Method for manufacturing a laminate

Abstract

To provide a method for manufacturing a laminate which is excellent in economical efficiency and environmental load reduction, and has no poor appearance such as orange peel.SOLUTION: A method for manufacturing a laminate having at least a base material 1, an adhesive layer formed of a reactive adhesive containing a polyol main agent and a polyisocyanate curing agent, and a sealant base material 2 in this order, the sealant base material 2 opposed to each other being heat sealed includes: a step 1 of coating the reactive adhesive onto the base material 1 and / or the sealant base material 2 so as to satisfy CW1<CW2 when a coating amount of the reactive adhesive in a non seal part that is not heat sealed is represented by CW1 (g / m2:in terms of solid content), and a coating amount of the reactive adhesive of a seal part to be heat sealed is represented by CW2 (g / m2:in terms of solid content); and a step 2 of laminating the base material 1 and the sealant base material 2 through an adhesive layer formed of the reactive adhesive.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a laminate suitably used for packaging materials for foods, pharmaceuticals, cosmetics, detergents, sundries, and the like.

Background Art

[0002] As packaging materials for foods, clothing, cosmetics, sundries, etc., laminates obtained by multilaminating various plastic films are widely used. Such a laminate is generally manufactured by forming a printing layer on a plastic film to produce a printed film, and then laminating the obtained printed film and another plastic film using an adhesive. Further, a packaging material is manufactured by heat-sealing multilayer plastic films to each other by thermocompression bonding. The above printing layer is formed by a method such as on-demand printing such as inkjet printing in addition to gravure printing and flexographic printing of printing ink. Further, as the laminate adhesive, a two-component reactive adhesive composed of a polyol component and a polyisocyanate component is the mainstream, and a urethane adhesive layer is formed. As a method of laminating, it is general to apply an adhesive with a uniform coating amount over the entire surface by a gravure coater or a roll coater, and then bond the base material film on the bonding side by thermocompression bonding. In the above situation, for example, Patent Document 1 discloses a technique of using a two-component curable solventless adhesive having high reactivity but a short pot life by separately applying a polyol component and a polyisocyanate component onto a printing layer using an inkjet method.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the method described in Patent Document 1 applies a solventless adhesive regardless of the design of the packaging material, and the adhesive is applied to the unsealed portion that is not heat-sealed and does not require heat resistance in the same manner as the sealed portion that is heat-sealed. Therefore, the coating amount of the adhesive is uniform over the entire surface of the base material, and the same amount is applied to the sealed portion that is heat-sealed and the unsealed portion that is not heat-sealed. However, since high heat resistance is required for the sealed portion that is heat-sealed, in order to impart heat resistance to the sealed portion, a laminate adhesive in an amount exceeding the amount necessary to exhibit adhesive strength is applied to the entire surface of the base material including the unsealed portion. Therefore, improvement is desired from the viewpoints of economy and environmental load. And generally, since solventless adhesives are designed to have a low viscosity in order to impart coating suitability, there is a problem that when the coating amount is large, appearance defects such as a slippery texture are likely to occur. Therefore, an object of the present invention is to provide a method for manufacturing a laminate that is excellent in economy and reduction of environmental load and has no appearance defects such as a slippery texture.

Means for Solving the Problems

[0005] As a result of intensive studies to solve the above problems, it has been found that the above problems can be solved by the following embodiments, and the present invention has been completed.

[0006] An embodiment of the present invention has, in this order, at least a base material 1, an adhesive layer formed from a reactive adhesive containing a polyol main agent and a polyisocyanate curing agent, and a sealant base material 2, and is a method for manufacturing a laminate used by heat-sealing the sealant base materials 2 facing each other. The coating amount of the reactive adhesive in the unsealed portion that is not heat-sealed is CW1 (g / m 2 : in terms of solid content), and the coating amount of the reactive adhesive in the sealed portion that is heat-sealed is CW2 (g / m 2: When converted to solid content), the step 1 of applying the reactive adhesive onto the base material 1 and / or the sealant base material 2 so that CW1 < CW2 is satisfied, and the step 2 of laminating the base material 1 and the sealant base material 2 via an adhesive layer formed from the reactive adhesive. It relates to a method for manufacturing a laminate having

[0007] Another embodiment of the present invention relates to a method for manufacturing the above laminate, wherein the reactive adhesive is applied by a coating method including at least one selected from the group consisting of an inkjet coating method and a spray coating method.

[0008] Another embodiment of the present invention relates to the above method for manufacturing a laminate, wherein the step 1 includes a step a1 of applying the reactive adhesive to the entire surface of the base material 1 and / or the sealant base material 2, and a step a2 of applying the reactive adhesive to a heat-sealed portion to be heat-sealed on the base material 1 and / or the sealant base material 2.

[0009] Another embodiment of the present invention relates to the above method for manufacturing a laminate, wherein the step a1 is performed by a gravure coating method or a spray coating method, and the step a2 is performed by an inkjet coating method.

[0010] Another embodiment of the present invention relates to the above method for manufacturing a laminate, wherein the step 1 includes a step b1 of applying the reactive adhesive to a heat-sealed portion and an unsealed portion not to be heat-sealed of the base material 1 and / or the sealant base material 2 using an inkjet coating method.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide a method for manufacturing a laminate that is excellent in economy and reduction of environmental load and has no appearance defects such as yuzu skin.

