toilet roll

Abstract

To provide a compact toilet roll which has a long wound length without making a wound diameter so large and which combines all features of wet strength, hydrolysis, and softness of the roll.SOLUTION: The present invention is a toilet roll for which 2-ply toilet paper is taken up in a roll shape and which has a wound length of 65-105 m, a wound diameter of 105-125 mm, and a basis weight per 1-ply of the toilet paper of 11-14 g / m2. Also, wet tensile strength in the width direction (CD direction) measured with 3 layers of 2-ply toilet paper on top of each other is 0.25-0.35 N / 15 mm, and the hydrolysis of 1 sheet of toilet paper obtained by peeling the 2-ply toilet paper is 5-16 seconds.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a toilet roll in which two-ply toilet paper is wound in a roll shape.

Background Art

[0002] Roll-shaped or sheet-shaped toilet paper products are manufactured by cutting toilet paper in which one or two or more toilet paper webs are stacked to a predetermined size. Generally, toilet rolls in which long toilet paper is wound in a roll shape are widely used. Toilet paper made of one toilet paper web is called single-ply toilet paper, and toilet paper made of two stacked toilet paper webs is called two-ply toilet paper.

[0003] Toilet rolls are widely distributed, for example, packaged in units of 12 rolls or 16 rolls. However, since these packages are bulky, the amount that can be carried is limited. Also, in public facilities and the like, there is often a shortage of storage space for toilet rolls. For this reason, the use of roll products with a longer roll length by adjusting the paper thickness of the toilet paper constituting the toilet roll or increasing the winding force when winding in a roll shape is also increasing (for example, Patent Documents 1 and 2).

[0004] Patent Document 1 discloses a sanitary tissue roll in which a laminate of two sanitary tissue papers is wound in a roll shape, wherein the basis weight per sheet of the sanitary tissue paper exceeds 13 g / m 2 and is 17 g / m 2 or less, and the paper thickness exceeds 0.6 mm / 10 sheets and is 1.1 mm / 10 sheets or less, and the roll length of the sanitary tissue roll is 74 to 93 m and the roll diameter is 100 to 130 mm. Further, Patent Document 2 discloses a toilet paper roll in which a long two-ply toilet paper is wound into a roll shape, wherein each ply has a basis weight of 10 to 14 g / m 2A toilet paper roll is disclosed in which the difference in elongation rate in the longitudinal direction of each sheet is 2-10%, each sheet is integrated by a contact emboss formed at the widthwise end of the toilet paper, the diameter is 100-120 mm, and the roll length is 60-90 m. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-188342 [Patent Document 2] Japanese Patent Publication No. 2013-208297 [Overview of the initiative] [Problems that the invention aims to solve]

[0006] Toilet paper becomes wet during use and requires sufficient wet strength to prevent tearing, while also requiring sufficient water solubility to prevent clogging after flushing. However, with conventional compact toilet rolls, the decrease in basis weight inevitably leads to a decrease in wet strength, making it difficult to achieve a good balance between wet strength and water solubility.

[0007] On the other hand, while it might be possible to increase the basis weight to some extent to improve wet strength, when producing long toilet rolls from such toilet paper, it becomes necessary to tightly wind the toilet paper to increase the length, which reduces the softness of the roll itself. Such toilet rolls may lack appeal when sold.

[0008] Therefore, in order to solve the problems of the conventional technology, the inventors of this invention proceeded with research with the aim of providing a compact toilet roll that increases the length of the toilet paper without significantly increasing the diameter of the toilet roll, and that combines wet strength, water solubility, and softness of the roll. [Means for solving the problem]

[0009] Specifically, the present invention has the following configuration.

[0010] [1] A toilet roll made by winding 2-ply toilet paper into a roll, The length of the toilet roll is 65-105m, and the diameter is 105-125mm. The basis weight per ply of toilet paper is 11-14 g / m². 2 And, The wet tensile strength in the width direction (CD direction) measured by stacking three sets of 2-ply toilet paper was 0.25~0.35 N / 15 mm. A toilet roll in which a single sheet of toilet paper obtained by separating two plies of toilet paper has a water-dissolving time of 5 to 16 seconds. [2] The toilet roll according to [1], wherein the dry tensile strength in the longitudinal direction (MD direction) of the 2-ply toilet paper is 1.20 to 2.00 N / 15 mm. [3] Toilet paper contains pulp derived from coniferous trees and pulp derived from hardwoods. The pulp content derived from coniferous trees is 10-70% by mass of the total pulp mass. The toilet roll described in [1] or [2] contains 30 to 90% by mass of hardwood-derived pulp relative to the total pulp mass. [4] Toilet paper is a toilet roll made by papermaking from a fiber raw material having a freeness of 400 ml or more, as described in any of [1] to [3]. [5] The toilet roll according to any one of [1] to [4], wherein the content of the wet strength agent in the toilet paper is 0.01 part by mass or less with respect to 100 parts by mass of pulp.

