Hygienic paper tissue

Abstract

Provided is a sanitary paper that balances skin touch-related qualities such as softness and fluffiness with functional qualities such as toughness and water absorbency required for use on a bidet toilet, and does not easily cause dissatisfaction whether used in a regular scenario or on a toilet with a washing function. This is achieved by a sanitary paper in which two sheets are stacked to form a double-layered toilet paper, and the double-layered toilet paper is wound on a paper tube with a roll length of 20 m to 40 m and a roll diameter of 110 mm to 130 mm, characterized in that, in the toilet paper, the sheets, which have a recess on one side and a protrusion corresponding to the recess on the other side, are stacked with the protrusion-forming surfaces of the sheets facing each other, and the top of the protrusion is bonded with an adhesive; and the value of TS750 measured by a paper softness measuring device TSA is 20 dBV 2 rms to 35 dBV 2 rms, the value of TS7 is 7.0 BV 2 rms to 10.0 BV 2 rms, the value of D is 3.5 mm / N to 4.0 mm / N.

Description

Technical Field

[0001] This invention relates to a toilet paper roll made by winding strips of toilet paper into a roll. Background Technology

[0002] In the toilet paper industry, due to the diversification of consumer preferences, development work is ongoing to create product groups that cater to various tastes. For example, there are product groups such as: those called standard or regular products, which consist of double-ply toilet paper wound to a length of approximately 25 to 30 meters; those called long-size products, which have a winding length three times that of regular products, reaching approximately 75 to 90 meters; and those called products for smart toilets, which have a winding length similar to regular products, but with specially enhanced wet strength and absorbency.

[0003] Regular-sized products use the traditional winding length. Compared to longer-sized products, they have a relatively higher weight per unit area and greater paper thickness, making them a high-quality product category in recent years. They are favored by consumers who value qualities such as skin-friendly texture, softness, and fluffiness. Longer-sized products, on the other hand, are popular with consumers who prioritize the advantage of less frequent purchases / replacements. Smart toilet products are highly sought after by consumers who value the ability to easily clean the defecation and urination areas with warm or hot water, wipe away moisture left on the skin after washing, and experience a smooth and reassuring feel when handling feces and urine.

[0004] Products used in smart toilets improve wet strength, paper layer thickness, and strength by using temporary wet strength agents such as wet strength agents or cationic aldehyde-modified polyacrylamide copolymers, or by using lamination and embossing technology that involves bonding embossed layers with adhesives. This, in turn, improves the retention of interlayer voids.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 08-56868

[0008] Patent Document 2: Japanese Patent Application Publication No. 2006-320688

[0009] Patent Document 3: Japanese Patent Application Publication No. 2011-153387 Summary of the Invention

[0010] The technical problem that the invention aims to solve

[0011] However, in order to achieve a sense of strength, the paper used in smart toilets is made more rigid, which may result in a stiff feeling due to adhesives, or poor hydrolysis due to the high concentration of wet-strength agents. Therefore, it is inferior to conventional toilet paper in terms of softness, fluffiness, and hydrolysis. These factors may cause dissatisfaction among consumers who prefer smart toilets.

[0012] On the other hand, the applicant's investigation found that with the popularization of toilets with washing functions, toilets with washing functions are gradually entering thousands of households. Therefore, some consumers who choose regular products because they value softness and fluffiness feel feel that when using regular products on toilets with washing functions, their absorbency and paper strength are insufficient.

[0013] Therefore, the main objective of this invention is to provide a toilet paper roll that combines the softness, fluffiness, and other skin-touch qualities of conventional toilet paper with the strength, absorbency, and other functional properties of toilet paper used in smart toilets, ensuring that it is less likely to cause dissatisfaction whether used in regular settings or on a toilet with a washing function.

[0014] Technical means for solving problems

[0015] The first means to solve the above problems is

[0016] A type of toilet paper roll, comprising two layers of paper stacked together, is wound onto a paper tube with a roll length of 20 m to 40 m and a roll diameter of 110 mm to 130 mm, characterized in that... In the aforementioned toilet paper, paper layers with concave portions on one side and convex portions corresponding to the concave portions on the other side are stacked with their convex surfaces facing each other, and are bonded together on top of the convex portions using an adhesive; and The TS750 value measured by the TSA paper softness tester is 20 dBV. 2 rms~35 dBV 2 The values ​​for rms and TS7 are 7.0 dBV. 2 rms~10.0 dBV 2 The values ​​of rms and D are 3.5 mm / N to 4.0 mm / N.

[0017] The second approach to solving the above problem is

[0018] The toilet paper of the first method described above, wherein the longitudinal drying tensile strength of the toilet paper is 250 cN / 25 mm or more and 360 cN / 25 mm or less, and the transverse drying tensile strength is 65 cN / 25 mm or more and 120 cN / 25 mm or less; and

[0019] The ratio of its longitudinal dry tensile strength to its transverse dry tensile strength, i.e., longitudinal dry tensile strength / transverse dry tensile strength, is 2.9 or higher and 3.8 or lower.

[0020] The third approach to solving the above problems is

[0021] The toilet paper roll produced by the first or second method described above, wherein four sheets of the aforementioned toilet paper are overlapped and pressed into the testing terminal by a compression tester, exhibits a strength of 0.5 gf / cm³. 2 Position under load: T0 to 50 gf / cm 2 The displacement (T0-Tm) between positions Tm under load is called extensibility, which is 1.0 mm or more.

[0022] The fourth method to solve the above problems is

[0023] The toilet paper produced by the first to third methods described above, wherein the ratio of the transverse wet tensile strength to the transverse dry tensile strength of the toilet paper, i.e., transverse wet tensile strength / transverse dry tensile strength, is 0.20 to 0.40.

[0024] Other methods that solved the above problems are

[0025] The toilet paper rolls made by the first to fourth and other means described above are stacked in a nested form in which the convex portion of one paper layer is located in the non-convex portion of another paper layer, and the two paper layers are bonded together by applying an adhesive to the convex portion of the paper layer located on the outer surface side of the roll.

[0026] Invention Effects

[0027] According to the present invention, a toilet paper roll is provided that combines the softness, fluffiness and other skin-touch qualities of conventional toilet paper with the strength, absorbency and other functional properties of toilet paper used in smart toilets. It is unlikely to cause dissatisfaction whether used in regular scenarios or on toilets with a washing function. Attached Figure Description

[0028] Figure 1 This is a perspective view of a toilet paper roll according to an embodiment of the present invention.

