emboss is provided, it is difficult to set the specific volume to 7.0 to cm ³ /g or more when the crepe attachment is set to the normal level.

The commercially available products 1 and 2 had a strength DGMT of less than 2.6 N/25 mm and were inferior in strength. Further, since the commercially available product 2 has a paper thickness of less than 0.22 mm, the volume feeling (bulkness) is also reduced.
The TS750b of the commercial product 3 was too high, and the smoothness of the back surface of the roll was poor. It is considered that the commercial product 3 had steep and sharp embossing, which caused a catch and was inferior in smoothness.

10 Toilet roll 10a Roll surface 10b Roll back surface 202 Force sensor 204 Rotor with blade 205 Sample stage 206 Sample 210 Tissue softness measuring device TSA
R Roll surface area of 10 cm×10 cm excluding perforations SQ1, SQ2 1 cm×1 cm square grid SQ1 Grid containing 7 or more first embosses CR The first emboss does not exist, and the second emboss Circle with a diameter of 14 mm inside

Claims (7)

It is a toilet roll made by rolling up two or more plies of toilet paper in a roll shape, which is double embossed,
The strength DGMT of the toilet paper is 2.6 to 4.5 N/25 mm, the specific volume is 7.0 to 10.5 cm ³ /g,
When the roll outer surface of the toilet paper is the roll surface and the roll inner surface is the roll back surface, a plurality of first embossings having an area of 2.5 to 7.0 mm ² are formed on the roll surface, and A plurality of small second area embossing is arranged, at least a plurality of the second embossing is arranged on the roll back surface,
When the area of 10 cm×10 cm excluding the perforations on the roll surface is divided into 100 square cells of 1 cm×1 cm, 30 to 70 of the squares including 7 or more of the first emboss And
Of the area, the first embossing does not exist, and the second embossing is 6 to 30 circles having a diameter of 14 mm.
And, with a tissue softness measuring device TSA, the number of revolutions after pushing the rotor with blade as a pushing pressure of 100 mN from above against the sample in which the toilet paper on the roll surface side is placed on the sample table with the roll surface facing up When rotating at 2.0 (/sec) and measuring the vibration of the sample table with a vibration sensor,
The smoothness (TS750f) of the roll surface represented by the intensity of the maximum peak of the first spectrum from the low frequency side, which is automatically acquired by the software on the TSA, is 11 to 35,
The smoothness (TS750b) of the roll back surface measured by the tissue softness measuring device TSA is 20 to 48 with respect to the sample in which the toilet paper on the roll back surface side is placed on the sample table with the roll back surface facing upward. There is a toilet roll. The toilet roll according to claim 1, wherein the area of the second emboss is less than 2.2 mm ² . The toilet roll according to claim 1 or 2, wherein a ratio represented by (the number of the circles (pieces))/(the number of the second embosses on the back surface of the roll (pieces/cm ² )) is 0.05 or more. Toilet rolls according to the claim 1 the number of the second embossing roll back surface is 30 to 75 pieces / cm ^2. When water is dripped on the roll surface side of the toilet paper, the water absorption degree (dripping amount is 0.1 ml) based on the old JIS standard S3104 is 0.0 to 2.0 seconds. The toilet roll according to item 1. The average value of the unraveling easiness according to JIS P4501 is 15.0 to 90.0 seconds for the 1-ply sheet on the roll front side and the 1-ply sheet on the back side of the roll of the toilet paper. Item 10. The toilet roll according to any one of items 1 to 5. The toilet basis weight 25 to 45 g / ^{m 2} paper, toilet rolls according to any one of claims 1 to 6 paper thickness is 0.22～0.40Mm.