Method for manufacturing a film laminate

Abstract

The present invention addresses the problem of providing a method for producing a film laminate, the method being capable of producing, with high productivity, a film laminate that exhibits excellent ink curability and excellent adhesion to a second base material.　The present invention provides a method for producing a film laminate, wherein a printing step for applying an active energy ray-curable printing ink to a first base material film that is composed of at least a plastic film, an adhesive application step for applying an adhesive, and a lamination step for superposing a second base material are sequentially performed in this order in an in-line manner. This method for producing a film laminate additionally has a curing step for curing the active energy ray-curable printing ink by means of irradiation of an active energy ray at least after the adhesive application step.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a film laminate, which in-line performs a printing step of applying an active energy ray-curable printing ink, an adhesive application step of applying an adhesive, and a lamination step of laminating a second substrate in this order on a first substrate film made of at least a plastic film.

Background Art

[0002] Lithographic printing (offset printing) is a printing method that has been widely popularized as a system for supplying printed materials at high speed, in large quantities, and at low cost. Conventionally, the lithographic printing method has been mainly applied to printing on paper, but in recent years, its application to flexible packaging printing for printing on thin film plastic films has been studied, mainly for packaging applications such as daily necessities, food products, and pharmaceuticals.

[0003] In recent years, active energy ray-curable lithographic printing inks that instantaneously cure by irradiating active energy rays such as mercury lamps, metal halide lamps, light-emitting diodes, and electron beams have spread in many fields from the viewpoints of equipment, safety, environment, and high productivity. Such active energy ray-curable lithographic printing inks are considered to be suitable materials for printing on plastic films with poor heat resistance because they can be cured at room temperature in a short time. However, with an increase in printing speed and a reduction in exposure amount due to power saving, the ink may not be cured sufficiently. In contrast, as a lithographic printing ink having high sensitivity to active energy ray curability and water washability, and also excellent in resistance to ground staining during printing and water resistance of the cured film, a lithographic printing ink characterized by containing (a) a pigment and (b) a resin having an ethylenically unsaturated group and a hydrophilic group has been proposed (see, for example, Patent Document 1). And in the above-mentioned packaging applications and the like, from the viewpoints of protecting the contents, improving impact resistance, and imparting heat sealability, it is generally performed to bond another plastic film, metal foil, hot melt film (sealant), etc. to the obtained printed material.

[0004] On the other hand, as a method for manufacturing a packaging material using a thin film plastic film as a base material, there are methods such as printing a pattern on the base material, curing the ink by irradiating with energy rays, and then laminating with a heat seal layer via an adhesive (for example, see Patent Document 2), or applying an ink composition to a transparent base material 1, drying or curing to obtain an ink layer, applying a specific adhesive composition on the ink layer to form a precursor of an adhesive layer, laying a base material 2 on the precursor of the adhesive layer, and curing the precursor of the adhesive layer to form an adhesive layer (for example, see Patent Document 3), etc. have been proposed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the production of a laminated film in which another base material is laminated on a printed matter using a plastic film as a base material, Patent Documents 2 to 3 disclose a method of laminating a second base material offline using an isocyanate-curing type adhesive on a cured ink layer. In such a method, from the viewpoint of reducing organic solvents, an active energy ray-curing type printing ink is preferably used, but there are problems that the curability of the ink and the adhesion between the ink and the plastic film are insufficient. In addition, for the curing of the isocyanate-curing type adhesive, a long aging process such as 3 days at 40°C is required, and there are problems in productivity.

[0007] Therefore, the present invention aims to solve such problems of the prior art and provide a method for manufacturing a film laminate that can produce a film laminate excellent in curability of ink and adhesion to a second substrate with high productivity.

Means for Solving the Problems

[0008] The inventors focused on the fact that when the surface of the ink is exposed to oxygen in the process of curing the ink by active energy rays, the curability of the ink and the adhesion between the ink and the plastic film become insufficient, and thus arrived at the present invention.

[0009] That is, the present invention is a method for manufacturing a film laminate in which a printing step of applying an active energy ray-curable printing ink, an adhesive application step of applying an adhesive, and a lamination step of laminating a second substrate are performed in-line in this order on a first substrate film made of at least a plastic film, and further includes a curing step of irradiating active energy rays to cure the active energy ray-curable printing ink at least after the adhesive application step. wherein the adhesive in the adhesive application step is a solvent-free isocyanate-curing adhesive, and the curing step is provided before the laminating step, It is a method for manufacturing a film laminate.

Advantages of the Invention

[0010] According to the method for manufacturing a film laminate of the present invention, a film laminate excellent in curability of ink and adhesion to a second substrate can be produced with high productivity.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0012] Hereinafter, the present invention will be specifically described.

[0013] The method for manufacturing a film laminate of the present invention comprises, in an inline manner in this order, a printing step of applying an active energy ray-curable printing ink (hereinafter, may be simply referred to as "ink") to a first base film made of at least a plastic film, an adhesive application step of applying an adhesive, and a laminating step of laminating a second base material, and further has a curing step of irradiating active energy rays to cure the active energy ray-curable printing ink, at least after the adhesive application step. The film laminate in the present invention has, on at least the first base film, a cured product of the ink, a cured product of the adhesive, and a second base film. The cured product of the ink may be at necessary positions according to the pattern, and does not necessarily have to be on the entire surface of the film laminate.

[0014] A first aspect of the method for manufacturing a film laminate of the present invention uses an active energy ray-curable adhesive as the adhesive in the adhesive application step, and has the above-described printing step, adhesive application step, laminating step, and curing step in this order. That is, it is a method of curing the ink and the adhesive with active energy rays after applying the ink and the adhesive and laminating the second base material.

[0015] Further, in the second aspect of the method for manufacturing the film laminate of the present invention, a solventless isocyanate-based adhesive is used as the adhesive in the adhesive application step, and the above-described printing step, adhesive application step, curing step, and laminating step are performed in this order. That is, it is a method of laminating a second base material after curing the ink with active energy rays in a state where the adhesive is applied on the ink. In any aspect, performing from the printing step to the laminating step or the curing step in a continuous series of manufacturing processes, that is, performing inline, can reduce the lead time and improve productivity. Further, compared to offline manufacturing in which the printing step and the laminating step are performed discontinuously, the processing loss occurring in the laminating step can be reduced. Furthermore, when the ink is cured by active energy rays, since the adhesive and / or the second base material are present on the ink surface, insufficient curing due to the ink surface being exposed to oxygen is suppressed, and the adhesion between the second base material and the ink and the curability of the ink can be improved.

[0016] FIG. 1 shows a schematic diagram of an example of the first aspect of the method for manufacturing the film laminate of the present invention. Ink is applied to the first base film 1 by the offset printing unit 2 of a central drum type lithographic printing press (printing step). Subsequently, on the same cylinder, an active energy ray curable adhesive is applied by the flexographic printing unit 3 of the central drum type lithographic printing press (adhesive application step), and then the second base material 5 is laminated using the nip roll 4 (laminating step). Subsequently, active energy rays are irradiated by the electron beam irradiator 6 to simultaneously cure the ink and the active energy ray curable adhesive (curing step).

[0017] FIG. 2 shows a schematic view of an example of a second aspect of the method for manufacturing a film laminate of the present invention. Ink is applied to the first base film 1 by the offset printing unit 2 of a central drum type offset printing press (printing step). Subsequently, on the same cylinder, a solventless isocyanate curable adhesive is applied by the flexographic printing unit 3 of the central drum type offset printing press (adhesive application step), and then active energy rays are irradiated by the electron beam irradiation device 6 to cure the ink through the solventless isocyanate curable adhesive (curing step). Subsequently, the second base material 5 is laminated using the nip roll 4 (laminating step).

