JP2018138171A - Toilet roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toilet roll which has excellent softness of a sheet and a roll without decreasing basis weight, which enhances a sales promotion effect by increasing wound length per roll, and which is excellent in space-saving properties during carrying and storage.SOLUTION: In a toilet roll 10 in which two-ply toilet paper 10x is wound like a roll, roll tightness is in the range of 0.3-1.4 mm; a roll length is in the range of 63-103 m; a roll diameter DR is in the range of 105-134 mm; and roll density is 1.2-2.0 m/cm.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a toilet roll obtained by winding up toilet paper stacked on two plies.

Toilet papers that are packaged mainly in units of 4 rolls or 12 rolls are commercially available. Since these packages are bulky, the amount that can be carried at the time of purchase is limited, and the amount that can be purchased at one time is naturally limited. Storage space is also limited in homes, workplaces, and public facilities.
For this reason, toilet rolls have been developed in which the basis weight per sheet of toilet paper is reduced to 14 g / m ² or less and the winding length is increased (Patent Documents 1 and 2).
In addition, the applicant of the present application has developed a toilet roll having a longer winding length while improving the feeling of use by increasing the basis weight per sheet of toilet paper to be higher than 13 g / m ² (Patent Document 3).

JP 2006-087703 A JP 2013-208297 JP 2014-188342 A

However, when the basis weight of the paper is lowered, the strength is lowered and the feeling of use and bulkiness are lowered. On the other hand, if the calendar process is weakened to increase the bulk of the paper in order to compensate for these problems, there is a problem that the smoothness is inferior or the roll diameter becomes large and it is difficult to fit in the toilet paper holder.
Moreover, although the technique of patent document 3 is improving the feel, raising the basic weight of toilet paper, the softness of a roll is not examined.
Here, the softness of the roll is the tactile sensation when the toilet roll is held in the store, and does not directly reflect the softness of the sheet. However, since the roll cannot be unwound at the store and the softness of the sheet cannot be confirmed, even if the sheet itself is soft, if the roll is hard, the sheet seems to be hard and the purchase cannot be promoted. There is.
Therefore, the present invention provides a toilet roll that is excellent in sheet and roll softness without lowering the basis weight, lengthens the winding length per roll, enhances the sales promotion effect, and is excellent in space saving at the time of carrying and storage. With the goal.

The present inventors have improved the softness of the toilet paper sheet by, for example, embossing it into an appropriate uneven shape, and further ensuring the softness and winding length of the roll. We focused on density.
That is, even if embossing or the like is applied to soften the sheet, if the roll is wound too tightly, the roll becomes soft. On the other hand, if the roll is wound too weakly, the softness of the roll is improved, but the winding diameter is increased and the winding length is shortened.

In order to solve the above problems, the toilet roll of the present invention is a toilet roll obtained by winding a toilet paper layered on two plies into a roll shape, and has a winding hardness of 0.3 to 1.4 mm and a winding length of 63-103 m, winding diameter is 105-134 mm, winding density is 1.2-2.0 m / cm ² .

It is preferable to be embossed with a depth of 0.05 to 0.40 mm.
It is preferable that the emboss is a single emboss.
The toilet paper preferably contains 40 to 100% by mass of kraft pulp.
It is preferable to contain 0 to 60% by mass of waste paper pulp derived from milk carton.
Through a filter that cuts off UV light with a wavelength of 420 nm or less, and a whiteness UV-in conforming to ISO 2470 when the surface of the toilet paper is irradiated with a C light source defined by CIE (International Commission on Illumination) It is preferable that a difference Δ with a whiteness UV-cut based on ISO 2470 when the C light source is irradiated on the surface side of the toilet paper is 0.0 to 2.5 points.

  According to the present invention, a toilet roll excellent in sheet and roll softness without lowering the basis weight, lengthening the winding length per roll, enhancing the sales promotion effect, and being excellent in space saving during carrying and storage. Can be obtained.

It is a perspective view which shows the external appearance of the toilet roll which concerns on embodiment of this invention. It is sectional drawing which shows the embossing provided in the roll surface and the back surface. It is a figure which shows an example of a roll winding processing machine. It is a figure which shows the measuring method of emboss depth. It is another figure which shows the measuring method of emboss depth. It is a figure following FIG. It is a figure which shows an example of a machine winder. It is a figure which shows the picked-up image of the embossing recessed part on the roll surface side.

Preferred embodiments of the present invention will be described below, but these are given for illustrative purposes 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 obtained by winding a toilet paper 10x stacked on two plies into a roll shape, and the roll hardness is 0.3 to 1. 0.4 mm, the winding length (winding length) is 63 to 103 m, the winding diameter DR (outer diameter of the roll) is 105 to 134 mm, and the winding density is 1.2 to 2.0 m / cm ² .
The surface of the toilet paper 10x outside the roll is a roll surface (or toilet paper surface) 10a, and the surface inside the roll is a roll back surface (or toilet paper back surface) 10b.
As a method of adjusting the roll hardness and the winding density of the toilet roll to the above ranges, there is a method of adjusting the strength of winding the roll with a roll winder (particularly a surface type) while adjusting the basis weight and the paper thickness to a predetermined range. is there.

