Sanitary paper roll package

Abstract

To provide a sanitary paper roll package in which a sanitary paper roll is packaged in a packaging base material mainly made of paper, which has good re-packaging properties.SOLUTION: There is provided a sanitary paper roll package in which multiple sanitary paper rolls are packaged in a packaging base material, in which the packaging base material has a layer structure including a paper base material and a seal layer for sealing the package, a thickness of the packaging base material is 35 μm or more and 80 μm or less, a burst strength of the packaging base material is 105 kPa or more and 190 kPa or less, and a geometric mean breaking elongation in a height direction of the packaging base material parallel to an axial direction of the sanitary paper roll contained in the package and a width direction of the packaging base material perpendicular to the axial direction of the sanitary paper roll contained in the package is 4.11% or more and 6.0% or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sanitary paper roll package in which multiple sanitary paper rolls are packaged in a packaging base material. [Background technology]

[0002] Generally, sanitary paper rolls such as kitchen paper rolls and toilet rolls are sold in multiple units packaged in a packaging base. After opening such packages and removing a portion of the packaged material, there is a demand for repackaging the remaining sanitary paper roll so that it can be stored in a clean environment (Patent Document 1). This demand is particularly pronounced for kitchen paper rolls.

[0003] In recent years, the problem of plastic waste has become more serious worldwide, and there is a desire to replace plastic packaging materials with other materials in order to improve the global environment. In the field of packaging for paper products, a package has been proposed in which the packaging material is replaced from plastic film to a paper-based material, and paper products are wrapped in wrapping paper (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-104449 [Patent Document 2] Patent Publication No. 2021-172415 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the packaging base material is changed from a plastic film to a base material mainly made of paper, it is more difficult to repackage the remaining sanitary paper rolls in the packaging base material after removing some of the multiple sanitary paper rolls contained in the package, compared to when using a film, because paper is thicker and more difficult to bend than film, resulting in inferior storage properties.

[0006] Therefore, an object of the present invention is to provide a sanitary paper roll package in which a sanitary paper roll is packaged in a packaging base material mainly made of paper, which allows for good repackaging of the remaining sanitary paper rolls after some of the multiple sanitary paper rolls contained in the package have been removed. [Means for solving the problem]

[0007] As a result of intensive research to solve the above problems, the inventors have found that the above problems can be solved by a sanitary paper roll package in which multiple sanitary paper rolls are packaged in a packaging base material, the packaging base material having a layer structure including a paper base material and a seal layer for sealing the package, the thickness of the packaging base material being 35 μm to 80 μm, the burst strength of the packaging base material being 105 kPa to 190 kPa, and the geometric mean breaking elongation of the breaking elongation in the height direction of the packaging base material parallel to the axial direction of the sanitary paper roll contained in the package and the breaking elongation in the width direction of the packaging base material perpendicular to the axial direction of the sanitary paper roll contained in the package being 2.9% to 6.0%.

[0008] Specifically, the present invention has the following configuration. [1] A sanitary paper roll package in which multiple sanitary paper rolls are packaged in a packaging base material, The packaging substrate has a layer structure including a paper substrate and a seal layer for sealing the package, The thickness of the packaging substrate is 35 μm or more and 80 μm or less, The burst strength of the packaging substrate is 105 kPa or more and 190 kPa or less, A sanitary paper roll package characterized in that the geometric mean breaking elongation of the packaging substrate in the height direction, which is parallel to the axial direction of the sanitary paper roll contained in the package, and the breaking elongation of the packaging substrate in the width direction, which is perpendicular to the axial direction of the sanitary paper roll contained in the package, is 2.9% or more and 6.0% or less. [2] The sanitary paper roll packaging according to [1], characterized in that the air permeability of the packaging base material is 1000 seconds or more. [3] The sanitary paper roll packaging according to [1] or [2], characterized in that the bending stiffness of the packaging base material in the width direction is 8 μNm or more and 35 μNm or less. [4] A sanitary paper roll package according to any one of [1] to [3], characterized in that the smoothness of the surface of the packaging base material that comes into contact with the sanitary paper roll contained in the package is 100 seconds or more. [5] A sanitary paper roll package according to any one of [1] to [4], characterized in that the transparency of the packaging base material is 60% or more. [6] A sanitary paper roll packaging according to any one of [1] to [5], characterized in that the paper base material is glassine paper. [7] A sanitary paper roll packaging body according to any one of [1] to [6], characterized in that the packaging form of the packaging body is a caramel packaging form. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a sanitary paper roll package in which a sanitary paper roll is packaged in a packaging base material mainly made of paper, which allows for good repackaging of the remaining sanitary paper rolls after some of the multiple sanitary paper rolls contained in the package have been removed. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing a sanitary paper roll packaging according to an embodiment of the present invention. FIG. [Figure 2] 1 is a diagram showing one embodiment of a packaging substrate according to an embodiment of the present invention. [Figure 3] 1A and 1B are diagrams showing another aspect of a packaging substrate according to an embodiment of the present invention. [Figure 4] 10A to 10C are diagrams illustrating an example of the opening and repackaging operations of a sanitary paper roll package. [Figure 5] 10A to 10C are diagrams illustrating another example of the opening and repackaging operation of the sanitary paper roll package. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiments and drawings are provided for illustrative purposes and are not intended to limit the present invention.

[0012] First Embodiment [Hygiene paper roll packaging] 1 is a schematic perspective view of a sanitary paper roll packaging according to a first embodiment of the present invention. In the first embodiment of the present invention, the sanitary paper roll packaging (hereinafter simply referred to as "packaging") 1 includes a plurality of sanitary paper rolls 2 and a packaging base 10 that packages the plurality of sanitary paper rolls 2.

[0013] [Hygiene paper roll] In this specification, a sanitary paper roll refers to a roll-shaped sanitary paper product obtained by winding up a long sanitary paper sheet such as toilet paper, kitchen paper, hand towels, etc. Examples of sanitary paper rolls include, but are not limited to, toilet rolls, kitchen paper rolls, and hand towel rolls.

[0014] The sanitary paper roll may be a single-ply product in which only one sanitary paper sheet is wound into a roll, or a multi-ply product in which two or more sanitary paper sheets are wound together in a roll. Depending on the required quality, the sanitary paper sheet may be embossed to give it a rough surface, perforated to give it perforations for separation, or printed with graphics or letters to add information such as patterns, logos, or messages.

[0015] Sanitary paper sheets are obtained by papermaking a slurry containing a pulp component, which is a fiber raw material. Examples of pulp components include wood pulp, non-wood pulp, and recycled paper pulp. Various chemicals, such as paper strength agents and antifoaming agents, may be added as optional components to achieve the required quality and stabilize operations. Any known papermaking machine can be used for papermaking. During the papermaking process, the sanitary paper sheet may be subjected to creping or other processing. During the papermaking process or any subsequent process, calendaring may be performed.

[0016] 1, the sanitary paper roll 2 is a kitchen paper roll. The packaging substrate 10 wraps two kitchen paper rolls 2 together.

[0017] In the present invention, the number (quantity) of sanitary paper rolls 2 packed in the package 1 may be determined based on the ease of handling of the package 1, product sales strategies, etc., which depend on the dimensions and weight of the sanitary paper rolls 2 and the strength (ease of tearing) of the packaging base material 10. The number of sanitary paper rolls 2 packed in the package 1 is preferably an even number, more preferably four, and even more preferably two.

[0018] [Packaging base material] The packaging substrate 10 according to the embodiment of the present invention includes a paper substrate 100 and a seal layer 110 for sealing the package.

[0019] Figures 2 and 3 are diagrams each showing a non-limiting example of one possible embodiment of the packaging substrate 10 constituting the packaging body 1 shown in Figure 1. In the example shown in Figure 1, the packaging body 1 uses the so-called caramel packaging format, which is known for individual packaging of soft candies such as caramel and for packaging cigarette packets.

[0020] Fig. 2(a) is a schematic development view of the packaging substrate 10, and a plan view of the packaging substrate 10 as seen from the surface (hereinafter also referred to as "front surface") that will be the outer surface of the package 1. Fig. 2(b) is a schematic cross-sectional view taken along line IIb-IIb of the packaging substrate 10 shown in Fig. 2(a), and Fig. 2(c) is a schematic cross-sectional view taken along line IIc-IIc of the packaging substrate 10 shown in Fig. 2(a).

[0021] 2(a), the packaging substrate 10 of this example is rectangular OPQR. A sealant for sealing the packaging body 1 is applied to the hatched area in the drawing.

[0022] 2(b) and 2(c), the sealing agent applied to the paper substrate 100 forms a sealing layer 110, and the packaging substrate 10 has a layer structure including the paper substrate 100 and the sealing layer 110. In this example, the sealing layer 110 entirely covers one side of the paper substrate 100. In the drawings, the thickness and dimensions of each layer are shown schematically and are not drawn to scale.

[0023] FIG. 3 is a diagram showing an example of a possible embodiment of the packaging substrate 10 constituting the packaging body 1 shown in FIG. 1, which is different from the embodiment shown in FIG.

[0024] (a) to (c) of Figure 3 correspond to (a) to (c) of Figure 2, respectively. That is, (a) of Figure 3 is a schematic development view of the packaging substrate 10 and a plan view of the packaging substrate 10 as seen from the surface (surface) that will be the outer surface of the package 1. (b) of Figure 3 is a schematic cross-sectional view of the packaging substrate 10 shown in (a) of Figure 3 taken along line IIIb-IIIb, and (c) of Figure 3 is a schematic cross-sectional view of the packaging substrate 10 shown in (a) of Figure 3 taken along line IIIc-IIIc.

[0025] Fig. 3 differs from Fig. 2 in the region where the sealing layer 110 is provided on the packaging substrate 10. In the embodiment shown in Fig. 3, the sealing layer 110 is provided in the region of the side edge of the packaging substrate 10 indicated by the hatched rectangle OPP1O1, the region of the upper edge of the packaging substrate 10 indicated by the rectangle OO2R2R, and the region of the lower edge of the packaging substrate 10 indicated by the rectangle PP2Q2Q. In addition, the sealing layer 110 is not provided in the region indicated by the rectangle O3P3Q2R2 in the figure.

[0026] 3(b) and 3(c), the packaging substrate 10 has a layer structure including a paper substrate 100 and a sealing layer 110, and the sealing layer 110 partially covers one side of the paper substrate 100. In the drawings, the thickness and dimensions of each layer are shown schematically and are not drawn to scale.

[0027] 2 and 3, in comparison with the packaging body 1 in Fig. 1, the portions of the region indicated by the rectangle OPP1O1 and the portions of the region indicated by the rectangle RQQ1R1 (side edges) (regions indicated by reference numeral 12S in the figures) in the packaging substrate 10 are overlapped and joined via a seal layer 110 provided in the region indicated by the rectangle OPP1O1. Furthermore, the portions of the regions indicated by the rectangles OO2R2R and PP2Q2Q (top and bottom edges) (regions indicated by reference numerals 12T and 12B in the figures) are folded and joined via a seal layer 110 provided in the regions indicated by the rectangles OO2R2R and PP2Q2Q. Therefore, the side edges and top and bottom edges of the packaging substrate 10 described above are the portions that substantially contribute to sealing the packaging body 1.

