Laminate and method for manufacturing a laminate

Abstract

To provide: a laminate including a paper substrate that has excellent ink adhesion at a part printed by a digital printing machine and has excellent heat resistance; and a method for manufacturing the laminate.SOLUTION: A laminate 10 includes a first substrate layer 11, an anchor coat layer 13, an adhesive layer 14, a second substrate layer 15, and a sealant layer 18, which are disposed in this order from an outer surface toward an inner surface. An electrostatic ink layer 12 is disposed on an inner surface side of the first substrate layer 11. The adhesive layer 14 is an extruded polyolefin resin layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to laminates and methods for manufacturing laminates. [Background technology]

[0002] Traditionally, printing on packaging materials has been done primarily using printing plates, such as gravure printing and flexographic printing. In recent years, digital printing, which enables small-lot printing, has been attracting attention. Digital printing does not require printing plates and can print directly, offering advantages such as short lead times and the ability to produce a wide variety of products.

[0003] A laminate comprising a first substrate, an adhesive layer, and a second substrate in that order, as a laminate including an electrostatic ink layer produced by digital printing, has been proposed, wherein the electrostatic ink layer is between at least one of the first substrate and the second substrate and the adhesive layer, and the adhesive layer uses a two-component adhesive containing a polymer of a polyol, polyisocyanate, and an epoxy compound (for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2021 / 024981 [Overview of the project] [Problems that the invention aims to solve]

[0005] Incidentally, while plastic packaging materials are superior in terms of moisture resistance and other properties, the increasing environmental concerns in recent years have led to a trend towards reducing the proportion of plastic base materials used, and there is a need for the development of packaging materials using paper base materials.

[0006] According to the inventors' research, the above-mentioned digital printing method has limitations in the ink materials that can be used, and therefore the adhesion and heat resistance of the digitally printed portion differ from those of conventional packaging materials with a paper base. [Means for solving the problem]

[0007] This disclosure is made in the context of these circumstances, and its purpose is to provide a laminate having a paper substrate with excellent ink adhesion to the portion printed by a digital printing press, as well as excellent adhesion and heat resistance, and a method for manufacturing the laminate.

[0008] In other words, a laminate according to one embodiment comprises at least a first substrate layer, an anchor coat layer, an adhesive layer, a second substrate layer, and a sealant layer arranged sequentially from the outer surface to the inner surface, wherein the first substrate layer has an electrostatic ink layer on the inner surface side, the adhesive layer is an extruded polyolefin resin layer, the first substrate layer is a substrate film layer, the second substrate layer is a paper substrate layer, and the sealant layer is a thermoplastic resin layer.

[0009] Furthermore, a method for manufacturing a laminate according to one embodiment comprises at least a first base material layer, an anchor coat layer, an adhesive layer, a second base material layer, and a sealant layer arranged sequentially from the outer surface to the inner surface, wherein the first base material layer is a base material film layer, the adhesive layer is a polyolefin resin layer, the second base material layer is a paper base material layer, and the sealant layer is a thermoplastic resin layer, and includes the steps of: printing the electrostatic ink layer on one side of the first base material layer to obtain a printed surface; applying the anchor coat agent onto the printed surface of the first base material layer to form an anchor coat layer; facing the coated surface of the anchor coat layer of the first base material layer and the second base material layer, and bonding the coated surface of the anchor coat layer of the first base material layer and one side of the second base material layer while extruding the molten polyolefin resin, which is the adhesive layer, between the anchor coat layer and the second base material layer; and laminating the sealant layer on the other side of the second base material layer. [Effects of the Invention]

[0010] According to the present disclosure, there is provided a laminate having a paper base material excellent in ink adhesion of a portion printed by a digital printing machine and excellent in heat resistance, and a method for manufacturing the laminate.

Brief Description of Drawings

[0011] [Figure 1] It is a cross-sectional view showing an example of a laminate according to an embodiment. [Figure 2] It is a plan view showing an example of a packaging bag according to an embodiment.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, an embodiment will be described with reference to the drawings. FIGS. 1 to 2 are diagrams showing an embodiment. Each of the drawings shown below is schematically shown. Also, numerical values such as dimensions of each member described in this specification and material names are examples as an embodiment, and are not limited thereto, and can be appropriately selected and used.

