Toilet roll

Abstract

To provide a toilet roll in which patterns superior in design properties are visible while being a long article, and furthermore wrinkles and kinks are reduced, and thereby surface smoothness is easy to feel.SOLUTION: A toilet roll is provided by making toilet tissue paper of 2-ply into a roll and having a roll diameter of 90-120 mm. In the toilet tissue paper, irregularities by embossing are provided, patterns formed by halftone dot printing and solid typesetting are printed on one side, a ratio of a total area of a pattern portion is 8-20%, a ratio of a total area of a halftone dot portion is 6.0% or more, a ratio of a total area of a solid portion is 4.0% or less, and a paper thickness of 1-ply is 60-90 μm. The toilet tissue paper is rolled around a paper tube of 65-90 m with a roll density of 0.83-2.05 so that the surface with the patterns printed thereon may become an outer layer side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a toilet roll in which toilet paper is wound into a roll. [Background technology]

[0002] Toilet rolls are a daily commodity, and toilet spaces are Spe Because of limited supply, a long roll length is an important factor in consumer purchasing decisions.

[0003] The typical roll length of toilet rolls for general household use is around 25 m for 2-ply (also called double) and around 50 m for 1-ply (also called single); however, in recent years, longer rolls 1.5 to 3 times longer are becoming more common (see Patent Document 1 below).

[0004] In order to make such long toilet rolls into a roll diameter that can be used in commonly used household toilet paper holders, the toilet paper needs to have a low basis weight, be thin in thickness, and be tightly wound.

[0005] Incidentally, among conventional toilet rolls of about 25 m in two-ply or about 50 m in one-ply, there are toilet rolls with floral patterns or the like printed on them with ink (see Patent Document 2 below). These toilet rolls have excellent design. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2018-064664 A [Patent Document 2] JP 2008-188070 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the case of long toilet rolls, the toilet paper needs to have a low basis weight, be thin in thickness, and be tightly wound, as described above, so when a pattern is printed on it, the ink can bleed through to the back, causing unnecessary bleeding of the ink on the back side.

[0008] Furthermore, since ink is applied to a thin base paper and the paper is tightly wound, the paper is prone to breakage during production, and wrinkles and kinks are easily formed.

[0009] Furthermore, because the ink is applied to a thin base paper, the ink-applied portion has a noticeable hard feel, which can make it difficult to feel smooth.

[0010] Furthermore, because toilet rolls are made up of multiple layers of toilet paper, in long products the pattern of the toilet paper underneath is too visible, which can prevent the desired design from being achieved.

[0011] Therefore, a main object of the present invention is to provide a long toilet roll that is easy to manufacture, has no wrinkles or kinks, has a design that is visually recognizable, and has a smooth surface. [Means for solving the problem]

[0012] The first means for solving the above problem is: A toilet roll having a roll diameter of 90 to 120 mm, which is made of two plies of toilet paper. The toilet roll has an embossed texture, one side of which is printed with a pattern formed by dot printing and solid printing, the ratio of the total area of ​​the pattern being 8-20%, the ratio of the total area of ​​the dots being 6.0% or more, and the ratio of the total area of ​​the solid parts being 4.0% or less, and the toilet roll has a paper thickness of 60-90 μm per ply, and is wound around a paper tube with a winding density of 0.83-2.05 and a winding length of 65-90 m, with the surface on which the pattern is printed being the outer layer.

[0013] The second method is The toilet paper is the toilet roll according to the first aspect, in which the ten-point average roughness [RzJIS] of the outer layer side is 0.025 to 0.320 mm.

[0014] The third method is The toilet paper is a two-ply double-embossed toilet paper made of two sheets, one of which has a concave portion on one side and a convex portion on the other side formed by embossing, laminated with the concave portions on the outside, the toilet roll being related to the first or second means described above.

[0015] The fourth measure is The toilet roll according to the first to third aspects has a roll density of 0.1 to 0.3.

[0016] The fifth measure is: The toilet roll according to any one of the first to fourth aspects has a void ratio of 3 to 20%. Effect of the Invention

[0017] According to the present invention, a toilet roll is provided which, although being a long product, is easy to manufacture, has no wrinkles or kinks, has a visually recognizable design, and has a smooth surface. [Brief description of the drawings]

[0018] [Figure 1]FIG. 1 is a perspective view of a toilet roll according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram for explaining a procedure for measuring whiteness and color difference according to the present invention. [Diagram 3] FIG. 2 is a diagram for explaining design printing according to the present invention. [Figure 4] FIG. 2 is a diagram for explaining an example of an embossing pattern according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Next, the toilet roll according to the present invention will be described with reference to the drawings. As shown in Fig. 1, the toilet roll 1 according to the present invention is formed by winding two plies of strip-shaped toilet paper 10 around a paper tube (also called a tube core) 20 into a roll.

