Printed materials, print media, and packaging

Abstract

The present invention provides a printed material in which the adhesion between the base material layer and the ink layer is enhanced, a printing medium used for the printed material, and a packaging body using the printed material. [Solution] A printed material 101 that has been offset printed using an active energy ray curable ink containing an active energy ray curable resin, comprising an ink layer 4 containing an active energy ray curable ink, a substrate layer 1 having affinity with the active energy ray curable resin, and a modifying layer 3 that modifies the ink.

Description

Technical Field

[0001] The present invention relates to a printed matter obtained by offset printing with an active energy ray-curable ink, a printing medium suitable for offset printing with an active energy ray-curable ink, and a package formed by the printed matter.

Background Art

[0002] In a packaging bag for packaging foods and the like, printing or the like may be applied to the inner or outer surface of a base material layer that forms the outermost layer for decoration. Conventionally, this type of printing has mainly been by the gravure method (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The packaging bag described in Patent Document 1 is manufactured from a laminate having a film base material layer, a printing layer, and a laminate layer. Among these, the printing layer is formed by gravure printing, and as the ink composition used at that time, one containing an organic solvent such as esters and a polyurethane-urea resin is used.

[0005] As described above, in conventional packaging bags including Patent Document 1, organic solvents have been used in gravure printing. However, in recent years, in consideration of the environment, a printing method that does not use organic solvents has been desired. However, when an organic solvent is replaced with, for example, an aqueous solvent in gravure printing, problems such as a decrease in print quality resulting in design constraints, a decrease in the physical properties of the printing layer, and a decrease in productivity due to a longer drying time occur.

[0006] To solve these problems, it is conceivable to replace gravure printing with offset printing that does not use organic solvents, for example, with active energy ray curing inks. However, conventional offset printing is a printing method that generally uses rigid paper (for example, cardboard) as the printing substrate, and therefore the formulation is not designed to handle relatively thin substrate layers, which may result in insufficient adhesion between the substrate layer and the ink used in offset printing.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a printed material in which the adhesion between the base material layer and the ink layer is enhanced, a printing medium used for the printed material, and a packaging body using the printed material. [Means for solving the problem]

[0008] The characteristic configuration of the printed material according to the present invention, which solves the above problems, is A printed material that has been offset printed using an active energy ray curable ink containing an active energy ray curable resin, An ink layer containing the aforementioned active energy ray curable ink, A substrate layer having affinity for the active energy ray curable resin, A modifying layer that modifies the aforementioned ink layer and The goal is to provide for it.

[0009] With this configuration, the modified layer modifies the ink layer, i.e., the ink used in offset printing with active energy ray-curable ink. Combined with the fact that the substrate layer has affinity for active energy ray-curable resin, this improves the adhesion between the substrate layer and the ink layer.

[0010] In the printed material according to the present invention, The modified layer preferably contains a urethane-based resin.

[0011] According to this configuration, the inclusion of a urethane-based resin in the modified layer can further improve the adhesion between the substrate layer and the ink layer.

[0012] In the printed material according to the present invention, Preferably, the modified layer further comprises a sealant layer on the side opposite to the ink layer.

[0013] According to the printed material with this configuration, if a sealant layer is provided on the opposite side of the modified layer from the ink layer, the modified layer can also function as an adhesive layer that bonds the substrate layer and the sealant layer.

[0014] In the printed material according to the present invention, The modified layer preferably contains an acrylic resin.

[0015] According to the printed material with this configuration, the modified layer, by containing an acrylic resin, can also function as a surface protective layer that protects the surface of the ink layer.

[0016] In the printed material according to the present invention, It is preferable that the substrate layer further comprises a sealant layer via an adhesive layer on the side opposite to the ink layer.

[0017] With this configuration, it is possible to protect the surface of the ink layer on one side with a modified layer, while allowing the sealant layer on the other side to be subjected to heat sealing.

[0018] In the printed material according to the present invention, It is preferable that the device is irradiated with active energy rays.

[0019] With this configuration, when activated energy rays are irradiated, the adhesion between the substrate layer and the ink layer is improved, and a printed material with improved strength and flexibility can be obtained.

[0020] The characteristic configuration of the printing medium according to the present invention, which solves the above problems, is as follows: A printing medium suitable for offset printing using an active energy ray curable ink containing an active energy ray curable resin, The substrate layer comprises at least an active energy ray curable resin having affinity for it. The substrate layer is configured to improve its adhesion to the active energy ray-curable resin by irradiation with active energy rays.

[0021] According to this configuration, by including a substrate layer having affinity for at least the active energy ray-curable resin, the adhesion of the active energy ray-curable resin (which is the main component of the ink layer) to the substrate layer can be maintained at a high level even after the active energy ray-curable resin has hardened due to irradiation with active energy rays. Furthermore, it is possible to achieve both strength and flexibility in the printing medium.

[0022] In the printing medium according to the present invention, The activated energy beam preferably has an accelerating voltage of 120 kV or less and an irradiation dose of 25 to 50 kGy.

[0023] This configuration of the printing medium allows for improved adhesion of the active energy ray-curable resin to the substrate layer.

[0024] Another characteristic configuration of the printing medium according to the present invention, which solves the above problem, is: A printing medium suitable for offset printing using an active energy ray curable ink containing an active energy ray curable resin, The substrate layer comprises at least an active energy ray curable resin having affinity for it. The substrate layer, when measured by micro-angle incident X-ray diffraction using a zero-dimensional detector with the 2θ method using CuKα rays, has an X-ray diffraction pattern in which the intensity of the amorphous peak is I0, the intensity of the first peak (110) plane is I1, and the intensity of the second peak (200) plane is I2, is given by the following equation (1): R = (I1+I2) / I0 ···(1) The key difference is that the intensity ratio R, represented by [formula], is between 2 and 20.

[0025] With this printing medium configuration, since the substrate layer is a crystalline material irradiated with active energy rays having a specific X-ray diffraction pattern, the adhesion between the substrate layer and the active energy ray curable resin (which is the main component of the ink layer) can be improved. Furthermore, the strength of the substrate layer, such as its puncture resistance, can be increased, as can its flexibility.

[0026] In the printing medium according to the present invention, Preferably, the substrate layer is configured to improve its adhesion to the active energy ray-curable resin by irradiation with an active energy ray having an acceleration voltage of 120 kV or less and an irradiation dose of 25 to 50 kGy.

[0027] This printing medium configuration allows for improved adhesion of the active energy ray-curable resin to the substrate layer, as well as increased strength of the substrate layer, such as flexural resistance and puncture resistance, and improved flexibility.

[0028] In the printing medium according to the present invention, Preferably, the active energy ray curable resin is further modified by a modified layer.

[0029] According to the printing medium with this configuration, by further including a modified layer, when offset printing is performed on the printing medium using an active energy ray-curable ink, the ink layer, i.e., the ink used for offset printing with an active energy ray-curable ink, is modified. Combined with the fact that the substrate layer has affinity for active energy ray-curable resin, this improves the adhesion between the substrate layer and the ink layer.

[0030] In the printing medium according to the present invention, The modified layer preferably contains a urethane resin or an acrylic resin.

[0031] This printing medium configuration allows for improved adhesion between the substrate layer and the ink layer, as well as protection of the ink layer's surface.

[0032] Another characteristic configuration of the packaging according to the present invention, which solves the above problem, is: The fact that it is formed by the aforementioned printed material or printing medium.

[0033] With this packaging configuration, the adhesion between the substrate layer and the active energy ray-curable resin is enhanced because it is formed using the above-mentioned printed material or printing medium, and peeling or detachment of the active energy ray-curable resin is suppressed. [Brief explanation of the drawing]

[0034] [Figure 1] Figure 1 is a schematic cross-sectional view showing the layer structure of a printed material according to the first embodiment of the present invention. [Figure 2] Figure 2 is a schematic diagram illustrating an example of a printing method used in the present invention. [Figure 3] Figure 3 is a schematic cross-sectional view showing the layer structure of a printed material according to a second embodiment of the present invention. [Figure 4] Figure 4 is a schematic cross-sectional view showing the layer structure of a printed material according to the third embodiment of the present invention. [Figure 5] Figure 5 is a schematic cross-sectional view showing the layer structure of a printed material according to the fourth embodiment of the present invention. [Figure 6] Figure 6 is a schematic cross-sectional view showing the layer structure of a printed material according to the fifth embodiment of the present invention. [Figure 7] Figure 7 is a schematic cross-sectional view showing the layer structure of a printed material according to the sixth embodiment of the present invention. [Figure 8] Figure 8 is a schematic cross-sectional view showing the layer structure of a printed material according to the seventh embodiment of the present invention. [Figure 9] Figure 9 is a schematic cross-sectional view showing the layer structure of a printed material according to the eighth embodiment of the present invention. [Figure 10] Figure 10 is a schematic cross-sectional view showing the layer structure of a printed material according to the ninth embodiment of the present invention. [Figure 11] Figure 11 is a schematic cross-sectional view showing the layer structure of a printed material according to the tenth embodiment of the present invention. [Figure 12]Figure 12 is a schematic cross-sectional view showing the layer structure of a printed material according to the 11th embodiment of the present invention. [Figure 13] Figure 13 is a schematic diagram showing an example of a packaged product equipped with a packaging body according to the 13th embodiment of the present invention. [Figure 14] Figure 14 is a schematic diagram showing the setup of the sample during crystallinity evaluation. [Figure 15] Figure 15 is a graph showing the relationship between EB irradiation energy and penetration intensity. [Figure 16] Figure 16 is a graph showing the dependence of the X-ray penetration depth from the PE surface on the angle of incidence. [Figure 17] Figure 17 shows the X-ray diffraction profile of HDPE measured under specified conditions. [Figure 18] Figure 18 shows the X-ray diffraction profiles of HDPE and LLDPE measured under specified conditions. [Figure 19] Figure 19 is a graph showing the relationship between EB irradiation energy and the peak intensity of the X-ray diffraction profile. [Figure 20] Figure 20 is a graph showing the relationship between EB irradiation energy and the peak intensity of the X-ray diffraction profile. [Figure 21] Figure 21 is a table summarizing the relationship between EB irradiation energy and X-ray diffraction profile. [Figure 22] Figure 22 is a schematic diagram showing the crystalline system of polyethylene and the crystal planes and unit cell observed by X-ray diffraction measurements. [Figure 23] Figure 23 is a graph showing the relationship between EB irradiation energy and the peak intensity of HDPE in the X-ray diffraction profile. [Figure 24] Figure 24 is a graph showing the relationship between EB irradiation energy and the peak intensity of HDPE in the X-ray diffraction profile. [Figure 25] Figure 25 is a graph showing the relationship between EB irradiation energy and the peak intensity of LLDPE in the X-ray diffraction profile. [Figure 26]Figure 26 is a graph showing the relationship between EB irradiation energy and the peak intensity of LLDPE in the X-ray diffraction profile. [Figure 27] Figure 27 is a table summarizing the trend of crystallinity changes due to EB irradiation energy. [Figure 28] Figure 28 is a schematic diagram illustrating the electron beam crosslinking mechanism of polyethylene. [Figure 29] Figure 29 is a photograph showing the shape of the film after the gel fraction measurement. [Figure 30] Figure 30 is a photograph showing the shape of the film after the gel fraction measurement. [Figure 31] Figure 31 is a graph showing the relationship between EB irradiation dose and gel fraction. [Figure 32] Figure 32 is a graph showing the dissolution contrast. [Figure 33] Figure 33 is a schematic diagram illustrating single-sided and double-sided EB irradiation. [Figure 34] Figure 34 is a graph showing the relationship between EB irradiation dose and gel fraction in single-sided / double-sided irradiation of LLDPE. [Figure 35] Figure 35 is a graph showing the dissolution contrast of LLDPE under single-sided / double-sided irradiation. [Figure 36] Figure 36 is a graph showing the dissolution contrast in single-sided and double-sided irradiation of HDPE. [Figure 37] Figure 37 is a table summarizing the findings on gel fraction. [Figure 38] Figure 38 is a graph showing the DSC / DDSC curve for LLDPE. [Figure 39] Figure 39 is a graph showing the DSC curve for LLDPE. [Figure 40] Figure 40 is a graph showing the relationship between EB irradiation dose and the melting point and enthalpy of melting of LLDPE. [Figure 41] Figure 41 is a graph showing the DSC curve for HDPE. [Figure 42]Figure 42 is a graph showing the relationship between EB irradiation dose and the melting point and enthalpy of melting of HDPE. [Figure 43] Figure 43 is a graph showing the relationship between EB irradiation dose and the crystallinity of PE. [Modes for carrying out the invention]

[0035] The following describes embodiments of the printed material and printing medium according to the present invention. However, the present invention is not intended to be limited to the embodiments, examples, and drawings described below. Note that the layer configurations shown in each figure do not strictly represent the actual structure, shape, dimensions, thickness ratios, and relative sizes of each layer.

[0036] [Printed material] When gravure printing is replaced with offset printing, the adhesion between the ink and the substrate layer (the printing medium) tends to decrease. For example, if an active energy ray-curable resin is used as the curable resin in the ink, and the ink is offset printed onto the substrate layer and then irradiated with active energy rays, the ink layer becomes relatively hard, resulting in reduced adhesion between the ink layer and the substrate layer compared to gravure printing. Reduced adhesion between the ink layer and the substrate layer increases the occurrence of defective products and lowers the yield in the printing process. In addition, during transportation of printed materials, the ink layer may peel off due to impact, etc. Ink peeling is particularly likely to occur when the substrate layer is flexible.

[0037] One possible solution to these problems is to increase the concentration of the active energy ray-curable resin in the ink to improve ink adhesion. However, increasing the concentration of the active energy ray-curable resin in the ink increases its viscosity, which can reduce its fluidity, dispersibility, and leveling properties, potentially lowering the accuracy (reproducibility) of the print. Poor print reproducibility leads to poor legibility, which is particularly noticeable in complex images and characters with many strokes. Thus, there is a trade-off between adhesion and print reproducibility, and simply improving the ink's components makes it difficult to improve adhesion while suppressing a decrease in print reproducibility.

[0038] Based on these findings, the inventors conducted diligent research and discovered that by providing a modifying layer on top of the cured ink layer on the substrate layer, which modifies the ink constituting the ink layer, it is possible to improve adhesion while suppressing a decrease in print reproducibility, without relying on the concentration of the active energy ray curable resin contained in the ink.

[0039] The mechanism by which the present invention enhances ink adhesion is not entirely clear, but it can be inferred, for example, as follows: In offset printing, due to the printing method and the leveling properties of the ink, the surface of the ink layer is not always smooth. As a result, when the ink particles harden, fine gaps exist between the ink particles in the ink layer. In this state, if a liquid ink modifier is applied to the ink layer after or before it hardens, the ink modifier penetrates between the ink particles, and some of the ink modifier reaches the substrate layer. In the process of the ink modifier hardening to form a modified layer, the ink modifier enhances the adhesion between the ink particles and also enhances the adhesion between the ink particles and the substrate layer, thereby increasing the durability of the ink layer.

[0040] Incidentally, in offset printing, ink is pulled off during the transfer from the printing plate to the blanket, causing stringing. When stringing occurs in the ink, tiny bubbles can form within the ink. These tiny bubbles may reduce the adhesion of the ink layer. In particular, when printed materials are used in retort packaging, the tiny bubbles in the ink expand during heating, resulting in a significant decrease in the adhesion of the ink layer. However, it has been found that when an ink modifier penetrates these bubbles, the adhesion between the ink layer and the substrate layer surprisingly increases.

[0041] This unique phenomenon is specific to offset printing, regardless of whether it is a wet or wet method. In particular, in the wet method, since printing is performed with some of the dampening solution contained in the ink, when the dampening solution evaporates due to irradiation with active energy rays, tiny voids (micropores) are formed in the ink. At this time, the ink modifier penetrates into the micropores in the ink by capillary action. It is presumed that this increases the adhesion between ink particles, and as a result, the adhesion between the ink layer and the substrate layer is improved.

[0042] Based on the above findings, the inventors have created a printed material that improves the adhesion between the substrate layer and the ink layer, as well as its strength and flexibility. The first to twelfth embodiments of the printed material of the present invention will now be described. It should be noted that the printed material of the present invention is obtained by irradiation with active energy rays, but as mentioned above, the mechanism by which irradiation with active energy rays improves the adhesion, strength, and flexibility of the ink to the substrate layer is not fully understood. Therefore, it may not be practical to completely specify the structure of the printed material of the present invention as a physical object.

[0043] [First Embodiment] Figure 1 is a schematic cross-sectional view showing the layer structure of a printed material according to the first embodiment of the present invention.

[0044] The printed material 101 shown in Figure 1 is a laminate formed by reverse offset printing. The printed material 101 comprises, from the top (surface side), a base layer 1 having affinity for an active energy ray curable resin, an ink layer 4 containing an active energy ray curable resin, and a modified layer 3 that modifies the ink layer 4.

