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 because toilet space is limited, the length of the roll is an important factor in consumers' purchasing decisions.

[0003] The roll length of toilet paper rolls for popular household products has typically been around 25 m for two-ply (also known as double) and around 50 m for one-ply (also known as single), but in recent years, longer rolls 1.5 to 3 times longer have become popular (see Patent Document 1 below).

[0004] In order to make such long toilet rolls usable in commonly used household toilet paper holders, the toilet paper must have a low basis weight, be thin in thickness, and be tightly wound.

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

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-064664 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-188070 Summary of the Invention [Problem to be solved by the invention]

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

[0008]

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

[0010] Furthermore, because toilet rolls are made up of multiple layers of toilet paper stacked together, the pattern of the lower layer of toilet paper becomes too visible in long toilet rolls, 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 product that has a visually recognizable design and a surface that is easily perceived as smooth. [Means for solving the problem]

[0012] The first means for solving the above problem is: A toilet roll made of two-ply toilet paper rolled into a roll with a diameter of 90 to 120 mm, The sheet has two sheets, one of which has a recessed portion formed on one side by embossing and the other of which has a protruding portion formed on the other side, laminated together so that the recessed surface faces outward, and has a two-ply double embossed texture. A pattern is printed on the outer layer side of the toilet roll, and no printing is done on the back side, The void ratio is 3 to 20%, and the winding density is 0.83 to 2.05, and it is wound on a 65 to 90 m paper tube. The toilet paper has a ten-point average roughness [RzJIS] of the outer layer side of 0.025 mm or more and less than 0.035 mm, This toilet roll is characterized by the following:

[0013] The second method is The toilet roll according to the first aspect has a roll density of 0.1 to 0.3. [Effects of the Invention]

[0014] According to the present invention, a toilet roll is provided which is easy to manufacture, has no wrinkles or creases, has a visually recognizable design, and has a smooth surface, even though it is a long toilet roll. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view of a toilet roll according to an embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a schematic diagram for explaining the procedure for measuring whiteness and color difference according to the present invention. [Figure 3] FIG. 10 is a diagram for explaining the design printing according to the present invention. [Figure 4] 1A to 1C are diagrams illustrating examples of embossing patterns according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Next, the toilet roll according to the present invention will be described with reference to the drawings. As shown in Figure 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 in a roll shape.

[0017] 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 toilet rolls is specified in JIS P 4501 as 120 mm or less, and holders for holding general toilet rolls are manufactured based on this 120 mm standard. The toilet roll according to this embodiment has a roll diameter of 120 mm or less and can be set in a general holder. Here, the roll diameter L1 is a value measured using a diameter ruler manufactured by Muratec KDS Corporation or an equivalent device. The measured value is the average value of measurements taken at three different locations in the width direction. The roll width L1 of the toilet roll according to this 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 42 mm.

[0018] The toilet roll according to the present invention is characterized in that it has a textured surface due to embossing, and one side of which is printed with a pattern formed by halftone dot printing and solid printing, the proportion of the total area of ​​the pattern being 8 to 20%, the proportion of the total area of ​​the halftone dots being 6.0% or more, and the proportion of the total area of ​​the solid parts being 4.0% or less, and the toilet paper has a paper thickness of 60 to 90 μm per ply, and is wound around a paper tube of 65 to 90 m at a winding density of 0.83 to 2.05, with the surface on which the pattern is printed facing the outer layer.

[0019] By having these configurations, the toilet roll of the present invention is less likely to suffer from ink bleed-through when a pattern is printed, is less likely to cause unnecessary ink bleeding to the back side, and is less likely to break during production. It also has no wrinkles or creases, and the dot-printed areas, solid-printed areas, and the pattern of the underlying toilet paper are not overly visible, resulting in a distinctive design. Furthermore, the hard texture of the ink-applied areas is less noticeable, making it easier to feel smooth.

