Package and manufacturing method thereof

Abstract

To provide a package that is excellent in pressure resistance while reducing environmental load.SOLUTION: A package includes: a packaging bag that has a sealed portion in which at least parts of outer edges of two laminated parts are bonded together, and a storage portion between the two laminated parts; and storage content sealed in the storage portion. At least one of the two laminated parts includes a laminate which has a base film, a primer layer, an adhesive layer, and a sealant layer in this sequence and in which an electrostatic ink layer is interposed between the primer layer and the adhesive layer. The adhesive layer includes a solventless adhesive composition that contains a polyisocyanate component including a derivative of hexamethylene diisocyanate and a polyol component, a cured product thereof, or a mixture thereof. When a load of 70 kg is applied to the storage portion for 3 minutes, the floating length L generated in the sealed portion is 0.5 mm or less with the boundary line between the sealed portion and the storage portion before applying the load as a reference.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to packaging and methods for making same. [Background technology]

[0002] Packaging bags for containing and sealingly storing beverages, foodstuffs, and the like are known. Packages using thin films or sheets are used as packaging bags. Various information such as product, brand, manufacturer, and the like is printed on such packaging bags. As a means for such printing, a digital printer using an electrostatic ink composition is known.

[0003] For example, Patent Document 1 proposes applying a primer resin to a first flexible substrate such as a PET film to obtain a coating surface, performing electrostatic printing on the coating surface using a digital printer (Indigo 20000 label and packaging digital printer manufactured by HP), and applying a crosslinking composition. It is known that the adhesive strength of a laminate including an electrostatic ink layer formed by such digital printing is reduced. Therefore, Patent Document 2 proposes using a cured product of a polyol, a polyisocyanate, and an epoxy compound as an adhesive layer as a laminate capable of maintaining a sufficiently high adhesive strength between layers even under high-temperature hot water conditions such as retort treatment.

[0004] On the other hand, from the viewpoint of reducing the environmental load, adhesives that do not contain organic solvents are being developed. For example, Patent Document 3 proposes a two-component curing solventless adhesive containing a polyisocyanate component and a polyol component, and a composite film for packaging foods, beverages, medicines, quasi-drugs, etc. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2018-530478 [Patent Document 2] International Publication No. 2021 / 024981 [Patent Document 3] JP 2011-162656 A Summary of the Invention [Problem to be solved by the invention]

[0006] A package including a packaged article in a packaging bag having a laminate may be subjected to high pressure due to impact during transportation, etc. The electrostatic ink layer used in the laminate has a weak cohesive force and a low adhesive strength, so when a printed surface by electrostatic printing is adhered using a conventional solvent-free adhesive composition, the laminate may peel off at the sealed part of the package and cause lifting when high pressure is applied to the package. When lifting occurs in the sealed part, the seal strength of the sealed part is reduced, making the package more likely to break. Therefore, the present disclosure provides a package including a laminate having an electrostatic ink layer, which has excellent pressure resistance while reducing environmental load, and a method for manufacturing the same. [Means for solving the problem]

[0007] One aspect of the present disclosure provides a package comprising: a packaging bag having a sealed portion in which at least a portion of the outer edges of a first laminate portion and a second laminate portion are bonded together, and a storage portion formed between the first laminate portion and the second laminate portion; and a content sealed in the storage portion, wherein at least one of the first laminate portion and the second laminate portion comprises a laminate having a base film, a primer layer, an adhesive layer, and a sealant layer, in this order, and an electrostatic ink layer is interposed at least on one side between the primer layer and the adhesive layer, and the adhesive layer comprises a solvent-free adhesive composition containing a polyisocyanate component including a derivative of hexamethylene diisocyanate and a polyol component, a cured product thereof, or a mixture thereof, and wherein when a load of 70 kg is applied to the storage portion for 3 minutes, a length L of lift generated in the sealed portion is 0.5 mm or less, based on a boundary line between the sealed portion and the storage portion before the load is applied.

[0008] When a load of 70 kg is applied to the storage section for 3 minutes, the length L of the lift that occurs in the sealed section is 0.5 mm or less, based on the boundary between the sealed section and the storage section before the load is applied. Since the adhesive layer of such a package contains a specific solventless adhesive composition, its cured product, or a mixture of these, it has excellent pressure resistance while reducing the environmental load, and can suppress breakage of the bag due to impact during transportation. In addition, since digital printing (electrostatic printing) can be used, the degree of freedom in designing the package can be sufficiently increased.

[0009] One aspect of the present disclosure provides a method for producing a package, the method including the steps of bonding at least a portion of the outer edges of a first laminate portion and a second laminate portion together to form a seal portion, and sealing a content in a storage portion between the first laminate portion and the second laminate portion, wherein at least one of the first laminate portion and the second laminate portion includes a laminate having a base film, a primer layer, an adhesive layer, and a sealant layer, in this order, and an electrostatic ink layer is interposed at least on one side between the primer layer and the adhesive layer, the adhesive layer includes a solventless adhesive composition including a polyisocyanate component including a derivative of hexamethylene diisocyanate and a polyol component, a cured product thereof, or a mixture thereof, and when a load of 70 kg is applied to the storage portion for 3 minutes, the length L of the lift generated in the seal portion is 0.5 mm or less, based on the boundary line between the seal portion and the storage portion before the load is applied.

[0010] In the package obtained by the above manufacturing method, when a load of 70 kg is applied to the storage section for 3 minutes, the length L of the lift generated in the sealed section is 0.5 mm or less, based on the boundary between the sealed section and the storage section before the load is applied. Since the adhesive layer of such a package contains a specific solventless adhesive composition, its cured product, or a mixture of these, it has excellent pressure resistance while reducing the environmental load, and can suppress breakage of the bag due to impact during transportation. In addition, since digital printing (electrostatic printing) can be used, the degree of freedom in designing the package can be sufficiently increased. Effect of the Invention

[0011] A packaging body including a laminate having an electrostatic ink layer can be provided that has excellent pressure resistance while reducing the environmental impact, and a manufacturing method thereof. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a plan view showing an example of a packaging body. [Diagram 2] 2 is a cross-sectional view of the package shown in FIG. 1 taken along line II-II. [Diagram 3] FIG. [Figure 4] 1 is a cross-sectional view showing an example of a package in which a seal portion has become bulged. [Diagram 5] FIG. 11 is a plan view showing an example of a package in which a seal portion where lifting has occurred is enlarged. [Figure 6] FIG. 2 is a cross-sectional view showing an example of a laminate. [Figure 7] FIG. 4 is a cross-sectional view showing another example of a laminate. [Figure 8] FIG. 1 is a perspective view showing an example of a packaging bag. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings as needed. However, the following embodiment is an example for explaining the present disclosure, and is not intended to limit the present disclosure to the following content. In the description, the same reference numerals are used for the same elements or elements having the same functions, and redundant description is omitted as the case may be. In addition, the positional relationship such as up, down, left, right, etc. is based on the orientation of the reference numerals shown in the drawings, unless otherwise specified. Furthermore, the dimensional ratio of each element is not limited to the ratio shown in the drawings.

[0014] Unless otherwise specified, the materials exemplified in this disclosure can be used alone or in combination of two or more. When there are multiple substances corresponding to each component in the composition, the content of each component in the composition means the total amount of the multiple substances present in the composition, unless otherwise specified. In this disclosure, a numerical range indicated using "~" indicates a range including the respective numerical values ​​described before and after "~" as the minimum and maximum values. In this disclosure, the upper limit and lower limit values ​​indicated individually can be arbitrarily combined.