[0013] Also, with respect to terms used in this specification such as shape and geometric conditions, for example, terms such as "parallel", "orthogonal", "identical", etc., and values of length and angle, etc., they are not bound by a strict meaning, and are interpreted to include a range where similar functions can be expected.

[0014] The laminate 10 will be described.

[0015] The laminate 10 having an electrostatic ink layer by the digital printing machine of the present disclosure is a laminate aimed at improving ink adhesion of a portion printed by a digital printing machine and improving water resistance and heat resistance.

[0016] As shown in FIG. 1, the laminate 10 has an outer surface 19 and an inner surface 29. The inner surface 29 is the surface located on the side in contact with the packaged product, and the outer surface 19 is the surface located on the opposite side of the inner surface 29. The laminate 10 includes a first base material layer 11 located on the outer surface 19 side, an anchor coat layer 13, an adhesive layer 14, a second base material layer 15, an adhesive layer 16, a gas barrier layer 17, and a sealant layer 18. Further, an electrostatic ink layer 12 is provided on the inner surface side of the first base material layer 11. The adhesive layer 14 is an extruded polyolefin resin layer disposed on the surface of the anchor coat layer 13. In the present application, not only the surfaces of the laminate 10 but also the surfaces of each layer are referred to as the inner surface 29 for the surface located on the side of the accommodating portion 23 of the packaging bag 20, and the surface located on the opposite side of the inner surface is referred to as the outer surface 19.

[0017] Next, each layer constituting the laminate 10 will be described.

[0018] When the first base material layer 11 serves as the layer constituting the outer surface 19 of the packaging bag 20, a synthetic resin film having excellent properties in terms of mechanical, physical, chemical, etc. can be used. Further, when the first base material layer 11 is a transparent base material film, the printing layer (electrostatic ink layer 12) such as a pattern inside can be clearly shown. For example, as the first base material layer 11, polyester-based such as polyethylene terephthalate (PET), polyamide-based such as nylon (Ny), polypropylene-based, polycarbonate-based, and polyacetal-based resins can be used. In the present embodiment, as the first base material layer 11 having particularly excellent heat resistance and water resistance, polypropylene-based resins and polyester-based resins such as polyethylene terephthalate can be preferably used. Further, the first base material layer 11 is preferably a stretched film stretched in the uniaxial direction or the biaxial direction. The thickness of the first base material layer 11 can be 8 μm or more and 50 μm or less, and is preferably 9 μm or more and 25 μm.

[0019] An electrostatic ink layer 12 is formed on the inner surface of the first substrate layer 11. The electrostatic ink composition constituting the electrostatic ink layer is an ink composition used in liquid electrophotographic printing, i.e., electrostatic printing, and is printed on substrates such as paper and plastic. The electrostatic ink layer 12 may contain a coloring agent or pigment such as a dye, and a resin. In addition to these, it may also contain a carrier fluid or carrier liquid. Furthermore, it may contain a charge director, a charge adjuvant, a surfactant, a viscosity modifier, an emulsifier, and other additives.

[0020] Examples of colorants include cyan pigment, magenta pigment, yellow pigment, and black pigment. Examples of resins include thermoplastic resins such as ethylene acrylic acid copolymer, propylene acrylic acid copolymer, ethylene methacrylic acid copolymer, propylene methacrylic acid copolymer, and ethylene vinyl acetate copolymer.

[0021] Examples of carrier liquids include hydrocarbons, silicone oils, and vegetable oils. Examples of hydrocarbons include aliphatic hydrocarbons, branched-chain aliphatic hydrocarbons, and aromatic carbonized water. The electrostatic ink layer 12 may be substantially free of carrier liquid when printed on the substrate film layer 11. For example, the carrier liquid may be removed by an electrophoretic process during printing or by evaporation. This transfers substantially only solid components to the first substrate layer 11.