When the roll hardness of the toilet roll 10 is less than 0.3 mm, the softness of the roll is inferior. On the other hand, if the winding hardness exceeds 1.4 mm, the roll becomes too soft and is crushed after packaging with the film of the toilet roll 10, or the roll diameter DR of the roll becomes large and is difficult to fit in the toilet paper holder or the like. The winding hardness is preferably 0.4 to 1.2 mm, more preferably 0.5 to 0.9 mm.
Here, even if embossing or the like is applied to soften the sheet, if the roll is wound too hard, the softness of the roll decreases. On the other hand, if the roll is wound too weakly, the softness of the roll is improved, but the winding diameter DR is increased and the winding length is shortened. For these reasons, the winding hardness and winding density were defined as factors for achieving both roll softness and winding length.
The winding hardness of the toilet roll 10 is measured as follows using a compression tester (a handy compression tester KES-G5 manufactured by Kato Tech Co., Ltd.). First, the toilet roll 10 is placed on a hard table so that its axis is horizontal. Next, the KES-G5 compressor (area: 2.0 cm ² ) is pushed into the center of the roll surface of the toilet roll 10 from above at a speed of 10 mm / min. The indentation depth when the pressure at which the compressor pushes the roll is 0.5 gf / cm ² is T0, the indentation depth when the pressure is 50 gf / cm ² is Tm, and (Tm−T0) is the winding hardness. The measurement is performed 5 times, and the measurement results are averaged.

When the roll length of the toilet roll 10 is less than 63 m, the roll length per roll is shortened and space saving during storage cannot be achieved. When the roll length exceeds 103 m, the roll diameter DR exceeds 134 mm, which makes it difficult to fit in a toilet paper holder or the like.
The winding length is preferably 70 to 85 m, more preferably 73 to 78 m.

When the winding diameter DR is less than 105 mm, the winding length is also shortened to less than 63 m. When the winding diameter DR exceeds 134 mm, it is difficult to fit in a toilet paper holder or the like.
The winding diameter DR is preferably 108 to 125 mm, more preferably 113 to 119 mm.

The winding density is expressed by (winding length × number of plies) ÷ (cross-sectional area of roll). The cross-sectional area of the roll is represented by {the cross-sectional area of the outer diameter (rolling diameter DR) portion of the roll}-(the cross-sectional area of the core outer diameter portion). The core outer diameter DI (see FIG. 1) is the diameter of the center hole of the roll.
When the winding density is less than 1.2 m / cm ² , the winding diameter DR exceeds 134 mm, which makes it difficult to fit in a toilet paper holder or the like. When the winding density exceeds 2.0 m / cm ² , the softness of the sheet is inferior or the softness of the roll is inferior.
The winding density is preferably 1.4 to 1.8 m / cm ² , more preferably 1.5 to 1.7 m / cm ² .

When the basis weight per sheet of the toilet paper 10x exceeds 13 g / m ² and is 17 g / m ² or less, and the paper thickness is more than 0.6 mm / 10 sheets and 1.1 mm / 10 sheets or less, the winding hardness The winding length, the winding diameter DR, and the winding density are preferable because they are easily adjusted to the above ranges.
As a method of adjusting the basis weight and paper thickness of the toilet paper 10x per sheet to the above range, calendar conditions of the base paper web (paper thickness and specific volume after calendar processing, paper thickness difference before and after calendar processing) and embossing conditions Is specified.

When the basis weight per sheet of the toilet paper 10x is 13 g / m ² or less, or the paper thickness is 0.6 mm / 10 sheets or less, the strength decreases and the feeling of use (bulkiness) also decreases. There is a case. When the basis weight per piece of toilet paper 10x exceeds 17 g / m ² or the paper thickness exceeds 1.1 mm / 10 sheets, the toilet paper becomes thick, and the roll diameter DR of the roll obtained by winding the paper is 63 m or more. May exceed 134 mm, making it difficult to fit in the toilet paper holder.
The basis weight per sheet of the toilet paper 10x is more preferably 13.5 to 16.5 g / m ² , and further preferably 14.1 to 16.0 g / m ² . The thickness of the toilet paper 10x is more preferably 0.65 to 0.90 mm / 10, and further preferably 0.71 to 0.83 mm / 10.