[0028] Hereinafter, in this specification, the ends (side ends and upper and lower ends) of the packaging substrate 10 that substantially contribute to the sealing of the packaging body 1 as described above will be referred to as the "sealed portion of the packaging body" or the "jointed portion of the packaging substrate" and represented by the symbol 12 (12S, 12T, 12B), and the other portions will be referred to as the "non-sealed portion of the packaging body" or the "non-jointed portion of the packaging substrate" and represented by the symbol N12.

[0029] In the packaging substrate 10 according to an embodiment of the present invention, the area in which the sealing layer 110 is formed is not limited to the examples shown in Figures 2 and 3, and may be formed in any area on the paper substrate 100 as long as it includes the sealing portion 12 of the packaging body.

[0030] [Paper base material] In the embodiment of the present invention, various paper substrates can be used as the paper substrate 100 of the packaging substrate 10 of the packaging body 1.

[0031] The paper base material 100 can be produced by using a pulp component such as wood pulp, non-wood pulp, or recycled paper pulp such as deinked pulp as a main raw material and making paper using a paper machine by a known method.

[0032] Pulp components may be used alone or in combination of two or more types. These pulp components have a significant effect on the quality of the paper base material, so they are appropriately blended in the specified types and proportions to meet the required quality.

[0033] For example, softwood kraft pulp (NKP) and / or hardwood kraft pulp (LKP) may be used in a blending ratio (mass %) of preferably 0-60:100-40, more preferably 20-60:80-40, and even more preferably 40-60:60-40.

[0034] Softwood kraft pulp generally has longer fibers than hardwood kraft pulp. Therefore, the higher the content of softwood kraft pulp in the pulp raw material, the stronger the paper strength of the resulting paper base material 100. For example, the tensile strength in the MD direction (also called the papermaking direction or the machine direction (T direction)) increases, resulting in a paper base material 100 that is less likely to tear even when force is applied in the MD direction.

[0035] The paper substrate 100 applicable to the packaging substrate 10 of the packaging body 1 may be determined based on factors such as processing suitability (ease of bending, rigidity, printability) when manufacturing the packaging body 1, strength (ease of tearing) and appearance (transparency, whiteness) when made into the packaging body 1, and repackaging ability of the packaging body 1 after opening the packaging body 1.

[0036] To achieve the required quality and stabilize production operations, various commonly used chemicals may be added as optional components to the paper base material 100. Examples of optional components include dry strength agents, wet strength agents, sizing agents, bulking agents, dyes, fragrances, dispersants, drainage aids, pitch control agents, and retention aids.

[0037] Specific examples of the paper substrate 100 that can be suitably applied to the embodiment of the present invention include, but are not limited to, transparent paper such as glassine paper and one-sided glossy paper such as pure white paper.

[0038] [Glassine paper] Glassine paper is a transparent tissue paper made by passing base paper made from highly beaten chemical pulp through a calender to apply heat and pressure to eliminate the gaps between the fibers. Glassine paper has properties such as high smoothness, gloss, high density, high air permeability (i.e., it takes a long time for a certain amount of air to pass through a certain area of ​​the paper under a certain pressure; in other words, it has low air permeability), and translucency.

[0039] Generally, "transparent" means being able to see through to the other side of an object or what is inside, while "semi-transparent" means having a low degree of transparency, being somewhere between transparent and opaque, or being able to see the color, light, and shade of an object while not being able to see the shape of the object on the other side clearly. "Opaque" means being unable to see through something to the other side. In this specification, "transparent" and "semi-transparent" are collectively referred to as simply "transparent."

[0040] "Transparency" refers to the rate at which light passes through paper, expressed as a percentage of the amount of incident light. The higher the transparency value, the more clearly you can see through it to the other side or inside.

[0041] In one preferred embodiment of the present invention, in the example of Figure 1, glassine paper is used for the paper substrate 100 of the packaging substrate 10, and the sanitary paper roll 2 (two kitchen paper rolls), which is the object to be packaged in the package 1, can be seen through the packaging substrate 10.

[0042] From the viewpoint of visibility of the sanitary paper roll 2, which is the packaged item, from outside the package 1, in one preferred embodiment of the present invention, the transparency of the packaging substrate 10 is 60% or more, preferably 65% ​​or more, more preferably 70% or more, and even more preferably 75% or more. When the transparency of the packaging substrate 10 is 60% or more, it is easy to check the condition of the packaged items 2 contained in the package 1 (for example, the type, quantity, color, pattern, and shape (presence or absence of printing or embossing, etc.) of the packaged items 2).

[0043] One way to achieve such transparency in the packaging substrate 10 is to employ a highly transparent paper substrate 100. In one preferred embodiment of the present invention, the transparency of the paper substrate 100 is 60% or more, preferably 65% ​​or more, more preferably 70% or more, and even more preferably 75% or more. Examples of highly transparent paper that can be used for the paper substrate 100 include, but are not limited to, glassine paper and parchment paper.

[0044] The transparency of the paper substrate 100 and the packaging substrate 10 can be measured in accordance with ISO 5-2 using a diffuse light transmittance meter DOT-5 (manufactured by Murakami Color Research Laboratory Co., Ltd.) The transparency of the packaging substrate 10 is measured in the region of the non-jointed portion N12 of the packaging substrate 10 (the non-sealed portion of the package 1).

[0045] [Effects of the embodiment using glassine paper] In this embodiment, by using glassine paper as the paper base material 100 of the packaging base material 10, the following effects can be achieved, for example. (1) Because glassine paper is transparent, the sanitary paper rolls 2 contained in the package 1 can be easily seen through the transparent glassine paper 100 (and the transparent seal layer 110 provided on top of it, if present) in the non-sealed portion N12 of the package 1 (internal visibility is possible). For example, the type, quantity, color, pattern, shape (e.g., whether or not there is printing or embossing) of the sanitary paper rolls 2 can be confirmed from the outside of the package 1 (see Figure 1). (2) Because glassine paper has high air permeability, the sanitary paper roll 2, which is the object to be packaged in the packaging base material 10, is less susceptible to the effects of external moisture, odors, and the like.

[0046] [Parchment paper] "Parchment paper" is a transparent paper in which some of the cellulose fibers in the base paper have been converted into amorphous amyloids, and can be obtained by treating base paper, which is primarily composed of cellulose fibers, with an acid such as sulfuric acid, hydrochloric acid, formic acid, or acetic acid. For example, parchment paper can be produced by a series of processes: immersing the base paper in sulfuric acid, neutralizing and / or washing with water repeatedly, and then drying. The immersion time cannot be generally limited, but can be adjusted appropriately taking into account the thickness, density, sizing degree, washing ability, drying ability, etc. of the base paper.

[0047] When base paper, which is made up of cellulose pulp fibers, is immersed in sulfuric acid, the cellulose swells, hydrolyzes, and dissolves. The dissolved cellulose becomes a viscous, translucent, gelatinous substance that coats the surface of the base paper, firmly binds the fibers together, and fills the pores and gaps in the paper layers, forming an extremely dense paper layer structure. As a result, diffuse reflection of light within the paper layers is reduced, promoting transparency.

[0048] The gelatinous substance produced by the hydrolysis of cellulose is neutralized and / or washed with water to stop the hydrolysis reaction and become hydrated cellulose. Therefore, the pores in the paper are blocked by cellulose, which is chemically the same as the base paper, improving transparency and reducing minute white spots that are thought to be caused by the formation or pores in the base paper layer, resulting in base paper with a uniform transparency.

[0049] It is also possible to produce paper with higher transparency by incorporating fine fibrous cellulose with an average fiber width of 2 to 50 nm, which can be obtained by chemically treating or defibrating lignocellulosic raw materials into the pulp used.

[0050] [Effects of the embodiment using parchment paper] Using parchment paper as the paper substrate 100 of the packaging substrate 10 can provide an internal visibility effect, similar to the use of glassine paper. That is, in terms of the exterior of the package 1, the sanitary paper rolls 2 packaged in the package 1 can be easily seen through the transparent parchment paper 100 in the unsealed portion of the package 1 (and the transparent seal layer 110 provided thereon, if present). For example, the type, quantity, color, pattern, shape (e.g., whether or not embossed) of the sanitary paper rolls 2 can be confirmed from the outside of the package 1 (see FIG. 1).

[0051] [One-glazed paper] In one aspect of this embodiment, the paper substrate 100 may be one-sided glossy paper. One-sided glossy paper is paper with one side that is made glossy by increasing the smoothness of the other side, and has a glossy side (high smoothness side) that is relatively smooth and feels slippery to the touch, and a non-glossy side (low smoothness side) that is relatively less smooth and feels rough to the touch.

[0052] One-sided glazed paper can be produced by making paper from pulp raw materials in a papermaking machine equipped with a mirror-finished Yankee dryer, and then pressing a wet paper web against the mirror-finished surface of the Yankee dryer to dry it. The smoothness and gloss of the surface that comes into contact with the Yankee dryer are higher than those of the surface that does not come into contact with the Yankee dryer, and in this way a paper base material (one-sided glazed paper) 100 having a glossy side and a non-glossy side can be produced.

[0053] For example, glassine paper is made by passing base paper made from highly beaten chemical pulp through a calender to apply heat and pressure to eliminate the gaps between the fibers, resulting in high density and smoothness, while single-sided glazed paper is made by pressing a wet paper onto the surface of a mirror-finished Yankee dryer and drying it, thereby improving the smoothness of the surface that comes into contact with the Yankee dryer.Since single-sided glazed paper is not calendered or the calendering conditions are mild, the inter-fiber bonds of the pulp fibers contained in the base paper are relatively hard to break, making it possible to obtain paper with the same strength as glassine paper at a relatively low cost.

[0054] [Pure blank paper] In one aspect of the embodiment of the present invention, the paper substrate 100 may be pure white paper. Pure white paper is a type of the single-sided gloss paper described above, and is produced using pulp with high whiteness, such as bleached pulp, and has high whiteness.

[0055] [Whiteness] The whiteness of pure white paper is, for example, 80% or more, and for example, 90% or more. The whiteness can be measured in accordance with JIS P8148:2005 (ISO2470).

[0056] [Effects of using pure white paper] In the case of using pure white paper for the paper base material 100, in addition to the effects described above in the section on one-sided glossy paper, its high whiteness results in a high-quality appearance, and when printing is applied to the packaging base material 10, the background of the print becomes white, which has the effect of improving the visibility of the print.

[0057] [Sealing layer] The sealing layer 110 is a layer containing a sealing agent.

