Packaging bags and sheet packaging

Abstract

To provide a paper packaging bag easy to be opened.SOLUTION: A packaging bag accommodates a sheet, and is constituted by a substrate containing a paper component. The substrate includes a base layer containing the paper component, and an inner layer laminated on a surface of either side of the base layer and disposed inside the packaging bag. The inner layer includes thermoplastic resin, and the thermoplastic resin includes a slip agent.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to packaging bags and sheet packaging. [Background technology]

[0002] Sheet packaging, which contains sheets such as paper towels and tissue paper, is distributed and used in a state where multiple sheets are contained in a resin film packaging bag (for example, Patent Documents 1 and 2). In recent years, from the perspective of reducing environmental burdens such as global warming caused by CO2 emissions and marine pollution such as microplastics, the paperization of packaging bags in sheet packaging from resin to paper has attracted attention. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2008-183034 [Patent Document 2] Japanese Patent Publication No. 2018-177364 [Overview of the initiative] [Problems that the invention aims to solve]

[0004] However, paper packaging bags are less flexible than plastic packaging bags, so if perforations are provided for opening, the perforations are less likely to tear, making them difficult to open.

[0005] The object of this invention is to provide a paper packaging bag that is easy to open. [Means for solving the problem]

[0006] A first aspect of the present invention provides a packaging bag for containing a sheet, comprising a base material containing a paper component, wherein the base material includes a base layer containing the paper component and an inner layer laminated on either one surface of the base layer and disposed on the inside of the packaging bag, the inner layer containing a thermoplastic resin, and the thermoplastic resin containing a slip agent.

[0007] In this specification, the paper component is made of plant fibers bonded together. The inside of the packaging bag indicates the side where the base material comes into contact with the sheet contained in the packaging bag. The slip agent is an agent that reduces the coefficient of friction.

[0008] In the first embodiment, the base material of the packaging bag includes a base layer containing paper components and an inner layer laminated on either side of the base layer and placed on the inside of the packaging bag, wherein the inner layer contains a thermoplastic resin containing a slip agent, thereby reducing the static friction coefficient between the base material and the sheet. As a result, the base material becomes more slippery against the sheet, and if perforations are provided on a paper packaging bag, the perforations become easier to tear, making it easier to open even a paper packaging bag.

[0009] A second aspect of the present invention provides a packaging bag having a first static friction coefficient between the inner surface of the substrate on the side where the inner layer is formed and the sheet, wherein the first static friction coefficient is 0.55 or less.

[0010] In this specification, the coefficient of static friction is the ratio of the frictional force generated at the contact surface of two objects when they are not in relative motion to the force acting perpendicular to the contact surface. The inner surface on the side where the inner layer of the substrate is formed is the surface on which the substrate comes into contact with the sheet contained in the packaging bag.

[0011] In the second embodiment, the first static friction coefficient between the inner surface of the substrate containing paper components and the sheet is 0.55 or less, so that the inner surface of the substrate containing paper components is slippery against the sheet. As a result, the perforations on the paper packaging bag become easier to tear, making it easier to open the packaging bag.

[0012] A third aspect according to the present invention provides a packaging bag having a second coefficient of static friction between an outer surface of the base material disposed on an outer side of the packaging bag and artificial skin, wherein the second coefficient of static friction is larger than a first coefficient of static friction.

[0013] In the present specification, the outer surface of the base material disposed on the outer side of the packaging bag refers to a surface on the side that does not contact a sheet accommodated in the packaging bag. Artificial skin refers to a urethane molded product that imitates human skin.

[0014] In the third aspect, the second coefficient of static friction between the outer surface of the base material disposed on the outer side of the packaging bag and artificial skin is larger than the first coefficient of static friction on the inner surface side of the base material stomach As a result, the inner surface of the base material becomes slippery with respect to the sheet, and the outer surface of the base material becomes less slippery with respect to artificial skin. Therefore, perforations provided in a paper packaging bag are further easily cleaved, and opening of the packaging bag is further facilitated.

[0015] A fourth aspect according to the present invention provides a packaging bag wherein a ratio of the first coefficient of static friction to the second coefficient of static friction is 0.65 or less. In the present specification, the ratio of the first coefficient of static friction to the second coefficient of static friction indicates a ratio of the first coefficient of static friction relative to the second coefficient of static friction.

[0016] In the fourth aspect, by setting the ratio of the first coefficient of static friction to the second coefficient of static friction to 0.65 or less, the difference between the coefficient of friction on the inner surface side of the base material with respect to the sheet and the coefficient of friction on the outer surface side of the base material with respect to artificial skin is increased. Therefore, perforations provided in a paper packaging bag are further easily cleaved, and opening of the packaging bag is further facilitated.

[0017] A fifth aspect according to the present invention provides a packaging bag wherein the second coefficient of static friction is 1.1 or less. In a paper packaging bag, from the viewpoint of improving openability, the difference between the first coefficient of static friction and the second Silence coefficient of friction is preferably as large as possible. On the other hand, with respect to the first coefficient of static friction, the second SilenceIf the coefficient of friction becomes excessively large, the perforations provided on the packaging bag may tear before the packaging bag is opened (for example, during distribution of a sheet package using the packaging bag) due to frictional force from the outside of the packaging bag.

[0018] Accordingly, in the fifth aspect, by setting the second static friction coefficient to 1.1 or less, the second static friction coefficient is adjusted such that the outer surface of the base material does not become excessively non-slip, and unexpected tearing of the packaging bag can be prevented without degrading the openability of the packaging bag.

[0019] A sixth aspect according to the present invention provides a packaging bag, wherein the first static friction coefficient is a static friction coefficient between the CD direction of the base material and the MD direction of the sheet, and the second static friction coefficient is a static friction coefficient between the CD direction of the base material and artificial skin. In the present specification, the MD direction is a direction corresponding to the traveling direction of the base material relative to a paper machine for producing the base material constituting the paper packaging bag, and the CD direction is a direction corresponding to the direction perpendicular to the traveling direction.

[0020] In the sixth aspect, by setting the static friction coefficient between the CD direction of the base material and the MD direction of the sheet as the first static friction coefficient, the CD direction of the base material becomes slippery relative to the MD direction of the sheet. Furthermore, by setting the static friction coefficient between the CD direction of the base material and artificial skin as the second static friction coefficient, the artificial skin becomes less slippery relative to the CD direction of the base material.

[0021] Accordingly, when sheets are stored in the packaging bag such that the MD direction of the sheets is aligned along the CD direction of the base material, and perforations are formed in the MD direction of the base material, if a user presses the surface of the packaging bag where the perforations are formed with the thumbs of both hands and moves the thumbs apart from each other in the CD direction of the base material, the perforations will tear. At this time, the perforations tear easily with a small force, which further facilitates opening of the packaging bag.