<Emboss>
It is preferable that the toilet roll 10 (toilet paper 10x) of the present invention is embossed with a depth of 0.05 to 0.40 mm. In particular, single embossing is preferable.
As shown in FIG. 3, the single embossing is formed by pressing the embossing convex portion of the embossing roll 151 only from one surface of the toilet paper 10 x in which sheets are stacked on two plies.
FIG. 2 is a cross-sectional view showing the single emboss 2 provided on the toilet roll 10 (toilet paper 10x). In the example of FIG. 2, the toilet paper 10x is formed by stacking sheets on two plies, and the upper part of FIG. 2 corresponds to the roll surface 10a side. The embossing (single embossing) 2 in which the concave portion 2R appears on the surface of the toilet paper 10x against which the embossing roll 151 is pressed (the surface in FIG. 2) and the convex portion 2P appears on the back surface is formed.
2A shows a case where the emboss depth is deep, and FIG. 2B shows a case where the emboss depth is shallow.

In this case, the paper thickness t2 of the toilet paper 10x after the embossing process (this paper thickness reflects the distance between the non-embossed portion on the front surface of the toilet paper 10x and the convex portion 2P on the back surface) is the same. However, the sheet shown in FIG. 2 (a), in which the base paper is thinned to the paper thickness t1 by the calendar process and embossed so that the emboss depth D becomes deep, is softer and the texture is superior. This is considered to be because the embossed unevenness in FIG. 2A is higher in bulk with respect to the paper thickness of the base paper (lower in density), easily deforms, and improves the softness of the sheet. .
Further, in the case of FIG. 2 (a), since the embossing depth D is increased, it is necessary to reduce the paper thickness t1 per sheet and make the unevenness conspicuous. The softness of the sheet is improved due to the strong performance of the sheet.
On the other hand, if the surface of the toilet paper 10x is made smooth without providing an emboss, the surface is too smooth and the surface feels crisp and the sheet is inferior in softness. In addition, when the recessed portion 2R of the emboss is provided on the outer side of the roll (the roll surface 10a side) where water easily adheres to the toilet paper 10x when using the warm water washing toilet seat, the recessed portion 2R has a better tactile sensation than the protruding portion. The softness of the sheet is improved.
FIG. 8 shows a captured image of the embossed recess 2R on the roll surface 10a side.

When double embossing is applied instead of the single embossing of FIG. 2, each sheet on the front and back sides of the toilet paper 10x is embossed, and then the embossed convex surfaces of the respective sheets are plyed up. 2 plies. Therefore, the paper thickness t2 of the toilet paper 10x becomes too high, the winding density becomes low, and it may be difficult to ensure the winding length. Even in double embossing, if the embossing depth D is reduced, the paper thickness t2 is reduced, but the softness of the sheet may be inferior. Therefore, single embossing is preferable.
The means for ensuring the softness of the toilet paper (sheet) 10x is not limited to embossing, as long as it provides unevenness on the surface. Good. In this case, the depth of the unevenness is preferably in a range corresponding to an emboss depth D described later.

<Emboss depth D>
The emboss depth D is preferably 0.05 to 0.40 mm, more preferably 0.09 to 0.35 mm, and still more preferably 0.13 to 0.30 mm. When the emboss depth D is smaller than the above range, the degree of unevenness of the emboss becomes small, the bulk becomes low (the density becomes high), and it may be difficult to improve the softness of the sheet. When the embossing depth D exceeds the above range, the embossed irregularities become too prominent and the bulk becomes too high (the density becomes too low), the winding diameter DR exceeds 134 mm, and the toilet roll 10 is attached to the paper holder. It becomes difficult to install.

The emboss depth D is obtained by measuring the height difference of the emboss using a shape measuring laser microscope. The shape measurement laser microscope scans a laser light source, which is a point light source, into pixels obtained by dividing an XY plane in an observation field into a plurality of pixels through an objective lens, and detects reflected light for each pixel with 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 a focal point. By repeating the scanning in this way, an ultra-deep light amount image and a high / low image (information) focused on the whole can be obtained. Since the laser light source is a pinhole confocal optical system, the measurement accuracy is high.
As the shape measurement laser microscope, the product name “One-shot 3D measurement macroscope VR-3100” manufactured by KEYENCE can be used. The product name “VR-H1A” can be used as the laser microscope image observation / measurement / image analysis software. Measurement is performed under the conditions of a magnification of 12 and a visual field area of 24 mm × 18 mm. Note that the measurement magnification and the visual field area may be appropriately changed according to the required embossing size.

  First, as shown in FIG. 4, the longest part a of the peripheral edge fr of the emboss is obtained. Fig.5 (a) shows the height profile on XY plane by a shape measurement laser microscope, and it turns out that the height of the toilet paper surface is represented by shading. The dark colored portions in FIG. 5A indicate individual embosses 2, and the longest portion a of one emboss 2 can be distinguished from FIG. 5A. When a line segment A-B crossing the longest portion a is drawn, a height (measured cross section curve) profile of the emboss 2 is obtained as shown in FIG. Here, since the embossed convex portion (non-embossed portion) and the concave portion can be recognized by the color density of the XY plane image, the line segment AB can be determined so as to cross the adjacent portion of the convex portion and the concave portion. That's fine.