[0022] The charge director has the function of maintaining a sufficient electrostatic charge on the particles contained in the electrostatic ink layer 12. Examples of charge directors include ionic compounds such as metal salts of fatty acids, metal salts of sulfosuccinates, metal salts of oxyphosphates, metal salts of alkylbenzenesulfonic acids, and metal salts of aromatic carboxylic acids or aromatic sulfonic acids, as well as dual ionic and nonionic compounds such as polyoxyethylene-derived alkylamines, lecithin, polyvinylpyrrolidone, and organic acid esters of polyhydric alcohols.

[0023] The charge adjuvant has the effect of increasing or stabilizing the charge of particles contained in the electrostatic ink layer 12. Examples of charge adjuvants include barium petrolate, calcium petrolate, cosine naphthenate, calcium naphthenate, copper naphthenate, manganese naphthenate, nickel naphthenate, zinc naphthenate, iron naphthenate, barium stearate, cosine stearate, pearl stearate, zinc stearate, aluminum stearate, copper stearate, iron stearate, and metal carboxylates.

[0024] Furthermore, ink adhesion can be improved by performing surface treatments such as primer treatment or corona treatment on the first substrate layer 11 before printing.

[0025] Examples of primer layer materials include non-curing or curing primer coating agents such as chlorinated polypropylene, ethyl vinyl acetate, styrene maleic acid, isocyanate, polyolefin, organic titanate, polyethyleneimine, polybutadiene, polyester, and acrylic.

[0026] The above-mentioned primer layer can be formed by coating using methods such as roll coating, gravure coating, knife coating, dip coating, spray coating, or other coating methods, drying the coating film to remove solvents and diluents, and then performing aging treatment as necessary.

[0027] The anchor coat layer 13 is provided on the surface of the electrostatic ink layer 12 formed on the first substrate layer 11, and can improve the adhesion performance between the first substrate layer 11 and the adhesive layer 14.

[0028] Examples of anchor coat materials that constitute the anchor coat layer 13, which achieves the above effects, include chlorinated polypropylene, ethyl vinyl acetate, styrene maleic acid, isocyanate, polyolefin, organic titanate, polyethyleneimine, polybutadiene, polyester, and acrylic. Among these, an aqueous resin is preferred for the anchor coat layer 13, as it has good adhesion to the electrostatic ink layer 12 and can adsorb moisture from the paper substrate layer during the heat sealing process. Among aqueous resin anchor coat agents 13, polyethyleneimine is more preferred.

[0029] The anchor coat layer 13 is formed by applying a coating liquid to the printed surface of the first substrate layer 11. Conventional methods such as the commonly used casting method, dipping method, roll coating method, lavia coating method, screen printing method, reverse coating method, spray coating method, kit coating method, die coating method, metering bar coating method, chamber doctor combined coating method, and curtain coating method can be used. The anchor coat layer 13 is formed by heating and drying the coating film formed by the application of the coating liquid. The thickness of the anchor coat layer 13 is, for example, about 0.01 μm to 2 μm.

[0030] The adhesive layer 14 is used to laminate the electrostatic ink layer 12 surface of the first substrate layer 11 with the second substrate layer 15. In particular, if the adhesive layer 14 is an extruded polyolefin resin layer, it can protect the electrostatic ink layer 12 when subjected to impact or abrasion during the lamination process. The adhesive layer 14 can preferably be a polyolefin resin layer such as polyethylene, polypropylene, linear low-density polyethylene, ethylene-vinyl alcohol, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer, ionomer, or maleic anhydride-modified polyolefin resin.

[0031] In this embodiment, the thickness of the adhesive layer 14 is preferably 3 μm or more and 60 μm or less.

[0032] The second base material layer 15 can be a paper base material layer. The paper base material layer can be various types of paper, such as single-sided glossy paper, high-sizing bleached paper, high-sizing unbleached paper, pure white roll paper, kraft paper, cardboard, and processed paper. In the case of single-sided glossy paper, one side is a highly glossy surface, while the side opposite the glossy surface (the unbleached side) has a lower density than the glossy side.