[0022] A seventh aspect of the present invention provides a packaging bag in which a tear-off line is formed on the top surface of the packaging bag along the MD direction of the base material. In this specification, the tear-off line indicates a tear-off line (e.g., a perforation line) in which cuts and ties (uncut portions between two cuts) are arranged alternately, and when a tie is broken, the adjacent cuts become a continuous cut.

[0023] In the seventh embodiment, by forming a tear-off line along the MD direction of the base material on the top surface of the packaging bag, the packaging bag can be easily opened by simply pressing the top surface of the packaging bag with both thumbs and moving the thumbs away from each other in the CD direction of the base material, causing the tear-off line to tear. Furthermore, the torn tear-off line can form an opening for dispensing the sheet, which is formed on the top surface of the packaging bag.

[0024] An eighth aspect of the present invention provides a sheet packaging body comprising a packaging bag according to the first to seventh aspects and a sheet contained in the packaging bag. In the eighth aspect, the same effects as the packaging bag described above can be obtained by constructing a sheet packaging body in which a sheet is contained in the packaging bag described above. That is, according to the eighth aspect, even when the packaging bag constituting the sheet packaging body is made of paper, a sheet packaging body can be provided in which the paper packaging bag is easy to open. [Effects of the Invention]

[0025] According to one aspect of the present invention, it is possible to provide a paper packaging bag that is easy to open. [Brief explanation of the drawing]

[0026] [Figure 1] This figure shows a sheet package containing sheets in a packaging bag. [Figure 2] This diagram shows a sheet being placed inside a packaging bag. [Figure 3] This is a view of the sheet packaging shown in Figure 1, seen from the top. [Figure 4] This is a view of the sheet packaging shown in Figure 1, seen from the bottom. [Figure 5] Figure 1 is a view of the sheet packaging from the front. [Figure 6] This is a view of the sheet packaging shown in Figure 1, seen from the back. [Figure 7] This is a view of the sheet packaging shown in Figure 1, seen from the left side. [Figure 8] This is a view of the sheet packaging shown in Figure 1, seen from the right side. [Figure 9] This figure shows an example of a cross-section of the base material of a packaging bag (first embodiment). [Figure 10] This figure shows the sheet packaging with the packaging bag opened. [Figure 11] This diagram shows the usage status of the sheet packaging. [Figure 12] This figure shows an example of a cross-section of the base material of a packaging bag (second embodiment). [Modes for carrying out the invention]

[0027] <Package> Embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, common parts are denoted by the same reference numerals and their description may be omitted. Also, the scale of each part in each drawing may differ from the actual scale. In each drawing, a three-dimensional Cartesian coordinate system with three axes (X, Y, and Z directions) is used, with the longitudinal direction of the packaging bag being the X direction, the width direction being the Y direction, and the height direction (vertical or thickness direction) being the Z direction.

[0028] Figure 1 shows a sheet package containing a sheet in a packaging bag according to the embodiment. Figure 2 shows a sheet contained in the packaging bag according to the embodiment. Figures 3, 4, 5, 6, 7, and 8 are views of the sheet package of Figure 1 from the top, bottom, front, back, left, and right sides, respectively.

[0029] As shown in Figure 1, the sheet packaging 100 includes a packaging bag 10 and a sheet laminate 20 (multiple sheets S). The sheet packaging 100 is an example of a sheet packaging according to this embodiment. The packaging bag 10 is an example of a packaging bag that constitutes the sheet packaging according to this embodiment. The sheet laminate 20 is an example of a sheet contained in the packaging bag according to this embodiment.

[0030] As shown in Figure 2, the packaging bag 10 contains multiple stacked sheets S (sheet stack 20). The sheet stack 20 is housed in the packaging bag 10 such that the stacking direction (SD direction) of the sheets S is the height direction (Z direction). The sheet stack 20 is designed so that the sheets S can be pulled out one set at a time through an opening (opening OP) formed in the packaging bag 10, which will be described later (see Figure 11).

[0031] The form of the sheet laminate 20 is not particularly limited, and for example, sheets S can be laminated in a folded state, sheets S can be laminated alternately in a folded state (a so-called pop-up type sheet laminate), or multiple sheets S can be simply laminated.

[0032] Furthermore, the dimensions of the sheet S (sheet laminate 20) can be such that the length L2 in the longitudinal direction (X direction) of the packaging bag 10 is approximately 150 to 250 mm, the width W2 in the width direction (Y direction) perpendicular to the longitudinal direction (X direction) of the packaging bag 10 is approximately 70 to 150 mm, and the height H2 in the height direction (Z direction) is approximately 20 to 100 mm (see Figures 2 and 3). Such a laminate of thin paper can be manufactured, for example, by a rotary type or multi-stand type interfolder.

[0033] The form of sheet S is not particularly limited and can be applied to, for example, sanitary tissue paper such as paper towels, kitchen paper, tissue paper, and toilet paper. These sanitary tissue papers also include sanitary tissue paper containing moisturizing ingredients (for example, lotion tissues).

[0034] Furthermore, the use of sheet S is not particularly limited and can be applied to industrial, household, or portable use. Among these, household and portable paper towels are preferably used as the sheet in this embodiment.

[0035] The number of plies in sheet S is not particularly limited, but can be one or more, preferably one ply or two plies (two layers). The shape of sheet S is also not particularly limited, but for example, it is preferable that the contour shape of a two-ply sheet when folded is rectangular (square, etc.).

[0036] The material of sheet S is not particularly limited, but for example, sheets of paper, nonwoven fabric, or cloth can be used, and paper (paper sheet) is preferred. When sheet S is a paper sheet, base paper made mainly from pulp is used. The pulp composition can be any known composition for paper sheets. For example, the pulp blending ratio can be 50% by mass or more, preferably 90% by mass or more, and more preferably 100% by mass.

[0037] Furthermore, the pulp composition in the sheet S (paper sheet) is not particularly limited. For example, softwood pulp such as NBKP (softwood kraft pulp) or NUKP (unbleached softwood pulp) and hardwood pulp such as LBKP (hardwood kraft pulp) or LUKP (unbleached hardwood pulp) can be used in any ratio.

[0038] In sheet S (paper sheet), the ratio of hardwood pulp to softwood pulp is not limited, but is preferably 10:90 to 80:20, and more preferably a pulp composition in which softwood pulp is more abundant than hardwood pulp. Furthermore, recycled paper pulp may be used in the pulp contained in sheet S (paper sheet).

[0039] The basis weight of sheet S is not particularly limited, but depending on the number of plies, it is 5 g / m² in the case of paper. 2 More than 80g / m 2 The following is preferable: 10 g / m² 2More than 60g / m 2 More preferably 10 g / m 2 More than 45g / m 2 The following applies. Also, for nonwoven fabrics, the weight is 20g / m². 2 More than 100g / m 2 The following are preferred. The basis weight will be measured in accordance with the provisions of JIS P 8124 (2011).