[0020] The roll diameter L2 (diameter) of the toilet roll 1 according to the present invention is 90 to 120 mm, preferably 100 to 119 mm. The roll diameter L2 of the toilet roll is set to 120 mm or less in JIS P 4501, and a holder for setting a general toilet roll is made based on this 120 mm. The toilet roll according to the present embodiment has a roll diameter of 120 mm or less and can be set in a general holder. Here, the roll diameter L2 is a value measured using a diameter rule manufactured by Muratec KDS Co., Ltd. or an equivalent machine. The measured value is an average value of measurements taken at three different positions in the width direction. The roll width L1 of the toilet roll according to the present embodiment is not limited, but is preferably 100 to 130 mm. The outer diameter L3 of the cardboard core is also not limited, but is 34 to 42φ mm.

[0021] The toilet roll according to the present invention is characterized in that it has unevenness due to embossing, one side of which is printed with a pattern formed by halftone dot printing and solid printing, the ratio of the total area of ​​the pattern part being 8-20%, the ratio of the total area of ​​the halftone dot parts being 6.0% or more, and the ratio of the total area of ​​the solid parts being 4.0% or less, and the toilet paper having a paper thickness of 60-90 μm per ply is wound around a paper tube with a winding density of 0.83-2.05 and a winding length of 65-90 m, with the surface printed with the pattern being the outer layer side.

[0022] By having these configurations, the toilet roll according to the present invention is less likely to cause ink strike-through when a pattern is printed, is less likely to cause unnecessary ink bleeding on the back side, and is less likely to break during production. In addition, the toilet roll is free of wrinkles and kinks, and the halftone dot printed area, solid printed area, and the pattern of the toilet paper underneath are not excessively visible, resulting in a distinctive design. In addition, the hard texture of the ink-applied area is less noticeable, making it easy to feel smooth.

[0023] The toilet roll according to the present invention has a paper thickness of 60 to 90 μm per ply of the toilet paper wound thereon. It is preferably 60 to 85 μm. When the paper thickness of one ply is 60 to 90 μm, the toilet paper can have sufficient strength and softness, and when a length of 65 to 90 m is wound around a paper core, the roll diameter L2 (diameter) can be easily set in the range of 90 to 120 mm. In addition, under the conditions for pattern printing according to the present invention, there is no ink strike-through or unnecessary ink bleeding on the back surface, and paper breaks during production are unlikely to occur.

[0024] The paper thickness is measured by conditioning the test piece under the conditions of JIS P 8111 (1998) for 8 hours or more, and then measuring the thickness of one ply using a dial thickness gauge (thickness measuring device) "PEACOCK G type" (manufactured by Ozaki Manufacturing Co., Ltd.) under the same conditions. Specifically, after making sure that there is no dirt or dust between the plunger and the measurement table, the plunger is lowered onto the measurement table, the dial thickness gauge's scale is moved to set the zero point, and then the plunger is raised and the sample is placed on the measurement table, but is not pressed down. The plunger terminal is made of metal, and the circular flat surface with a diameter of 10 mm is made to contact the paper surface perpendicularly, and the load during the paper thickness measurement is about 70 gf. The paper thickness is the average value obtained by performing 10 measurements. The same measurement is also performed if the toilet paper has unevenness due to embossing. In this case, the measurement is performed so that one recess is entirely within the range of the measurement table. The crushing of the unevenness during the measurement may be ignored. In this paper thickness measurement, the difference in paper thickness caused by the collapse of the recesses can be ignored.

[0025] The toilet paper according to the present invention has a basis weight of 11.5 to 16.0 g / m 2 It is desirable to set the range to 12.0 to 15.5 g / m 2 More preferably, the density is 12.0 to 15.0 g / m 2 12.5~16.0g / m 2 In the toilet roll according to the present invention, the dry tensile strength and the wet tensile strength may be appropriately adjusted by a known method within a range that does not impede the effects of the present invention.

