Laminates for packaging bags and packaging bags

Abstract

To provide a laminate for a packaging bag which can improve pattern reproducibility and gas permeation prevention, and can suppress increase in a mass accompanied by the improvement.SOLUTION: A laminate for a packaging bag includes a sheet-like paper-made base material, a resin coat layer covering one surface of the base material, a seal layer covering a part of the other surface of the base material, and ink positioned on a surface opposite to the base material of the resin coat layer, wherein the mass of the resin coat layer is 5 mass% or more and 30 mass% or less with respect to the total mass of the base material and the resin coat layer, the seal layer has a pigment composed of at least one of a light-storing pigment and a fluorescent pigment, and the content of the pigment is 0.075 mass% or more and 5.5 mass% or less with respect to the mass of the seal layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to laminates for packaging bags and packaging bags. [Background technology]

[0002] Conventionally, packaging bags made from plastic films using PET (polyethylene terephthalate) or the like as a base material have been used. For example, Patent Document 1 below discloses a packaging bag containing a polyester laminate in which a gas barrier layer is laminated on a polyester base material. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2015-150807 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] In recent years, paper-based packaging bags have been increasingly used as an alternative to resin-based packaging bags, as exemplified in Patent Document 1 above. However, the pattern reproducibility and air permeability of paper-based packaging bags tend to be inferior to those of resin-based packaging bags. Therefore, improvements in pattern reproducibility and air permeability are required for paper-based packaging bags. However, an increase in the mass of the packaging bag due to improvements in pattern reproducibility and air permeability is undesirable.

[0005] One aspect of the present invention is to provide a laminate for packaging bags and a packaging bag using the same, which can improve pattern reproducibility and air permeability while suppressing the increase in mass associated with such improvements. [Means for solving the problem]

[0006] A laminate for a packaging bag according to one aspect of the present invention comprises a sheet-like paper substrate, a resin coating layer covering one side of the substrate, a sealing layer covering a portion of the other side of the substrate, and ink located on the side of the resin coating layer opposite to the substrate. The mass of the resin coating layer is 5% by mass or more and 30% by mass or less of the total mass of the substrate and the resin coating layer, and the sealing layer has a pigment composed of at least one of a phosphorescent pigment and a fluorescent pigment, with the pigment content being 0.075% by mass or more and 5.5% by mass or less of the mass of the sealing layer.

[0007] This laminate for packaging bags is sheet-like and comprises a resin coating layer covering one side of a paper base material, with the ink positioned on the resin coating layer. Therefore, compared to cases where ink is applied directly to the paper base material, the reproducibility of the design can be improved. Furthermore, the mass of the resin coating layer is 5% to 30% by mass of the total mass of the base material and the resin coating layer. This allows for improved air permeability of the laminate while suppressing an increase in mass. In addition, the sealing layer covers a portion of the other side of the base material and contains a pigment composed of at least one of a phosphorescent pigment and a fluorescent pigment, in a content of 0.075% to 5.5% by mass of the sealing layer's mass. This allows for accurate detection of the position of the sealing layer, which is provided on a portion of the base material. Therefore, for example, using the ink mark printed on the resin coating layer and the sealing layer, it is easy to determine whether there is a misalignment between the position of the design printed on the resin coating layer and the position of the sealing layer. In other words, it is easy to determine whether there is a registration error between the sealing layer and the ink. Therefore, it is possible to manufacture laminated packaging bags with a high yield while suppressing the increase in mass of the laminated packaging bags.

[0008] The basis weight of the above substrate is 30 g / m². 2 More than 170g / m 2 The following is acceptable: Basis weight of the base material is 30 g / m². 2 As a result of the above, damage to the base material is less likely to occur when forming the laminate for packaging bags into a bag shape, and the basis weight of the base material is 170 g / m². 2 As a result of the following, the laminate for packaging bags does not become too rigid, and a good bag shape can be formed.

[0009] The above resin coating layer may contain at least one selected from the group consisting of polyolefin resins, polyvinyl alcohol resins, and latex resins.

[0010] The mass of the resin coating layer may be 10% to 20% by mass of the total mass of the substrate and the resin coating layer. In this case, the air permeability can be further improved.

[0011] The Beck smoothness of the resin coating layer on the side opposite to the substrate may be between 350 seconds and 2000 seconds. In this case, the reproducibility of the image can be further improved.

[0012] The above-mentioned sealing layer may contain the above-mentioned pigment in an amount of 0.1% to 5% by mass relative to the mass of the sealing layer. When the pigment content is within this range, the position of the sealing layer provided on a part of the substrate can be detected with greater accuracy. In addition, the sealing performance of the sealing layer is more easily maintained.

[0013] The sealing layer may cover 5% to 70% of the other surface of the substrate. In this case, the amount of resin required to form the sealing layer can be further reduced, thereby suppressing an increase in the mass of the laminate for the packaging bag and preventing blocking.

[0014] The laminate for the packaging bag further comprises an overcoat layer covering the ink, and the thickness of the overcoat layer may be 5 μm or less. Because the laminate for the packaging bag includes a resin coating layer, even if the thickness of the overcoat layer is 5 μm or less, the overall air permeability of the laminate for the packaging bag is good. In addition, the amount of resin or the like used to form the overcoat layer can be reduced.