Advantages of the Invention

[0011] According to the present invention, a toilet roll having all of wet strength, hydrolysis resistance, and softness of the roll can be obtained.

Brief Description of the Drawings

[0012] [Figure 1] FIG. 1 is a schematic diagram for explaining the configuration of the toilet roll of the present invention. [Figure 2] FIG. 2 is a schematic diagram for explaining the configuration of the toilet roll of the present invention.

Modes for Carrying Out the Invention

[0013] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be based on typical embodiments or specific examples, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0014] (Toilet Roll) The present invention relates to a toilet roll in which two-ply toilet paper is wound in a roll shape, the roll length of the toilet roll is 65 to 105 m, the roll diameter is 105 to 125 mm, the basis weight per ply of the toilet paper is 11 to 14 g / m 2 and the wet tensile strength in the width direction (CD direction) measured by stacking three sets of two-ply toilet paper is 0.25 to 0.35 N / 15 mm, and the hydrolysis resistance of one sheet of toilet paper obtained by peeling two-ply toilet paper is 5 to 16 seconds.

[0015] Since the toilet roll of the present invention has the above-described configuration, despite being a toilet roll with a long roll length, the roll diameter of the toilet roll is not so large, so it is excellent in portability and storage. Further, the toilet roll of the present invention has appropriate wet strength while achieving excellent hydrolysis. Furthermore, since the basis weight per ply of the toilet paper of the present invention is not so large, it is also excellent in roll softness.

[0016] Also, in the toilet roll of the present invention, since appropriate wet strength and hydrolysis are compatible, the toilet paper has a soft texture. Thus, the toilet roll of the present invention also has two characteristics that are difficult to balance, namely, strength during use and a soft texture.

[0017] FIG. 1 is a schematic diagram for explaining the configuration of the toilet roll of the present invention. In FIG. 1, a toilet roll 100 composed of two-ply toilet paper 20 is illustrated. In the toilet roll 100, of the two-ply toilet paper 20, the toilet paper 20a arranged on the outer side of the roll is referred to as the front-side toilet paper 20a, and the toilet paper 20b arranged on the inner side of the roll is referred to as the back-side toilet paper 20b. Also, the exposed surface of the front-side toilet paper 20a is referred to as the front surface, and the exposed surface of the back-side toilet paper 20b is referred to as the back surface.

[0018] The roll length of the toilet paper roll of this invention is 65 to 105 m. Preferably, the roll length of the toilet paper roll is 70 m or more. Preferably, the roll length of the toilet paper roll is 100 m or less, and more preferably 90 m or less. Toilet paper rolls with such roll lengths are sometimes called so-called long rolls. They are also sometimes called double rolls or triple rolls. Here, the roll length of the toilet paper roll refers to the roll length in units of two sheets of toilet paper stacked together. By setting the roll length of the toilet paper roll within the above range, the toilet paper roll can be used for a longer period, and the frequency of replacement can be reduced.

[0019] The roll diameter (outer diameter) of the toilet roll of this invention is 105 to 125 mm. Preferably, the roll diameter of the toilet roll is 110 mm or more. Preferably, the roll diameter of the toilet roll is 120 mm or less. Here, the roll diameter of the toilet roll is the length represented by R in Figure 2. By setting the roll diameter of the toilet roll within the above range, the toilet roll can be installed in any toilet roll holder, and its usage is not limited. Furthermore, by setting the roll diameter of the toilet roll within the above range, portability and storage can be improved.

[0020] The diameter of the paper core (outer diameter of the core) of the toilet roll of the present invention is preferably 35 mm or more, and more preferably 38 mm or more. Furthermore, the diameter of the paper core (outer diameter of the core) of the toilet roll is preferably 45 mm or less, and more preferably 42 mm or less. By setting the diameter of the paper core (outer diameter of the core) of the toilet roll within the above range, the toilet roll can be installed in any toilet roll holder, and its usage is not limited. In addition, by setting the winding diameter of the toilet roll within the above range, portability and storage can be improved.