[0026] The ten-point mean roughness [RzJIS] of the outer layer of the toilet paper according to the present invention is preferably 0.025 to 0.320 mm. More preferably, it is 0.025 to 0.315 mm. When the ten-point mean roughness [RzJIS] is in this range, print rubbing is unlikely to occur, print clarity is good, and it is easy to obtain a product with excellent design. In particular, since the print clarity is good, the design is unlikely to deteriorate even in a range where the ink application range is small, such as 8 to 9.5% of the total area of ​​the pattern part and 6.0 to 7.0% of the total area of ​​the dot part. The ten-point mean roughness [RzJIS] is measured using a one-shot 3D measuring macroscope VR-3200 manufactured by Keyence Corporation or an equivalent device, and image analysis software "VR-H2A" or an equivalent software. The measurement is performed under the conditions of a magnification of 12 times and a field of view area of ​​24 mm x 18 mm. However, the magnification and the field of view can be changed as appropriate depending on the size of the embossment (recess). The ten-point average roughness [RzJIS] is measured by taking a three-dimensional image and analyzing the data at a position that avoids the pattern part where ink is applied, and at any position if there is no embossing, or at a position that avoids the recesses if there are recesses due to embossing, and especially at the position of the middle part between adjacent recesses in the case of a regularly arranged recess. The profile line measured in the line roughness measurement is measured and analyzed in the paper flow direction. The measurement parameter is the "composite parameter RzJIS". In addition, the measurement point on the outermost surface of the toilet roll reflects the smoothness of the toilet roll surface, but the accuracy decreases, so it is an arbitrary position within the range of 29 to 31% from the outermost end at the beginning of use. In addition, the measurement value is the average value of 10 points, and the measurement sample can be fixed to the measurement table in a way that does not affect the measurement value.

[0027] In addition, the toilet paper according to the present invention preferably has a crepe number of 35 to 50 / 10 mm. The crepe number is 35 to 50 / 10 mm, preferably 37 to 48 / 10 mm, and more preferably 39 to 45 / 10 mm. This crepe number makes the surface feel smoother, and in particular, in the pattern printing according to the present invention, the hard feel of the ink-applied portion is less noticeable, making the surface feel smoother overall. The crepe number can be adjusted by the crepe rate during the manufacture of the base paper, the presence or absence of calendaring, and the calendar pressure. The crepe number is measured using a one-shot 3D measuring macroscope VR-3200 manufactured by Keyence Corporation or an equivalent device, and image analysis software "VR-H2A" or an equivalent software. The measurement is performed under conditions of a magnification of 12 times and a field area of ​​24 mm x 18 mm. However, the magnification and field area can be appropriately changed depending on the size of the embossment (recess). The number of crepes is measured by taking a 3D image and analyzing the data at a position that avoids the pattern part where ink is applied, and at any position if there is no embossing, or at a position that avoids the recesses due to embossing if there are recesses, and especially at the middle part between adjacent recesses if the recesses are regularly arranged. The profile line to be measured in the line roughness measurement is specified to be perpendicular to the paper flow direction, and the measurement and analysis are performed. The measurement parameter is "line roughness". The number of crests of the obtained measured cross-sectional curve over a measurement distance of 10 mm is the number of crepes. In addition, the measurement point on the toilet roll is an arbitrary position within a range of 29 to 31% from the outermost end at the start of use, since the outermost surface of the toilet roll reflects the smoothness of the toilet roll surface but the accuracy decreases. In addition, the measurement value is the average value of 10 points, and the measurement sample can be fixed to the measurement table in a manner that does not affect the measurement value.

[0028] The toilet roll according to the present invention has a pattern printed on one side of the toilet paper, and is wound around a paper tube so that the side on which the pattern is printed is the outer layer. In other words, the toilet roll according to the present invention has a pattern only on the side located on the outer layer. By printing the pattern on the outer layer side, the pattern can be directly seen from the outside, and in particular, even if the pattern is printed lightly like halftone printing, it is easily visible.

[0029] In addition, since a toilet roll is made of multiple layers of toilet paper, if there is more than one layer (two plies), if the pattern of the lower layer is visible, the pattern of the lower layer and the pattern of the outer surface may be mixed and visible. However, since the toilet paper of the present invention is particularly made of two plies, an unprinted layer is interposed between the inner layer ply, so if a pattern is formed only on the outer layer within the range of paper thickness specified in the present invention, the pattern on the outer surface can be fully visible, while the pattern of the lower layer is difficult to see. This is even more true if the basis weight is as described above. In order to have a pattern only on the outer layer side, the paper can be wound with the printed surface facing outward.

[0030] The patterns according to the present invention are formed by printing, and do not include those colored at the papermaking stage by supplying dyes to the papermaking raw materials. The specific design of the pattern is not particularly limited. For example, one or several patterns may be appropriately selected and drawn from among plants such as flowers, trees, and grass; living things such as people, animals, fish, shellfish, and insects; nature such as mountains, rivers, oceans, clouds, forests, and woods; planets and satellites such as the moon, sun, and stars; and man-made objects such as cars, airplanes, and trains. The area of ​​one pattern is not particularly limited, but may be 102 mm 2 ~918mm 2 If the amount of ink is within this range, the design will be easily recognized and will be perceived as having excellent design, and the amount of ink in one design portion will not be excessively large, making it difficult for print-through to occur.