[0033] There are no restrictions on the weighing of the paper substrate layer used in this embodiment, but the basis weight is 20 g / m². 2 More than 100g / m 2 The following range is preferable. Within this range, the bag offers excellent strength, processability, and ease of packaging the contents after the bag is made.

[0034] The gas barrier layer 17 is provided to extend the shelf life of the contents, and can be made of metal foils such as aluminum, zinc, gold, silver, and their alloys, ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride resin (PVDC), or aromatic polyamides such as nylon MXD6, or other gas barrier resin layers. In particular, when metal foil such as aluminum foil is used as the gas barrier layer, the barrier layer may also serve as a light-shielding layer.

[0035] The thickness of the gas barrier layer 17 is preferably 4 μm or more and 12 μm or less, and more preferably 5 μm or more and 9 μm or less.

[0036] Furthermore, a vapor-deposited film of an inorganic substance or inorganic oxide may be provided on any layer to serve as a barrier layer. Examples of materials for forming the vapor-deposited film include inorganic substances or inorganic oxides such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), and yttrium (Y).

[0037] Inorganic oxides are written as, for example, SiO X AlO XMOX is expressed as shown above (where M represents an inorganic element, and the value of X varies depending on the inorganic element). The range of X values ​​is as follows: silicon (Si) 0-2, aluminum (Al) 0-1.5, magnesium (Mg) 0-1, calcium (Ca) 0-1, potassium (K) 0-0.5, tin (Sn) 0-2, sodium (Na) 0-0.5, boron (B) 0-1.5, titanium (Ti) 0-2, lead (Pb) 0-1, zirconium (Zr) 0-2, and yttrium (Y) 0-1.5. In the above, when X=0, it is a complete inorganic element (pure substance), which is not transparent, and the upper limit of the range of X is the value when it is completely oxidized. For packaging materials, silicon (Si) and aluminum (Al) are preferably used, with silicon (Si) having a value in the range of 1.0 to 2.0 and aluminum (Al) having a value in the range of 0.5 to 1.5.

[0038] The thickness of the inorganic or inorganic oxide deposited film described above can be arbitrarily selected within the range of 100 nm to 1000 nm in order to obtain sufficient barrier properties.

[0039] The sealant layer 18 can be any thermoplastic resin that can melt and fuse with each other by heat. For example, one or more resins can be used, such as low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), polypropylene (PP), ethylene-vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, methylpentene polymer, polyethylene, or polyolefin resins modified with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, etc., polyvinyl acetate resin, polyester resin, polystyrene resin, and other resins.

[0040] In this embodiment, the sealant layer 18 is prepared by mainly comprising one or more of the above-mentioned resins, and optionally adding desired additives thereto to prepare a resin composition. Then, using the resin composition prepared above, a film or sheet can be formed using, for example, the T-die method, the inflation method, or other molding methods.

[0041] Furthermore, the sealant layer 18 may be made by adding, for example, an antiblocking agent, a lubricant (such as a fatty acid amide), an antistatic agent, a flame retardant, an inorganic or organic filler, etc., as optional additives.

[0042] In this embodiment, the thickness of the sealant layer 18 is preferably 10 μm or more and 100 μm or less, and more preferably 20 μm or more and 50 μm or less.

[0043] Furthermore, the lamination method for the second substrate layer 15, gas barrier layer 17, sealant layer 18, etc., can be, for example, wet lamination, dry lamination, solvent-free dry lamination, extrusion lamination, T-die co-extrusion molding, co-extrusion lamination, inflation method, or any other arbitrary method. In addition, if necessary, pretreatment such as corona treatment or ozone treatment can be applied when performing the lamination described above.

[0044] The contents may include, for example, food, pharmaceuticals, and seeds. However, the contents are not limited to these.

[0045] Next, an example of a method for manufacturing the laminate 10 will be described.