[0015] A packaging bag according to one aspect of the present invention comprises the above-mentioned laminate for packaging bags, wherein a portion of the sealing layer that overlaps in the thickness direction of the base material and another portion of the sealing layer that overlaps in the thickness direction of the base material are sealed. [Effects of the Invention]

[0016] According to one aspect of the present invention, it is possible to improve the pattern reproducibility and the air permeability prevention property, and to provide a laminate for a packaging bag capable of suppressing the mass increase accompanying the improvement and a packaging bag using the same.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view of a laminate for a packaging bag. [Figure 2] FIG. 2 is a schematic plan view of a packaging bag. [Figure 3] FIG. 3 is a schematic plan view of a packaging bag according to a modified example. [Figure 4] FIG. 4 is a schematic cross-sectional view taken along line IV-IV of FIG. 4. [Figure 5] FIG. 5 is a plan view of a laminate for a packaging bag obtained by unfolding a packaging bag according to a modified example.

Modes for Carrying Out the Invention

[0018] Hereinafter, with reference to the accompanying drawings, preferred embodiments of one aspect of the present invention will be described in detail. In the following description, the same reference numerals will be used for the same elements or elements having the same function, and redundant descriptions will be omitted.

[0019] <Laminate for Packaging Bag> The laminated packaging bag 1 will be described in detail with reference to Figure 1. Figure 1 is a schematic cross-sectional view of the laminated packaging bag. The laminated packaging bag 1 is a packaging paper used to form the packaging bag 2 shown in Figure 2, the packaging bag 2A shown in Figure 3, etc. The laminated packaging bag 1 can possess the required performance (for example, gas barrier properties, light shielding properties, water resistance, temperature and humidity resistance, mechanical strength, printability, printability, ease of decoration, etc.). Note that gas barrier properties refer to the ability to prevent or suppress the permeation of gases such as oxygen and water vapor (air permeability prevention). Water resistance is evaluated by the rate of strength reduction when the packaging bag 2, etc., gets wet. The laminated packaging bag 1 comprises a base material 11, a resin coating layer 12, a sealing layer 13, an ink 14, and an overcoat layer 15. The base material 11, the resin coating layer 12, the sealing layer 13, and the overcoat layer 15 overlap each other in the thickness direction of the base material 11 (hereinafter also simply referred to as the "thickness direction").

[0020] The base material 11 is a film-like member formed from the paper itself, and has main surfaces 11a and 11b. The main surfaces 11a and 11b are surfaces that intersect with respect to the thickness direction of the base material 11. When a packaging bag 2 is formed from the packaging bag laminate 1, one main surface 11a is located on the outer surface side of the packaging bag 2, and the other main surface 11b is located on the inner surface side of the packaging bag 2. The paper constituting the base material 11 is, for example, fine paper, special fine paper, art paper, Japanese paper, imitation paper, kraft paper, etc. The paper constituting the base material 11 is not particularly limited as long as it is not recycled paper, for example, fine paper, special fine paper, art paper, Japanese paper, imitation paper, kraft paper, etc. In this embodiment, the base material 11 is bleached kraft paper, but is not limited thereto. The base material 11 may be, for example, unbleached kraft paper. From the viewpoint of aesthetic appeal on the outer surface of the packaging bag 2, the base material 11 may be Unryu paper or mixed paper.

[0021] The mass of the base material 11 is, for example, 51% or more of the total mass of the base material 11, the resin coating layer 12, the sealing layer 13, the ink 14, and the overcoat layer 15. In this case, packaging bags can be manufactured from the laminated packaging bag 1 with good moldability.

[0022] The basis weight of base material 11 is 30 g / m².2 The above may be 170 g / m² 2 or less. From the viewpoint that the lower limit value of the basis weight of the base material 11 enables good bonding processing between a part and another part of the laminate 1 for packaging bags and suppresses the occurrence of visible damage or the like in the laminate 1 for packaging bags, for example, it may be 30 g / m² 2 or 40 g / m² 2 or 50 g / m² 2 or 60 g / m² 2 or the like. The upper limit value of the basis weight of the base material 11 is such that the laminate 1 for packaging bags does not become too hard and is easily formed into a bag shape, and when the seal layer 13 is heat-sealed, heat is favorably transferred to the seal layer 13 through the base material 11, so that from the viewpoint of exhibiting good sealing performance, it may be 170 g / m² 2 or 150 g / m² 2 or 100 g / m² 2 or less, or eighty g / m² 2 or less.

[0023] The resin coating layer 12 is a film-like member that covers the main surface 11a of the base material 11 and has main surfaces 12a and 12b. From the viewpoint of preventing air permeability of the laminate 1 for packaging bags, the resin coating layer 12 covers the entire surface of the main surface 11a of the base material 11. The main surfaces 12a and 12b are surfaces that intersect with the thickness direction of the base material 11. The main surface 12a is the exposed surface of the resin coating layer 12, and the main surface 12a corresponds to the surface of the resin coating layer 12 opposite to the base material 11. The main surface 12b is the surface that faces the base material 11 in the thickness direction. The main surface 12b may be in contact with the main surface 11a of the base material 11. The resin coating layer 12 may contain, for example, at least one selected from the group consisting of polyolefin resins, polyvinyl alcohol resins, and latex resins. Specific examples of polyolefin resins include polyethylene resin, polypropylene resin, and polybutylene resin. Examples of latex resins include styrene-butadiene resins, acrylonitrile-butadiene resins, and methyl methacrylate-butadiene resins. The resin coating layer 12 may contain at least one selected from the group consisting of polyolefin resins, polyvinyl alcohol resins, and latex resins in an amount of 5% to 90% by mass based on the total amount of the resin coating layer 12.