Modes for Carrying Out the Invention

[0012] <Method for Manufacturing a Laminate> The present invention has, in this order, at least a base material 1, an adhesive layer formed from a reactive adhesive containing a polyol main agent and a polyisocyanate curing agent, and a sealant base material 2, and is a method for manufacturing a laminate used by heat-sealing with the sealant base materials 2 facing each other. In the method, the coating amount of the reactive adhesive in the unsealed portion that is not heat-sealed is CW1 (g / m 2 : in terms of solid content), and the coating amount of the reactive adhesive in the sealed portion that is heat-sealed is CW2 (g / m 2 : in terms of solid content). The method includes a step 1 of applying a reactive adhesive onto the base material 1 and / or the sealant base material 2 so that CW1 < CW2 is satisfied, and a step 2 of laminating the base material 1 and the sealant base material 2 via an adhesive layer formed from the reactive adhesive. By satisfying the above conditions for the coating amounts of the sealed portion that is heat-sealed and the unsealed portion that is not heat-sealed, it is possible to obtain a laminate that is excellent in economy and reduction of environmental load without applying an excessive amount of adhesive to the unsealed portion that is not heat-sealed and has no appearance defects such as fish-scale skin. The present invention will be described in detail below.

[0013] <Step 1> In step 1, the method of applying the reactive adhesive is not particularly limited and can be appropriately selected from known coating methods. Examples of such coating methods include a gravure coating method, a flexo coating method, a roll coater coating method, an inkjet coating method, and a spray coating method. The coating method may be used alone or in combination of two or more methods. In the present invention, the application amount of the reactive adhesive is different between the heat-sealed part and the unsealed part that is not heat-sealed. For example, when using the gravure coating method, by using a gravure cylinder plate according to the design of the packaging material, the application amounts of the heat-sealed part and the unsealed part that is not heat-sealed can be adjusted. Also, when using the inkjet coating method, the application amount of the adhesive can be adjusted on demand according to the design of the packaging material. In addition, the method of changing the application amount is not limited to the above, and a known method such as a method of performing multiple coatings while changing the coating range may be appropriately selected. Among them, the inkjet coating method is preferable because it is economically excellent.

[0014] In Step 1, the reactive adhesive is applied onto the base material 1 and / or the sealant base material 2. That is, the reactive adhesive may be applied to the base material 1, may be applied to the base material 2, or may be applied to both the base material 1 and the base material 2. As an example of applying to both, for example, there is a method of applying the adhesive only to the heat-sealed part of the base material 1 using the inkjet coating method, while applying the adhesive to the entire surface of the sealant base material 2 by the gravure coating method. When the reactive adhesive is applied to both the base material 1 and the sealant base material 2, the application amounts CW1 and CW2 represent the total of the application amounts to both base materials.

[0015] A preferred embodiment of Step 1 includes Step a1 of applying the reactive adhesive to the entire surface of the base material and Step a2 of applying the reactive adhesive to the heat-sealed part. After uniformly applying the reactive adhesive to the entire surface in Step a1, by applying the reactive adhesive only to the heat-sealed part, the application amount can be controlled, and the application amount of the heat-sealed part can be made larger than the application amount of the unsealed part that is not heat-sealed. Step a1 is preferably performed by the gravure coating method or the spray coating method, and Step a2 is preferably performed by the inkjet coating method.

[0016] Another preferred embodiment of Project 1 includes Step b1 of applying the reactive adhesive to the heat-sealed seal portion and the unsealed portion that is not heat-sealed of the base material 1 and / or the sealant base material 2 using an inkjet coating method. By using the inkjet coating method, the coating amounts of the heat-sealed seal portion and the unsealed portion that is not heat-sealed can be easily controlled on demand, and the coating amount of the heat-sealed seal portion can be made larger than the coating amount of the unsealed portion that is not heat-sealed.

[0017] [Base material 1] The base material 1 used in the present invention is not particularly limited, and a film-like or sheet-like plastic base material generally used for packaging materials can be used. These may be laminated laminates. Examples of the plastic base material include films of thermoplastic resins and thermosetting resins, preferably films of thermoplastic resins. Examples of the thermoplastic resin include polyolefin resins, polyester resins, polyamide resins, polystyrene resins, vinyl chloride resins, vinyl acetate resins, AS resins, ABS resins, acrylic resins, acetal resins, polycarbonate resins, cellulose resins, and cellulose-based plastics.

[0018] More specifically, polyolefin resin films such as polyethylene (PE) and biaxially oriented polypropylene (OPP); polyester resin films such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polylactic acid (PLA); polystyrene resin films; polyamide resin films such as nylon 6 and poly-p-xylylene adipamide (MXD6 nylon); polycarbonate resin films; polyacrylonitrile resin films; polyimide resin films; cellophane films; multilayers (e.g., nylon 6 / MXD6 / nylon 6, nylon 6 / ethylene-vinyl alcohol copolymer / nylon 6) and mixtures thereof; etc. are used. Among them, those having mechanical strength and dimensional stability are preferred. The plastic substrate may contain additives such as antistatic agents and ultraviolet light absorbers as required, and may be provided with a vapor deposition layer such as silica or alumina.