[0018] The first base film is made of a plastic film and imparts strength to withstand the tension generated in the printing step and the like to the film laminate. Examples of the plastic film include a stretched polyester film, a stretched polyamide film, a stretched polypropylene (OPP) film, an unstretched polypropylene film (CPP), and a polyethylene film. Among these, they can be appropriately selected according to the required properties such as the leveling property of the ink, the appearance quality, and the barrier property for protecting the contents, and two or more of them may be used. These plastic films may have an easy adhesion layer, an anchor layer, a metal vapor deposition layer, a metal oxide layer, or the like.

[0019] From the viewpoints of processability and cost, the thickness of the first base film is preferably 50 μm or less, and more preferably 30 μm or less.

[0020] Examples of the second base material include a stretched film, a metal film, and a hot melt film (sealant film). Two or more of these may be used.

[0021] By using a stretched film as the second substrate, the strength of the film laminate can be improved, and in packaging applications, the effect of protecting the contents can be enhanced. Examples of the stretched film include a stretched polyamide film, a stretched polyester film, and a stretched polyolefin film. The stretched film may have a metal vapor deposition layer, a metal oxide layer, etc., and in packaging applications, it can suppress the deterioration of the contents due to the permeation of oxygen, water vapor, light, etc. into the interior.

[0022] By using a metal film as the second substrate, the deterioration of the contents due to the permeation of oxygen, water vapor, light, etc. into the interior can be more effectively suppressed. Also, the infiltration of the contents into the outer layer side of the metal film can be suppressed, and the deterioration of the outer layer part can be suppressed. Examples of the metal film include aluminum foil.

[0023] By using a heat-melt film as the second substrate, a pouch can be formed by heat-melting (heat-sealing) the laminated part of the first substrate and the second substrate. Examples of the heat-melt film include an unstretched polypropylene film (CPP), a linear low-density polyethylene film (LLDPE), and a low-density polyethylene film (LDPE).

[0024] From the viewpoints of processability and cost, in the case of a stretched film, the thickness of the second substrate is preferably 50 μm or less, more preferably 30 μm or less. In the case of a metal film, it is preferably 20 μm or less, more preferably 12 μm or less. In the case of a heat-melt film, it is preferably 20 to 120 μm.

[0025] The active energy ray-curable printing ink in the present invention refers to an ink containing a component having an ethylenically unsaturated double bond. It is preferably composed of a resin and a compound having an ethylenically unsaturated double bond. By including a resin, fluidity suitable for the ink can be imparted, and splashing (misting) of the ink during printing can be suppressed. Even if the resin has an ethylenically unsaturated double bond, it is classified as a resin. Examples of the compound having an ethylenically unsaturated double bond include monomers and oligomers having an ethylenically unsaturated double bond. The molecular weight of the monomer is preferably less than 1,500. An oligomer refers to a polymer with a relatively low molecular weight, and its weight average molecular weight is preferably 1,500 or more and 15,000 or less. It is preferable to contain urethane (meth)acrylate as the oligomer having an ethylenically unsaturated double bond. Here, "(meth)acrylate" is a general term including acrylate and methacrylate. By containing urethane (meth)acrylate, the cohesive force of the ink can be improved by the hydrogen bond interaction derived from the urethane bond. Therefore, the viscosity difference from the adhesive can be increased, and reverse trapping can be suppressed. In the second aspect, the affinity with the solventless isocyanate-curable adhesive can be improved, and the adhesion to the second substrate can be further improved. Furthermore, other monomers having an ethylenically unsaturated double bond, pigments, acylphosphine oxide compounds, etc. may be contained. Examples of such an ink include the printing ink disclosed in International Publication No. 2020 / 235557.

[0026] Examples of the resin contained in the ink include acrylic resin, styrene acrylic resin, styrene maleic acid resin, rosin-modified maleic acid resin, rosin-modified acrylic resin, epoxy resin, polyester resin, polyurethane resin, phenol resin, etc. Two or more of these may be used. Among these, acrylic resin, styrene acrylic resin, and styrene maleic acid resin are preferably used from the viewpoints of ease of synthesis, compatibility with other components, dispersibility of pigments, etc.

[0027] The resin contained in the ink preferably has an ethylenically unsaturated double bond and a hydrophilic group. By having an ethylenically unsaturated double bond, in the curing process, a crosslinked structure is formed by reaction with radical species, so that the sensitivity of the ink to active energy rays can be improved. Further, a strong covalent bond is formed by reaction with the acryloyl group of urethane (meth) acrylate, so that the adhesion to the first base film and the resistance to heat water treatment of the film laminate can be improved. Furthermore, in the first aspect, a strong covalent bond is formed by reaction with the acryloyl group contained in the active energy ray curable adhesive, so that the adhesion between the ink and the second base material can be further improved. On the other hand, by having a hydrophilic group, when urethane (meth) acrylate is contained, due to the strong interaction with the urethane bond, the cohesive force of the ink increases, so that the resistance to heat water treatment of the film laminate and the stain resistance of the ink can be improved, and reverse trapping can be suppressed. Here, the stain resistance means that in the non-printing area where the ink is not intended to transfer, it is difficult for the ink to adhere to the printing plate and transfer to the first base film (ground stain). Reverse trapping refers to a phenomenon in which the viscosity of the adhesive becomes higher than that of the ink, and the ink is drawn to the adhesive side.

[0028] Examples of the hydrophilic group include a hydroxyl group, an amino group, a mercapto group, a carboxyl group, a sulfo group, a phosphoric acid group, etc. Two or more of these may be included. When urethane (meth) acrylate is contained, among these, a carboxyl group and a hydroxyl group, which have good interaction with the urethane bond, are preferable, and it is more preferable to have a carboxyl group and a hydroxyl group.

[0029] The acid value of the resin having an ethylenically unsaturated group, a carboxyl group and a hydroxyl group is preferably 75 mgKOH / g or more and preferably 150 mgKOH / g or less. Here, the acid value of the resin can be measured in accordance with the neutralization titration method in Section 3.1 of the test method of JIS K 0070:1992. Further, the iodine value of the resin having an ethylenically unsaturated group, a carboxyl group and a hydroxyl group is preferably 1.5 mol / kg or more and preferably 2.5 mol / kg or less. Here, the iodine value of the resin can be measured by the method described in Section 6.0 of the test method of JIS K 0070:1992.

[0030] The resin having an ethylenically unsaturated group, a carboxyl group and a hydroxyl group can be obtained, for example, by copolymerizing a monomer having a carboxyl group, a monomer having a hydroxyl group and, if necessary, other monomers, and then adding an ethylenically unsaturated compound having a glycidyl group.

[0031] From the viewpoint of improving the resistance of the film laminate to heat water treatment and the like and the stain resistance of the ink to the substrate, and increasing the viscosity of the ink to suppress reverse trapping, the weight average molecular weight of the resin is preferably 20,000 or more. On the other hand, from the viewpoint of improving the fluidity of the ink, the weight average molecular weight of the resin is preferably 50,000 or less. Here, the weight average molecular weight of the resin refers to the polystyrene conversion value calculated using gel permeation chromatography (GPC).

[0032] From the viewpoint of easily adjusting the viscosity α described later within the preferable range described later, the content of the resin in the ink is preferably 5% by mass or more, more preferably 10.0% by mass or more. On the other hand, from the viewpoint of easily adjusting the viscosity α described later within the preferable range described later, the content of the resin in the ink is preferably 40% by mass or less, more preferably 15% by mass or less.