[0015] [Packaging] Fig. 1 is a plan view showing an example of a package according to the present disclosure, and Fig. 2 is a cross-sectional view of the package taken along line II-II in Fig. 1. Package 200 includes a packaging bag 100 having a first laminated section 301, a sealed section 101 formed by bonding at least a portion of the outer edges of a second laminated section 302 together, and a storage section 102 formed between first laminated section 301 and second laminated section 302. First laminated section 301 and second laminated section 302 may have the same laminated structure or may have different laminated structures.

[0016] 2, at least one of the first laminated part 301 and the second laminated part 302 includes a laminate having, in this order, a base film 10, a primer layer 40, an electrostatic ink layer 50, an adhesive layer 30, and a sealant layer 20. Details of the laminate will be described later.

[0017] The sealed portion 101 may be formed by heat-sealing and bonding the sealant layers 20 of the first laminated portion 301 and the second laminated portion 302 together. Alternatively, the sealant layer 20 of either the first laminated portion 301 or the second laminated portion 302 may be heat-sealed to a layer other than the sealant layer. An impulse sealer or the like may be used for heat sealing, and the heat sealing conditions may be, for example, 160° C., 0.2 MPa, and 0.5 seconds.

[0018] The size of the packaging bag 100 may be within a range that allows the formation of the sealed portion 101 and the containing portion 102. Furthermore, the shape of the packaging bag 100 is not particularly limited. The shape of the outer edge of the packaging bag 100 is not limited to a straight line, and a part of the outer edge may be curved. The width of the sealed portion 101 may be 5 to 30 mm, 10 to 25 mm, or 12 to 20 mm. By setting the width of the sealed portion 101 within this range, the volume of the containing portion 102 can be sufficiently increased while further improving the seal strength.

[0019] The volume of the storage section 102 may be 1 to 1000 mL, 5 to 500 mL, 10 to 100 mL, or 15 to 50 mL, from the viewpoint of further improving the seal strength while ensuring a sufficient volume for placing the contents inside.

[0020] The seal strength of the sealed portion 101 may be 15.0N / 15mm width or more, 20.0N / 15mm width or more, or 25.0N / 15mm width or more. When the seal strength of the sealed portion 101 is in this range, a package 200 having sufficiently high pressure resistance can be obtained. The seal strength can be measured in accordance with JIS K 7127:1999 "Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets". The seal strength may be 40.0N / 15mm width or less. The range of the seal strength may be, for example, 15.0 to 40.0N / 15mm width, 20.0 to 40.0N / 15mm width, or 25.0 to 40.0N / 15mm width.

[0021] The packaging bag 100 may be provided with an opening means 120 for facilitating opening. The opening means has a pair of easy-to-open processed parts 124 consisting of V-shaped notches formed in the sealed part 101 at the side end, and a half-cut line 121 that serves as a slitting path between the pair of easy-to-open processed parts 124. The half-cut line 121 can be formed using a laser. The easy-to-open processed parts 124 are not limited to V-shaped notches, and may be U-shaped or I-shaped notches, or may be a group of scars.

[0022] The package 200 includes a packaging bag 100 and an item contained in a storage section 102 of the packaging bag 100. The item is sealed in the storage section 102. The item may be a liquid, and may be a liquid, an emulsion, a particle dispersion, a gel, or a mixture thereof. Examples of the item include food, beverages, medicines, hair care products, and cosmetics.

[0023] When a pressure resistance test of the packaging body 200 is conducted in which a load of 70 kg is applied to the storage portion 102 for three minutes, the length of lifting that occurs in the sealed portion 101 is 0.5 mm or less, based on the boundary line between the sealed portion 101 and the storage portion 102 before the load is applied. The pressure resistance test can be conducted in accordance with "10. Compression resistance test" of JIS Z 0238:1998 "Test methods for heat-sealed flexible packaging and semi-rigid containers."

[0024] The procedure for the pressure resistance test in the present disclosure will be described below with reference to Fig. 3. First, the package 200 is placed on the sample support stage 400. Then, the pressure plate 402 and the weight 405 are placed on the storage section 102 so that the load on the storage section 102 is 70 kg, and the storage section 102 is left to stand for three minutes, and the length of the lift that occurs on the seal section 101 after three minutes is observed. The load is applied in the direction X perpendicular to the sample support stage 400 (vertical direction). By observing the length of the lift that occurs by the above procedure, the pressure resistance of the package 200 when a load of 70 kg is applied for three minutes can be evaluated.

[0025] The floating in the present disclosure may occur, for example, when the pressure resistance test is performed, due to interfacial peeling of the adhesive layer 30 from the boundary between the sealed portion 101 and the storage portion 102 toward the sealed portion 101 side. It may also occur due to cohesive peeling of the electrostatic ink layer 50. When the floating occurs, it can be visually confirmed that the base film 10 is lifted at the sealed portion 101. FIG. 4 is a cross-sectional view showing an example of a package in which the floating has occurred. By observing the cross-section as in FIG. 4, it can be confirmed that the floating V occurs not due to peeling of the heat-sealed sealant layer 20, but due to peeling of the adhesive portion of the adhesive layer 30. The peeling may be interfacial peeling on either side of the adhesive layer 30, or peeling due to cohesive failure of the adhesive layer 30. When the floating V occurs, the pressure resistance of the sealed portion 101 decreases. Therefore, a package in which such floating occurs is easily broken by impact due to pressure or the like. Therefore, it is preferable that the floating does not occur as much as possible.

[0026] In the package 200 after the pressure resistance test, the length of the lifting caused in the sealed portion 101 by the above-mentioned pressure resistance test can be obtained by measuring the maximum value of the length of the lifting along a direction perpendicular to the boundary line between the sealed portion 101 and the storage portion 102 before the load is applied, using a ruler or the like. In order to show an example of a method for measuring the length of the lifting, FIG. 5 shows a plan view of an example of the package 200 in which the sealed portion 101 with the lifting V has been enlarged. The lifting V may occur from the boundary line K between the sealed portion 101 and the storage portion 102 toward the sealed portion 101. As shown in FIG. 5, the length L of the lifting is the maximum value of the length of the lifting along a direction P perpendicular to the boundary line K from the boundary line K toward the sealed portion 101, and this length can be obtained by measuring with a ruler or the like. When the boundary line is a curve, the length of the lifting along a direction perpendicular to the tangent line of the boundary line may be measured. The package 200 having the length L of the lift of 0.5 mm or less is preferable because it has sufficiently high pressure resistance and is less likely to break. The length L of the float may be 0.3 mm or less, or may be 0.1 mm or less. The package 200 having the float length within this range has sufficiently excellent pressure resistance and can be suitably used as a package for storing food, beverages, medicines, hair care products, cosmetics, and the like.

[0027] [Laminate] Fig. 6 is a cross-sectional view showing an example of a laminate included in at least one of the first laminate section 301 and the second laminate section 302. Fig. 6 shows a cross-section along the lamination direction (thickness direction) of the laminate 305. The laminate 305 includes, in this order, a base film 10, a primer layer 40, an electrostatic ink layer 50, an adhesive layer 30, and a sealant layer 20. The primer layer 40 and the electrostatic ink layer 50 are in contact with each other, and the electrostatic ink layer 50 and the adhesive layer 30 are in contact with each other.

[0028] The substrate film 10 may have a flexible substrate. The flexible substrate may include, for example, one or both of a metal foil such as an aluminum foil and a thermoplastic polymer in the form of a film. Examples of the flexible substrate include biaxially oriented polypropylene (BOPP), polyethylene terephthalate (PET), oriented polyamide (OPA), solid polypropylene (CPP), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), and nylon (NY) film.