Here, the height profile in FIG. 5 (b) is a (measurement) cross-sectional curve S representing the unevenness of the actual toilet paper sample surface, but noise (fiber lumps on the surface of the toilet paper or fibers are present). In addition, it includes a steep peak due to a beard-like shape or a portion having no fiber), and it is necessary to remove such a noise peak when calculating the height difference of the unevenness.
Therefore, as shown in FIG. 6, a “contour curve” W is calculated from the cross-sectional curve S of the height profile, and two inflection points P1 and P2 that are convex upward of the contour curve W, and the inflection The minimum value sandwiched between the points P1 and P2 is obtained and set as the minimum value Min of the depth. Further, the average value of the depth values of the inflection points P1 and P2 is set as the maximum value Max.
In this way, the emboss depth D = maximum value Max−minimum value Min. The distance (length) on the XY plane between the inflection points P1 and P2 is defined as the length of the longest portion a. Note that the “contour curve” is λc: 800 μm from the cross-sectional curve (where λc is a “filter that defines the boundary between the roughness component and the waviness component” described in JIS-B0601 “3.1.1.2”). It is a curve obtained by removing the surface roughness component with a low-pass filter. If λc is set to be equal to or larger than the interval P1 between adjacent embosses (this is referred to as an emboss pitch), the peak may be recognized as noise. Therefore, λc is set to be less than the emboss pitch. For example, when the emboss pitch is 800 μm or less, λc is set to 250 μm, for example. The P1 interval between adjacent embosses is the interval between two P1s when P1 and P2 are similarly obtained for the next emboss connected to the left or right in FIG. 6 and aligned with P1, P2, and P1 between adjacent embosses. is there.

Similarly, the emboss depth D is also measured for the longest portion b in the direction perpendicular to the longest portion a in FIG. 5A, and the larger value of the emboss depths D of the longest portions a and b. Is adopted as the emboss depth D. The above measurement is performed for any ten embosses 2 on the surface 10a of the toilet paper 10x, and the average value is adopted as the final emboss depth D.
Further, the product (a × b) of the longest part a and the longest part b is obtained as the area S of the emboss 2. For the longest part a and the longest part b, a value obtained by averaging the values of individual a and b for the ten embosses 2 on the surface 10a of the toilet paper 10x described above is used.
The embossed area S is preferably 0.4 to 7.0 mm ² , more preferably 1.5 to 6.5 mm ² , still more preferably 2.5 to 6.0 mm ² , and most preferably 3.5 to 5.5 mm. ² . If the embossed area S is less than 0.4 mm ² , the embossing is too small and the cosmetics may be inferior. On the other hand, when the embossed area S exceeds 7.0 mm ² , the embossing is too large, and the cosmetics may be similarly inferior.

When the emboss depth D is measured, the measurement surface is on the surface 10a side, whether it is single emboss or double emboss.
Further, when selecting any ten embosses 2 with the emboss depth D and the emboss area S, the roll of the toilet roll 10 is started from the end of the outer roll of the toilet roll 10 (position where the toilet paper starts to be used). Measure at the part corresponding to 20% of the length. For example, when the winding length is 75 m, the measurement is performed at a portion of 75 m × 20% = 15 m from the end. In addition, when the 20% portion of the winding length hits the perforation, the outer winding side of the perforation is measured.

FIG. 3 shows an example of a roll winding machine 150. The base paper roll is preliminarily made into two plies by a ply machine and calendered to become a raw fabric 4 (paper thickness t1 of each sheet). This raw fabric 4 is set on a roll winding machine 150 and subjected to a single embossing process by an embossing unit (embossing roll) 151, and then wound around a wide toilet paper roll 10W having the above winding diameter by a winding mechanism 153. Taken. Thereafter, the original roll 10W is cut into a predetermined width (114 mm or the like) to form the toilet roll 10.
The roll winding machine 150 can be roughly classified into two types: a surface method and a center method. The surface method is a method in which the roll to be wound is wound while being supported by a plurality of other drive rolls from the outside. The wound toilet roll 10 is easy to control the winding diameter, and the production speed becomes higher. The center method is a method of winding by driving a shaft passing through the center of the winding roll. The wound toilet roll 10 is a relatively soft product and is suitable for a product with delicate embossing. In the present invention, any method can be used for winding, but the surface method is preferred.
Note that the machine winder 100 may be incorporated in the roll winder 150, and the roll-up machine may perform the ply-up, calendar processing, and embossing in this order. Alternatively, each hygienic thin paper sheet may be plyed up after the calendar process and embossed.