[0019] When the substrate 1 is a laminate composed of a plurality of substrates, it is preferable that the substrates are laminated via an adhesive layer, and it may have a metal foil layer such as an aluminum foil layer. The method for forming the adhesive layer is not limited, and it can be formed by a known method using a known adhesive. The substrate 1 may have a printing layer. Examples of the method for forming the printing layer include a gravure printing method, a flexographic printing method, a screen printing method, an offset printing method, an offset gravure method, a liquid electrophotography method (LEP), and an inkjet (IJ) method. The printing ink used for forming the above printing layer is not particularly limited, and solvent-based ink, water-based ink, UV-curable ink, two-component curable ink, toner ink, etc. can be used. The thickness of the printing layer is not particularly limited, but generally, it is often adjusted in the range of 0.5 to 3 μm. The thickness of the printed portion can be appropriately changed according to the design. Further, the substrate 1 may have a coating layer such as an anchor coating or a primer coating in order to improve the adhesion of the above-described printing layer.

[0020] The thickness of the substrate 1 is preferably 5 μm or more and 200 μm or less, more preferably 10 μm or more and 100 μm or less, and still more preferably 10 μm or more and 50 μm or less. The surface of the substrate 1 may be subjected to corona treatment or low-temperature plasma treatment.

[0021] [Adhesive layer] The adhesive layer in the present invention is formed from a reactive adhesive containing a polyol main agent and a polyisocyanate curing agent, and on at least the substrate 1 and / or the sealant substrate 2, "the coating amount CW1 (g / m of the reactive adhesive in the unsealed portion that is not heat-sealed 2 : in terms of solid content) < the coating amount CW2 (g / m of the reactive adhesive in the sealed portion that is heat-sealed 2It can be formed by applying a reactive adhesive so as to satisfy “in terms of solid content conversion”. The application of the reactive adhesive may be continuously performed without winding the printed matter into a roll after forming a printing layer on the base material 1 or the sealant base material 2, or may be performed after winding the printed matter into a roll.

[0022] The application amount of the reactive adhesive preferably satisfies 0.5 < CW1 < CW2 < 5 (g / m 2 : in terms of solid content conversion), more preferably, further, 1.0 < CW1 < 4 (g / m 2 : in terms of solid content conversion), and 1.2 < CW2 < 5 (g / m 2 : in terms of solid content conversion). The application amount CW1 is preferably 1.0 to 2.5 g / m 2 and the application amount CW2 is preferably 1.5 to 3.5 g / m 2 and CW2 / CW1 is preferably in the range of 1.1 to 6.0. By making the application amount CW2 of the sealed portion to be heat-sealed more than the application amount CW1 of the unsealed portion not to be heat-sealed, the heat resistance when making a packaging material by thermocompression bonding by heat sealing is improved, and troubles such as delamination can be suppressed. Also, by making the application amount CW1 of the unsealed portion not to be heat-sealed less than CW2, the adhesive is not used excessively, the economy can be enhanced from the viewpoint of material cost, and the environmental load can be reduced.

[0023] The adhesive layer in the present invention may be formed from a reactive adhesive containing a polyol main agent and a polyisocyanate curing agent, and a mixture of the polyol main agent and the polyisocyanate curing agent may be applied, or the polyol main agent and the polyisocyanate curing agent may be applied separately. The method of applying a mixture of the polyol main agent and the polyisocyanate curing agent is preferably used, for example, in a gravure coating method, a flexo coating method, or a roll coater coating method. The method of applying the polyol main agent and the polyisocyanate curing agent separately is preferably used, for example, in a gravure coating method, an inkjet coating method, a spray coating method, etc.

[0024] The polyol component contained in the polyol main agent is not particularly limited. For example, it includes polyester polyol, polyester urethane polyol, polyether polyol, polyether urethane polyol, polycarbonate polyol, polycarbonate urethane polyol, polycaprolactone polyol, polycaprolactone polyurethane polyol, polyolefin polyol, and acrylic polyol. In addition, low molecular weight glycols such as ethylene glycol and propylene glycol, and vegetable oils containing hydroxyl groups such as castor oil can also be used. Among them, from the viewpoint of the adhesive strength of the laminate, polyester polyol, polyester urethane polyol, and polyether urethane polyol are preferable.

[0025] The polyisocyanate component contained in the polyisocyanate curing agent is not particularly limited. For example, aliphatic diisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanatemethyl caproate; alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatemethyl-3,5,5-trimethylcyclohexyl isocyanate, 4,4′-methylenebis(cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate, methyl 2,6-cyclohexane diisocyanate, 1,4-bis(isocyanatemethyl)cyclohexane, 1,3-bis(isocyanatemethyl)cyclohexane; aromatic diisocyanates such as m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4- or 2,6-tolylene diisocyanate or a mixture thereof, 4,4′-toluidine diisocyanate, dianisidine diisocyanate, 4,4′-diphenyl ether diisocyanate; aromatic aliphatic diisocyanates such as 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ω,ω′-diisocyanate-1,4-diethylbenzene, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene or a mixture thereof; polyisocyanate monomers such as organic triisocyanates like triphenylmethane-4,4′,4″-triisocyanate, 1,3,5-triisocyanate benzene, 2,4,6-triisocyanate toluene, and organic tetraisocyanates like 4,4′-diphenyldimethylmethane-2,2′-5,5′-tetraisocyanate;Examples of the polyisocyanate include dimers, trimers, biurets, allophanates, and polyisocyanates having a 2,4,6-oxadiazinetrione ring obtained from carbon dioxide and the above polyisocyanate monomer, which are derived from the above polyisocyanate monomer.;