[0020] The toilet roll according to the present invention has a paper thickness of 60 to 90 μm per ply of wound toilet paper. Preferably, it is 60 to 85 μm. When the paper thickness of one ply is 60 to 90 μm, the toilet paper can be made strong and soft enough for toilet paper, and when a length of 65 to 90 m is wound around a paper core, the roll diameter L2 (diameter) can easily be set in the range of 90 to 120 mm. Furthermore, under the conditions for pattern printing according to the present invention, there is no ink bleed-through or unnecessary ink bleeding onto the back surface, and paper breaks during production are less likely to occur.

[0021] To measure paper thickness, the test piece is conditioned for at least 8 hours under the conditions specified in JIS P 8111 (1998), and then measured as a single ply using a PEACOCK G-type dial thickness gauge (thickness measuring device) (manufactured by Ozaki Seisakusho Co., Ltd.) under the same conditions. Specifically, after ensuring that there is no dirt or dust between the plunger and the measuring table, the plunger is lowered onto the measuring table, the dial thickness gauge's scale is moved to zero, the plunger is then raised, the sample is placed on the testing table, and the plunger is slowly lowered, and the gauge reading is taken. During measurement, the plunger is simply placed on the testing table; it is not pressed down. The plunger's metal terminal, a circular flat surface with a diameter of 10 mm, is placed perpendicular to the paper surface. The load during paper thickness measurement is approximately 70 gf. The paper thickness is calculated as the average value obtained by performing 10 measurements. Measurements are also performed in the same manner even if the toilet paper has embossed recesses and protrusions. In this case, measurements are performed so that each recess is entirely within the measuring table. The collapse of concave and convex parts can be ignored during measurement. The difference in paper thickness caused by the collapse of concave parts can be ignored during this paper thickness measurement.

[0022] 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, it is 12.0 to 15.0 g / m 2 12.5~16.0g / m 2 Within this range, it is easy to adjust the winding density and void ratio of the toilet roll according to the present invention. Furthermore, the dry tensile strength and wet tensile strength of the toilet roll according to the present invention may be adjusted appropriately by a known method within a range that does not impede the effects of the present invention.

[0023] 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. This ten-point mean roughness [RzJIS] range reduces print rubbing, improves print clarity, and facilitates excellent design. In particular, because print clarity is improved, design is less likely to deteriorate even when the total area of ​​the design is 8 to 9.5% and the total area of ​​the dots is 6.0 to 7.0%, a small range of ink application. The ten-point mean roughness [RzJIS] is measured using a Keyence Corporation One-Shot 3D Measuring Macroscope VR-3200 or equivalent and image analysis software "VR-H2A" or equivalent software. Measurements are performed at a magnification of 12x and a field of view of 24mm x 18mm. However, the magnification and field of view can be adjusted depending on the size of the embossing (depressions). Ten-point average roughness (RzJIS) is measured by capturing a 3D image and analyzing the data at a location that avoids the inked pattern area, at any location if there is no embossing, or at a location that avoids the depressions if there are embossed depressions, especially at the midpoint between adjacent depressions if the depressions are regularly arranged. 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." The measurement location on the outermost surface of the toilet roll reflects the surface smoothness of the toilet roll, but accuracy decreases at the beginning of use. Therefore, the measurement location should be anywhere within 29-31% of the outermost edge. The measurement value is the average of 10 points, and the measurement sample can be fixed to the measurement table in a manner that does not affect the measurement value.