[0031] The pattern according to the present invention is formed by halftone printing and solid printing. The ratio of the total area of ​​the pattern part is 8 to 20%. Preferably, it is 8 to 10%. The pattern part is the combined part of the halftone dot part and the solid part. The ratio of the total area refers to the ratio of the pattern part to the area of ​​one side of the toilet paper. In addition, since the pattern of the toilet paper on which the pattern is printed is repeated at a predetermined pitch due to the manufacturing process, the method of calculating the ratio of the total area of ​​the pattern part is to cut 10 sheets of the toilet paper at 50 cm each from the tip excluding the tail seal part as samples, calculate the ratio of the area of ​​the pattern part to the area of ​​one side of each sheet (width of the toilet paper x 50 cm), and use the average value of the 10 sheets. The area of ​​the pattern part in the sample may be measured by optically scanning the sample and measuring it using known software.

[0032] If the ratio of the total area of ​​the pattern portion is 8 to 20%, the toilet paper will not feel hard due to the application of ink during use, and the occurrence of wrinkles and twists during manufacturing, which is performed with the tension required for the roll configuration of the present invention, particularly the winding length and winding diameter, is prevented. Note that, although the halftone dot printing is microscopically composed of ink-applied parts and non-inked parts, the halftone dot portion in the present invention means the entire part that is actually recognized as one pattern by the halftone dot printing, including not only the ink-applied parts but also the non-inked parts. Note that the ratio of the halftone dot portion to the solid portion in one pattern is preferably 60:40 to 90:10, and more preferably 65:35 to 85:15.

[0033] The shape of each dot in the halftone dot printing according to the present invention is not particularly limited, and may be, for example, a rhombus, a square, a rectangle, a circle, an ellipse, a polygon, a star, or the like.

[0034] Furthermore, in the toilet paper according to the present invention, the ratio of the total area of ​​the dotted parts is 6.0% or more, and the ratio of the total area of ​​the solid parts is 4.0% or less. By making the ratio of the total area of ​​the dotted parts 6.0% or more and the ratio of the total area of ​​the solid parts 4.0% or less, it is possible to ensure design without excessively reducing the recognizability of the design, and ink is less likely to strike through the back when applied, and design is ensured. In addition, the toilet paper does not become hard as a whole, and wrinkles and twists are less likely to occur during the above-mentioned manufacturing process. Furthermore, when combined with other configurations according to the present invention to make a toilet roll, the solid parts are not excessively recognized through the non-patterned parts of the toilet paper located on the outer surface side, resulting in a toilet roll that is easily recognized as the intended design.

[0035] As with the total area of ​​the design, the percentage of the total area of ​​the dotted parts and the percentage of the total area of ​​the solid parts are calculated by cutting 10 sheets of toilet paper, each 50 cm long, from the tip excluding the tail seal, and calculating the percentage of the total area of ​​the dotted parts and the solid parts relative to the area of ​​one side of each sheet (toilet paper width x 50 cm), and averaging the percentage for the 10 sheets. The areas of the dotted parts and the solid parts in the sample can also be measured by optically scanning the sample and using known software.

[0036] In the present invention, the dot area ratio in the dot portion is 20 to 60%, and particularly preferably 30 to 50%. The dot area ratio is the ratio of the portion of the dot portion to which ink is actually applied. If the dot area ratio is less than 20%, the clarity of the design deteriorates, and if the dot area ratio exceeds 60%, the design approaches solid printing, the design does not have a light pattern due to dot printing, the design is deteriorated, and the design portion tends to become hard. In particular, when the ink is water-based, the paper shrinks due to moisture, and the paper is likely to wrinkle or twist when the total area ratio of the design according to the present invention is used.

[0037] The design on the toilet paper according to the present invention is preferably printed by flexographic printing (relief printing) using water-based ink. However, intaglio printing such as gravure printing, and planographic printing such as offset printing can also be used. In particular, if the water-based ink has a viscosity of 10 to 50 cps, a vehicle content of 30 to 60% by mass, and a moisture content of 70 to 40% by mass, the design can be made sufficiently clear, and wrinkles and twisting are unlikely to occur even if moisture penetrates the paper. The viscosity is a value measured using a B-type viscometer.

[0038] When printing the pattern according to the present invention, the ruling of the anilox roll used is not necessarily limited, regardless of whether it is a halftone dot portion or a solid portion, but it is preferable that it is 250 to 600 / 1 inch, more preferably 250 to 500 / 1 inch. It is suitable for forming the pattern according to the present invention.

[0039] The toilet roll according to the present invention is a toilet paper having the above-mentioned pattern, and has a winding density of 0.83 to 2.0. In 5 The toilet paper is wound around a paper tube with a length of 65 to 90 m. The toilet paper length of 65 to 90 m is more than twice as long as the conventional 2-ply, 25 m long toilet paper products for general households. The length is measured while the toilet roll is unwound without tension. For example, it may be measured while folding back the roll in a zigzag pattern every 5 m from the unwound state.