[0033] Urethane (meth)acrylate can be obtained by the reaction of a polyol, an isocyanate, and a (meth)acrylate. More specifically, methods such as adding a polyol to an addition reaction product of an isocyanate and a (meth)acrylate can be mentioned. Examples of the polyol include polyether polyol, polyester polyol, polycarbonate polyol, and the like. Examples of the isocyanate include alicyclic isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate, etc., from the viewpoints of heat resistance and safety. Also, except for applications where there is a risk of elution into the contents of foods, etc. that are heat-sterilized, from the viewpoint of cost, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI) are preferable. As the (meth)acrylate, 2-hydroxyethyl acrylate is preferable.

[0034] Since the segment derived from the polyol has high flexibility, the higher the molecular weight of the polyol, the more the flexibility and shape followability of the urethane (meth)acrylate are improved, and thus the adhesion to the second substrate can be further improved. On the other hand, from the viewpoints of sensitivity to active energy rays and curability, it is preferable that the molecular weight of the polyol is small and the (meth)acrylate ratio is high.

[0035] In the present invention, from the viewpoint of improving the sensitivity to active energy rays and further improving the curability, the weight average molecular weight of the urethane (meth)acrylate is preferably 500 or more. On the other hand, from the viewpoint of improving soil resistance and ink transferability, the weight average molecular weight of the urethane (meth)acrylate is preferably 10,000 or less.

[0036] From the viewpoints of compatibility with other ink components and easily adjusting the viscosity α described later to a preferable range described later, it is preferable that the urethane (meth)acrylate has two or more (meth)acrylates in one molecule, and more preferably has two.

[0037] As the monomer having an ethylenically unsaturated double bond, (meth)acrylate having a hydroxyl group is preferable, and the resistance of the film laminate to heat water treatment or the like can be improved by the interaction with the hydrophilic group in the resin. Examples of the (meth)acrylate having a hydroxyl group include pentaerythritol tri(meth)acrylate, diglycerin tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, and the like.

[0038] From the viewpoint of easily adjusting the viscosity α described later within the preferable range described later, the content of the compound having an ethylenically unsaturated double bond in the ink is preferably 50% by mass or more, more preferably 65% by mass or more. On the other hand, from the viewpoint of easily adjusting the viscosity α described later within the preferable range described later, the content of the compound having an ethylenically unsaturated double bond in the ink is preferably 80% by mass or less. Among these, the content of urethane (meth)acrylate is preferably 1% by mass or more in order to improve the adhesion to the substrate, and preferably 20% by mass or less from the viewpoints of compatibility with other ink components and easily adjusting the viscosity α described later within the preferable range described later.

[0039] Examples of the pigment include inorganic pigments and organic pigments. When the pigment has a specific gravity of 2 or less, the content of the pigment in the ink is preferably 15% by mass or more and preferably 40% by mass or less. When the pigment has a specific gravity greater than 2, the content of the pigment is preferably 40% by mass or more and preferably 50% by mass or less.

[0040] Since acylphosphine oxide compounds absorb light in the long wavelength region of 350 nm or longer, they have high sensitivity even when pigments that absorb or reflect ultraviolet light are included. In addition, since acylphosphine oxide compounds have a photobleaching effect in which light absorption disappears after the reaction, they exhibit excellent internal curability. In particular, by combining with a (meth)acrylate having a hydroxyl group, the compatibility is improved and the sensitivity to active energy rays can be further improved. Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenyl-phosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl-phosphine oxide, and the like.

[0041] From the viewpoint of improving sensitivity, the content of the acylphosphine oxide compound in the ink is preferably 5% by mass or more. On the other hand, from the viewpoint of improving storage stability, the content of the acylphosphine oxide compound is preferably 10% by mass or less.

[0042] The viscosity α of the ink at a temperature of 30 °C and a shear rate of 300 s -1 is preferably 10 Pa·s or more and 40 Pa·s or less. Such conditions of temperature and shear rate are assumed based on the temperature during printing and the shear rate when the ink transfers to the first base film. By setting such viscosity α to 10 Pa·s or more, the stain resistance to the substrate can be improved. The viscosity α is more preferably 15 Pa·s or more, and even more preferably 20 Pa·s or more. On the other hand, by setting the viscosity α to 40 Pa·s or less, the ink transferability and leveling property to the first base film can be improved. The viscosity α is more preferably 35 Pa·s or less, and even more preferably 30 Pa·s or less.

[0043] Here, the viscosity α of the ink in the present invention can be measured using a cone plate jig with a dynamic viscoelasticity measuring device (rheometer). The ink is sandwiched between the cone plate and the lower plate, and the viscosity of the ink is measured from the torque applied to the cone plate when the cone plate rotates. The shape of the cone plate is a diameter of 40 mm and an inclination angle of 1°, and the gap between the cone plate and the lower plate is 81 μm. In advance, the dynamic viscoelasticity measuring device is heated to 30°C. After placing the ink on the lower plate and setting the cone plate jig at the measurement position, it is left standing at 30°C for 3 minutes, and the viscosity is measured by continuously logarithmically changing the shear rate in the range of shear rates of 1 to 490 s -1 from the approximate formula of shear rate and viscosity obtained by continuously logarithmically changing the shear rate in the range of -1 to obtain the viscosity α at a shear rate of 300 s

[0044] The viscosity α of the ink can be adjusted to the aforementioned range, for example, by using the aforementioned preferred resin, setting the contents of the resin and the compound having an ethylenically unsaturated double bond within the aforementioned preferred ranges, and using urethane (meth)acrylate as the compound having an ethylenically unsaturated double bond.

[0045] As the adhesive, an active energy ray-curable adhesive or a solvent-free isocyanate-curable adhesive is preferred. Since these generally do not contain an organic solvent to the extent that a drying process is required, the drying process is unnecessary and the productivity is excellent. Here, "solvent-free type" means that the content of the organic solvent is 5% by mass or less. The content of the organic solvent is preferably 3% by mass or less.

[0046] The active energy ray-curable adhesive preferably contains a resin and a compound having an ethylenically unsaturated double bond. By containing the resin, the adhesive can be applied well in appearance on the uncured ink. In addition, the flexibility of the cured film of the active energy ray-curable adhesive can be moderately improved. Further, by containing a compound having an ethylenically unsaturated double bond, the viscosity of the active energy ray-curable adhesive can be easily adjusted to a range suitable for processing, and the appearance of the film laminate can be improved. Also, it can be cured by active energy rays. Note that even if the resin has an ethylenically unsaturated double bond, it shall be classified as a resin.

[0047] Also, the resin preferably includes an isocyanate-curable resin. Here, the isocyanate-curable resin contains a polyol compound and a polyisocyanate compound. By including the isocyanate-curable resin, the flexibility of the cured film of the adhesive can be moderately improved. Also, when the laminate obtained by applying the adhesive and laminating it with the second substrate is aged, the adhesion strength as a laminate can be further improved.

[0048] The active energy ray-curable adhesive may further contain a leveling agent, an extender pigment, etc. as required.

[0049] Examples of the resin in the active energy ray-curable adhesive include those exemplified as the resin for the raw material of the ink. Among these, from the viewpoints of adhesion to the ink, film strength after curing, etc., acrylic resin, styrene-acrylic resin, styrene-maleic acid resin, and polyurethane resin are preferably used.

[0050] The resin in the active energy ray-curable adhesive preferably has an ethylenic double bond group, and the strength of the cured film of the adhesive can be further improved.

[0051] The weight average molecular weight of the resin in the active energy ray-curable adhesive is preferably 20,000 or more and 50,000 or less. Here, the weight average molecular weight of the resin refers to the polystyrene conversion value calculated using gel permeation chromatography (GPC).