[0024] Furthermore, the toilet paper of the present invention preferably has a crepe count of 35 to 50 crepes per 10 mm. The crepe count is 35 to 50 crepes per 10 mm, preferably 37 to 48 crepes per 10 mm, and more preferably 39 to 45 crepes per 10 mm. This crepe count enhances the perceived smoothness of the surface, particularly in the case of the above-described pattern printing of the present invention, making the hard texture of the ink-applied areas less noticeable and enhancing the overall perceived smoothness. The crepe count can be adjusted by the crepe ratio during base paper production, the presence or absence of calendering, and the calendering pressure. The crepe count is measured using a Keyence Corporation One-Shot 3D Measuring Macroscope VR-3200 or equivalent, and image analysis software "VR-H2A" or equivalent software. Measurements are performed at a magnification of 12x and a field of view of 24mm x 18mm. The magnification and field of view can be adjusted depending on the size of the embossments (recesses). The crepe count is measured by capturing a 3D image and analyzing the data, avoiding the inked pattern area and any position if the surface is not embossed. If there are embossed depressions, avoid the depressions. For regularly spaced depressions, particularly those between adjacent depressions, a 3D image is taken and analyzed. The profile line to be measured in the line roughness measurement is specified to be perpendicular to the paper flow direction, and measurements and analysis are performed. The measurement parameter used is "line roughness." The number of peaks on the resulting cross-sectional curve measured over a 10-mm measurement distance is counted as the crepe count. The outermost surface of the toilet roll reflects the surface smoothness of the toilet roll, but accuracy decreases at this point. Therefore, the measurement location should be anywhere between 29% and 31% from the outermost edge at the start of use. The measurement value is the average of 10 points, and the sample can be fixed to the measurement table in a manner that does not affect the measurement value.

[0025] The toilet roll of the present invention has a pattern printed on one side of the toilet paper, and is wound around a paper tube with the side with the printed pattern facing outward. In other words, the toilet roll of the present invention has a pattern only on the side facing outward. By printing the pattern on the outward side, the pattern can be seen directly from the outside, and is particularly easy to see even if the pattern is printed faintly, such as with halftone dot printing.

[0026] Furthermore, because toilet rolls are made up of multiple layers of toilet paper, if the pattern of one layer or more is visible through the paper, there is a risk that the pattern on the lower layer will be mixed with the pattern on the outer surface. However, since the toilet paper of the present invention is particularly two-ply, there is an unprinted layer interposed between the inner ply. Therefore, if the pattern is formed only on the outer layer within the paper thickness range specified in the present invention, the pattern on the outer surface will be fully visible, while the pattern on the lower layer will be difficult to see. This is even more true if the basis weight is as described above. To have a pattern only on the outer layer side, the paper can be wound with the printed side facing outward.

[0027] The patterns of the present invention are formed by printing, and do not include those colored at the papermaking stage by adding 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 from the following: plants such as flowers, trees, and grass; living creatures 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 it can be 102 mm 2 ~918mm 2 If the ink amount is within this range, the pattern is easy to see and is perceived as having excellent design, and the amount of ink in one pattern portion is not excessively large, making it less likely for print-through to occur.

[0028] The pattern according to the present invention is formed by halftone dot printing and solid printing. The proportion of the total area of ​​the pattern portion is 8 to 20%, preferably 8 to 10%. This pattern portion is the combined area of ​​the halftone dot portion and the solid portion. The proportion of the total area refers to the proportion of the pattern portion to the area of ​​one side of the toilet paper. Note that in toilet paper with a printed pattern, the pattern is repeated at a predetermined interval due to the manufacturing process, so the method for calculating the proportion of the total area of ​​the pattern portion is to cut 10 sheets of toilet paper, each 50 cm long, from the tip, excluding the tail seal, to use as samples, calculate the proportion of the area of ​​the pattern portion to the area of ​​one side of each sheet (toilet paper width x 50 cm), and use the average value of these 10 sheets. The area of ​​the pattern portion in the sample can be measured by optically scanning the sample and measuring using known software.