[0029] Figure 2 This is a cross-sectional schematic diagram of toilet paper according to an embodiment of the present invention.

[0030] Figure 3 This is a top view of an example of toilet paper according to an embodiment of the present invention.

[0031] Figure 4 This is a schematic diagram illustrating the method for measuring the paper layer stretchability of the present invention.

[0032] Figure 5 This is a schematic diagram illustrating the method for measuring MMD according to the present invention.

[0033] Figure 6 This is a schematic diagram illustrating the method for measuring the roll tightness of the present invention.

[0034] Figure 7 This is a schematic diagram illustrating the steps for measuring the roll hardness of the paper roll according to the present invention.

[0035] Figure 8 This is a schematic diagram illustrating the steps for measuring the softness of the roll paper according to the present invention. Detailed Implementation

[0036] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0037] like Figure 1 As shown, the toilet paper roll of this embodiment is a double-layered hydrolyzable toilet paper 10, which is formed by stacking two paper layers, a first paper layer 11 and a second paper layer 12, and is wound around a paper tube (also called a core) 20, and is cylindrical in shape. In the toilet paper roll 1 of this embodiment, the toilet paper is wound with the first paper layer 11 as the outer surface side and the second paper layer 12 as the inner surface side.

[0038] In toilet paper rolls, the roll length of double-layered products known as regular products is about 25 m to 30 m, while the roll length of toilet paper roll 1 in this embodiment is 20 m to 40 m, preferably 20 m to 30 m, which is the same as that of products known as regular products.

[0039] The roll diameter L2 of the toilet paper roll 1 in this embodiment is 110 mm to 130 mm, preferably 110 mm to 120 mm. The holder for holding the toilet paper roll is generally manufactured based on JIS P 4501 with 120 mm as a reference. Since the roll diameter of the toilet paper roll in this embodiment is 110 mm to 130 mm or less, it can be placed on a general holder. Furthermore, if it is set to less than 110 mm due to its length, the toilet paper will be tightly wound, which can easily reduce its quality, such as its feel against the skin. Here, the roll diameter L2 is a value measured using a diameter gauge manufactured by MURATEC-KDS Co., Ltd. or a similar device. It should be noted that the roll width L1 of the toilet paper roll 1 in this embodiment is not limited, but is expected to be 100 mm to 120 mm. Additionally, the outer diameter L3 of the paper tube 20 is not limited, but is expected to be 34 mm. mm~42 mm.

[0040] The toilet paper 10 of this embodiment is a double-layer toilet paper 10 formed by stacking two paper layers (first paper layer 11 and second paper layer 12) having concave portions 32 and convex portions 31 obtained through embossing. The unit area weight of each paper layer 11, 12 of this toilet paper 10, that is, the unit area weight of each layer, is 15.5 g / m². 2 ~20.0 g / m 2 The preferred value is 17.0 g / m 2 ~19.0 g / m 2 If the unit area weight of each paper layer 11 and 12 is within this range, the softness, fluffiness, and other skin-touch qualities can be fully achieved. Furthermore, the wipeability, absorbency, and consequently, the sense of security during wiping on moist skin can be fully achieved. In particular, a toilet paper roll 1 can be manufactured that has a skin-touch quality equal to or even better than existing products (often referred to as conventional products), and that has wipeability, absorbency, and consequently, the sense of security during wiping on moist skin equal to existing products (often referred to as smart toilet products), making it difficult for consumers to be dissatisfied with its quality and functionality.

[0041] The thickness of the toilet paper 10, i.e., the thickness of the double layer, is preferably 200 μm to 300 μm, more preferably 230 μm to 290 μm. Within this thickness range, toilet paper rolls 1 that are unlikely to cause consumer dissatisfaction in terms of quality and function can be manufactured. The weight per unit area can be adjusted by, for example, the weight per unit area of ​​the fibers, the wrinkling rate, etc.; the paper thickness can be adjusted by whether calendering is performed, the calendering pressure, the embossing process, the wrinkling rate, etc.

[0042] The method for determining the weight per unit area (basis weight) follows the provisions of JIS P 8124. The method for determining paper thickness is as follows: After the test piece is fully conditioned (usually for about 8 hours) under the conditions specified in JIS P 8111 (1998), the thickness is directly measured under the same conditions using a dial-type thickness gauge (thickness measuring instrument) "PEACOCK H type" (manufactured by Ozaki Corporation). Specifically, after confirming that there is no debris or dust between the plunger and the measuring stage, the plunger is lowered onto the measuring stage, the scale of the aforementioned dial-type thickness gauge is moved to zero, then the plunger is lifted and the sample is placed on the test stage. The lever is then lowered all at once from the state where the plunger is opened to 700 μm, and the gauge reading is taken at this point. During measurement, only the plunger is placed without pressing it. The 10 mm diameter circular plane of the plunger terminal is perpendicular to the paper plane, and the load during this paper thickness measurement is approximately 70 gf. It should be noted that the paper thickness is the average value obtained from 10 measurements.

[0043] On the other hand, the degree of dissociation and freeness of the toilet paper in this embodiment is preferably 500cc or more and 650cc or less, more preferably 500cc or more and 620cc or less, and particularly preferably 500cc or more and 590cc or less. The degree of dissociation and freeness can be adjusted by the beating degree of the pulp fibers. In other words, the smaller the value of the degree of dissociation and freeness, the higher the degree of beating of the pulp fibers; the higher the value, the lower the degree of beating of the pulp fibers. This range of degree of dissociation and freeness is slightly higher than that of toilet paper in the general product group. By setting the beating degree of the pulp fibers to a low beating degree, setting the degree of dissociation and freeness within the above range, and adopting other configurations of the present invention, it is particularly easy to simultaneously achieve the same quality as conventional products and the same function as products for smart toilets.

[0044] It should be noted that the degree of dissociation and freeness is determined according to JIS P 8220-1, JIS P 8220-2:2012 (Pulp - Dissociation Method), using the Canadian Standard Freeness Method of JIS P 8121-2:2012 (Test Method for Freeness of Pulp), for pulp obtained by dissociating toilet paper using a standard dissociation machine. More specifically, the degree of dissociation and freeness is determined as follows. It should be noted that in the following tests, the same sample is tested twice, and the measured value is the average. If the difference between the two measured values ​​and the average value is 2% or more, an additional test is performed.