[0045] Active energy rays are energy rays capable of generating radical-like active species, and examples include electromagnetic waves such as X-rays and gamma rays, particle beams such as electron beams (EB), proton beams, and alpha rays, and non-ionizing radiation such as microwaves and ultraviolet rays. Of these, electron beams (EB) have a higher activity energy (energy that generates radical-like active species) than ultraviolet rays (UV), yet are less easily absorbed by pigments contained in inks, and are therefore preferably used in offset printing with active energy ray-curable inks. Generally, when curing resins (monomers) by irradiation with ultraviolet rays (UV), a polymerization initiator is required. However, when a polymerization initiator is included, there is a risk that the polymerization initiator that was not used in the curing reaction may remain in the cured product. Also, even if a polymerization initiator is included, the resin may not be sufficiently cured, and unreacted residual monomers may remain. Considering these factors, it is preferable that the active energy ray is one that does not contain ultraviolet rays (i.e., something other than ultraviolet rays). Furthermore, it is even more preferable that the active energy ray is one with higher activity energy than ultraviolet rays, as this eliminates the need for a polymerization initiator.

[0046] <Ink layer> The ink layer (printing layer) 4 contains an active energy ray-curable ink (hereinafter also referred to as "ink") which contains an active energy ray-curable resin. The active energy ray-curable resin is the main component of the ink layer (printing layer) 4. Here, "main component" means that it is present in an amount of 50% by weight or more, preferably 70% by weight or more, and more preferably 90% by weight or more. The active energy ray-curable resin has the property of crosslinking (curing) between molecules of the active energy ray-curable resin (crosslinking property) or the property of chemically bonding (curing) the active energy ray-curable resin with other resins, etc. (curability property) by generating radical active species in the molecule upon irradiation with active energy rays, and by the formation of new bonds between the active species.

[0047] As mentioned above, it is preferable that the active energy ray curable resin is a resin that hardens with active energy rays that do not contain ultraviolet light, and more preferably a resin that hardens with active energy rays higher than ultraviolet light. By selecting these resins as active energy ray curable resins, polymerization initiators are not required in the reaction of the active energy ray curable resin, and the residue of polymerization initiators and residual monomers after hardening can be reduced, which is advantageous from a hygienic standpoint. In addition, when curing the resin by irradiation with active energy rays, if ultraviolet light is used, the pot life (the time it takes for the active energy ray curable resin to harden during storage (i.e., the time it remains unhardened)) is shortened, and the concentration and viscosity of the active energy ray curable resin may change as it hardens over time. Furthermore, because ultraviolet light has low transmittance to active energy ray curable resins, hardening progresses on the surface (irradiated surface) side where ultraviolet light is irradiated in the thickness direction, while hardening does not progress as you move away from the irradiated surface, creating a hardening gradient and making it difficult to harden the active energy ray curable resin uniformly. However, as described above, by using active energy rays that do not contain ultraviolet light, or active energy rays with higher activity energy than ultraviolet light (for example, electron beams), it is possible to cure active energy ray-curable resins instantaneously (more quickly than when using ultraviolet light) without the need to incorporate polymerization initiators. As a result, the pot life is significantly extended, and the active energy rays can penetrate deeper into the active energy ray-curable resin than ultraviolet light. Consequently, even when the active energy ray-curable resin is relatively thick, it can be cured more uniformly (with a smaller gradient) than when using ultraviolet light. Furthermore, because the active energy rays can penetrate the entire resin in the thickness direction, drying defects can be reduced even when the active energy ray-curable resin is relatively thick.

[0048] The ink, which is the raw material for the ink layer 4, contains the above-mentioned active energy ray-curable resin that hardens upon irradiation with active energy rays, and may further contain a pigment. When the active energy ray-curable resin hardens upon irradiation with active energy rays, internal stress is generated due to hardening shrinkage, which can be a factor in reducing the adhesion between the ink layer 4 and the substrate layer 1. However, in this embodiment, the modified layer 3 is provided, and the modified layer 3 acts as a buffer layer, suppressing the decrease in adhesion between the ink layer 4 and the substrate layer 1. Furthermore, the modified layer 3 modifies the ink contained in the ink layer 4, thereby improving the adhesion between the ink layer 4 and the substrate layer 1.

[0049] Examples of active energy ray curable resins, which are one of the raw materials for the ink layer 4, include resin compositions having (a) a resin having hydrophilic groups and ethylene unsaturated groups (referred to as "resin (a)"), (b) a polyfunctional (meth)acrylate having hydrophilic groups (referred to as "polyfunctional (meth)acrylate (b)"), and (c) a difunctional (meth)acrylate having hydrophobic properties (referred to as "difunctional (meth)acrylate (c)"). Note that "(meth)acrylate" means "acrylate and / or methacrylate".

[0050] (Resin (a)) Resin (a) has hydrophilic groups. Examples of hydrophilic groups include hydroxyl groups, amino groups, mercapto groups, carboxyl groups, sulfo groups, and phosphate groups. Among these, carboxyl groups and hydroxyl groups are preferred because they provide good dispersibility of pigments in the ink.

[0051] Resin (a) has ethylenically unsaturated groups. The iodine value of the ethylenically unsaturated groups is preferably 0.5 mol / kg or more, more preferably 1.0 mol / kg or more, and even more preferably 1.5 mol / kg or more. By setting the iodine value of the ethylenically unsaturated groups to be above the lower limit, good curing sensitivity by irradiation with active energy rays can be obtained. The iodine value of the ethylenically unsaturated groups is preferably 3.0 mol / kg or less, more preferably 2.5 mol / kg or less, and even more preferably 2.2 mol / kg or less. By setting the iodine value of the ethylenically unsaturated groups to be below the upper limit, the storage stability of the ink is improved. The iodine value is measured in accordance with the method described in section 6.0 of the test method of JIS K 0070:1992.

[0052] A resin (a) having hydrophilic groups and ethylenically unsaturated groups can be obtained, for example, by the following method. Specifically, a resin (a) having hydrophilic groups and ethylenically unsaturated groups can be obtained by adding ethylenically unsaturated compounds having glycidyl groups or isocyanate groups, acrylic acid chloride, methacrylate chloride, allyl chloride, etc., to active hydrogen-containing groups such as mercapto groups, amino groups, hydroxyl groups, carboxyl groups, etc., in a resin having hydrophilic groups. However, the method for producing resin (a) is not limited to this.

[0053] Examples of ethylenically unsaturated compounds containing a glycidyl group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, glycidyl crotonic acid, and glycidyl isocrotonic acid.

[0054] Examples of ethylenically unsaturated compounds having an isocyanate group include acryloyl isocyanate, methacryloyl isocyanate, acryloylethyl isocyanate, and methacryloylethyl isocyanate.

[0055] The acid value of resin (a) is preferably 30 mg KOH / g or higher, more preferably 60 mg KOH / g or higher, and even more preferably 75 mg KOH / g or higher. Setting the acid value above the lower limit improves the pigment dispersibility of the ink. The acid value of resin (a) is preferably 250 mg KOH / g or lower, more preferably 200 mg KOH / g or lower, and even more preferably 150 mg KOH / g or lower. Setting the acid value below the upper limit maintains appropriate fluidity of the ink. The acid value of resin (a) is measured in accordance with the neutralization titration method described in section 3.1 of JIS K 0070:1992.

[0056] The hydroxyl value of resin (a) is preferably 30 mg KOH / g or higher, more preferably 75 mg KOH / g or higher, and even more preferably 100 mg KOH / g or higher. Setting the hydroxyl value of resin (a) above the lower limit improves the pigment dispersibility of the ink. The hydroxyl value of resin (a) is preferably 350 mg KOH / g or lower, more preferably 275 mg KOH / g or lower, and even more preferably 250 mg KOH / g or lower. Setting the hydroxyl value of resin (a) below the upper limit ensures proper ink fluidity. The hydroxyl value of resin (a) is measured in accordance with the neutralization titration method described in section 7.1 of JIS K 0070:1992.

[0057] The weight-average molecular weight (Mw) of resin (a) is preferably 5,000 or more, more preferably 15,000 or more, and even more preferably 20,000 or more. Setting the weight-average molecular weight (Mw) of resin (a) above the lower limit increases the viscosity of the ink under high shear. The weight-average molecular weight (Mw) of resin (a) is preferably 100,000 or less, more preferably 75,000 or less, and even more preferably 50,000 or less. Setting the weight-average molecular weight (Mw) of resin (a) below the upper limit increases the fluidity of the ink. The weight-average molecular weight (Mw) of resin (a) is measured in polystyrene equivalent using gel permeation chromatography (GPC).

[0058] The content of resin (a) in the ink is preferably 3 to 50% by mass, more preferably 4 to 35% by mass, even more preferably 5 to 20% by mass, and particularly preferably 10 to 15% by mass. By setting the content within the above range, the pigment dispersibility of the ink can be made appropriate.

[0059] Examples of resin (a) include acrylic resins, styrene-acrylic resins, styrene-maleic acid resins, rosin-modified maleic acid resins, rosin-modified acrylic resins, epoxy resins, polyester resins, polyurethane resins, and phenolic resins. Of these, acrylic resins, styrene-acrylic resins, and styrene-maleic acid resins are preferred in terms of ease of monomer acquisition, low cost, ease of synthesis, compatibility with other components in the ink, and pigment dispersibility. Resin (a) may be used alone or as a mixture of two or more types.

[0060] More preferred specific examples of resin (a) include (meth)acrylic acid copolymer, (meth)acrylic acid-(meth)acrylic acid ester copolymer, styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer, styrene-maleic acid copolymer, styrene-maleic acid-(meth)acrylic acid copolymer, styrene-maleic acid-(meth)acrylic acid ester copolymer, and the like.

[0061] (Polyfunctional (meth)acrylate(b)) The hydrophilic groups contained in the polyfunctional (meth)acrylate (b) help to disperse and stabilize the pigment in the ink, thereby suppressing an excessive decrease in ink viscosity even under high shear conditions. Examples of hydrophilic groups include ethylene oxide skeletons, carboxyl groups, hydroxyl groups, amino groups, and sulfonic acid groups. Of these, hydroxyl groups, which have particularly high hydrophilicity, are preferred.

[0062] The polyfunctional (meth)acrylate (b) is preferably a urethane acrylate containing urethane groups. When the content of polyfunctional (meth)acrylate (b) in the ink increases, or when its molecular weight increases, the viscosity of the ink increases and its fluidity decreases. Therefore, by appropriately setting the content of urethane groups in the urethane acrylate, the cohesive force of the ink can be increased, and as a result, the adhesion of the ink layer 4 is improved. By appropriately setting the content of urethane groups in the urethane acrylate, peeling of the ink layer 4 is suppressed, especially during hot water treatment, and the durability of the ink layer 4 is improved. The urethane bonding group has a relatively high rigidity structure (hard segment), which can suppress entanglement of molecular chains. As a result, the increase in ink viscosity can be suppressed, and the cohesive force of the ink printed (coated) on the substrate layer 1 can be increased. In this way, it is presumed that the adhesion between the ink layer 4 and the substrate layer 1 is improved. Furthermore, it is presumed that the polyfunctional (meth)acrylate (b) contains urethane acrylate, which crosslinks with radical species generated from the unsaturated groups of resin (a) upon irradiation with active energy rays, and that this strong covalent bond can cure the ink particles. It is preferable to set the proportion of urethane bonds in the polyfunctional (meth)acrylate (b) to 0.05% by mass or less in the ink. The proportion of urethane bonds is measured by nuclear magnetic resonance (NMR).

[0063] The content of polyfunctional (meth)acrylate (b) in the ink is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more. By setting the content of polyfunctional (meth)acrylate (b) above the lower limit above, the adhesion of the ink layer 4 and the fluidity of the ink are improved. The content of polyfunctional (meth)acrylate (b) in the ink is preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass or less, and particularly preferably 50% by mass or less. By setting the content of polyfunctional (meth)acrylate (b) below the upper limit above, the increase in viscosity of the ink due to intermolecular forces between polar groups is suppressed, and the fluidity is improved.

[0064] The hydroxyl value of polyfunctional (meth)acrylate (b) is preferably 30 mg KOH / g or higher, more preferably 75 mg KOH / g or higher, and even more preferably 100 mg KOH / g or higher. Setting the hydroxyl value of polyfunctional (meth)acrylate (b) above the lower limit above improves the fluidity of the ink. The hydroxyl value of polyfunctional (meth)acrylate (b) is preferably 200 mg KOH / g or less, more preferably 180 mg KOH / g or less, and even more preferably 160 mg KOH / g or less. Setting the hydroxyl value of polyfunctional (meth)acrylate (b) below the upper limit above suppresses the increase in ink viscosity due to intermolecular forces between polar groups, and improves the fluidity of the ink.

[0065] The weight-average molecular weight (Mw) of the polyfunctional (meth)acrylate (b) is preferably 100 or more, more preferably 150 or more, and even more preferably 200 or more. Setting the weight-average molecular weight (Mw) above the lower limit above makes the ink coating more flexible and improves the adhesion of the ink layer 4. The weight-average molecular weight (Mw) of the polyfunctional (meth)acrylate (b) is preferably 1,000 or less, more preferably 700 or less, and even more preferably 500 or less. Setting the weight-average molecular weight (Mw) below the upper limit above suppresses the increase in ink viscosity and improves the ink's fluidity. The weight-average molecular weight (Mw) can be measured in polystyrene equivalent using gel permeation chromatography (GPC). Furthermore, if the ink contains multiple types of polyfunctional (meth)acrylate (b), the sum of their average values ​​is used as the weight-average molecular weight (Mw) of the polyfunctional (meth)acrylate (b) in this invention.

[0066] The polyfunctional (meth)acrylate (b) preferably has a hydroxyl group. Examples of polyfunctional (meth)acrylates (b) having a hydroxyl group include poly(meth)acrylates of polyhydric alcohols such as trimethylolpropane, glycerin, pentaerythritol, diglycerin, ditrimethylolpropane, isocyanuric acid, and dipentaerythritol, and alkylene oxide adducts thereof. Specifically, examples include trimethylolpropane di(meth)acrylate, glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, diglycerin di(meth)acrylate, diglycerin tri(meth)acrylate, ditrimethylolpropane di(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, etc. Furthermore, examples include ethylene oxide adducts, propylene oxide adducts, butylene oxide adducts, tetramethylene oxide adducts, etc. of these compounds. Of these, pentaerythritol tri(meth)acrylate, diglycerin tri(meth)acrylate, and ditrimethylolpropane tri(meth)acrylate are preferred because they can improve the pigment dispersibility and fluidity of the ink. The polyfunctional (meth)acrylate (b) may be used alone or in mixture of two or more types. When the polyfunctional (meth)acrylate (b) contains the same type of functional group as the resin in the modified layer 3, for example, when the polyfunctional (meth)acrylate (b) in the ink contains a urethane group and the modified layer 3 contains a urethane-based resin having a urethane group, the affinity between the two is increased, and the adhesion of the ink layer 4 to the substrate layer 1 is further improved.

[0067] (2-functional (meth)acrylate(c)) The difunctional (meth)acrylate (c) has a hydroxyl value of 5 mgKOH / g or less and exhibits hydrophobicity. The difunctional (meth)acrylate (c) preferably has a chain-like aliphatic skeleton with 8 to 18 carbon atoms. The chain-like aliphatic skeleton may be a linear skeleton or a branched skeleton, and may consist of saturated or unsaturated bonds. Since the difunctional (meth)acrylate (c) is moderately compatible with resin (a) and polyfunctional (meth)acrylate (b), entanglement of molecular chains in the ink is suppressed. As a result, stringiness (tendency to pull) when the ink is transferred is suppressed, and consequently, ink transferability is improved. In addition, the inclusion of the difunctional (meth)acrylate (c) in the ink reduces the surface tension of the ink and improves wettability to the substrate layer 1, thus improving ink transferability. Here, ink transferability refers to the property of how easily ink is transferred from rubber (metal) roll to rubber (metal) roll, from rubber (metal) roll to printing plate, from printing plate to blanket, and from blanket to substrate layer. Ink transferability is evaluated by the ink transfer rate.

[0068] The carbon number of the bifunctional (meth)acrylate (c) is preferably 8 or more, more preferably 9 or more, and even more preferably 10 or more. By setting the carbon number of the bifunctional (meth)acrylate (c) to be above the lower limit above, the compatibility with resin (a) and polyfunctional (meth)acrylate (b) is appropriately maintained, and as a result, the ink transferability is improved. The carbon number of the bifunctional (meth)acrylate (c) is preferably 18 or less, more preferably 16 or less, and even more preferably 14 or less. By setting the carbon number of the bifunctional (meth)acrylate (c) to be below the upper limit above, deterioration of compatibility with resin (a) and polyfunctional (meth)acrylate (b), increase in ink viscosity, and deterioration of ink transferability are suppressed.

[0069] The content of the difunctional (meth)acrylate (c) in the ink is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more. On the other hand, the content of the difunctional (meth)acrylate (c) in the ink is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 8% by mass or less. By setting the content of the difunctional (meth)acrylate (c) within the above ranges, the compatibility with the resin (a) and the polyfunctional (meth)acrylate (b) is appropriately maintained, and as a result, the ink transferability is improved.