[0029] The base film 10 may include, for example, a vapor deposition film (transparent vapor deposition film) having a resin layer such as a PET film and a barrier layer (vapor deposition layer) on the resin layer. This can improve the sealing performance of the package 200. Examples of the barrier layer include a metal foil, a vapor deposition layer of a metal (e.g., aluminum) or a metal oxide (e.g., silica or alumina), and the like. The thickness of the base film 10 may be 7 to 150 μm, 10 to 100 μm, or 12 to 80 μm. A specific example of the transparent vapor deposition film is a transparent vapor deposition PET film in which a transparent vapor deposition layer is formed on a PET film. The base film 10 may include a nylon film such as a barrier nylon film.

[0030] The primer layer 40 may contain a resin. Examples of the resin include polyvinyl alcohol resin, cellulose-based resin, polyester, polyamine, polyethyleneimine resin, polyamide resin, polyurethane, polyacrylic polymer, hydroxyl-containing resin, carboxyl-containing resin, and amine-based polymer. By having the primer layer 40, printing of the electrostatic ink composition using a digital printer can be smoothly performed. In addition, the adhesion of the electrostatic ink layer 50 to the primer layer 40 can be improved. The application amount of the resin constituting the primer layer 40 is, for example, 0.01 to 1.5 g / m. 2 and may be 0.05 to 1.0 g / m 2 may be also possible.

[0031] The electrostatic ink layer 50 may be composed of an electrostatic ink composition. The electrostatic ink layer 50 is provided by electrostatic printing using a digital printer. The electrostatic ink layer 50 may be provided so as to cover a part of the surface of the primer layer 40. In other words, the electrostatic ink layer 50 may be provided so as to be interspersed between the primer layer 40 and the adhesive layer 30. This allows the laminate 305 to have blank areas.

[0032] The electrostatic ink layer 50 may be of a single color, or may be formed by laminating a plurality of electrostatic ink compositions having different colors. The electrostatic ink layer 50 and the adhesive layer 30 are adjacent to each other. In FIG. 6, the heights of the plurality of electrostatic ink layers 50 are the same, but this is not limited thereto. The electrostatic ink layer 50 may be a plurality of layers, or may be continuous into one layer. In FIG. 6, the electrostatic ink layer 50 is interrupted in the lateral direction. The interrupted portion of the electrostatic ink layer 50 becomes a blank portion. The electrostatic ink layer 50 may be a laminate formed without interruption in the lateral direction, and may not have a portion where the adhesive layer 30 and the primer layer 40 are in direct contact with each other.

[0033] The electrostatic ink composition constituting the electrostatic ink layer 50 is an ink composition used in liquid electrophotographic printing, i.e., electrostatic printing, and is printed on the primer layer 40. The electrostatic ink composition may contain a colorant or pigment such as a dye, and a resin. In addition to these, the electrostatic ink composition may also contain a carrier fluid or carrier liquid. It may further contain a charge director, a charge adjuvant, a surfactant, a viscosity modifier, an emulsifier, and other additives. It may also contain a component that permeates through the adhesive layer 30 (e.g., a polyisocyanate component).

[0034] The thickness of the electrostatic ink layer 50 can be adjusted by changing the ink coverage. The ink coverage represents the ratio of the dot area per unit area. For example, when a certain area is uniformly printed in a single color, the ink coverage is 100%. On the other hand, the ink coverage of an area where no printing is performed (plain area) is 0%. The ink coverage can be calculated based on these two. For example, the ink coverage can be 200% when the ink is applied once, and 300% when the ink is applied twice. In this way, the ink coverage can be increased by increasing the number of times the ink is applied. When only half of the entire area is printed once, the ink coverage is 50%. When printing is performed using ink of multiple colors, the ink coverage can be calculated for each color ink, and the total of the ink coverages can be used as the ink coverage of the target electrostatic ink layer 50. The ink coverage is set by a digital printer (e.g., HP's Indigo 20000 label and packaging digital printer) and can be adjusted by specifying a desired value in the ink coverage setting. The ink coverage on the printing surface 52 can be confirmed by observing the printing surface 52 with an optical microscope.

[0035] The ink coverage of the electrostatic ink layer 50 may be 500% or less, 400% or less, or 300% or less. By having the ink coverage in this range, the adhesive strength of the electrostatic ink layer 50 can be improved while the freedom of design can be improved by using a plurality of inks. The ink coverage of the electrostatic ink layer 50 may be 0% or more, 10% or more, 100% or more, or 200% or more. By having the ink coverage of the electrostatic ink layer 50 in this range, the freedom of design of the package can be further improved. The range of the ink coverage may be, for example, 0 to 500%, 10 to 500%, 100 to 400%, or 100 to 300%.

[0036] The thickness of the adhesive layer 30 may be 0.5 to 5 μm, 0.6 to 3 μm, or 0.8 to 2 μm, thereby achieving a good balance between adhesive strength and design.

[0037] The thickness of each layer constituting the laminate 305 can be measured by observing a cross section of the laminate 305 with a scanning electron microscope (SEM).

[0038] The adhesive layer 30 is composed of a solventless adhesive composition, a cured product thereof, or a mixture thereof. The adhesive composition may be a two-component curing type. The adhesive layer 30 contains two components, a polyisocyanate component and a polyol component. These components may at least partially react with each other to form a cured product. The cured product may contain polyurethane. The adhesive layer 30 containing the above two components and the electrostatic ink layer 50 are in direct contact with each other.

[0039] The polyisocyanate component contains a hexamethylene diisocyanate derivative (hereinafter, sometimes referred to as an "HDI derivative"). This increases the cohesive force of the electrostatic ink layer 50, and increases the adhesive strength of the adhesive layer 30. The HDI derivative may be a bifunctional derivative of hexamethylene diisocyanate. The HDI derivative is an aliphatic diisocyanate, and is more likely to penetrate into the electrostatic ink layer 50 than aromatic diisocyanates. This allows the electrostatic ink layer 50 and the adhesive layer 30 to blend well with each other, improving the crosslinking effect of the adhesive layer 30 and the electrostatic ink layer 50. This improves the adhesion between the electrostatic ink layer 50 and the adhesive layer 30.

[0040] The HDI derivative may be a trifunctional derivative of HDI (hexamethylene diisocyanate). Such a trifunctional derivative penetrates the electrostatic ink layer 50 and crosslinks with the components of the electrostatic ink layer 50. This further increases the cohesive force of the electrostatic ink layer 50, and further increases the adhesive strength of the adhesive layer 30. By including both a bifunctional derivative and a trifunctional derivative as the HDI derivative, the HDI derivative can be sufficiently penetrated into the electrostatic ink layer 50 and the crosslinking reaction with the components of the electrostatic ink layer 50 can be further advanced, so that the adhesive strength of the adhesive layer 30 can be maintained sufficiently high even when the electrostatic ink layer 50 is thick.

[0041] In the adhesive layer 30 (adhesive composition), the content of the trifunctional derivative of HDI may be higher than the content of the bifunctional derivative of HDI. This allows the crosslinking reaction to proceed sufficiently in the adhesive layer 30 and the electrostatic ink layer 50, improving the strength of the adhesive layer 30 and the electrostatic ink layer 50, and allowing the adhesive layer 30 and the electrostatic ink layer 50 to have a sufficiently high adhesive force. From this viewpoint, the mass ratio of the trifunctional derivative to the total of the bifunctional derivative and the trifunctional derivative may be 55 mass% or more, or may be 60 mass% or more. On the other hand, from the viewpoint of maintaining the flexibility of the adhesive layer 30 and the electrostatic ink layer 50, the mass ratio of the trifunctional derivative to the total of the bifunctional derivative and the trifunctional derivative may be 85 mass% or less, 80 mass% or less, or 75 mass% or less. An example of the mass ratio of the trifunctional derivative to the total of the bifunctional derivative and the trifunctional derivative is 55 to 85 mass%.