[0026] In addition, examples of the polyisocyanate component include adducts obtained by adding various glycol components shown below to the above polyisocyanate monomer. Examples of the glycol component used for forming the adduct include low molecular weight polyols having a molecular weight of less than 200, such as ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolpropane, cyclohexanedimethanol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol, sorbitol, etc., polyesters having a molecular weight of 200 to 20,000, polyetheresters, polyesteramides, polycaprolactone polyols, polyvalerolactone polyols, acrylic polyols, polycarbonate polyols, polyhydroxyalkanes, castor oil, and polyurethane polyols.;

[0027] The mixing ratio (NCO / OH (molar ratio)) of the polyol main agent and the polyisocyanate curing agent is not particularly limited, but is generally preferably in the range of 1.1 to 10.; The NCO / OH ratio in the adhesive may be changed depending on the location, and the NCO / OH ratio in the adhesive of the heat-sealed part and the NCO / OH ratio in the adhesive of the unsealed part that is not heat-sealed may be the same or different.; The NCO / OH ratio in the adhesive of the unsealed portion that is not heat-sealed is preferably in the range of 1.1 to 3.0, and the NCO / OH ratio in the adhesive of the sealed portion that is heat-sealed is preferably in the range of 1.5 to 4.0. It is more preferable that the NCO / OH ratio in the adhesive of the sealed portion that is heat-sealed is greater than the NCO / OH ratio in the adhesive of the unsealed portion that is not heat-sealed. When adjusting the NCO / OH ratio, for example, when using an inkjet coating method, the discharge amount of each of the head for discharging the main agent and the head for discharging the curing agent may be adjusted, or the discharge amount may be adjusted by increasing or decreasing the number of heads.

[0028] The reactive adhesive may be a solventless adhesive, or a solvent-based adhesive or an aqueous adhesive containing an organic solvent or water. Preferably, it is a solvent-based adhesive or an aqueous adhesive containing an organic solvent or water. Further, the reactive adhesive may contain additives such as an antioxidant, an ultraviolet absorber, a fungicide, a plasticizer, and a lubricant, if necessary. When containing an organic solvent or water, after applying the reactive adhesive, if necessary, the adhesive layer can be formed by drying the organic solvent or water using drying equipment such as a drying oven.

[0029] <Step 2> A laminate can be obtained by laminating and bonding the base material 1 and the sealant base material 2 via a reactive adhesive layer. The method of bonding the base material 1 and the sealant base material 2 is not particularly limited and can be appropriately selected from known methods. A preferable example of such a method is a method using a hot nip roll.

[0030] [Base material 2] Examples of the base material 2 used in the present invention include, in addition to the base materials mentioned above for the base material 1, a sealant base material, and a laminate in which these are laminated may also be used. Examples of the sealant base material include polyethylene such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE), acid-modified polyethylene, unoriented polypropylene (CPP), acid-modified polypropylene, copolymerized polypropylene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylate copolymer, ethylene-(meth)acrylic acid copolymer, and ionomer. The base material 2 is preferably a sealant base material and contains a polyolefin. The base material 2 may contain additives such as an antistatic agent and an ultraviolet inhibitor as required, and may be provided with a vapor deposition layer of aluminum, silica, alumina, etc.

[0031] The thickness of the base material 2 is not particularly limited, and considering workability for processing into a packaging container, heat sealability, etc., it is preferably 10 μm or more and 150 μm or less, more preferably 20 μm or more and 70 μm or less. The base material 2 may be provided with unevenness having a height difference of about several μm to impart slipperiness and tear resistance of the packaging material. The surface of the base material 2 may be subjected to corona treatment or low-temperature plasma treatment. Also, a sealant layer may be provided on the outermost layer of the base material 2, and the sealant layer may be either a heat sealant layer or a cold sealant layer.

[0032] Thus, by using the present invention, according to the design of the packaging material (sealed part and unsealed part), the coating amount of the adhesive can be optimized, the economy can be improved from the viewpoint of material cost, and the environmental load can be reduced by eliminating excessive material use, which is useful in the field of packaging materials.

Examples

[0033] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In the Examples and Comparative Examples, "parts" and "%" mean "parts by mass" and "% by mass" unless otherwise specified.

[0034] <Preparation and production of reactive adhesive> (Reactive adhesive Ad1) 17 parts of solvent-based polyester polyol TM-569 (manufactured by Toyo Morton, solid content 62%), 0.8 parts of aliphatic isocyanate CAT-RT37 (manufactured by Toyo Morton, solid content 95%), and ethyl acetate were mixed to obtain a reactive adhesive Ad1 with a solid content of 30%.

[0035] (Main agent A1) The solvent-based polyester polyol TM-569 (manufactured by Toyo Morton, solid content 62%) was diluted with ethyl acetate to obtain a main agent A1 with a solid content of 20%.