[0052] From the viewpoint of suppressing repellency during coating and further improving the flexibility of the cured film, the resin content in the active energy ray-curable adhesive is preferably 10% by mass or more. On the other hand, from the viewpoint of appropriately reducing the viscosity with respect to the ink to suppress reverse trapping and easily adjusting the viscosity (β1) described later to the preferred range described later, it is preferably 40% by mass or less.

[0053] As the compound having an ethylenically unsaturated double bond, a monomer having an ethylenically unsaturated double bond is preferable. Since it has high curability, it preferably has two or more ethylenically unsaturated double bonds in one molecule. On the other hand, from the viewpoint of improving the flexibility of the cured film of the adhesive, it preferably has six or less ethylenically unsaturated double bonds in one molecule. Among these, pentaerythritol tri(meth)acrylate, diglycerin tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, and ethoxylated trimethylolpropane tri(meth)acrylate are preferable.

[0054] From the viewpoint of improving the strength of the cured film of the adhesive and easily adjusting the viscosity β1 described later to the preferred range described later, the content of the compound having an ethylenically unsaturated double bond in the active energy ray-curable adhesive is preferably 60% by mass or more, and from the viewpoint of improving the flexibility of the cured film of the adhesive, it is preferably 90% by mass or less.

[0055] The active energy ray-curable adhesive is preferably a solvent-free type, that is, the content of the organic solvent is 5% by mass or less, and the productivity can be further improved by eliminating the drying process. The content of the organic solvent is more preferably 3% by mass or less.

[0056] The viscosity β1 of the active energy ray-curable adhesive at a temperature of 30°C and a shear rate of 300 s -1 is preferably 0.1 Pa·s or more and 20 Pa·s or less. Such temperature and shear rate conditions are assumed based on the temperature during adhesive coating and the shear rate when the adhesive transfers onto the first base film and the ink transferred thereto. By setting the viscosity β1 to 0.1 Pa·s or more, the adhesiveness with the second base material before the curing process after lamination can be improved. On the other hand, by setting the viscosity β1 to 20 Pa·s or less, the leveling property of the adhesive can be improved, and reverse trapping can be suppressed by making the viscosity lower than that of the ink. The viscosity β1 is more preferably 10 Pa·s or less.

[0057] The ratio β1 / α of the viscosity β1 of the active energy ray-curable adhesive to the viscosity α of the ink is preferably 0.01 or more and 1.0 or less. By setting the viscosity ratio β1 / α to 0.01 or more, the adhesive can be applied well in appearance on the uncured ink. On the other hand, by setting the viscosity ratio β1 / α to 1.0 or less, reverse trapping can be suppressed. By suppressing reverse trapping, an adhesive coating film can be formed uniformly, and the adhesiveness as a laminate can also be improved.

[0058] To set the viscosity ratio β1 / α within the above range, the aforementioned resin and a monomer having an ethylenically unsaturated double bond may be used for the ink and the adhesive. Further, by using a compound having all or any of the following characteristics for the monomer having an ethylenically unsaturated double bond that dissolves the resin used for the adhesive and appropriately adjusting its ratio, the viscosity can be controlled. (1) Having hydrophilicity by ethoxylation. Thereby, the compatibility of the resin can be improved, and the viscosity can be moderately increased. (2) Having an alicyclic structure or a linear alkane structure. Thereby, the cohesive force of the adhesive resin solution can be suppressed, and the viscosity can be decreased. (3) Having a double bond equivalent of 100 or more. Thereby, the hydrogen bonding force by the acrylic group can be suppressed, and the adhesive viscosity can be suppressed.

[0059] Here, the viscosity β1 of the active energy ray-curable adhesive in the present invention can be measured in the same manner as the above-described ink.

[0060] The viscosity β1 of the active energy ray-curable adhesive can be adjusted to the above range, for example, by using the above-described preferable resin and a compound having an ethylenically unsaturated double bond, setting the molecular weight of the resin, and the contents of the resin and the compound having an ethylenically unsaturated double bond within the above-described preferable ranges.

[0061] The solventless isocyanate-curable adhesive preferably contains an isocyanate-curable resin and a compound having an ethylenically unsaturated double bond. By containing the isocyanate-curable resin, the adhesive can be applied well in appearance on the uncured ink. Further, the flexibility of the cured film of the adhesive can be moderately improved. Also, by containing a compound having an ethylenically unsaturated double bond, the viscosity of the solventless isocyanate-curable adhesive can be easily adjusted to a range suitable for processing, and the appearance of the film laminate can be improved. Further, it can be cured by active energy rays.

[0062] The isocyanate-curable resin contains at least a polyol compound and a polyisocyanate compound.

[0063] Examples of the polyol compound include polyether polyol, polyester polyol, polycarbonate polyol, etc. Two or more of these may be included. Among these, from the viewpoint of productivity, polyether polyol and polyester polyol are preferable. From the viewpoint of improving the leveling property of the solventless isocyanate-curable adhesive coating film, polyether polyol is more preferable, and from the viewpoint of improving heat resistance in high-temperature sterilization applications, polyester polyol is more preferable.

[0064] Examples of the polyisocyanate include compounds having an aromatic isocyanate, an aliphatic isocyanate, an alicyclic isocyanate, etc. at the terminal. Two or more of these may be used. Among these, from the viewpoint of safety, compounds having an aliphatic isocyanate or an alicyclic isocyanate at the terminal are preferred, and from the viewpoint of adjusting the reaction rate and viscosity, compounds having an aliphatic diisocyanate, an alicyclic diisocyanate, or an aromatic alicyclic diisocyanate at the terminal are more preferred.

[0065] Examples of the isocyanate-curing type resin include combinations such as "Takelac" (registered trademark) A-244B / "Takenate" (registered trademark) A-244A, "Takelac" (registered trademark) A-246B / "Takenate" (registered trademark) A-246A, "Takelac" (registered trademark) A-248B / "Takenate" (registered trademark) A-246A manufactured by Mitsui Chemicals, Inc., using a polyether polyol as the polyol compound and an aromatic polyisocyanate as the polyisocyanate, and "EA-370A / EA-370B" manufactured by Toyo Morton Co., Ltd., and combinations such as "Takelac" (registered trademark) A-670B / "Takenate" (registered trademark) A-670A, "Takelac" (registered trademark) A-666 / "Takenate" (registered trademark) A-65 manufactured by Mitsui Chemicals, Inc., using a polyester polyol as the polyol compound and an aliphatic or alicyclic or aromatic alicyclic polyisocyanate as the polyisocyanate, and "TSN-4864A / TSN-4864B-3" manufactured by Toyo Morton Co., Ltd.

[0066] Examples of the compound having an ethylenically unsaturated double bond include monomers, oligomers, resins, etc. having an ethylenically unsaturated double bond. From the viewpoint of compatibility with the isocyanate-curing type resin, urethane (meth)acrylate is more preferred. As the urethane (meth)acrylate, those exemplified as the urethane (meth)acrylate in the ink are preferred.

[0067] Examples of the resin having an ethylenically unsaturated double bond include acrylic resins, styrene-acrylic resins, styrene-maleic resins, rosin-modified maleic resins, rosin-modified acrylic resins, polyurethane resins, etc. Two or more of these may be included. Among these, acrylic resins, styrene-acrylic resins, and styrene-maleic resins are preferred from the viewpoints of ease of synthesis, adhesion to ink, coating film strength, etc.

[0068] As the monomer having an ethylenically unsaturated double bond, since it has high curability, it preferably has two or more ethylenically unsaturated double bonds in one molecule. On the other hand, from the viewpoints of improving the flexibility of the cured film of the adhesive and improving the adhesiveness to the second substrate before the laminating step, it preferably has six or less ethylenically unsaturated double bonds in one molecule, and more preferably four or less. As such a monomer, those exemplified as the monomer having an ethylenically unsaturated double bond in the active energy ray-curable adhesive are preferred.