[0070] Examples of difunctional (meth)acrylates (c) include 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,11-undecanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 1,13-tridecanediol di(meth)acrylate, and 1,14-tetradecanediol Examples include 1,10-decanediol di(meth)acrylate, 1,15-pentadecanediol di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, 1,17-heptadecanediol di(meth)acrylate, 1,18-octadecanediol di(meth)acrylate, 4-methyl-1,10-decanediol di(meth)acrylate, and 4-ethyl-1,10-decanediol di(meth)acrylate. Also, polyester di(meth)acrylates having an aliphatic skeleton with 8 to 18 carbon atoms as repeating units are also examples. Of these, 1,10-decanediol di(meth)acrylate is more preferred because it maintains appropriate compatibility with resin (a) and polyfunctional (meth)acrylate (b), and can improve ink transferability. The number of functions refers to the number of structures derived from (meth)acrylate. The bifunctional (meth)acrylate (c) may be used alone or in combination of two or more types.

[0071] The weight-average molecular weight (Mw) of the difunctional (meth)acrylate (c) is preferably 100 or higher, more preferably 150 or higher, and even more preferably 200 or higher. By setting the weight-average molecular weight (Mw) of the difunctional (meth)acrylate (c) to be above the lower limit, the ink coating film becomes more flexible, and as a result, the adhesion to the substrate layer 1 is improved. The weight-average molecular weight (Mw) of the difunctional (meth)acrylate (c) is preferably 1,000 or lower, more preferably 700 or lower, and even more preferably 500 or lower. By setting the weight-average molecular weight (Mw) of the difunctional (meth)acrylate (c) to be below the upper limit, the viscosity of the ink is well maintained, and as a result, the fluidity of the ink is good. The weight-average molecular weight (Mw) of the difunctional (meth)acrylate (c) is measured in polystyrene equivalent using gel permeation chromatography (GPC).

[0072] When the total amount of polyfunctional (meth)acrylate (b) is used as a reference (1.00 parts by mass), the content ratio of difunctional (meth)acrylate (c) is preferably 0.02 parts by mass or more, more preferably 0.04 parts by mass or more, and even more preferably 0.06 parts by mass or more, in order to maintain appropriate compatibility with polyfunctional (meth)acrylate (b) and improve ink transferability. On the other hand, the content ratio of difunctional (meth)acrylate (c) is preferably 0.30 parts by mass or less, more preferably 0.20 parts by mass or less, even more preferably 0.15 parts by mass or less, and particularly preferably 0.10 parts by mass or less.

[0073] When the total amount of resin (a) is used as a reference (1.00 parts by mass), the content ratio of the difunctional (meth)acrylate (c) is preferably 0.10 parts by mass or more, more preferably 0.15 parts by mass or more, and even more preferably 0.20 parts by mass or more, in order to maintain appropriate compatibility with resin (a) and improve ink transferability. On the other hand, the content ratio of the difunctional (meth)acrylate (c) is preferably 0.60 parts by mass or less, more preferably 0.45 parts by mass or less, and even more preferably 0.30 parts by mass or less.

[0074] When the active energy ray-curable resin contained in the ink has urethane bonds, the content of urethane bonds in the ink is preferably 0.05% by mass or less. The content of urethane bonds is measured by nuclear magnetic resonance (NMR).

[0075] <Pigments> The ink preferably contains organic pigments and / or inorganic pigments in addition to an active energy ray curable resin. Examples of organic pigments include phthalocyanine pigments, soluble azo pigments, insoluble azo pigments, lake pigments, quinacridone pigments, isoindoline pigments, slene pigments, and metal complex pigments. Specifically, examples include phthalocyanine blue, phthalocyanine green, azo red, monoazo red, monoazo yellow, disazo red, disazo yellow, quinacridone red, quinacridone magenta, and isoindoline yellow.

[0076] Examples of inorganic pigments include titanium dioxide, zinc oxide, alumina white, calcium carbonate, barium sulfate, red iron oxide, cadmium red, lead yellow, zinc yellow, Prussian blue, ultramarine blue, oxide-coated glass powder, silicate minerals (mica), oxide-coated mica, oxide-coated metal particles, aluminum powder, gold powder, silver powder, copper powder, zinc powder, stainless steel powder, nickel powder, bentonite, iron oxide, carbon black, and graphite.

[0077] For inks printed as a base color for a transparent substrate layer 1, white pigments such as titanium dioxide, zinc oxide, and alumina white are preferred to provide opacity. A particle size of 200-300 nm is preferred for the white pigment, from the viewpoint that scattering can most effectively reduce the transmittance of visible light. The pigment may be used individually or in a mixture of two or more types.

[0078] For organic pigments or carbon black with a specific gravity of 2 or less, the pigment content in the ink is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, from the viewpoint of improving print density. Furthermore, from the viewpoint of improving ink fluidity and obtaining good transferability, the content is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. For inorganic pigments with a specific gravity greater than 2, from the viewpoint of improving print density, the content is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more. Furthermore, from the viewpoint of improving ink fluidity and obtaining good transferability, the content is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less.

[0079] The ink may contain other components such as sensitizers. Furthermore, it is preferable that the ink contains a surfactant. The inclusion of a surfactant in the ink allows it to absorb dampening solution and stabilize the emulsified state during wet printing. The surfactant content in the ink is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, from the standpoint of stabilizing the emulsified state. Additionally, from the standpoint of suppressing mismatch with dampening solution due to excessive absorption of dampening solution during printing, the surfactant content is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less.

[0080] On the other hand, it is preferable that the ink substantially does not contain polymerization initiators. This is because the ink can be cured by irradiation with active energy rays even without the inclusion of polymerization initiators. Here, "substantially contained" does not mean that the presence of polymerization initiators is completely excluded, but rather that polymerization initiators may be present if they are of a type and amount that does not adversely affect the adhesion and reproducibility of the ink layer 4 to the substrate layer 1. In other words, it is not intended that the polymerization initiator content be strictly 0% in all cases. For example, if a trace amount of polymerization initiator is unintentionally included, or if a trace amount of polymerization initiator is intentionally included but does not produce any effect due to that polymerization initiator, it will be considered as not containing a polymerization initiator. Examples of cases where trace amounts of polymerization initiator may be unintentionally included include, in the case of ink or printed material 101 manufacturing equipment, cases where trace amounts of polymerization initiator adhering to containers or pipes contaminate the ink if another product containing polymerization initiator has been manufactured previously, or cases where fine particles of polymerization initiator suspended or volatilized in the air of the manufacturing room adhere to the ink during manufacturing. In such cases, even if the product contains trace amounts of polymerization initiator, it shall be treated as if it substantially does not contain polymerization initiator.

[0081] The viscosity of the ink is measured using a cone-plate rotary viscometer at 25°C and a rotation speed of 0.5 rpm. The viscosity (A) is preferably 5 to 100 Pa·s, more preferably 10 to 80 Pa·s, and even more preferably 20 to 60 Pa·s. Setting the viscosity (A) above the lower limit of each of the above ranges improves the transferability of the ink. Setting the viscosity (A) below the upper limit of each of the above ranges improves the fluidity of the ink, and in the case of white ink in particular, the opacity may be improved.

[0082] At a rotational speed of 50 rpm, the viscosity (B) is preferably 10 to 40 Pa·s, more preferably 15 to 35 Pa·s, and even more preferably 20 to 30 Pa·s. Setting the viscosity (B) above the lower limit of each of the above ranges improves the ink transferability. Setting the viscosity (B) below the upper limit of each of the above ranges can improve the ink transferability.

[0083] The viscosity ratio (B) / (A), which is the ratio of viscosity (A) to viscosity (B), is preferably 0.25 to 0.4, more preferably 0.30 to 0.4, and even more preferably 0.35 to 0.4. By setting the viscosity ratio (B) / (A) within the above range, high-quality printed materials with smooth image areas can be obtained.

[0084] By using an ink containing the above components, setting the ink's physical properties as described above, performing offset printing, and irradiating it with active energy rays (i.e., performing EB offset printing), it becomes possible to achieve high-precision reproducibility comparable to, or even exceeding, that of gravure printing.

[0085] <Base material layer> The base layer 1 is a layer that has affinity for the active energy ray-curable resin. The property of the base layer 1 to "have affinity for the active energy ray-curable resin" is preferably achieved by the base layer 1 containing a resin that has affinity for the active energy ray-curable resin. "Having affinity for the active energy ray-curable resin" means that the surface of the base layer 1 has a property that increases adhesion to the active energy ray-curable resin in the ink layer 4 upon irradiation with active energy rays. The reason why the adhesion of the surface of the base layer 1 increases upon irradiation with active energy rays is not clear, but it is presumed that the active energy rays generate radical active species in the resin molecules present on the surface of the base layer 1, and that these active species interact with the radical active species generated in the molecules of the active energy ray-curable resin in the ink layer 4 in some way, such as crosslinking (covalent bonding), weaker electrostatic interactions (dipole interactions, van der Waals forces, etc.), or other interactions.

[0086] In the reverse printing of this embodiment, it is desirable that the base layer 1 be transparent, or at least semi-transparent, so that the ink layer 4 can be seen. Therefore, a transparent thermoplastic resin is preferably used as the base layer 1. Specifically, examples include polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene; alicyclic polyolefin resins; polyamide resins such as nylon 6 and nylon 66; polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polypropylene terephthalate, polybutyl succinate, polyethylene-2,6-naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, and polyethylene diphenylate; polycarbonate resins; polyarylate resins; polyacetal resins; polyphenylene sulfide resins; fluorine resins such as trifluoroethylene resins, tetrafluoroethylene-hexafluoropropylene copolymers, and vinylidene fluoride resins; acrylic resins; methacrylic resins; polyacetal resins; polyglycolic acid resins; and polylactic acid resins. Of these, polyester resins are preferred because they can enhance strength, heat resistance, and transparency. Polyolefin resins are also preferred because they can enhance transparency, and polyethylene is more preferred. Thermoplastic resins may be used individually or in mixtures of two or more types.

[0087] The base layer 1 may be a single layer or multiple layers. If the base layer 1 is a single layer, it may only have a resin film formed from the thermoplastic resin described above. If the base layer 1 has multiple layers, examples of the base layer 1 include the following laminates. If the base layer 1 has two layers, examples of the base layer 1 include a laminate having the resin film as a base and an easy-adhesion layer described later (resin film / easy-adhesion layer), a laminate having the resin film layer and a barrier layer (first barrier layer) described later (resin film / barrier layer), etc. If the base layer 1 has three layers, examples of the base layer 1 include a laminate having the resin film layer, an easy-adhesion layer and a barrier layer in that order (resin film layer / easy-adhesion layer / barrier layer), a laminate having the resin film and two types of barrier layers (resin film / barrier layer / barrier layer), etc. The barrier layer included in the base layer 1 may be a single layer or multiple layers. Examples of barrier layers include a transparent vapor-deposited layer formed by vapor-depositing an inorganic compound or the like onto the resin film, a barrier coating layer such as polyvinylidene chloride (PVDC), and a stretched film layer such as a stretched (e.g., biaxially oriented) polypropylene (OPP) film. Specific examples of substrate layers 1 having such barrier layers include a transparent vapor-deposited film formed by vapor-depositing an inorganic compound or the like onto the resin film, a PVDC-coated film formed by coating the resin film with polyvinylidene chloride (PVDC), and an OPP barrier film formed by laminating an OPP film onto the resin film.

[0088] The resin film may have multiple layers laminated on it as barrier layers, such as the transparent vapor-deposited layer, the barrier coat layer, and the stretched film layer. For example, the base layer 1 may be a laminate (resin film / transparent vapor-deposited layer / barrier coat layer) in which the resin film, the transparent vapor-deposited layer, and the barrier coat layer are laminated in that order. For example, the base layer 1 may be a laminate (resin film / barrier coat layer) in which the resin film and the barrier coat layer are laminated in that order. In this case, where the base layer 1 has the resin film layer and one or more barrier layers, the ink layer 4 may be laminated on one surface of the base layer 1 (for example, the resin film side surface), or on the other surface (for example, the barrier layer side surface). It is preferable that at least the outermost layer on the ink layer 4 side of the base layer 1 is a resin layer.

[0089] The thickness of the base layer 1 is preferably 9 to 200 μm, more preferably 9 to 100 μm, even more preferably 9 to 50 μm, and particularly preferably 9 to 35 μm. By setting the thickness of the base layer 1 to be above the lower limit of each of the above ranges, it is not made too thin, and the strength of the printed material 101 is increased. Furthermore, by setting the thickness of the base layer 1 to be below the upper limit of each of the above ranges, the processability of the printed material 101 is increased.

[0090] The base layer 1 is preferably surface-treated. Specifically, for example, the base layer 1 is preferably a resin film formed from the thermoplastic resin, on which the surface has been surface-treated. This improves the adhesion between the base layer 1 and the layer adjacent to it.

[0091] The surface treatment method is not particularly limited, but examples include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, glow discharge treatment, and chemical treatments such as oxidation treatment using chemicals.

[0092] The base layer 1 may further contain additives. Examples of additives include crosslinking agents, antioxidants, antiblocking agents, lubricants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

[0093] <Easy adhesion layer> The substrate layer 1 preferably has an easy-adhesion layer to enhance adhesion to the ink layer 4. The easy-adhesion layer is realized by providing a layer (not shown) containing at least one compound selected from, for example, amines, amides, isocyanates, and urethanes as an easy-adhesion layer on the ink layer 4 side surface of the resin film formed by the thermoplastic resin in the substrate layer 1. Functional groups derived from the easy-adhesion layer receive intermolecular forces such as hydrogen bonding with the hydrophilic resin (a) and the polyfunctional (meth)acrylate (b) in the ink, thereby enhancing the transferability of the ink and the adhesion between the ink layer 4 and the substrate layer 1.

[0094] Examples of amines include ethylenediamine, propylenediamine, hexamethylenediamine, phenylenediamine, tolylenediamine, diphenyldiamine, diaminodiphenylmethane, diaminocyclohexylmethane, ethylenediaminetetraacetic acid, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, and other N,N-dialkylaminoalkyl (meth)acrylates, 2-(methacryloyloxy)ethyltrimethylammonium chloride, and 2-(methacryloyloxy)ethyltrimethylammonium chloride. Examples include nium bromide, (meth)acryloyloxyalkyltrialkylammonium salts such as 2-(methacryloyloxy)ethyltrimethylammonium dimethyl phosphate, (meth)acryloylaminoalkyltrialkylammonium salts such as methacryloylaminopropyltrimethylammonium chloride and methacryloylaminopropyltrimethylammonium bromide, tetraalkyl (meth)acrylates such as tetrabutylammonium (meth)acrylate, and trialkylbenzylammonium (meth)acrylates such as trimethylbenzylammonium (meth)acrylate. Amines may be used individually or in combination of two or more.

[0095] Examples of amides include aliphatic amides such as ethylenebisstearamide and hexamethylenebisstearamide, and N,N-dialkylaminoalkyl(meth)acrylamides such as N,N-dimethylaminoethyl(meth)acrylamide, N,N-diethylaminoethyl(meth)acrylamide, and N,N-dimethylaminopropyl(meth)acrylamide. Amides may be used individually or in combination of two or more.

[0096] Examples of isocyanates include aromatic diisocyanates such as tolylene diisocyanate and diphenylmethane-4,4-diisocyanate, aromatic aliphatic diisocyanates such as xylylene diisocyanate, alicyclic diisocyanates such as isophorone diisocyanate, 4,4-dicyclohexylmethane diisocyanate and 1,3-bis(isocyanatemethyl)cyclohexane, aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate, and polyisocyanates obtained by pre-adding these compounds, either individually or in combination, with trimethylolpropane, etc. For example, including amine compounds and isocyanate compounds in the easy-adhesion layer also includes having both an amine group and an isocyanate group in a single compound. Isocyanates may be used individually or in combination of two or more types.

[0097] Urethanes contain at least a polyol and an isocyanate compound, and optionally a chain extender. Urethanes can be obtained, for example, by polymerizing a polyol and an isocyanate compound by a known polymerization method. Examples of polyols include polyester polyols obtained by the reaction of polycarboxylic acids (e.g., malonic acid, succinic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.) or their acid anhydrides with polyhydric alcohols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, neopentyl glycol, 1,6-hexanediol, etc.), polyether polyols such as polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, and polyhexamethylene ether glycol, polycarbonate polyols, polyolefin polyols, and acrylic polyols. Polyurethanes may be used individually or in mixtures of two or more types.

[0098] The content of amines, amides, isocyanates, and urethanes in the easy-adhesion layer is not particularly limited, but is preferably 0.1 to 80% by mass, more preferably 1 to 50% by mass, and even more preferably 5 to 20% by mass.

[0099] The easy-adhesion layer may further contain a resin component. The resin component is not particularly limited as long as it has adhesive properties to the substrate layer 1 and / or the ink layer 4, but for example, polyester resins, polycarbonate resins, epoxy resins, alkyd resins, acrylic resins, urea resins, urethane resins, etc. can be suitably used. Of these, polyester resins, acrylic resins, and urethane resins are preferred, and polyester resins having a phthalate skeleton are more preferred.

[0100] The easy-adhesion layer may appropriately contain various additives such as crosslinking agents, plasticizers, heat stabilizers, weather stabilizers, organic and / or inorganic fine particles, waxes, antioxidants, weathering agents, antistatic agents, and pigments, to the extent that they do not impair the properties of the film. As crosslinking agents, for example, melamine-based crosslinking agents, aziridine-based crosslinking agents, epoxy-based crosslinking agents, methylolated or alkylolated urea-based crosslinking agents, acrylamide-based crosslinking agents, polyamide-based crosslinking agents, oxazoline-based crosslinking agents, carbodiimide-based crosslinking agents, isocyanate-based crosslinking agents, various silane coupling agents, and various titanate-based coupling agents can be used.