[0040] Furthermore, the thickness of the sheet S (paper sheet) is not particularly limited, and the paper thickness measured under the conditions of JIS P 8111 (1998) can be used. For example, if the sheet S is paper, the paper thickness is 50 μm or more and 600 μm or less per 2 plies, preferably 60 μm or more and 500 μm or less, and more preferably 130 μm or more and 400 μm or less.

[0041] Furthermore, the sheet S (paper sheet) may be embossed. Such embossing can be carried out by known embossing methods.

[0042] The form of the packaging bag 10 is not particularly limited. In this embodiment, it has a top surface 11, a bottom surface 12, a side surface 13, a side surface 14, an end surface 15, and an end surface 16. In the packaging bag 10, the top surface 11 and the bottom surface 12 face each other in the vertical direction (Z direction), the side surfaces 13 and 14 face each other in the width direction (Y direction), and the end surfaces 15 and 16 face each other in the longitudinal direction (X direction). In addition, the end surfaces 15 and 16 are continuous with any of the top surface 11, bottom surface 12, side surface 13, and side surface 14 (Figures 1, 3 to 8).

[0043] The dimensions of the packaging bag 10 are not particularly limited. For example, the length L1 in the longitudinal direction (X direction) of the packaging bag 10 can be about 150 to 250 mm, the width W1 in the width direction (Y direction) perpendicular to the longitudinal direction (X direction) of the packaging bag 10 can be about 70 to 150 mm, and the height H1 in the height direction (Z direction) can be about 20 to 100 mm (Figures 1 and 3). Note that the dimensions of the packaging bag 10 are shown with the sheet laminate 20 contained inside the packaging bag 10 (Figures 1 and 2).

[0044] The top surface 11 of the packaging bag 10, the top surface 11 side of the end surface 15, and the top surface 11 side of the end surface 16 have openings that extend in the longitudinal direction (X direction) of the packaging bag 10. Specifically, the openings have tear lines 30. The tear lines 30 are lines in which cuts C and ties T (two cuts C and an uncut portion between C) are arranged alternately, and when a tie T is broken, the adjacent cuts C become a continuous cut (Figures 1, 3, 7, and 8).

[0045] In this embodiment, the tearing line 30 constitutes a straight perforation M in which cuts C and ties T are arranged alternately (Figures 1, 3, 7, and 8). The ratio of ties T to cuts C in the tearing line 30 (perforation) is arbitrary, but can be, for example, 1:1 to 1:7, preferably 1:1.3 to 1:5, and more preferably 1:1.5 to 3.

[0046] In the packaging bag 10 of this embodiment, when the tearing line 30 (perforation M) is torn, an opening (opening OP) is formed on the top surface 11 of the packaging bag 10 from which the sheet S is pulled out (Figures 1 and 10).

[0047] The method for creating the tear-off line 30 is arbitrary. For example, although not shown in the diagram, the base material BS of the packaging bag 10, which will be described later, can be placed between the needle part and the base part, and the tip of the needle part can be inserted toward the receiving groove of the base part to form the tear-off line 30.

[0048] The packaging bag 10 may have ventilation holes (not shown). These ventilation holes can function as air holes in the packaging bag 10. The location of the ventilation holes is not particularly limited, and in this embodiment, ventilation holes can be provided on the sides 13, 14, end faces 15, and 16 of the packaging bag 10. The number of ventilation holes is not limited. The shape of the ventilation holes is also not limited, for example, they are circular in plan view. Furthermore, the dimensions of the ventilation holes are not limited, for example, they have a diameter of about 2 mm.

[0049] The method for creating the ventilation holes is arbitrary. For example, similar to the tearing cut line 30 described above, the base material BS of the packaging bag 10 can be placed between the needle portion and the base portion, and the tip of the needle portion can be inserted towards the receiving groove of the base portion to form the ventilation holes. When forming ventilation holes, a bag without a receiving groove in the base portion may be used.

[0050] By providing such ventilation holes in the packaging bag 10, the packaging bag becomes less likely to burst during storage or transportation of the sheet packaging 100.

[0051] The packaging form of the packaging bag 10 is not particularly limited. For example, the base material BS of the packaging bag 10 may be processed into a cylindrical shape and the open end of the cylindrical base material BS may be sealed (pillow packaging bag), the ends of the cylindrical packaging bag 10 sheet may be folded and sealed (caramel packaging bag), or a combination of these may be used. In the case of pillow packaging bags, the cylindrical base material BS may be folded into a gusset shape.

[0052] In this embodiment, the packaging bag 10 is a pillow packaging bag having at least one seal portion. Specifically, seal portions (end seals) 40 and 50 are formed on the end faces 15 and 16 of the packaging bag 10, and a seal portion (bottom seal) 60 is formed on the bottom face 12 of the packaging bag 10, so that the sheet S (sheet laminate 20) is pillow packaged.

[0053] In the packaging bag 10 of this embodiment, the sealing portions 40, 50, and 60 are heat-sealed. Here, heat sealing refers to heating a portion of the base material BS to weld portions of the packaging bag sheet together. Specifically, with the inner layer (resin layer) 10B of the base material BS (described later) positioned inside the packaging bag 10, the sealing portions 40, 50, and 60 are heat-sealed.

[0054] In the packaging bag 10, the joining pitch of the sealing portion 40, the joining pitch of the sealing portion 50, and the joining pitch of the sealing portion 60 are preferably 0.5 mm to 2 mm, more preferably 0.8 mm to 1.8 mm, and even more preferably 1.0 mm to 1.5 mm.

[0055] Here, the joining pitch refers to the spacing in a predetermined direction (for sealing portions 40, 50, and 60, the width direction (Y direction) of the packaging bag 10, and for sealing portion 60, the longitudinal direction (X direction) of the packaging bag 10) of the convex-shaped bonded portion (not shown) when viewed from one side of the sealing portion 40, 50, and 60 (for example, the bottom surface 12 side of the packaging bag 10).

[0056] In this embodiment, as described above, by setting the joining pitch of the sealing portions (sealing portions 40, 50, 60) to 0.5 mm or more and 2 mm or less, the adhesive function of the inner layer (resin layer 10B) provided on the base layer (paper layer) 10A, which will be described later, can be enhanced, and a packaging bag 10 (pillow packaging bag) with higher sealing performance can be obtained.

[0057] The packaging bag 10 is made of a base material BS containing a paper component. Here, the paper component is made of plant fibers bonded together (pulp). The pulp composition in the paper component is not limited; for example, the ratio of hardwood pulp to softwood pulp is 0:100 to 70:30, and preferably the pulp composition has a higher proportion of softwood pulp than hardwood pulp. Recycled paper pulp may also be used as the pulp.