[0045] (Dissociation of toilet paper)

[0046] For the paper layer (toilet paper), tear the sample by hand into pieces approximately 2 cm in size, and prepare 30 ± 0.5 g under absolute dryness. Immerse the 30 ± 0.5 g of torn paper layer in 2000 mL of water for 4 hours or more (concentration of 1.5% by mass). Note that the water temperature at this time should be 20 ± 5°C.

[0047] After 4 hours or more, place 30 ± 0.5 g of paper and 2000 mL of water into a standard dissociation apparatus. After confirming the water temperature, dissociate for 10 minutes.

[0048] Ten minutes later, collect one cup of the solution using a spoon into a graduated cylinder, dilute with water, and visually confirm whether the fibers have dissociated. If sufficient dissociation is confirmed, perform a freeness test on the dissociated solution as described below. If dissociation is insufficient, repeat the dissociation process. This time, visually confirm the fibers have dissociated at 2-3 minute intervals, repeating the operation until dissociation is achieved. However, the maximum interval is 30 minutes. In this way, fiber dissociation can be performed with almost no change to the original properties of the fibers. It should be noted that the dissociation count of 1230 rpm on the standard dissociation machine is the count value after the dissociation machine has been running for 10 minutes.

[0049] (Determination of free radicals)

[0050] The following determination shall be performed using the Canadian Standard Freeness Tester (JIS P8121-2 2012) in accordance with the Canadian Standard Freeness Test. The Canadian Standard Freeness Tester shall use the tester of the following specifications or similar equipment.

[0051] The filter cylinder is, for example, a bronze cylinder with a sieve plate at its bottom (a circular plate with 97 holes of 0.5 mm diameter per 1 cm²). The stopcock for air input has an orifice diameter of 4.8 mm. The measuring funnel is, for example, made of brass, with an upper open section diameter of 203 mm and a total length of 278 mm. The apex angle of the main conical section is machined to 29.5 ± 0.5°. Additionally, the funnel has a precisely machined bottom hole and a side tube. The minimum diameter of the bottom hole is 3.1 mm, and it is adjusted to discharge 530 ± 5.3 mL of water per minute when 725 ± 5 mL (20 ± 5°C) of water is supplied to the funnel per minute. The side tube is a hollow tube with an inner diameter of 12.7 mm, penetrating the wall of the funnel. This results in a water volume of 23.5 ± 0.2 mL between the bottom of the funnel and the overflow level.

[0052] Next, a test solution with a solid component concentration of 0.3% by mass is prepared from the dissociation solution obtained by the above-mentioned "(dissociation of toilet paper)".

[0053] First, dilute the dissociation solution obtained through the above "(dissociation of toilet paper)" to a concentration of 0.3~1.0% by mass. Collect approximately 500 g of the diluted sample, place it in a weighing container, and weigh it with an accuracy of less than 0.5 g (weighing value A).

[0054] Next, filter paper No.2 was placed in a hot air dryer (105 ± 2°C) and dried to constant weight, and weighed with an accuracy of 0.01 g (weighing value B).

[0055] The No. 2 filter paper was placed in a Buchner funnel and moistened with water, and suction was initiated. Next, approximately 500g of the collected sample was transferred to the Buchner funnel, and moisture was suctioned out. After suction was complete, the No. 2 filter paper containing fibers was removed and passed twice through a paper sample dryer set to 120°C. It was then placed in a hot air dryer (105 ± 2°C) for 10 minutes and removed. The mass of the removed No. 2 filter paper containing fibers was weighed to an accuracy of 0.01 g (weighing value C).

[0056] After obtaining the weighing values ​​A~C as described above, the solid component concentration X (mass%) of the sample is calculated using the following formula (rounded to the nearest 0.01).

[0057] Solid component concentration X = ((weighed value C) - (weighed value B)) / (weighed value A)) × 100

[0058] Based on the calculated solids concentration X (mass%), the amount of diluted dissociated liquid collected, D, is determined using the following formula, containing 3 g of absolutely dry pulp.

[0059] Collection amount D (g) = 300 ÷ X

[0060] Dissociated solution D(g) containing 3 g of absolutely dry pulp was placed into a 1000 mL graduated cylinder and diluted to 1000 mL to prepare a test solution with a solid content of 0.3% by mass. The temperature at this point was measured with an accuracy of 1°C.

[0061] Next, the prepared test solution was tested using the aforementioned Canadian standard free concentration tester. It is important to note that when injecting the test solution into the tester, the opening of the graduated cylinder should be blocked with the palm of the hand, and the solution should be inverted and stirred approximately three times. After injecting the test solution, allow the filtered water to flow down after 5 seconds.

[0062] After stopping the drainage from the side tube, weigh the volume of water discharged from the side tube with an accuracy of 0.1 g and convert the mass to volume (mL). Next, according to Appendix D of JIS P 8121-2 2012, "Correction Table for Freeness at 20°C," and the water temperature of the test solution, correct the measured value to the freeness at a standard temperature of 20°C. The average of these corrected values ​​at 20°C is taken as the degree of dissociation. Note that the accuracy is set to 1 mL. Furthermore, if the concentration does not precisely reach 0.3% by mass, perform concentration correction according to Appendix C of JIS P 8121-2 2012, "Correction Table for Freeness at 0.30% Concentration."

[0063] On the other hand, the fibers constituting the toilet paper of this embodiment are not necessarily limited, but it is preferable that 60% or more and 85% or less of the constituent fibers are from hardwood pulp. Particularly preferred are hardwood pulps with 65% or more and 80% or less. Hardwood pulps have short fiber lengths, which makes it easier to achieve a good paper surface texture. Furthermore, because hardwood pulps have short fiber lengths, their absorbency and strength are less likely to decrease. However, the toilet paper of this embodiment, by employing low beating, slightly increases the degree of dissociation and freeness, thus fully exhibiting strength and absorbency. It should be noted that known hardwood pulps include LBKP (hardwood kraft pulp), LUKP, and LOKP, but bleached LBKP is preferred. It should also be noted that fibers other than hardwood pulp are preferably from softwood pulp. In this case, chlorinated bleached NBKP (softwood kraft pulp) is preferred.