[0101] The thickness of the easy-adhesion layer can be adjusted as appropriate depending on optical properties and productivity, but is preferably 10 to 5000 nm, more preferably 50 to 3000 nm, and even more preferably 100 to 1000 nm. Setting the thickness of the easy-adhesion layer above the lower limit makes it easier to uniformly apply the raw material liquid of the easy-adhesion layer onto the substrate layer 1 without defects, and as a result, variations in the adhesion of the easy-adhesion layer are reduced. Setting the thickness of the easy-adhesion layer below the upper limit suppresses the easy-adhesion layer from adversely affecting the optical properties.

[0102] When the easy-adhesion layer contains the same type of resin as the resin in the modified layer 3, for example, when the modified layer 3 contains a urethane-based resin and the easy-adhesion layer contains a urethane-based resin, the affinity between the two is increased, thereby further improving the adhesion of the ink layer 4 to the substrate layer 1.

[0103] <Offset Printing> Figure 2 is a schematic diagram illustrating an example of a printing method used in the present invention. The printing method employed is offset printing.

[0104] Offset printing is a printing method that utilizes the property of oil-based offset printing inks to repel water. Unlike relief printing, which uses printing plates with raised and recessed surfaces, offset printing uses a printing plate 51 without raised and recessed surfaces. Instead of raised and recessed surfaces, the printing plate 51 has an oil-lipophilic image area and a hydrophilic non-image area. Offset printing may be a water-based printing method using dampening solution W (water-based offset printing), or it may be a waterless printing method using a dedicated printing plate 51 to print without using dampening solution (waterless offset printing). In the case of water-based offset printing, during offset printing, first, the non-image area is moistened by dampening solution W supplied to the printing plate 51 from the dampening solution supply roll 52. Next, oil-based ink I is supplied to the printing plate 51 from the ink supply roll 53. At this time, the ink I repels and does not adhere to the non-image area which has been moistened with dampening solution W and is saturated with water, but adheres only to the oil-lipophilic image area. In this way, an image is formed on the surface of the printing plate 51 using ink I, the image using ink I is transferred to the blanket 54, and the image is transferred (printed) from the blanket 54 to the substrate layer 1 which is conveyed by the blanket 54 and the roll 55. When the ink I transferred to the substrate layer 1 hardens, an ink layer 4 is formed, which becomes the printed material 101.

[0105] In waterless offset printing, for example, a printing plate with non-image areas formed by silicone resin can be used. In the waterless offset printing method, the silicone resin repels the ink instead of dampening solution, creating non-image areas. Aside from this point, waterless offset printing is also a printing method common to watered offset printing, which uses dampening solution. Therefore, in this specification, the term "offset printing" is used to include not only watered offset printing, which uses dampening solution, but also waterless offset printing. When adopting waterless offset printing, there is no need to emulsify the dampening solution and ink, so the range of ink choices can be broadened.

[0106] <Color gamut> Offset printing tends to have lower color density and a narrower color gamut compared to gravure printing. This is presumably because offset printing uses a lower pigment content than gravure printing, and also because different types of pigments are suitable for offset printing.

[0107] <Color density> From the viewpoint of increasing color density and widening the color gamut, for example, when using six inks, it is preferable to adjust the ink layer 4 with two complementary colors from the six colors to make the color gamut parameters appropriate. For example, two colors can be selected from orange, green, and purple as complementary colors, and the density of the complementary colors can be appropriately set according to the area where the color gamut is insufficient. Furthermore, even if the adhesion between the substrate layer 1 and the ink layer 4 decreases due to the ink caused by increasing the color density, the modification layer 3 prevents a decrease in adhesion as described above.

[0108] <Halftone shape> In offset printing, defects in the shape of halftone dots, such as roughness, may occur at the edges (borders) of the dots in the image. Possible causes include poor ink transfer and poor release from the blanket.

[0109] From the viewpoint of improving the shape of the halftone dots, it is preferable to appropriately set the shape and material of the ink and process materials (rolls, blankets, etc.). Furthermore, in water-based offset printing, the emulsification suitability of the ink can affect the shape, so it is preferable to use an ink with excellent emulsification suitability.

[0110] <Concealing properties> As mentioned above, in offset printing, the surface of the ink layer is not always smooth, so when the ink particles harden, fine gaps exist between the ink particles in the ink layer. Therefore, when printing with white ink, gaps may occur, potentially reducing opacity. To improve opacity, it is preferable to print with white ink twice, or to print in a shifted position from the first print to fill the gaps created by the first print.

[0111] Furthermore, it is preferable to appropriately set the ink's permeability density and thickness to enhance its opacity. For example, when printing using eight inks, it is effective to use offset printing for seven of the inks and flexographic printing for the white ink. In this case, a varnish suitable for flexographic printing may be used to form a protective layer during flexographic printing.

[0112] Offset printing is solvent-free (does not use organic solvents), thus suppressing odors. Water-based gravure printing can also be solvent-free, but it is difficult to increase the printing speed, resulting in lower productivity. In contrast, offset printing can be printed at a higher speed than gravure printing, and because it is solvent-free, it can increase productivity while reducing the environmental impact.

[0113] <Irradiation with activated energy rays> After ink is printed onto the substrate layer 1, the active energy ray-curable resin contained in the ink is cured by irradiation with active energy rays, and this is fixed to obtain the ink layer 4. Electron beams (EB) are preferred as the active energy rays. When curing the ink with electron beams, the irradiation dose can be appropriately set according to the thickness of the printed ink, the pigment content in the ink, etc. For electron beams, the irradiation dose is preferably 10-100 kGy, more preferably 20-60 kGy, and even more preferably 25-50 kGy. By setting the irradiation dose above the lower limit, the adhesion between the substrate layer 1 and the ink layer 4 can be further improved. Furthermore, by setting the irradiation dose below the upper limit, the decomposition reaction of the active energy ray-curable resin can be suppressed. Irradiation with active energy rays is preferably carried out in a deoxygenated atmosphere (for example, under a nitrogen-filled environment). Irradiation with active energy rays in the presence of oxygen tends to make it difficult for the active energy ray-curable resin to cure. However, by performing the irradiation with active energy rays in a deoxygenated atmosphere, the active energy ray-curable resin can be made to cure more easily.

[0114] <Modified layer> The modified layer 3 is a layer that modifies the ink layer 4. The modified layer 3 contains an ink modifier. After the substrate layer 1 and the ink layer 4 are irradiated with active energy rays and the ink layer 4 hardens, the modified layer 3 is provided on the ink layer 4. The modified layer 3 can also function as an adhesive. The ink modifier may be a one-component curing resin, a two-component curing resin, or a non-curing resin. It may also be a solvent-free resin or a solvent-based resin.

[0115] Examples of ink modifiers include polyether resins, polyester resins, silicone resins, polyamine resins, polybutadiene resins, resins to which epoxy groups have been added, urethane resins, rubber resins, vinyl resins, epoxy resins other than those listed above, phenolic resins, olefin resins, etc. Resins containing biomass components can also be preferably used. Polyamine resins and urethane resins having gas barrier properties are more preferable as ink modifiers. One type of ink modifier may be used alone, or two or more types may be used in mixture.

[0116] The ink modifier more preferably contains a urethane resin. The inclusion of a urethane resin in the ink modifier enhances the adhesion between the substrate layer 1 and the ink layer 4. While the exact mechanism is unclear, it is presumed that, for example, because urethane resins contain amino groups and carboxyl groups in their molecules, they readily engage in chemical interactions (covalent bonding, electrostatic interaction, etc.) with ink particles and the substrate layer 1. The ink modifier may consist of a solvent-free adhesive composition, its cured product, or a mixture thereof, which is also used as an adhesive composition. The adhesive composition used as the ink modifier may be a two-component curing type. If the ink modifier contains two components, a polyisocyanate component and a polyol component, at least a portion of these components may react with each other to form a cured product. The cured product may contain polyurethane. This adhesive composition can be prepared by blending a polyether polyol (manufactured by Toyo Morton Co., Ltd., trade name: EA-N373B, hereinafter referred to as "(A)") as the main component and an aromatic polyisocyanate (manufactured by Toyo Morton Co., Ltd., trade name: EA-N373A, hereinafter referred to as "(B)") as the curing agent. The mass-based blending ratio of each component may be (A):(B) = 100:50. Another example of this adhesive composition can be prepared by blending a polyester polyol (manufactured by Mitsui Chemicals, Inc., trade name: Takelac A626, hereinafter referred to as "(C)") as the main component and an aliphatic polyisocyanate (manufactured by Mitsui Chemicals, Inc., trade name: Takenate A50, hereinafter referred to as "(D)") as the curing agent. The mass-based blending ratio of each component may be (C):(D) = 8:1.

[0117] The thickness of the modified layer 3 can be appropriately set considering factors such as the degree to which the adhesion of the ink layer 4 to the substrate layer 1 can be improved. For example, 0.1 to 20 μm is preferred, 0.5 to 10 μm is more preferred, and 1 to 5 μm is even more preferred.

[0118] The modified layer 3 can be formed, for example, by applying an ink modifier onto the ink layer 4 and drying it using conventionally known methods such as the direct gravure roll coating method, gravure roll coating method, kiss coating method, reverse roll coating method, fontein method, or transfer roll coating method, or by applying it onto the sealant layer 2 (described later), drying it, and then laminating the sealant layer 2 onto the ink layer 4.

[0119] The ratio (T1 / T2) of the thickness of the modified layer 3 to the thickness (T1) of the ink layer 4 is preferably 0.15 to 5. By setting the ratio (T1 / T2) within the above range, the adhesion between the substrate layer 1 and the ink layer 4 is further enhanced. In addition, the heat resistance is improved.

[0120] As described above, by providing the modified layer 3, the ink used in offset printing with active energy ray curable ink is modified. Combined with the fact that the base layer 1 has affinity for active energy ray curable resin, this improves the adhesion between the base layer 1 and the ink layer 4. The mechanism is not entirely clear, but as described above, it is presumed that, for example, the ink modifier penetrates into the gaps between ink particles and into the ink particles, thereby improving the adhesion between ink particles and between the ink particles and the base layer 1.

[0121] <Other layers> The printed material 101 may be provided with other layers, such as a protective layer (impact-resistant layer), an adhesive layer, a barrier layer, a coating layer, an intermediate layer, a sealant layer, and so on. Embodiments of printed materials having these layers will be described later.

[0122] In printed material 101, the content of the same type of resin (e.g., polyethylene) may be 90% by mass or more. In this case, printed material 101 can be constructed as a highly recyclable monomaterial. Alternatively, even in the case of olefin resins, from the viewpoint of recycling, a monoolefin structure may be adopted in which, for example, polyethylene is contained in the sealant layer 2 described later, and polypropylene is contained in the base layer 1, and resins that are not identical but belong to the olefin family are contained in 90% by mass or more.

[0123] As described above, the printed material 101 of this embodiment can improve the adhesion between the substrate layer 1 and the ink layer 4 by including the modified layer 3.

[0124] <Application> Offset printing has lower adhesion between the substrate layer and the ink layer compared to gravure printing, and when applied to packaging for confectionery and other products used at room temperature (light packaging), there is a tendency to require improved adhesion. Furthermore, when applied to packaging for heating or moist heat, such as boiling or retorting, there is a tendency to require even higher adhesion that can withstand the decrease in adhesion due to heat. In this regard, the printed material 101 of this embodiment has an improved adhesion between the substrate layer 1 and the ink layer 4 by including a modified layer 3, so it is possible to meet the adhesion requirements when applied to light packaging. In addition, it is also possible to meet the adhesion requirements when applied to packaging for heating or moist heat. Thus, the printed material 101 can be suitably used not only for light packaging but also for packaging that is heated or moist heat, such as boiled or retorted foods, resealable pouches, and microwaveable products. In this case, examples of heat sterilization treatments applied to the printed material 101 include retorting, boiling, and autoclave treatment. The retort processing temperature may be, for example, 110 to 135°C, and the processing time may be 5 to 120 minutes. The boiling processing temperature may be, for example, 80 to 100°C, and the processing time may be 5 to 120 minutes.

[0125] [Second Embodiment] Figure 3 is a schematic cross-sectional view showing the layer structure of a printed material according to a second embodiment of the present invention. The printed material 102 shown in Figure 3 comprises, from top (front side), a base layer 1, an ink layer 4, a modified layer 3, and a sealant layer 2, in this order.

[0126] The printed material 102 is a laminate formed by reverse offset printing. The printed material 102 has the same configuration as the printed material 101, except that it further comprises a sealant layer 2 provided on the modified layer 3. The base layer 1, ink layer 4, and modified layer 3 of the printed material 102 have the same configuration as those described in the first embodiment, and the printing method and the method of irradiation with active energy rays can also be the same as those in the first embodiment.

[0127] In printed material 102, the modified layer 3 also functions as an adhesive layer. The ink layer 4, hardened by the active energy rays, is relatively hard and tends not to adhere well to adjacent layers. However, the modified layer 3 functions as an adhesive layer, improving adhesion to adjacent layers.

[0128] <Sealant layer> The sealant layer 2 may contain polyethylene, polypropylene, polyethylene terephthalate, polybutylene succinate (PBS), etc. The polyethylene may be low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), or very low-density polyethylene (VLDPE), but linear low-density polyethylene (LLDPE) is preferred. The polypropylene is preferably unstretched polypropylene (CPP). Unstretched polyethylene, polyethylene terephthalate, and polybutylene succinate are also preferred. Thus, the sealant layer 2 is preferably an unstretched film, but other stretched films such as heat-sealable stretched polypropylene (HSOPP) and heat-sealable polyethylene terephthalate (HSPET) can also be used.

[0129] From the perspective of reducing environmental impact, polyethylene may be biomass-derived polyethylene or recycled polyethylene.

[0130] The sealant layer 2 may contain other additives. The polyethylene content in the sealant layer 2 is preferably 50% by mass or more, and more preferably 80% by mass or more.

[0131] The sealant layer 2 may be transparent or opaque. When the sealant layer 2 is transparent, the contents of the printed material 102 are easily visible when used as packaging. When the sealant layer 2 is opaque, the contents of the printed material 102 do not obstruct the visibility of information such as characters and images displayed in the ink layer 4 when used as packaging. When the sealant layer 2 is opaque, it is preferable that the sealant layer 2 be white, gray, black, etc. These white, gray, black, etc. sealant layers 2 can improve the visibility of information displayed in the ink layer 4.

[0132] If the printed material 102 has a sealant layer 2 on the side of the modified layer 3 opposite to the ink layer 4, the modified layer 3 can function as an adhesive layer. In this case, the sealant layer 2 can also be subjected to heat sealing.

[0133] The thickness of the sealant layer 2 can be set appropriately considering the shape of the packaging bag to be manufactured and the mass of the contents to be contained, but for example it can be 5 to 150 μm.

[0134] The sealant layer 2 can be formed, for example, by directly laminating an unstretched polyethylene film onto the modified layer 3, or by extruding molten polyethylene onto the modified layer 3.

[0135] The sealant layer 2 may contain titanium dioxide. In this case, the sealant layer 2 can be configured as a light-shielding sealant layer for retort packaging. This suppresses the hardening and degradation of polyethylene due to light, and as a result, the decrease in seal strength is suppressed.

[0136] Thus, when the modified layer 3 has a sealant layer 2 on the side opposite to the ink layer 4, the modified layer 3 can also function as an adhesive layer that bonds the substrate layer 1 and the sealant layer 2.

[0137] <Color difference> The printed matter 102 deteriorates due to the heat of heat sealing, and this deterioration can appear as color tone. It is preferable that the color difference (ΔE) obtained by the following formula (A) before and after heating and pressurizing under the heat sealing conditions of a temperature of 220°C, a pressure of 0.2 MPa, and a time of 1.5 seconds is less than 3.0. By setting the color difference within the above range, the color difference before and after heat sealing can be reduced. As a result, the heat resistance of the printed matter 102 is enhanced.

[0138] [Number] [[ID=Y14]][In the above formula (A), ΔL * [[ID=Y16]], Δa * [[ID=Y18]], and Δb * [[ID=Y20]] represent the differences in lightness (L * [[ID=Y22]]a * [[ID=Y24]]b * [[ID=Y26]] color space) before and after heating and pressurizing under the above heat sealing conditions, respectively, of lightness (L * [[ID=Y28]]), chromaticity (a * [[ID=Y30]]), and saturation (b * [[ID=Y32]]).]

[0139] From the point of sufficiently suppressing discoloration during heat sealing, the upper limit of the above color difference is preferably 1.5 or less, more preferably 1.3 or less. From the viewpoint of ease of manufacture, the lower limit of the above color difference is preferably 0.1 or more, more preferably 0.3 or more. When the printed matter 102 is viewed in plan from the base material layer 1 side, the coating ratio by the ink layer 4 with respect to the entire area of the region (area) to be the measurement target of the above color difference may be 50 area% or more, may be 70 area% or more, or may be 100 area%. The fact that this coating ratio is 100 area% means that the entire region to be the measurement target of "color difference" is covered by the ink layer 4. The fact that this coating ratio is 50 area% means that half of the region to be the measurement target of "color difference" is covered by the ink layer 4.