[0058] The base material BS constituting the packaging bag 10 of the first embodiment consists of a base layer 10A, an inner layer 10B, and an outer layer 10C. The base material BS in the first embodiment has a three-layer structure in which the inner layer 10B and the outer layer 10C are laminated on each surface of the paper layer 10A (Figure 9).

[0059] The base layer 10A constitutes the base of the substrate BS. The base layer 10A also constitutes a paper layer containing the aforementioned paper components.

[0060] The material of the paper component contained in the base layer (paper layer) 10A is not particularly limited, and may be formed of, for example, kraft paper or rayon paper.

[0061] Here, kraft paper is paper made from kraft pulp as a raw material. Rayon paper is obtained by blending rayon fibers chemically synthesized from wood pulp or the like into kraft pulp. From the viewpoint of achieving both softness and strength of the packaging bag 10, rayon paper preferably has a rayon fiber blending ratio of 20% or less by mass ratio.

[0062] The basis weight of the base layer (paper layer) 10A is not limited, but is preferably 10 g / m 2 or more and 70 g / m 2 or less, more preferably 15 g / m 2 or more and 60 g / m 2 or less, still more preferably 20 g / m 2 or more and 50 g / m 2 or less. The basis weight is measured in accordance with the provisions of JIS P 8124 (2011).

[0063] The thickness of the base layer (paper layer) 10A is not limited, but for example, it is preferably 20 µm or more and 300 µm or less, more preferably 30 µm or more and 200 µm or less, and still more preferably 40 µm or more and 180 µm or less. The thickness is measured in accordance with the provisions of JIS P 8118 (2014).

[0064] The tensile strength of the base layer (paper layer) 10A is not limited, but for example, it is 500 cN / m or more and 20000 cN / m or less in the machine direction of fibers (flow direction or MD direction), preferably 1000 cN / m or more and 15000 cN / m or less, more preferably 1500 cN / m or more and 12000 cN / m or less.

[0065] Furthermore, the tensile strength in the transverse direction of the fiber (direction perpendicular to the flow direction or CD direction) is 100 cN / m or more and 10,000 cN / m or less, preferably 300 cN / m or more and 5,000 cN / m or less, more preferably 500 cN / m or more and 2,500 cN / m or less. The tensile strength is measured in accordance with the provisions of JIS P 8113 (2006).

[0066] The elongation of the base layer (paper layer) 10A is not limited, but for example, it is 0.5% to 30% in the longitudinal direction of the fibers (MD direction), preferably 1% to 25%, and more preferably 2% to 20%. In the transverse direction of the fibers (CD direction), it is 0.5% to 20%, 1% to 10%, and 2% to 5%. The elongation is measured in accordance with the provisions of JIS P 8113 (2006).

[0067] The tear strength of the base layer (paper layer) 10A is not limited, but for example, it is 50 mN or more and 500 mN or less in the longitudinal direction of the fibers (MD direction), preferably 80 mN or more and 480 mN or less, more preferably 100 mN or more and 450 mN or less.

[0068] Furthermore, the tear strength in the transverse direction (CD direction) of the fiber is 200 mN to 1000 mN, preferably 250 mN to 900 mN, more preferably 300 mN to 800 mN. The tear strength is measured in accordance with the provisions of JIS P 8116 (2000).

[0069] The inner layer 10B is laminated to either side of the base layer (paper layer) 10A and constitutes a resin layer containing a thermoplastic resin. The inner layer 10B constitutes the inner surface IS of the base material BS, which is placed on the inside of the packaging bag 10 (the side on which the inner layer 10B of the base material BS is formed). The inside of the packaging bag 10 corresponds to the side in which the sheet S is contained within the packaging bag 10, and the inner surface IS of the base material BS, which is placed on the inside of the packaging bag 10, corresponds to the side of the base material BS that is in contact with the sheet S contained within the packaging bag 10.

[0070] The thermoplastic resin contained in the inner layer (resin layer) 10B is not particularly limited in material, but is preferably low-density polyethylene. The low-density polyethylene can be either high-pressure low-density polyethylene (LDPE) or linear low-density polyethylene (L-LDPE).

[0071] The thickness of the inner layer (resin layer) 10B is not limited, but is preferably 5 μm to 40 μm, more preferably 7 μm to 35 μm, and even more preferably 9 μm to 30 μm. The paper thickness is measured in accordance with the provisions of JIS P 8118 (2014).

[0072] The thermoplastic resin contained in the inner layer (resin layer) 10B contains a slip agent. Here, the slip agent is an agent that reduces the coefficient of friction of the surface (inner surface) of the inner layer 10B. In this embodiment, the slip agent is added to the thermoplastic resin contained in the inner layer (resin layer) 10B, but it may also be coated onto the inner surface IS of the base material BS.

[0073] The components of the slip agent are not particularly limited, but for example, ethylene homopolymers, fatty acid amides, vegetable oils, etc., can be used as the main components. The amount of slip agent relative to the thermoplastic resin is not particularly limited. In addition to the main components, the slip agent may also contain additives depending on the purpose, such as maintaining the stability of the slip agent.

[0074] The outer layer (printed layer) 10C is provided on either the other side of the paper layer 10A and constitutes the printed layer that is printed on the surface of the packaging bag. The outer layer (printed layer) 10C constitutes the outer surface OS of the base material BS that is placed on the outside of the packaging bag 10. The outer surface OS of the base material BS that is placed on the outside of the packaging bag 10 constitutes the side that does not come into contact with the sheet S contained in the packaging bag 10.

[0075] The outer layer (printed layer) 10C contains a grip agent. Here, the grip agent is an agent that increases the coefficient of friction of the surface (outer surface) of the outer layer 10C. In this embodiment, the grip agent is coated on the outer surface OS of the substrate BS, but it may also be included in the outer layer (printed layer) 10C.

[0076] The components of the grip agent are not particularly limited, but for example, medium ink (synthetic resin), oil-based varnish, etc., can be used as the main component. The amount of grip agent used relative to the outer layer (printed layer) 10C is not particularly limited. In addition to the main component, the grip agent may also contain auxiliary agents and solvents as needed to maintain the stability of the grip agent.

[0077] In this embodiment, the proportion of paper components in the packaging bag 10 (base material BS) is 50% or more.

[0078] The basis weight of the packaging bag 10 (base material BS) is not limited, but is preferably 20 g / m². 2 More than 100g / m 2 The following is more preferable: 25 g / m² 2 More than 70g / m 2 More preferably 30 g / m 2 More than 60g / m 2 The following applies. Note that basis weight is measured in accordance with the provisions of JIS P 8124 (2011).