[0021] The basis weight per ply of toilet paper constituting the toilet roll of the present invention is 11-14 g / m². 2Therefore, 11-13 g / m 2 It is preferable that this is the case. Furthermore, in the case of a toilet roll, it is preferable that both the surface toilet paper 20a and the back toilet paper 20b are within the above range. In the present invention, by setting the basis weight per ply of toilet paper within the above range, it becomes easier to manufacture a toilet roll with a desired roll diameter. Normally, when manufacturing a toilet roll with a long roll length, the roll diameter is controlled by increasing the winding force when winding it into a roll shape. However, in the present invention, it is possible to manufacture a toilet roll with a desired roll diameter without increasing the winding force when winding it into a roll shape to the strength of the conventional method. This also makes it possible to suppress the breakage of the toilet paper during winding. Furthermore, in the present invention, by setting the basis weight per ply of toilet paper within the above range, it is possible to improve water solubility and roll softness.

[0022] The wet tensile strength in the width direction (CD direction) measured by stacking three sets of 2-ply toilet paper that constitute the toilet roll of the present invention is 0.25 to 0.35 N / 15 mm. By adjusting the wet tensile strength in the width direction measured by stacking three sets of 2-ply toilet paper within the above range, it is possible to suppress unintentional tearing when using the 2-ply toilet paper, and in addition, the water-dissolving properties of the toilet paper can be improved. Furthermore, by adjusting the wet tensile strength in the width direction measured by stacking three sets of 2-ply toilet paper within the above range, the softness of the roll itself (roll softness) can be effectively increased.

[0023] The wet tensile strength in the length direction (MD direction), measured by stacking three sets of 2-ply toilet paper constituting the toilet roll of the present invention, is preferably 0.45 N / 15 mm or more and 0.90 N / 15 mm or less. Note that the wet tensile strength in the length direction (MD direction) of toilet paper is greater than the wet tensile strength in the width direction (CD direction), so it will tear in the width direction when wet. On the other hand, by controlling the wet tensile strength in the length direction (MD direction) to a certain extent or more, the strength when wet can be effectively increased.

[0024] Here, the wet tensile strength of toilet paper as used herein is the value obtained by stacking three sets of 2-ply toilet paper (2 plies x 3), cutting it to a width of 15 mm and a span length of 100 mm. For measurement, 0.10 to 0.12 ml of water is evenly impregnated over the entire width of the measurement sample in the longitudinal middle section (mid-length section in the tensile direction), and then the measurement is performed under conditions of a tensile speed of 50 mm / min, and the average of 6 measurements is calculated. For measuring wet tensile strength, for example, a Tensilon universal material tester (manufactured by A&D Co., Ltd.) can be used. The wet tensile strength measurement is performed in an environment compliant with ISO 187 (temperature 23°C ± 1°C, relative humidity 50% ± 2%). More specifically, it is measured in a manner similar to the measurement method described in the examples of wet tensile strength of toilet paper.

[0025] The dry tensile strength in the longitudinal direction of the two-ply toilet paper constituting the toilet roll of the present invention is preferably 1.20 N / 15 mm or more, more preferably 1.30 N / 15 mm or more, even more preferably 1.35 N / 15 mm or more, even more preferably 1.40 N / 15 mm or more, and particularly preferably 1.50 N / 15 mm or more. Furthermore, the dry tensile strength in the longitudinal direction of the two-ply toilet paper is preferably 2.00 N / 15 mm or less, and more preferably 1.95 N / 15 mm or less. By setting the dry tensile strength in the longitudinal direction of the two-ply toilet paper within the above range, unintended breakage during use can be suppressed, and the toilet paper can be wound appropriately. This makes it possible to manufacture a toilet roll with a longer roll length while keeping the roll diameter relatively small. In addition, by setting the dry tensile strength in the longitudinal direction of the two-ply toilet paper within the above range, it becomes unnecessary to add more drying agent than necessary, and the water-soluble properties can be effectively improved.

[0026] The dry tensile strength in the width direction of the two-ply toilet paper constituting the toilet roll of the present invention is preferably 0.50 N / 15 mm or more and 1.20 N / 15 mm or less.

[0027] Here, the dry tensile strength of 2-ply toilet paper as used herein is the average of six measurements taken on a sample of toilet paper cut to a width of 15 mm and a span length of 100 mm, at a tensile speed of 50 mm / min. For measuring dry tensile strength, for example, a Tensilon universal material tester (manufactured by A&D Co., Ltd.) can be used. The dry tensile strength measurement should be performed in an environment compliant with ISO 187 (temperature 23°C ± 1°C, relative humidity 50% ± 2%).