[0036] (Main agent A2) 98 parts of Sannix PP-200 (manufactured by Sanyo Chemical Industries) and 2 parts of Sannix GP-250 (manufactured by Sanyo Chemical Industries) were mixed to obtain a main agent A2.

[0037] (Hardener B1) The aliphatic isocyanate CAT-RT37 (manufactured by Toyo Morton, solid content 95%) was diluted with ethyl acetate to obtain a hardener B1 with a solid content of 5%.

[0038] (Hardener B2) Polymeric MDI Millionate MR-100 (manufactured by Tosoh Corporation) was used as the hardener B2.

[0039] (Preparation of printing ink) (Water-based ink set P1) (Preparation of pigment dispersions 1C, 1M, 1Y, 1K) 20 parts of C.I. Pigment Blue 15:3, 20 parts of a varnish of a colorant dispersion resin (a water-soluble resin containing styrene, acrylic acid, and stearyl methacrylate as constituent units in a mass ratio of 25:40:35, having a weight average molecular weight of 25,000 and an acid value of 185 mgKOH / g, solid content 25%), and 60 parts of water were charged into a mixing container and then thoroughly mixed with a stirrer. Subsequently, dispersion was carried out using a Dyno Mill (bead mill manufactured by Shinmaru Enterprises Co., Ltd.) with a volume of 0.6 L filled with zirconia beads having a diameter of 0.5 mm to obtain a cyan pigment dispersion (designated as pigment dispersion 1C). In addition, except that the pigments were changed to C.I. Pigment Red 122, C.I. Pigment Yellow 14, and carbon black, respectively, magenta, yellow, and black pigment dispersions (hereinafter referred to as pigment dispersion liquid 1M, pigment dispersion liquid 1Y, and pigment dispersion liquid 1K, respectively) were obtained in the same manner as pigment dispersion liquid 1C.

[0040] 〔Preparation of Binder Resin 1〕 72.4 parts of 2-butanone was charged into a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, and replaced with nitrogen gas. After heating the inside of the reaction vessel to 80 °C, a mixture of 4.5 parts of methacrylic acid, 5.0 parts of 2-hydroxyethyl methacrylate, 90.5 parts of methyl methacrylate, and 12 parts of V-601 (a polymerization initiator manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 2 hours to carry out a polymerization reaction. After completion of the dropwise addition, the reaction was further carried out at 80 °C for 3 hours, then 0.6 part of V-601 was added, and the reaction was continued at 80 °C for 2 hours to obtain a solution of binder resin 1 which is a hydrosol. The weight average molecular weight of the above binder resin 1 measured using GPC (manufactured by Tosoh Corporation, HLC-8120GPC) equipped with a TSKgel column (manufactured by Tosoh Corporation) and an RI detector and using THF as the developing solvent was about 7,000. After cooling the solution of the above binder resin 1 to 50 °C, 4.7 parts of dimethylaminoethanol was added for neutralization, and then 140 parts of water was added. Thereafter, the inside of the reaction vessel was heated to 78 °C or higher, 2-butanone was distilled off by azeotroping with water, and then adjusted with water so that the solid content became 30% to obtain a varnish of binder resin 1. The acid value and hydroxyl value of binder resin 1 calculated from the structural units of the resin were 29.3 mgKOH / g and 21.6 mgKOH / g, respectively. Also, the glass transition temperature (Tg) measured using DSC (manufactured by PerkinElmer, DSC6000) was 103 °C.

[0041] 〔Preparation of Aqueous Ink Set P1〕 20 parts of pigment dispersion 1C, 21 parts of varnish of binder resin 1 (solid content 30%), 25 parts of 1,2-propanediol, 1 part of Surfynol 465 (an acetylene-based surfactant manufactured by Shin-Etsu Chemical Co., Ltd.), 0.1 part of Proxel GXL (a preservative manufactured by Lonza), and 32.9 parts of water were sequentially charged into a mixing container. Next, after heating the inside of the mixing container to 50°C, it was mixed with a stirrer for 1 hour. Then, filtration was performed using a depth-type filter with a pore size of 1 μm to remove coarse particles, thereby obtaining a cyan-colored aqueous ink (referred to as Ink 1C). Also, except that the pigment dispersions were changed to pigment dispersion 1M, pigment dispersion 1Y, and pigment dispersion 1K, respectively, magenta-colored, yellow-colored, and black-colored aqueous inks (referred to as Ink 1M, Ink 1Y, and Ink 1K, respectively) were obtained in the same manner as Ink 1C. The four-color inks of Ink 1C, Ink 1M, Ink 1Y, and Ink 1K thus prepared were used as the aqueous ink set P1.

[0042] <Manufacture of laminate> (Example 1) On polyethylene terephthalate (PET) with a thickness of 12 μm, a white ink of LP Bio (manufactured by Toyo Ink Co., Ltd.) was used by the gravure printing method to form a printing layer on the entire surface. The thickness of the printing layer was 1 μm. After forming the printing layer, continuously, a reactive adhesive Ad1 was applied on the printing layer by the gravure coating method, and the solvent was dried in a drying oven. Next, linear low-density polyethylene (LLDPE) with a thickness of 100 μm was pressure-bonded with a nip roll at 50°C and aged in an oven at 40°C for 4 days to cure the adhesive layer, obtaining a laminate having a structure of PET / printing layer / adhesive layer / LLDPE. The gravure cylinder used for applying the adhesive had different line number patterns formed in the heat-sealed seal part and the non-heat-sealed unsealed part. A pattern with a 110-line grid pattern in the seal part and a 180-line grid pattern in the unsealed part was used. The application amount of the reactive adhesive in the seal part was 3.5 g / m 2(Solid content conversion), the coating amount of the reactive adhesive in the unsealed part was 1.5 g / m 2 (Solid content conversion).