[0079] The thickness (paper thickness) of the packaging bag 10 (base material BS) is not limited, but for example, it is 25 μm or more and 350 μm or less, preferably 30 μm or more and 250 μm or less, and more preferably 45 μm or more and 200 μm or less. The thickness may be the thickness measured in accordance with the provisions of JIS P 8118 (2014).

[0080] The tensile strength of the packaging bag 10 (base material BS) is not limited, but for example, it is 1000 cN / m or more and 20000 cN / m or less in the longitudinal direction of the fibers (MD direction), preferably 1500 cN / m or more and 18000 cN / m or less, more preferably 2000 cN / m or more and 15000 cN / m or less.

[0081] Furthermore, the tensile strength in the transverse direction (CD direction) of the fiber is 500 cN / m or more and 10,000 cN / m or less, preferably 1,000 cN / m or more and 8,000 cN / m or less, more preferably 1,500 cN / m or more and 5,000 cN / m or less. The tensile strength is measured in accordance with the provisions of JIS P 8113 (2006).

[0082] The elongation of the packaging bag 10 is not limited, but for example, it is 0.5% to 30% in the longitudinal direction of the fibers (MD direction), preferably 1% to 25%, and more preferably 2% to 20%. In the transverse direction of the fibers (CD direction), it is 0.5% to 20%, 1% to 10%, and 2% to 5%. The elongation is measured in accordance with the provisions of JIS P 8113 (2006).

[0083] The tear strength of the packaging bag 10 is not limited, but for example, it is 50 mN or more and 500 mN or less in the longitudinal direction of the fibers (MD direction), preferably 80 mN or more and 450 mN or less, more preferably 100 mN or more and 400 mN or less.

[0084] Furthermore, the tear strength in the transverse direction (CD direction) of the fiber is 200 mN to 1000 mN, preferably 250 mN to 900 mN, more preferably 300 mN to 800 mN. The tear strength is measured in accordance with the provisions of JIS P 8116 (2000).

[0085] The tapered stiffness of the packaging bag 10 is not limited, but for example, it is 0.01 mN / m or more and 0.2 mN / m or less in the longitudinal direction of the fibers (MD direction), preferably 0.02 mN / m or more and 0.17 mN / m or less, and more preferably 0.03 mN / m or more and 0.15 mN / m or less.

[0086] Furthermore, the Taber stiffness in the transverse direction (CD direction) of the fiber is 0.001 mN / m or more and 0.1 mN / m or less, preferably 0.01 mN / m or more and 0.08 mN / m or less, and more preferably 0.02 mN / m or more and 0.07 mN / m or less. The Taber stiffness is measured in accordance with the provisions of JIS P 8125 (2000).

[0087] In the packaging bag 10 of this embodiment, a first static friction coefficient A is generated between the inner surface IS of the base material BS (the inner surface IS on the side where the inner layer 10B of the base material BS is formed) and the sheet S (sheet laminate 20) which is placed inside the packaging bag 10. In addition, a second static friction coefficient B is generated between the outer surface OS of the base material BS (placed outside the packaging bag 10) and the artificial skin (not shown). The second static friction coefficient B is greater than the first static friction coefficient A, and the first static friction coefficient A is even less than 0.55.

[0088] Here, the static friction coefficient represents the ratio of the frictional force generated at the contact surface of two objects when they are not in relative motion to the force acting perpendicular to the contact surface. The static friction coefficient is measured in accordance with the provisions of JIS P 8147 (2010) horizontal method. Furthermore, artificial skin refers to a molded body made of urethane elastomer that mimics human skin.

[0089] In this embodiment, the base material BS of the packaging bag 10 includes a base layer 10A containing paper components and an inner layer 10B laminated on either side of the base layer 10A and positioned inside the packaging bag 10. The inner layer 10B contains a thermoplastic resin containing a slip agent, thereby reducing the static friction coefficient between the base material BS and the sheet S. As a result, the base material BS becomes more slippery against the sheet S, and if perforations M are provided in the paper packaging bag 10, the perforations M become easier to tear, making it easier to open the paper packaging bag 10 (Figures 1 and 10).

[0090] In this embodiment, the first static friction coefficient between the inner surface IS on the side where the inner layer 10B of the base material BS containing paper components is formed and the sheet S is present. A When the ratio is 0.55 or less, the inner surface of the paper-containing base material BS becomes slippery against the sheet S. As a result, the perforations M provided on the paper packaging bag 10 become easier to tear, making it easier to open the packaging bag 10 (Figures 1 and 10).

[0091] In this embodiment, the second static friction coefficient B between the outer surface OS of the base material BS, which is placed on the outside of the packaging bag 10, and the artificial skin is greater than the first static friction coefficient A on the inner surface IS of the base material BS. stomachAs a result, the inner surface IS of the base material BS becomes more slippery against the sheet S, and the outer surface OS of the base material BS becomes less slippery against the artificial skin. Therefore, the perforations M provided on the paper packaging bag 10 become easier to tear, making it even easier to open the packaging bag 10 (Figures 1 and 10).

[0092] In the packaging bag 10 of this embodiment, it is preferable that the ratio of the first static friction coefficient A to the second static friction coefficient B is 0.65 or less. Here, the ratio of the first static friction coefficient A to the second static friction coefficient B represents the ratio of the first static friction coefficient A to the second static friction coefficient.

[0093] In this embodiment, by setting the ratio of the first static friction coefficient A to the second static friction coefficient B to 0.65 or less, the difference between the friction coefficient of the inner surface IS side of the base material BS against the sheet S contained in the packaging bag 10 and the friction coefficient of the outer surface OS side of the base material BS against the artificial skin (not shown) becomes larger. As a result, the perforations M provided in the paper packaging bag 10 become easier to tear, making it easier to open the packaging bag 10.

[0094] In the packaging bag 10 of this embodiment, the second static friction coefficient B However, it is preferable that it be 1.1 or less. In the case of paper packaging bags, the first static friction coefficient is important in terms of improving ease of opening. A and the second Silence The difference from the coefficient of friction should be as large as possible. On the other hand, the first static friction coefficient A Against the second Silence If the coefficient of friction becomes too high, the perforations on the paper packaging bag may tear before the packaging bag is opened (for example, during the manufacturing, distribution, or storage of the sheet packaging body 100 using the packaging bag 10).

[0095] Therefore, in this embodiment, by setting the second static friction coefficient B to 1.1 or less, the second static friction coefficient B is adjusted so that the outer surface OS of the base material BS does not become too slippery, thereby preventing the packaging bag 10 from unexpectedly tearing without reducing its ease of opening.

[0096] In the packaging bag 10 of this embodiment, the first static friction coefficient A corresponds to the static friction coefficient between the CD direction of the base material BS and the MD direction of the sheet S. The second static friction coefficient B corresponds to the static friction coefficient between the CD direction of the base material BS and the artificial skin.