[0028] The toilet paper constituting the toilet roll of the present invention is excellent in terms of strength when wet, but also has excellent water-dissolving properties. Specifically, the water-dissolving time of a single sheet of toilet paper obtained by peeling off the two-ply toilet paper constituting the toilet roll of the present invention is 5 to 16 seconds, preferably 5 to 15 seconds, and more preferably 5 to 12 seconds. By keeping the water-dissolving time of a single sheet of toilet paper obtained by peeling off the two-ply toilet paper within the above range, it is possible to suppress paper blockages in drains and the like. The water-dissolving time of toilet paper in this specification was measured in accordance with JIS P 4501 and is the average value of five measurements.

[0029] The thickness of the two-ply toilet paper constituting the toilet roll of the present invention is preferably 160 μm to 210 μm, and more preferably 175 μm to 210 μm. In this specification, the thickness of the toilet paper refers to the thickness of the two-ply toilet paper pulled from the toilet roll, and is measured in accordance with ISO 13625-3. By setting the thickness of the toilet paper within the above range, it is possible to more effectively enhance water solubility while maintaining practical strength in a wet state.

[0030] The toilet roll of the present invention is preferably embossed toilet paper. That is, it is preferable that the toilet paper is embossed.

[0031] The toilet rolls described above can be manufactured, for example, by adjusting the jet wire ratio during papermaking, adjusting the mixing ratio of softwood pulp and hardwood pulp, and adjusting the freeness of the fiber raw materials. By appropriately controlling the papermaking raw materials and manufacturing conditions, it is possible to achieve both appropriate wet tensile strength and water solubility, and furthermore, roll softness can be realized.

[0032] (Fiber raw materials) The toilet paper constituting the toilet roll of the present invention is obtained by papermaking a slurry containing fiber raw materials. It is preferable to use pulp as the fiber raw material. Examples of pulp include wood pulp, non-wood pulp, and deinked pulp. Examples of wood pulp include hardwood pulp (hardwood kraft pulp (LKP)), softwood pulp (softwood kraft pulp (NKP)), sulfite pulp (SP), dissolved pulp (DP), soda pulp (AP), unbleached kraft pulp (UKP), oxygen-bleached kraft pulp (OKP), and other chemical pulps. Other examples include semi-chemical pulp (SCP), chemiground wood pulp (CGP), and mechanical pulp (GP), such as crushed wood pulp (TMP, BCTMP), but are not particularly limited. Examples of non-wood pulps include, but are not limited to, cotton-based pulps such as cotton linters and cotton lint, non-wood pulps such as hemp, straw, and bagasse, and cellulose, chitin, and chitosan isolated from sea squirts and seaweed. Examples of deinked pulps include, but are not limited to, deinked pulp made from recycled paper. One type of pulp may be used alone, or two or more types may be used in mixture.

[0033] Toilet paper preferably contains pulp derived from coniferous trees and pulp derived from hardwood trees. In this case, the content of coniferous pulp is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, based on the total mass of pulp contained in the toilet paper. Furthermore, the content of coniferous pulp is preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, and particularly preferably 40% by mass or less, based on the total mass of pulp contained in the toilet paper.

[0034] Furthermore, the hardwood pulp content is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, and particularly preferably 60% by mass or more, relative to the total pulp mass contained in the toilet paper. Also, the hardwood pulp content is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, relative to the total pulp mass contained in the toilet paper. By keeping the content of softwood-derived pulp and hardwood-derived pulp within the above ranges, it becomes easy to set the wet tensile strength in the width direction (CD direction) measured by stacking three sets of 2-ply toilet paper within the range of 0.25 to 0.35 N / 15 mm.

[0035] Toilet paper is made by papermaking using the above-mentioned fiber raw materials (papermaking raw materials). The freeness of the fiber raw materials used is preferably 400 ml or more, and more preferably 500 ml or more. Furthermore, a freeness of 700 ml or less is preferable. Freeness is a value expressed in Canadian Standard Clearness (CSF) as specified in JIS P 8121, and is a value that indicates the degree of beating of the fibers. Fiber beating can be carried out on a paper pulp (slurry) in which fibers are dispersed using known beating machines such as beaders and disc refiners. Generally, the smaller the freeness value of the fibers, the stronger the degree of beating, and the greater the damage to the fibers due to beating, and the more fibrillation is progressing. As fibrillation of fibers progresses, the number of bond points between fibers increases, thus improving strength. In other words, in this invention, the freeness can be adjusted as appropriate in order to set the dry tensile strength and wet tensile strength within a preferred range.

[0036] (optional ingredient) The toilet paper constituting the toilet roll of the present invention may contain optional components in addition to the fiber raw material. Examples of optional components include a drying agent, a wetting agent, and a softener. Examples of drying agents include cationized starch, polyacrylamide (PAM), and carboxymethylcellulose (CMC). Examples of wetting agents include polyamide epichlorohydrin, urea, melamine, and thermocrosslinkable polyacrylamide. Examples of softeners include anionic surfactants, nonionic surfactants, and cationic surfactants. The above optional components may be used individually or in combination of two or more.