[0046] First, the first substrate layer 11 described above is prepared. Next, an electrostatic ink layer 12 is formed on the inner surface of the first substrate layer 11 by digital printing. If necessary, an anchor coat layer 13 is applied to the printed surface of the first substrate layer 11. Next, the coated surface of the anchor coat layer 13 and the second substrate layer 15 are placed facing each other, and the coated surface of the anchor coat layer 13 of the first substrate layer 11 and one surface of the second substrate layer 15 are bonded together by extruding the molten polyolefin resin, which is the adhesive layer 14. Next, if necessary, a gas barrier layer 17 is bonded to the other surface of the second substrate layer 15 via an adhesive layer 16, and then a sealant layer 18 is laminated and bonded together. In this way, a laminate 10 can be obtained comprising the first substrate layer 11, the electrostatic ink layer 12, the anchor coat layer 13, the adhesive layer 14, the second substrate layer 15, the adhesive layer 16, the gas barrier layer 17, and the sealant layer 18 in order from the outer surface 19 to the inner surface 29.

[0047] The packaging bag 20 is formed by heat sealing or the like on the laminated body 10. The sealing portion includes a side sealing portion 21 and a bottom sealing portion 22. The packaging bag 20 is configured to seal the packaging bag 20 by forming a containment portion 23 surrounded by the side sealing portion 21 and the bottom sealing portion 22. An opening means 24, such as a notch, can be provided in the side sealing portion 21.

[0048] This disclosure is not limited in any way to the embodiments described above. The packaging bag 20 can be manufactured in various forms by, for example, using the laminate 10 described above and folding it in half or in thirds, or by preparing two laminates 10, overlapping them with the sealant layer 18 surface of the front laminate 10 facing the sealant layer 18 surface of the back laminate 10, and then heat-sealing the peripheral edges in various heat-sealing forms such as side seal type, two-sided seal type, three-sided seal type, four-sided seal type, envelope seal type, gusset seal type (pillow seal type), pleated seal type, flat bottom seal type, or square bottom seal type. [Examples]

[0049] Next, specific examples of the above embodiment will be described.

[0050] (Example 1) First, a polyethylene terephthalate film (PET film, 12 μm thick) was prepared as the first substrate layer 11. Corona discharge treatment was applied to one side of this PET film to create a corona discharge treated surface. Next, a 0.2 μm thick primer layer was laminated onto this corona discharge treated surface using an acrylic resin (Michaelman Corporation, product name "DigiPrime050®") by roll coating. Then, digital printing was performed using a digital printing press (Hewlett-Packard, Indigo 20000 digital printing press for labels and packaging) to form an electrostatic ink layer 12. As the electrostatic ink composition, an electrostatic ink composition containing a thermoplastic resin containing a copolymer of ethylene acrylic acid and ethylene methacrylic acid (HP Indigo Electroink) was used. The colors used for the electrostatic ink layer 12 were white (W), yellow (Y), magenta (M), cyan (C), and black (K).

[0051] An anchor coat layer 13 was formed on the printed surface on which the electrostatic ink layer 12 was formed by applying an aqueous primer resin (a resin containing polyethyleneimine, manufactured by Dainippon Ink and Chemicals, Inc., product name: ACQ) as an anchor coat agent. The amount of aqueous polyethyleneimine applied was 0.10 g / m². 2 I applied a gravure coating to achieve this result.

[0052] A molten polyethylene resin (15 μm thick), which is the adhesive layer 14, was laminated onto the coated surface on which the anchor coat layer 13 was formed, using an extrusion laminating device. At this time, the extrusion temperature (processing temperature) of the molten polyethylene resin was set to 280°C.

[0053] The second base material layer 15 is manufactured by Hokuetsu Corporation, product name: Kishu High-Quality Paper N (basis weight 52.3 g / m²). 2A paper base material was prepared. Using the above extrusion laminating apparatus, the adhesive layer 14 (extruded polyethylene resin layer) and the second base material layer 15 (paper base material layer) were brought into contact, and the coating surface side of the anchor coat layer 13 of the first base material layer 11 was bonded to the adhesive layer 14 to obtain a laminate (intermediate).

[0054] As the gas barrier layer 17, an aluminum foil (manufactured by Toyo Aluminum Co., Ltd., thickness 7 μm) was prepared. Using the above extrusion laminating apparatus, the adhesive layer 16 (extruded polyethylene resin layer) and the gas barrier layer 17 (aluminum foil) were brought into contact, and the second base material layer 15 side of the intermediate was bonded to the adhesive layer 16 and laminated.