[0064] Here, the toilet paper of this embodiment preferably has a ratio of longitudinal dry tensile strength to transverse dry tensile strength (longitudinal dry tensile strength / transverse dry tensile strength) of 2.9 or more and 3.8 or less. More preferably, it is 3.0 or more and 3.7 or less. Here, the longitudinal direction, also known as the MD direction, is the flow direction during papermaking. The transverse direction, also known as the CD direction, is the direction perpendicular to the flow direction during papermaking (MD direction). This aspect ratio is higher than that of conventional products and close to that of products used in smart toilets. This aspect ratio can be adjusted by the J / W ratio during papermaking. It is speculated that by setting this aspect ratio, the elasticity of the paper layer, especially as described later, will be improved.

[0065] Furthermore, the ratio of the transverse wet tensile strength to the transverse dry tensile strength (transverse wet tensile strength / transverse dry tensile strength) of the toilet paper in this embodiment is preferably 0.20 to 0.40. More preferably, it is 0.21 to 0.35. Regarding the tensile strength of toilet paper, the transverse value is generally lower than the longitudinal value. The inventors have found that this lower transverse tensile strength, when dry and wet, can sometimes affect the feeling when wiping away moisture. In other words, the smaller the difference in transverse tensile strength when dry and wet, the easier it is to obtain a strong and reassuring feeling when wiping away moisture. Therefore, for example, it can sometimes affect the feeling of reassurance when wiping away moisture adhering to the skin after washing when using it on a toilet with a washing function. The ratio of the longitudinal wet tensile strength to the longitudinal dry tensile strength (longitudinal wet tensile strength / longitudinal dry tensile strength) of the toilet paper in this embodiment is preferably 0.10 to 0.25. This value is considered comparable to that of existing conventional products and products used in smart toilets. The degree of strength reduction in the longitudinal direction is the same as existing products, and the impact on the perceived strength and comfort caused by the ratio of transverse wet tensile strength to transverse dry tensile strength (transverse wet tensile strength / transverse dry tensile strength) is minimal. The adjustment of the ratio of transverse wet tensile strength to transverse dry tensile strength (transverse wet tensile strength / transverse dry tensile strength) and the ratio of longitudinal wet tensile strength to longitudinal dry tensile strength (longitudinal wet tensile strength / longitudinal dry tensile strength) of the toilet paper in this embodiment can be adjusted by the J / W ratio during papermaking. However, in this case, the adjustment is to slightly increase the longitudinal tensile strength and slightly decrease the transverse tensile strength. By optimizing this adjustment, the range of dissociation and freeness, and the lamination and embossing processes described later, the ratio of transverse wet tensile strength to transverse dry tensile strength (transverse wet tensile strength / transverse dry tensile strength) can be appropriately adjusted to the aforementioned range.

[0066] Here, the tensile strength of the toilet paper in this embodiment is not necessarily limited, but the longitudinal dry tensile strength is preferably 250 cN / 25 mm or more and 360 cN / 25 mm or less, and the transverse dry tensile strength is preferably 65 cN / 25 mm or more and 120 cN / 25 mm or less. This dry tensile strength, both longitudinally and transversely, is within the lower range of the nested lamination technology. In particular, the transverse dry tensile strength is comparable to or lower than that of conventional products without lamination technology. The lower longitudinal dry tensile strength improves the smoothness of the skin feel, and the lower transverse dry tensile strength improves softness. Furthermore, the longitudinal wet tensile strength is set to 40 cN / 25 mm or more and 80 cN / 25 mm or less, and the transverse wet tensile strength is set to 16 cN / 25 mm or more and 35 cN / 25 mm or less. The transverse wet tensile strength is in a slightly higher range than that of products without lamination technology. This range can be achieved by improving the J / W ratio and sizing during the papermaking process.

[0067] The dry tensile strength was determined based on JIS P 8113 (2006) and was measured as follows. Test pieces approximately 25 mm wide (± 0.5 mm) × 150 mm long were used in both the longitudinal and transverse directions. The test pieces were measured directly in multiple layers. The testing machine used was the Minebea TG-200N tensile testing machine with a force sensor, manufactured by Minebea Corporation, or similar equipment. The clamp spacing was set to 100 mm, and the tensile speed was set to 100 mm / min for longitudinal measurements and 50 mm / min for transverse measurements. The measurement was performed as follows: the two ends of the test piece were secured to the clamps of the testing machine, a tensile load was applied to the paper in the vertical direction, and the reading at the point of paper breakage (digital value) was recorded. Five sets of samples were prepared for both the longitudinal and transverse directions, and five measurements were performed in each direction. The average value of the measured values ​​was taken as the dry tensile strength in each direction.

[0068] The wet tensile strength was determined based on JIS P 8135 (1998) and was measured as follows. Test pieces were cut to approximately 25 mm (± 0.5 mm) wide and 150 mm long in both the longitudinal and transverse directions. In the case of multi-layered toilet paper, the test was performed directly in a multi-layered configuration. The testing machine used was the Minebea TG-200N tensile testing machine with a force sensor, manufactured by Minebea Corporation, or similar equipment. It is important to note that the clamp spacing was set to 100 mm and the tensile speed to 50 mm / min. Test pieces were used that had been cured in a dryer at 105°C for 10 minutes. The measurement was performed as follows: After securing both ends of the test piece to the clamps of the testing machine, water was applied horizontally to the center of the test piece using a flat-headed brush with a water content of approximately 10 mm. Immediately afterwards, a tensile load was applied to the paper in the vertical direction, and the reading at the point of paper breakage (digital value) was recorded. Five sets of samples were prepared in both the longitudinal and transverse directions, and five measurements were performed in each direction. The average value of the measured values ​​was taken as the wet tensile strength in each direction.

[0069] On the other hand, while the toilet paper of this embodiment can contain known dry strength agents, dry strength agents, and temporary wet strength agents, paper strength agents may reduce softness and hydrolysis, so it is preferable not to add these paper strength agents. Therefore, the toilet paper of this embodiment preferably does not contain at least one of the dry strength agents, dry strength agents, and temporary wet strength agents, more preferably does not contain two of them, and most preferably does not contain any of them. Based on the essential components of this invention, such as degree of dissociation, tensile strength, and lamination embossing, as well as the technical knowledge of those skilled in the art, the toilet paper of this embodiment can be made into toilet paper with sufficiently excellent quality and function even without the use of paper strength agents.