[0037] Toilet paper does not necessarily need to contain a wet-strength agent, but if it does, the amount of wet-strength agent is preferably 0.01 parts by mass or less, and more preferably 0.005 parts by mass or less, per 100 parts by mass of pulp contained in the toilet paper. By keeping the amount of wet-strength agent within the above range, the amount of wet-strength agent added can be minimized, and the water-soluble properties of the toilet paper can be more effectively enhanced.

[0038] Furthermore, if the toilet paper contains fabric softener, the amount of fabric softener is preferably 0.01 parts by mass or more and 0.50 parts by mass or less per 100 parts by mass of pulp contained in the toilet paper.

[0039] Furthermore, if the toilet paper contains a drying agent, the amount of the drying agent is preferably 0.01 parts by mass or more and 1.00 parts by mass or less per 100 parts by mass of pulp contained in the toilet paper. In order to set the dry tensile strength and wet tensile strength of the toilet paper within a preferred range in the present invention, it is also preferable to appropriately adjust the additive chemicals.

[0040] (Toilet paper manufacturing method) The present invention relates to a method for manufacturing toilet paper rolls, which includes the steps of: making paper from a slurry containing fiber raw materials to obtain a 1-ply toilet paper web; and laminating the 1-ply toilet paper webs (hereinafter also referred to as the lamination step).

[0041] The process of bleaching the fiber raw materials may be included before the process of papermaking the slurry. Known bleaching agents such as oxygen-based bleaches and chlorine-based bleaches can be used in the bleaching process.

[0042] The process of obtaining a 1-ply toilet paper web includes the step of obtaining a slurry containing fiber raw materials. The step of obtaining the slurry preferably includes a step of beating the fiber raw materials. In the beating step, for example, the beating treatment can be carried out using a double disc refiner or the like. During the beating treatment, softwood pulp and hardwood pulp may be beated separately, or they may be beated after being mixed.

[0043] The process of obtaining a 1-ply toilet paper web includes the process of papermaking a slurry containing fiber raw materials. Examples of papermaking machines used in the papermaking process include suction breast formers (cylinder type, elongated type), twin wire formers, cylinder formers (C-wrap, S-wrap), and crescent formers.

[0044] In the papermaking process, a slurry containing fiber raw materials is supplied onto a mesh-like wire to form a thin layer of pulp. Then, as it is transported towards the press section, the water in the pulp layer is removed through the mesh, resulting in dewatering. This process is sometimes called the dewatering process. Generally, the wire consists of a ring of metal or plastic mesh.

[0045] In the papermaking process, the basis weight per ply of toilet paper is 11-14 g / m². 2It is preferable to adjust the ratio of the water flow rate during papermaking to the wire speed (jet-wire ratio (J / W ratio)) so that the wet tensile strength in the transverse direction (CD direction), measured by stacking three sets of 2-ply toilet paper, is 0.25 to 0.35 N / 15 mm. The jet-wire ratio is the ratio of the slurry supply speed to the wire travel speed. When the jet-wire ratio is greater than 1, the slurry supply speed is faster than the wire travel speed, and this is called "push-filling." When the jet-wire ratio is 1 or less, the slurry supply speed is slower than the wire travel speed, and this is called "pull-filling." The jet-wire ratio (J / W ratio) is adjusted, for example, to 0.90 or more and 1.05 or less.

[0046] In the papermaking process, for example, there are two methods: one is to mix softwood pulp and hardwood pulp to form a pulp slurry and then papermake it into a uniform single layer to form wet paper; the other is to combine a softwood pulp layer and a hardwood pulp layer to form a single sheet of wet paper. Either method may be used.

[0047] After the dewatering process, the wet paper is moved from the wire to the felt. Further mechanical water is extracted from the wet paper by applying pressure through the felt to the press rolls. This is sometimes called the pressing or watering process.

[0048] The papermaking process includes a drying process after the dewatering process. The drying process is preferably, for example, a process of blowing hot air onto the wet paper, or a process of pressing the wet paper against the outer surface of a Yankee dryer. In the drying process using a Yankee dryer, it is preferable to perform a crepe treatment in which the dried paper is scraped off the Yankee dryer with a doctor blade to form crepe-like wrinkles. The crepe treatment can impart softness and thickness to the toilet paper web (tissue paper).