[0069] In the solventless isocyanate-curable adhesive, the total content of the compound having an ethylenically unsaturated double bond is preferably 1% by mass or more and 30% by mass or less. Here, the total content of the compound having an ethylenically unsaturated double bond means the content when only a monomer, oligomer, or resin having an ethylenically unsaturated double bond is included, and the total content when two or more of these are included. By setting the total content to 1% by mass or more, the adhesion to the second substrate and the leveling property can be further improved. The total content is more preferably 5% by mass or more. On the other hand, by setting the total content to 30% by mass or less, the adhesion to the second substrate after the isocyanate curing component is cured by aging can be further improved.

[0070] The solventless isocyanate-curable adhesive may further contain a leveling agent, an extender pigment, etc. as required.

[0071] For the solvent-free isocyanate-curing adhesive at a temperature of 30°C and a shear rate of 300 s -1 the viscosity β2 is preferably 1 Pa·s or more and preferably 20 Pa·s or less. Also, for the solvent-free isocyanate-curing adhesive at a temperature of 80°C and a shear rate of 300 s -1 the viscosity β2’ is preferably 0.05 Pa·s or more and preferably 5 Pa·s or less. Such temperature and shear rate conditions are assumed based on the temperature range of 30 to 80°C during adhesive coating and the shear rate when the adhesive transfers onto the first substrate film and the ink transferred thereon.

[0072] By setting the viscosity β2 to 1 Pa·s or more, the adhesive can be well-applied in appearance on the uncured ink, and the adhesiveness with the second substrate before the lamination process after the curing process can be improved. The viscosity β2 is more preferably 5 Pa·s or more. On the other hand, by setting the viscosity β2 to 20 Pa·s or less, the leveling property can be improved. The viscosity β2 is more preferably 15 Pa·s or less.

[0073] Also, by setting the viscosity β2’ to 0.05 Pa·s or more, the adhesive can be well-applied in appearance on the uncured ink, and the adhesiveness with the second substrate before the lamination process after the curing process can be improved. The viscosity β2’ is more preferably 0.08 Pa·s or more. On the other hand, by setting the viscosity β2’ to 5 Pa·s or less, the leveling property can be improved.

[0074] The ratio β2 / α of the viscosity β2 of the solvent-free isocyanate-curing adhesive to the ink viscosity α is preferably 0.01 or more and 0.50 or less. By setting the viscosity ratio β2 / α to 0.01 or more, the adhesive can be well-applied in appearance on the uncured ink. On the other hand, by setting the viscosity ratio β2 / α to 0.50 or less, the occurrence of orange peel, etc. can be suppressed in the adhesive coating.

[0075] To make the ratio of viscosities β2 / α fall within the above range, the aforementioned ink and the adhesive may use the aforementioned resin and a compound having an ethylenically unsaturated double bond. Further, by using a monomer having an ethylenically unsaturated double bond and a compound having all or any of the following characteristics, and appropriately adjusting the ratio thereof, it becomes possible to control the viscosity. (1) Having hydrophilicity by ethoxylation. Thereby, the compatibility of the resin can be improved and the viscosity can be moderately increased. (2) Having a double bond equivalent of 100 or more. Thereby, the hydrogen bonding force due to the acrylic group can be suppressed and the adhesive viscosity can be suppressed.

[0076] Here, the viscosities β2 and β2' of the active energy ray curable adhesive in the present invention can be measured in the same manner as the viscosity of the aforementioned ink.

[0077] The viscosities β2 and β2' of the solventless isocyanate curable adhesive can be adjusted to the above range, for example, by using the aforementioned preferred isocyanate curable adhesive and a compound having an ethylenically unsaturated double bond, and setting the content of the compound having an ethylenically unsaturated double bond within the aforementioned preferred range.

[0078] Next, each step of the first aspect and the second aspect will be described.

[0079] The first aspect of the method for manufacturing a film laminate of the present invention has a printing step, an adhesive application step, a laminating step, and a curing step in this order.

[0080] First, the printing process will be described. In the first aspect, the aforementioned ink is applied to the first base film. As the printing method, offset printing (lithography) or flexographic printing, which does not require a drying process and can laminate the uncured ink multiple times (Wet-on-Wet printing), is preferred. Among them, offset printing is more preferred from the perspective of easily suppressing reverse trapping of the ink. Waterless offset printing is even more preferred because it does not contaminate the ink with a small amount of moisture by not using dampening water and can efficiently use the radicals generated by active energy ray irradiation for the curing reaction.

[0081] Next, the adhesive application process will be described. In the first aspect, an active energy ray-curable adhesive is applied inline to the printed material with the ink applied to the first base material by the aforementioned printing process. As the adhesive application method, offset printing or flexographic printing is preferred because the adhesive is applied on top of the uncured ink. Flexographic printing is more preferred because it is easy to increase the film thickness of the adhesive and is suitable for coating materials with relatively low viscosity. The coating temperature of the adhesive is preferably 20°C to 40°C in order to maintain good viscosity and coating appearance during coating.

[0082] Examples of printing machines preferably used in the printing process and the adhesive application process include the center drum type printing machine "CI8" (manufactured by COMEXI). The printing machine may be connected to a coater machine having an existing active energy ray curing unit.

[0083] Next, the lamination process will be described. In the first aspect, the second base material described above is laminated by bonding it with a nip roll to the laminate in which the ink and the adhesive are sequentially applied to the first base material. The nip pressure is preferably 0.1 MPa or more and 0.6 MPa or less. The nip roll temperature is preferably 40°C or more and 80°C or less.

[0084] Next, the curing process will be described. In the first aspect, by irradiating active energy rays, the ink and the active energy ray-curable adhesive on the first base film can be rapidly cured. The active energy rays may be those having the excitation energy necessary for the curing reaction, and for example, electron beams or ultraviolet rays are preferably used. When using an electron beam, it is possible to cure without including a photoinitiator in the ink, so it is particularly suitable for applications where migration of low molecular weight compounds to the contents and odor specific to the initiator are avoided, such as pharmaceutical packaging and food packaging.

[0085] When the active energy rays are irradiated from both sides of the first base material and the second base material, it is preferable because the curability of the ink and / or the adhesive can be improved. In particular, when irradiating an electron beam in a state where the first base material and the second base material are laminated as in the first aspect, by irradiating the electron beam from both sides, it is possible to irradiate an electron beam sufficient to cure the ink and / or the adhesive even with electron beam irradiation at a low acceleration voltage, so that it is possible to suppress the alteration of the base material due to the electron beam.

[0086] When irradiating the active energy rays from only one of the first base film side and the second base material side, from the viewpoint of more effectively promoting the curing of the ink by the active energy rays, it is preferable to irradiate from the side with a smaller thickness or the side with a smaller specific gravity of the base material (when using an aluminum foil for the second base material, the side that is not the aluminum foil). Further, when using a base material such as a polypropylene film that has a relatively large change in physical properties due to an electron beam, the acceleration voltage that contributes to the penetration depth of the electron beam and the irradiation amount that contributes to the density of the electron beam are preferably made small within the range in which the ink and / or the adhesive is cured.

[0087] When curing with an electron beam, an electron beam apparatus having an energy ray of 100 to 500 keV is preferably used.

[0088] The irradiation dose of the electron beam is preferably 10 kGy or more from the viewpoint of improving the curability of the ink and the active energy ray-curable adhesive. On the other hand, the irradiation dose of the electron beam is preferably 80 kGy or less from the viewpoint of suppressing the deterioration and discoloration of the first base film and the second base material.