[0140] While the exact factors that can reduce the color difference before and after heat sealing are unclear, it is presumed that the components contained in the modified layer 3 have the effect of coagulating the ink in the ink layer 4 and improving the strength of the ink layer 4 itself, as well as improving the adhesive strength between the ink layer 4 and the adjacent layer. As a result, gaps are suppressed at the interface between the ink layer 4 and the modified layer 3, the ink layer 4 is prevented from moving and deforming, and the ink layer 4 is prevented from rupturing. Consequently, it is presumed that discoloration associated with gaps, deformation, and rupture is suppressed, and discoloration of the ink layer 4 is sufficiently suppressed.

[0141] <Discoloration spots> The number of discoloration spots in the printed material 102 can serve as an indicator of the heat resistance of the printed material 102. When the sealant layer 2 of the printed material 102 is heated and pressurized under heat sealing conditions of 220°C, 0.2 MPa, and 1.5 seconds, the number of discoloration spots with a size of 20 μm or larger that occur is 1 mm². 2 It is preferable that there be 10 or fewer per unit. This suppresses discoloration of the sealed area and sufficiently suppresses discoloration caused by heat sealing. Therefore, the heat resistance of the printed material 102 is improved.

[0142] <Relationship between lamination strength change rate and ink coverage rate> The ink modifier in the modified layer 3 may have the function of crosslinking the ink forming the ink layer 4 along with forming urethane bonds. This improves the adhesive strength between the ink layer 4 and the sealant layer 2 or adjacent layers. Even if the ink coverage rate in the ink layer 4 is high, the epoxy compound can be sufficiently penetrated into the ink layer 4 by increasing the content of the epoxy compound in the ink modifier accordingly. The penetrated epoxy compound can increase the strength of the ink layer 4 by crosslinking the ink. Therefore, even if the ink coverage rate in the ink layer 4 is high, discoloration associated with heat sealing is suppressed. Consequently, the heat resistance of the printed material 102 is improved.

[0143] <Lamination Strength> The printed material 102 preferably has an adhesive strength of 0.5 to 4.0 N / 15 mm, as measured in accordance with JIS K 6854-1:1999. The adhesive strength can be determined, for example, by cutting the printed material 102 into a 15 mm wide sample, peeling the interlayers at the edges of the sample, and then measuring the peel strength between the layers of the laminate using a tensile testing machine under conditions of angle: 90°, tensile speed: 300 mm / min, and room temperature. This peel strength can then be determined as the adhesive strength at room temperature (20°C). By setting the adhesive strength within the above range, the lamination strength of the printed material 102 can be increased.

[0144] <Bag tear resistance when heated> Preferably, when the printed material 102 is heated and pressurized under heat-sealing conditions of 220°C, 0.2 MPa, and 1.5 seconds to form a bag, and then heated in a microwave oven (output: 600W) for 3 minutes, there is no tearing of the seal. This enhances the heat resistance of the printed material 102. In particular, the printed material 102 is suitable for use as packaging material for microwave-heated food.

[0145] <Peel bond strength> When the printed material 102 is heated and pressurized under heat sealing conditions of 220°C, 0.2 MPa, and 1.5 seconds, and then exposed to a steam-containing atmosphere, the peel adhesion strength after exposure of the outer surface (substrate layer 1 side) is S1, and the peel adhesion strength after exposure of the inner surface (sealant layer 2 side) is S2, the ratio (S2 / S1) is preferably 0.6 to 1.6. This enhances the heat resistance of the printed material 102. In particular, the printed material 102 is suitable when used as packaging material for retort foods.

[0146] In the printed material 102, the content of the same type of resin (for example, polyethylene, etc.) may be 90% by mass or more. In this case, the printed material 102 can be constructed as a highly recyclable monomaterial. Alternatively, even in the case of olefin resins, from the viewpoint of recycling, a monoolefin structure may be adopted in which, for example, polyethylene is used in the sealant layer 2 and polypropylene is used in the base layer 1, containing 90% by mass or more of resins that are not identical but belong to the olefin family.

[0147] As described above, the printed material 102 of this embodiment includes a modified layer 3, which improves the adhesion between the substrate layer 1 and the ink layer 4. Furthermore, the heat resistance is further enhanced by providing the modified layer 3.

[0148] <Application> Because the printed material 102 has improved adhesion between the base material layer 1 and the ink layer 4, as well as improved heat resistance, it can be suitably used for boiled or retort foods (boiling or retort processing), resealed pouches (usually, welding between the welded portion and the sealant layer 2 at the non-sealed portion is performed by heating to 150°C or higher), cans, steam vents, and packaging that is retorted and heated by the end consumer, such as by microwave heating, or subjected to moist heat.

[0149] The printed material 102 can also be used in packaging such as laminate tubes. In this case, for example, a second sealant layer (not shown) is further laminated on the upper side of the base material layer 1 in the printed material 102 shown in Figure 3 (i.e., on the side opposite to the ink layer 4 in the base material layer 1). The printed material 102 comprises the second sealant layer, the base material layer 1, the ink layer 4, the modified layer 3, and the sealant layer (first sealant layer) 2 in this order from the top (surface side). The printed material 102 is fed out and rolled into a cylindrical shape so that the second sealant layer is on the outer side, the first sealant layer 2 is on the inner side, and the direction perpendicular to the flow direction (MD) is the circumferential direction. The body tube is obtained by heat welding the overlapping portions of the outermost layer, the second sealant layer, and the innermost layer, the first sealant layer 2, at both circumferential edges of the printed material 102. A body portion that can be filled with contents is formed by closing one end of the body tube in the axial direction (i.e., the flow direction) by heat welding. A laminate tube comprising a body portion and a shoulder portion is formed by attaching a resin shoulder portion to the other end of this body portion (which is open). The first sealant layer 2 and the second sealant layer can be single-layer or multi-layer, but from the viewpoint of processability, it is preferable to use unstretched polyethylene (PE) film. The first sealant layer 2 and the second sealant layer may have the same configuration or different configurations.

[0150] [Third Embodiment] Figure 4 is a schematic cross-sectional view showing the layer structure of a printed material according to the third embodiment of the present invention. The printed material 103 shown in Figure 4 is a laminate formed by reverse offset printing. The printed material 103 comprises, from the top (surface side), a base layer 1, an ink layer 4, a modified layer 3, a barrier layer 5, an adhesive layer 7, and a sealant layer 2, in this order.

[0151] The printed material 103 has the same configuration as the printed material 102, except that it further includes a barrier layer 5 on the side of the modified layer 3 opposite to the ink layer 4, and an adhesive layer 7 between the barrier layer 5 and the sealant layer 2. The base layer 1, ink layer 4, modified layer 3, and sealant layer 2 of the printed material 103 have the same configuration as those described in the second embodiment, and the printing method and the method of irradiation with active energy rays can also be the same as those in the second embodiment.

[0152] <Barrier layer> The barrier layer (second barrier layer) 5 is, for example, a gas barrier layer that improves the oxygen barrier and water vapor barrier properties of the printed material 103. The barrier layer 5 preferably includes an inorganic compound layer, or an inorganic compound layer and a coating layer. When the barrier layer 5 includes an inorganic compound layer and a coating layer, it is preferable that the inorganic compound layer and the coating layer are laminated in that order from the side of the modified layer 3. When microwave heating by a microwave oven is anticipated, the barrier layer 5 is preferably an inorganic oxide layer, a resin-containing layer, or a combination thereof.

[0153] <Inorganic compound layer> The inorganic compound layer may be formed by coating, or by depositing the inorganic compound.

[0154] Examples of inorganic compounds contained in the inorganic compound layer include metal oxides such as silicon oxide, boron oxide, aluminum oxide, magnesium oxide, calcium oxide, potassium oxide, tin oxide, sodium oxide, titanium oxide, lead oxide, zirconium oxide, and yttrium oxide. The inorganic compound layer is preferably a vapor-deposited film made of a metal oxide. From the viewpoint of transparency and barrier properties, aluminum oxide, silicon oxide, and magnesium oxide are preferred as metal oxides. Furthermore, considering cost, aluminum oxide and silicon oxide are more preferred as metal oxides. Furthermore, from the viewpoint of excellent tensile stretchability during processing, silicon oxide is even more preferred as the metal oxide. By making the inorganic compound layer a vapor-deposited film made of a metal oxide, high barrier properties can be obtained with a very thin layer that does not affect the recyclability of the printed material 103.

[0155] Because metal oxide vapor-deposited films are transparent, they have the advantage of making it less likely for users handling printed packaging materials to perceive the feel of metal, compared to vapor-deposited films made of metal.

[0156] The thickness of the vapor-deposited film made of aluminum oxide is preferably 5 to 30 nm, and more preferably 7 to 15 nm. By setting the thickness of the vapor-deposited film made of aluminum oxide to be above the lower limit, sufficient gas barrier properties can be obtained. By setting the thickness of the vapor-deposited film made of aluminum oxide to be below the upper limit, it is possible to suppress the occurrence of cracks due to deformation caused by internal stress in the thin film and suppress the decrease in gas barrier properties. Although it is still possible to use the printed material 103 even if the thickness of the vapor-deposited film exceeds the upper limit, the cost will increase due to the increase in material usage and the lengthening of the film formation time.

[0157] The thickness of the silicon dioxide vapor-deposited film is preferably 10 to 50 nm, and more preferably 20 to 40 nm. By setting the thickness of the silicon dioxide vapor-deposited film to be above the lower limit, sufficient gas barrier properties can be obtained. By setting the thickness of the silicon dioxide vapor-deposited film to be below the upper limit, it is possible to suppress the occurrence of cracks due to deformation caused by internal stress in the thin film and suppress the decrease in gas barrier properties. Although the printed material 103 itself can be used even if the thickness of the vapor-deposited film exceeds the upper limit, the cost will increase due to the increase in material usage and the lengthening of the film formation time.

[0158] Inorganic compound layers can be formed, for example, by vacuum deposition. Vacuum deposition can utilize either physical vapor deposition or chemical vapor deposition. Examples of physical vapor deposition include, but are not limited to, vacuum evaporation, sputtering, and ion plating. Examples of chemical vapor deposition include, but are not limited to, thermal CVD (Chemical Vapor Deposition), plasma CVD, and photoCVD.

[0159] In the vacuum deposition described above, resistance heating vacuum deposition, electron beam heating vacuum deposition, induction heating vacuum deposition, sputtering, reactive sputtering, dual magnetron sputtering, plasma chemical vapor deposition (PECVD), etc., are preferably used. However, considering productivity, vacuum deposition is preferred. For the heating means in vacuum deposition, it is preferable to use one of electron beam heating, resistance heating, or induction heating.

[0160] <Coating layer> The coating layer, like the inorganic compound layer, has gas barrier properties. The coating layer can be formed, for example, by coating. In this case, a coating solution containing resins such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, polyvinylidene chloride, polyacrylonitrile, and epoxy resins can be used. Organic particles or inorganic particles, inorganic layered compounds, curing agents, etc., may be added to this coating solution.

[0161] The coating layer may be an organic-inorganic composite layer comprising, for example, at least one of a metal alkoxide, a hydrolysate of a metal alkoxide, and a reaction product of a hydrolysate of a metal alkoxide, and a water-soluble polymer. This organic-inorganic composite layer may further contain a silane coupling agent, a hydrolysate of a silane coupling agent, a reaction product of a hydrolysate of a silane coupling agent, and the like.

[0162] Examples of metal alkoxides and their hydrolysates contained in the organic-inorganic composite layer include tetraethoxysilane [Si(OC2H5)4], triisopropoxyaluminum [Al(OC3H7)3], and other metal alkoxides with the general formula M(OR). n Examples include compounds represented by [the formula] and their hydrolysates. One of these may be used alone, or two or more may be used in combination.

[0163] In the coating solution used to form the organic-inorganic composite layer, the total content of metal alkoxides, their hydrolysates, or their reaction products is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 65% ​​by mass or more, from the viewpoint of oxygen barrier properties. In the above coating solution, the total content of metal alkoxides, their hydrolysates, and their reaction products is preferably 70% by mass or less.

[0164] The water-soluble polymer contained in the organic-inorganic composite layer is not particularly limited and includes, for example, polysaccharides such as polyvinyl alcohol polymers, starch, methylcellulose, and carboxymethylcellulose, and hydroxyl group-containing polymers such as acrylic polyol polymers. From the viewpoint of further improving oxygen barrier properties, it is preferable that the water-soluble polymer contains a polyvinyl alcohol polymer. The degree of polymerization of the water-soluble polymer is preferably, for example, 300 to 4500.

[0165] The polyvinyl alcohol-based polymer contained in the organic-inorganic composite layer can be obtained, for example, by saponifying (including partial saponification) polyvinyl acetate. This water-soluble polymer may have several percent to several tens of percent of acetate groups remaining.

[0166] The water-soluble polymer content in the coating solution used to form the organic-inorganic composite layer is preferably 15% by mass or more, and more preferably 20% by mass or more. On the other hand, the water-soluble polymer content in the coating solution used to form the organic-inorganic composite layer is preferably 50% by mass or less, and more preferably 45% by mass or less.

[0167] Examples of silane coupling agents used in organic-inorganic composite layers include silane coupling agents having organic functional groups. Examples of silane coupling agents include ethyltrimethoxysilane, vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, glycidooxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropylmethyldimethoxysilane. A silane coupling agent selected from these, its hydrolysate, or one of their reaction products may be used alone or in combination of two or more.

[0168] As a silane coupling agent, one having an epoxy group as an organic functional group is preferred. Examples of silane coupling agents having an epoxy group include γ-glycidooxypropyltrimethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Silane coupling agents having an epoxy group may also have organic functional groups other than the epoxy group, such as vinyl groups, amino groups, methacrylic groups, and ureyl groups. A silane coupling agent selected from these, its hydrolysate, or one of their reaction products may be used alone or as a mixture of two or more.

[0169] Silane coupling agents having organic functional groups, their hydrolysates, and their reaction products enhance the oxygen barrier properties of the coating layer and the adhesion to adjacent layers through the interaction of their organic functional groups with the hydroxyl groups of water-soluble polymers. In particular, when the silane coupling agent, its hydrolysate, and their reaction products have epoxy groups and the water-soluble polymer is polyvinyl alcohol, the interaction between the epoxy groups and the hydroxyl groups of polyvinyl alcohol further enhances the oxygen barrier properties and the adhesion to adjacent layers.

[0170] In the coating solution used to form the organic-inorganic composite layer, the total content of the silane coupling agent, its hydrolysate, and their reaction products is preferably 1% by mass or more, and more preferably 2% by mass or more. On the other hand, the total content of the silane coupling agent, its hydrolysate, and their reaction products in the above coating solution is preferably 15% by mass or less, and more preferably 12% by mass or less.

[0171] The thickness of the coating layer is preferably 50 to 1000 nm, and more preferably 100 to 500 nm. By setting the thickness of the coating layer above the lower limit, sufficient gas barrier properties can be obtained, and by setting it below the upper limit, sufficient flexibility can be maintained.

[0172] It is preferable that the barrier layer 5 is surface-treated, as is the case with the substrate layer 1 in the first embodiment described above. This improves the adhesion between the barrier layer 5 and adjacent layers. Nanocomposite materials may also be used for the barrier layer 5.

[0173] <Adhesive layer> The adhesive layer 7 bonds the barrier layer 5 and the sealant layer 2. The adhesive layer 7 may be a layer having the same configuration as the modified layer 3 of the first embodiment. Alternatively, the adhesive layer 7 may contain an adhesive as described below.

[0174] The adhesive layer 7 contains at least one type of adhesive. The adhesive may be a one-component curing adhesive, a two-component curing adhesive, or a non-curing adhesive. The adhesive may also be a solvent-free adhesive or a solvent-based adhesive.

[0175] Adhesives for forming the adhesive layer 7 include polyether-based adhesives, polyester-based adhesives, silicone-based adhesives, polyamine-based adhesives, adhesives to which epoxy groups have been added, urethane-based adhesives, rubber-based adhesives, vinyl-based adhesives, epoxy-based adhesives other than those listed above, phenol-based adhesives, olefin-based adhesives, etc. Adhesives containing biomass components can also be preferably used. Polyamine-based adhesives and urethane-based adhesives are more preferred. The adhesive may have gas barrier properties. The adhesive may be used alone or in mixture of two or more types. Specific examples of gas barrier adhesives include "Maxive®" manufactured by Mitsubishi Gas Chemical Company, Inc. and "Paslim®" manufactured by DIC Corporation.

[0176] The thickness of the adhesive layer 7 is preferably 0.1 to 20 μm, more preferably 0.5 to 10 μm, and even more preferably 1 to 5 μm.

[0177] The adhesive layer 7 can be formed by applying and drying it on the sealant layer 2 using conventionally known methods such as the direct gravure roll coating method, gravure roll coating method, kiss coating method, reverse roll coating method, fontein method, and transfer roll coating method.

[0178] In the printed material 103, the content of the same type of resin (for example, polyethylene, etc.) may be 90% by mass or more. In this case, the printed material 103 can be constructed as a highly recyclable monomaterial. Alternatively, even in the case of olefin resins, from the viewpoint of recycling, a monoolefin structure may be adopted in which the sealant layer 2 contains polyethylene and the base layer 1 contains polypropylene, for example, resins that are not identical but belong to the olefin family, in a composition of 90% by mass or more.