[0029] If the proportion of the total area of ​​the pattern portion is 8 to 20%, the toilet paper will not feel stiff due to the application of ink during use, and the occurrence of wrinkles and kinks during manufacturing, particularly when the tension required for the roll configuration of the present invention, such as winding length and winding diameter, is prevented. Microscopically, dot printing is composed of inked and non-inked areas, but the dot portion in this invention refers to the entire area that is actually recognized as a single pattern through dot printing, including not only the inked areas but also the non-inked areas. The ratio of dotted areas to solid areas in a single pattern is preferably 60:40 to 90:10, and particularly preferably 65:35 to 85:15.

[0030] 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 diamond, square, rectangle, circle, ellipse, polygon, star, or the like.

[0031] Furthermore, the toilet paper according to the present invention has a dotted area ratio of 6.0% or more and a solid area ratio of 4.0% or less. By setting the dotted area ratio to 6.0% or more and the solid area ratio to 4.0% or less, printability is reduced without significantly reducing the visibility of the design, ensuring design integrity. Furthermore, the toilet paper does not become stiff overall, making it less likely to wrinkle or crease during manufacturing. Furthermore, when combined with other configurations according to the present invention to produce a toilet roll, the solid area is not overly visible through the non-patterned areas of the toilet paper located on the outer surface, resulting in a toilet roll that is easily recognizable as the intended design.

[0032] The percentage of the total area of ​​the dotted areas and the percentage of the total area of ​​the solid areas are calculated in the same way as the percentage of the total area of ​​the design areas 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 areas and the solid areas relative to the area of ​​one side of each sheet (toilet paper width x 50 cm), and using this as the average value for the 10 sheets. The areas of the dotted areas and solid areas in the sample can also be measured by optically scanning the sample and using known software.

[0033] In the present invention, the dot area ratio in the halftone dot portion is 20 to 60%, and particularly preferably 30 to 50%. The dot area ratio is the percentage of the halftone dot portion that is actually inked. If the dot area ratio is less than 20%, the clarity of the design deteriorates. If the dot area ratio is more than 60%, the design approaches solid printing, the lightness of the design achieved by halftone dot printing is lost, the design quality deteriorates, and the design portion tends to become hard. Furthermore, particularly when using water-based ink, moisture causes the paper to shrink, making the paper more susceptible to wrinkling and creasing at the total area ratio of the design according to the present invention.

[0034] The design on the toilet paper of 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 water content of 70 to 40% by mass, the design can be sufficiently clear and wrinkles and creases are less likely to occur even if water penetrates the paper. The viscosity is measured using a B-type viscometer.

[0035] When printing the design according to the present invention, the ruling of the anilox roll to be used is not necessarily limited, regardless of whether it is a halftone dot portion or a solid portion, but it is desirable that it be 250 to 600 / inch, more preferably 250 to 500 / inch. This is suitable for forming the design according to the present invention.

[0036] The toilet roll according to the present invention has a winding density of 0.83 to 2.05 m / cm 2 The toilet paper is wound onto a paper tube of 65 to 90 meters in length. The 65 to 90 meter roll length of toilet paper is more than twice as long as the conventional 2-ply toilet paper for general household use, which is around 25 meters long. The roll length is measured while unwinding the toilet roll without applying tension. For example, it can be measured while folding back the roll in a zigzag pattern every 5 meters after unwinding.

[0037] The toilet roll according to the present invention has the above-mentioned winding length and a winding density of 0.83 to 2.05 m / cm. 2 Preferably, it is 0.95 to 1.45 m / cm 2 and particularly preferably 1.00 to 1.30 m / cm 2The winding density according to the present invention is a value calculated by multiplying the actual cross-sectional area by the theoretical cross-sectional area. The actual cross-sectional area is a value calculated by multiplying the winding length by the 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 the 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 winding length, in particular, when the winding density is 0.83 to 2.05 m / cm 2 The roll in this range is easy to manufacture and has very little wrinkles or twists. When the roll is held in the hand, it feels moderately tight and has a firm winding length, and is not excessively soft or hard. 2 If it exceeds 0.83m / cm, it will tend to feel stiffer than the actual winding length. 2 If it is less than this, the roll will feel excessively soft for the wound length, and it will be difficult to feel firm.