[0058] [Sealant] As a sealing agent applicable to the embodiment of the present invention, any sealing agent known in the art that can bond the packaging substrate 10 and seal the package 1 can be used. As the sealing agent, any material that exhibits heat sealing properties, i.e., a heat sealing agent, or any material that exhibits adhesive properties other than a heat sealing agent, i.e., an adhesive, can be used.

[0059] Examples of heat-sealing agents that can be used include polyolefin resins and other thermoplastic resins, with polyethylene resins being preferred. Examples of such materials include low-density polyethylene, linear low-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-ethyl acrylate copolymers, ethylene-methyl acrylate copolymers, ethylene-methacrylic acid copolymers, ionomers, amorphous polyesters, polypropylene, styrene-acrylic copolymers, propylene-ethylene copolymers (preferably copolymers with an ethylene content of 10 mol% or less), polypropylene resins obtained by graft-polymerizing or copolymerizing polypropylene with unsaturated carboxylic acids, unsaturated carboxylic anhydrides, ester monomers, and the like, medium-density polyethylene, and high-density polyethylene. These materials may be used alone or in combination of two or more.

[0060] Examples of adhesives include water-soluble polymers such as methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol, and the like, as well as derivatives and mixtures thereof.

[0061] [Method for forming the sealing layer] The sealing layer 110 can be formed by using, for example, a commonly used method such as the following. (1) A method of forming a film on a paper substrate 100 by extrusion of a thermoplastic resin such as a polyolefin resin or a composition containing a thermoplastic resin. (2) A method of laminating a film made of a thermoplastic resin or a film containing a thermoplastic resin to the paper substrate 100 using a known heat sealing processing device (laminating processing device). (3) A method of applying a water-based heat-sealing agent in which a thermoplastic resin or a thermoplastic resin composition is dissolved or dispersed in water, or a solvent-based heat-sealing agent in which a thermoplastic resin or a thermoplastic resin composition is dissolved or dispersed in a solvent, a water-soluble polymer, its derivative or a mixture thereof, onto a paper substrate 100 by a known method such as roll coating, gravure roll coating or kiss coating.

[0062] By forming the seal layer 110 on the paper substrate 100 in the manner described above, the packaging substrate 10 according to the embodiment of the present invention is obtained.

[0063] [Example of packaging manufacturing method] 1 and 2, a description will be given of non-limiting examples of packaging formats applicable to the packaging body 1 according to the first embodiment and a method for manufacturing the packaging body 1. Note that even when the packaging base material 10 shown in Fig. 3 is used instead of the packaging base material 10 shown in Fig. 2, the packaging body 1 can be manufactured by a similar method.

[0064] The package 1 shown in FIG. 1 is a so-called caramel package type package, and can be manufactured, for example, through the steps described below.

[0065] (Step 1) A step of preparing a rectangular OPQR packaging substrate 10, as shown in FIG. 2, in which a sealing agent for sealing the packaging body 1 is applied to a predetermined area of ​​the packaging substrate 10 (the area indicated by hatching in the figure) to form a sealing layer 110.

[0066] 2, the MD direction (longitudinal direction) of the packaging substrate 10, and therefore the MD direction (longitudinal direction) of the paper substrate 100, is aligned with the A direction in the figure, but in this embodiment, the direction in which the packaging substrate 10 (paper substrate 100) is used is not limited to this. The direction in which the packaging substrate 10 (paper substrate 100) is used may be determined according to the direction resulting from the fiber orientation of the paper, from the viewpoints of processability when manufacturing the packaging body 1, repackaging after opening (ease of bending, strength against bending), posture and strength (ease of tearing) of the completed packaging body 1, and other desired properties.

[0067] (Step 2) A step of arranging the sanitary paper rolls (two kitchen paper rolls) 2 to be packaged so that they face the back surface of the packaging substrate 10 (the surface that will become the inner surface of the package 1) and so that the axial direction of the rolls coincides with the direction A indicated by arrow A in the figure.

[0068] (Step 3) The item to be packaged 2 is wrapped around the packaging substrate 10 so that the surface of the packaging substrate 10 (the surface that will become the outer surface of the packaging body 1) is facing outward, and both side end portions 12S of the packaging substrate 10 (the side end areas of the packaging substrate 10 indicated by the rectangle OPP1O1 and the side end areas of the packaging substrate 10 indicated by the rectangle RQQ1R1) are overlapped to package the item into a cylindrical shape.

[0069] In step 3, both side edges 12S of the packaging substrate 10 are joined and sealed via the seal layer 110 provided on the surface of the paper substrate 100 so that the front and back surfaces of the paper substrate 100 are in contact with each other.

[0070] Hereinafter, in this specification, this joining method of joining different surfaces (front and back surfaces) of the paper base material 100 together by bringing them into contact with each other will also be referred to as "overlap joining."

[0071] (Step 4) Next, at each of the opening ends (top and bottom ends) 12T, 12B of the cylindrical packaging formed in step 3, the portions of the packaging base material 10 that protrude from the circumferential surface of the sanitary paper roll 2 are folded toward each other to form two pairs of opposing flap-like portions, which are then joined along the end surfaces of the sanitary paper roll 2 to enclose the sanitary paper roll 2.

[0072] 2(a), the region of the upper end 12T of the packaging substrate 10 indicated by the rectangle OO2R2R and the region of the lower end 12B of the packaging substrate 10 indicated by the rectangle P2PQQ2 are folded along the mountain fold line UFL (dashed line) and the valley fold line DFL (dotted line) in the figure to form flap-like portions. The flap-like portions are joined via the seal layer 110 provided on the surface of the paper substrate 100, thereby obtaining the package 1 shown in FIG.

[0073] In this way, the upper and lower end portions 12T, 12B of the packaging substrate 10 are sealed by bonding the surfaces of the paper substrates 100 together via the respective sealing layers 110. Hereinafter, in this specification, this bonding method of bonding the same surfaces of the paper substrates 100 together by bonding them together will also be referred to as "hand-to-hand bonding."

[0074] In this specification, the "upper and lower ends" of the packaging substrate 10 and the "upper and lower ends" of the "upper and lower end surfaces" of the packaging body 1 refer to both ends in the direction A indicated by the arrow A in the drawings, and the "(both) side ends" of the packaging substrate 10 refer to (both) ends of the wound packaging substrate 10 in a direction intersecting the direction A, such as the direction B indicated by the arrow B in Figure 2. In addition, in this specification, the direction A indicated by the arrow A in the drawings is also referred to as the "height direction," and the direction B indicated by the arrow B in the drawings is also referred to as the "width direction."

[0075] Through the above steps, in this embodiment employing the caramel packaging format, the sealing layer 110 is provided on the outer surface (front surface) of the packaging body 1, and both overlap sealing and hem sealing are performed. As a result, the packaging body 1 is sealed by a sealing part 12 having a sealing part 12S where both side edges of the packaging substrate 10 are overlapped and joined so that the front and back surfaces of the paper substrate 100 face each other, and sealing parts 12T and 12B where the upper and lower edges of the packaging substrate 10 are folded and joined so that mainly the surfaces face each other.

[0076] In the manufacturing process exemplified above, the packaging substrate 10 is prepared in advance and cut into a rectangular shape of a predetermined size in plan view, and one packaging body 1 is manufactured, but the manufacturing method of the packaging body 1 is not limited to this. For example, the packaging substrate 10 may be prepared in the form of a long continuous sheet, and in a subsequent step, the packaging substrate 10 may be cut at the same time as or after the sanitary paper roll 2 is placed on the packaging substrate 10, thereby manufacturing the packaging body 1.

[0077] In an embodiment of the present invention, the overlapping ends of the packaging substrate 10 at the sealing portion 12 (12S, 12T, 12B) are joined together by a sealing agent contained in the seal layer 110 of the packaging substrate 10. When the sealing agent is a heat sealing agent, the joining is performed by heat sealing (thermal fusion), and when the sealing agent is an adhesive, the joining is performed by adhesion.

[0078] When the sealing agent is a heat-sealing agent, a known heat sealer can be used to heat-seal the heat-seal layer 110. During the heat-sealing process, heat and pressure are applied to the area of ​​the sealing portion 12 (12S, 12T, 12B) where the packaging substrate 10 is superimposed, causing the heat-sealing agent of the heat-seal layer 110 in that area to soften and melt. Phenomena such as microscopic penetration of the softened heat-sealing agent and mixing and integration of the melted heat-sealing agent occur, and after cooling, the sealing portion 12 (12S, 12T, 12B) to which the heat-sealing layer 110 is firmly bonded is obtained.

[0079] When the sealing agent is an adhesive, a certain amount of time is required for the adhesive to dry, but when the sealing agent is a heat sealing agent, it is preferable in that there is no need to consider the drying time.

[0080] [Opening and repackaging / repackability] The opening and repackaging operations of the package 1 and the repackaging properties will be described with reference to FIGS.

[0081] (Opening and repackaging) FIG. 4 is a schematic diagram illustrating an example of the opening and repackaging operation of the package 1. In FIG.

[0082] FIG. 4(1) shows the package 1 before opening.

[0083] 4(2) shows an example of the opening operation of the package 1. In this example, the package 1 is opened by peeling off the bond of the packaging base material 10 at the sealed portion 12 of the package 1.

[0084] First, the sealing layer 110 that bonds the packaging substrate 10 is peeled off at the sealed portion 12 of the package 1 (the joint portion of the packaging substrate 10) so that it is sufficient to remove the sanitary paper roll 2. At this time, the joints at the top end, side end, and bottom end 12 (12T, 12S, 12B) of the packaging substrate 10 may be peeled off entirely or partially.

[0085] Next, one of the multiple sanitary paper rolls 2 contained in the package 1 (in this example, one of the two kitchen paper rolls) is removed from the package 1.

[0086] FIG. 4(3) shows an example of the package 1 after repackaging.

[0087] First, in Figure 4 (2), the remaining sanitary paper roll 2 is rewound in the packaging substrate 10 to eliminate the space inside the package 1 created by removing the sanitary paper roll 2. Next, the upper and lower end portions 12 (12T, 12B) of the packaging substrate 10 are folded along the end faces of the sanitary paper roll 2 to close the opening of the package 1. In this way, the packaged item (sanitary paper roll) 2 is repackaged. Repackaging is performed so that the sanitary paper roll 2 contained inside the package 1 repackaged in the packaging substrate 10 is not exposed, to ensure good storage stability of the sanitary paper roll 2. In this way, a repackaged package 1 is obtained, as shown in Figure 4 (3).

[0088] FIG. 5 is a schematic diagram illustrating another example of the opening and repackaging operation of the package 1. In FIG.

[0089] In the example of Figure 5, (1) of Figure 5 shows the packaging body 1 before opening, (2) of Figure 5 shows an example of the opening operation of the packaging body 1, and (3) of Figure 5 shows an example of repackaging the packaging body 1.