[0024] The mass of the resin coating layer 12 is, for example, 5% to 30% by mass of the total mass of the base material 11 and the resin coating layer 12, from the viewpoint of the mass of the laminated packaging bag 1, pattern reproducibility, and air permeability. Furthermore, if the mass of the resin coating layer 12 is within the above range, the occurrence of wrinkles during the manufacturing of the laminated packaging bag 1 can be suppressed. From the viewpoint of pattern reproducibility and air permeability, the mass of the resin coating layer 12 may be 10% or more by mass of the total mass, or 15% by mass. From the viewpoint of the mass of the laminated packaging bag 1, the mass of the resin coating layer 12 may be 25% or less by mass, or 20% or less by mass, of the total mass. The higher the pattern reproducibility, the closer the pattern printed on the laminated packaging bag 1 will be to the original pattern displayed on a display device, etc.

[0025] The Beck smoothness of the main surface 12a of the resin coating layer 12 may be between 350 seconds and 2000 seconds. The Beck smoothness is a value determined in accordance with JIS P8119:1998 "Paper and cardboard - Smoothness test method using a Beck smoothness tester".

[0026] The sealing layer 13 is used to bond a portion of the packaging bag laminate 1 to another portion and is located on the main surface 11b of the base material 11. Therefore, the sealing layer 13 is located on the opposite side of the resin coating layer 12, with the base material 11 in between, in the thickness direction. Also, when a packaging bag is formed from the packaging bag laminate 1, the sealing layer 13 is located inside the base material 11. In this embodiment, the sealing layer 13 covers a portion of the main surface 11b. Therefore, the main surface 11b is partially coated by the sealing layer 13, and a portion of the main surface 11b is exposed from the sealing layer 13. For example, the sealing layer 13 covers a portion of the main surface 11b such that it takes on a frame shape when viewed from the thickness direction. In this case, the sealing layer 13 may be provided along the edge of the main surface 11b. From the viewpoint of the mass of the packaging bag laminate 1, the sealing layer 13 covers, for example, 5% to 70% of the main surface 11b. Also, when a portion of the sealing layer 13 is joined to another portion, the occurrence of blocking at the joined portion can be suppressed. A portion of the sealing layer 13 and the other portion may be sealed, for example, by heat sealing, but this is not limited to that. The sealing layer 13 may also be sealed by, for example, cold sealing. A portion of the sealing layer 13 may form the inner surface of the packaging bag 2.

[0027] The seal layer 13 may be a heat-seal varnish or a cold-seal varnish. The seal layer 13 may contain, for example, polyolefin resin, polyacrylate resin, urethane resin, melamine resin, amino resin, epoxy resin, styrene resin, polyester resin, cellulose resin, vinyl chloride resin, polyvinyl alcohol resin, ethylene vinyl acetate copolymer, and mixtures thereof. More specifically, the seal layer 13 may contain polyethylene resin, polypropylene resin, polybutylene succinate (PBS), polylactic acid (PLA), polyhydroxyalkanoic acid (PHA), poly(butylene adipate / terephthalate) (PBAT), polycaprolactone (PCL), poly(hydroxybutyrate / hydroxyhexanoate) (PHBH). The seal layer 13 may also be an aqueous emulsion of acrylic, aqueous urethane resin, polyolefin resin, styrene-butadiene rubber (SBR), vinyl acetate, ethylene vinyl acetate copolymer, silicone, polybutene, etc. The sealing layer 13 may contain one type of resin from the above-mentioned resins, or it may contain multiple types of resins. The sealing layer 13 may also contain fillers, etc.

[0028] The seal layer 13 has a pigment composed of at least one of a phosphorescent pigment and a fluorescent pigment. That is, the seal layer 13 has a pigment consisting of a phosphorescent pigment, a fluorescent pigment, or a pigment consisting of a phosphorescent pigment and a fluorescent pigment. In this case, the seal layer 13 can emit light after being irradiated with light. The phosphorescent pigment is a substance that has phosphorescent properties, such as an aluminate. The fluorescent pigment is a substance that has fluorescent properties, such as a benzoxazolylthiophene-based fluorescent agent. At least one of the phosphorescent pigment and the fluorescent pigment may be colorless, transparent, or colorless and transparent. For example, the seal layer 13 contains the above pigment in an amount of 0.075% by mass or more relative to the mass of the seal layer 13. In this case, the position of the seal layer 13 located on the main surface 11b can be accurately detected by a light sensor or the like. The seal layer 13 may contain the above pigment in an amount of 0.1% by mass or more relative to the mass of the seal layer 13. In this case, workers can visually confirm the light emitted from the sealing layer 13, improving the detection accuracy of light sensors and the like. Furthermore, the sealing layer 13 contains, for example, the pigment in an amount of 5.5% by mass or less relative to the mass of the sealing layer 13. In this case, the precipitation of the pigment in the sealing layer 13 can be suppressed. From the viewpoint of the sealing performance of the sealing layer 13, the sealing layer 13 may contain, for example, the pigment in an amount of 5% by mass or less. If the pigment consists of a phosphorescent pigment and a fluorescent pigment, the content of the phosphorescent pigment and the content of the fluorescent pigment may each be 0.075% by mass or more, or 0.1% by mass or more, relative to the mass of the sealing layer 13.