[0038] 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 It is more preferable that the density is 0.10 to 0.25 g / cm. 3 Roll density is expressed as (roll mass) ÷ (roll volume). Roll mass is the mass of toilet roll per 114 mm of roll width. Roll volume is expressed as [{cross-sectional area of ​​the roll's winding diameter (diameter) L1} - (cross-sectional area of ​​the paper core's outer diameter L3)] x roll width (converted to per 114 mm). Roll density is also an indicator of how tightly or loosely wound the toilet roll is. If it is too loose, the area near the paper core will be prone to excessive deformation, such as protruding, and if it is too stiff, the toilet roll will feel stiff when held in the hand.

[0039] In the toilet roll of the present invention, the proportion of the total area of ​​the patterned portions is 8 to 20%, the proportion of the total area of ​​the dotted portions is 6.0% or more, and the proportion of the total area of ​​the solid portions is 4.0% or less, as described above. This allows the pattern to be fully recognizable, is less likely to show through, and is extremely free of wrinkles and creases. In other words, when the winding length is increased and the winding density is increased, the toilet paper needs to be wound around the paper core with increased tension to form the toilet roll. In toilet paper with a pattern, the printed portions where ink is applied and the non-printed portions where ink is applied have different elongation rates, so increasing the tension can easily cause the toilet paper to wrinkle or crease when made into a toilet roll. However, the toilet roll of the present invention solves these problems. In other words, a toilet roll is provided that has excellent pattern recognizability, does not show through, feels sufficiently soft when held in the hand, and is free of wrinkles and creases.

[0040] 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 the value (actual void ratio of the entire roll) calculated by (actual void volume of the entire roll) / (theoretical roll volume)×100. The actual void volume of the entire roll is calculated by dividing the actual cross-sectional area (cm 2 The theoretical roll volume is calculated by (roll length (cm) x 2 x paper thickness (1 ply, cm)) x (roll width (cm)). The porosity (actual porosity of the entire roll, %) is calculated by (theoretical roll volume (cm) 3 ))-(actual roll volume (cm 3 ))) / (Theoretical roll volume (cm 3)) × 100(%). The roll width L1 may be approximately 100 to 130 mm. The void ratio is an index showing how much space exists within the toilet roll and indicates the degree of spatial tightening of the roll. This index is adjusted according to the embossing, paper thickness, and winding hardness. The void ratio increases when the paper thickness is thick, but this can occur when the embossing is excessively deep and hard to crush, or when the paper layer itself is thick. In either case, the roll may feel hard. When the void ratio according to the present invention is high, the roll tends to feel hard, while when the void ratio is low, the roll tends to feel soft. Note that if the void ratio exceeds 20%, the print may show through significantly, making the roll design difficult to see, and if it is below 3%, the print may feel unclear due to print rubbing.

[0041] Furthermore, the toilet paper according to the present invention has a whiteness of 80% or more in the area without a pattern print, and the color difference ΔE between the Lab value measured directly on the lower layer of the pattern print and the Lab value measured through the white area without a pattern print on the upper layer of the toilet paper is ΔE=((ΔL) 2 +(Δa) 2 +(Δb) 2 ) 1 / 2It is desirable that the whiteness (ΔE) is in the range of 2.20 or less. More preferably, it is less than 2.00. Furthermore, it is desirable that the color difference ΔE' between the Lab value measured through the white portion of the upper toilet paper layer without a pattern print and the Lab value of the white portion of the upper toilet paper layer without a pattern print is 6.0 or less. With such whiteness, ΔE, and ΔE', as shown in Figure 3, the pattern 40 of the lower layer, which can be seen through the white portion of the upper toilet paper layer without a pattern print, is not overly clearly visible, but rather appears dim and faint. At the same time, the pattern composed of the solid portion 41 and the halftone portion 42 of the upper layer, which can be seen directly, becomes clearly visible. Therefore, the contrast between the directly visible patterns 41 and 42 and the lower layer pattern 40, which can be seen through the white portion of the toilet paper, creates a unique and distinctive design. In particular, when the pattern printing is 8 to 20%, the pattern range is not excessively wide, and the effect of the contrast between the printed area that can be seen directly, the white area, and the printed area that can be seen through the upper layer can be felt favorably.