[0090] The example of Fig. 5 differs from the example of Fig. 4 in that, as shown in Fig. 5(2), the package 1 is opened by tearing the packaging base material 10 mainly at the non-sealed portion N12 of the package 1. The repackaging operation of the example of Fig. 5 is performed in almost the same way as the example of Fig. 4, and therefore a redundant explanation will be omitted.

[0091] Thus, in an embodiment of the present invention, opening of the packaging body 1 may be performed by peeling off the bond at the sealed portion 12, or by breaking the packaging substrate 10 mainly in the area of ​​the non-sealed portion N12, or by a combination of peeling off the bond at the sealed portion 12 and breaking the packaging substrate 10 mainly in the area of ​​the non-sealed portion N12.

[0092] In either case, for good storage stability, it is preferable that the sanitary paper roll 2 be repackaged so that the sanitary paper roll 2 contained therein is not exposed from the package 1 repackaged with the packaging base material 10.

[0093] (Repackability) The packaging substrate 10, which is primarily made of paper, is generally thicker and more difficult to bend than conventional film packaging substrates. As a result, when repackaging, it tends to be difficult to remove some of the multiple sanitary paper rolls 2 contained in the package 1 and then repackage them with the packaging substrate 10 without exposing the remaining sanitary paper rolls 2.

[0094] Furthermore, even if the remaining sanitary paper roll 2 can be temporarily repackaged in the packaging base material 10 so that it is not exposed, the package 1 may open naturally over time after repackaging, exposing the packaged item 2. This exposure results in poor storage properties.

[0095] In response to this problem, the present invention aims to provide a sanitary paper roll package in which a sanitary paper roll is packaged in a packaging base material mainly made of paper, which allows for good repackaging of the remaining sanitary paper rolls after some of the multiple sanitary paper rolls contained in the package have been removed.

[0096] In this specification, the term "repackaging property" refers to the ease with which the packaged item 2 can be repackaged with the packaging substrate 10 after the package 1 has been opened. The ease of repackaging includes the ease with which the packaging substrate 10 can bend (processability) and the difficulty with which the package can be opened over time after repackaging.

[0097] As a result of intensive research to solve the above-mentioned problems, the inventors have found that if one simply tries to reduce the thickness of the packaging substrate 10 to improve repackaging, the basis weight of the packaging substrate 10 also decreases, and as the basis weight decreases, the packaging substrate 10 becomes more prone to tearing, and that the above-mentioned problems can be solved by controlling the thickness of the packaging substrate 10, the burst strength of the packaging substrate 10, and the geometric mean breaking elongation of the packaging substrate 10 within predetermined ranges.

[0098] [Basic weight] In this specification, the basis weight of the packaging substrate 10 and the basis weight of the paper substrate 100 are the basis weights per sheet (g / m ) measured in accordance with JIS P8124. 2 ) The basis weight of the sealing layer 110 can be calculated by subtracting the basis weight of the paper substrate 100 from the basis weight of the packaging substrate 10 in the area where the sealing layer 110 is provided. The basis weight of the packaging substrate 10 is measured in the non-sealed portion N12 of the package 1 (the non-jointed portion of the packaging substrate 10).

[0099] [Basis weight of packaging substrate] In an embodiment of the present invention, the basis weight of the packaging substrate 10 is, for example, 39 g / m 2 More than 65g / m 2 Preferably, it is 45 g / m or less. 2 More than 60g / m 2 More preferably, it is:

[0100] When the basis weight of the packaging substrate 10 is low, the basis weight of the paper substrate 100 contained in the packaging substrate 10 is generally low, the constituent pulp fibers are few, the inter-fiber bonds are few, and the strength tends to be low and easy to tear. Therefore, from the viewpoint of the tear resistance of the packaging substrate 10, it is preferable that the basis weight of the packaging substrate 10 is high.

[0101] On the other hand, when the basis weight of the packaging substrate 10 is high, the paper thickness or density generally increases, and the flexibility and softness of the packaging substrate 10 decreases, making the packaging substrate 10 less flexible during the manufacture or repackaging of the packaging body 1, which tends to reduce the processing suitability and repackaging ability during the manufacture of the packaging body 1.

[0102] Furthermore, if the seal layer is a heat seal layer, heat transfer during the heat sealing process may be insufficient due to an increase in paper thickness, resulting in a decrease in the heating temperature of the heat seal layer and making it impossible to obtain a satisfactory bond strength. Therefore, from the viewpoints of the processability and repackaging properties of the package 1 and the heat sealability (adhesion) of the sealed portion 12 of the package 1, it is preferable that the basis weight of the packaging substrate 10 be low.

[0103] When the basis weight of the packaging substrate 10 is within the above range, the packaging substrate 10 has adequate strength and is not easily torn, and the processability during the production of the package 1 and the heat sealability at the sealing portion 12 can be ensured.

[0104] [Seal layer basis weight] In an embodiment of the present invention, the basis weight of the sealing layer 110 is, for example, 5 g / m 2 More than 25g / m 2 In the case of a seal layer formed by extruding a thermoplastic resin or a composition containing a thermoplastic resin onto a paper substrate, and a seal layer formed by laminating a film made of a thermoplastic resin or a film containing a thermoplastic resin using a lamination processing device, the basis weight of the seal layer 110 is preferably 10 g / m or less. 2 More than 20g / m 2 In addition, when a heat sealing agent or adhesive is applied to a paper substrate, the basis weight of the sealing layer 110 is preferably 5 g / m or less. 2 More than 10g / m 2 More preferably, it is:

[0105] When the basis weight of the sealing layer 110 is low, the thickness (amount) of the sealing layer (adhesive or heat sealing agent) that can be involved in bonding between the packaging substrates 10 to be joined is generally thin (small), and good adhesion (sealability) may not be obtained at the sealing portion 12.

[0106] Furthermore, as the basis weight of the sealing layer 110 increases, the sealing layer 110 generally becomes thicker. When the sealing layer 110 is a heat-sealing layer, if the sealing layer 110 becomes thicker, heat transfer may become insufficient during the heat-sealing process. In this case, it becomes difficult to obtain anchoring effects such as melting, fusion, and penetration of the heat-sealing agent into recesses, and good bonding strength may not be obtained, resulting in poor sealing properties.

[0107] When the basis weight of the sealing layer 110 is within the above range, the adhesiveness and heat sealability of the sealing portion 12 can be ensured.

[0108] [Packaging substrate thickness (paper thickness)] In an embodiment of the present invention, the thickness (paper thickness) 10th of the packaging substrate 10 is 35 μm or more and 80 μm or less, preferably 40 μm or more and 75 μm or less, and more preferably 45 μm or more and 65 μm or less.

[0109] The thickness of the packaging substrate (paper thickness) can be measured in accordance with ISO534:2011. The pressure on the pressurized surface during measurement is 100 kPa ± 10 kPa. The measurement is performed on the area of ​​the non-sealed portion N12 of the package 1, avoiding the sealed portion 12.

[0110] As described above, referring to Figures 1 and 2 or 3, the packaging substrate 10 has a sealed portion (jointed portion of the packaging substrate 10) 12 (12S, 12T, 12B) of the packaging body 1, which is the area where the ends of the packaging substrate 10 are overlapped and joined by the sealing layer 110 at the end, thereby sealing the packaging body 1, and a non-sealed portion (non-jointed portion of the packaging substrate 10) N12 of the packaging body 1, which is the other area.

[0111] The thickness 10th of the packaging substrate 10 is the thickness measured at the unsealed portion N12 of the packaging body 1 (the unjoined portion of the packaging substrate 10). In the packaging body 1 shown in FIG. 1, the thickness of the packaging substrate 10 is measured in a region of the packaging substrate 10 that forms the side of the packaging body 1 and that does not contribute to sealing the packaging body 1, and that is wound in the circumferential direction of the sanitary paper roll 2 (direction B, perpendicular to direction A, indicated by arrow A, which is the axial direction). This measurement region corresponds to the region indicated by the rectangle O3P3Q3R3 in the schematic development views of the packaging substrate 10 in FIGS. 2 and 3.

[0112] 2, in a configuration in which the sealing layer 110 is provided on the entire surface of the packaging substrate 10 and the non-sealing portion (non-joining portion) N12 includes the sealing layer 110, the thickness 10th of the packaging substrate 10 is the thickness including the paper substrate 100 and the sealing layer 110. Also, in a configuration in which the sealing layer 110 is provided on the sealing portion (joining portion of the packaging substrate 10) 12 of the packaging body 1 but the non-sealing portion (non-joining portion of the packaging substrate 10) N12 of the packaging body 1 does not include the sealing layer 110, the thickness 10th of the packaging substrate 10 is the thickness including the paper substrate 100 but excluding the sealing layer 110.

[0113] Hereinafter, in this embodiment, physical properties of the packaging substrate 10, such as thickness, burst strength, breaking elongation, air permeability, bending stiffness, smoothness, and transparency, are measured in the unsealed portion (unjoined portion of the packaging substrate 10) N12 of the package 1. Furthermore, each physical property of the packaging substrate 10 is measured under the same humidity conditioning conditions as the sample humidity conditioning conditions, after conditioning the sample according to JIS P8111.

[0114] When the thickness 10th of the packaging substrate 10 is thin, the basis weight of the packaging substrate 10 also tends to be small. As the basis weight decreases, the packaging substrate 10 becomes more prone to tearing.

[0115] If the thickness 10th of the packaging substrate 10 is large, the packaging substrate 10 will be difficult to bend when repackaging the remaining sanitary paper rolls 2 after removing some of the multiple sanitary paper rolls 2 contained in the packaging body 1, and the packaging body 1 will be easily opened naturally over time after repackaging, resulting in poor repackaging properties.

[0116] When the thickness of the packaging substrate 10 is 35 μm or more and 80 μm or less, the packaging substrate 10 is difficult to tear and easy to bend, and the package 1 is difficult to open naturally over time after repackaging, resulting in good repackaging properties.

[0117] [Density of packaging substrate] In an embodiment of the present invention, the density of the packaging substrate 10 is preferably 0.850 g / cm 3 More than 1.200g / cm 3 or less, more preferably 0.900 g / cm 3 More than 1.150g / cm 3 The following is the result.

[0118] The density of the packaging substrate is a calculated value obtained from the basis weight of the packaging substrate obtained by the above measurement method and the thickness (paper thickness) of the packaging substrate, and can be calculated by the formula "(basis weight of packaging substrate) ÷ (thickness (paper thickness) of packaging substrate)" (unit: g / cm 3 ).

[0119] In the range of basis weight of the packaging substrate defined in the above-described embodiment of the present invention, the density of the packaging substrate 10 is 0.850 g / cm 3 If the density is smaller than 1.200 g / cm3, the packaging substrate 10 contains fewer fibers, and therefore the inter-fiber bonding is less, making the packaging substrate 10 more likely to tear. 3 If it is larger, the packaging base material 10 is difficult to bend, and the processability during the production of the package 1 and the ease of repackaging after opening are deteriorated.