[0179] As described above, the printed material 103 of this embodiment provides the same effects as the printed material 101 of the first embodiment and the printed material 102 of the second embodiment. In addition, it also provides the effects attributed to the barrier layer 5.

[0180] <Application> The printed material 103 can be used for the same purposes as the printed material 101 of the first embodiment and the printed material 102 of the second embodiment.

[0181] [Fourth Embodiment] Figure 5 is a schematic cross-sectional view showing the layer structure of a printed material according to the fourth embodiment of the present invention. The printed material 104 shown in Figure 5 is a laminate formed by reverse offset printing. The printed material 104 comprises, from the top (surface side), a protective layer 6, a substrate layer 1, an ink layer 4, a modified layer 3, and a sealant layer 2, in this order.

[0182] The printed material 104 has the same configuration as the printed material 102, except that it further comprises a protective layer 6 on the surface of the base material layer 1. The base material layer 1, ink layer 4, modified layer 3, and sealant layer 2 of the printed material 104 have the same configuration as those described in the second embodiment, and the printing method and the method of irradiation with active energy rays can also be the same as those in the second embodiment.

[0183] <Protective layer> The printed material 104 includes a protective layer 6 as its outermost layer. The protective layer 6 is formed on at least a portion of the outer layer side of the transparent substrate layer 1. The protective layer 6 may be any transparent resin layer, and the resin is not particularly limited. When the printed material 104 is a metallic printed material having a metallic reflective layer, it is preferable to form the protective layer 6 in a position such that, when the printed material 104 is viewed from above, the protective layer 6 overlaps with at least a portion of the area having the metallic reflective layer. By arranging the protective layer 6 to overlap at least a portion of the area having the metallic reflective layer in the planar direction, the metallic luster based on the metallic reflective layer can be adjusted, and the aesthetic appeal can be improved. Furthermore, by arranging the protective layer 6 to overlap at least a portion of the area having the metallic reflective layer in the planar direction, and by arranging the internal scattering layer to overlap at least a portion of the area having the protective layer 6, even if the surface is rubbed, the traces of abrasion will not be noticeable, and a decrease in aesthetic appeal can be suppressed. The protective layer 6 may be positioned so as to overlap all of the areas having the metallic reflective layer in the planar direction, but from the viewpoint of creating a contrast in metallic luster depending on the presence or absence of the protective layer 6, it is preferable to position it so as to overlap only a portion of the areas having the metallic reflective layer.

[0184] In the printed material 104, the content of the same type of resin (for example, polyethylene, etc.) may be 90% by mass or more. In this case, the printed material 104 can be constructed as a highly recyclable monomaterial. Alternatively, even in the case of olefin resins, from the viewpoint of recycling, a monoolefin structure may be adopted in which, for example, polyethylene is used in the sealant layer 2 and polypropylene is used in the base layer 1, containing 90% by mass or more of resins that are not identical but belong to the olefin family.

[0185] As described above, the printed material 104 of this embodiment provides the same effects as the printed material 101 of the first embodiment and the printed material 102 of the second embodiment. In addition, it also provides the effects attributed to the protective layer 6.

[0186] <Application> The printed material 104 can be used for the same purposes as the printed material 101 of the first embodiment and the printed material 102 of the second embodiment.

[0187] [Fifth Embodiment] Figure 6 is a schematic cross-sectional view showing the layer structure of a printed material according to the fifth embodiment of the present invention. The printed material 105 shown in Figure 6 is a laminate formed by reverse offset printing. The printed material 105 comprises, from the top (surface side), a base layer 1, an ink layer 4, a modified layer 3, an intermediate layer 8, an adhesive layer 7, and a sealant layer 2, in this order.

[0188] The printed material 105 has the same configuration as the printed material 103, except that it has an intermediate layer 8 between the modified layer 3 and the adhesive layer 7 instead of the barrier layer 5. The base layer 1, ink layer 4, modified layer 3, adhesive layer 7, and sealant layer 2 of the printed material 105 have the same configuration as those described in the third embodiment, and the printing method and the method of irradiation with active energy rays can also be the same as those in the third embodiment.

[0189] <Middle class> The intermediate layer 8 may contain polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene; alicyclic polyolefin resins; polyamide resins such as nylon 6 and nylon 66; polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polypropylene terephthalate, polybutyl succinate, polyethylene-2,6-naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, and polyethylene diphenylate; polycarbonate resins; polyarylate resins; polyacetal resins; polyphenylene sulfide resins; trifluoroethylene resins; tetrafluoroethylene-hexafluoropropylene copolymers; vinylidene fluoride resins; fluorine resins; acrylic resins; methacrylic resins; polyacetal resins; polyglycolic acid resins; polylactic acid resins, etc. The resins contained in the intermediate layer 8 may be the same as or different from the resins contained in the base layer 1. The intermediate layer 8 may be an aluminum-deposited resin film in which an aluminum-deposited layer is formed on a resin film. The intermediate layer 8 may also contain aluminum foil. By including aluminum foil in the intermediate layer 8, the printed material 105 can be given a metallic luster and its barrier properties can be improved. Alternatively, the intermediate layer 8 may have the same configuration as the base layer 1 of the first embodiment.

[0190] The thickness of the intermediate layer 8 is preferably 5 to 200 μm, more preferably 6.5 to 100 μm, even more preferably 7 to 50 μm, and particularly preferably 7 to 35 μm, similar to the substrate layer 1.

[0191] The intermediate layer 8 may be colored, and may be white, gray, black, or the like.

[0192] In the printed material 105, the content of the same type of resin (for example, polyethylene, etc.) may be 90% by mass or more. In this case, the printed material 105 can be constructed as a highly recyclable monomaterial. Alternatively, even in the case of olefin resins, from the viewpoint of recycling, a monoolefin structure may be adopted in which the sealant layer 2 contains polyethylene and the base layer 1 contains polypropylene, for example, resins that are not identical but belong to the olefin family, in a composition of 90% by mass or more.

[0193] As described above, the printed material 105 of this embodiment provides the same effects as the printed material 103 of the third embodiment. In addition, it also provides the effects attributed to the intermediate layer 8.

[0194] <Application> The printed material 105 can be used for the same purposes as the printed material 101 of the first embodiment and the printed material 102 of the second embodiment.

[0195] [Sixth Embodiment] Figure 7 is a schematic cross-sectional view showing the layer structure of a printed material according to the sixth embodiment of the present invention. The printed material 106 shown in Figure 7 is a laminate formed by offset printing on the front side. The printed material 106 comprises, from the top (surface side), a modified layer 3, an ink layer 4, and a substrate layer 1 in that order.

[0196] The printed material 106 is obtained by applying ink to the substrate layer 1 by printing, then applying a modified layer 3 to the ink layer 4 before irradiation with active energy rays, and then irradiating the modified layer 3 with active energy rays from the modified layer 3 side while the substrate layer 1, ink layer 4, and modified layer 3 are stacked, causing them to harden. The ink layer 4 of the printed material 106 has the same configuration as described in the first embodiment, and the printing method and the method of irradiating with active energy rays can also be the same as in the first embodiment.

[0197] As described above, in offset printing, due to the printing method and the leveling properties of the ink, the surface of the ink layer is not necessarily smooth, and because fine air bubbles exist in the ink, gaps are created between ink particles, and it is presumed that air bubbles are mixed into the ink particles. Even if an ink modifier is applied to the ink layer 4 before irradiation with active energy rays, it is presumed that when the active energy rays are irradiated, the ink modifier penetrates into the gaps between the ink particles of the hardened ink layer 4 and into the air bubbles within the ink particles, and when the active energy rays are irradiated in this state, the adhesion between ink particles and between the substrate layer 1 and the ink layer 4 is improved, similar to the first embodiment.

[0198] <Base material layer> As the base layer 1, a resin film having the same configuration as in the first to fifth embodiments can be used. On the other hand, since transparency is not required for the base layer 1 in the printed material 106, the degree of freedom for the base layer 1 is increased. For example, the base layer 1 may be colored or it may be milky white.

[0199] Here, offset printing tends to print with thicker ink than gravure printing, but it is prone to white spots and has a tendency to have reduced opacity. One way to improve opacity is to lower the viscosity of the ink, but lowering the viscosity may reduce the adhesion between the substrate layer 1 and the ink layer 4. On the other hand, as mentioned above, increasing the viscosity of the ink may reduce the fluidity, dispersibility, and leveling properties of the ink, which may reduce the accuracy (reproducibility) of the printing. However, if the substrate layer 1 is milky white, adhesion can be improved without lowering the viscosity of the ink. In addition, white printing becomes unnecessary, which can reduce the number of processes in printing. The opacity of the substrate layer 1 is preferably 40% or more, and more preferably 50% or more.

[0200] <Paper sheet> A paper sheet can also be used as the base layer 1. The paper sheet may comprise a paper layer and a clay coat layer. The paper layer may be made primarily from plant-derived pulp. Specific examples of paper sheets include fine paper, special fine paper, coated paper, art paper, cast coated paper, imitation paper, kraft paper, and glassine paper.

[0201] The basis weight of paper sheets is 20-500 g / m². 2 Preferably, 30-200 g / m 2 This is preferable.

[0202] The thickness of the paper sheet is preferably 20 to 150 μm, and more preferably 30 to 100 μm.

[0203] The paper sheet may include a vapor-deposited layer laminated on a paper layer or a clay coat layer.

[0204] <Vapour-deposited layer> The vapor-deposited layer is a layer formed by depositing a metal or inorganic compound. For example, a vapor-deposited layer formed by depositing aluminum can be used. The vapor-deposited layer is made of aluminum oxide (AlO x ), silicon dioxide (SiO₂) x ) and other similar items may also be included.

[0205] The paper sheet is not limited to one in which a vapor-deposited layer is formed on a paper layer, but may also be one in which a paper layer and a metal (for example, aluminum foil) are bonded together with an adhesive.

[0206] <Modified layer> In printed material 106, the modified layer 3 is a transparent layer for protecting the ink layer 4 and also functions as a surface protective layer (overcoat layer). The modified layer 3 contains a transparent active energy ray curable resin as an ink modifier. As the active energy ray curable resin, a transparent resin mainly composed of a prepolymer (including oligomers) and / or monomers containing radical polymerizable double bonds in its molecule that crosslink (cure) by irradiation with active energy rays such as electron beams can be used. Here, "main component" means that it is present in an amount of 50% by weight or more, preferably 70% by weight or more, and more preferably 90% by weight or more.

[0207] Specifically, examples of prepolymers and monomers include compounds having radically polymerizable unsaturated groups such as (meth)acryloyl groups and (meth)acryloyloxy groups, and cationic polymerizable functional groups such as epoxy groups in the molecule. Here, (meth)acryloyl group means acryloyl group and / or methacryloyl group.

[0208] Examples of prepolymers having radically polymerizable unsaturated groups include polyester (meth)acrylate, urethane (meth)acrylate, epoxy (meth)acrylate, melamine (meth)acrylate, triazine (meth)acrylate, and silicone (meth)acrylate. The weight-average molecular weight (Mw) of these is preferably around 250 to 100,000. The weight-average molecular weight (Mw) is measured using gel permeation chromatography (GPC) on a polystyrene basis.

[0209] Examples of the monomer having a radically polymerizable unsaturated group include, as a monofunctional monomer, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenoxyethyl (meth) acrylate, and the like. Examples of the polyfunctional monomer include diethylene glycol di(meth) acrylate, propylene glycol di(meth) acrylate, trimethylolpropane tri(meth) acrylate, trimethylolpropane ethylene oxide tri(meth) acrylate, dipentaerythritol tetra(meth) acrylate, dipentaerythritol penta(meth) acrylate, dipentaerythritol hexa(meth) acrylate, and the like.

[0210] Examples of the prepolymer having a cationically polymerizable functional group include prepolymers of epoxy resins such as bisphenol type epoxy resins and novolac type epoxy compounds, and vinyl ether resins such as fatty acid vinyl ethers and aromatic vinyl ethers. As the prepolymer, a polyene / thiol prepolymer formed by a combination of a polyene and a polythiol is also preferable. Examples of the thiol include polythiols such as trimethylolpropane trithioglycolate and pentaerythritol tetrathioglycolate. Examples of the polyene include those obtained by adding allyl alcohol to both ends of a polyurethane formed from a diol and a diisocyanate.

[0211] The ink modifier preferably contains an acrylic resin. By the ink modifier containing an acrylic resin, the modified layer 3 can also function as a surface protection layer (overcoat layer) that protects the surface of the ink layer 4.

[0212] The transparent active energy ray-curable resin may be used alone or in combination of two or more.

[0213] The thickness of the modified layer 3 is preferably 0.1 to 10 μm. By setting the thickness of the modified layer 3 to be not less than the above lower limit, various resistances such as scratch resistance, abrasion resistance, and weather resistance are improved. By setting the thickness of the modified layer 3 to be not more than the above upper limit, it is not necessary to use an excessive amount of resin material, and the cost is reduced.

[0214] In the printed matter 106, the content of the same kind of resin (for example, polyethylene, etc.) may be 90% by mass or more. In this case, the printed matter 106 can be configured as a highly recyclable monomaterial. Alternatively, even in the case of an olefin-based resin, from the viewpoint of recycling, for example, a monoolefin configuration in which the sealant layer 2 contains 90% by mass or more of a resin belonging to the olefin-based but not the same, such as polyethylene, and the base material layer 1 contains polypropylene, may be used.

[0215] As described above, in the printed matter 106 of the present embodiment, since the base material layer 1 has an affinity for the active energy ray curable resin and the ink layer 4 contains the active energy ray curable resin, the adhesion between the base material layer 1 and the ink layer 4 can be enhanced.

[0216] <Use> The printed matter 106 can be used for the same applications as the printed matter 101 of the first embodiment.

[0217] [Embodiment 7] FIG. 8 is a cross-sectional view schematically showing the layer structure of the printed matter of the seventh embodiment of the present invention. The printed matter 107 shown in FIG. 8 is a laminate formed by offset printing for surface printing. The printed matter 107 includes, in this order from the upper side (surface side), a modified layer 3, an ink layer 4, a base material layer 1, an adhesive layer 7, and a sealant layer 2.

[0218] The printed material 107 has the same configuration as the printed material 106, except that a sealant layer 2 is provided on the opposite side of the ink layer 4 in the base material layer 1 via an adhesive layer 7. The base material layer 1, ink layer 4, and modified layer 3 of the printed material 107 have the same configuration as those described in the sixth embodiment, the adhesive layer 7 has the same configuration as described in the third embodiment, and the sealant layer 2 has the same configuration as described in the second embodiment. The printing method and the method of irradiation with active energy rays can also be the same as those of the sixth embodiment.

[0219] By further providing a sealant layer 2 via an adhesive layer 7 on the side of the modified layer 3 opposite to the ink layer 4, the printed material 107 can be protected on one side by the modified layer 3 while the sealant layer 2 on the other side can be subjected to heat sealing.

[0220] In printed material 107, the content of the same type of resin (for example, polyethylene, etc.) may be 90% by mass or more. In this case, printed material 107 can be constructed as a highly recyclable monomaterial. Alternatively, even in the case of olefin resins, from the viewpoint of recycling, a monoolefin structure may be adopted in which the sealant layer 2 contains polyethylene and the base layer 1 contains polypropylene, for example, resins that are not identical but belong to the olefin family, in a composition of 90% by mass or more.

[0221] As described above, the printed material 107 of this embodiment can improve the adhesion between the substrate layer 1 and the ink layer 4. Furthermore, the effects of including the sealant layer 2 can be achieved.

[0222] <Application> The printed material 107 can be used for the same purposes as the printed material 101 of the first embodiment and the printed material 102 of the second embodiment. When the printed material 107 is used in packaging such as a laminate tube as in the second embodiment, for example, a second sealant layer (not shown) is further laminated on the upper side of the base material layer 1 (i.e., the ink layer 4 side of the base material layer 1) in the printed material 107 of Figure 8. This printed material 107 comprises, from the top (surface side), a modified layer 3, an ink layer 4, a second sealant layer, a base material layer 1, an adhesive layer 7, and a sealant layer (first sealant layer) 2 in this order. This laminate tube can be formed in the same way as the laminate tube of the second embodiment, and the first sealant layer and the second sealant layer can also have the same configuration as the laminate tube of the second embodiment.

[0223] [Print media] The inventors have found the following regarding the adhesion between the substrate layer and the ink layer. Specifically, when active energy rays are irradiated onto the ink printed on the substrate layer, the active energy rays irradiate not only the ink layer but also the substrate layer. Conventionally, it was thought that as the irradiation dose of active energy rays increases, the crosslinking density between the resin constituting the substrate layer and the resin contained in the ink increases. According to this idea, the greater the irradiation dose, the higher the adhesion between the substrate layer and the ink layer. Furthermore, the strength of the printed material is also increased.

[0224] However, the inventors have found that increasing the irradiation dose does not necessarily lead to a proportional increase in adhesion, strength, flexibility, etc. In fact, if the irradiation dose is too high, there is a tendency for the crosslinking density to decrease, resulting in a decrease in adhesion, strength, and flexibility.