[0029] The thickness of the sealing layer 13 may be 0.5 μm or more and 5 μm or less, 1 μm or more and 4 μm or less, or 2 μm or more and 3 μm or less, from the viewpoint of sealing performance.

[0030] The ink 14 corresponds to the printed portion of the laminated packaging bag 1 and is located on the main surface 12a of the resin coating layer 12. The ink 14 located on the resin coating layer 12 forms a design or pattern on the laminated packaging bag 1. In this embodiment, the ink 14 is, for example, a portion printed with water-based or oil-based ink and is attached to the main surface 12a of the resin coating layer 12. At least a portion of the ink contained in the ink 14 may penetrate into the main surface 12a. The ink 14 may be formed by mixing multiple inks or overlapping multiple inks. From the viewpoint of printability, cost, etc., the thickness of the ink 14 is, for example, 0.1 μm or more and 2 μm or less. In this embodiment, the thickness of the ink 14 is about 1 μm. The ink 14 may be attached to the entire main surface 12a of the resin coating layer 12, or to only a part of the main surface 12a. The packaging bag laminate 1 is equipped with ink 14, which improves the design of the packaging bag laminate and the packaging bag.

[0031] The overcoat layer 15 corresponds to the outermost surface of the packaging bag 2 and protects the ink 14 and the main surface 12a of the resin coating layer 12. The overcoat layer 15 covers the main surface 12a of the resin coating layer 12 and the ink 14. In this embodiment, the overcoat layer 15 completely overlaps the main surface 12a of the resin coating layer 12, but is not limited to this. The overcoat layer 15 includes, for example, paints such as varnish, UV-curing resins, thermoplastic resins, etc. From the viewpoint of design and moldability, the thickness of the overcoat layer 15 may be, for example, 0.1 μm or more and 5 μm or less. When paint is used, from the viewpoint of cost, coating performance, etc., the thickness of the overcoat layer 15 when paint is used may be 0.1 μm or more and 3 μm or less. When resins such as UV-curing resins and thermoplastic resins are used, the thickness of the overcoat layer 15 may be 1 μm or more and 5 μm or less. From the standpoint of cost, coating performance, etc., the thickness of the overcoat layer 15 when using the above resin may be 1 μm or more and 3 μm or less.

[0032] <Overview of the packaging bag> The packaging bag according to this embodiment will be described with reference to Figure 2. Figure 2 is a schematic plan view of the packaging bag.

[0033] The packaging bag 2 shown in Figure 2 is a sealed container for holding solids or the like, and is, for example, a paper container packaging bag. Paper container packaging bags are packaging bodies that are marked with an identification mark for paper container packaging in accordance with Japan's Law for Promotion of Effective Utilization of Resources. Therefore, the main component of the packaging bag 2 according to this embodiment is paper. In this embodiment, the mass of paper is 51% or more of the total mass of the packaging bag 2. The packaging bag 2 is composed of a laminate for packaging bags 1 (see Figure 1) and may contain contents. The packaging bag 2 is formed into a bag shape by sealing the ends of the laminate for packaging bags 1, for example, which is folded in half to sandwich the contents. The contents are not particularly limited and may include, for example, food and beverages, pharmaceuticals, cosmetics, chemicals, electronic equipment, tools, stationery, etc. The contents are not limited to solids, but may also be liquids or gases. The contents may be individually packaged.

[0034] The packaging bag 2 has a main body 4 in which the contents are contained, a sealing portion 5 located at the end of the main body 4, and a folded portion 6 in which the laminated packaging bag 1 is folded. The shape of the main body 4 is not particularly limited, and for example, it may be rectangular when viewed from a predetermined direction. At least a part of the outer surface of the main body 4 is printed (not shown). The main body 4 may contain, for example, a specific gas such as nitrogen in addition to the contents. The sealing portion 5 is the part in which a part of the laminated packaging bag 1 is bonded to another part. In the sealing portion 5, a part of the laminated packaging bag 1 and another part are in close contact with each other. The sealing portion 5 is formed, for example, by heating and compressing a part of the laminated packaging bag 1 and another part (i.e., heat sealing), but is not limited to this. For example, the sealing portion 5 may be formed by cold sealing or the like. In this embodiment, when viewed from a predetermined direction, the folded portion 6 constitutes one side of the main body 4, and the sealing portion 5 constitutes the remaining three sides of the main body 4. The ends of the bent portion 6 and the sealing portion 5 overlap.

[0035] The following describes an example of a method for manufacturing a packaging bag 2 using a laminate 1 for packaging bags. First, a sheet-like paper base material 11 is prepared (first step). In the first step, the base material 11 is formed, for example, under known papermaking conditions and papermaking methods. When viewed from the thickness direction of the base material 11, the base material 11 has a substantially rectangular shape. As the main material of the base material 11, only kraft pulp may be used, only recycled paper pulp may be used, or a mixture of kraft pulp and recycled paper pulp may be used. The type of kraft pulp and the type of recycled paper pulp are not particularly limited. When forming the base material 11, sizing agents such as aluminum sulfate and rosin, paper strength enhancers such as polyamide and starch, filtration yield improvers, water-resistant agents such as polyamide, polyamine, and epichlorohydrin, dyes, etc., may be used.

[0036] Next, a resin coating layer 12 is formed to cover the main surface 11a of the substrate 11 (second step). In the second step, the resin coating layer 12 is formed by known methods such as gravure printing, offset printing, flexographic printing, digital printing, or cast coating.