[0089] The acceleration voltage contributing to the penetration depth of the electron beam is preferably 80 kV or more and 300 kV or less. By being 80 kV or more, the electron beam dose can be stably generated. Further, by being 300 kV or less, more preferably 150 kV or less, the change in physical properties of the base film can be suppressed.

[0090] When curing with ultraviolet rays, for example, ultraviolet lamps such as high-pressure mercury lamps, xenon lamps, metal halide lamps, and light-emitting diodes (LEDs) are preferably used. A light-emitting diode emitting spectral lines with a wavelength of 350 to 420 nm is preferable from the viewpoints of power saving and cost reduction.

[0091] In the curing step, the elastic modulus of the cured coating film of the active energy ray-curable adhesive is preferably 5 MPa or more, more preferably 10 MPa or more, from the viewpoint of improving the flexibility and strength of the coating film. On the other hand, the elastic modulus of the cured coating film of the active energy ray-curable adhesive is preferably 600 MPa or less, more preferably 500 MPa or less, from the viewpoint of suppressing the occurrence of cracks and the like. The elastic modulus of the coating film is measured by a nanoindenter.

[0092] Next, a second aspect of the present invention will be described. The second aspect of the method for manufacturing the film laminate of the present invention has a printing step, an adhesive coating step, a curing step, and a lamination step in this order.

[0093] The printing step and the lamination step are the same as those in the first aspect.

[0094] In the adhesive application step, a solventless isocyanate-curing adhesive is applied in-line without going through the winding step to the printed matter with the ink applied to the first substrate in the above-described printing step. Examples of the adhesive application method include the methods exemplified in the first aspect, and flexographic printing is preferred. The coating temperature of the adhesive is preferably 20°C to 80°C in order to maintain good viscosity and coating appearance during coating.

[0095] Examples of the printing machine preferably used in the printing step and the adhesive application step include those exemplified in the first aspect.

[0096] Next, the curing step will be described. Similar to the first aspect, in the curing step, by irradiating active energy rays, the ink on the first substrate film can be quickly cured. Also, by semi-curing the solventless isocyanate-curing adhesive to increase the apparent molecular weight, the initial adhesion strength can be improved. In the second aspect, since the second substrate is not irradiated with electron beams, physical property changes of the second substrate due to electron beams can be prevented.

[0097] The active energy rays may be those having the excitation energy required for the curing reaction, and for example, electron beams, ultraviolet rays, etc. are preferably used.

[0098] From the viewpoint of preventing appearance defects in post-processing, the initial peel strength of the laminate obtained by the method for producing a film laminate of the present invention is preferably 0.5 N or more, more preferably 0.8 N or more, still more preferably 1.0 N or more, and even more preferably 1.5 N or more.

[0099] In particular, from the viewpoint of maintaining good strength as a packaging material, the peel strength of the laminate obtained in the second aspect after aging is preferably 1.5 N or more, more preferably 2.0 N or more, and even more preferably 3.0 N or more. Here, the peel strength of the laminate is measured by (8) of the evaluation method in the examples described later.

Examples

[0100] The evaluation methods in each example and comparative example are shown below.

[0101] (1) Weight-average molecular weight of the resin The weight-average molecular weight of the resin used in each example and comparative example was measured by gel permeation chromatography (GPC) with tetrahydrofuran as the mobile phase.

[0102] The resin was added to tetrahydrofuran so that the resin concentration became 0.25% by mass, and using a shaker MIX-ROTAR VMR-5 (manufactured by AS ONE Corporation), it was stirred and dissolved at a rotation speed of 100 rpm for 5 minutes, and filtered using a 0.2 μm filter Z227536-100EA (manufactured by SIGMA), and the filtrate was used as a measurement sample. Using a gel permeation chromatography apparatus HLC-8220 (manufactured by Tosoh Corporation), detection was performed using the RI detector built into the apparatus. The columns used were those connected in the order of TSKgel SuperHM-H (manufactured by Tosoh Corporation), TSKgel SuperHM-H (manufactured by Tosoh Corporation), and TSKgel SuperH2000 (manufactured by Tosoh Corporation). The injection volume was 10 μL, the analysis time was 30 minutes, the flow rate was 0.4 mL / min, and the column temperature was 40°C. The weight-average molecular weight of the resin was calculated from the calibration curve prepared using a polystyrene standard substance.

[0103] (2) Acid value of the resin Based on the neutralization titration method in Section 3.1 of the test method of JIS K 0070:1992, the acid value of the resin was determined.

[0104] (3) Iodine value of the resin Based on the method described in Section 6.0 of the test method of JIS K 0070:1992, the iodine value of the resin was determined.

[0105] (4) Hydroxyl value of the monomer Based on the neutralization titration method in Section 7.1 of the test method of JIS K 0070:1992, the hydroxyl value of the monomer was measured.

[0106] (5) Ink viscosity α Regarding the inks used in each example and comparative example, using a dynamic viscoelasticity measuring device Pyhsia MCR301 (manufactured by Anton Paar), with a shape of a cone plate having a diameter of 40 mm and an inclination angle of 1.00°, and a cone plate jig with a gap of 81 μm between the cone plate and the lower plate, the viscosity was measured according to the following procedure. First, the dynamic viscoelasticity measuring device was preheated to 30 °C in advance. 0.7 mL of the ink was sandwiched between the preheated cone plate and the lower plate, and after setting it at the measurement position, it was allowed to stand at 30 °C for 3 minutes. Next, at a temperature of 30 °C, the shear rate was continuously logarithmically changed in the range of 1 to 490 s -1 From the approximate curve of the shear rate and viscosity obtained by measuring the viscosity while continuously logarithmically changing the shear rate in the range of, the viscosity at a shear rate of 300 s -1 was determined.

[0107] (6) Adhesive viscosities β1, β2, β2' Regarding the active energy ray-curable adhesives and solvent-free isocyanate-curable adhesives used in each example and comparative example, viscosities β1 and β2 were measured in the same manner as the ink viscosity α described in the above item (5).

[0108] Regarding the solvent-free isocyanate-curable adhesives used in each example and comparative example, viscosity β2' was measured in the same manner as viscosities β1 and β2, except that the preheating temperature and measurement temperature of the apparatus were set to 80 °C.

[0109] (7) Curing property of the ink A film laminate was produced in the same manner as in each example and comparative example, except that a PET film "Embret" (registered trademark) PET12 μm (manufactured by Unitika Ltd.) was used instead of film A as the first substrate. Since the inks in the obtained film laminates had undergone the same curing process as in each example and comparative example under the same conditions, the curing properties of the inks in the film laminates obtained here were evaluated for the inks in the film laminates obtained in each example and comparative example.

[0110] The obtained film laminate was allowed to stand at 40 °C for 72 hours, i.e., aged. After that, the PET film, which is the first substrate, was peeled off, and the surface of the exposed ink cured product was rubbed with a cloth (No. 6 canvas) dipped in methyl ethyl ketone, and the presence or absence of coloring of the cloth with the ink was visually observed. The ink curability was evaluated according to the following criteria based on the number of reciprocations until the cloth was colored. A: 50 reciprocations or more B: 15 to 49 reciprocations C: 14 reciprocations or less.

[0111] (8) Adhesion to the second substrate and productivity of the film laminate From the film laminates obtained in each example and comparative example, sections with a width of 15 mm and a length of 50 mm were cut out. In an environment with a temperature of 25 °C and a humidity of 50% RH, the first substrate film and the second substrate were respectively sandwiched between the upper and lower chucks of a tensilon universal material testing machine RTG-1210 (manufactured by A&D Company), and a tensile test was performed under the condition of a test speed of 300 mm / min, and the load value at the first maximum point was measured. Each measurement was taken 3 times, and the average value was used as the initial peel strength. In addition, the sections after the tensile test were visually observed to identify the peel mode.