[0042] Examples of HDI derivatives include HDI multimers (e.g., dimers, trimers, pentamers, heptamers, etc.), biuret modified products (e.g., biuret modified products produced by the reaction of HDI with water, tertiary alcohols, or amines), allophanate modified products (e.g., allophanate modified products produced by the reaction of HDI with alcohols), urea modified products (e.g., urea modified products produced by the reaction of HDI with diamines), oxadiazinetrione (e.g., oxadiazinetrione produced by the reaction of HDI with carbon dioxide), carbodiimide modified products (carbodiimide modified products produced by decarboxylation condensation reaction of HDI), polyol modified products, etc. Also, an adduct of HDI and trimethylolpropane may be used.

[0043] The content of the HDI derivative in the polyisocyanate component may be 15% by mass or more, 20% by mass or more, or 25% by mass or more. This allows the above-mentioned effects to be fully exhibited. The content of the HDI derivative in the polyisocyanate component may be 60% by mass or less, 50% by mass or less, or 40% by mass or less. An example of the content of the HDI derivative in the polyisocyanate component is 15 to 60% by mass.

[0044] The polyisocyanate component may further contain a polyisocyanate having two or more isocyanate groups in one molecule, which is different from the HDI derivative. This allows the laminate 305 to be flexibly designed according to the desired properties. Examples of such polyisocyanate monomers include aromatic diisocyanates, aromatic alicyclic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates.

[0045] Aromatic diisocyanates are highly reactive and easily cured, which allows the laminate 305 to be produced quickly. Examples of aromatic aliphatic diisocyanates include m- or p-phenylene diisocyanate or a mixture thereof, 2,4- or 2,6-tolylene diisocyanate or a mixture thereof (TDI), 4,4'-, 2,4'-, or 2,2'-diphenylmethane diisocyanate or a mixture thereof (MDI), 4,4'-toluidine diisocyanate (TODI), 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate (NDI), and the like.

[0046] Examples of the aromatic aliphatic diisocyanate include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof (XDI), 1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof (TMXDI), ω,ω'-diisocyanato-1,4-diethylbenzene, and the like.

[0047] Examples of the aliphatic diisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, 1,2-, 2,3- or 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, and the like.

[0048] Examples of alicyclic diisocyanates include 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate; IPDI), 4,4'-, 2,4'-, or 2,2'-dicyclohexylmethane diisocyanate or a mixture thereof (hydrogenated MDI), methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane or a mixture thereof (hydrogenated XDI), and the like.

[0049] The polyisocyanate component may contain a derivative of the polyisocyanate monomer (polyisocyanate derivative). Examples of the polyisocyanate derivative include polyisocyanate derivatives (e.g., dimers, trimers, pentamers, heptamers, etc.), allophanate modified products (e.g., allophanate modified products produced by the reaction of a polyisocyanate monomer with alcohols, etc.), biuret modified products (e.g., biuret modified products produced by the reaction of a polyisocyanate monomer with water or amines, etc.), urea modified products (e.g., urea modified products produced by the reaction of a polyisocyanate monomer with a diamine, etc.), oxadiazinetrione (e.g., oxadiazinetrione produced by the reaction of a polyisocyanate monomer with carbon dioxide gas, etc.), and carbodiimide modified products (carbodiimide modified products produced by decarboxylation condensation reaction of a polyisocyanate monomer, etc.).

[0050] The polyisocyanate component may include an isocyanate-terminated prepolymer. The isocyanate-terminated prepolymer is a urethane prepolymer having at least two isocyanate groups at the molecular end. The urethane prepolymer can be obtained by subjecting at least one member selected from the group consisting of a polyisocyanate monomer, a polyisocyanate derivative, and an isocyanate-terminated prepolymer to a urethane reaction with a polyol.

[0051] The polyol component may contain at least one selected from the group consisting of polyester polyols and polyether polyols. Among these, from the viewpoint of reducing production costs and suppressing hydrolysis, polyether polyol may be contained.

[0052] The polyether polyol may be a polyalkylene oxide. For example, it may be obtained by addition reaction of an alkylene oxide such as ethylene oxide and / or propylene oxide with a low molecular weight polyol as an initiator. Specific examples include polyethylene glycol, polypropylene glycol, and polyethylene polypropylene glycol (random or block copolymer). In addition, for example, polytetramethylene ether glycol obtained by ring-opening polymerization of tetrahydrofuran may be mentioned.

[0053] The polyester polyol can be obtained, for example, by a condensation reaction or an ester exchange reaction between a polyhydric alcohol and a polybasic acid, its alkyl ester, its acid anhydride, or its acid halide. Examples of the polyhydric alcohol include a low molecular weight diol, a low molecular weight triol, and a low molecular weight polyol having four or more hydroxyl groups.

[0054] Examples of low molecular weight diols include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, neopentyl glycol, 1,6-hexanediol, 2,2-diethyl-1,3-propanediol, 3,3-dimethylolheptane, and 2-ethyl-2-butyl-1,3-propanediol.

[0055] Examples of low molecular weight triols include glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6-hexanetriol, trimethylolethane, trimethylolpropane, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-(hydroxymethyl)pentane, and 2,2-bis(hydroxymethyl)-3-butanol.

[0056] Examples of low molecular weight polyols having four or more hydroxyl groups include tetramethylolmethane, pentaerythritol, dipentaerythritol, D-sorbitol, xylitol, D-mannitol, and D-mannite.

[0057] Examples of the alkyl ester of a polybasic acid include methyl ester and ethyl ester of a polybasic acid. Examples of the acid anhydride include acid anhydrides derived from a polybasic acid. For example, oxalic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, 2-alkyl (C12-18) succinic anhydride, tetrahydrophthalic anhydride, and trimellitic anhydride can be mentioned.

[0058] The acid halide may be an acid halide derived from the above-mentioned polybasic acid, such as oxalic acid dichloride, adipic acid dichloride, or sebacic acid dichloride.

[0059] In the adhesive layer 30 (adhesive composition), the mass ratio of the polyisocyanate component may be higher than the mass ratio of the polyol component. Specifically, the mass ratio of the polyisocyanate component to the polyol component may be 1 or more, 1.2 or more, or 1.4 or more. In this way, by increasing the mass ratio of the polyisocyanate component to the polyol component, the curing reaction is promoted and the adhesion and curing process can be sufficiently shortened. From the same viewpoint, the mass ratio of the polyisocyanate component to the polyol component may be 4 or less, or 3 or less. One example of the mass ratio of the polyisocyanate component to the polyol component is 1 to 4.

[0060] Examples of the sealant layer 20 include a non-oriented polypropylene film (CPP film), a linear low density polyethylene film (LLDPE film), and a low density polyethylene film (LDPE). The thickness of the sealant layer 20 may be 10 to 150 μm, 20 to 100 μm, or 30 to 80 μm.

[0061] FIG. 7 is a cross-sectional view showing another example of the laminate. FIG. 7 shows a cross-section along the lamination direction (thickness direction) of the laminate 310. The laminate 310 has a base film 10, a primer layer 40, an electrostatic ink layer 51, a first adhesive layer 30, an intermediate layer 21, a second adhesive layer 31, and a sealant layer 20 in this order. The primer layer 40 and the electrostatic ink layer 51 are in contact with each other, and the electrostatic ink layer 51 and the first adhesive layer 30 are in contact with each other. The electrostatic ink layer 51 is formed so as to cover the entire primer layer 40. Therefore, the laminate 310 does not have a plain portion. However, in a modified example, the electrostatic ink layer 51 may be interrupted like the electrostatic ink layer 50 of the laminate 305 in FIG. 6, and the laminate 310 may have a plain portion.