[0070] Furthermore, the toilet paper of this embodiment preferably contains a softener. Examples of softeners include fatty acid ester softeners and cationic fatty acid amide softeners. Fatty acid ester softeners can be any of cationic fatty acid ester compounds or nonionic fatty acid ester compounds, and multiple types may be added. Alternatively, examples of cationic fatty acid amide softeners include reactants obtained by reacting amide compounds obtained from the reaction of polyalkylene polyamines with monocarboxylic acids and epoxy halides. The content of the softener is not necessarily limited, but it is desirable to contain 0.5 to 4.0 kg / t of pulp.

[0071] On the other hand, the toilet paper of this embodiment has the aforementioned paper material, and, as a mechanical structure, such as Figure 2 and Figure 3As shown, particularly on each of the first paper layer 11 and the second paper layer 12 constituting the toilet paper 10, recesses 32 are provided on one side and protrusions 31 corresponding to the recesses 32 are provided on the other side through embossing. In particular, the protruding surfaces of these paper layers are stacked in an opposing manner, and are bonded together at the top of the protrusions 31 by an adhesive to form a laminated, integrated structure. Therefore, the toilet paper of this embodiment has a form in which only recesses 32 exist on the front and back sides.

[0072] The top view shape of each recess 32 is not limited. Furthermore, it is not necessary for them all to be the same shape. From the viewpoint of softness and skin-touch feel, a shape without corners is desirable for the recess 32; specifically, a circle, ellipse, rounded triangle, rounded quadrilateral, or rounded polygon are preferred. A circle or ellipse is particularly preferred. The area of ​​the recess 32 is preferably 0.5 mm. 2 ~8 mm 2 1.0 mm is particularly preferred. 2 ~3.2 mm 2 .

[0073] The embossed area ratio (total area of ​​recesses / total area of ​​paper layers) of the toilet paper 10 in this embodiment is not necessarily limited, but is preferably 15% to 28%. In each surface of the first and second paper layers, it is preferably 8% to 14%. Here, the embossed area ratio of the toilet paper in this embodiment is a value obtained by measuring a sample taken from the end of the roll side, excluding the tail seal.

[0074] The arrangement (embossed pattern) of the recesses 32 in the toilet paper 10 of this embodiment is not limited. As one example, such as... Figure 3 As shown, arranging the recesses 32 appropriately as a whole to depict appropriate geometric patterns such as flowers and heart shapes is preferred in terms of appearance.

[0075] Here, in this embodiment, the first paper layer 11 and the second paper layer 12 of the toilet paper 10 are stacked in a so-called tip-to-tip configuration where the protrusions of the first paper layer and the protrusions of the second paper layer face each other. Figure 2As shown, the toilet paper can be in a nested form where the protrusions 31 of the first paper layer 11 are opposite to the portions other than the protrusions 31 of the second paper layer 12, and the protrusions 31 of the second paper layer 12 are opposite to the portions other than the protrusions 31 of the first paper layer 11. The nested form is particularly preferred. Because the positions of the recesses on the front and back sides differ, the nested form easily exhibits the softness of the toilet paper. Furthermore, the increased number of columnar protrusions 31 between the paper layers makes it difficult for the gaps between the layers to be crushed, thus improving the wiping performance, absorbency, and overall comfort when wiping moist skin. Furthermore, the thickness can be thinner than the top-to-top form. Therefore, in roll-up configurations like toilet paper where a specified length needs to be contained within a specified roll diameter, compared to the top-to-top form, the nested form allows each paper layer to have a high weight per unit area and low density, and is wound more loosely. Therefore, the embossing process makes the raised and recessed areas less likely to be crushed, resulting in superior quality and functionality.

[0076] Furthermore, while the first paper layer 11 and the second paper layer 12 in the toilet paper 10 of this embodiment can be bonded at all the protrusions 31, it is not necessary to bond them at all the protrusions 31. As a preferred method, instead of applying adhesive to the protrusions 31 of the second paper layer 12 located on the inner surface side of the roll, the first paper layer 11 and the second paper layer 12 are bonded by applying adhesive to all or part of the protrusions 31 of the first paper layer 11 located on the outer surface side of the roll. Because there is no bonded portion near the outer surface side of the roll, the toilet paper roll made in this manner is particularly easy to feel soft when holding the roll.

[0077] Furthermore, the adhesive area ratio (total area of ​​the adhesive portion / total area of ​​the paper layer) in the toilet paper 10 of this embodiment is not necessarily limited, but it is particularly desirable to be 20% or less. Additionally, a lower limit of 9% is particularly desirable. If the adhesive area ratio is 20% or less, it is particularly difficult to perceive the stiffness of the toilet paper resulting from the lamination and embossing technology. It should be noted that the adhesive area ratio of the toilet paper in this embodiment is a value obtained by measuring a 30 cm sample taken from the end of the roll, excluding the tail seal.

[0078] The type of adhesive used in the toilet paper of this embodiment is not necessarily limited. Preferred adhesives are water-soluble adhesives such as PVA (polyvinyl alcohol) and CMC (carboxymethyl cellulose), and particularly preferred are water-soluble cellulose adhesives, namely CMC.

[0079] Regarding the composition of the toilet paper in this embodiment, four sheets of toilet paper can be stacked, so that when pressed into the testing terminal by a compression tester, the pressure drops from 0.5 gf / cm. 2 Position under load: T0 to 50 gf / cm2 The displacement (T0-Tm) between positions T0 and Tm under load is called elasticity, which is 1.0 mm or more. Therefore, the toilet paper of this embodiment preferably has an elasticity of 1.0 mm or more. Elasticity can be measured using a KES-G5 (manufactured by Kato Tech Co., Ltd.) or similar equipment. The measuring terminal uses the 2 cm standard terminal attached to the KES-G5. 2 Or similar measuring terminals (circular, with a flat measuring surface and an area of ​​2 cm²) 2 More specifically, such as Figure 4 As shown, four sheets of toilet paper 10 are stacked on the measuring platform or a rigid horizontal platform 40 of the compression testing machine and left to stand. The measuring surface is moved at a speed of 0.02 mm / s to a depth of 2 cm. 2 The flat measuring terminal was pressed onto these tissues, and its 0.5 gf / cm² value was measured. 2 The pressure point T0 under load and the load increased to 50 gf / cm 2 The difference between the pressing position Tm and the actual pressing position is taken as the value of the stretchability. It should be noted that the sample is the paper width (roll width) × 100 mm. Stretchability particularly affects qualities such as softness and fluffiness in the thickness direction. In the product group for smart toilets, since the emphasis is on ensuring the gaps between paper layers through lamination and embossing technology, the stretchability is generally around 0.5 mm to 0.7 mm. Stretchability exceeding 1.0 mm is at the same level as or even higher than that of conventional products. As described above, in the composition of the toilet paper of the present invention, the stretchability can be 1.0 mm or more. In particular, by adjusting at least one of the above-mentioned embossing-related components such as the lamination pattern, embossing area ratio, adhesive area ratio, and adhesive type within the above range, it is easier to obtain this stretchability value. Furthermore, the stretchability of the toilet paper in this embodiment is sampled from a position 1% to 15% from the end of the toilet roll. If the stretchability at this position is within the above range, the unevenness formed by the embossing process will not be crushed, achieving a sufficiently satisfactory effect in terms of quality.