[0225] The reason for this is not entirely clear, but it can be inferred as follows: When using a resin that has both a crystalline portion with a crystalline structure and an amorphous portion with an amorphous structure (e.g., polyethylene (PE)) as a base layer, crosslinking tends to occur in the amorphous portion. In this case, with resins that have relatively few branched structures (e.g., high-density polyethylene (HDPE)), if the irradiation dose is too high, molecular weight reduction occurs, resulting in a decrease in adhesion and strength. On the other hand, with resins that have relatively many branched structures (e.g., linear low-density polyethylene (LLDPE)), it is inferred that crosslinking occurs between amorphous portions, and crosslinking with other layers decreases, resulting in a decrease in adhesion and strength. Thus, the fact that excessively high irradiation doses can actually have adverse effects on adhesion and strength is a previously unknown phenomenon and represents new knowledge.

[0226] The reason for this phenomenon is thought to be that by keeping the irradiation dose low, crosslinking (covalent bonding) is suppressed in the substrate layer, and weaker interactions than crosslinking, such as electrostatic interactions (ionic bonds, hydrogen bonds, dipole interactions, van der Waals forces, etc.), act between the substrate layer and the ink layer, thereby increasing the adhesion between the substrate layer and the ink layer. Furthermore, it is thought that by suppressing unnecessary crosslinking within the substrate layer, the strength and flexibility of the substrate layer are also increased.

[0227] When manufacturing packaging from offset printed materials, the ink layers laminated on the printed material require both strength and flexibility. However, increasing the hardness of the ink layer to improve strength may reduce flexibility, while increasing flexibility too much may reduce strength. Thus, strength and flexibility are mutually exclusive properties, and it was thought difficult to simultaneously increase both strength and flexibility in printed materials. However, as described above, by appropriately adjusting the irradiation conditions of the active energy rays, it is possible to improve adhesion while also increasing strength and flexibility.

[0228] [Eighth Embodiment] Figure 9 is a schematic cross-sectional view showing the layer structure of a printed material according to the eighth embodiment of the present invention. The printed material 108 shown in Figure 9 is a laminate formed by reverse offset printing. The printed material 108 comprises, from the top (front side), a protective layer 6, a substrate layer 1, an ink layer 4, a modified layer 3, and a sealant layer 2, in this order.

[0229] Printed material 108 has a configuration that is particularly preferable for achieving monomaterialization in printed material 104. Printed material 108 basically has the same configuration as printed material 104 described in the fourth embodiment, and the printing method and the irradiation method of the active energy ray can be the same as in the fourth embodiment. Supplementary explanations of the configuration of printed material 104 and more preferable configurations will be described below.

[0230] <Ink layer> The ink layer 4 imparts markings related to the contents and various patterns to the laminate. In reverse-printed materials 108, the ink layer 4 is not exposed to the outside when it becomes packaging material, thus suppressing damage and deterioration of the markings after manufacturing. By forming the ink layer 4 over the entire substrate layer 1 using light-shielding ink, the contents can be protected from light. Such a light-shielding ink layer can be produced, for example, by overprinting a chromatic ink containing white pigments and black pigments, with the proportion of black pigments to the total pigments being 3-5% by mass, on one or more white ink layers 4 formed by full-surface printing (solid printing), thereby forming a chromatic ink layer with a saturation of 1-4 in the Munsell color system. The ink layer 4 can be given light-blocking properties while freely setting its appearance by combining a light-blocking ink layer with an ink layer (image printing layer) that does not have light-blocking properties, which can be used to print patterns or characters. In this case, the image printing layer is first formed on the substrate layer 1, and then the light-blocking ink layer is formed afterward, which improves the visibility of the image. The ink layer 4 is preferably formed of biomass-derived ink. Thereby, using the printed matter 108, a packaging material with less environmental impact can be produced. The method of forming the image is not particularly limited, and various conventionally known printing methods such as gravure printing method, offset printing method, flexographic printing method, etc. can be mentioned. Among these, from the viewpoint of irradiating with an electron beam, the above-described offset printing method is preferable.

[0231] Among the inks forming the ink layer 4, as the color ink, known color inks (for example, red ink, yellow ink, blue ink, black ink, white ink) can be used.

[0232] The type of pigment contained in the color ink other than the white ink may be appropriately determined according to the color to be expressed. For example, an inorganic pigment or an organic pigment may be used as the pigment. Examples of the inorganic pigment include carbon black (soot pigment). Examples of the organic pigment include azo pigments, phthalocyanine pigments, dioxazine pigments, quinacridone pigments, isoindolinone pigments, and dye lakes. A plurality of types of pigments may be used in combination as the pigment.

[0233] Examples of the material constituting the pigment contained in the white ink include inorganic oxides such as titanium oxide, alumina, mica, lead oxide (lead white), zinc oxide, calcium carbonate, barium carbonate, barium sulfate, kaolin, potassium titanate, talc, magnesium hydroxide, natural silicic acid, and synthetic silicic acid (white carbon). Among these, from the viewpoints of hiding power and dispersibility during addition, pigments containing titanium oxide are preferably used. Titanium oxide may be of the rutile type or the anatase type. The surface of the pigment containing titanium oxide may be treated with a metal oxide such as aluminum (Al) or silicon (Si). The average particle size of the white pigment can be selected within a range that does not interfere with the object of the present disclosure.

[0234] Examples of binder resins include alkyd resins, phenolic resins, maleic acid resins, natural resins, hydrocarbon resins, polyvinyl chloride resins, polyacetic acid resins, polystyrene resins, polyvinyl butyral resins, acrylic or methacrylic resins, polyamide resins, polyester resins, polyurethane resins, epoxy resins, urea resins, melamine resins, nitrocellulose, and ethylcellulose. These can be used individually or in combination of two or more.

[0235] The ratio of pigment content to binder resin content (pigment / resin ratio) is, for example, 1.6 or less by mass ratio, preferably 0.5 to 1.6. A mass ratio (pigment / resin ratio) of 1.6 or less makes it easier to obtain a better appearance.

[0236] The ink may consist only of white ink, or only of colored inks other than white ink, or of colored inks other than white ink and colorless ink (ink without pigment). The ink forming the ink layer 4 may contain a white ink with a smaller amount of pigment compared to a white ink used for the purpose of improving light shielding and opacity (for example, a white ink in which the ratio of pigment content to binder resin content (pigment / resin ratio) is 0.5 to 1.6 by mass). From the viewpoint of reducing the number of fine cavities resulting from the gaps between pigments formed within the ink layer 4 and obtaining a better appearance, the ink does not need to contain white ink.

[0237] <Base material layer> The base layer 1 has a main base layer 10 having three layers in this order: a first skin layer 11 on the side opposite to the sealant layer 2, a core layer 12, and a second skin layer 13 on the side of the sealant layer 2, each containing polyethylene, and an inorganic oxide layer 16 following the second skin layer 13 of the main base layer 10. The base layer 1 may further have a gas barrier coating layer 17 or an anchor coat layer, as described later. The main base layer 10 does not necessarily have to include the first skin layer 11. The first skin layer 11 and the second skin layer 13 can each be the outermost layer of the main base layer 10. Since the main base layer 10 is a multilayer film that can be obtained by co-extrusion, it can also be called a co-extruded multilayer film.

[0238] From the viewpoint of achieving a better balance between printability and impact resistance, the core layer 12 and the second skin layer 13 can be laminated adjacent to each other. Similarly, from the same viewpoint, the core layer 12 and the first skin layer 11 can be laminated adjacent to each other.

[0239] The main base layer 10 may include layers other than the three layers of the first skin layer 11, the core layer 12, and the second skin layer 13. For example, a resin layer may be present between the core layer 12 and the second skin layer 13, and another resin layer may be present between the first skin layer 11 and the core layer 12. The resin layer is, for example, a layer containing polyethylene and having a different composition from the core layer 12 and the second skin layer 13. The other resin layer is, for example, a layer containing polyethylene and having a different composition from the first skin layer 11 and the core layer 12. The resin layer and the other resin layer can also be called adhesive resin layers because they have the function of bonding different layers together (between the core layer and the skin layer). The main base material layer 10 may have, for example, 3, 5, 7, or more layers (preferably layers containing polyethylene).

[0240] The polyethylene content in the main base material layer 10 may be 90% by mass or more, or 95% by mass or more, based on the total amount of the main base material layer 10, from the viewpoint of achieving monomaterialization and excellent recyclability.

[0241] The main base material layer 10 may be a stretched film or an unstretched film. If the main base material layer 10 is a stretched film, it is easier to obtain a printed material 108 with good printability and impact resistance. Examples of stretched films include uniaxially oriented films and biaxially oriented films, but from the viewpoint of impact resistance, biaxially oriented films are preferred.

[0242] The thickness of the main base material layer 10 is not particularly limited and can be appropriately determined according to cost and application, taking into consideration its suitability as a packaging material and its suitability for lamination with other layers. The thickness of the main base material layer 10 may be 3 μm or more, 5 μm or more, 6 μm or more, or 10 μm or more, and may be 200 μm or less, 120 μm or less, 100 μm or less, or 40 μm or less.

[0243] (Core layer) The core layer 12 is a layer containing polyethylene. Hereinafter, the polyethylene constituting the core layer 12 will also be referred to as the first polyethylene. The content of the first polyethylene in the core layer 12 may be 90% by mass or more, 95% by mass or more, or 98% by mass or more, based on the total amount of the core layer 12, or it may be 100% by mass (an embodiment in which the core layer 12 is substantially composed of the first polyethylene). If the core layer 12 is composed of multiple polyethylenes (for example, multiple polyethylenes with different average molecular weights, densities, etc.), the mixture of the multiple polyethylenes will be referred to as the first polyethylene. The first polyethylene may be high-density polyethylene resin (HDPE).

[0244] The core layer 12 has a probe temperature drop of over 180°C, which makes it less prone to wrinkling when heat is applied and provides superior print stability (heat resistance). The probe drop temperature is a value measured by the method described below.

[0245] The higher the probe drop temperature of the core layer 12, the easier it is to achieve excellent printability. The probe drop temperature of the core layer 12 may be 185°C or higher, 190°C or higher, or 200°C or higher, from the viewpoint of reducing wrinkle formation and achieving better printability. On the other hand, the probe drop temperature of the core layer 12 may be 250°C or less, 230°C or less, or 220°C or less, from the viewpoint of impact resistance.

[0246] Probe drop temperature is a parameter related to the local thermal analysis of a material using a probe, and is obtained by measuring the upward and downward behavior of the probe. To measure probe drop temperature, an atomic force microscope (AFM) equipped with a cantilever (probe) with a heating mechanism and a nanothermal microscope is used. When the cantilever is brought into contact with the surface of a solid sample fixed to a sample stage, and a voltage is applied to the cantilever in contact mode, the sample surface expands thermally, and the cantilever rises. If the cantilever is heated further, the sample surface softens and its hardness changes significantly. As a result, the cantilever descends and sinks into the sample surface. The starting point of the rapid displacement detected at this time is the probe drop start point, and the probe drop temperature can be obtained by converting the voltage into temperature. In this method, the local probe drop temperature in the nanoscale region and near the surface can be determined.

[0247] Suitable AFMs include the MPF-3D-SA and Ztherm systems from Oxford Instruments, and the Nano Thermal Analysis series and nanoIR series from Bruker Japan. Measurements can also be performed with AFMs from other manufacturers by attaching the Nano Thermal Analysis. As for cantilevers, for example, the AN2-200 from Anasis Instruments is an example. Any cantilever that can sufficiently reflect laser light and to which voltage can be applied can be used, other than the cantilevers exemplified above.

[0248] The temperature range for measuring probe drop temperature varies depending on the material being measured. For example, a starting temperature of around 25°C (room temperature) and an ending temperature of around 400°C can be used. The temperature range for measuring probe drop temperature may also be between 25°C and 300°C.

[0249] The cantilever spring constant may be 0.1 to 3.5 N / m, and is preferably 0.5 to 3.5 N / m in order to perform measurements in both tapping mode and contact mode. In AFM, the amount of cantilever deflection is sometimes detected in units of voltage. In contact mode, the cantilever deflection changes before and after contact between the cantilever and the sample, so by keeping this change within the range of 0.1 to 3.0 V, it is possible to suppress damage to the sample surface while keeping the cantilever in contact with the sample.

[0250] The heating rate of the cantilever varies depending on the heating mechanism, but may be 0.1 to 10 V / second, and preferably 0.2 to 5 V / second. When the sample surface softens, the tip of the cantilever sinks into the sample and descends. The amount of cantilever sinks affects the detection sensitivity of the peak top of the softening curve and can be 3 to 500 nm. From the viewpoint of preventing damage to the cantilever, it is more preferable to have a sinking amount of 5 to 100 nm.

[0251] To calculate the probe drop temperature, it is necessary to create a calibration curve. In the examples described later, calibration curves were created using polycaprolactone, low-density polyethylene, polypropylene, and polyethylene terephthalate as calibration samples. The materials of the calibration samples are not limited to those listed above; any material whose thermal conductivity does not differ significantly from that of a typical polymer, and which has a melting point around 60°C, around 250°C, and in between, should be used. For example, it is also possible to use only three of the above four calibration samples—polycaprolactone, low-density polyethylene, and polyethylene terephthalate—excluding polypropylene, as the calibration samples.

[0252] A core layer 12 having a desired probe drop temperature can be obtained, for example, by adjusting the density of the first polyethylene, the melt flow rate (MFR), the stretching ratio during film formation, and the heat treatment / cooling conditions, or by applying treatments such as annealing or electron beam (EB) irradiation to the core layer 12.

[0253] The density of the first polyethylene is not particularly limited, but is 0.942 g / cm³. 3 More than 0.945g / cm 3 Above, or 0.950 g / cm³ 3 It may be greater than or equal to 0.980 g / cm³. 3 Below, 0.975g / cm 3 Below, 0.970g / cm 3 The following, or 0.965 g / cm³ 3 The following may also apply: The first polyethylene may be medium to high-density polyethylene. The density of a resin (resin film) is a value measured according to JIS Z 8837:2018.

[0254] The melt flow rate (MFR) of the first polyethylene at 190°C and a 2.16 kg load is not particularly limited, but may be 10 g / 10 min or less, 5 g / 10 min or less, 3 g / 10 min or less, or 2 g / 10 min or less, or 0.1 g / 10 min or more, 0.3 g / 10 min or more, or 0.5 g / 10 min or more. The melt flow rate of resin (resin film) is a value measured according to JIS K6921-2:2018.

[0255] The difference between the probe drop temperature of the core layer 12 and the probe drop temperature of the first skin layer 11 and / or the second skin layer 13 may be 10°C or more, 30°C or more, or 40°C or more, from the viewpoint of achieving both heat resistance and impact resistance. On the other hand, from the viewpoint of interlayer adhesion between the core layer 12 and the second skin layer 13, the difference between the probe drop temperature of the core layer 12 and the probe drop temperature of the first skin layer 11 and / or the second skin layer 13 may be 100°C or less, 70°C or less, or 50°C or less.

[0256] The thickness of the core layer 12 is not particularly limited and can be appropriately determined according to cost and application, taking into account suitability derived from the manufacturing method and equipment, and suitability for lamination with other layers. From a practical standpoint, the thickness of the core layer 12 may be 5 μm or more, 8 μm or more, 10 μm or more, 12 μm or more, or 15 μm or more, and may be 80 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less.

[0257] The thickness of the core layer 12 may be 33% or more, 40% or more, 50% or more, 55% or more, or 60% or more of the thickness of the main substrate layer 10, from the viewpoint of making it less likely for wrinkles to occur and providing better print stability. On the other hand, from the viewpoint of achieving superior impact resistance, the thickness of the core layer 12 may be 90% or less, 85% or less, or 80% or less of the thickness of the main substrate layer 10.

[0258] The thickness of the core layer 12 may be greater than the thickness of the first skin layer 11 and / or the second skin layer 13, from the viewpoint of reducing wrinkle formation and improving print stability. The thickness of the core layer 12 may be more than 1 time, 1.5 times or more, 2 times or more, or 3 times or more, than the thickness of the first skin layer 11 and / or the second skin layer 13. On the other hand, from the viewpoint of achieving superior impact resistance, the thickness of the core layer 12 may be 20 times or less, 10 times or less, or 5 times or less than the thickness of the first skin layer 11 and / or the second skin layer 13.

[0259] The first skin layer 11, the core layer 12, and the second skin layer 13 may contain resins other than polyethylene, to the extent that their recyclability is not impaired. Examples of such resins include ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, ethylene-(meth)acrylic acid copolymer, homopolypropylene resin (PP), olefin resins such as propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-α-olefin copolymer, and polybutene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; ethylene vinyl alcohol copolymer; polyamide; and various modifying resins. In addition, each layer may independently contain one or more additives. Examples of additives include crosslinking agents, antioxidants, antiblocking agents, lubricants (slip agents), ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, and pigments.

[0260] (Second skin layer) The second skin layer 13 is a layer containing polyethylene. Hereinafter, the polyethylene constituting the second skin layer 13 will also be referred to as the second polyethylene. The content of the second polyethylene in the second skin layer 13 may be 90% by mass or more, 95% by mass or more, or 98% by mass or more, based on the total amount of the second skin layer 13, and may also be 100% by mass (an embodiment in which the second skin layer 13 is substantially composed of the second polyethylene). If the second skin layer 13 is composed of multiple polyethylenes (for example, multiple polyethylenes with different average molecular weights, densities, etc.), the mixture of the multiple polyethylenes will be referred to as the second polyethylene. The second polyethylene may be medium-density polyethylene resin (MDPE).