[0062] The intermediate layer 21 may have a flexible substrate. Examples of the flexible substrate include biaxially oriented polypropylene (BOPP), polyethylene terephthalate (PET), oriented polyamide (OPA), and nylon films. The intermediate layer 21 may be, for example, a vapor deposition film (transparent vapor deposition film) including a resin layer such as a PET film and a barrier layer (vapor deposition layer) on the resin layer, or may be a metal foil or a barrier film. Examples of the metal foil include aluminum foil.

[0063] The first adhesive layer 30 and the second adhesive layer 31 may have the same components and thickness as the adhesive layer 30 in Fig. 6. The material and thickness of the sealant layer 20 may be as described for the sealant layer 20 in the laminate 305 in Fig. 6. The other layers of the laminate 310 may be as described for the laminate 305 in Fig. 6.

[0064] The adhesive layer 30 (first adhesive layer 30) and / or the second adhesive layer 31 (adhesive composition) may contain a surface modifier that improves adhesion between the primer layer 40 or the electrostatic ink layer 51, the intermediate layer 21, and the sealant layer 20. When the intermediate layer 21 is a barrier layer such as a metal, the adhesive strength and seal strength between the adhesive layer 30, 31 and the barrier layer can be further increased. When the barrier layer has a metal layer (aluminum layer) such as a metal foil (aluminum foil) or a metal film (aluminum film), the adhesive layer 30, 31 (adhesive composition) contains a surface modifier, thereby further improving adhesion to the metal layer.

[0065] Examples of the surface modifier include those containing at least one selected from sulfamic acid, phosphoric acid, nitric acid, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, and ethyl hydroxyethyl cellulose.

[0066] The adhesive composition constituting the adhesive layer 30 may contain optional components such as additives in addition to the polyisocyanate component and the polyol component. Examples of additives include antioxidants, ultraviolet absorbers, light stabilizers, fillers, silane coupling agents, epoxy resins, catalysts, coating property improvers, leveling agents, nucleating agents, lubricants, release agents, defoamers, plasticizers, surfactants, pigments, dyes, organic fine particles, inorganic fine particles, antifungal agents, and flame retardants. The adhesive composition is solvent-free and does not contain a solvent such as an organic solvent. This reduces the environmental load and sufficiently improves the working environment. The solvent-free adhesive composition is used by heating during coating.

[0067] The adhesive strength of the adhesive layers 30, 31 in the laminates 305, 310 may be 1.0 N / 15 mm width or more, 1.4 N / 15 mm width or more, or 1.5 N / 15 mm width or more. The adhesive strength of the adhesive layers 30, 31 mainly depends on the cohesive strength of the electrostatic ink layer 50 and the adhesive strength of the adhesive layers 30, 31. If the cohesive strength of the electrostatic ink layer 50 and the adhesive strength of the adhesive layers 30, 31 are high, the adhesive strength of the adhesive layers 30, 31 can be sufficiently high. The packaging bag 100 composed of the laminates 305, 310 having such adhesive strength can suppress the peeling of the laminates 305, 310 due to the external force applied when tearing. Therefore, the packaging bag 100 can be opened cleanly. The adhesive strength of the adhesive layers 30, 31 may be 5.0 N / 15 mm width or less.

[0068] The adhesive strength in the present disclosure is a peel adhesive strength measured in accordance with the description in JIS K 6854-1:1999 "Adhesives-Peel Adhesion Strength Test Method-Part 1: 90 degree peel". Specifically, it can be measured by the method described in the examples of the present disclosure.

[0069] The laminate of the present disclosure is not limited to the structures of Figs. 6 and 7. For example, it may have the following laminate structure. In each example, the rightmost layer is the sealant layer 20. In each example, each layer is arranged in order from left to right. The following third adhesive layer may be the same adhesive layer as the adhesive layer 30 (first adhesive layer) and the second adhesive layer 31, or may be a different adhesive layer from these. The layer structure of the laminate is not limited to the following examples.

[0070] Example 1) PET film / primer layer / electrostatic ink layer / adhesive layer / LLDPE film (linear low-density polyethylene film) Example 2) Nylon film / primer layer / electrostatic ink layer / adhesive layer / LLDPE film Example 3) Transparent vapor-deposited PET film / primer layer / electrostatic ink layer / adhesive layer / CPP film (non-oriented polypropylene film) Example 4) Barrier nylon film / primer layer / electrostatic ink layer / adhesive layer / CPP film Example 5) Transparent vapor-deposited PET film / primer layer / electrostatic ink layer / first adhesive layer / PET film / second adhesive layer / CPP film Example 6) Transparent vapor-deposited PET film / primer layer / electrostatic ink layer / first adhesive layer / nylon film / second adhesive layer / CPP film Example 7) Transparent vapor-deposited PET film / primer layer / electrostatic ink layer / 1st adhesive layer / PET film / 2nd adhesive layer / nylon film / 3rd adhesive layer / CPP film Example 8) Transparent vapor-deposited PET film / primer layer / electrostatic ink layer / 1st adhesive layer / nylon film / 2nd adhesive layer / PET film / 3rd adhesive layer / CPP film Example 9) Transparent vapor-deposited PET film / primer layer / electrostatic ink layer / first adhesive layer / PET film / second adhesive layer / PET film / third adhesive layer / CPP film Example 10) OPP film / primer layer / electrostatic ink layer / adhesive layer / CPP film Example 11) OPP film / primer layer / electrostatic ink layer / adhesive layer / LLDPE film Example 12) Nylon film / primer layer / electrostatic ink layer / adhesive layer / CPP film Example 13) PET film / primer layer / electrostatic ink layer / adhesive layer / CPP film Example 14) PET film / primer layer / electrostatic ink layer / first adhesive layer / nylon film / second adhesive layer / LLDPE film Example 15) PET film / primer layer / electrostatic ink layer / first adhesive layer / aluminum foil / second adhesive layer / LDPE film Example 16) PET film / primer layer / electrostatic ink layer / first adhesive layer / aluminum foil / second adhesive layer / nylon film / third adhesive layer / LLDPE film

[0071] <Manufacturing method of packaging body> A method for manufacturing the package 200 will be described below. A pair of laminates 305 or laminates 310 cut into a predetermined shape is prepared as the package material. The laminates 305 and 310 may be a pair of laminates. For example, the laminate 305 may be the first laminate part 301, and the laminate 310 may be the second laminate part 302.

[0072] A manufacturing method for the packaging bag 100 and the packaging body 200 includes a step of bonding at least a portion of the outer edges of the first laminated portion 301 and the second laminated portion 302 together to form a sealed portion 101, a step of forming a storage portion 102 between the first laminated portion 301 and the second laminated portion 302, and a step of sealing the contents in the storage portion 102.

[0073] In the process of forming the seal portion 101, the sealant layers 20 provided on one side of the first laminate portion 301 and the second laminate portion 302 are placed opposite each other, and the sealant layers 20 are bonded to each other at least a portion of the outer edges of the first laminate portion 301 and the second laminate portion 302.

[0074] Next, in the process of forming the storage section 102, the seal section 101 is formed at the upper end and the side end to form the storage section 102 surrounded by the seal section 101 in a U-shape between the first laminated section 301 and the second laminated section 302. In this manner, a packaging bag 110 is obtained in which only the upper end (or only the lower end) is unsealed, as shown in Fig. 8. In some examples, the packaging bag of this embodiment may have a portion of the periphery unsealed as shown in Fig. 8.