[0042] 2, the procedure for measuring whiteness and color differences ΔE and ΔE' according to the present invention is as follows: five sheets of white cardboard 31 are placed on a horizontal measurement table, and the sample 33 to be measured is placed on top of them. Furthermore, a portion of toilet paper 34 with no design taken from the same toilet roll as sample 33 is placed on top of it so as to cover the design 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 design portion 32 to be measured is positioned within the window cutout 36.

[0043] The whiteness and Lab value of the pattern to be measured (the Lab value measured through the unprinted white portion of the upper layer of toilet paper) are then measured using a spectrophotometer through the window cutout 36 and the toilet paper 34. Next, the toilet paper 34 that was placed on the sample 32 is removed so as not to move the measurement point, and the whiteness and Lab value of the pattern to be measured (the Lab value measured directly on the unprinted white portion of the upper layer of toilet paper) are measured using the spectrophotometer. Next, the sample is removed again, and the whiteness and Lab value of the top layer of the five stacked white cardboard sheets 31 (the Lab value of the unprinted white portion of the upper layer of toilet paper) are measured using the spectrophotometer (blank value). The spectrophotometer is a spectrophotometer / colorimeter PF7000 manufactured by Nippon Denshoku Industries Co., Ltd. or an equivalent. The color differences ΔE and ΔE' are calculated from the measured Lab values.

[0044] There is no limit to the number of colors that make up the pattern imparted to the toilet paper of the present invention, but from the viewpoints of cost and equipment, and because the toilet paper is low-density and prone to bleeding, it is desirable to use 1 to 3 colors. Also, the solid and dotted areas may be different colors. When measuring the Lab values ​​of the above-mentioned pattern, if a single pattern contains multiple colors, it is desirable to measure all of the different colored areas, and all of the measured values ​​should be within the above-mentioned numerical range.

[0045] The fibers in the toilet paper of the present invention are not limited, but preferably comprise 70 to 100% by mass of virgin pulp and 0 to 30% by mass of recycled paper pulp. Blending recycled paper pulp allows for more cost-effective production compared to toilet paper made from 100% by mass of virgin pulp. Furthermore, recycled paper pulp tends to have finer fibers than the pulp fibers before recycling during the process of recycling recycled paper. Due to this fiber property, the fibers tend to become denser and the paper strength increases without increasing the paper thickness. On the other hand, excessive blending reduces the texture, such as flexibility. Therefore, taking into account the characteristics of recycled paper pulp, the blending ratio should be set within the range of 0 to 30% by mass. While the type of recycled paper pulp is not necessarily limited, recycled paper pulp made from recycled milk carton paper and high-quality recycled paper is particularly desirable. These pulps are easily strengthened because they contain a large amount of softwood kraft pulp (NBKP) derived from the raw material.

[0046] 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. Toilet paper manufactured using a fiber material consisting of virgin pulp and the above-mentioned high-quality recycled paper pulp contains no more than 5% by mass of recycled mechanical pulp, no more than 3% by mass of ash, and has a brightness of approximately 80 to 85%.

[0047] In the toilet roll according to the present invention, the toilet paper has unevenness due to embossing. When toilet paper is embossed, the toilet paper itself is soft, and the unevenness on the surface makes it excellent at wiping away feces. Furthermore, when toilet paper is embossed, the unevenness on the paper surface makes it difficult to see the pattern of the underlying layer through the paper surface, resulting in excellent design.