[0120] [Burst strength of packaging substrate] In an embodiment of the present invention, the burst strength of the packaging substrate 10 is 105 kPa or more and 190 kPa or less, preferably 105 kPa or more and 175 kPa or less, and more preferably 110 kPa or more and 170 kPa or less. As described above, the burst strength of the packaging substrate 10 is measured at the unsealed portion N12 of the package 1 (the unjoined portion of the packaging substrate 10).

[0121] The burst strength of the packaging substrate 10 can be measured in accordance with JIS P8112:2008.

[0122] If the bursting strength of the packaging substrate 10 is low, the packaging substrate 10 is likely to break due to pressure applied by the fingertips when the package 1 is picked up. If the bursting strength of the packaging substrate 10 is high, the packaging substrate 10 is difficult to bend, and the package 1 is likely to open naturally over time after repackaging, resulting in poor repackaging properties.

[0123] When the burst strength of the packaging substrate 10 is 105 kPa or more and 190 kPa or less, the packaging substrate 10 is less likely to break when the package 1 is picked up and is easy to bend, and the package 1 is less likely to open naturally over time after repackaging, resulting in good repackaging properties.

[0124] The burst strength of the packaging substrate can be adjusted by changing one or a combination of two or more of the following conditions during the papermaking process: (1) adjusting the blend of softwood pulp and hardwood pulp, (2) adjusting the freeness, (3) adjusting the J / W ratio, and (4) selecting or changing the type and amount of dry strength improver used in the paper base material 100; and (5) the type of sealing agent used in the sealing layer and (6) the basis weight of the sealing layer during the manufacture of the packaging substrate 10. Here, the J / W ratio is the ratio of the jet velocity (J), which is the ejection speed of the pulp dispersion in the papermaking machine when making the paper base material, to the wire speed (W), and is also called the jet-wire ratio.

[0125] [Geometric mean breaking elongation of packaging substrate] In an embodiment of the present invention, the geometric mean elongation at break GE of the packaging substrate 10 is 2.9% or more and 6.0% or less, more preferably 3.0% or more and 5.5% or less, and even more preferably 3.0% or more and 5.0% or less.

[0126] If the geometric mean elongation at break of the packaging substrate 10 is small, the packaging substrate 10 is likely to tear at the area where finger pressure is applied and in the vicinity thereof when the packaging body 1 is picked up. If the geometric mean elongation at break of the packaging substrate 10 is large, the elongation creates slack when opening the packaging body 1, making it difficult to tear and open the packaging substrate 10. If the geometric mean elongation at break of the packaging substrate 10 is 2.9% or more and 6.0% or less, the packaging substrate 10 is unlikely to tear when the packaging body 1 is picked up and the packaging body 1 is easy to open.

[0127] The geometric mean breaking elongation GE of the packaging substrate 10 is the geometric mean of the breaking elongation ET in the height direction of the packaging substrate 10, which is parallel to the axial direction of the sanitary paper roll 2 contained in the package 1 (direction A, indicated by arrow A in Figures 1 and 2), and the breaking elongation EH in the width direction of the packaging substrate 10, which is perpendicular to the axial direction of the sanitary paper roll 2 contained in the package 1 (direction B, indicated by arrow B in Figure 2), and can be calculated using the following formula (I):

[0128] GE = (ET × EH) 1 / 2 (I)

[0129] The breaking elongation ET in the height direction of the packaging substrate 10 and the breaking elongation EH in the width direction of the packaging substrate 10 are measured at the unsealed portion N12 of the package 1 (the joint portion of the packaging substrate 10).

[0130] The breaking elongation ET in the height direction (A direction) of the packaging substrate 10 and the breaking elongation EH in the width direction (B direction) of the packaging substrate 10 can be measured simultaneously when measuring the tensile strength in the height direction (A direction) of the packaging substrate 10 and the tensile strength in the width direction (B direction) of the packaging substrate 10 in accordance with JIS P8113:2006.

[0131] Here, in one aspect of the embodiment of the present invention, the packaging substrate 10 is used so that the MD direction (papermaking direction, longitudinal direction, T direction) of the paper substrate 100 included in the packaging substrate 10 coincides with the height direction (A direction) of the packaging substrate 10 in the package 1, and the CD direction (direction perpendicular to the papermaking direction, transverse direction, Y direction) of the paper substrate 10 included in the packaging substrate 10 coincides with the width direction (B direction) of the packaging substrate 10 in the package 1, but in the present invention, the orientation of the packaging substrate 10 in the package 1 is not limited to this. In another aspect of the embodiment of the present invention, the packaging substrate 10 is used so that the MD direction (papermaking direction, longitudinal direction, T direction) of the paper substrate 10 included in the packaging substrate 10 coincides with the width direction (B direction) of the packaging substrate 10 in the package 1, and the CD direction (direction perpendicular to the papermaking direction, transverse direction, Y direction) of the paper substrate 10 included in the packaging substrate 10 coincides with the height direction (A direction) of the packaging substrate 10 in the package 1.

[0132] The geometric mean breaking elongation of the packaging substrate 10 can be controlled by adjusting the breaking elongation in the height direction and the width direction of the packaging substrate 10, and as described above, the height direction of the packaging substrate 10 corresponds to the MD direction or CD direction of the packaging substrate 10, and the width direction of the packaging substrate 10 corresponds to the CD direction or MD direction of the packaging substrate 10. Therefore, the geometric mean breaking elongation of the packaging substrate 10 can be interpreted as the geometric mean breaking elongation of the breaking elongation in the MD direction (papermaking direction, longitudinal direction, T direction) of the packaging substrate 10 and the breaking elongation in the CD direction (direction perpendicular to the papermaking direction, transverse direction, Y direction) of the packaging substrate 10, and can be controlled by adjusting the breaking elongation in the MD direction of the packaging substrate 10 and the breaking elongation in the CD direction of the packaging substrate 10.

[0133] The breaking elongation in the MD direction of the packaging substrate 10 and the breaking elongation in the CD direction of the packaging substrate 10 can be adjusted by changing any one or a combination of two or more of the following conditions during the papermaking process of the paper substrate 100: (1) adjusting the ratio of softwood pulp to hardwood pulp; (2) adjusting the freeness; and during the production of the packaging substrate 10: (3) the type of sealing agent used in the sealing layer; and (4) the basis weight of the sealing layer.

[0134] [Effects of the first embodiment] A first embodiment of the present invention is a sanitary paper roll package in which multiple sanitary paper rolls are packaged in a packaging base material. The packaging base material has a layer structure including a paper base material and a seal layer for sealing the package. The thickness of the packaging base material is 35 μm to 80 μm, the burst strength of the packaging base material is 105 kPa to 190 kPa, and the geometric mean breaking elongation of the height direction of the packaging base material parallel to the axial direction of the sanitary paper rolls contained in the package and the width direction of the packaging base material perpendicular to the axial direction of the sanitary paper rolls contained in the package is 2.9% to 6.0%.

[0135] In the sanitary paper roll packaging 1 of the first embodiment, the thickness, burst strength, and geometric mean breaking elongation of the packaging base material 10 are within the specified ranges described above. This means that the packaging base material 10 is flexible and has excellent processability during manufacturing of the packaging 1; it is not easily torn by finger pressure when the packaging 1 is pinched, and the packaging 1 is easy to open. After opening, when some of the multiple sanitary paper rolls 2 contained in the packaging 1 are removed and the remaining sanitary paper rolls 2 are repackaged with the packaging base material 10, the packaging base material 10 is flexible and easy to repackage the packaged items 2; and the packaging 1 is not easily opened naturally over time after repackaging, providing excellent repackaging properties.

[0136] <Second embodiment> Next, a second embodiment of the present invention will be described. Unless otherwise specified, the configurations applicable to the first embodiment are also applicable to this aspect.

[0137] The second embodiment of the present invention is a preferred aspect of the first embodiment, and is characterized in that the air permeability of the packaging substrate 10 of the sanitary paper roll packaging 1 is 1,000 seconds or more. The air permeability of the packaging substrate 10 is preferably 10,000 seconds or more, and more preferably 20,000 seconds or more.

[0138] The air permeability of the packaging substrate 10 is measured at the unsealed portion N12 of the packaging body 1 (the joint portion of the packaging substrate 10).

[0139] The air permeability (Oken type) of the packaging substrate 10 can be calculated as the average of the air permeability (air permeability of the surface) measured using an Oken type air permeability tester in accordance with JIS P8117:2009, with the surface of the packaging substrate 10 (the surface that will become the outer surface of the packaging body 1) as the measurement surface and placed on the pressure measuring chamber side, and the air permeability (air permeability of the back surface) measured using the back surface of the packaging substrate 10 (the surface that will become the inner surface of the packaging body 1, i.e., the surface that comes into contact with the sanitary paper roll 2, which is the packaged item of the packaging body 1) as the measurement surface and placed on the pressure measuring chamber side.

[0140] [Action and effect] The higher the air permeability (the larger the number of seconds), the more difficult it is for air to pass through, indicating poor breathability. If the packaging substrate 10 has an air permeability of 1000 seconds or more, it is possible to prevent odor transfer, in which external odors are transferred to the packaged item (sanitary paper roll) 2 contained in the packaging 1 during storage periods such as when the packaging 1 is stored in a warehouse or when it is displayed in a store.

[0141] [Means of achievement] In order to achieve an air permeability of 1000 seconds or more for the packaging substrate 10, a paper substrate with high air permeability can be used as the paper substrate 100 included in the packaging substrate 10. An example of such a paper substrate is glassine paper. Another means for achieving an air permeability of 1000 seconds or more for the packaging substrate 10 is to completely cover one side of the paper substrate 100 with a sealing layer 110. The air permeability of the packaging substrate 10 can be further increased by using, as the sealing layer 110, a sealing layer formed by extruding a thermoplastic resin or a composition containing a thermoplastic resin, or a sealing layer formed by attaching a film made of a thermoplastic resin or a film containing a thermoplastic resin using a lamination processing device.

[0142] <Third embodiment> Next, a third embodiment of the present invention will be described. Unless otherwise specified, the configurations applicable to the above-described embodiments are also applicable to this aspect.

[0143] The third embodiment of the present invention is a preferred aspect of the above-described embodiments, and is characterized in that the bending stiffness of the packaging substrate 10 in the width direction is 8 μNm or more and 35 μNm or less. The bending stiffness of the packaging substrate 10 in the width direction is preferably 10 μNm or more and 30 μNm or less, and more preferably 15 μNm or more and 25 μNm or less.

[0144] The bending stiffness of the packaging substrate 10 is measured at the unsealed portion (joint portion of the packaging substrate 10) N12 of the package 1.