[0040] The toilet roll according to the present invention has the above-mentioned winding length and a winding density of 0.83 to 2.05. It is preferably 0.95 to 1.45, and particularly preferably 1.00 to 1.30. The winding density according to the present invention is a value calculated by actual cross-sectional area / theoretical cross-sectional area. The actual cross-sectional area is a value calculated by winding length x paper thickness. On the other hand, the theoretical cross-sectional area is a value calculated by (winding diameter / 2) x (winding diameter / 2) x π-(paper tube outer diameter / 2) x (paper tube outer diameter / 2) x π. In other words, it is an area obtained by subtracting the area of ​​the open end side of the paper tube from the area of ​​the end face. In the case of the above-mentioned winding length, those with a winding density in the range of 0.83 to 2.05 are particularly easy to manufacture and have very few wrinkles or twists. In addition, when the roll is held by hand at the circumferential surface, it feels moderately tight, and it feels that there is a firm winding length, and it is not excessively soft and does not feel hard. If it exceeds 2.05, the roll tends to feel harder than the actual wound length, whereas if it is less than 0.83, the roll tends to feel excessively soft for the wound length, making it difficult to feel firm.

[0041] The toilet roll according to the present invention has the above winding density and a roll density of 0.10 to 0.30 g / cm. 3 More preferably, it is 0.10 to 0.25 g / cm. 3 The roll density is expressed as (roll mass) ÷ (roll volume). The roll mass is the mass of toilet roll per 114 mm of roll width. The roll volume is expressed as [{cross-sectional area of ​​the roll winding diameter (diameter) L2 part} - (cross-sectional area of ​​the paper core outer shape L3 part)] x roll width (converted per 114 mm). The roll density also indicates how tightly and densely the toilet roll is wound, or how loosely and densely the toilet roll is wound. Volume If it is too loose, the area near the paper core will tend to deform excessively, such as popping out, and if it is too stiff, the toilet paper will feel stiff when you hold it in your hand.

[0042] In the toilet roll according to the present invention, the ratio of the total area of ​​the patterned parts is 8 to 20%, the ratio of the total area of ​​the dotted parts is 6.0% or more, and the ratio of the total area of ​​the solid parts is 4.0% or less, as described above, so that the pattern is fully recognizable, the print is unlikely to show through, and wrinkles and twists are extremely small. In other words, when the winding length is increased and the winding density is increased, it is necessary to wind the toilet paper around the paper core with increased tension when forming the toilet roll. In toilet paper having a pattern, the paper stretches differently between the printed parts to which ink is applied and the non-printed parts to which ink is applied, so that when the tension is increased, the toilet paper is likely to wrinkle or twist when it is made into a toilet roll, but the toilet roll according to the present invention solves such problems. In other words, a toilet roll is provided that has excellent pattern recognition, does not show through, feels sufficiently soft as a product when held in the hand, and does not wrinkle or twist.

[0043] Furthermore, the toilet roll according to the present invention preferably has a void ratio of 3 to 20%. The void ratio (%) according to the present invention is a value calculated by (actual void volume of the entire roll) / (theoretical roll volume)×100. The actual roll volume is calculated by dividing the actual cross-sectional area (cm 2 The actual void volume of the entire roll is calculated by (theoretical roll volume (cm)) × (roll width (cm)), and the theoretical roll volume is calculated by (roll length (cm)) × 2 × (paper thickness (1 ply, cm)) × (roll width (cm)). 3 ))-(actual roll volume (cm 3)). The roll width L1 may be about 100 to 130 mm. The void ratio is an index showing how much space exists in the toilet roll, and indicates the degree of spatial winding. This index is adjusted by the embossing, paper thickness, and winding hardness. When the paper thickness is thick, the void ratio is high, but this may be due to an embossing that is too deep and hard to crush, or the paper layer itself being thick, and in either case, it may feel hard. When the void ratio according to the present invention is high, the roll tends to feel hard, and when the void ratio is low, the roll tends to feel soft. Note that if the void ratio exceeds 20%, the back-bleed of the pattern may become noticeable, making it difficult to visually recognize the design of the roll, and if it is below 3%, the pattern may feel unclear due to print rubbing.