[0080] It should be noted that the toilet paper in this embodiment uses an attached standard terminal 2 cm. 2The KES-G5 (manufactured by Kato Tech Co., Ltd.) and similar equipment can be used to measure the compression characteristic LC value, which can be measured simultaneously with or separately from the aforementioned extensibility, preferably in the range of 0.35 to 0.70; the compression energy WC value, preferably in the range of 1.25 to 1.75; and the resilience RC value, preferably in the range of 40 to 50. These values ​​are equivalent to or even higher than those of conventional products and products used in smart toilets. The closer the compression characteristic LC value is to 1.0, the more rigid the product is considered to be under compression; the higher the compression energy WC value, the easier it is to compress; and the closer the resilience RC value is to 100, the better the resilience is considered.

[0081] Here, the toilet paper of this embodiment preferably has an HF (hand feel) value of 94 or higher, as measured by a TSA (Toilet Paper Softness Measurement) device. In the composition of the toilet paper of this embodiment, the HF (hand feel) value can be 94 or higher. An HF (hand feel) value of 94 or higher is a high value, equivalent to or even higher than that of conventional products. It should be noted that the HF (hand feel) value is measured on the outer surface of the roll. It should also be noted that the test sample is taken from a position 1% to 15% from the end of the toilet paper roll.

[0082] The paper softness measuring device TSA is manufactured by Emtec Electronic GmbH (Japan's agent is Rufuto Co., Ltd.) of Germany. The feel of toilet paper is affected by its characteristics such as "smoothness / roughness," "softness," and "stiffness." The TSA can quantify these three characteristics using acoustic and deformation measurements (represented as TS750, TS7, and D, respectively). Furthermore, based on these parameters (raw data) and the toilet paper's weight per unit area, thickness, and number of layers, the TSA uses a non-linear algorithm to calculate the HF (hand feel) value. It should be noted that the HF value algorithm used in this invention and embodiment is TPII. The HF value is a comprehensive quantitative evaluation of the tactile feel of toilet paper in relation to the results of a human tactile panel test (sensory test). In the TSA test of the paper softness measuring device in this embodiment, the sample is processed into a circle with a diameter of approximately 112.8 mm using a sample punch from Emtec Corporation, and the software for analysis and numericalization is the Emtec Measurement System.

[0083] Here, the TS750 value of the toilet paper in this embodiment is 20 dBV. 2 rms~35dBV 2TS750 refers to the intensity of the first maximum peak in the spectrum observed from the low-frequency side when a bladed rotor is pressed into a sample stage with a pressure of 100 mN from above and rotated at a speed of 2.0 revolutions per second, using a vibration sensor to measure the vibration of the sample stage. TS750 is a parameter affected by "smoothness / roughness". Regarding the value of TS750, the smaller the value, the better the "smoothness". Specifically, the value of TS750 can be set within the above range based on factors such as wrinkling rate, weight per unit area, paper thickness, longitudinal and transverse dry tensile strength, aspect ratio, and the unevenness created by embossing.

[0084] Furthermore, the TS7 value of the toilet paper in this embodiment is preferably 7.0 dBV. 2 rms~10.0dBV 2 RMS. It's important to note that the TS7 value refers to the intensity of the maximum peak in a frequency spectrum containing 6500 Hz obtained by measuring the vibration of the sample stage when a bladed rotor is pressed in from above with a pressure of 100 mN and rotated at 2.0 rpm on a sample stage. This TS7 value is a parameter primarily influenced by aspects of "softness," including bulkiness, surface softness, and fluffiness. Regarding the TS7 value, the lower the value, the better the "softness." The TS7 value can be specifically set within the above range based on factors such as unit area weight, paper thickness, longitudinal and transverse dry tensile strength, aspect ratio, stretchability, embossing processes creating raised or recessed areas, especially the number of recesses, or the amount of adhesive used.

[0085] Furthermore, the D value of the toilet paper in this embodiment is preferably 3.5 mm / N to 4.0 mm / N. It should be noted that the D value is expressed as the amount of vertical deformation displacement of the sample placed on the sample stage when, without rotating the bladed rotor of the measuring device, it is pressed from above with pressing pressures of 100 mN and 600 mN, respectively. This D value is a parameter affected by stiffness. The D value can also be specifically set to the above range based on factors such as unit area weight, paper thickness, longitudinal and transverse dry tensile strength, aspect ratio, extensibility, the number of embossed features, particularly the number of recesses, or the amount of adhesive used.

[0086] On the other hand, the absorbency of the toilet paper in this embodiment is preferably 0.60 or higher. Here, absorbency is measured by dripping water onto a small point on a stacked sample of 20 sheets of toilet paper at a constant speed until the water penetrates to the surface opposite to the dripping point. The test method is as follows: Ten sheets of toilet paper are stacked together and fixed in a stacked state by a sample clamp. A water detection device is placed at the position below the sample, in contact with the sample. The water is detected from the center of the clamp. Water is dripped onto the same part of one side of the sample at a rate of 10 ± 2 mL / min from a position 10 mm above the exposed part of the sample through the 21 mm circular opening. The amount of water that drips when the detection device detects water is recorded as the water absorption force.