[0145] The bending stiffness of the packaging substrate 10 can be measured using a bending tester such as an L&W bending tester (manufactured by Lorentzen & Wettre) in accordance with the method described in JIS P8125-1:2017. Specifically, the bending stiffness (μN·m) is calculated by the following calculation formula (II) using the bending resistance (load) measured for a test piece of the packaging substrate 10 having a width of 38 mm and a length of 100 mm, at a bending angle of 15 degrees and a bending length (span of the sample stage) of 10 mm.

[0146] Bending stiffness (μN·m) = 60 × bending resistance (mN) × bending length 10 (mm) 2 ÷(π × bending angle 15 (°) × sample width 38 (mm)) (II)

[0147] The width direction of the packaging substrate 10 is a direction perpendicular to the axial direction of the sanitary paper roll 2 contained in the package 1 (direction A indicated by arrow A in Figures 1 to 3), and is direction B indicated by arrow B in the plan views of Figures 2 and 3. The bending stiffness when the width direction of the packaging substrate 10 (direction B indicated by arrow B in the figures) is the length direction of the test piece is the bending stiffness of the packaging substrate 10 in the width direction. If it is not possible to obtain a test piece with a length of 100 mm, the length of the test piece can be shortened.

[0148] [Action and effect] If the bending stiffness in the width direction of the packaging substrate 10 is too small, the rigidity is low and the substrate is prone to tearing, resulting in poor processability during manufacturing. If the bending stiffness in the width direction of the packaging substrate 10 is too large, the packaging substrate 10 becomes difficult to bend, resulting in poor repackaging properties. If the bending stiffness in the width direction of the packaging substrate 10 is 8 μNm or more and 35 μNm or less, a package 1 can be obtained that has good processability during manufacturing and good repackaging properties.

[0149] [Means of achievement] The bending stiffness of the packaging substrate 10 is greatly affected by its thickness (paper thickness). If the thickness is reduced, it becomes easier to bend, but also more prone to tearing. One method for reducing the thickness (paper thickness) is to adjust the basis weight when producing the paper substrate 100. Generally, the greater the basis weight of the paper substrate 100, the greater the thickness (paper thickness), and the smaller the basis weight of the paper substrate 100, the thinner it tends to be.

[0150] <Fourth embodiment> Next, a fourth embodiment of the present invention will be described. Unless otherwise specified, the configurations applicable to the above-described embodiments are also applicable to this aspect.

[0151] The fourth embodiment of the present invention is a preferred aspect of the above-described embodiments, and is characterized in that the smoothness of the surface of the packaging substrate 10 (the back surface of the packaging substrate 10) that comes into contact with the packaged object (sanitary paper roll) 2 contained in the package 1 is 100 seconds or more. The smoothness of the back surface of the packaging substrate 10 is more preferably 300 seconds or more, and even more preferably 500 seconds or more.

[0152] The smoothness of the back surface of the packaging substrate 10 is measured at the non-sealed portion (joint portion of the packaging substrate 10) N12 of the package 1.

[0153] The smoothness (Oken method) of the packaging substrate 10 can be measured in accordance with JIS P 8155:2010.

[0154] [Action and effect] If the smoothness of the surface of the packaging substrate 10 (the back surface of the packaging substrate 10) that comes into contact with the packaged item (sanitary paper roll) 2 contained in the package 1 is less than 100 seconds, the surface roughness will cause friction between the packaged item 2 and the packaging substrate 10 when vibrations or the like occur during the manufacture of the package 1 or in the manufactured package 1, and the surface properties of the packaged item will likely deteriorate. If the smoothness of the back surface of the packaging substrate 10 is 100 seconds or more, the phenomenon of deterioration in the surface properties of the packaged item will be less likely to occur.

[0155] [Means of achievement] As means for making the smoothness of the packaging substrate 10 100 seconds or more, there are a number of ways to use paper that is originally highly smooth as the paper substrate 100 of the packaging substrate 10, a way to strengthen the calendaring conditions of paper with low smoothness to adjust the smoothness and use it as the paper substrate 100 of the packaging substrate 10, and a way to use the side with higher smoothness (glossy side) as the back side of the packaging substrate 10 when using paper with a difference between the front and back, such as one-sided gloss paper, as the paper substrate 100.

[0156] <Other> (1) Packaging format of package 1 In the above-described embodiment, a caramel packaging format is given as an example of the packaging format of the packaging body 1, but the packaging format applicable to the present invention is not limited to this. Any known packaging format, such as a gusset packaging format, may be adopted as the packaging format of the packaging body 1 according to the embodiment of the present invention. In particular, as long as it is practicable and consistent, any combination of joining methods, such as overlapping joining, in which different surfaces of the packaging substrate 10 are joined together, and flaps joining, in which the same surfaces of the packaging substrate 10 are joined together, may be adopted to seal the packaging body 1, as long as it is practicable and consistent.

[0157] In the above-described embodiment, a caramel packaging format is used, and packaging is performed so that the seal layer 110 of the packaging base material 10 faces the outer surface of the package 1, but the embodiment of the present invention is not limited to this. For example, when a packaging format using a butt-seamed seam, such as a gusset packaging format, is used, packaging may be performed so that the seal layer 110 of the packaging base material 10 faces the inner surface of the package 1.

[0158] According to a packaging format in which the sealing layer 110 of the packaging base material 10 is on the outer surface side of the packaging body 1, if the sealing layer 110 is a heat-seal layer, the sealing layer 110 of the packaging base material 10 of the packaging body 1 can be used to join the handle to the packaging body itself, for example, when it is desired to attach a strip-shaped handle made of a paper base material to the packaging body 1.

[0159] (2) Layer structure of packaging substrate 10 In one embodiment of the present invention, the packaging substrate 10 may be provided with other layers in addition to the sealing layer 110. Examples of other layers include functional layers such as a water vapor barrier layer, an oxygen barrier layer, a printing layer, a printability improving layer, an overprint layer, and a light-blocking layer. These other layers may be provided, as necessary, on the surface (front surface) of the packaging substrate 10 that will be the outer surface of the packaging body 1, the surface (back surface) of the packaging substrate 10 that will be the inner surface of the packaging body 1, between the paper substrate 100 and the sealing layer 110, or on the top surface of the sealing layer 110 so as not to impair the adhesiveness or heat-sealability of the sealing layer. The other layer may be a single layer, or two or more layers.

[0160] Even when the packaging substrate 10 includes other layers, the physical properties of the packaging substrate 10 according to the embodiment of the present invention are measured at the non-sealed portion N12 of the packaging body 1 (the joint portion of the packaging substrate 10). Therefore, for example, if the non-sealed portion N12 of the packaging body 1 includes a layer having some functionality as described above (hereinafter also referred to as a functional layer), the thickness (paper thickness) of the packaging substrate 10 will be a thickness including the thickness of the paper substrate and the thickness of the functional layer. Furthermore, if the non-sealed portion N12 of the packaging body 1 does not include the seal layer 110 and the functional layer as described above, the thickness (paper thickness) of the packaging substrate 10 will essentially be the thickness of the paper substrate.

[0161] (3) Proportion (mass ratio) of paper substrate in packaging substrate 10 In one embodiment of the present invention, the proportion (mass ratio) of the paper substrate 100 in the packaging substrate 10 is preferably 51 mass % or more.

[0162] The proportion of the paper substrate can be calculated as the percentage of the basis weight of the paper substrate in the basis weight of the packaging substrate using the formula "(basis weight of paper substrate) ÷ (basis weight of packaging substrate) × 100" (unit: %).

[0163] The basis weight of the packaging substrate used when calculating the proportion of the paper substrate is the basis weight including the non-jointed portion N12 and the jointed portions (12S, 12T, 12B) of the packaging substrate 10. Components other than the paper substrate 100 that make up the packaging substrate 10 include the sealant contained in the seal layer 110 and the functional materials contained in the functional layer described above, such as resin components. These components other than the paper substrate 100 are preferably biodegradable.

[0164] In Japan, the Resources Effective Utilization Promotion Act requires that composite materials made of plastic and paper have an identification mark for the predominant material by mass. That is, if the plastic content of the packaging substrate 10 exceeds 50% by mass, a plastic mark must be displayed, and if the paper content exceeds 50% by mass, a paper mark must be displayed.

[0165] When the proportion (mass ratio) of the paper base material 100 in the packaging base material 10 is 51 mass % or more, a paper mark can be displayed on the packaging base material 10. By displaying the paper mark, the packaging base material 10 of the package 1 can be disposed of in the same way as paper.

[0166] Furthermore, when the proportion (mass ratio) of paper base material 100 in packaging base material 10 is 51 mass % or more, the amount of resin used is significantly reduced compared to packaging films that are made of 100% general resin film (excluding biodegradable polyethylene film, polypropylene film, etc.), which are commonly used in packaging sanitary paper rolls, making it possible to eliminate or reduce the use of plastic.

[0167] (3) Handle of the package The packaging body 1 according to the embodiment of the present invention may further include a handle (not shown) for carrying the packaging body 1. Note that the handle is not an essential component of the present invention. The handle may be, for example, a strip-shaped handle with both ends joined to the outer surface of the packaging body. The material of the handle may be a film or a base material mainly made of paper (paper base material).

[0168] When the sealing agent contained in the sealing layer 110 of the packaging base material 10 of the packaging body 1 is a heat sealing agent, it is preferable to use a paper base material for the handle, as this makes it possible to use the sealing layer 110 of the packaging base material 10 of the packaging body 1 to join the handle to the packaging body itself. [Example]

[0169] The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to the examples shown below.

[0170] Example 1 Glassine paper was used as the paper substrate, and a 15 μm thick polyethylene layer was formed on one entire surface of the paper substrate by extrusion to form a sealing layer, thereby obtaining a packaging substrate.

[0171] Two kitchen paper rolls (roll width 230 mm, roll diameter 115 mm, roll length 22.7 m) were arranged in two horizontal rows and one vertical row using the obtained packaging base material, and were packaged in a caramel packaging format with the seal layer of the packaging base material facing the outer surface of the package, to obtain the package of Example 1 shown in Figure 1. At this time, the packaged item was wrapped using the packaging base material so that the axial direction of the kitchen paper roll (direction A indicated by arrow A in Figure 1) was parallel to the MD direction of the paper base material.

[0172] (Examples 2 to 4, Comparative Examples 1 and 2) Using a paper substrate (glassine paper) with a different basis weight from that of Example 1 (glassine paper), packages of Examples 2 to 4 and Comparative Examples 1 and 2 were obtained in the same manner as Example 1. The examples with the lowest basis weight of the paper substrate are Comparative Example 1, Example 3, Example 2, Example 1, Example 4, and Comparative Example 2.

[0173] (Examples 5 and 6, Comparative Examples 3 and 4) Packages of Examples 5 and 6 and Comparative Examples 3 and 4 were obtained in the same manner as in Example 1, using paper substrates (glassine paper) with different amounts of strength agent added than the paper substrate (glassine paper) of Example 1. The paper substrates of Example 5 and Comparative Example 3 had a smaller amount of strength agent added than the paper substrate of Example 1. The paper substrates of Example 6 and Comparative Example 4 had a larger amount of strength agent added than the paper substrate of Example 1.