The emboss depth D can be controlled by appropriately adjusting the nip width of the rubber roll (see FIG. 3) facing the emboss roll 151. The nip width is preferably 20 to 45 mm, more preferably 25 to 42 mm, and still more preferably 30 to 39 mm, although it varies depending on roll characteristics. If the nip width exceeds 45 mm, the embossing becomes too strong and the difference between the front and back becomes large, or the paper thickness becomes high and the roll diameter DR of the roll becomes large. On the other hand, when the nip width is less than 20 mm, the embossing becomes weak and the softness of the sheet may be inferior. The nip width can be measured using carbon paper. As a measuring method, first, the nip of the embossing roll is escaped, and carbon paper and general copy paper are stacked and set. Next, a nip is put on the embossing roll. Then, let the nip escape and remove the carbon paper and copy paper. Since the color of the carbon paper where the nip is applied by the embossing roll is transferred to the copy paper, the nip width can be measured.
The embossing depth D can be adjusted by narrowing the nip width if the embossing roll is deep, and increasing the nip width if the embossing roll is shallow.

  At the same time, the roll winder can perform printing, embossing, perforation, tail sealing, and cutting with a predetermined width (114 mm, etc.), and the toilet roll 10 can be manufactured. Furthermore, the package body of a toilet roll can be manufactured by film packaging processing after that.

The specific volume of the toilet paper is preferably 4.0 to 6.5 cm ³ / g.
When the specific volume is less than 4.0 cm ³ / g, the softness of the sheet may be poor, or the bulk (bulk height) may be reduced, resulting in poor moisture absorption. On the other hand, when the specific volume exceeds 6.5 cm ³ / g, the bulk (bulk height) of the sheet increases, but the paper thickness after embossing increases and the winding diameter may increase. The specific volume is preferably 4.3 to 6.1 cm ³ / g, more preferably 4.7 to 5.6 cm ³ / g.

DMDT (Dry Machine Direction Tensile strength) is the tensile strength in the vertical direction when drying toilet paper (double-layer sheets) according to JIS P8113, and DCDT (Dry Cross Direction Tensile strength is the tensile strength in the horizontal direction when drying. DMDT is preferably 2.2 to 5.0 N / 25 mm, more preferably 2.5 to 4.5 N / 25 mm, still more preferably 2.7 to 4.0 N / 25 mm, and DCDT is preferably 0. .80 to 2.2 N / 25 mm, more preferably 0.9 to 1.9 N / 25 mm, and still more preferably 1.0 to 1.6 N / 25 mm.
If DMDT and DCDT are less than the above values, they may be easily shaken and not suitable for practical use. If DMDT and DCDT are higher than the above values, the sheet becomes hard and the softness of the sheet may be impaired.
The flow direction of toilet papermaking is defined as “longitudinal direction”, and the direction perpendicular to the flow direction is defined as “lateral direction”.

The water absorption based on the old JIS S3104 of the toilet paper (two-layered sheet) is preferably 7.0 seconds or less, more preferably 5.0 seconds or less, and even more preferably 3.0 seconds or less. The faster the water absorption, the better, but if it exceeds the above range, the water absorption may be inferior.
The ease of loosening based on JIS-P4501 when the toilet paper is peeled into one sheet is preferably 60 seconds or less, more preferably 50 seconds or less, and even more preferably 40 seconds or less. The ease of unraveling should be fast, but if it exceeds the above range, the water disintegration property in the toilet may be inferior.

Toilet paper may consist of 100% by weight of wood pulp, and may include waste paper pulp, non-wood pulp, and deinked pulp. In order to obtain the target quality, the content of NBKP (conifer bleached kraft pulp) is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, and further preferably 5 to 15% by mass. The content of LBKP (hardwood bleached kraft pulp) is preferably 30 to 90% by mass, more preferably 40 to 80% by mass, and still more preferably 50 to 70% by mass.
Moreover, the content rate of the waste paper pulp derived from the milk carton (milk pack) is preferably 0 to 60% by mass, more preferably 10 to 50% by mass, and further preferably 20 to 40% by mass. Preferably, it is 40-100 mass%, More preferably, it is 50-90 mass%, More preferably, it is 60-80 mass%.
Waste paper pulp derived from milk cartons (milk cartons) is mainly softwood pulp and has the advantage of ensuring the strength of toilet paper. On the other hand, quality variation is large, and if the content is too high, the quality of the product will be affected. The content is preferably in the above range.
Pulp produced from Eucalyptus eucalyptus represented by Eucalyptus genus Grandis and Eucalyptus globulus is preferred as the grade of LBKP.