[0055] Using the extrusion laminating apparatus, a molten ethylene-methacrylic acid copolymer (thickness 20 μm) as the sealant layer 18 was laminated on the surface where the gas barrier layer 17 (aluminum foil) was formed to obtain a laminate 10. At this time, the extrusion temperature (processing temperature) of the molten ethylene-methacrylic acid copolymer was 280°C. The layer structure is as follows.

[0056] First base material layer 11 PET film (12 μm) / primer layer (3 μm) / electrostatic ink layer 12 (0.10 g / m 2 ) / anchor coat layer 13 aqueous polyethylene imine (0.10 g / m 2 ) / adhesive layer 14 extruded polyethylene resin (thickness 15 μm) / second base material layer 15 paper base material (basis weight 52.3 g / m 2 ) / adhesive layer 16 extruded polyethylene resin (thickness 15 μm) / gas barrier layer 17 aluminum foil (7 μm) / sealant layer 18 ethylene-methacrylic acid copolymer (thickness 20 μm)

[0057] (Example 2) As the second base material layer 15, a paper base material manufactured by Hokuriku Corporation, trade name: Kishu Premium Paper N (basis weight 64 g / m 2 ) was prepared, and a laminate was obtained in the same manner as in Example 1. The layer structure of the laminate of Example 2 is as follows.

[0058] First base layer 11 PET film (12 μm) / Primer layer (3 μm) / Electrostatic ink layer 12 (0.10 g / m²) 2 ) / Anchor coat layer 13 Water-based polyethyleneimine (0.10 g / m 2 ) / Adhesive layer 14 Extruded polyethylene resin (thickness 15 μm) / Second base material layer 15 Paper base material (basis weight 64 g / m²) 2 ) / Adhesive layer 16 Extruded polyethylene resin (thickness 15 μm) / Gas barrier layer 17 Aluminum foil (7 μm) / Sealant layer 18 Ethylene-methacrylic acid copolymer (thickness 20 μm)

[0059] (Comparative Example 1) A laminate was obtained in the same manner as in Example 1, except that the second substrate layer 15 was laminated to the printed surface of the first substrate layer 11, on which the electrostatic ink layer 12 was formed, using a dry laminating device instead of an extrusion laminating device, via an adhesive. The adhesive used was a two-component curing adhesive (ether-based, trade name: Takelac A-969V, curing agent Takenate A-5, manufactured by Mitsui Chemicals, Inc.), and the amount of adhesive applied was 3.0 g / m2.

[0060] (Comparative Example 2) A laminate was obtained in the same manner as in Example 1, except that the second substrate layer 15 was laminated to the printed surface of the first substrate layer 11, which had an electrostatic ink layer 12 formed on it, using a dry laminating device instead of an extrusion laminating device, via an adhesive. The adhesive used was a two-component curing adhesive (ester-based, trade name: main component RU77T, curing agent H7, manufactured by Rock Paint Co., Ltd.), and the amount of adhesive applied was 4.0 g / m². 2 That's what I decided.

[0061] (Comparative Example 3) A laminate was obtained in the same manner as in Example 1, except that the second substrate layer 15 was laminated to the printed surface of the first substrate layer 11, on which the electrostatic ink layer 12 was formed, using a dry laminating apparatus instead of an extrusion laminating apparatus, via an adhesive. The adhesive used was a two-component curing adhesive (epoxy type, trade name: main component AD502, curing agent CAT50, manufactured by Mitsui Chemicals, Inc.), and the amount of adhesive applied was 4.0 g / m². 2 That's what I decided.

[0062] (Comparative Example 4) A laminate was obtained in the same manner as in Example 1, except that the second substrate layer 15 was laminated to the printed surface of the first substrate layer 11, on which the electrostatic ink layer 12 was formed, using a dry laminating device instead of an extrusion laminating device, via an adhesive. The adhesive used was a two-component curing adhesive (urethane-based, product name: main component A-3210, curing agent A-3075, manufactured by Mitsui Chemicals, Inc.), and the amount of adhesive applied was 0.1 g / m². 2 That's what I decided.