[0075] Next, in the process of sealing the contents in the storage section 102, the contents are filled from the upper end (or lower end) in an unsealed state in Fig. 8, and the first laminated section 301 and the second laminated section 302 are bonded to each other at the upper end (or lower end), and a seal section 101 is formed at the upper end (or lower end) to seal it. After that, opening means 120 including an easy-open processing section 124 and a half-cut line 121 may be formed. In this manner, a package 200 including a packaging bag 100 and the contents stored therein can be manufactured.

[0076] At least one of the first laminated portion 301 and the second laminated portion 302 in the obtained package 200 has an electrostatic ink layer 50, 51 formed by digital printing, and a solvent-free adhesive layer 30, 31. The compositions of the electrostatic ink layer and the adhesive layer are as described above. In addition, when a pressure resistance test is performed on the storage portion 102 of the package 200 by applying a load of 70 kg for 3 minutes, the length L of the lift generated in the sealed portion 101 is 0.5 mm or less, based on the boundary between the sealed portion 101 and the storage portion 102 before the load is applied. The procedure of the pressure resistance test is as described above. Since the package 200 has an electrostatic ink layer and a solvent-free adhesive composition, it has excellent pressure resistance while sufficiently reducing the environmental load, and has a high degree of design freedom, which can increase consumer purchasing motivation.

[0077] <Method of manufacturing laminate> A manufacturing method for the laminate 305, which is an example of the first laminate section 301 or the second laminate section 302, may include the steps of forming a primer layer 40 on one side of the base film 10, printing an electrostatic ink composition on the primer layer 40 to form an electrostatic ink layer 50 and obtain a printed surface 52, adhering the printed surface 52 to one side of the film-like sealant layer 20 using a solvent-free adhesive composition containing a polyisocyanate component and a polyol component, and curing or semi-curing the adhesive composition to form the adhesive layer 30.

[0078] The primer layer 40 may be formed on one side of the substrate film 10 by flexographic printing or gravure printing. The primer layer 40 may be formed by crosslinking a resin raw material with a crosslinking agent. Crosslinking may be performed by irradiating with ultraviolet light, heat, ionizing radiation such as an electron beam, or non-ionizing radiation such as microwave radiation. The printing of the electrostatic ink composition may be performed by electrostatic printing using a digital printer. As the digital printer, for example, the "Indigo 20000 label and packaging digital printer" manufactured by HP may be used. In this manner, the electrostatic ink layer 50 is formed, and the printing surface 52 is obtained.

[0079] The adhesive composition may be used to bond the printed surface 52 and one side of the sealant layer 20 together as follows. For example, a roll coater made up of a combination of multiple rolls is used to apply the adhesive composition, which is heated to about 40 to 90°C and melted, to the printed surface 52 of the substrate film 10 or one side of the sealant layer 20. Thereafter, the adhesive composition on the printed surface 52 or the adhesive composition on the sealant layer 20 is placed face to face with the bonding surface of the other substrate, and the adhesive composition is bonded to the bonding surface of the other substrate using a nip roll. The raw roll thus obtained is aged. The curing of the adhesive composition progresses through aging, and the adhesive layer 30 is formed. In this way, a laminate 305 having the substrate film 10, the primer layer 40, the electrostatic ink layer 50, the adhesive layer 30, and the sealant layer 20 in this order can be manufactured. The aging temperature may be 20 to 50°C, and the aging time may be 0.5 to 5 days.

[0080] When manufacturing the laminate 310, the sealant layer 20 is replaced with the intermediate layer 21 in the above-mentioned process, and the adhesive composition that has been heated to, for example, about 40 to 90°C and melted is further applied to the surface of the intermediate layer 21 opposite to the adhesive layer 30. The application of the adhesive composition here may also be performed by a roll coater combining a plurality of rolls. Thereafter, the applied adhesive composition and the sealant layer 20 are bonded to each other using a nip roll so that the adhesive composition and the sealant layer 20 face each other. The raw roll thus obtained is aged. The adhesive composition is cured or semi-cured by a urethane reaction by aging, and the second adhesive layer 31 containing a cured product is formed. Aging to obtain the adhesive layer 30 and the adhesive layer 31 may be performed simultaneously. In this way, the laminate 310 having the base film 10, the primer layer 40, the electrostatic ink layer 50, the first adhesive layer 30, the intermediate layer 21, the second adhesive layer 31, and the sealant layer 20 in this order can be manufactured. The laminates according to the respective modified examples can be manufactured in the same manner as the laminates 305 and 310.

[0081] The laminates 305 and 310 thus manufactured have the configurations and properties as described above. The contents of the description of the laminates 305 and 310 and their modified examples also apply to the above-mentioned example of the manufacturing method.

[0082] The laminates 305, 310 have a printed surface 52 printed by digital printing (electrostatic printing), which allows for a high degree of freedom in design. In addition, the use of a solvent-free adhesive composition allows for a sufficient reduction in environmental impact. And, even though such a solvent-free adhesive composition is used, the laminates 305, 310 have even better pressure resistance.

[0083] Although several examples have been described above, the present embodiment is not limited to the above examples. For example, the shape of the package is not limited to a four-sided bag, and may be, for example, a two-sided bag, a three-sided bag, a two-sided bag, a two-sided bag, or a standing pouch.

[0084] The present disclosure includes the following embodiments and modifications thereof. [1] A packaging bag having a seal portion in which at least a portion of the outer edges of a first laminated portion and a second laminated portion are bonded together, and a storage portion formed between the first laminated portion and the second laminated portion; A package comprising: At least one of the first laminate section and the second laminate section includes a laminate having a base film, a primer layer, an adhesive layer, and a sealant layer in this order, and an electrostatic ink layer is interposed at least on one side between the primer layer and the adhesive layer, The adhesive layer comprises a solventless adhesive composition containing a polyisocyanate component including a derivative of hexamethylene diisocyanate and a polyol component, a cured product thereof, or a mixture thereof; A package in which, when a load of 70 kg is applied to the storage section for 3 minutes, the length L of the floating that occurs in the sealed section is 0.5 mm or less, based on the boundary line between the sealed section and the storage section before the load is applied. [2] The packaging body described in [1], wherein the ink coverage rate of the electrostatic ink layer is 500% or less. [3] The packaging body described in [1] or [2], wherein the adhesive strength of the adhesive layer is 1.0 N / 15 mm width or more. [4] The package described in any one of [1] to [3], wherein the seal strength of the sealed portion is 15.0 N / 15 mm width or more. [5] The package described in any one of [1] to [4], wherein the polyisocyanate component further contains a polyisocyanate different from the derivative of hexamethylene diisocyanate. [6] The packaging body according to any one of [1] to [5], wherein a mass ratio of the polyisocyanate component to the polyol component is 1 or more. [7] The package according to any one of [1] to [6], wherein the polyol component contains a polyether polyol. [8] The package according to any one of [1] to [7], wherein the derivative of hexamethylene diisocyanate includes a bifunctional derivative of hexamethylene diisocyanate and a trifunctional derivative of hexamethylene diisocyanate. [9] The package according to [8], wherein the content of the trifunctional derivative is higher than the content of the bifunctional derivative.

[10] The packaging body according to any one of [1] to [9], wherein the adhesive composition contains a surface modifier.

[11] A step of bonding at least a part of the outer edges of the first laminated portion and the second laminated portion to each other to form a seal portion; and sealing an object to be contained in a container portion between the first laminate portion and the second laminate portion, At least one of the first laminate section and the second laminate section includes a laminate having a base film, a primer layer, an adhesive layer, and a sealant layer in this order, and an electrostatic ink layer is interposed at least on one side between the primer layer and the adhesive layer, The adhesive layer comprises a solventless adhesive composition containing a polyisocyanate component including a derivative of hexamethylene diisocyanate and a polyol component, a cured product thereof, or a mixture thereof; A method for manufacturing a packaging body, in which when a load of 70 kg is applied to the storage section for 3 minutes, the length L of the floating that occurs in the sealed section is 0.5 mm or less, based on the boundary line between the sealed section and the storage section before the load is applied.