[0097] In this embodiment, the MD direction of the base material BS corresponds to the longitudinal direction (X direction) of the packaging bag 10, and the CD direction of the base material BS corresponds to the width direction (Y direction) of the packaging bag 10 (Figures 1, 3 to 8). Also, the MD direction of the sheet S corresponds to the width direction (Y direction) of the packaging bag 10 or the sheet laminate 20, and the CD direction of the sheet S corresponds to the longitudinal direction (X direction) of the packaging bag 10 or the sheet laminate 20 (Figures 1 and 2).

[0098] In this embodiment, by setting the static friction coefficient between the CD direction of the base material BS and the MD direction of the sheet S as the first static friction coefficient A, the CD direction of the base material BS becomes more slippery relative to the MD direction of the sheet S. B This makes it less likely for the artificial skin to slip relative to the CD direction of the base material BS.

[0099] In this embodiment, when the sheet S is placed in the packaging bag 10 such that the MD direction of the sheet S is aligned with the CD direction of the base material BS, and perforations M are formed in the MD direction of the base material BS, the perforations M are opened by pressing down on the surface of the packaging bag 10 with the perforations M (top surface 11) with both thumbs and moving the thumbs away from each other in the CD direction of the base material BS (Figures 1 and 10). At this time, the perforations are opened easily with little force, making it even easier to open the packaging bag 10 (top surface 11).

[0100] In the packaging bag 10 of this embodiment, as described above, a tear-off line 30 (perforation M) is formed on the top surface 11 of the packaging bag 10, along the MD direction of the base material BS.

[0101] In this embodiment, by forming a tear-off line 30 (perforation M) along the MD direction of the base material BS on the top surface 11 of the packaging bag 10, the tear-off line 30 (perforation M) can be easily opened by simply pressing the top surface 11 of the packaging bag 10 with both thumbs and moving the thumbs away from each other in the CD direction of the base material BS.

[0102] Furthermore, in this embodiment, the opened tear line 30 (perforation M) can form a sheet dispensing opening (opening OP) formed on the top surface 11 of the packaging bag 10 (Figures 1 and 10). As a result, the sheet S can be removed from the top surface 11 of the packaging bag 10.

[0103] In this embodiment, the tearing lines 30 (perforations M) are formed along the MD direction of the base material BS and the CD direction of the sheet S, and the static friction coefficient is measured in a direction perpendicular to the direction in which the perforations M extend (the CD direction of the base material BS and the MD direction of the sheet S). However, the orientation of the sheet S and base material BS for measuring the static friction coefficient is not limited. For example, the tearing lines 30 (perforations M) may be formed along the CD direction of the base material BS and the MD direction of the sheet S, and the static friction coefficient may be measured in a direction perpendicular to the direction in which the perforations M extend (the MD direction of the base material BS and the CD direction of the sheet S).

[0104] Furthermore, in this embodiment, as described above, the case in which the sheet S is placed in the packaging bag 10 so that the MD direction of the sheet S is aligned with the CD direction of the base material BS has been described. However, the relationship between the MD direction of the sheet S and the CD direction of the base material BS is not limited. In other words, the direction in which the sheet S is placed in the packaging bag 10 is not limited. For example, the sheet S may be placed in the packaging bag 10 so that the MD direction of the sheet S is aligned with the MD direction of the base material BS.

[0105] Figure 12 shows a cross-section of the base material of the packaging bag according to the second embodiment. In the second embodiment shown in Figure 12, parts that are common with the first embodiment shown in Figure 9 are denoted by the same reference numerals as in Figure 9 and their description is omitted.

[0106] The base material BS constituting the packaging bag 10 of the second embodiment consists of a base layer 10A and an inner layer 10B. The base material BS in the second embodiment has a two-layer structure in which the inner layer 10B is laminated on one side of the paper layer 10A (Figure 12).

[0107] In the packaging bag 10 of the second embodiment, the outer layer 10C is not laminated on the other side of the paper layer 10A. However, similar to the first embodiment, the first static friction coefficient A generated between the inner surface IS of the base material BS located inside the packaging bag 10 and the sheet S (sheet laminate 20) is smaller than the second static friction coefficient B generated between the outer surface OS of the base material BS located outside the packaging bag 10 and the artificial skin (not shown). The first static friction coefficient A is further reduced to 0.55 or less. As a result, in the second embodiment, similar to the first embodiment, the inner surface IS of the base material BS becomes slippery against the sheet S contained in the packaging bag 10, and the outer surface OS of the base material BS becomes less slippery against artificial skin (not shown). Therefore, in the second embodiment as well, if perforations M are provided in the paper packaging bag 10, the perforations M become easier to tear, making it easier to open even a paper packaging bag (Figures 1 and 10).

[0108] Furthermore, in the packaging bag 10 of the second embodiment, the ratio of the first static friction coefficient A to the second static friction coefficient B is 0.65 or less. As a result, in the second embodiment as well, the difference between the friction coefficient of the inner surface IS side of the base material BS against the sheet S contained in the packaging bag 10 and the friction coefficient of the outer surface OS side of the base material BS against the artificial skin (not shown) can be made larger. Therefore, the perforations M provided in the paper packaging bag 10 become easier to tear, making it easier to open the packaging bag 10.

[0109] The sheet packaging 100 of this embodiment can use the packaging bag 10 described above. Specifically, the sheet packaging 100 comprises a packaging bag (packaging bag of the first embodiment) 10 and a sheet S contained in the packaging bag 10 (Figures 1 and 2).

[0110] The sheet packaging 100 of this embodiment is configured as a sheet packaging in which a sheet S is contained in the packaging bag 10 described above, thereby achieving the same effects as the packaging bag 10 described above. That is, in the sheet packaging 100 of this embodiment, even if the packaging bag 10 constituting the sheet packaging 100 is made of paper, the perforations M provided on the paper packaging bag 10 become easier to tear, making it easy to open even if the packaging bag is made of paper (Figures 1 and 10).

[0111] In the packaging bag 10 of this embodiment, as described above, an inner layer (resin layer) 10B containing thermoplastic resin is provided on either side of the base layer (paper layer) 10A containing paper components, which softens the texture of the packaging bag 10. This suppresses the stiffness of the packaging bag 10 and gives it flexibility. Therefore, even if the material of the packaging bag is changed from resin to paper, it is possible to provide a packaging bag 10 that is less likely to break during manufacturing or transportation.

[0112] Furthermore, in this embodiment, the packaging bag 10, which is provided with conformability by laminating the inner layer (resin layer) 10B onto the base layer (paper layer) 10A, is provided with a tear line 30, making it easy to tear the tear line 30.