[0048] The toilet paper according to the present invention may be single-embossed toilet paper in which two plies are laminated together to form concaves and convexes by embossing, or double-embossed toilet paper in which each ply is embossed to form concaves and convexes and then laminated together to form two plies, preferably double-embossed toilet paper. Double-embossed toilet paper is more likely to achieve the winding density and winding hardness according to the present invention. Furthermore, among double-embossed toilet paper, it is preferable to use a two-ply double-embossed toilet paper in which two sheets are embossed to form concaves on one side and convexities on the other side, and the concave-formed surfaces are laminated on the outside. Gaps are likely to form between the plies, making it more difficult to see the pattern of the underlying layer through the paper surface, resulting in excellent design. In this double embossed toilet paper, the basis weight is particularly preferably 11.5 to 15.0 g / m 2 It is more preferable to set the range to 11.5 to 14.0 g / m. 2 is.

[0049] The specific pattern of the recesses and protrusions created by embossing is not necessarily limited. The embossing pattern can be any appropriate embossing pattern, such as microembossing, dot-type embossing, or design embossing. However, it is desirable that the recesses and protrusions created by the embossing are arranged so as not to impair the visibility of the printed design. For example, a pattern in which recesses are simply arranged in a regular pattern so that the surface is perceived as a base unrelated to the design is desirable. More specific examples include squares, triangles, polygons, circles, ellipses, and square stars formed by extending the corners of a square, arranged regularly both vertically and horizontally. Such patterns can be designed so that the design of the recesses and protrusions created by embossing and the design of the printed design do not interfere with each other, and a synergistic design effect can be felt.

[0050] A particularly suitable pattern of embossed depressions (protrusions) is shown in Figure 4, in which depressions 41 (Figure 4A) are squares with a base measuring diagonal L5 x diagonal L5 = 1.0-1.5 x 1.0-1.5 mm, or depressions 51 are approximately squares with the four corners of the squares extending diagonally outward (Figure 4B), arranged in a grid pattern with a center-to-center spacing L6 of 4.5-5.5 mm and an angle of 45° with respect to the width direction, and between the depressions 51 are valley lines 53 extending from the four corners of the depressions. It is desirable that the valley lines 53 are arranged in a gradually curved cross section so that the four corners of the depressions 51 are deepest and the middles between the depressions are shallowest. This embossed pattern does not detract from the design of the printed design and is likely to provide excellent softness, flexibility, and ease of wiping. In addition, the valley line portion 53 distributes tension during winding toward a 45° angle in the width direction, making the unevenness caused by the embossing extremely clear in the winding length of the toilet roll of the present invention, and making it less likely for wrinkles to occur.

[0051] 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 to 25 pieces / cm 2 With an embossing density of 1000, the printed pattern is less likely to give a cheap impression, and the improved design is more likely to be perceived, even if the proportion of the total area of ​​the patterned portion is less than 10% and the proportion of the total area of ​​the halftone dots 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 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 12x magnification and a field of view area of ​​24mm x 18mm. The area of ​​the range including the group of embossed portions each consisting of multiple units that make up the embossed pattern is measured, and the number of embossed portions in that range is counted. "Area including the group of embossed portions each consisting of multiple units" means the smallest unit that can constitute the entire embossed pattern, dividing the surface of the toilet paper into equal areas, or a closed section multiple times the smallest unit. Embossing density (pieces / mm2 ) = (number of embossments in an area including a group of embossments in units of multiple units) ÷ (area of ​​an area including a group of embossments in units of multiple units). However, the magnification and field area can be changed as appropriate depending on the size of the embossments (recesses). [Example]

[0052] Next, the examples and comparative examples of the toilet rolls of the present invention were checked for "sheet smoothness," "roll surface smoothness," "anti-bleed-through," and "print clarity (absence of print rubbing)." The toilet roll configuration, physical properties and composition of the toilet paper, and test results for each example are shown in Table 1 below. Examples 4 and 5 were rolled up with single-embossed toilet paper. Other examples and comparative examples were rolled up with two-ply double-embossed toilet paper, in which two sheets, each embossed to form recesses on one side and protrusions on the other, were laminated with the recessed surfaces facing outward. The embossing pattern in each example was the recessed arrangement shown in Figure 4(B).