[0044] In addition, the toilet paper according to the present invention has a whiteness of 80% or more in the portion without a pattern print, and the color difference ΔE between the Lab value measured directly on the portion with a pattern print in the lower layer and the Lab value measured through the white portion without a pattern print in the upper layer toilet paper is ΔE=((ΔL 2 +(Δa) 2 +(Δb) 2 ) 1 / 2is preferably in the range of 2.20 or less. More preferably, it is less than 2.00. Furthermore, it is preferable that the color difference ΔE' between the Lab value measured through the white part of the upper toilet paper without pattern printing and the Lab value of the white part of the upper toilet paper without pattern printing is 6.0 or less. With such whiteness, ΔE and ΔE', as shown in FIG. 3, the pattern 40 of the lower layer seen through the white part of the upper toilet paper without pattern printing is not too clearly visible, but is dimly and faintly visible. At the same time, the pattern composed of the solid part 41 and the halftone dot part 42 of the upper layer, which are directly visible, is clearly visible. Therefore, the contrast between the patterns 41, 42 that are directly visible and the pattern 40 of the lower layer seen through the white part of the toilet paper provides a unique and distinctive design. In particular, when the pattern printing is between 8% and 20%, the pattern range is not excessively wide, and the effect of the contrast between the printed parts that are directly visible, the white parts, and the printed parts that are visible through the upper layer can be felt suitably.

[0045] 2, the procedure for measuring whiteness and color differences ΔE and ΔE' according to the present invention is to place five sheets of white cardboard 31 on a horizontal measurement table, place the sample 33 to be measured on top of them, and then place a non-patterned portion of toilet paper 34 taken from the same toilet roll as sample 33 on top of it so as to cover the pattern portion 32 to be measured on sample 33. Furthermore, a white cardboard 35 having a φ20 mm window cutout 36 is placed on top of it so that the pattern portion 32 to be measured is positioned within the window cutout 36.

[0046] Then, the whiteness and Lab value of the pattern to be measured (the Lab value of the above-mentioned pattern printed through the white part of the upper layer toilet paper without pattern printing) are measured by a spectroscopic whiteness and color difference meter through the toilet paper 34 from the window cutout part 36. Next, the toilet paper 34 overlapping the pattern part 32 is removed so that the measurement point does not move, and the whiteness and Lab value of the pattern part to be measured (the Lab value of the above-mentioned lower layer pattern printed part directly measured) are measured by a spectroscopic whiteness and color difference meter. Next, the sample is further removed, and the whiteness and Lab value of the top layer part of the five overlapping white boards 31 (the Lab value of the white part of the above-mentioned upper layer toilet paper without pattern printing) are measured by a spectroscopic whiteness and color difference meter (blank value). The spectroscopic whiteness and color difference meter is measured using a spectroscopic whiteness and color difference meter PF7000 manufactured by Nippon Denshoku Kogyo Co., Ltd. or an equivalent device. The color differences ΔE and ΔE' are calculated from each measured Lab value.

[0047] The number of colors constituting the pattern applied to the toilet paper according to the present invention is not limited, but from the viewpoint of cost and equipment, and because the toilet paper has a low density and is prone to bleeding, it is preferable to use 1 to 3 colors. Also, the solid part and the halftone dot part may have different colors. When measuring the Lab value of the above pattern, if one pattern has multiple colors, it is preferable to measure all of the different color parts and have all of the measured values ​​within the above numerical range.

[0048] The fibers in the toilet paper according to the present invention are not limited, but are preferably 70 to 100% by mass of virgin pulp and 0 to 30% by mass of recycled paper pulp. When recycled paper pulp is blended, it can be produced more cheaply than toilet paper made of 100% by mass of virgin pulp. In addition, recycled paper pulp tends to have finer fibers than the pulp fibers before recycling in the process of recycling pulp from recycled paper, and due to the nature of such fibers, the fibers tend to become denser and the paper strength is increased without increasing the paper thickness. On the other hand, if it is blended excessively, the texture such as flexibility is reduced. Therefore, in consideration of the characteristics of recycled paper pulp, the blending ratio may be determined to be in the range of 0 to 30% by mass. The type of recycled paper pulp is not necessarily limited, but recycled paper pulp made from milk carton recycled paper and high-quality recycled paper is particularly preferable. These contain a large amount of softwood kraft pulp (NBKP) derived from the raw material, so that they are easy to develop paper strength.

[0049] The pulp used is preferably softwood kraft pulp (NBKP) and hardwood kraft pulp (LBKP). The blend ratio of these is preferably 20:80 to 50:50 (NBKP:LBKP). NBKP may be derived from recycled milk carton paper. Note that toilet paper manufactured using a fiber material consisting of virgin pulp and the above-mentioned high-quality recycled paper pulp contains 5% by mass or less of mechanical pulp derived from recycled paper, 3% by mass or less of ash, and has a whiteness of about 80 to 85%.

[0050] In the toilet roll according to the present invention, the toilet paper has unevenness due to embossing. When the toilet paper is embossed, the toilet paper itself is soft, and the unevenness of the surface makes it excellent in wiping off feces. In addition, when the toilet paper is embossed, the unevenness of the paper surface makes it difficult to see the pattern of the lower layer through the paper surface, resulting in excellent design.