[0049] Following the drying process, a base paper winding process is carried out. In the base paper winding process, the toilet paper web (tissue paper) finished through the above process is wound up to obtain a single-ply base paper winding. At this time, it is preferable to wind the toilet paper web (tissue paper) so that the side pressed against the Yankee dryer becomes the outer surface of the base paper winding.

[0050] Two single-ply rolls of the obtained base paper are placed in a winder to form a double-layered laminate. Next, the double-layered laminate is placed in a processing machine, and while unwinding, it is preferable to perform embossing on the surface of the base paper and lamination into two layers. At this time, it is preferable to perform the lamination into two layers so that the sides of the single-ply base paper rolls that were pressed against the Yankee dryer face outwards.

[0051] Embossing is performed by applying pressure with an embossed embossing roll. By changing the amount or pressure of the embossing roll, an embossed shape with a predetermined embossing height can be formed. Embossing may be performed before or after the bonding process, as described later. However, from the viewpoint of improving the tactile feel, it is preferable to perform embossing before the bonding process.

[0052] In the lamination process, two or more single-ply toilet paper webs are stacked and laminated. In this process, for example, after stacking the base paper, a narrow contact emboss is applied to the edges of the product to facilitate lamination. At that time, it is preferable from the standpoint of tactile feel to laminate with the side pressed by the embossing roll facing outwards.

[0053] Following the bonding process, another winding process is included. In this winding process, a predetermined length is wound to satisfy a predetermined product length. The resulting winding is then cut to a predetermined width to obtain a toilet paper product. [Examples]

[0054] The features of the present invention will be further described below with reference to examples and comparative examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following specific examples. In the following, Examples 6 and 7 shall be read as Reference Examples 6 and 7, respectively.

[0055] (Example 1) A pulp slurry was prepared by mixing pulp raw materials to consist of 20% by mass of softwood kraft pulp (NBKP) and 80% by mass of hardwood kraft pulp (LBKP). This slurry was then beaten using a double disc refiner to achieve a freeness of 700 ml. Next, this prepared pulp slurry was paper-made using a twin-wire Yankee machine at a J / W ratio of 0.97 to obtain toilet paper base paper windings. During papermaking, the papermaking conditions were adjusted so that the basis weight per ply of toilet paper was as shown in Table 1. The two resulting rolls of base paper were put through a processing machine, where they were unwound while embossing the surface of the base paper and laminating them into two plies. After that, they were wound again to a predetermined length, and the resulting rolls were cut to a predetermined width to obtain a two-ply toilet roll product.

[0056] (Example 2) A pulp slurry was prepared by mixing pulp raw materials to a ratio of 20% by mass of softwood kraft pulp (NBKP) and 80% by mass of hardwood kraft pulp (LBKP). This slurry was then beaten using a double disc refiner until the freeness reached 600 ml. Next, 0.003 parts by mass of a wet paper strength agent (manufactured by Arakawa Chemical Industries, Ltd., product name: Arafix) was added to 100 parts by mass of the pulp raw materials contained in the toilet paper. The mixture was thoroughly stirred to ensure that all components were uniform, and a pulp slurry was prepared. Two-ply toilet paper was prepared in the same manner as in Example 1, except that the pulp slurry thus obtained was used. The basis weight per ply of the toilet paper was as shown in Table 1.

[0057] (Examples 3 and 4) A pulp slurry was prepared by mixing pulp raw materials to a ratio of 20% by mass of softwood kraft pulp (NBKP) and 80% by mass of hardwood kraft pulp (LBKP). This slurry was then beaten using a double disc refiner until the freeness reached 700 ml. Next, 0.003 parts by mass of a wet paper strength agent (manufactured by Arakawa Chemical Industries, Ltd., product name: Arafix) was added to 100 parts by mass of the pulp raw materials contained in the toilet paper. The mixture was thoroughly stirred to ensure that all components were uniform, and a pulp slurry was prepared. Two-ply toilet paper was prepared in the same manner as in Example 1, except that the pulp slurry thus obtained was used. The basis weight per ply of the toilet paper was as shown in Table 1.

[0058] (Example 5) A pulp slurry was prepared by mixing pulp raw materials to a ratio of 60% by mass of softwood kraft pulp (NBKP) and 40% by mass of hardwood kraft pulp (LBKP). This slurry was then beaten using a double disc refiner until the freeness reached 700 ml. Next, 0.003 parts by mass of a wet paper strength agent (manufactured by Arakawa Chemical Industries, Ltd., product name: Arafix) was added to 100 parts by mass of the pulp raw materials contained in the toilet paper. The mixture was thoroughly stirred to ensure that all components were uniform, and a pulp slurry was prepared. Two-ply toilet paper was prepared in the same manner as in Example 1, except that the pulp slurry thus obtained was used. The basis weight per ply of the toilet paper was as shown in Table 1.