[0087] On the other hand, the hydrolytic properties of toilet paper are specified as less than 100 seconds in the looseness test of JIS P 4501 (1993), but in the composition of the toilet paper in this embodiment, it can be less than 25 seconds, and particularly less than 20 seconds. This is very high compared to products used in smart toilets. Based on this, the hydrolytic properties of the toilet paper in this embodiment are preferably less than 25 seconds, and more preferably less than 20 seconds. It should be noted that in the looseness test of JIS P 4501 (1993), the test piece used in the test is set to 114 ± 2 mm square, based on a toilet paper width of 114 mm. However, in the toilet paper of this embodiment, when the roll width is set to 114 mm or less, the test piece is a test piece of roll width × 114 mm.

[0088] Furthermore, the toilet paper of this embodiment is expected to have an MMD of 11.0 or less. If the MMD is set to 11.0 or less while using lamination and embossing technology, it is difficult to perceive a firm texture against the skin. It should be noted that the MMD... Figure 5 The measuring apparatus 100 shown involves bringing the contact surface of a friction element into contact with the surface of a test sample subjected to a tension of 20 g / cm in a specified direction, with a contact pressure of 25 g. Simultaneously, the friction element is moved 2 cm at a speed of 0.1 cm / s in approximately the same direction as the applied tension. The coefficient of friction at this moment is measured using a friction tester KES-SE (manufactured by Kato Tech Co., Ltd.) or a similar device. The value obtained by dividing the coefficient of friction by the friction distance (movement distance = 2 cm) is the MMD. The friction element is formed by 20 adjacent piano wires P with a diameter of 0.5 mm, and has a contact surface formed with a length and width of 10 mm. At the front end of the contact surface, a unit bulge formed by the 20 piano wires P (radius of curvature 0.25 mm) is formed.

[0089] Furthermore, the softness of the toilet paper in this embodiment is preferably 3.0 cN / 100 mm or less, and particularly preferably 2.8 cN / 100 mm to 1.0 cN / 100 mm. This softness is determined based on the Handle-O-Meter method according to JIS L 1096 (2010) E method.

[0090] In the toilet paper of this embodiment, if the MMD and softness are within the above range, it can be said that the surface quality and softness are within the range that consumers can be satisfied with.

[0091] On the other hand, the winding density of the toilet paper roll in this embodiment is 0.85 or less, preferably 0.85 or less and 0.70 or more, and particularly preferably 0.80 or less and 0.72 or more. By setting this winding density range, the concave and convex portions formed by the embossing process are less likely to be crushed, making it easier to balance quality and function. It should be noted that the winding density is calculated by (paper thickness × roll length × number of layers) ÷ (cross-sectional area of ​​the roll). In addition, the cross-sectional area of ​​the roll is calculated by {cross-sectional area of ​​the roll diameter (outer diameter) L1 portion} - (cross-sectional area of ​​the paper tube outer diameter L3 portion).

[0092] On the other hand, the preferred winding stiffness of the toilet paper in this embodiment is 0.40 kgf to 0.70 kgf. Winding stiffness is determined by measuring the force required to pull the π ruler scale three graduations outwards by winding the toilet paper circumferentially around the center between the end faces using a caliper (manufactured by MURATEC-KDS Co., Ltd.) or a similar device, and using a force gauge (manufactured by IMADA Co., Ltd.) or a similar device. Winding stiffness affects the feel of the toilet paper when held and the deformability of the toilet paper itself. A winding stiffness in the range of 0.40 kgf to 0.70 kgf is comparable to that of conventional products and lower than that of products used in smart toilets. In this preferred embodiment of toilet paper, the irregularities formed by embossing are adequately maintained within the roll, and the winding is performed with a margin sufficient to allow the irregularities to be crushed and deformed even under the same load as conventional products. On the other hand, the paper layers are neither stiff nor excessively crushed due to lamination and embossing with adhesives during winding. Therefore, in terms of quality, it gives an impression close to that of a regular product.

[0093] On the other hand, the roll tightness of the toilet paper in this embodiment is preferably 2.0 mm or more and 5.0 mm or less, particularly preferably 2.1 mm or more and 4.5 mm or less. Furthermore, the roll stiffness is preferably 7.0 mm or more and 13.0 mm or less, particularly preferably 7.2 mm or more and 12.5 mm or less. Further, the roll softness is preferably 4.0 mm or more and 10.0 mm or less, particularly preferably 4.5 mm or more and 9.5 mm or less. In the above-mentioned roll length, roll diameter, and toilet paper configuration, the roll tightness, roll stiffness, and roll softness of the toilet paper in this embodiment can be adjusted to the above ranges by adjusting the winding speed and winding tension during manufacturing.

[0094] Here, the roll tightness of the toilet paper in this embodiment refers to, for example, Figure 6 As shown, when the measuring terminal is pressed into the center of the circumference of toilet paper roll 1 in the width direction using a compression tester, the pressure drops from 0.5 gf / cm. 2 Position under load: T0 to 500 gf / cm 2 The displacement between positions T0 and Tm under load (T0-Tm). The tightness of the paper roll winding can be measured using the KES-G5 (manufactured by KatoTech Co., Ltd.) and similar equipment. The measuring terminal uses the 2 cm standard terminal included with the KES-G5. 2 Or similar measuring terminals (circular, with a flat measuring surface and an area of ​​2 cm²) 2 More specifically, such as Figure 6 As shown, on the testing platform of the compression testing machine or a rigid horizontal platform 40, the toilet paper roll 1 is placed statically with the axis transverse, and the measuring surface is moved at a speed of 0.02 cm / s. 2 The flat measuring terminal 41 is pressed from above toward the center of the width direction of the toilet paper roll 1 in a radial direction, and its value of 0.5 gf / cm is measured. 2 The indentation position T0 under load and the load increased to 500 gf / cm 2 The difference between the pressing position Tm and the actual pressing position is taken as the value of the paper roll winding tightness.

[0095] The roll paper winding stiffness in this embodiment of the toilet paper roll 1 is as follows: Figure 7 As shown, a 2 mm thick, 80 mm × 140 mm, 26.5 ± 0.2 g acrylic plate 42 is sandwiched between the toilet paper roll 1 and the measuring terminal 41. The plate is 0.5 gf / cm², and its thickness was measured in the same manner as the toilet paper roll winding tightness. 2 Position under load: T0 to 500 gf / cm 2 The displacement (T0-Tm) between positions Tm under load. However, the moving speed of the measuring terminal is set to 0.01 cm / second.