[0043] (Example 2) On polyethylene terephthalate (PET) with a thickness of 12 μm, LP Bio white ink (manufactured by Toyo Ink Co., Ltd.) was used by the gravure printing method to form a printing layer on the entire surface. The thickness of the printing layer was 1 μm. After forming the printing layer, continuously, the reactive adhesive Ad1 was applied on the printing layer by the gravure coating method, and the solvent was dried in a drying oven. After drying the solvent, continuously, the main agent A1 was ejected from the first inkjet head to the seal part to be heat-sealed by the inkjet coating method, and the curing agent B1 was ejected from the second inkjet head to the seal part to be heat-sealed, and the solvent was dried in a drying oven. Next, linear low-density polyethylene (LLDPE) with a thickness of 100 μm was pressure-bonded with a nip roll at 50 °C and aged in an oven at 40 °C for 4 days to cure the adhesive layer, and a laminate having a structure of PET / printing layer / adhesive layer / LLDPE was obtained. The gravure cylinder used for applying the adhesive was a 180-line grid type with a pattern formed on the entire surface. The inkjet head used was KJ4C-0360 (manufactured by Kyocera). The coating amount of the reactive adhesive in the seal part to be heat-sealed was 3.5 g / m 2 (Solid content conversion), and the coating amount of the reactive adhesive in the unsealed part not to be heat-sealed was 1.5 g / m 2 (Solid content conversion).

[0044] (Example 3) On polyethylene terephthalate (PET) with a thickness of 12 μm, LP Bio white ink (manufactured by Toyo Ink Co., Ltd.) was used by the gravure printing method to form a printing layer on the entire surface. The thickness of the printing layer was 1 μm. After forming the printing layer, successively, on the said printing layer, a reactive adhesive Ad1 was applied by a spray coating method, and after drying the solvent in a drying oven, by an inkjet coating method, from a first inkjet head, a main agent A1 was ejected onto a seal portion to be heat-sealed, and further, from a second inkjet head, a curing agent B1 was ejected onto the seal portion to be heat-sealed, and the solvent was dried in a drying oven. Next, linear low density polyethylene (LLDPE) with a thickness of 100 μm was pressure-bonded with a nip roll at 50 °C and aged in an oven at 40 °C for 4 days to cure the adhesive layer, and a laminate having a structure of PET / printing layer / adhesive layer / LLDPE was obtained. As the inkjet head, KJ4C-0360 (manufactured by Kyocera) was used. The coating amount of the reactive adhesive in the seal portion to be heat-sealed was 3.5 g / m 2 (in terms of solid content), and the coating amount of the reactive adhesive in the unsealed portion not to be heat-sealed was 1.5 g / m 2 (in terms of solid content).

[0045] (Example 4) On polyethylene terephthalate (PET) with a thickness of 12 μm, using LP Bio white ink (manufactured by Toyo Ink Co., Ltd.) by a gravure printing method, a printing layer was formed over the entire surface. The thickness of the printing layer was 1 μm. After forming the printing layer, successively, on the said printing layer, as an inkjet coating method, from a first inkjet head, a main agent A1, and further, from a second inkjet head, a curing agent B1 were ejected with different ejection amounts in the seal portion to be heat-sealed and the unsealed portion not to be heat-sealed, respectively, and the solvent was dried in a drying oven. Next, linear low density polyethylene (LLDPE) with a thickness of 100 μm was pressure-bonded with a nip roll at 50 °C and aged in an oven at 40 °C for 4 days to cure the adhesive layer, and a laminate having a structure of PET / printing layer / adhesive layer / LLDPE was obtained. As the inkjet head, KJ4C-0360 (manufactured by Kyocera) was used. The coating amount of the reactive adhesive in the seal portion to be heat-sealed was 3.5 g / m 2(Solid content conversion), the coating amount of the reactive adhesive when not heat-sealed was 1.5 g / m 2 (in terms of solid content).

[0046] (Examples 5 and 6) In Example 4, a laminate was obtained in the same manner as in Example 4, except that the coating amounts of the sealed portion and the unsealed portion were changed as shown in Table 1.

[0047] (Example 7) In Example 2, a laminate was obtained in the same manner as in Example 2, except that the printing method was changed to the flexographic printing method and the ink was changed to the white ink of Aqua Ecoal (manufactured by Toyo Ink Co., Ltd.). The residual moisture of Aqua Ecoal was 4.8 g / m 2 .

[0048] (Example 8) In Example 2, a laminate was obtained in the same manner as in Example 2, except that the printing method was changed to the inkjet printing method and the ink was changed to Ink Set P1. The residual moisture of the printing layer was 2.5 g / m 2 , and the residual 1,2-propanediol was 3.6 g / m 2 .