Further, 25 parts by mass or less of deinked pulp derived from used newspaper or magazine waste paper can be blended with 100 parts by mass of waste paper pulp derived from NBKP, LBKP, or milk carton. In addition, when 25 mass parts of deinked pulp is blended, the content of deinked pulp in the toilet paper (sheet) is 25 mass parts / (100 mass parts + 25 mass parts) × 100 = 20 mass%. The content of the deinked pulp is 0 to 20% by mass, preferably 0 to 10% by mass, more preferably 0 to 5% by mass or less, and most preferably 0% by mass. Since deinked pulp is also waste paper, the quality will vary greatly. Moreover, deinked pulp usually contains a fluorescent dye, and if its content exceeds 20% by mass, it will contain a lot of fluorescent dye, which is not preferable.
If the deinked pulp contains a fluorescent dye, the difference Δ between the whiteness value of the toilet paper (sheet) under the UV-in condition and the whiteness value under the UV-cut condition becomes large. Here, UV-in is a whiteness degree based on ISO 2470 when a C light source (including ultraviolet light) defined by CIE (International Commission on Illumination) is irradiated on the sheet surface side. UV-cut is the whiteness based on ISO 2470 when a C light source is irradiated on the sheet surface side through a filter that cuts ultraviolet light having a wavelength of 420 nm or less. Difference Δ = (whiteness UV-in) − (whiteness UV-cut).
The difference Δ is preferably 0.0 to 2.5 points, more preferably 0.0 to 1.5 points, still more preferably 0.0 to 1.0 points, and most preferably 0.0 to 0.5 points. It is. The whiteness can be measured using a high-speed spectrophotometer CMS-35SPX manufactured by Murakami Color Research Laboratory Co., Ltd. according to ISO 2470.

  In addition, in order to ensure an appropriate strength for the toilet paper, raw materials can be blended by ordinary means, and the strength can be adjusted by beating the pulp fibers. As the beating to obtain the target quality, 0 to 150 ml, more preferably 0 to 100 ml, and more preferably 10 to 50 ml of a Canadian standard freeness measured according to JIS-P8121 is used for commercially available virgin pulp. Reduce water content. Moreover, it is preferable not to use a wet paper strength enhancer.

Toilet paper can be made by blending softwood kraft pulp and hardwood kraft pulp having a certain range of fiber length and fiber roughness in a specific range when virgin raw materials are used for the stock. Additives to paper stocks include softeners including debonder softeners, bulking agents, dyes, dispersants, dry paper strength enhancers, drainage improvers, pitch control agents, absorbency, depending on the required quality of the final product. An improver or the like can be used.
When using waste paper raw material as toilet paper, the same treatment as in the case of the virgin is performed.
Details of the method for manufacturing toilet paper will be described later.

  Toilet paper can be manufactured, for example, in the following order: (1) papermaking and creping, (2) ply-up and calendaring with a machine winder, and (3) embossing and roll winding. Of these, (3) has already been described and will be omitted.

(1) Papermaking and creping,
First, a web is made from the above-mentioned stock on a wire part of a known paper machine, and moved to the felt of the press part. Examples of the wire part type include a round net type, a long net type (Ford Linear) type, a suction breast type, a short net type, a twin wire type, and a crescent former type.
Then, the web is mechanically compressed with a suction pressure roll or a pressure roll or a press roll without suction, or dehydrated by a dehydration method such as aeration drying with hot air. The suction pressure roll or the pressure roll without suction is also used as a means for moving the web from the press part to the Yankee dryer.

The web moved to the Yankee dryer is dried by a Yankee dryer and a Yankee dryer hood, then creped by a creping doctor, and taken up by a reel part.
Creping (creating a wavy wrinkle called crepe) is to mechanically compress paper in the longitudinal direction (the sheet running direction on the paper machine). When the toilet paper web is manufactured, the web on the Yankee dryer is peeled off by the creping doctor and wound on the reel part. The speed difference between the Yankee dryer and the reel part (reel part speed ≤ Yankee dryer speed) ), A crepe is formed by a creping doctor.
The quality required for the toilet paper, that is, bulk (bulk feeling), softness, water absorption, surface smoothness, aesthetics (crepe shape), and the like depend on the speed difference. Although depending on conditions such as the speed difference, the basis weight of the web on the reel after creping is approximately 14 to 20 g / m ² , which is heavier than the basis weight of the web on the Yankee dryer before creping. The basis weight is preferably 14 to 18 g / m ² . If it exceeds the above range, the strength may be high and the paper may be stiff. If it is less than the above range, the strength may be weak and easy to tear.

Here, the crepe rate based on the speed difference between the Yankee dryer and the reel is defined by the following equation.
Crepe rate (%) = 100 × (Yankee dryer speed (m / min) −reel speed (m / min)) ÷ reel speed (m / min)
The quality and operability are largely determined by the creping conditions, and the operating conditions that optimize the creping conditions are important for those skilled in the art. In the present invention, the crepe rate when producing toilet paper is preferably 10 to 50%, more preferably 15 to 40%, and most preferably 20 to 35%.