[0112] The film laminates obtained in each example and comparative example were allowed to stand at a temperature of 40 °C for 72 hours, i.e., aged. After that, the peel strength after aging was measured in the same manner, and the adhesion was evaluated. When the peel strength after aging was 2.0 N or more or the failure mode was film breakage, the adhesion was evaluated as good.

[0113] Also, the productivity was evaluated according to the following criteria based on the initial peel strength and the peel strength after aging. S: Both the initial peel strength and the peel strength after aging are 1.5 N or more and the difference is 1.0 N or less A: The initial peel strength is 0.8 or more and less than 1.5 N, and the peel strength after aging is 1.5 N or more B: The initial peel strength is 0.5 N or more and less than 0.8 N C: The initial peel strength is less than 0.5 N.

[0114] (9) Printing appearance In each of the examples and comparative examples, the leveling property was visually observed from the gloss and the presence or absence of ink bleeding in the solid part immediately after transferring the ink to the first base film A, and the printing appearance was evaluated according to the following criteria. S: The leveling property is particularly good A: The leveling property is good B: The leveling property is somewhat poor.

[0115] (10) Lamination appearance The film laminates obtained in each of the examples and comparative examples were visually observed to check for the presence or absence of delamination between layers, bubbles, etc.

[0116] Also, in each of the examples and comparative examples, using a reflection densitometer (“SpectroEye” manufactured by GretagMacbeth), the measurement mode was set to Status E. After the printing process and before the adhesive coating process, the reflection density of the solid part and the reflection density of the solid part of the obtained film laminate were measured respectively, and the presence or absence of reverse trapping was evaluated from the difference. In the measurement of the reflection density, coated paper was used as the standard with a reflection density of 0.

[0117] Based on these results, the lamination appearance was evaluated according to the following criteria. S: The color density change is less than 0.1, and no delamination between layers, bubbles, etc. are observed A: The color density change is 0.1 or more and less than 0.3, and almost no delamination between layers, bubbles, etc. are observed B: The color density change is 0.3 or more or delamination between layers, bubbles, etc. are observed.

[0118] The materials used in the examples and comparative examples are shown below.

[0119] <Base film> First base film A: A polyester film having a urethane bond-containing easy-adhesion layer with a thickness of 12 μm Second base film B: An unstretched polypropylene film “Trefan” (registered trademark) ZK207 (trade name) with a thickness of 50 μm, manufactured by Toray Film Processing Co., Ltd.

[0120] <Raw materials for ink, active energy ray curable adhesive, and solvent-free isocyanate curable adhesive> (Resin) Resin 1: 0.55 equivalents of glycidyl methacrylate was added to the carboxyl groups of a copolymer of 25% by mass methyl methacrylate / 25% by mass styrene / 50% by mass methacrylic acid to obtain a resin having ethylenically unsaturated double bonds and hydrophilic groups (hydroxyl groups and carboxyl groups), which was designated as Resin 1. The weight average molecular weight of the obtained Resin 1 was 34,000, the acid value was 105 mgKOH / g, and the iodine value was 2.0 mol / kg.

[0121] Resin 2: A resin that is a copolymer of 25% by mass methyl methacrylate / 25% by mass styrene / 50% by mass methacrylic acid was used as Resin 2. Resin 2 has neither hydrophilic groups nor ethylenically unsaturated double bonds. The weight average molecular weight of Resin 2 was 30,000.

[0122] (Urethane (meth)acrylate) Urethane acrylate 1: An oligomer having two ethylenically unsaturated double bonds at the ends, obtained from alicyclic diisocyanate (IPDI) / polyether polyol (polytetramethylene ether glycol) / 2-hydroxyethyl acrylate, was used as Urethane acrylate 1. The weight average molecular weight of Urethane acrylate 1 was 3,300.

[0123] Urethane acrylate 2: An oligomer having two ethylenically unsaturated double bonds at the ends, obtained from alicyclic diisocyanate (IPDI) / polyether polyol (polytetramethylene ether glycol) / 2-hydroxyethyl acrylate, was used as Urethane acrylate 2. The weight average molecular weight of Urethane acrylate 2 was 13,000.

[0124] (Monomer having ethylenically unsaturated double bond) Monomer 1: "Miramer" (registered trademark) M340 (manufactured by MIWON), a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate, was used. The hydroxyl value of Monomer 1 was 115 mgKOH / g.

[0125] Monomer 2: Tricyclodecane dimethanol diacrylate "Miramer" (registered trademark) M262 (manufactured by MIWON) was used. The hydroxyl value of Monomer 2 was 0 mgKOH / g.

[0126] (Other additives) Polymerization inhibitor: p-methoxyphenol (manufactured by Wako Pure Chemical Industries, Ltd.) Pigment: Seikashianin Blue 4920 (manufactured by Dainichi Seika Chemicals Co., Ltd.) Extender pigment: "Micro Ace" (registered trademark) P-8 (manufactured by Nippon Talc Co., Ltd.).

[0127] <Ink preparation> The above ink raw materials were weighed according to the following composition and passed through a three-roll mill "EXAKT" (registered trademark) M-80S (manufactured by EXAKT) 5 times at the setting "Gap 1" in the same apparatus to obtain printing ink.

[0128] (Ink A) Resin 1: 11.7 mass%, Monomer 1: 42.1 mass%, Monomer 2: 25.1 mass%, Polymerization inhibitor: 0.1 mass%, Pigment: 18.0 mass%, Extender pigment: 3.0 mass%.

[0129] (Ink B) Resin 1: 10.5 mass%, Urethane acrylate 1: 10.0 mass%, Monomer 1: 40.4 mass%, Monomer 2: 20.0 mass%, Polymerization inhibitor: 0.1 mass%, Pigment: 18.0 mass%, Extender pigment: 1.0 mass%.

[0130] (Ink C) Resin 1: 9.7 mass%, Monomer 1: 43.1 mass%, Monomer 2: 26.1 mass%, Polymerization inhibitor: 0.1 mass%, Pigment: 18.0 mass%, Extender pigment: 3.0 mass%.

[0131] (Ink D) Resin 2: 18.0% by mass, Monomer 1: 30.5% by mass, Monomer 2: 30.4% by mass, Polymerization inhibitor: 0.1% by mass, Pigment: 18.0% by mass, Extender pigment: 3.0% by mass.

[0132] [ Reference Example 1 ] Resin 1, Monomer 1, and Monomer 2 were mixed in the composition shown in Table 1, and the mixture was passed through a three-roll mill "EXAKT" (registered trademark) M-80S (manufactured by EXAKT) five times at a setting of "gap 1" to obtain an active energy ray-curable adhesive. Hereinafter, Example 1 shall be read as Reference Example 1.

[0133] Ink A was applied to the first substrate film A at a coating amount of 1.0 g / m using the offset printing unit of a center drum type printing machine "CI8" (manufactured by COMEXI). 2 The ink was transferred onto the ink film in such a way that the ink was transferred to the ink layer (printing process). Adhesive A was applied onto the ink film in an amount of 2.0 g / m using the flexographic printing unit of a center drum type printer "CI8" (manufactured by COMEXI). 2 (adhesive application step), and then a second base film B was laminated using a nip roll (lamination step). The resulting laminate was irradiated with electron beams from the first base film side using an electron beam irradiation unit under conditions of an acceleration voltage of 110 kV and an irradiation dose of 30 kGy (curing step), to obtain a film laminate in which first base film A / ink A / active energy ray-curable adhesive / second base film B were laminated in this order. The evaluation results of the resulting film laminate are shown in Table 1.