[0096] The toilet paper roll of this embodiment has a softness, such as... Figure 8 As shown, an acrylic core 43 with an inner diameter of ± 2 mm is inserted into the paper tube of the toilet paper roll. The displacement amount is obtained by measuring the same amount as the roll winding tightness mentioned above. However, the displacement amount is set to 0.5 gf / cm. 2 Position under load: T0 to 150 gf / cm 2 The displacement between positions T0 and Tm under load (T0-Tm). Additionally, the moving speed of the measuring terminal is set to 0.02 cm / second.

[0097] Here, the tightness of the toilet paper roll can be described as its susceptibility to deformation when pressed in a narrow, localized area around the roll's perimeter, while the hardness of the roll can be described as its susceptibility to deformation when pressed over a large area around the roll's perimeter. The softness of the roll can be described as the suppleness of the wound portion. These factors—tightness, hardness, and softness—can also be considered indicators of the roll's deformability and its overall condition within its roll form. Especially when these indicators are within the specified ranges, it means that the embossing process has not resulted in crushing or the degree of crushing is within an appropriate range. The paper quality, including the degree of dissociation and tensile strength, is not compromised. In terms of quality and function, the toilet paper is wound in a very satisfactory paper layer state. It should be noted that by adjusting at least one of the embossing-related factors such as the layering pattern, embossing area ratio, adhesive area ratio, and adhesive type within the specified ranges, it is easy to bring the tightness, hardness, and softness of the roll into these numerical ranges.

[0098] Example

[0099] Next, the physical properties of the toilet paper rolls of the present invention, including examples, comparative examples, and conventional examples, were measured. The results are shown in Table 1, and the methods for measuring each physical property and characteristic are as described above. Furthermore, the embossing process was used to create the raised or recessed areas, except for conventional examples 1 to 5 which are commercially available products. Figure 3 The patterns shown are as follows. Regarding the layering form, each embodiment and Comparative Example 1 is a nested form. Comparative Example 2 and Existing Example 2 are top-to-top forms. Existing Examples 3 and 4 are single-sided embossed forms. Existing Examples 1 and 5 are non-laminated embossed forms; although they are double-sided embossed with opposing protrusions, they achieve integrated layering through edge embossing, and the positions of the protrusions are not specified. The embossing area ratio in the embodiments and comparative examples is approximately 10% on both the front and back sides, totaling approximately 20%. The adhesive area ratio is set to 10%. In addition, no dry strength agent, wet strength agent, or temporary wet strength agent is added to the toilet paper in the embodiments and comparative examples. The softener is used in the same proportion in the embodiments and comparative examples. Furthermore, CMC (carboxymethyl cellulose) is used as the adhesive in the embodiments and comparative examples.

[0100] It should be noted that Existing Example 1 refers to toilet paper from the product group called "regular products," while Existing Examples 2 and 5 are products with lower weight per unit area from the product group for smart toilets. In other words, these are products whose weight per unit area is reduced to be equal to or lower than that of regular products in order to exhibit softness, etc. Existing Example 3 is a product from the product group for smart toilets that uses a single-sided embossing process, and Existing Example 4 is a product from the product group for general smart toilets.

[0101] [Table 1]

[0102] As shown in Table 1, the toilet paper rolls of the embodiments for which all values ​​of TS7, TS750, and D fall within the scope of this invention achieve values ​​equal to or even higher than those of conventional products (Existing Example 1) in terms of softness and HF (hand feel). In terms of quality, they are equivalent to conventional products. The values ​​are significantly higher than those of products for smart toilets (Existing Examples 2 to 4). Furthermore, the wet tensile strength and other strengths are significantly higher than those of conventional products (Existing Example 1), close to those of products for smart toilets (Existing Examples 2 to 4), and higher than those of Existing Example 5.

[0103] Comparative Example 1 is presumably due to the aspect ratio, the stretch value is outside the range of the embodiment, and the HF (hand feel) value is the same as that of the product group used in smart toilets, and a sufficient improvement has not been achieved.

[0104] Therefore, the embodiments of the present invention combine the softness, fluffiness and other skin-touch qualities of conventional products with the strength, absorbency and other functional properties of paper used in smart toilets, making it a toilet paper roll that is unlikely to cause dissatisfaction whether used in regular scenarios or on a toilet with a cleaning function.

[0105] Figure Labels

[0106] 1… Toilet paper roll, 10… Toilet paper, 11… First paper layer, 12… Second paper layer, 20… Paper tube (core), 31… Protrusion, 32… Recess, 40… Horizontal platform (measuring platform), 41… Measuring terminal, 42… Acrylic plate, 43… Acrylic core, L1… Roll diameter of toilet paper roll, L3… Diameter of toilet paper roll core, L2… Width of toilet paper roll.

Claims

1. A type of toilet paper roll, comprising two layers of paper stacked together, wound into a paper tube with a roll length of 20 m to 40 m and a roll diameter of 110 mm to 130 mm, characterized in that, In the toilet paper, paper layers with concave portions on one side and convex portions corresponding to the concave portions on the other side are stacked with their convex surfaces facing each other, and are bonded together on the top of the convex portions by an adhesive. and The TS750 value measured by the TSA paper softness testing device is 20 dBV. 2 rms~35dBV 2 The values ​​for rms and TS7 are 7.0 BV. 2 rms~10.0BV 2 The values ​​of rms and D are 3.5 mm / N to 4.0 mm / N.

2. The toilet paper roll according to claim 1, wherein, The toilet paper has a longitudinal drying tensile strength of 250 cN / 25 mm or higher and 360 cN / 25 mm or lower, and a transverse drying tensile strength of 65 cN / 25 mm or higher and 120 cN / 25 mm or lower; and The ratio of its longitudinal dry tensile strength to its transverse dry tensile strength, i.e., longitudinal dry tensile strength / transverse dry tensile strength, is 2.9 or higher and 3.8 or lower.

3. The toilet paper roll according to claim 1, wherein, When four sheets of the aforementioned toilet paper are overlapped and pressed into the testing terminal using a compression tester, the pressure drops from 0.5 gf / cm³. 2 Position under load: T0 to 50 gf / cm 2 The displacement (T0-Tm) between positions Tm under load is called extensibility, which is 1.0 mm or more.

4. The toilet paper roll according to claim 1, wherein, The ratio of the transverse wet tensile strength to the transverse dry tensile strength of the toilet paper, i.e., transverse wet tensile strength / transverse dry tensile strength, is 0.20~0.40.

Images