[0174] (Examples 7 and 8) Packages of Examples 7 and 8 were obtained in the same manner as in Example 1, except that a paper base material (glassine paper) with a different T / Y ratio from that of Example 1 (glassine paper) was used.

[0175] Here, the "T / Y ratio" is an index of the directionality of tensile strength based on the orientation of the pulp fibers that make up the paper base material. It is the strength ratio between the machine direction (MD) of the paper flow in the papermaking machine and the cross direction (Y) of the direction perpendicular to it (CD), and is also called the "aspect ratio."

[0176] The paper base material of Example 7 has a smaller T / Y ratio than the paper base material of Example 1. The paper base material of Example 8 has a larger T / Y ratio than the paper base material of Example 1. The T / Y ratio can be controlled, for example, by adjusting the jet-to-wire ratio (J / W), which is the ratio between the jet speed (J), which is the ejection speed of the pulp dispersion, and the wire speed (W) in the paper machine when producing the paper base material.

[0177] Example 9 A package of Example 9 was obtained in the same manner as in Example 1, using one-sided glossy paper instead of glassine paper as the paper substrate. In this case, the sealing layer was applied to the entire non-glossy side of the one-sided glossy paper, which is the side with relatively low smoothness. Furthermore, the glossy side of the one-sided glossy paper, which is the side with relatively high smoothness, was used as the side that would come into contact with the kitchen paper roll contained in the package. The basis weight (30.0 g / m) of the paper substrate (one-sided glossy paper) of Example 9 was 100%. 2 ) is the basis weight (40.0 / m ) of the paper base material (glassine paper) in Example 1 2 ), and the basis weight of the paper base material (glassine paper) in Example 2 (basis weight 30.5 g / m 2 ) was comparable to that of

[0178] Example 10 Instead of forming a polyethylene layer by extrusion onto the entire surface of one side of the paper substrate to form a seal layer, a heat seal agent was applied to a portion of one side of the paper substrate (a predetermined area that will become the joint of the packaging substrate, shown by hatching in (a) of Figure 3) to form a heat seal layer, and the package of Example 10 was obtained in the same manner as in Example 1. A polyolefin-based aqueous heat seal agent was used as the heat seal agent, and a roll coater was used for coating.

[0179] (Comparative Examples 5 and 6) Using a paper substrate (glassine paper) with a different basis weight from that of Example 10, packages of Comparative Examples 5 and 6 were obtained in the same manner as Example 10. The examples with the lowest basis weight of the paper substrate are Comparative Example 6, Comparative Example 5, and Example 10.

[0180] (Comparative Example 7) Instead of glassine paper, one-sided glossy paper was used as the paper substrate, and instead of forming a polyethylene layer by extrusion on the entire one side of the paper substrate to form a seal layer, a heat-sealing agent was applied to a portion of one side of the paper substrate (a predetermined area that will become the joint of the packaging substrate, shown by hatching in (a) of Figure 3) to form a heat-sealing layer, and a package of Comparative Example 7 was obtained in the same manner as in Example 1. In this case, the heat-sealing layer was applied to the entire non-glossy side, which is the side with relatively low smoothness, of both sides of the one-sided glossy paper. In addition, the glossy side, which is the side with relatively high smoothness, of both sides of the one-sided glossy paper was used as the side that would come into contact with the kitchen paper roll contained in the package. As in Example 10, a polyolefin-based aqueous heat-sealing agent was used as the heat-sealing agent, and a roll coater was used for coating.

[0181] The basis weight of the paper base material (one-sided glossy paper) in Comparative Example 7 (50.5 g / m 2 ) is the basis weight (40.0 / m ) of the paper base material (glassine paper) in Example 1 2 ) was higher than

[0182] [Physical properties of packaging substrate] The physical properties of the paper substrate and packaging substrate used in each example are shown in Tables 1 to 4. The physical properties were measured in an environment conforming to Japanese Industrial Standard JIS P8111 (temperature 23±1°C, humidity 50±2% RH) after the samples were conditioned for 48 hours.

[0183] (basis weight of paper base material) Based on JIS P8124, the basis weight per sheet of paper (unit: g / m 2 ) was measured.

[0184] (Basis weight of packaging substrate) In accordance with JIS P8124, the basis weight per sheet of packaging substrate (unit: g / m 2 The measurement was carried out on the region of the non-sealed portion of the package (non-jointed portion of the packaging substrate), avoiding the sealed portion of the package (jointed portion of the packaging substrate).

[0185] (Seal layer basis weight) In each example (Examples 1 to 9 and Comparative Examples 1 to 4) in which the sealing layer was formed by extrusion, the basis weight of the sealing layer was calculated by subtracting the basis weight of the paper substrate from the basis weight of the packaging substrate obtained by the above measurement method, and was determined by the formula "(basis weight of packaging substrate) - (basis weight of paper substrate)" (unit: g / m 2 ).

[0186] (Sealing layer coating amount) For each example (Example 10 and Comparative Examples 5 to 7) in which the sealing layer was formed by coating with a roll coater, the basis weight of the sealing layer was determined as the amount of sealing agent applied per unit area in the sealing agent-coated portion of the packaging substrate.

[0187] (Thickness of packaging substrate (paper thickness)) The thickness of the packaging substrate (paper thickness) was measured (unit: μm) in accordance with ISO534:2011. The pressure on the pressure surface during measurement was 100 kPa ± 10 kPa. Measurements were taken on the unsealed area of ​​the package, avoiding the sealed area.

[0188] (Density of packaging substrate) The density of the packaging substrate is a calculated value obtained from the basis weight of the packaging substrate obtained by the above measurement method and the thickness (paper thickness) of the packaging substrate, and was calculated using the formula "(basis weight of packaging substrate) ÷ (thickness of packaging substrate (paper thickness))" (unit: g / cm 3 ).

[0189] (Smoothness of packaging substrate) The smoothness (Oken method) of the backside of the packaging substrate was measured (unit: seconds) in accordance with JIS P8155:2011. The measurement was carried out on the unsealed area of ​​the package, avoiding the sealed area. The surface of the packaging substrate that comes into contact with the kitchen paper roll contained in the package was defined as the "backside of the packaging substrate."

[0190] (Air permeability of packaging substrate) In accordance with JIS P8117:2009, the air permeability (Oken method) of both the front and back surfaces of the packaging substrate was measured, and the average air permeability of both surfaces was calculated and used as the air permeability of the packaging substrate (unit: seconds). Measurements were taken on the unsealed area of ​​the package, avoiding the sealed area. The surface of the packaging substrate that comes into contact with the kitchen paper roll contained in the package was designated the "back surface of the packaging substrate," and the surface of the packaging substrate that faces the outside of the package was designated the "front surface of the packaging substrate."

[0191] (Transparency of packaging substrate) The transparency of the packaging substrate was measured (unit: %) using a diffuse light transmittance meter DOT-5 (manufactured by Murakami Color Research Laboratory Co., Ltd.) in accordance with ISO 5-2. The measurement was performed on the unsealed area of ​​the package (the unjoined area of ​​the packaging substrate), avoiding the sealed area of ​​the package (the joined area of ​​the packaging substrate).

[0192] (Burst strength of packaging substrate) The burst strength of the packaging substrate was measured (unit: kPa) in accordance with JIS P8112:2008. The measurement was carried out on the unsealed area of ​​the package (unjoined area of ​​the packaging substrate), avoiding the sealed area of ​​the package (joined area of ​​the packaging substrate).

[0193] (Tensile strength of packaging substrate) The tensile strength of the packaging substrate in the longitudinal and transverse directions was measured (unit: kN / m) in accordance with JIS P8113:2006. The measurements were carried out on the unsealed area of ​​the package (the unjoined area of ​​the packaging substrate), avoiding the sealed area of ​​the package (the joined area of ​​the packaging substrate).

[0194] (Breaking elongation of packaging substrate) The breaking elongation of the packaging substrate can be measured simultaneously with the measurement of the tensile strength of the packaging substrate. When measuring the tensile strength in the longitudinal and transverse directions of the packaging substrate, the breaking elongation in the longitudinal and transverse directions of the packaging substrate was also measured, and this was interpreted as the breaking elongation in the height direction and transverse direction of the packaging substrate (unit: %).

[0195] (Geometric mean breaking elongation of packaging substrate) The geometric mean breaking elongation (GE) of the packaging substrate is the geometric mean of the breaking elongation (ET) in the height direction of the packaging substrate and the breaking elongation (EH) in the width direction of the packaging substrate obtained by the above measurement method, and is calculated by the formula "{breaking elongation (ET) in the height direction of the packaging substrate × breaking elongation (EH) in the width direction of the packaging substrate}" 1 / 2 " (unit: %).

[0196] (Bending stiffness of packaging substrate) In accordance with JIS P8125-1:2017, the bending stiffness of the packaging substrate in the height and width directions was measured using an L&W bending tester (manufactured by Lorentzen & Wettre) (unit: μN·m). Specifically, the bending stiffness was calculated using the following formula, using the bending resistance (load) measured for a test piece of packaging substrate 10 measuring 38 mm wide and 100 mm long, with a bending angle of 15 degrees and a bending length (span of the sample stage) of 10 mm.

[0197] Bending stiffness (μN·m) = 60 × bending resistance (mN) × bending length 10 (mm) 2 ÷(π × bending angle 15 (°) × sample width 38 (mm))

[0198] Measurements were performed on the unsealed portion of the packaging body (unjoined portion of the packaging substrate), avoiding the sealed portion of the packaging body (joined portion of the packaging substrate). The direction of the packaging substrate parallel to the axial direction of the sanitary roll contained in the packaging body was defined as the "height direction of the packaging substrate," and the direction of the packaging substrate perpendicular to the axial direction of the sanitary roll contained in the packaging body was defined as the "width direction of the packaging substrate." The bending stiffness when the vertical direction of the packaging substrate was taken as the length direction of the test piece was defined as the "vertical bending stiffness of the packaging substrate," and the bending stiffness when the width direction of the packaging substrate was taken as the length direction of the test piece was defined as the "width direction bending stiffness of the packaging substrate."

[0199] [Sensory test] The following sensory tests were carried out on the packages obtained in each example.

[0200] (Resistant to tearing of packaging substrate) When the package was held in one hand and carried, the presence or absence of tears in the packaging base material was observed from areas where finger pressure was applied. One tester tested 20 packages for each example, and the percentage of packages that were not torn was evaluated on a four-point scale. The higher the evaluation number, the better (4 (excellent) → 1 (poor)).

[0201] (Ease of repackaging the packaged item) The packages obtained in each example were manually opened, one of the two kitchen paper rolls contained inside was removed, and the remaining packaging base material was used to repackage the remaining kitchen paper roll inside the package, preventing the outer surface of the kitchen paper roll from being exposed. Thirty testers evaluated the ease of repackaging and whether the package remained unopened over time after repackaging. The opening and repackaging methods used in the test are shown in Figures 4 and 5, but are not limited to these and were left to the discretion of each tester. A higher evaluation value indicates better performance (4 (excellent) → 1 (poor)).