(2) Ply-up and calendar processing by machine winder FIG. 7 shows an example of a machine winder 100. As described above, two reels 1 wound up by the reel part after creping are set on the machine winder 100, and the two reels 1 are overlapped with each other so that the Yankee surface is on the outside. At this time, the calendar processing is performed in two stages in order of the calendar machine 101 of the first stack and the calendar machine 102 of the second stack after the ply-up. However, it is also possible to perform calendar processing before ply-up or using an on-machine calendar.
The thickness of the toilet paper before embossing (after calendaring) is preferably 0.55 to 1.15 mm / 10, and more preferably 0.60 to 0.80 mm / 10. Moreover, the specific volume of the toilet paper in the raw fabric roll 4 before the embossing process (after the calendar process) is preferably 3.4 to 6.5 cm 3 / g, more preferably 3.7 to 6.0 cm 3 / g, more preferably It is set to 4.0 to 5.5 cm3 / g.

In addition, the paper thickness of the toilet paper before embossing is the paper thickness in the original fabric roll 4 after calendar processing in FIG. 7, and corresponds to the paper thickness t1 in FIG. However, as will be described later, since the paper thickness is a value measured with a measurement load of 3.7 kPa, it does not accurately reflect the paper thickness t1 in FIG.
The thickness of the toilet paper after embossing shown in Tables 1 and 2 corresponds to the paper thickness t2 in FIG. 2, but is a value measured at a measurement load of 3.7 kPa, so it accurately reflects the paper thickness t2. It was n’t.
On the other hand, the emboss depth D is a value measured when the emboss is not compressed. Accordingly, the emboss depth D is significantly larger than a value calculated from the paper thicknesses t1 and t2 (this value is a value obtained by compressing the emboss with a measured load of 3.7 kPa).

Each of the calender machines 101 and 102 is preferably composed of two metal rolls, but one of the two rolls may be an elastic roll so that soft calender processing can be performed.
The linear pressure of the calendar is preferably 3.0 to 8.0 kgf / cm, more preferably 4.0 to 7.0 kgf / cm. When the linear pressure exceeds the above range, the bulk becomes small and the softness may be inferior. Further, if the wire thickness is less than the above range, the bulk becomes large and the roll diameter DR of the roll becomes large. The linear pressure is preferably higher than the first stack.
During calendar processing, the draw can be adjusted appropriately. The draw between the reel 1 before ply-up and the original fabric 4 after the calendar process is preferably 100 to 110%.
By the calendar process and the draw adjustment, the paper thickness can be managed to exceed 0.6 mm / 10 sheets and to 1.1 mm / 10 sheets or less, while maintaining the basis weight exceeding 13 g / m ² and 17 g / m ² or less.

It is preferable that the basis weight of the web of the raw fabric 4 after the calendar process and before the embossing process is 13.5 to 18.0 g / m ² per sheet. Since the web is slightly stretched and the basis weight is lowered in the roll winding process described later, it is preferably 13.5 to 18.0 g / m ² slightly higher than the target basis weight of the toilet roll 10 in the final form, and more preferably 14 .5 to 17.5 g / m ² . In addition, since the web is slightly stretched in the roll winding process, the paper thickness is reduced in the same manner as the basis weight before and after winding, but the embossing can be adjusted to the target paper thickness of the final form toilet roll 10.

  The raw fabric 4 after the calendar process is embossed by, for example, the roll winder 150 shown in FIG.

  It goes without saying that the present invention is not limited to the above-described embodiment, and extends to various modifications and equivalents included in the spirit and scope of the present invention.

  The content ratio of the pulp composition is (mass%) NBKP 10%, LBKP 60%, and waste paper derived from milk carton 30%. Toilet paper and toilet rolls were produced.

The following evaluation was performed.
Longitudinal tensile strength DMDT during drying and transverse tensile strength DCDT during drying: Based on JIS P8113, the maximum load until breakage was measured in units of N / 25 mm for toilet paper (two sheets).
Basis weight: measured based on JIS P8124 and converted per sheet.
Paper thickness: 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 and a probe diameter of 30 mm. A sample was placed between the probe and the measurement table, and the gauge was read when the probe was lowered at a speed of 1 mm or less per second. For the web before the calendar process, measurement is performed with 10 sheets stacked. After the calendar process (after ply-up) and for the roll, 5 sheets (5 sets) of toilet paper stacked with 2 plies of sheets are stacked. I went. The measurement was repeated 10 times and the measurement results were averaged. Then, the average value obtained per time was divided by the number of sheets to obtain the paper thickness per sheet.