[12] forming the primer layer on one side of the base film; printing the electrostatic ink composition on the primer layer to obtain a printed surface; a step of adhering the printed surface and one surface of a sealant layer using the solvent-free adhesive composition; and curing or semi-curing the solventless adhesive composition to obtain at least one of the first laminate portion and the second laminate portion. EXAMPLES

[0085] The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0086] Example 1 [Laminated body production] A commercially available nylon film (NY film, manufactured by Unitika Ltd., product name: Emblem ON, thickness: 15 μm) was prepared as the substrate film, and a commercially available linear low-density polyethylene film (LLDPE film, thickness: 40 μm) was prepared as the sealant layer. An aqueous primer resin (resin containing polyethyleneimine, manufactured by Michelman, product name: DP050) was applied to one side of the NY film to form a primer layer. At this time, the amount of aqueous polyethyleneimine applied was 0.10 to 0.18 g / m 2 The water-based primer resin was applied to the NY film so that the thickness of the primer resin was 100 μm.

[0087] An electrostatic ink composition was applied to the surface of the primer layer using a digital printer (HP Indigo 20000 label and package digital printer) to form an electrostatic ink layer. The ink coverage of the electrostatic ink layer was 200% (cyan (C) 100% + white (W) 100%), 300% (magenta (M) 100% + yellow (Y) 100% + white (W) 100%), or 300% (cyan (C) 100% + magenta (M) 100% + white (W) 100%), and electrostatic ink layers with three different ink coverages were prepared. As the electrostatic ink composition, an electrostatic ink composition (HP Indigo Electroink) containing a thermoplastic resin containing a copolymer of ethylene acrylic acid and ethylene methacrylic acid was used.

[0088] As the polyisocyanate component, a derivative of diphenylmethane isocyanate (MDI) (MDI derivative, manufactured by Mitsui Chemicals, Inc.), a derivative of hexamethylene diisocyanate (HDI derivative I, manufactured by Mitsui Chemicals, Inc.), and a derivative of hexamethylene diisocyanate (HDI derivative II, manufactured by Mitsui Chemicals, Inc.) were prepared. The HDI derivative I contained a bifunctional derivative of hexamethylene diisocyanate. The HDI derivative II contained a trifunctional derivative of hexamethylene diisocyanate. The MDI derivative, HDI derivative I, and HDI derivative II were mixed in a mass ratio of MDI derivative:HDI derivative I:HDI derivative II = 100:14:28 to prepare a polyisocyanate component.

[0089] As the polyol component, polyether polyol (manufactured by Mitsui Chemicals, Inc., product name: XRN-21B) was prepared. The polyol component and the polyisocyanate component were mixed so that the mass ratio of the polyol component to the polyisocyanate component was 142 / 65 (≒2.18), and a surface modifier was further added to prepare a solventless adhesive composition containing the surface modifier. This adhesive composition was heated to about 60°C and applied to one side of the electrostatic ink layer formed on the substrate film using a roll coater to form a coating film having a predetermined thickness. The amount of application of the adhesive composition was about 2.0 g / m 2The coating film and the sealant layer (LLDPE film) were overlapped so that they faced each other, and the electrostatic ink layer on the base film and the sealant layer were bonded via the coating film (adhesive composition) using a nip roll. Then, aging was performed at 45°C for 2 days to cure the adhesive composition. By this method, a laminate having the base film, primer layer, electrostatic ink layer, adhesive layer, and sealant layer in this order was obtained.

[0090] [Adhesive layer thickness] The cross section of the laminate was observed with a scanning electron microscope (SEM) to measure the thickness of the adhesive layer, which was found to be 1 to 2 μm.

[0091] [Adhesive strength measurement] The adhesive strength of the prepared laminate was measured according to JIS K 6854-1:1999. Specifically, among the prepared laminates, those with an ink coverage of 200% (cyan (C) 100% + white (W) 100%) and 300% (magenta (M) 100% + yellow (Y) 100% + white (W) 100%) were cut into 15 mm widths to obtain measurement samples. After peeling between the base film and the sealant layer at the end of the measurement sample, the peel adhesion strength of the laminate was measured using a tensile tester under conditions of an angle of 90°, a tensile speed of 300 mm / min, and room temperature. This peel adhesion strength was defined as the adhesive strength. The measurement results are shown in Table 1.

[0092] [Seal strength measurement] A pair of laminates was heat-sealed so that the sealant layers (LLDPE films) overlapped each other to form a sealed portion. The heat-sealing conditions were 160°C, 0.2 MPa, and 0.5 seconds. This caused the LLDPE film to be welded together to prepare a 15 mm wide measurement sample. The ink coverage of the measurement sample was 200% (cyan (C) 100% + white (W) 100%) or 300% (magenta (M) 100% + yellow (Y) 100% + white (W) 100%). The seal strength of the seal portion of the measurement sample prepared was measured in accordance with JIS K 7127:1999. The measurement was performed using a tensile tester under the conditions of a peel angle of 90°, a tensile speed of 300 mm / min, and room temperature (20°C), to measure the peel strength between the heat seals. This peel strength was taken as the seal strength. The measurement results were as shown in Table 1.

[0093] [Packaging Creation] The laminates with ink coverage of 200% (cyan (C) 100% + white (W) 100%) and 300% (cyan (C) 100% + magenta (M) 100% + white (W) 100%) were cut into 70 mm x 70 mm pieces, and two pieces were prepared. The sealant layers (LLDPE films) of the two cut laminates with the same ink coverage were overlapped, and three sides of the outer edge were bonded by heat sealing to produce a packaging bag having a 15 mm wide seal part and a storage part between the two laminates. 18 mL of water was poured into the storage part from the remaining side of the produced packaging bag that was not heat sealed to fill the storage part with water, and the remaining side that was not heat sealed was heat sealed to seal the water in the storage part. At this time, air was prevented from being contained in the storage part. In this way, the package of Example 1 was produced. The heat sealing conditions were 160° C., 0.2 MPa, and 0.5 seconds using an impulse heat sealer (product name: FI-300-10WK, manufactured by Fuji Impulse Co., Ltd.).

[0094] [Pressure resistance measurement] The pressure resistance of the prepared package was measured in accordance with "10. Compression resistance test" of JIS Z 0238:1998 "Test method for heat-sealed flexible packaging and semi-rigid containers". Specifically, as shown in FIG. 3, a pressure plate and a weight were placed on the container part of the package placed on the sample support table so that a load of 70 kg was applied to the container part, and the package was left to stand for 3 minutes. The load was applied in a direction perpendicular to the sample support table (vertical direction). The length of the lifting that occurred on the sealed part was then evaluated. The length L of the lifting was measured by visually checking the part with the longest lifting length in the vertical direction toward the sealed part, using the boundary line between the sealed part and the container part as a reference, and measuring that length with a ruler, as shown in FIG. 5. For the package using the laminate with an ink coverage rate of 200%, three packages were prepared, and the pressure resistance of each package was measured. The measurement results are shown in Table 2. In Table 2, the items for which the pressure resistance was not measured are indicated by "-".

[0095] Comparative Example 1 A laminate was produced in the same manner as in Example 1, except that a commercially available solvent-free adhesive composition for gravure printing was used instead of the adhesive composition used in Example 1. This adhesive composition was prepared by blending a polyether polyol (manufactured by Toyo Morton Co., Ltd., product name: EA-N373B, hereinafter also referred to as "(A)") as a main agent and an aromatic polyisocyanate (manufactured by Toyo Morton Co., Ltd., product name: EA-N373A, hereinafter also referred to as "(B)") as a curing agent. The blending ratio (mass basis) of each component was (A):(B) = 50:100. The adhesive strength and seal strength were measured in the same manner as in Example 1. The measurement results are shown in Table 1.