[0053] 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 those two pitches of toilet paper and rate the smoothness of the sheet surface on a scale of 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 to single digits. There were 30 subjects.

[0054] The smoothness of the roll surface was evaluated by having the subjects actually touch the outer surface of the toilet roll and score it on a scale of 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 to single digits. There were 30 subjects.

[0055] The resistance to bleed-through was evaluated by having subjects visually observe the reverse side (non-printed area) of the toilet roll corresponding to the printed area on the outer periphery, and assigning a score to the bleeding of ink onto the reverse side (non-printed side) of the toilet paper using an evaluation scale where 5 is "no bleed-through at all," 4 is "no bleed-through," 3 is "neither," 2 is "some bleed-through," and 1 is "some bleed-through." The values ​​shown in Table 1 are average values ​​rounded to single digits. There were 30 subjects.

[0056] The print clarity was evaluated by having test subjects visually observe the printed area on the outer surface of the toilet roll and assigning a score based on the following criteria: 5 for "clear with no rubbing," 4 for "slight rubbing but generally clear," 3 for "some rubbing but generally clear," 2 for "some rubbing and slightly unclear," and 1 for "complete rubbing and unclear print." The values ​​shown in Table 1 are average values ​​rounded to single digits. There were 30 test subjects.

[0057] [Table 1]

[0058] In Examples 1 to 7, the paper is thin to accommodate longer lengths, but the halftone dot printing provides sufficient design with a total design area of ​​8% or more, while preventing bleed-through. In contrast, in Comparative Examples 1, 3, and 4, the total design area percentage is within the range of the present invention, but the design is entirely solid printed. In these cases, bleed-through was confirmed.

[0059] In Comparative Example 2, the design is composed of halftone dots and solid areas, but the proportion of the total area of ​​the solid areas is higher than in the present invention. Strike-through was also observed in Comparative Example 2.

[0060] On the other hand, Examples 5 and 6 were single embossed and received higher overall ratings than the comparative examples, but slightly lower ratings than the double embossed examples of Examples 1 to 4 and 7. Double embossing gave more desirable results.

[0061] In particular, when examining print clarity, good results were obtained when the ten-point average roughness (RzJIS) was within the range of the present invention and the double embossing was used.

[0062] As described above, the toilet roll according to the present invention is easy to manufacture, has no wrinkles or creases, has a visually recognizable design, and has a smooth surface even when made long. [Explanation of symbols]

[0063] 1...toilet roll, 10...toilet paper, 20...paper tube (core), L1...toilet roll roll diameter, L2...toilet roll core diameter, L3...toilet roll width, 51...recess, 53...valley line, 40...lower layer pattern, 41...solid area of ​​upper layer, 42...dot area of ​​upper layer.

Claims

1. A toilet roll having a roll diameter of 90 to 120 mm, which is made by rolling two plies of toilet paper, A toilet paper having a paper thickness of 60 to 90 μm per ply, which has a textured surface due to embossing, one side of which is printed with a pattern formed by halftone dot printing and solid printing, the proportion of the total area of ​​the pattern portion being 8 to 20%, the proportion of the total area of ​​the halftone dot portions being 6.0% or more, and the proportion of the total area of ​​the solid portions being 4.0% or less, is 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 facing 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 according to claim 1 or 2 is a two-ply double-embossed toilet paper in which two sheets, each having a concave portion on one side and a convex portion on the other side formed by embossing, are laminated together with the concave surface facing outwards.

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 porosity is 3 to 20%.

Images