[0049] (Example 9) On polyethylene terephthalate (PET) with a thickness of 12 μm, a printing layer was formed on the entire surface using the gravure printing method with the white ink of LP Bio (manufactured by Toyo Ink Co., Ltd.). The thickness of the printing layer was 1 μm. Thereafter, the polyethylene terephthalate (PET) on which the printed layer was formed in a roll shape was unwound again, and the reactive adhesive Ad1 was applied on the above printed layer by the gravure coating method, and the solvent was dried in a drying oven. Next, linear low-density polyethylene (LLDPE) with a thickness of 100 μm was pressure-bonded with a nip roll at 50 °C and aged in an oven at 40 °C for 4 days to cure the adhesive layer, and a laminate having a structure of PET / printed layer / adhesive layer / LLDPE was obtained. The gravure cylinder used for applying the adhesive has different line number patterns formed on the heat-sealed part and the unsealed part that is not heat-sealed. A pattern with 110 lines in a grid pattern is formed on the sealed part, and a pattern with 180 lines in a grid pattern is formed on the unsealed part. The amount of the reactive adhesive applied to the sealed part was 3.5 g / m 2 (in terms of solid content), and the amount of the reactive adhesive applied to the unsealed part was 1.5 g / m 2 (in terms of solid content).

[0050] (Example 10) On polyethylene terephthalate (PET) with a thickness of 12 μm, using LP Bio white ink (manufactured by Toyo Ink Co., Ltd.) by the gravure printing method, a printing layer was formed over the entire surface. The thickness of the printing layer was 1 μm. After that, the polyethylene terephthalate with the formed printing layer wound in a roll was unwound again, and the reactive adhesive Ad1 was applied onto the above printing layer by the gravure coating method, and the solvent was dried in a drying oven. Next, as an inkjet coating method onto a linear low-density polyethylene (LLDPE) with a thickness of 100 μm, the main agent A1 was ejected from the first inkjet head and the curing agent B1 was ejected from the second inkjet head to the heat-sealed part respectively, and the solvent was dried in a drying oven. Next, the surface of the reactive adhesive Ad1 formed on the PET and the surface of the reactive adhesive composed of the main agent A1 and the curing agent B1 formed on the LLDPE were pressure-bonded with a nip roll at 50°C and aged in an oven at 40°C for 4 days to cure the adhesive layer, and a laminate having a structure of PET / printing layer / adhesive layer / LLDPE was obtained. The gravure cylinder used for applying the adhesive was one with a 180-line grid pattern formed over the entire surface. The inkjet head used was KJ4C-0360 (manufactured by Kyocera). The amount of the reactive adhesive (that is, the total of the reactive adhesive Ad1, the main agent A1, and the curing agent B1) applied to the sealed part was 3.5 g / m 2 (in terms of solid content), and the amount of the reactive adhesive applied to the unsealed part was 1.5 g / m 2 (in terms of solid content).

[0051] (Example 11) A laminate was obtained in the same manner as in Example 1, except that polyethylene terephthalate (PET) with a thickness of 12 μm was changed to MDO PE Film (manufactured by Windmiller) with a thickness of 12 μm.

[0052] (Example 12) On polyethylene terephthalate (PET) with a thickness of 12 μm, a reactive adhesive Ad1 was applied by a gravure coating method, and the solvent was dried in a drying oven. Next, linear low-density polyethylene (LLDPE) with a thickness of 100 μm was pressure-bonded with a nip roll at 50 °C and aged in an oven at 40 °C for 4 days to cure the adhesive layer, obtaining a laminate having a structure of PET / adhesive layer / LLDPE. The gravure cylinder used for applying the adhesive had different line patterns formed in the heat-sealed part and the unsealed part that was not heat-sealed. A pattern with 110 lines in the grid pattern was formed in the sealed part, and a pattern with 180 lines in the grid pattern was formed in the unsealed part. The application amount of the reactive adhesive in the sealed part was 3.5 g / m 2 (in terms of solid content), and the application amount of the reactive adhesive in the unsealed part was 1.5 g / m 2 (in terms of solid content).

[0053] (Comparative Example 1) On polyethylene terephthalate (PET) with a thickness of 12 μm, white ink of LP Bio (manufactured by Toyo Ink Co., Ltd.) was used by a gravure printing method to form a printing layer on the entire surface. The thickness of the printing layer was 1 μm. After forming the printing layer, continuously, a reactive adhesive Ad1 was applied on the printing layer by a gravure coating method, and the solvent was dried in a drying oven. Next, linear low-density polyethylene (LLDPE) with a thickness of 100 μm was pressure-bonded with a nip roll at 50 °C and aged in an oven at 40 °C for 4 days to cure the adhesive layer, obtaining a laminate having a structure of PET / printing layer / adhesive layer / LLDPE. The gravure cylinder used for applying the adhesive has different line patterns formed in the heat-sealed part and the non-heat-sealed part. A pattern with 180 lines in the grid pattern is formed in the sealed part, and a pattern with 110 lines in the grid pattern is formed in the non-sealed part. The amount of the reactive adhesive applied in the sealed part is 1.5 g / m 2 (in terms of solid content), and the amount of the reactive adhesive applied in the non-sealed part is 3.5 g / m 2 (in terms of solid content).