[0096] Using the laminate produced in Comparative Example 1, a package was produced in the same manner as in Example 1. The pressure resistance was measured and the lift length L of the seal portion was measured in the same manner as in Example 1. The measurement results are shown in Table 2.

[0097] Comparative Example 2 An organic solvent-based adhesive composition with a solid content of 33% by mass was prepared by blending an aliphatic polyester polyol (manufactured by Mitsui Chemicals, Inc., product name: Takelac A626, hereinafter sometimes referred to as "(C)") as a base agent, a polyisocyanate (manufactured by Mitsui Chemicals, Inc., product name: Takenate A65, hereinafter sometimes referred to as "(D)") as a curing agent, and ethyl acetate as a solvent. The blending ratio (mass basis) of each component was (C):(D) = 16:1.

[0098] A primer layer was formed on a substrate film (NY film) in the same manner as in Example 1. Then, an electrostatic ink composition was applied to a part of the surface of the primer layer using a digital printer (Indigo20000 label and package digital printer manufactured by HP) to form an electrostatic ink layer. The ink coverage of the electrostatic ink layer was 200% (cyan (C) 100% + white (W) 100%), 300% (magenta (M) 100% + yellow (Y) 100% + white (W) 100%), or 300% (cyan (C) 100% + magenta (M) 100% + white (W) 100%), and electrostatic ink layers with three different ink coverages were prepared.

[0099] The organic solvent-based adhesive composition prepared as described above was applied to the electrostatic ink layer using a dry laminating device, and then hot air drying was performed to form a coating film consisting of only nonvolatile components. The coating amount of the nonvolatile coating film was about 2.0 g / m 2The coating film and the sealant layer (LLDPE film) used in Example 1 were overlapped so as to face each other, and the electrostatic ink layer and the sealant layer on the base film were bonded via the coating film using a nip roll. The coating film was then cured by aging at 40°C for 2 days. By such a dry lamination method, a laminate of Comparative Example 2 having a base film, a primer layer, an electrostatic ink layer, an adhesive layer, and a sealant layer in this order was obtained. The laminate of Comparative Example 2 differs from the laminate of Example 1 in that an organic solvent-based adhesive composition is used. The adhesive strength and seal strength of the laminate of Comparative Example 2 were measured using the same procedure as in Example 1. The measurement results are shown in Table 1.

[0100] Using the laminate produced in Comparative Example 2, a package was produced in the same manner as in Example 1. The pressure resistance was measured and the lift length L of the seal portion was measured in the same manner as in Example 1. The measurement results are shown in Table 2.

[0101] [Table 1]

[0102] [Table 2]

[0103] As shown in Table 1, the laminate of Example 1 showed higher adhesive strength than the laminates of Comparative Example 1 and Comparative Example 2 at all ink coverage rates. Moreover, the laminate of Example 1 showed higher seal strength than the laminate of Comparative Example 1 at all ink coverage rates, and showed a seal strength equivalent to that of Comparative Example 2, which used an organic solvent-based adhesive composition. Furthermore, as shown in Table 2, no lifting occurred in the package of Example 1 after the pressure resistance test. From these results, it was shown that the package of Example 1 has excellent pressure resistance equivalent to that of an organic solvent-based adhesive, even though it has an electrostatic ink layer and a solvent-free adhesive layer. Therefore, it was confirmed that a package with high strength can be obtained while using an electrostatic ink layer and a solvent-free adhesive layer that reduces environmental load. [Industrial Applicability]

[0104] According to the present disclosure, it is possible to provide a laminate including an electrostatic ink layer that has excellent pressure resistance while reducing the environmental impact, and a method for producing the same. [Explanation of symbols]

[0105] 100...packaging bag, 101...sealed portion, 102...storage portion, 110...packaging bag, 120...opening means, 121...half-cut line, 124...easy-open processing portion, 200...packaging body, 301...first laminated portion, 302...second laminated portion, 305, 310...laminated body, 400...sample support stand, 402...pressure plate, 405...weight, V...float, L...length of float, X...orthogonal direction, P...orthogonal direction, K...boundary line, 10...base film, 20...sealant layer, 21...intermediate layer, 30...adhesive layer (first adhesive layer), 31...adhesive layer (second adhesive layer), 40...primer layer, 50, 51...electrostatic ink layer, 52...printed surface.

Claims

1. A packaging bag including a seal portion in which at least a part of the outer edges of a first laminated portion and a second laminated portion are bonded together, and a storage portion formed between the first laminated portion and the second laminated portion; A package comprising: At least one of the first laminate section and the second laminate section includes a laminate having a base film, a primer layer, an adhesive layer, and a sealant layer in this order, and an electrostatic ink layer is interposed at least on one side between the primer layer and the adhesive layer, The adhesive layer comprises a solventless adhesive composition containing a polyisocyanate component including a derivative of hexamethylene diisocyanate and a polyol component, a cured product thereof, or a mixture thereof; A package in which, when a load of 70 kg is applied to the storage section for 3 minutes, the length L of the lift that occurs in the sealed section is 0.5 mm or less, based on the boundary line between the sealed section and the storage section before the load is applied.

2. 2. The package of claim 1, wherein the electrostatic ink layer has an ink coverage of 500% or less.

3. 3. The packaging body according to claim 1, wherein the adhesive layer has an adhesive strength of 1.0 N / 15 mm width or more.

4. The package according to claim 1 or 2, wherein the seal strength of the sealed portion is 15.0 N / 15 mm width or more.

5. 3. The package of claim 1 or 2, wherein the polyisocyanate component further comprises a polyisocyanate different from the derivative of hexamethylene diisocyanate.

6. The package according to claim 1 or 2, wherein a mass ratio of the polyisocyanate component to the polyol component is 1 or more.

7. The package of claim 1 or 2, wherein the polyol component comprises a polyether polyol.

8. The package according to claim 1 or 2, wherein the derivative of hexamethylene diisocyanate includes a bifunctional derivative of hexamethylene diisocyanate and a trifunctional derivative of hexamethylene diisocyanate.

9. The package according to claim 8 , wherein the content of the trifunctional derivative is higher than the content of the bifunctional derivative.

10. The package of claim 1 or 2, wherein the adhesive composition contains a surface modifier.

11. a step of bonding at least a part of an outer edge of the first laminated portion and the second laminated portion to each other to form a seal portion; and sealing an object to be contained in a container portion between the first laminate portion and the second laminate portion, At least one of the first laminate section and the second laminate section includes a laminate having a base film, a primer layer, an adhesive layer, and a sealant layer in this order, and an electrostatic ink layer is interposed at least on one side between the primer layer and the adhesive layer, The adhesive layer comprises a solventless adhesive composition containing a polyisocyanate component including a derivative of hexamethylene diisocyanate and a polyol component, a cured product thereof, or a mixture thereof; A method for manufacturing a packaging body, in which when a load of 70 kg is applied to the storage section for 3 minutes, the length L of the float that occurs in the sealed section is 0.5 mm or less, based on the boundary line between the sealed section and the storage section before the load is applied.

12. forming the primer layer on one side of the base film; printing an electrostatic ink composition on the primer layer to obtain a printed surface; a step of adhering the printed surface and one surface of a sealant layer using the solvent-free adhesive composition; and curing or semi-curing the solventless adhesive composition to obtain at least one of the first laminated portion and the second laminated portion.

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