[0037] Next, ink 14 is formed on the main surface 12a of the resin coating layer 12 (third step). At this time, in addition to the desired pattern, marks (ink marks) are printed. The ink marks are used, for example, as registration marks or trim marks. In the third step, ink 14 is formed by printing ink on the main surface 12a using a known printing method. Known printing methods include, for example, gravure printing, offset printing, flexographic printing, and digital printing.

[0038] Next, a sealing layer 13 is formed to cover a portion of the main surface 11b of the substrate 11 (fourth step). In the fourth step, first, a solution (coating liquid) in which a resin and pigment are dissolved, such as heat-seal varnish, is coated onto a portion of the main surface 11b. Subsequently, the sealing layer 13 is formed by removing the solvent from the coating liquid. The removal of the solvent is carried out, for example, by leaving the substrate 11 to which the coating liquid has been applied in an environment with a temperature higher than room temperature. For example, the sealing layer 13 is formed on a portion of the main surface 11b by using the ink marks on the resin coating layer 12 and the pigment contained in the sealing layer 13.

[0039] Next, an overcoat layer 15 is formed to cover the main surface 12a of the resin coating layer 12 and the ink 14 (fifth step). In the fifth step, the overcoat layer 15 is formed over the entire main surface 12a of the resin coating layer 12 by a well-known method such as offset printing, gravure printing, roll coating, air knife method, or doctor blade method. If the overcoat layer 15 contains a thermoplastic resin, the overcoat layer 15 may be formed by, for example, extruder processing (extrusion molding).

[0040] Next, the base material 11 is bent and a portion of the seal layer 13 is bonded to another portion to form a bag-shaped packaging bag 2 (sixth step). In the sixth step, the base material 11 is first folded in half. At this time, the base material 11 is folded so that the seal layer 13 is located on the inside and the edges of one folded base material 11 are aligned to the other. The folded base material 11 has a roughly rectangular shape. The three edges of the base material 11, excluding the folded portion, are open ends. Subsequently, the contents are supplied between the folded base material 11, and then the three edges and their surroundings are pressurized under heating conditions. At this time, a portion of the seal layer 13 that is in contact with the edges and their surroundings is bonded to the other portion. This forms a packaging bag 2, which is a sealed container for holding the contents.

[0041] In the above embodiment, the packaging bag is manufactured by sequentially carrying out steps 1 through 6, but it is not limited to this. The order of steps 1 through 6 may be changed as appropriate. For example, step 4 may be carried out before step 2.

[0042] The packaging bag 2 manufactured by the manufacturing method according to the embodiment described above is formed using a laminated packaging bag 1 having a paper base material 11, a resin coating layer 12, a sealing layer 13, ink 14, and an overcoat layer 15. Such a packaging bag 2 has a sheet-like resin coating layer 12 that covers the main surface 11a of the paper base material 11, and the ink 14 is located on the resin coating layer 12. Therefore, compared to the case where ink is applied directly to the paper base material, the reproducibility of the design can be improved. In addition, the mass of the resin coating layer 12 is 5% by mass or more and 30% by mass or less of the total mass of the base material 11 and the resin coating layer 12. This makes it possible to improve the air permeability of the laminated packaging bag 1 while suppressing the mass increase of the laminated packaging bag 1. In addition, the sealing layer 13 covers a part of the main surface 11b of the base material 11 and contains a pigment composed of at least one of a phosphorescent pigment and a fluorescent pigment in an amount of 0.075% by mass or more and 5.5% by mass or less of the mass of the sealing layer 13. This allows for accurate detection of the position of the sealing layer 13 provided on a part of the base material 11. For this reason, by using, for example, an ink mark printed on the resin coating layer 12 and the sealing layer 13, it is easy to determine whether there is a misalignment between the position of the design printed on the resin coating layer 12 and the position of the sealing layer 13. In other words, it is easy to determine whether there is a misalignment between the sealing layer 13 and the ink 14. Therefore, according to this embodiment, it is possible to manufacture the packaging bag 2 (and the laminate for the packaging bag 1) with a high yield while suppressing an increase in the mass of the packaging bag 2 (and the laminate for the packaging bag 1).

[0043] In addition, in this embodiment, since the mass of the resin coating layer 12 is 5% by mass or more and 30% by mass or less of the total mass, the occurrence of wrinkles during the manufacturing of the laminated packaging bag 1 can be suppressed. Furthermore, since the seal layer 13 contains pigment in an amount of 0.075% by mass or more and 5.5% by mass or less of the mass of the seal layer 13, it is easier to align a part of the seal layer 13 with other parts when manufacturing the packaging bag 2.

[0044] In this embodiment, the basis weight of the base material 11 is 30 g / m². 2 More than 170g / m 2 The following is also acceptable. In this case, damage to the base material 11 is less likely to occur when forming the packaging bag 2 from the packaging bag laminate 1. Also, since the packaging bag laminate 1 does not become too hard, the packaging bag 2 can be formed well from the packaging bag laminate 1.

[0045] In this embodiment, the resin coating layer 12 contains at least one selected from the group consisting of polyolefin resin, polyvinyl alcohol resin, and latex resin. Therefore, the main surface 11a of the substrate 11 is less likely to be exposed from the resin coating layer 12 on which the ink 14 is printed. Consequently, the whitening phenomenon of the packaging bag laminate 1 caused by the exposed main surface 11a is less likely to occur.