[0054] (Comparative Example 2) On polyethylene terephthalate (PET) with a thickness of 12 μm, a printing layer was formed on the entire surface by using gravure printing method with LP Bio white ink (manufactured by Toyo Ink Co., Ltd.). The thickness of the printing layer was 1 μm. After forming the printing layer, continuously, on the above printing layer, by using inkjet coating method, from the first inkjet head, the main agent A2 was discharged onto the entire surface, and from the second inkjet head, the curing agent B2 was discharged onto the entire surface. Next, linear low-density polyethylene (LLDPE) with a thickness of 100 μm was pressure-bonded with a nip roll at 50 °C and aged in an oven at 40 °C for 4 days to cure the adhesive layer, and a laminate having a structure of PET / printing layer / adhesive layer / LLDPE was obtained. The inkjet head used was KJ4C-0360 (manufactured by Kyocera). The amount of the reactive adhesive applied was 3.5 g / m 2 (in terms of solid content) for both the sealed part and the non-sealed part.

[0055] <Evaluation of the laminate> For the obtained laminate, the laminate appearance, the appearance after heat sealing, and the economy of the laminate were evaluated. The results are shown in Table 1.

[0056] [Laminate appearance] The laminate appearance was visually confirmed and evaluated according to the following criteria. A: No scratches, defects, unevenness, and good appearance (good) B: Appearance defects such as scratches, defects, and unevenness are observed (not acceptable)

[0057] [Appearance after heat sealing] After the laminate was pressure-bonded to a heat-sealing bar at 150°C for 1 second, the appearance after immersion in warm water at 98°C for 60 minutes was visually confirmed and evaluated according to the following criteria. A: No abnormality (good) B: Delamination (peeling) occurred (not acceptable)

[0058] [Economy, reduction of environmental load] Those with a smaller coating amount in the unsealed part that is not heat-sealed than in the sealed part that is heat-sealed were rated as "good", and those with a coating amount in the unsealed part that is not heat-sealed equal to or more than that in the sealed part that is heat-sealed were rated as "bad".

[0059]

Table 1

[0060] The abbreviations in Table 1 are shown below. 12μm PET: Biaxially oriented polyester film "FE2001" manufactured by Futamura Chemical Co., Ltd., thickness 12μm 100μm LLDPE: Linear low-density polyethylene film "TUX-FC-D" manufactured by Mitsui Chemicals Toagosei Co., Ltd., thickness 100μm 12μm HDPE: Biaxially oriented high-density polyethylene film "MDO PE Film" manufactured by Windmiller Co., Ltd., thickness 12μm

[0061] According to the results in Table 1, the laminate produced by the manufacturing method of the present invention had a good laminate appearance and an excellent appearance after heat sealing. In addition, in these laminates, the adhesive coating amount in the unsealed part that was not heat-sealed was reduced compared to that in the sealed part that was heat-sealed, and they were excellent in terms of economy and reduction of environmental load. On the other hand, in Comparative Example 1, although the adhesive coating amount in the sealed part was reduced, since the area ratio of the unsealed part in the general package was large, the effects of economy and reduction of environmental load due to the reduction of the coating amount were insufficient. Furthermore, peeling occurred due to immersion in warm water after heat sealing. Comparative Example 2 corresponds to Patent Document 1. Since the adhesive application amounts of the sealed portion to be heat-sealed and the unsealed portion not to be heat-sealed are the same, it is inferior in terms of economy and reduction of environmental load. Furthermore, since the solvent-free adhesive has low cohesive strength, the appearance and adhesive strength have deteriorated.

Claims

1. A method for manufacturing a laminate having at least a base material 1, an adhesive layer formed from a reactive adhesive containing a polyol main agent and a polyisocyanate curing agent, and a sealant base material 2 in this order, and heat-sealing the sealant base materials 2 facing each other for use, The application amount of the reactive adhesive in the unsealed portion that is not heat-sealed is CW1 (g / m ２ : in terms of solid content), and the application amount of the reactive adhesive in the sealed portion that is heat-sealed is CW2 (g / m ２ : in terms of solid content). When CW1 < CW2 is satisfied, step 1 of applying the reactive adhesive onto the base material 1 and / or the sealant base material 2 is performed, a step 2 of laminating the base material 1 and the sealant base material 2 via an adhesive layer formed from the reactive adhesive, The manufacturing method of the laminate having (however, except the case where the adhesive layer is not laminated on the unsealed portion).

2. The method for manufacturing a laminate according to claim 1, wherein the reactive adhesive is applied by a coating method including at least one selected from the group consisting of an inkjet coating method and a spray coating method.

3. The method for manufacturing a laminate according to claim 1 or 2, wherein the step 1 includes a step a1 of applying the reactive adhesive to the entire surface of the base material 1 and / or the sealant base material 2, and a step a2 of applying the reactive adhesive to a seal portion to be heat-sealed on the base material 1 and / or the sealant base material 2.

4. The method for manufacturing a laminate according to claim 3, wherein the step a1 is performed by a gravure coating method or a spray coating method, and the step a2 is performed by an inkjet coating method.

5. The method for manufacturing a laminate according to claim 1 or 2, wherein the step 1 includes a step b1 of applying the reactive adhesive to a seal portion to be heat-sealed and an unsealed portion not to be heat-sealed of the base material 1 and / or the sealant base material 2 using an inkjet coating method.

Images