[0059] (Example 6) A pulp slurry was prepared by mixing pulp raw materials to a ratio of 20% by mass of softwood kraft pulp (NBKP) and 80% by mass of hardwood kraft pulp (LBKP). This slurry was then beaten using a double disc refiner until the freeness reached 600 ml. Next, 0.003 parts by mass of a wet paper strength agent (manufactured by Arakawa Chemical Industries, Ltd., product name: Arafix) was added to 100 parts by mass of the pulp raw materials contained in the toilet paper. The mixture was thoroughly stirred to ensure that all components were uniform, and a pulp slurry was prepared. Two-ply toilet paper was prepared in the same manner as in Example 1, except that the pulp slurry thus obtained was used. The basis weight per ply of the toilet paper was as shown in Table 1.

[0060] (Example 7) A pulp slurry was prepared by mixing pulp raw materials to a ratio of 20% by mass of softwood kraft pulp (NBKP) and 80% by mass of hardwood kraft pulp (LBKP). This slurry was then beaten using a double disc refiner until the freeness reached 520 ml. Next, 0.003 parts by mass of a wet paper strength agent (manufactured by Arakawa Chemical Industries, Ltd., product name: Arafix) was added to 100 parts by mass of the pulp raw materials contained in the toilet paper. The mixture was thoroughly stirred to ensure that all components were uniform, and a pulp slurry was prepared. Two-ply toilet paper was prepared in the same manner as in Example 1, except that the pulp slurry thus obtained was used. The basis weight per ply of the toilet paper was as shown in Table 1.

[0061] (Comparative Example 1) Using the pulp slurry obtained in Example 1, the wet tensile strength in the width direction (CD direction) and the basis weight per ply of toilet paper were measured by stacking three sets of 2-ply toilet paper and adjusted to the values ​​shown in Table 2 to obtain a toilet paper base paper winding. The other steps were the same as in Example 1 to obtain a 2-ply toilet roll product.

[0062] (Comparative Example 2) A pulp slurry was prepared by mixing pulp raw materials to a ratio of 60% by mass of softwood kraft pulp (NBKP) and 40% by mass of hardwood kraft pulp (LBKP). This slurry was then beaten using a double disc refiner to achieve a freeness of 380 ml. Next, 0.003 parts by mass of a wet paper strength agent (manufactured by Arakawa Chemical Industries, Ltd., product name: Arafix) was added to 100 parts by mass of the pulp raw materials contained in the toilet paper. The mixture was thoroughly stirred to ensure that all components were uniform, and a pulp slurry was prepared. Two-ply toilet paper was prepared in the same manner as in Example 1, except that the pulp slurry thus obtained was used. The basis weight per sheet of toilet paper was as shown in Table 2.

[0063] (Comparative Example 3) Using the pulp slurry obtained in Example 2, the wet tensile strength in the width direction (CD direction) and the basis weight per ply of toilet paper were measured by stacking three sets of 2-ply toilet paper and adjusted to the values ​​shown in Table 2, thereby obtaining a roll of toilet paper base. The other steps were the same as in Example 1 to obtain a 2-ply toilet roll product.

[0064] (evaluation) (Basic weight) The basis weight of the toilet paper obtained in the examples and comparative examples was measured in accordance with JIS P 8124. Note that the basis weights in Tables 1 and 2 are per ply.

[0065] (Dry tensile strength) The dry tensile strength of the 2-ply toilet paper obtained in the examples and comparative examples was measured using a Tensilon universal material tester (manufactured by A&D Co., Ltd.). For the measurement, a 2-ply toilet paper sample was prepared, set in the tester with a width of 15 mm and a span length of 100 mm between the chucks, and measured at a tensile speed of 50 mm / min. The average of six measurements was calculated to determine the dry tensile strength. The dry tensile strength was measured in an environment compliant with ISO 187 (temperature 23°C ± 1°C, relative humidity 50% ± 2%).