[0046] In this embodiment, the mass of the resin coating layer 12 may be 10% by mass or more and 20% by mass or less of the total mass of the base material 11 and the resin coating layer 12. In this case, the air permeability can be further improved.

[0047] In this embodiment, the Beck smoothness of the main surface 12a of the resin coating layer 12 may be 350 seconds or more and 2000 seconds or less. In this case, the pattern reproducibility can be further improved.

[0048] In this embodiment, the seal layer 13 may contain the pigment in an amount of 0.1% to 5% by mass relative to the mass of the seal layer 13. In this case, the position of the seal layer 13 can be detected with greater accuracy while maintaining the sealing properties of the seal layer 13.

[0049] In this embodiment, the sealing layer 13 may cover 5% to 70% of the main surface 11b of the base material 11. In this case, the amount of resin used to form the sealing layer 13 can be reduced, thereby suppressing an increase in the mass of the packaging bag laminate 1 and preventing blocking.

[0050] In this embodiment, an overcoat layer 15 is provided to cover the ink 14, and the thickness of the overcoat layer 15 is 5 μm or less. Since the laminated packaging bag 1 is provided with a resin coating layer 12, even if the thickness of the overcoat layer 15 is 5 μm or less, the overall air permeability of the laminated packaging bag 1 is good. In addition, the amount of resin or the like used to form the overcoat layer 15 can be reduced.

[0051] The following describes modified versions of the above embodiment with reference to Figures 3 to 5. In the following modifications, the explanation of parts that overlap with the above embodiment will be omitted. Therefore, the following will mainly describe the parts that differ from the above embodiment. Figure 3 is a schematic plan view of the packaging bag according to the modified version. Figure 4 is a schematic cross-sectional view along line IV-IV in Figure 3. Figure 5 is a plan view of the laminated packaging bag obtained by unfolding the packaging bag according to the modified version.

[0052] The modified packaging bag 2A is a pillow packaging bag composed of a laminate for packaging bags 1, similar to the embodiment described above. The pillow packaging bag can be formed, for example, by using a known pillow packaging filling machine. In this modified example, the packaging bag 2A, which is a pillow packaging bag, is formed by bending the base material 11 using the above packaging filling machine so that the seal layer 13 is located on the inside, and then bonding a part of the seal layer 13 to another part. The base material 11 of the packaging bag 2A has a cylindrical body portion 21 and a flange portion 22. Hereinafter, the axial direction of the body portion 21 will be referred to as direction X as shown in Figure 3, and the direction perpendicular to direction X will be referred to as direction Y. Direction Y corresponds to the thickness direction of the base material 11 and the direction perpendicular to direction X when the base material 11 is unfolded, as shown in Figure 5.

[0053] The main body portion 21 is the part that contains the contents of the packaging bag 2A. The main body portion 21 is formed by rolling the laminated packaging bag 1 along direction Y. Both ends 23 of the main body portion 21 in direction X are sealed by the seal layer 13. From the viewpoint of content storage, the dimensions of the main body portion 21 along direction X are, for example, 80% or more of the dimensions of the base material 11 along direction X. From the viewpoint of sealing of both ends 23, the dimensions of the main body portion 21 along direction X are, for example, 90% or less of the dimensions of the base material 11 along direction X. Notches may be provided in the main body portion 21 to allow easy tearing of the packaging bag 2A. In this case, notches may be provided on only one of the ends 23.

[0054] The flange portion 22 is a part provided when the packaging bag 2A is formed, extending along direction X and protruding from the main body portion 21. The flange portion 22 extends from one end to the other end of the packaging bag 2A in direction X. The flange portion 22 corresponds to the part where a pair of ends 11c and 11d of the base material 11 in direction Y are bonded together by the seal layer 13 when the base material 11 is unfolded (see Figure 5). When the base material 11 is unfolded, the dimensions of the flange portion 22 along direction Y are, for example, 2% to 5% of the dimensions of the base material 11 along direction Y. In this case, the flange portion 22 is bonded well while ensuring the volume of the packaging bag 2A. The bonding of the pair of ends 11c and 11d via the seal layer 13 is performed simultaneously with the sealing of both ends 23 of the main body portion 21 via the seal layer 13.

[0055] Typically, in pillow packaging bags, poor adhesion is prone to occur at the boundary between the pair of ends constituting the flange portion and the main body portion. In contrast, in this modified example, as in the above embodiment, the alignment of the seal layers 13 is made easier. As a result, the boundary between the pair of ends 11c, 11d constituting the flange portion 22 of the packaging bag 2A and the main body portion 21 is also well sealed by the seal layer 13. In addition, in this modified example, as in the above embodiment, it is possible to improve the pattern reproducibility and air permeability, and it is possible to suppress the mass increase that accompanies such improvements. Furthermore, since the packaging bag 2A is equipped with a seal layer having a pigment content of 0.1% to 5% by mass relative to the mass of the seal layer, it is easy to align the seal layers when manufacturing the packaging bag, and as a result, it is manufactured with a good yield.

[0056] In Figure 4, only the base material 11, resin coating layer 12, sealing layer 13, and ink 14 are laminated, but this is not limited to this. For example, an overcoat layer or the like may be laminated.