Specific volume: The thickness per sheet was divided by the basis weight per sheet, and expressed as a volume cm ³ per unit g.
Roll winding diameter DR: Measured using a Diameter Rule manufactured by Muratec KDS Corporation. The measurement measured 10 rolls and averaged the measurement results.
The roll winding hardness, winding density, and embossing depth were measured by the methods described above.

Sensory evaluation was performed by 20 monitors. The evaluation standard was a perfect score. If the evaluation criteria is 3 points or more, it is good.
The basis weight, tensile strength, thickness, specific volume, winding hardness, winding density, and emboss depth are measured under the temperature and humidity conditions specified in JIS-P8111 (23 ± 1 ° C, 50 ± 2% RH). ) Was performed after maintaining the equilibrium state.

  The obtained results are shown in Tables 1 and 2.

  As is clear from Tables 1 and 2, in each example where the roll hardness, roll length, roll diameter, and roll density of the toilet roll are within a predetermined range, the softness of the sheet and roll without lowering the basis weight. The winding length per roll could be increased while improving both.

On the other hand, the softness of the sheet was excellent with embossing at an appropriate depth, but in the case of Comparative Example 1 in which the winding length was less than 63 m, the winding diameter was less than 105 mm and the frequency of roll replacement was increased. .
The softness of the sheet was excellent with embossing at an appropriate depth, but in the case of Comparative Example 2 where the winding length exceeded 105 m, the winding diameter exceeded 134 mm, the roll diameter increased, and the toilet paper holder It became difficult to fit.
In the case of Comparative Example 3 in which the emboss depth D is less than 0.05 mm and the winding hardness is less than 0.3 mm, the degree of unevenness of the emboss becomes small and the bulk becomes low (density becomes low), and the softness of the sheet and the roll Inferior.

  In the case of Comparative Example 4 in which the emboss depth D exceeds 0.40 mm and the winding hardness exceeds 1.4 mm, the unevenness of the emboss becomes too remarkable and the bulk becomes too high (the density becomes too low). The diameter exceeded 134 mm, and the roll diameter increased, making it difficult to fit in the toilet paper holder.

In the case of Comparative Example 5 where the toilet paper is wound too weakly (softly) with a roll winder and the winding hardness exceeds 1.4 mm, the roll diameter of the toilet roll exceeds 134 mm, and the roll diameter increases to fit in the toilet paper holder. It became difficult.
In the case of Comparative Example 6 in which the toilet paper was too strongly (hardly) wound with a roll winder and the winding hardness was less than 0.3 mm, the winding diameter was 105 mm, and the roll softness was inferior.
In the case of Comparative Example 7 where the emboss depth D was less than 0.05 mm, the degree of unevenness of the emboss was reduced, the bulk was lowered (the density was lowered), and the softness of the sheet was inferior. Moreover, in the case of the comparative example 7, since the winding length exceeded 105 m and the winding diameter exceeded 134 mm, the roll diameter became large and it was difficult to fit in the toilet paper holder.

  In addition, when the commercial products 1 to 3 were evaluated in the same manner, the winding length was less than 63 m, and the frequency of roll replacement increased.

2 Emboss 10 Toilet roll 10x Toilet paper D Emboss depth

In order to solve the above problems, the toilet roll of the present invention is a toilet roll obtained by winding a toilet paper layered on two plies into a roll shape, and has a winding hardness of 0.3 to 1.4 mm and a winding length of 63～103M, winding diameter 105～134Mm, winding density of Ri 1.2~2.0m / cm ² der, the toilet 17 g / ^{m 2} basis weight of the sheet per sheet exceeds 13 g / ^{m 2} paper or less, the vertical tensile strength DMDT during drying as 2 ply of the toilet paper, Ru 2.2~5.0N / 25mm der.

Claims (6)

A toilet roll obtained by winding a toilet paper layered on two plies into a roll,
A toilet roll having a winding hardness of 0.3 to 1.4 mm, a winding length of 63 to 103 m, a winding diameter of 105 to 134 mm, and a winding density of 1.2 to 2.0 m / cm ² . The toilet roll according to claim 1, which is embossed with a depth of 0.05 to 0.40 mm. The toilet roll according to claim 1 or 2, wherein the emboss is a single emboss. The toilet roll according to any one of claims 1 to 3, wherein the toilet paper contains 40 to 100% by mass of kraft pulp. The toilet roll as described in any one of Claims 1-4 which contains 0-60% of the waste paper pulp derived from a milk carton. Through a filter that cuts off UV light with a wavelength of 420 nm or less, and a whiteness UV-in conforming to ISO 2470 when the surface of the toilet paper is irradiated with a C light source defined by CIE (International Commission on Illumination) The difference Δ with whiteness UV-cut based on ISO 2470 when the surface of the toilet paper is irradiated with the C light source is 0.0 to 2.5 points. 6. Toilet roll as described in