[0063] The layer configurations of the laminates in Comparative Examples 1 to 4 are as follows. First base layer 11 PET film (12 μm) / electrostatic ink layer 12 (0.10 g / m²) 2 ) / adhesive layer 14 (4.0g / m 2 ) / 2nd base layer 15 paper base material (basis weight 52.3g / m 2 ) / Adhesive layer 16 Extruded polyethylene resin (thickness 15 μm) / Gas barrier layer 17 Aluminum foil (7 μm) / Sealant layer 18 Ethylene-methacrylic acid copolymer (thickness 20 μm)

[0064] <Evaluation of ink adhesion> The printability of digital printing in the examples and comparative examples was evaluated as follows. Specifically, the outer surface 19 of the digitally printed laminate 10 is sealed with a heat seal bar via a silicone sheet (manufactured by Togawa Rubber, product name: Silicone Rubber Sheet) at a sealing pressure of 2 kg / cm². 2 The inner surfaces 29 were bonded together at a sealing temperature of 160°C and a sealing time of 0.5 seconds. Subsequently, the outer surface of the digitally printed laminate 10 was visually evaluated according to the following criteria. The results are shown in Table 1. 5: There was absolutely no ink clumping or peeling. 4: Slight ink clumping and peeling occurred. 3. Ink aggregation and peeling occurred in approximately 50% of cases. 2: Ink aggregation and peeling occurred in approximately 80% of cases. 1: Ink aggregation and peeling occurred in approximately 100% of cases.

[0065] [Table 1]

[0066] As shown in Table 1, the laminates 10 of Examples 1 and 2 exhibited excellent ink adhesion without ink lifting due to the heat sealing bar. In contrast, when heat and pressure were simultaneously applied to the laminates of Comparative Examples 1-4 using a heat sealing bar, the moisture in the paper substrate evaporated, and the moisture did not transfer to the aluminum foil side. Instead, the moisture transferred to the printed surface side, causing ink aggregation and peeling, and ink bleeding was observed. [Explanation of Symbols]

[0067] 10 Laminate 11 First base layer 12 Electrostatic Ink Layer 13 Anchor Coat Layer 14 Adhesive layer 15 Second base layer 16 Adhesive layer 17. Gas barrier layer 18. Sealant layer 19 Exterior 20 packaging bags 21 Side sealing portion 22 Bottom seal section 23 Storage Unit 24 Opening method 29 Inner self

Claims

1. It comprises at least a first base layer arranged sequentially from the outer surface to the inner surface, an anchor coat layer, an adhesive layer, a second base layer, and a sealant layer, The first substrate layer has an electrostatic ink layer on its inner surface side, The adhesive layer is an extruded polyolefin resin layer. The aforementioned first substrate layer is a substrate film layer, The aforementioned second substrate layer is a paper substrate layer, The sealant layer is a laminate, which is a thermoplastic resin layer.

2. The laminate according to claim 1, further comprising a gas barrier layer between the second substrate layer and the sealant layer.

3. A method for manufacturing a laminate comprising at least a first substrate layer arranged sequentially from the outer surface to the inner surface, an anchor coat layer, an adhesive layer, a second substrate layer, and a sealant layer, wherein the first substrate layer has an electrostatic ink layer on its inner surface side, The aforementioned first substrate layer is a substrate film layer, The adhesive layer is a polyolefin resin layer. The aforementioned second substrate layer is a paper substrate layer, The sealant layer is a thermoplastic resin layer, A step of printing the electrostatic ink layer on one side of the first substrate layer to obtain a printed surface, A step of applying an anchor coating agent to the printed surface of the first substrate layer to form the anchor coating layer, The process involves placing the coated surface of the anchor coat layer of the first substrate layer and the second substrate layer opposite each other, and bonding the coated surface of the anchor coat layer of the first substrate layer and one side of the second substrate layer while extruding the molten polyolefin resin, which is the adhesive layer, between the anchor coat layer and the second substrate layer. A method for manufacturing a laminate, comprising the step of laminating the sealant layer on the other side of the second substrate layer.

Images