[0113] Furthermore, in this embodiment, since the inner layer (resin layer) 10B provided on either side of the base layer (paper layer) 10A contains a thermoplastic resin, when the inner layer (resin layer) 10B is heated when sealing (or sealing) the packaging bag 10, the melted inner layer (resin layer) 10B can function as an adhesive (has adhesive function), making it easy to seal the packaging bag 10.

[0114] Furthermore, in this embodiment, since the proportion of paper components in the packaging bag 10 is 50% or more, the environmental impact can be reduced.

[0115] In this embodiment, as described above, by setting the thickness of the inner layer (resin layer) 10B to 5 μm or more and 40 μm or less, it becomes easier to maintain a paper component ratio of 50% or more in the packaging bag. Furthermore, it is possible to maintain the adhesive function of the inner layer (resin layer) 10B when sealing the packaging bag while suppressing the stiffness of the packaging bag.

[0116] In this embodiment, as described above, by using low-density polyethylene as the thermoplastic resin contained in the inner layer (resin layer) 10B, it is possible to further suppress the stiffness of the packaging bag 10 while improving the adhesive function of the inner layer (resin layer) 10B when sealing the packaging bag 10.

[0117] In this embodiment, as described above, the packaging bag 10 is a pillow packaging bag, and with the inner layer (resin layer) 10B positioned inside the packaging bag 10, at least one sealing portion is heat-sealed to bond the resin layers together. This allows the adhesive function of the inner layer (resin layer) 10B to be effectively utilized, resulting in a highly sealed packaging bag 10.

[0118] In this embodiment, by providing a tear line 30 on the packaging bag 10, the packaging bag 10 can be opened simply by tearing the tear line 30. Furthermore, the torn tear line 30 can form an opening (opening OP) of the packaging bag 10. Moreover, in this embodiment, since the tear line 30 is provided on the packaging bag 10, which is given flexibility by laminating an inner layer (resin layer) 10B on a paper layer 10A, the tear line 30 is easy to tear. [Examples]

[0119] The present invention will be described in more detail below with reference to examples. The examples and comparative examples were evaluated by the following tests.

[0120] [Test specimen] As a test specimen, a sheet package 100 was prepared in which multiple sheets S (sheet laminate 20) were pillow-packed in a paper packaging bag 10 (Figures 1 to 8).

[0121] The packaging bag 10 is made of a base material BS, which consists of a base layer 10A, an inner layer 10B, and an outer layer 10C (Figure 9). The inner layer 10B is made of low-density polyethylene (PE). The outer layer 10C is a gravure printed layer. On the top surface 11 of the packaging bag 10, a tear-off cut line 30 (perforation line M) is formed, extending from the seal portion 40 to the seal portion 50 in the longitudinal direction (MD direction) of the packaging bag 10. The ratio of tie T to cut C of the perforation line M was 1:2 in the example and 1:5 in the comparative example.

[0122] The sheet laminate 20 is a paper towel in which sheets S are laminated in a folded state, and is a single (1-ply) paper towel (product name "Elveil Paper Towel Eco Dry (medium size)", manufactured by Daio Paper Corporation, 200 sheets, height H1: 65 mm, length L1: 210 mm, width (depth) W1: 115 mm, basis weight 33 g / m²). 2 (Paper thickness 180μm) and double-ply paper towels (product name "Elleair Paper Towel Smart Type Double (Medium Size)", manufactured by Daio Paper Corporation, 200 sheets, height H1: 60mm, length L1: 210mm, width (depth) W1: 115mm, basis weight 16g / m²) 2 (×2) was used.

[0123] [Yonetsubo] The basis weight (grammage) of the base material (all layers) BS and base layer 10A of the packaging bag 10 in the test specimen (sheet packaging 100) was measured in accordance with the provisions of JIS P 8124 (2011). The unit of basis weight is g / m². 2 That is the case.

[0124] [Paper thickness] The paper thickness of the base material (all layers) BS and base layer 10A of the packaging bag 10 in the test specimen (sheet packaging 100) was measured using an ISO paper thickness gauge (CITIZEN, MEI-11) in accordance with the provisions of JIS P 8118 (2014). The unit of thickness is μm.

[0125] [Tensile strength] The tensile strength (mN) in the longitudinal (MD direction) and transverse (CD direction) directions was measured for the base material (all layers) BS and base layer 10A of the packaging bag 10 in the test specimen (sheet packaging 100) using a Tensilon universal tester (manufactured by A&D, RTG-1210) in accordance with the provisions of JIS P 8113 (2006).

[0126] [stretch] For the base material (all layers) BS and base layer 10A of the packaging bag 10 in the test specimen (sheet packaging 100), the elongation (%) in the longitudinal direction (MD direction) and transverse direction (CD direction) was measured using a Tensilon universal tester (manufactured by A&D, RTG-1210) in accordance with the provisions of JIS P 8113 (2006).

[0127] [Tear strength] For the base material (all layers) BS and base layer 10A of the packaging bag 10 in the test specimen (sheet packaging 100), the tear strength in the longitudinal direction (MD direction) and transverse direction (CD direction) of the fibers was measured using a tear strength tester (Kumagai Riki Kogyo Co., Ltd., Elmendorf tear strength tester (digital display type)) in accordance with the provisions of JIS P 8116 (2000).

[0128] [Taber stiffness] The Taber stiffness of the base material (all layers) BS of the packaging bag 10 in the test specimen (sheet packaging 100) was measured in accordance with the provisions of JIS P 8125 (2000). A Taber stiffness tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used to measure the Taber stiffness.

[0129] [Coefficient of static friction] The static friction coefficient was measured in accordance with the provisions of JIS P 8147 (2010) horizontal method. A load cell tensile testing machine (Shimadzu Corporation, AGS-500B) was used to measure the static friction coefficient.

[0130] Specifically, the static friction coefficients A1 between the CD direction of the inner surface IS (inner layer 10B) of the base material BS of the packaging bag 10 and the MD direction of the sheet S (web single) were measured in the test specimen (sheet packaging 100). The static friction coefficients A2 between the CD direction of the inner surface IS (inner layer 10B) of the base material BS of the packaging bag 10 and the MD direction of the sheet S (web double) were also measured. The static friction coefficient B between the CD direction of the outer surface OS (outer layer 10C) of the base material BS of the packaging bag 10 and the artificial skin (BioSkin Plate, No. 132#BSC, manufactured by Viewlux, Inc., made of thermoplastic urethane elastomer) were also measured.

[0131] In measuring the static friction coefficients A1 and A2, the base material BS was fixed to the horizontal plate side of the friction tester so that the CD direction of the inner surface (inner layer 10B) of the base material BS was facing outwards, and the sheet S was fixed to the weight side of the friction tester so that the MD direction of the surface of the sheet S was facing outwards.