[0134] [ Reference Examples 2 to 5 ] Except for the change of the active energy ray curing adhesive composition and ink as shown in Table 1, Reference Example 1 A film laminate was produced in the same manner as in Example 1. The evaluation results of the obtained film laminate are shown in Table 1.

[0135] [ Reference Example 6 ] The composition of the active energy ray-curable adhesive and the ink were changed as shown in Table 1. Further, using an electron beam irradiation unit, except that the electron beam was irradiated from both sides of the first base film side and the second base film side under the conditions of an acceleration voltage of 110 kV and an irradiation dose of 30 kGy Reference Example 1 A film laminate was produced in the same manner as above. The evaluation results of the obtained film laminate are shown in Table 1.

[0136] [Comparative Example 1] Ink A was transferred to the first base film A in the same manner as in Example 1 (printing step), and electron beam irradiation was performed under the same conditions as in Example 1 (curing step) to obtain a laminate of the first base film A / Ink A cured film.

[0137] On the cured film of Ink A, a mixture of a solvent-containing adhesive ““TAKERAC” (registered trademark) A-969V / “TAKENATE” (registered trademark) A-5” manufactured by Mitsui Chemicals, Inc. in a mass ratio of 3 / 1 was applied using a bar coater so that the coating amount was 2.0 g / m 2 and dried at 80°C for 1 minute (adhesive coating step).

[0138] Thereafter, the second base film B was laminated using a hand roller (lamination step) to obtain a film laminate in which the first base film A / Ink A / adhesive / second base film B were laminated in this order. The evaluation results of the obtained film laminate are shown in Table 1.

[0139]

Table 1

[0140] [Example 7] Ink A was transferred to the base film A using an offset printing unit of a center drum type printing machine “CI8” (manufactured by COMEXI) so that the coating amount was 1.0 g / m 2 to form an ink coating film (printing step).

[0141] On the ink coating film, a mixture of an isocyanate-curing type adhesive ""Takelac"" (registered trademark) A-670B / ""Takenate"" (registered trademark) A-670A with a mass ratio of 5 / 10 was applied using a flexographic printing unit of a center drum type printing press ""CI8"" (manufactured by Comexi) at a coating amount of 2.0 g / m 2 so as to obtain (adhesive coating step), and under the same conditions as in Example 1, electron beams were irradiated from the side of the adhesive coating surface (curing step).

[0142] Subsequently, using a nip roll, the second base film B was laminated to obtain a film laminate. The evaluation results of the obtained laminate are shown in Table 2.

[0143] [Example 8] As an isocyanate-curing type resin, ""Takelac"" (registered trademark) A-670B / ""Takenate"" (registered trademark) A-670A (mass ratio 5 / 10) and Resin 1 were blended in the composition shown in Table 2 to obtain a solvent-free isocyanate-curing type adhesive. Specifically, first, 30 parts by mass of ""Takelac"" (registered trademark) A-670B and 10 parts by mass of Resin 1 were passed through 5 times at the setting of ""Gap 1"" in the same apparatus using a three-roll mill ""EXAKT"" (registered trademark) M-80S (manufactured by EXAKT) and mixed. Then, 60 parts by mass of ""Takenate"" (registered trademark) A-670A was added to 40 parts by mass of the obtained mixture, and the solvent-free isocyanate-curing type adhesive was prepared by manually shaking and stirring.

[0144] A film laminate was obtained in the same manner as in Example 7 except that the above solvent-free isocyanate-curing type adhesive was used. The evaluation results of the obtained film laminate are shown in Table 2.

[0145] [Examples 9, 10] As the isocyanate-curing resin, "Takelac" (registered trademark) A-670B / "Takonate" (registered trademark) A-670A (mass ratio 5 / 10) and urethane acrylate 1 or 2 were blended in the composition shown in Table 2 to obtain a solvent-free isocyanate-curing adhesive. Specifically, 10 parts by mass of urethane acrylate 1 or 2 was added to 90 parts by mass of a mixture of "Takelac" (registered trademark) A-670B / "Takonate" (registered trademark) A-670A with a mass ratio of 5 / 10, and shaken and stirred manually to obtain a solvent-free isocyanate-curing adhesive.

[0146] A film laminate was obtained in the same manner as in Example 7 except that the above solvent-free isocyanate-curing adhesive was used. The evaluation results of the obtained film laminate are shown in Table 2.

[0147] [Comparative Example 2] In the same manner as in Example 1, Ink A was transferred to the first base film A (printing step), and electron beam irradiation was performed under the same conditions as in Example 1 (curing step) to obtain a laminate of the first base film A / Ink A cured film.

[0148] On the cured film of Ink A, a mixture of "Takelac" (registered trademark) A-244B / "Takonate" (registered trademark) A-244A, a solvent-free isocyanate-curing adhesive manufactured by Mitsui Chemicals, Inc., with a mass ratio of 5 / 10, was applied using a bar coater so that the coating amount was 2.0 g / m 2 (adhesive coating step).

[0149] Thereafter, the second base film B was laminated using a hand roller (lamination step) to obtain a film laminate in which the first base film A / Ink A / adhesive / second base film B were laminated in this order. The evaluation results of the obtained film laminate are shown in Table 2.

[0150]

Table 2

Explanation of Symbols

[0151] 1: First base film 2: Offset printing unit 3: Flexographic printing unit 4: Nip roll 5: Second base material 6: Electron beam irradiation device

Claims

1. A method for manufacturing a film laminate, which in-line performs a printing step of applying an active energy ray-curable printing ink, an adhesive application step of applying an adhesive, and a lamination step of laminating a second substrate to a first substrate film made of at least a plastic film, in this order, further comprising a curing step of irradiating active energy rays to cure the active energy ray-curable printing ink, at least after the adhesive application step, wherein the adhesive in the adhesive application step is a solventless isocyanate-curable adhesive, and having the curing step before the lamination step.

2. The viscosity α of the active energy ray-curable printing ink at 30°C and a shear rate of 300 s －１ The ratio β2 / α of the viscosity β2 of the solventless isocyanate-curable adhesive at 30°C and a shear rate of 300 s －１ to the viscosity α is 0.01 or more and 0.50 or less, and the method for producing a film laminate according to claim 1.

3. The viscosity β2 of the solvent-free isocyanate-curing adhesive at a temperature of 30°C and a shear rate of 300 s －１ is 1 Pa·s or more and 20 Pa·s or less, and the viscosity β2' of the solvent-free isocyanate-curing adhesive at a temperature of 80°C and a shear rate of 300 s －１ is 0.05 Pa·s or more and 5 Pa·s or less. The method for producing a film laminate according to claim 1 or 2

4. The viscosity α of the active energy ray-curable printing ink at a temperature of 30°C and a shear rate of 300 s －１ is 10 Pa·s or more and 40 Pa·s or less, and the method for producing a film laminate according to any one of claims 1 to 3.

5. The method for manufacturing a film laminate according to any one of Claims 1 to 4, wherein the solventless isocyanate-curable adhesive contains an isocyanate-curable resin and a compound having an ethylenically unsaturated double bond, and the total content of the compound having an ethylenically unsaturated double bond is 1% by mass or more and 30% by mass or less.

6. The method for manufacturing a film laminate according to any one of Claims 1 to 5, wherein the active energy ray-curable printing ink contains a resin and a compound having an ethylenically unsaturated double bond.

7. The method for manufacturing a film laminate according to Claim 5 or 6, wherein the compound having an ethylenically unsaturated double bond contains urethane (meth)acrylate.

8. The method for manufacturing a film laminate according to Claim 7, wherein the weight average molecular weight Mw of the urethane (meth)acrylate is 500 to 10,000.

9. The method for manufacturing a film laminate according to any one of Claims 1 to 8, wherein the active energy rays in the curing step are electron beams.

Images