[0066] (Wet tensile strength) The wet tensile strength of three stacks of 2-ply toilet paper obtained in the examples and comparative examples was measured using a Tensilon universal material tester (manufactured by A&D Co., Ltd.). Prior to the measurement, a sample of toilet paper consisting of six layers (three stacks of 2-ply toilet paper) was prepared. In addition, a pair of sponge-equipped tweezers with a total length of 220 mm, each with a sponge measuring 5 mm wide, 30 mm long, and 1 mm thick on each of the clamping parts, was prepared. Felt measuring 5 mm wide, 30 mm long, and 2 mm thick was attached to both sponge parts via double-sided tape, allowing the tweezers to grip objects through the felt. Prior to the measurement, the sample of six stacks of toilet paper was cut to a width of 15 mm and a span length of 100 mm between the chucks. After setting the cut sample in the measuring machine, the pair of scissors of a pair of tweezers were immersed in distilled water to thoroughly and evenly soak both felt surfaces of the tweezers. Using these tweezers, both felt surfaces were pressed against the middle section between the chucks of the sample (the middle section in the tensile direction) to evenly wet the middle section between the chucks of the sample over its entire width, so that the amount of distilled water impregnating the middle section of the sample was 0.10 to 0.12 ml. Subsequently, the wet tensile strength was measured at a tensile speed of 50 mm / min. The average value of six measurements was calculated and used as the wet tensile strength. The wet tensile strength was measured in an environment compliant with ISO 187 (temperature 23°C ± 1°C, relative humidity 50% ± 2%).

[0067] (water decomposable) The water-soluble properties of a single sheet of toilet paper obtained by peeling apart the two-ply toilet paper obtained in the examples and comparative examples were measured in accordance with JIS P 4501. The measurement was performed five times, and the average value was calculated as the water-soluble property.

[0068] (evaluation) <Water solubility during use> The hydrolytic properties obtained in the examples and comparative examples were evaluated based on the measured values ​​of hydrolytic properties obtained in the examples and comparative examples according to the following criteria. ○: Less than 14 seconds △: 14 seconds or more but less than 18 seconds ×: 18 seconds or more

[0069] <Toilet roll softness> The softness of the toilet rolls obtained in the examples and comparative examples was evaluated according to the following evaluation criteria. Specifically, 50 people touched the toilet rolls obtained in the examples and comparative examples and evaluated the softness of the toilet rolls on a three-point scale: 3: excellent, 2: average, 1: poor. The evaluation was based on the average score. ○: 2.5 or higher △: 1.5 or higher, less than 2.5 ×: Less than 1.5

[0070] <Tear resistance in wet conditions> The tear resistance in a wet state during use, as obtained in the examples and comparative examples, was evaluated according to the following evaluation criteria. Specifically, five 10 x 10 cm pieces of toilet paper obtained in the examples and comparative examples were stacked, and 0.5 ml of water was dropped near the center using a dropper. The strength of the sample with the water was then evaluated on a four-point scale when it was rubbed several times against the back of the hand. <Durability when wet> ◎: Particularly excellent ○: Excellent △: Slightly inferior ×: inferior

[0071] [Table 1]

[0072] [Table 2]

[0073] The toilet rolls obtained in the examples possessed all of the following qualities: wet strength, water solubility, and roll softness. On the other hand, the toilet roll obtained in Comparative Example 1 had insufficient wet strength, the toilet roll obtained in Comparative Example 2 had poor water solubility, and the toilet roll obtained in Comparative Example 3 had poor roll softness. [Explanation of symbols]

[0074] 20 toilet paper 20a Toilet paper (front side) 20b Reverse side toilet paper 100 toilet rolls P Cross-sectional area of ​​toilet roll R Toilet roll roll diameter S Core outer diameter

Claims

1. A toilet roll made by winding two-ply toilet paper into a roll, The aforementioned toilet roll has a length of 65 to 105 m and a diameter of 105 to 125 mm. The basis weight per ply of the aforementioned toilet paper is 11 to 13 g / m². ２ And, The wet tensile strength in the width direction (CD direction) measured by stacking three sets of the aforementioned two-ply toilet paper was 0.25 to 0.35 N / 15 mm. A toilet roll in which a single sheet of toilet paper obtained by peeling off the aforementioned two-ply toilet paper has a water-dissolving time of 5 to 16 seconds.

2. The toilet roll according to claim 1, wherein the dry tensile strength in the longitudinal direction (MD direction) of the two-ply toilet paper is 1.20 to 2.00 N / 15 mm.

3. The aforementioned toilet paper contains pulp derived from coniferous trees and pulp derived from hardwoods. The content of the aforementioned coniferous tree-derived pulp is 10 to 70% by mass relative to the total pulp mass. The toilet roll according to claim 1 or 2, wherein the content of pulp derived from hardwoods is 30 to 90% by mass relative to the total pulp mass.

4. The toilet paper is a toilet roll according to any one of claims 1 to 3, wherein the toilet paper is made by papermaking from a fiber raw material having a freeness of 400 ml or more.

5. The toilet roll according to any one of claims 1 to 4, wherein the content of the wet-strengthening agent in the toilet paper is 0.01 parts by mass or less per 100 parts by mass of pulp.

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