[0132] In measuring the static friction coefficient B, the base material BS was fixed to the horizontal plate side of the friction tester so that the CD direction of the outer surface OS (outer layer 10C) of the base material BS was facing outwards. The artificial skin was cut from a piece measuring 100 mm (length) x 100 mm (width) x 5 mm (thickness) to fit the weight side of the friction tester, and attached to the weight side of the friction tester so that the measurement surface was facing outwards (the non-glossy side).

[0133] If the dimensions of the test specimens are insufficient, they may be joined together using a paper-based sealing material on one side of the back (the side not to be measured). In this case, care should be taken to prevent wrinkles or sagging.

[0134] [Ease of opening perforations] The ease of opening the perforations M (tear lines 30) formed on the top surface 11 of the packaging bag 10 in the test specimen (sheet packaging 100) was confirmed. The test was conducted for both cases: when the packaging bag 10 contained a single-type sheet S (web) and when it contained a double-type paper towel sheet. The ease of opening the perforations on the sheet packaging 100 was evaluated when 10 users pressed down on the side of the packaging bag 10 with the perforations M (top surface 11) with both thumbs and moved their thumbs away from each other in the CD direction of the base material BS. If 0 to 3 people answered that it was difficult to open, it was evaluated as ○ (good), and if 4 or more people answered as × (poor). The evaluation criteria are as follows. A: Perforations M are prone to tearing. B: Perforation M can be opened. C: The perforations cannot be torn, or they can be torn but are difficult to tear.

[0135] Examples and comparative examples will be described below.

[0136] [Example 1] When a slip agent was added to the inner layer 10B of the base material BS of the packaging bag 10, and a grip agent (varnish) was applied to the outer layer 10C, the static friction coefficient A1 was 0.42, the static friction coefficient A2 was 0.38, and the static friction coefficient B was 0.96, the ease of opening the perforations was A for both single and double perforations. The conditions of the packaging bag 10, the conditions of the sheet (web), and the evaluation results (static friction coefficient and ease of opening the perforations) are shown in Table 1.

[0137] [Example 2] Except for the static friction coefficients A1 (0.46), A2 (0.45), and B (0.95), the evaluation was the same as in Example 1, and the ease of opening the perforations was B for both single and double perforations. The conditions for packaging bag 10, the conditions for sheet (web), and the evaluation results are shown in Table 1.

[0138] [Example 3] Except for the static friction coefficients A1 (0.41), A2 (0.37), and B (0.8), the evaluation was the same as in Example 1, and the ease of opening the perforations was A for both single and double perforations. The conditions for packaging bag 10, the conditions for sheet (web), and the evaluation results are shown in Table 1.

[0139] [Comparative Example 1] When no slip agent was added to the PE used in the inner layer 10B of the base material BS of the packaging bag 10, and no grip agent (varnish) was applied to the outer layer 10C, the static friction coefficient A1 was 0.57, the static friction coefficient A2 was 0.69, and the static friction coefficient B was 1.2, the ease of opening the perforations was C for both single and double perforations. The conditions for the packaging bag 10, the sheet (web) conditions, and the evaluation results are shown in Table 1.

[0140] [Reference example 1] A sheet packaging was prepared in which multiple sheets S (sheet laminate 20) were pillow-packed in a resin film packaging bag. When the static friction coefficient A1 was 0.3, the static friction coefficient A2 was 0.27, and the static friction coefficient B was 1.14, the ease of opening the perforations was A for both single and double perforations. The conditions of the packaging bag, the conditions of the sheet (web), and the evaluation results are shown in Table 1.

[0141] [Table 1]

[0142] As shown in Table 1, test specimens in which the base material BS includes a base layer 10A containing paper components and an inner layer 10B laminated on one side of the base layer 10A and placed inside the packaging bag 10, and in which the inner layer 10B contains a thermoplastic resin containing a slip agent, showed good ease of opening the perforations (Examples 1-3).

[0143] In contrast, the test specimen containing a thermoplastic resin without a slip agent in the inner layer 10B of the base material BS exhibited poor perforation (Comparative Example 1).

[0144] In other words, this embodiment is a packaging bag that contains a sheet and is made of a base material containing paper components, and the base material has at least a tear line formed thereon for removing the sheet from the packaging bag. The coefficient of static friction between the outer surface of the base material and the fingers (or artificial skin) of a person tearing the tear line is greater than the coefficient of static friction between the inner surface of the base material and the sheet. Therefore, when tearing the tear line, the fingers will not slip, making it difficult to tear.

[0145] Furthermore, a substrate having such a static friction coefficient may be formed over the entire surface of the packaging bag, or it may be formed only on the surface where the tear-off line is formed (for example, the top surface of the packaging bag). In addition, it is possible to make the static friction coefficient between a person's fingers (or artificial skin) and a portion of the substrate that comes into contact with the fingers when tearing the tear-off line greater than the static friction coefficient between the inner surface of the substrate and the sheet.

[0146] Although embodiments of the present invention have been described above, the present invention is not limited to any particular embodiment, and various modifications and changes are possible within the scope of the invention as described in the claims. [Explanation of symbols]

[0147] 100-sheet package 10 packaging bags BS base material IS (Internal) OS external 10A base layer (paper layer) 10B Inner layer (resin layer) 10C Outer layer (printing layer) 11 Top surface 12. Base 13, 14 Side view 15, 16 End faces 20-sheet laminate S Seat 30 Cleavage score line M perforation OP outlet (opening) 40, 50 sealing section (end seal) 60. Seal section (bottom seal) L1, L2 Length W1, W2 width H1, H2 Height

Claims

1. A packaging bag for containing a sheet, Composed of a base material containing paper components, The aforementioned substrate is A base layer containing the aforementioned paper component, It includes an inner layer laminated on either side of the base layer and placed inside the packaging bag, The inner layer comprises a thermoplastic resin. The aforementioned thermoplastic resin contains a slip agent, A first static friction coefficient is present between the inner surface of the substrate on the side where the inner layer is formed and the sheet. The first static friction coefficient is 0.55 or less, A second static friction coefficient is present between the outer surface of the substrate, which is placed on the outside of the packaging bag, and the artificial skin. The preceding second static friction coefficient is greater than the preceding first static friction coefficient. The ratio of the first static friction coefficient to the second static friction coefficient is 0.65 or less. The first static friction coefficient is the static friction coefficient between the CD direction of the substrate and the MD direction of the sheet. The second static friction coefficient is the static friction coefficient between the substrate in the CD direction and the artificial skin. A tear line is formed on the top surface of the packaging bag, along the MD direction of the base material. packaging bag.

2. The second static friction coefficient is 1.1 or less. The packaging bag according to claim 1.

3. A packaging bag according to claim 1 or 2, The packaging bag contains a sheet, Sheet packaging.

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