[0051] The toilet paper according to the present invention may be a single embossed toilet paper in which two plies are laminated together to give unevenness by embossing, or may be a double embossed toilet paper in which each ply is embossed to give unevenness and is laminated together to give two plies, preferably a double embossed toilet paper. The double embossed toilet paper is easier to achieve the winding density and winding hardness according to the present invention. Furthermore, among the double embossed toilet paper, it is preferable to use a two-ply double embossed toilet paper in which two sheets, one side of which has a recess and the other side of which has a protrusion formed by embossing, are laminated so that the recessed surface faces outward. Gaps are likely to form between the plies, making it more difficult to see the pattern of the lower layer through the paper surface, resulting in excellent design. In addition, in this double embossed toilet paper, the basis weight is particularly preferably 11.5 to 15.0 g / m 2 More preferably, the range is 11.5 to 14.0 g / m 2 It is.

[0052] The specific pattern of the unevenness by embossing is not necessarily limited. The embossing pattern can be an appropriate embossing pattern such as a micro embossing, a dot embossing, a design embossing, etc. However, it is desirable that the unevenness by embossing is arranged so as not to deteriorate the visibility of the printed pattern. For example, a pattern in which the recesses are simply arranged regularly so that the base material is perceived as unrelated to the pattern is desirable. As a more specific example, a pattern in which a square, a triangle, a polygon, a circle, an ellipse, a square star shape obtained by extending a square of a square, etc. are arranged regularly vertically and horizontally is desirable. Such a pattern can be one in which the design by the unevenness pattern by embossing and the design of the printed pattern do not interfere with each other, and a design by synergy is felt.

[0053] A particularly suitable pattern of the recesses (protrusions) by embossing is one in which, as shown in FIG. 4, the recesses 51 (FIG. 4A) are square with a bottom surface of diagonal L5×diagonal L5=1.0-1.5 mm×1.0-1.5 mm, or the recesses 51 are substantially square with the four corners of the square extending diagonally outward (FIG. 4B), are arranged in a lattice pattern with a center distance L6 of 4.5-5.5 mm and an arrangement angle of 45° with respect to the width direction, and between the recesses 51, there are valley lines 53 extending from the four corners of the recesses. It is preferable that the valley lines 53 are arranged in a gradually gradual arch shape in cross section so that the four corners of the recesses 51 are deepest and the middle between the recesses is shallowest. This embossing pattern does not reduce the design of the printed design, and is easy to provide excellent softness, flexibility, and ease of wiping off feces. In addition, the valley line portion 53 distributes the tension during winding toward 45° in the width direction, so that the unevenness caused by the embossing becomes extremely clear in the winding length of the toilet roll according to the present invention, and wrinkles and the like are less likely to occur.

[0054] Here, the preferred embossing density according to the present invention is 3 to 25 embossments / cm 2 , preferably 4 to 20 pieces / cm 2 3~25 pieces / cm 2 With an embossing density of 100%, the printed pattern is unlikely to give a cheap impression, and the improved design is likely to be felt, even if the ratio of the total area of ​​the pattern portion is less than 10% and the ratio of the total area of ​​the halftone dot portion is 6.0%, due to the synergy between the design of the embossed portion and the design of the printed pattern according to the present invention. The embossing density is measured using a one-shot 3D measuring macroscope VR-3200 or an equivalent device manufactured by Keyence Corporation, and image analysis software "VR-H2A" or an equivalent software. The measurement is performed under conditions of a magnification of 12 times and a visual field area of ​​24 mm x 18 mm. The area of ​​the range including the embossed group of multiple units that constitute the embossed pattern is measured, and the number of embossments in that range is counted. "Area including the embossed group of multiple units" means the smallest unit that can constitute the entire embossed pattern that divides the toilet paper plane into equal areas, or a closed section that is multiple times the smallest unit. Embossing density (pieces / cm2 The magnification and the area of ​​the field of view can be calculated as follows: Magnification=(number of embossments in the area including the group of embossments in units of multiple units)÷(area of ​​the area including the group of embossments in units of multiple units). However, the magnification and the area of ​​the field of view can be appropriately changed depending on the size of the embossments (recesses). EXAMPLES

[0055] Next, the examples and comparative examples of the toilet roll of the present invention were checked for "sheet smoothness," "roll surface smoothness," "anti-stripping," and "print clarity (absence of print rubbing)." The configuration of the toilet roll, the physical properties and composition of the toilet paper, and the test results of each example are shown in Table 1 below. In examples 4 and 5, single embossed toilet paper was rolled up. In other examples and comparative examples, 2-ply double embossed toilet paper was rolled up, in which two sheets, one side of which has a recess and the other side of which has a protrusion formed by embossing, are laminated so that the recessed surface faces outward. The embossing pattern in each example was the recessed arrangement shown in FIG. 4(B).