[0057] Laminates for packaging bags and packaging bags according to one aspect of the present invention are not limited to the above embodiments and modifications. For example, in the above embodiments, the laminate for packaging bags comprises a base material, a resin coating layer, a seal layer, an ink layer, and an overcoat layer, but is not limited thereto. For example, the laminate for packaging bags may comprise at least one of a barrier coating layer, a water-resistant coating layer, and an oil-resistant coating layer. At least one of the barrier coating layer, water-resistant coating layer, and oil-resistant coating layer may be located, for example, between the base material and the seal layer, between the base material and the resin coating layer, or between the resin coating layer and the ink. The barrier coating layer, water-resistant coating layer, and oil-resistant coating layer can be formed, for example, by existing methods and materials. Alternatively, the laminate for packaging bags may comprise a reinforcing layer to improve physical strength. The reinforcing layer may be located, for example, between the base material and the seal layer, between the base material and the resin coating layer, or between the base material and the ink. The reinforcing layer may be, for example, an unstretched film or a stretched film. In this case, the reinforcing layer includes, for example, a thermoplastic resin such as polyamide, polypropylene, or polyester. Alternatively, the above-mentioned barrier layer, reinforcing layer, etc., may be formed on the seal layer. In this case, these layers only need to be of a thickness that can be broken when the seal layer is bonded. The breakable thickness may be, for example, 5 μm or less, 3 μm or less, or 1 μm or less.

[0058] The laminate for packaging bags may include a vapor-deposited layer. The vapor-deposited layer may have at least one of the functions of a barrier coat layer, a water-resistant coat layer, an oil-resistant coat layer, and a reinforcing layer. Examples of vapor-deposited layers include silica vapor-deposited layers, alumina vapor-deposited layers, and aluminum vapor-deposited layers. The vapor-deposited layer is formed, for example, by physical vapor deposition. The vapor-deposited layer is formed on a substrate, but is not limited to this.

[0059] As described above, the packaging bag may be manufactured by folding the laminate for packaging bags in half, or by bending it multiple times. Alternatively, the packaging bag may be manufactured without folding the laminate for packaging bags. In this case, for example, the packaging bag is manufactured by sealing the ends of two laminates for packaging bags that are overlapped. Furthermore, the packaging bag does not necessarily have to be airtight. For example, at least a part of the packaging bag may be open. Or, a part of the packaging bag may have an openable and closable portion. [Examples]

[0060] The present invention will be described in more detail by the following examples, but the present invention is not limited to these examples.

[0061] (Example 1) <Laminated body for packaging bags> First, the sheet-like paper-based substrate has a basis weight of 65 g / m². 2 Bleached kraft paper was prepared. In this embodiment, a rectangular paper substrate was used. Next, a resin mainly composed of polyethylene resin, polypropylene resin, polyvinyl alcohol resin, or latex-based resin was applied to one side of the substrate. Next, the applied resin was dried to obtain a resin coating layer that covered the entire surface. Next, a source drawing with the desired pattern was prepared, and colored ink was printed on the exposed surface of the resin coating layer using gravure printing so that the same pattern as the source drawing appeared on the exposed surface. In addition to the pattern, an ink mark was also printed. The colored ink was dried. The colored ink was printed so that the thickness of the colored ink after drying was approximately 1 μm.

[0062] Next, a pigment consisting of at least one of a fluorescent whitening agent and a phosphorescent agent was mixed into HS varnish (Dainichi Seika Kogyo Co., Ltd., "Seikadain 1900W") at a concentration of 0.1% by mass relative to the total amount of HS varnish to obtain a pigment-mixed HS varnish. The obtained pigment-mixed HS varnish was coated onto the other side of the substrate. Light was shone onto the pigment-mixed HS varnish to detect the position of light emission, and the coating position of the pigment-mixed HS varnish was adjusted to match the position of the ink marks (i.e., registration adjustment was performed). The pigment-mixed HS varnish was coated along the edge of the substrate to form a frame shape. The width of the coated pigment-mixed HS varnish was 13 mm. At this time, the HS varnish was coated so that its thickness after drying was 3 μm. Then, the pigment-mixed HS varnish was dried at 90°C for 20 seconds to form a 3 μm thick sealing layer on one side of the substrate.

[0063] After the color ink had dried, OPP varnish was printed onto it using gravure printing. The OPP varnish was printed so as to cover the color ink and the resin coating layer. The printing was carried out so that the thickness of the dried OPP varnish was approximately 1 μm. In this way, a laminate for a packaging bag was formed having OPP varnish, ink, resin coating layer, substrate, and sealing layer.

[0064] <Packaging bag> First, the laminated material for the packaging bag was bent so that the sealing layer was on the inside, and both ends were overlapped by approximately 1 cm and heat-sealed. This resulted in a cylindrical body with a back seal. Next, heat sealing was performed to divide the cylindrical body at predetermined intervals along its axial direction. This resulted in a pillow packaging bag with a back seal and end seals and a top seal with a width of approximately 1 cm. The above operations were performed using a vertical pillow bag making machine ("INSPIRA" manufactured by Ishida Co., Ltd.). The heat sealing was performed under the conditions of 180°C, 0.2 MPa, and 0.5 sec.

[0065] <Smoothness> The smoothness of the exposed surface of the resin coating layer before printing with colored ink was determined in accordance with JIS P8119:1998 "Paper and cardboard - Method for testing smoothness using a Beck smoothness tester". The measurements were performed using a Beck smoothness tester HK type "0518-P" manufactured by Kumagai Riki Kogyo Co., Ltd.