[0202] (Odor transfer to packaged items) The package obtained in each example and a nonwoven fabric dashi bag containing 30 g of coffee powder were placed into a zippered plastic bag (Unipack (registered trademark) thick L-8 (dimensions 340 mm x 480 mm, thickness 0.08 mm) and then sealed. The bag was then stored for one week in an environment with a temperature of 23°C and a humidity of 50% RH. After storage, the package was removed from the plastic bag and opened, and five testers rated the coffee odor perceived from the kitchen paper roll according to the following criteria. The evaluation values ​​shown in the table are the average scores of the five testers rounded up or down. A higher evaluation value indicates that the odor is less noticeable and is therefore better (3 (excellent) → 1 (poor)).

[0203] 3: You can barely smell the coffee 2: A slight smell of coffee 1: I can smell the strong smell of coffee

[0204] (Visibility of packaged items) The packaging obtained in each example was evaluated by 30 testers regarding the ease of checking the condition (embossing, perforations, color) of the packaged item (kitchen paper roll) from the outside of the packaging. The higher the evaluation number, the better the visibility (4 (excellent) → 1 (poor)).

[0205] [Test Results] The test results are shown in Tables 1 to 4. Note that Example 10 and Comparative Examples 5 to 7 do not have a seal layer in the non-jointed portion of the packaging substrate, which corresponds to the non-sealed portion of the package, and therefore the physical properties of the packaging substrate in Example 10 and Comparative Examples 5 to 7 are essentially the physical properties of the paper substrate.

[0206] [Table 1]

[0207] [Table 2]

[0208] [Table 3]

[0209] [Table 4]

[0210] All of the samples from Example 1 to Comparative Example 7 (all samples) were kitchen paper roll packages in which two sanitary paper rolls were wrapped in a packaging base material, and the packaging base material had a layer structure including a paper base material and a sealing layer for sealing the package.

[0211] As shown in Tables 1 and 2, the kitchen paper roll packages of Examples 1 to 10 all had a packaging substrate thickness of 35 μm or more and 80 μm or less, a packaging substrate burst strength of 105 kPa or more and 190 kPa or less, and the geometric mean breaking elongation of the height direction of the packaging substrate parallel to the axial direction of the kitchen paper roll contained in the package and the width direction of the packaging substrate perpendicular to the axial direction of the kitchen paper roll contained in the package was 2.9% or more and 6.0% or less.

[0212] The kitchen paper roll packages of Examples 1 to 10 were all rated 3 (good) or 4 (excellent) for "resistance to tearing of packaging base material" (4-point scale), and were not easily torn when held between fingers and carried.

[0213] Furthermore, the "ease of repackaging the packaged item" (4-point scale) was rated 2 (fair) for Example 4, in which the paper base material and therefore the packaging base material had a relatively high basis weight and a relatively high thickness (paper thickness), Example 6, in which a relatively large amount of paper strength agent was added during papermaking of the paper base material, and Example 7, in which the T / Y ratio of the paper base material was relatively low and anisotropy was small, while the other Examples were rated 3 (good) or 4 (excellent), indicating ease of repackaging.

[0214] In addition, in terms of "odor transfer to the packaged item" (3-point scale), Example 10, in which the sealing layer was formed by coating with an aqueous sealing agent, was rated 2, indicating slight odor transfer, while Examples 1 to 9, in which the sealing layer was formed by film formation using an extrusion method, were rated 3, indicating almost no odor transfer and were good.

[0215] In addition, the "visibility of the packaged item" (rated on a four-point scale) was rated 2 for Example 9, which had a paper base material made of glossy paper on one side, indicating slightly low visibility, while Examples 1 to 3, 5 to 8, and 10, which had a paper base material made of glassine paper, were rated 4, indicating excellent visibility.

[0216] In Comparative Example 1, the paper substrate and therefore the packaging substrate had a lower basis weight compared to Examples 1 to 3. The thickness of the packaging substrate in Comparative Example 1 was 37 μm, which was within the range specified in the present invention, but the burst strength (90 kPa) and geometric mean elongation at break (2.40%) were outside the range specified in the present invention and were low, and the "resistance to tearing of the packaging substrate" was rated 1 (poor), meaning it was easily torn. Furthermore, the bending stiffness (width direction) of Comparative Example 1 was 6.5 μNm, which was lower than that of the Examples and made it easy to bend, and the "ease of repackaging the packaged item" was rated 4, meaning it was excellent.

[0217] In Comparative Example 2, the paper substrate, and therefore the packaging substrate, had a higher basis weight than in Examples 1 and 4. The thickness of the packaging substrate in Comparative Example 2 was 78 μm, which was within the range specified in the present invention, but the burst strength (233 kPa) and geometric mean breaking elongation (6.13%) were both high and outside the range specified in the present invention. Furthermore, the bending stiffness (width direction) of Comparative Example 2 was 49.8 μNm, which was higher than that of the Examples. The "ease of repackaging the packaged item" of Comparative Example 2 was rated 1, which was poor. Furthermore, the transparency of Comparative Example 2 was 57.0%, which was lower than that of the Examples, and the "visibility of the packaged item" (rated on a four-point scale) was rated 1, which was poor.

[0218] In Comparative Example 3, the amount of paper strength agent added during papermaking of the paper base material was smaller than in Example 1. The thickness of the packaging base material in Comparative Example 3 was 52 μm, which was within the range specified in the present invention, but the burst strength (99 kPa) and geometric mean breaking elongation (2.33%) of Comparative Example 3 were low and outside the range specified in the present invention, and the "resistance to tearing of the packaging base material" was rated 1, which was poor. Furthermore, the bending stiffness (width direction) of Comparative Example 3 was 4.1 μNm, which was lower than that of Example 1 (20.1 μNm), and the "ease of repackaging the packaged item" was rated 4, which was excellent.

[0219] In Comparative Example 4, a larger amount of paper strength agent was added during papermaking of the paper base material than in Example 1. The thickness of the packaging base material in Comparative Example 4 was 52 μm, which was within the range specified in the present invention, but the burst strength (202 kPa) of Comparative Example 4 was outside the range specified in the present invention and was a high value. In addition, the geometric mean breaking elongation (5.59%) was within the range specified in the present invention but was a little high. In addition, the bending stiffness (width direction) of Comparative Example 4 was 33.5 μNm, which was higher than that of Example 1 (20.1 μNm). The "ease of repackaging of packaged items" of Comparative Example 4 was rated 1, which was poor.

[0220] In Comparative Example 5, the paper substrate had the same basis weight as in Example 2, but the sealing agent coating method was different from that in Example 2, and the coating amount (basis weight) of the sealing layer was lower. The thickness of the packaging substrate in Comparative Example 5 was 29 μm, which was outside the range specified in the present invention and thin, and the "odor transfer to the packaged item" was rated 2, which was inferior to Example 2. The burst strength (96 kPa) and geometric mean breaking elongation (2.63%) of Comparative Example 5 were low, outside the range specified in the present invention, and the "resistance to tearing of the packaging substrate" was rated 1, which was inferior. Furthermore, the bending stiffness (width direction) of Comparative Example 5 was 8.7 μNm, which was lower than that of Example 2 (12.1 μNm), and the "ease of repackaging the packaged item" was rated 4, which was excellent.

[0221] In Comparative Example 6, the paper substrate had the same basis weight as in Example 3, but the sealing agent coating method was different from that in Example 3, and the coating amount (basis weight) of the sealing layer was lower. The thickness of the packaging substrate in Comparative Example 6 was 25 μm, which was outside the range specified in the present invention and thin, and the "odor transfer to the packaged item" was rated 2, which was inferior to Example 3. The burst strength (91 kPa) and geometric mean breaking elongation (2.46%) of Comparative Example 6 were low, outside the range specified in the present invention, and the "resistance to tearing of the packaging substrate" was rated 1, which was inferior. Furthermore, the bending stiffness (width direction) of Comparative Example 6 was 4.8 μNm, which was lower than that of Example 3 (8.1 μNm), and the "ease of repackaging the packaged item" was rated 4, which was excellent.

[0222] In Comparative Example 7, the type of packaging substrate was the same as in Example 9 (single-sided glossy paper), but the sealing agent coating method was different from that in Example 9, and the coating weight (basis weight) of the sealing layer was lower. The thickness of the packaging substrate in Comparative Example 7 was 50 μm, which was within the range specified in the present invention but was thicker than that of Example 9 (45 μm). The transparency of the packaging substrate in Comparative Example 7 was 57.3%, which was lower than that of Example 9 (62.0%). In Comparative Example 7, the "odor transfer to packaged item" and "visibility of packaged item" were both rated 1, which was inferior to that of Example 9. The burst strength (102 kPa) and geometric mean breaking elongation (2.73%) of Comparative Example 7 were low and outside the range specified in the present invention, and the "tear resistance of the packaging substrate" was rated 1, which was inferior. [Explanation of symbols]

[0223] 1. Sanitary paper roll packaging (packaging) 2. Sanitary paper roll (kitchen paper roll) (packaged item) 10 Packaging base material 100 Paper base material 110 Sealing layer (heat sealing layer, adhesive layer)

Claims

1. A sanitary paper roll package in which a plurality of sanitary paper rolls are packaged in a packaging base material, The packaging substrate has a layer configuration including a paper substrate and a seal layer for sealing the package, The thickness of the packaging substrate is 35 μm or more and 80 μm or less, The packaging substrate has a burst strength of 105 kPa or more and 190 kPa or less, A sanitary paper roll package characterized in that the geometric mean breaking elongation of the packaging substrate in the height direction parallel to the axial direction of the sanitary paper roll contained in the package and the geometric mean breaking elongation of the packaging substrate in the width direction perpendicular to the axial direction of the sanitary paper roll contained in the package is 4.11% or more and 6.0% or less.

2. 2. The sanitary paper roll package according to claim 1, wherein the packaging substrate has an air permeability of 1000 seconds or more.

3. The sanitary paper roll packaging according to claim 1 or 2, wherein the bending stiffness of the packaging base material in the width direction is 8 μNm or more and 35 μNm or less.

4. The sanitary paper roll packaging according to any one of claims 1 to 3, wherein the surface of the packaging base material that comes into contact with the sanitary paper roll contained in the packaging has a smoothness of 100 seconds or more.

5. The sanitary paper roll package according to any one of claims 1 to 4, wherein the transparency of the packaging base material is 60% or more.

6. The sanitary paper roll packaging according to any one of claims 1 to 5, wherein the paper base material is glassine paper.

7. The sanitary paper roll packaging body according to any one of claims 1 to 6, characterized in that the packaging body is packaged in a caramel packaging format.

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