[0056] The smoothness of the sheet was evaluated by taking two pitches of toilet paper from the toilet roll, with the space between adjacent perforations being one pitch, and having the subjects actually touch the two pitches of toilet paper and give a score from 1 to 5 for the smoothness of the sheet surface. The evaluation criteria for smoothness were 5 for "satisfied," 4 for "somewhat satisfied," 3 for "neither satisfied nor dissatisfied," 2 for "somewhat dissatisfied," and 1 for "dissatisfied." The values ​​shown in Table 1 are the average values ​​rounded off to single digits. There were 30 subjects.

[0057] The smoothness of the roll surface was evaluated by having the subjects actually touch the outer periphery of the toilet roll and give a score from 1 to 5. The evaluation criteria for smoothness were 5 for "satisfied", 4 for "somewhat satisfied", 3 for "neither satisfied nor dissatisfied", 2 for "somewhat dissatisfied", and 1 for "dissatisfied". The values ​​shown in Table 1 are average values ​​rounded off to single digits. There were 30 subjects.

[0058] The prevention of print-through was evaluated by having subjects actually visually observe the reverse side (non-printed part) of the toilet roll that corresponds to the printed part on the outer circumference, and assigning a score to the bleeding of ink onto the reverse side (non-printed side) of the toilet paper, with "no print-through at all" being 5, "no print-through" being 4, "neither" being 3, "some print-through" being 2 and "some print-through" being 1. The values ​​shown in Table 1 are the average values ​​rounded off to single digits. There were 30 subjects.

[0059] The print clarity was evaluated by having subjects actually visually observe the printed portion on the outer surface of the toilet roll, and assigning a score according to the following criteria: "clear with no rubbing", 5; "slight rubbing, but generally clear", 4; "rubbing, but generally clear", 3; "some rubbing and slightly unclear", 2; and "overall rubbing and unclear printing". The values ​​in Table 1 are average values ​​rounded off to single digits. There were 30 subjects.

[0060] [Table 1]

[0061] In Examples 1 to 7, the paper is thin in order to make the sheets longer, but the halftone printing provides sufficient design with a total pattern area of ​​8% or more, while preventing bleed-through. In contrast, in Comparative Examples 1, 3, and 4, the total pattern area ratio is within the range of the present invention, but the patterns are all solid printed. In these cases, bleed-through has been confirmed.

[0062] In Comparative Example 2, the pattern is composed of halftone dots and solid areas, but the ratio of the total area of ​​the solid areas is higher than that of the present invention. Strike-through is also observed in Comparative Example 2.

[0063] On the other hand, Examples 5 and 6 are single embossed, and although they received higher overall evaluations than the Comparative Examples, they received slightly lower evaluations than the double embossed ones of Examples 1 to 4 and Example 7. The double embossed ones gave more desirable results.

[0064] In particular, in terms of print clarity, the results were good when the ten-point average roughness (RzJIS) was within the range of the present invention and the double embossing was used.

[0065] As described above, the toilet roll according to the present invention is easy to manufacture, has no wrinkles or kinks, has a highly aesthetically pleasing pattern, and has a smooth surface, even when made long. [Explanation of symbols]

[0066] 1...toilet roll, 10...toilet paper, 20...paper tube (core), L1...toilet roll width, L2...toilet roll roll diameter, L3...toilet roll core diameter (outer diameter of paper tube), 51...concave, 53...valley line, 40...pattern in lower layer, 41...solid part in upper layer, 42...dot part in upper layer.

Claims

1. A toilet roll having a roll diameter of 90 to 120 mm, the roll being made of two plies of toilet paper, A toilet paper having a paper thickness of 60 to 90 μm per ply, the paper having a pattern formed by halftone dot printing and solid printing printed on one side, the pattern portion having a ratio of a total area of ​​8 to 20%, the halftone dot portion having a ratio of a total area of ​​6.0% or more, and the solid portion having a ratio of a total area of ​​4.0% or less, the toilet paper being wound around a paper tube with a winding density of 0.83 to 2.05 and a winding length of 65 to 90 m, with the surface on which the pattern is printed being the outer layer, And the number of crepes is 35 to 50 per 10 mm. A toilet roll characterized by:

2. The toilet roll according to claim 1, wherein the ten-point average roughness [RzJIS] of the outer layer side of the toilet paper is 0.025 mm to 0.320 mm.

3. The toilet paper is a two-ply double embossed toilet paper in which two sheets, one of which has a concave portion on one side and a convex portion on the other side, are laminated together with the concave portions facing outward, as described in claim 1 or 2.

4. Roll density is 0.1 to 0.3 g / cm ３ The toilet roll according to claim 1 or 2.

5. The toilet roll according to any one of claims 1 to 4, wherein the void ratio is 3 to 20%.

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