[0066] <Image Reproducibility> First, 30 randomly selected panelists were prepared. Next, each panelist compared the pattern printed on the laminated packaging material with the original image displayed on a display device such as a display unit. Then, each panelist judged whether the shape, color, texture, etc., of the pattern printed on the laminated packaging material reproduced the original image. If 20 or more out of 30 panelists judged that the original image was reproduced, it was marked as "○" (correct), and if 19 or fewer out of 30 judged that the original image was reproduced, it was marked as "×" (incorrect).

[0067] <Air permeability prevention> Pillow packaging bags were manufactured using laminated materials for packaging bags. A "○" was given if there was no air leakage, and a "×" was given if there was air leakage.

[0068] <Is it possible to adjust the registration of the front and back sides?> The ability to align the printed pattern with the pigment-mixed HS varnish was evaluated using a printing press. A substrate with an ink mark printed on one side and a pigment-mixed HS varnish coated on the other side was moved at a Line Speed ​​(LS) of 150 m / min, and light was shone onto the pigment-mixed HS varnish on the substrate using a UV strobe with a chip LED light source. The adjustable range of the UV strobe was 30 to 10,000 rpm, and the emission time was 10 to 100 μs. The chip LED light source emitted 365 nm UV light and visible light, and the UV irradiance at a distance of 10 cm from the light source was approximately 17 mW / cm. Next, the experimenter visually observed whether there were any areas that emitted light on the substrate. The UV strobe irradiation and observation of emission were performed in a darkroom. If an area that emitted light on the substrate was visible after strobe irradiation, it was marked as "○"; if no area that emitted light was visible, it was marked as "×".

[0069] <Blocking> Using the laminated material for packaging bags described above, a 150mm x 150mm pillow packaging bag was created. At this time, the width of the sealed portion (seal width) was adjusted to 10mm before creating the pillow packaging bag. Then, a load of 0.4kN / cm was applied. 2 Under room temperature conditions, the entire pillow packaging bag was pressurized for three days. After that, when opening the pillow packaging bag by peeling off the adhesive parts between the seal layers, if damage occurred to the pillow packaging bag before the adhesive parts began to peel off, it was considered that blocking occurred. If the seal layers did not adhere to each other, or if the adhesive parts could be peeled off without damaging the pillow packaging bag, it was considered that blocking did not occur.

[0070] (Examples 2-6, Comparative Examples 1-8, and Reference Examples 1,2) Laminated packaging bags and pillow packaging bags were prepared in the same manner as in Example 1, except for the composition shown in Tables 1 and 2, the mass of the resin coating layer, the pigment content in the HS varnish, and the coating method of the seal layer. The pattern reproducibility and air permeability were then evaluated. For transparent vapor-deposited PET12, "GL-RD" (thickness 12 μm) manufactured by Toppan Printing Co., Ltd. was used. For PE15, PE30, and PE50, "SE620N" manufactured by Tamapoly Co., Ltd. was used. For NY15, "ONBC" manufactured by Unitika Ltd. was used. The results are shown in Table 2.

[0071] [Table 1]

[0072] [Table 2] [Explanation of symbols]

[0073] 1...Laminate for packaging bags, 2, 2A...Packaging bags, 4...Main body, 5...Sealing part, 6...Folding part, 11...Base material, 11a...Main surface (one side), 11b...Main surface (other side), 11c, 11d...Ends, 12...Resin coating layer, 12a, 12b...Main surface, 13...Sealing layer, 14...Ink, 15...Overcoat layer, 21...Main body, 22...Flange part, 23...Both ends.

Claims

1. A sheet-like material made of paper, A resin coating layer covering one side of the substrate, A sealing layer covering a portion of the other surface of the aforementioned substrate, An ink containing a design and an ink mark located on the surface of the resin coating layer opposite to the substrate, Equipped with, The mass of the resin coating layer is 5% by mass or more and 30% by mass or less of the total mass of the substrate and the resin coating layer. The sealing layer has a pigment composed of at least one of a phosphorescent pigment and a fluorescent pigment. A laminate for packaging bags, wherein the pigment content is 0.075% by mass or more and 5.5% by mass or less relative to the mass of the sealing layer.

2. The basis weight of the aforementioned substrate is 30 g / m². ２ More than 170g / m ２ The laminate for packaging bags according to claim 1, which is as follows:

3. The laminate for packaging bags according to claim 1 or 2, wherein the resin coating layer contains at least one selected from the group consisting of polyolefin resins, polyvinyl alcohol resins, and latex resins.

4. The laminate for packaging bags according to any one of claims 1 to 3, wherein the mass of the resin coating layer is 10% by mass or more and 20% by mass or less of the total mass of the base material and the resin coating layer.

5. The laminate for packaging bags according to any one of claims 1 to 4, wherein the Beck smoothness of the resin coating layer on the side opposite to the substrate is 350 seconds or more and 2000 seconds or less.

6. The laminate for packaging bags according to any one of claims 1 to 5, wherein the sealing layer contains the pigment in an amount of 0.1% by mass or more and 5% by mass or less relative to the mass of the sealing layer.

7. The laminate for packaging bags according to any one of claims 1 to 6, wherein the sealing layer covers 5% to 70% of the other surface of the base material.

8. The above ink is further covered by an overcoat layer, The laminate for packaging bags according to any one of claims 1 to 7, wherein the thickness of the overcoat layer is 5 μm or less.

9. A laminate for packaging bags according to any one of claims 1 to 8, A packaging bag in which a portion of the sealing layer that overlaps in the thickness direction of the substrate and another portion of the sealing layer that overlaps in the thickness direction of the substrate are sealed.

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