[0261] The second skin layer 13 is preferable to have a probe temperature drop of 180°C or less, from the viewpoint of improving adhesion with other layers to which it is laminated and thereby achieving physical resistance to external impacts such as drops.

[0262] The probe drop temperature of the second skin layer 13 may be 170°C or less, 160°C or less, or 150°C or less, from the viewpoint of having excellent impact resistance as described above. On the other hand, the probe drop temperature of the second skin layer 13 may be 90°C or higher, 110°C or higher, or 130°C or higher, from the viewpoint of printability.

[0263] A second skin layer 13 having a desired probe drop temperature can be obtained, for example, by adjusting the density of the second polyethylene, the melt flow rate (MFR), the stretching ratio during film formation, and the heat treatment / cooling conditions, or by applying treatments such as annealing or electron beam (EB) irradiation to the second skin layer 13.

[0264] The density of the second polyethylene is not particularly limited, but is 0.926 g / cm³. 3 More than 0.930g / cm 3 More than 0.935g / cm 3 Above, or 0.940 g / cm³ 3 It may be greater than or equal to 0.970 g / cm³. 3 Below, 0.965g / cm 3 The following, or 0.960 g / cm³ 3 The following may also apply: The second polyethylene may be low-to-medium density polyethylene.

[0265] The melt flow rate (MFR) of the second polyethylene at 190°C and a 2.16 kg load is not particularly limited, but may be 15 g / 10 min or less, 10 g / 10 min or less, 5 g / 10 min or less, or 3 g / 10 min or less, or 0.5 g / 10 min or more, 0.8 g / 10 min or more, or 1 g / 10 min or more.

[0266] The thickness of the second skin layer 13 is not particularly limited and can be appropriately determined according to cost and application, taking into account suitability derived from the manufacturing method and equipment, and suitability for lamination with other layers. From a practical standpoint, the thickness of the second skin layer 13 may be 0.3 μm or more, 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more, and may be 50 μm or less, 30 μm or less, 20 μm or less, or 10 μm or less.

[0267] (First skin layer) The first skin layer 11 may be a layer containing polyethylene. The first skin layer 11 may contain a second polyethylene, for example, similar to the second skin layer 13. As described above, the main substrate layer 10 does not necessarily have to have the first skin layer 11, but including the first skin layer 11 makes it easier to improve the film formation stability during film manufacturing.

[0268] The probe drop temperature of the first skin layer 11 may be 180°C or less, 160°C or less, or 150°C or less, from the viewpoint of film formation properties and impact resistance. On the other hand, the probe drop temperature of the first skin layer 11 may be 100°C or higher, 120°C or higher, or 130°C or higher, from the viewpoint of heat resistance.

[0269] The first skin layer 11 may be a layer containing polypropylene from the viewpoint of heat resistance and film-forming properties. In this case, the probe drop temperature of the first skin layer 11 may be 200 to 260°C.

[0270] The thickness of the first skin layer 11 is not particularly limited and can be appropriately determined according to cost and application, taking into account suitability derived from the manufacturing method and equipment, and suitability for lamination with other layers. From a practical standpoint, the thickness of the first skin layer 11 may be 0.3 μm or more, 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more, and may be 50 μm or less, 30 μm or less, 20 μm or less, or 10 μm or less.

[0271] The main base material layer 10 can be manufactured by known co-extrusion methods such as the air-cooled inflation method, the water-cooled inflation method, or the T-die-casting method. From the viewpoint of versatility, the main base material layer 10 may be manufactured by the inflation method or by the air-cooled inflation method. The air-cooled inflation method is a method of continuously molding by extruding material into a tube shape using a mold with an annular lip called a ring die (or crosshead die) installed at the tip of an extruder. More specifically, an air hole is installed in the center of the ring die, compressed air is blown in through the air hole to inflate the tube, and the laminate can be manufactured by cooling it while pulling it with a roll called a pinch roll and winding up the film.

[0272] The obtained main substrate layer 10 may be subjected to surface modification treatment as needed to improve suitability for subsequent processes. For example, the surface of the laminate may be modified to improve printability or lamination suitability during lamination. Examples of modification treatments include treatments that generate functional groups by oxidizing the film surface, such as corona discharge treatment, plasma treatment, and flame treatment, and modification treatments by wet processes that form an easily adhesive layer by coating.

[0273] (Inorganic oxide layer) The inorganic oxide layer 16 contains an inorganic oxide. Examples of inorganic oxides include aluminum oxide, silicon oxide, tin oxide, magnesium oxide, and mixtures thereof. From the viewpoint of maintaining gas barrier properties more easily after heat sterilization treatment, having superior heat resistance, and transparency, the inorganic oxide layer 16 may contain one or more selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide.

[0274] The thickness of the inorganic oxide layer 16 may be 5 to 150 nm. If the thickness of the inorganic oxide layer 16 is 5 nm or more, it is easy to form a uniform layer with sufficient thickness, and sufficient gas barrier properties can be achieved. If the thickness of the inorganic oxide layer 16 is 150 nm or less, flexibility can be imparted to the inorganic oxide layer 16, and even if external loads such as bending or pulling are applied after the inorganic oxide layer 16 is formed, it is possible to suppress the occurrence of cracks in the inorganic oxide layer 16. The thickness of the inorganic oxide layer 16 may be 6 nm or more, or 8 nm or more, or 100 nm, or 50 nm or less.

[0275] The inorganic oxide layer 16 can be formed by a conventional vacuum deposition method. It can also be formed by other thin-film formation methods such as sputtering, ion plating, or plasma vapor deposition (CVD). From the viewpoint of superior productivity, the inorganic oxide layer 16 may be formed by vacuum deposition.

[0276] As a heating method for vacuum deposition, any of the following methods can be used: electron beam heating, resistance heating, or induction heating. From the viewpoint of the wide range of selectivity of the evaporation material, the vacuum deposition method may also be electron beam heating. From the viewpoint of improving the adhesion between the main substrate layer 10 (here, for example, the second skin layer 13) and the inorganic oxide layer 6, and the density of the inorganic oxide layer 16, deposition may be carried out by plasma-assisted deposition, ion beam-assisted deposition, etc. From the viewpoint of improving the transparency of the inorganic oxide layer 16, deposition may be carried out by reaction deposition.

[0277] (Gas barrier coating layer) The gas barrier coating layer 17 is a layer provided on the inorganic oxide layer 16 for the purpose of protecting the inorganic oxide layer 16 and complementing its gas barrier properties.

[0278] The gas barrier coating layer 17 may be a heat-cured product of a composition containing at least one of a water-soluble polymer and its hydrolysate, and one or more selected from the group consisting of metal alkoxides, silane coupling agents, and their hydrolysates.

[0279] Examples of water-soluble polymers include hydroxyl group-containing polymer compounds such as polyvinyl alcohol, polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, and sodium alginate. From the viewpoint of excellent gas barrier properties, the water-soluble polymer may also be polyvinyl alcohol (PVA).

[0280] Examples of metal alkoxides include compounds represented by the following general formula. M(OR 11 ) m (R 12 ) n-m ...(1) In the above equation (1), R 11 and R 12 These are each independently monovalent organic groups having 1 to 8 carbon atoms. 11 and R 12 Each of these may independently be an alkyl group such as a methyl group or an ethyl group. M represents an n-valent metal atom such as Si, Ti, Al, or Zr. m is an integer from 1 to n. Note that R 11 and R 12 If there are multiple instances, R 11 Doushi or R 12 They may be the same or they may be different.

[0281] Examples of metal alkoxides include tetraethoxysilane [Si(OC2H5)4] and triisopropoxyaluminum [Al(O-2'-C3H7)3]. From the viewpoint of being relatively stable in aqueous solvents after hydrolysis, the metal alkoxide may be tetraethoxysilane or triisopropoxyaluminum.

[0282] Examples of silane coupling agents include compounds represented by the following general formula. Si(OR 21 ) p (R 22 ) 3-p R 23 ...(2) In equation (2) above, R 21R represents an alkyl group such as a methyl group or an ethyl group. 22 R represents a monovalent organic group such as an alkyl group, an aralkyl group, an aryl group, an alkenyl group, an alkyl group substituted with an acryloxy group, or an alkyl group substituted with a methacryloxy group. 23 indicates a monovalent organic functional group, and p is an integer from 1 to 3. 21 or R 22 If there are multiple instances, R 21 Doushi or R 22 They may be the same or they may be different. 23 Examples of monovalent organic functional groups represented by include monovalent organic functional groups containing glycidyloxy groups, epoxy groups, mercapto groups, hydroxyl groups, amino groups, alkyl groups substituted with halogen atoms, and isocyanate groups.

[0283] Examples of silane coupling agents include vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, and 3-isocyanatealkylalkoxysilane.

[0284] The silane coupling agent may be a polymer such as a dimer or trimer of the silane coupling agent described above. A trimer is preferred as the polymer, and an example is 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate. This is a condensed polymer of 3-isocyanate alkylalkoxysilane. By adding 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate to a water-soluble polymer, the water resistance of the gas barrier coating layer can be improved by hydrogen bonding.

[0285] The gas barrier coating layer 17 can be formed using, for example, a composition (hereinafter referred to as "overcoat agent") obtained by adding a water-soluble polymer and a metal alkoxide and / or silane coupling agent to water or a water / alcohol mixture. The overcoat agent can be prepared, for example, by mixing a solution obtained by dissolving a hydroxyl group-containing polymer compound, which is a water-soluble polymer, in an aqueous solvent (water or water / alcohol mixture) with a metal alkoxide and / or silane coupling agent, either directly or after prior treatment such as hydrolysis of these agents. Additives such as isocyanate compounds, dispersants, stabilizers, viscosity modifiers, and colorants may be added to the overcoat agent.

[0286] The gas barrier coating layer 17 may be a film containing a polyvalent metal salt of polycarboxylic acid, which is a reaction product of the carboxyl group of the polycarboxylic acid polymer and a polyvalent metal compound (polyvalent metal salt film of polycarboxylic acid). The polyvalent metal salt film of polycarboxylic acid can be formed by applying a mixed solution of the polycarboxylic acid polymer and the polyvalent metal compound to the surface of the inorganic oxide layer 16 (or, if the inorganic oxide layer 16 is not present, the main substrate layer 10 (here, for example, the second skin layer 13)) and heating and drying it. Alternatively, a polyvalent metal salt film of polycarboxylic acid may be formed by applying a coating solution mainly composed of a polycarboxylic acid polymer to the surface of the inorganic oxide layer 16 (or, if the inorganic oxide layer 16 is not present, the main substrate layer 10 (here, for example, the second skin layer 13)), drying it to form a film, then applying a coating solution mainly composed of a polyvalent metal compound on that film, drying it to form a film, and then crosslinking these films together.

[0287] Polycarboxylic acid polymers are polymers that have two or more carboxyl groups in their molecule. Examples of polycarboxylic acid polymers include polymers of ethylenically unsaturated carboxylic acids, copolymers of ethylenically unsaturated carboxylic acids with other ethylenically unsaturated monomers, and acidic polysaccharides that have carboxyl groups in their molecule, such as alginic acid, carboxymethylcellulose, and pectin.

[0288] Examples of ethylenically unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of ethylenically unsaturated monomers copolymerizable with ethylenically unsaturated carboxylic acids include ethylene, propylene, vinyl carboxylates such as vinyl acetate, alkyl acrylates, alkyl methacrylates, alkyl itaconates, vinyl chloride, vinylidene chloride, styrene, acrylamide, and acrylonitrile. One or more polycarboxylic acid polymers may be used.

[0289] As a polymer of ethylenically unsaturated carboxylic acid, from the viewpoint of excellent gas barrier properties, it is preferable that the polymer contains structural units derived from one or more monomers selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, itaconic acid, fumaric acid, and crotonic acid, and more preferably a polymer containing structural units derived from one or more monomers selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, and itaconic acid.

[0290] In polymers of ethylenically unsaturated carboxylic acids, the proportion of constituent units derived from one or more monomers selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, and itaconic acid is preferably 80 mol% or more, and more preferably 90 mol% or more, based on the total amount of monomers in the polymer.

[0291] The number-average molecular weight of the polycarboxylic acid polymer is preferably 2,000 to 10,000,000, and more preferably 5,000 to 1,000,000. A number-average molecular weight of 2,000 or more ensures that the gas barrier coating layer 17 has sufficient water resistance, suppressing deterioration of gas barrier properties, transparency, and whitening due to moisture. A number-average molecular weight of 10,000,000 or less prevents the viscosity of the coating solution from becoming too high when forming the gas barrier coating layer 17, making it easier to form the film.

[0292] The amount of metal alkoxide in the overcoat agent can be 1 to 4 parts by mass, and may be 2 to 3 parts by mass, per 1 part by mass of water-soluble polymer, from the viewpoint of adhesion to the inorganic oxide layer 16 and maintaining gas barrier properties. Similarly, the amount of silane coupling agent can be 0.01 to 1 part by mass, and may be 0.1 to 0.5 parts by mass, per 1 part by mass of water-soluble polymer. When a silane compound (alkoxysilane) is used as the metal alkoxide, the amount of silane compound (metal alkoxide and silane coupling agent) in the overcoat agent can be 1 to 4 parts by mass, and may be 2 to 3 parts by mass, per 1 part by mass of water-soluble polymer.

[0293] The overcoat agent can be applied to the inorganic oxide layer 16 by methods such as dipping, roll coating, gravure coating, reverse gravure coating, air knife coating, comma coating, die coating, screen printing, spray coating, and gravure offset. The coating film obtained by applying the overcoat agent can be dried by methods such as hot air drying, hot roll drying, high-frequency irradiation, infrared irradiation, UV irradiation, or a combination thereof.

[0294] The temperature used to dry the coating film can be, for example, 50 to 150°C, and preferably 70 to 100°C. By keeping the drying temperature within the above range, the occurrence of cracks in the inorganic oxide layer 16 and the gas barrier coating layer 17 can be further suppressed, and excellent barrier properties can be achieved.

[0295] The gas barrier coating layer 17 may be formed using an overcoat agent containing a water-soluble polymer (e.g., a polyvinyl alcohol-based resin) and a silane compound. Acid catalysts, alkali catalysts, photopolymerization initiators, etc., may be added to the overcoat agent as needed. Examples of silane compounds include silane coupling agents, polysilazanes, and siloxanes. Specifically, examples include tetramethoxysilane, tetraethoxysilane, glycidoxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, and hexamethyldisilazane.

[0296] The gas barrier coating layer 17 described above can maintain excellent gas barrier properties even after heat sterilization. Therefore, when printed material 108 is used as packaging material for heat sterilization, the packaging material maintains excellent adhesion even after heat sterilization. Furthermore, the gas barrier coating layer 17 described above is preferable because it has sufficient transparency, flexibility, and stretch resistance, and does not pose a risk of generating harmful substances such as dioxins.

[0297] The thickness of the gas barrier coating layer 17 may be 0.05 μm or more, or 0.1 μm or more, from the viewpoint of excellent gas barrier properties. The thickness of the gas barrier coating layer 17 may be 1 μm or less, or 0.5 μm or less, from the viewpoint of easily forming a uniform coated surface, reducing the load due to drying, flexibility, and manufacturing cost.

[0298] (Anchor coat layer) From the viewpoint of improving the adhesion between the main substrate layer 10 (here, for example, the second skin layer 13) and the inorganic oxide layer 16, an anchor coat layer may be provided between the main substrate layer 10 (here, for example, the second skin layer 13) and the inorganic oxide layer 16.

[0299] The anchor coat layer can be formed using a coating solution containing a resin, such as an acrylic resin, epoxy resin, acrylic urethane resin, polyester polyurethane resin, or polyether polyurethane resin. From the viewpoint of heat resistance and interlayer adhesion strength, the anchor coat layer may also be formed using a coating solution containing an acrylic urethane resin or a polyester polyurethane resin.

[0300] The method for applying the coating solution that forms the anchor coat layer may be any known coating method, including dipping, spraying, using a coater, printing press, or brush. Examples of coaters and printing presses used in these methods, as well as their coating methods, include gravure coaters such as direct gravure, reverse gravure, kiss-reverse gravure, and offset gravure, reverse roll coaters, microgravure coaters, chamber doctor coaters, air knife coaters, dip coaters, bar coaters, comma coaters, and die coaters.

[0301] There are no particular limitations on the method for drying the anchor coat layer, but examples include natural drying, drying in an oven set to a predetermined temperature, and using a dryer attached to the coater, such as an arch dryer, floating dryer, drum dryer, or infrared dryer. The drying conditions can be appropriately selected depending on the drying method; for example, when drying in an oven, drying may be done at 60-100°C for about 1 second to 2 minutes.

[0302] The thickness of the anchor coat layer may be 0.01 μm or more, 0.03 μm or more, or 0.05 μm or more, from the viewpoint of easily obtaining sufficient adhesion between layers. The thickness of the anchor coat layer may be 5 μm or less, 3 μm or less, or 2 μm or less, from the viewpoint of excellent gas barrier properties.

[0303] From the viewpoint of improving adhesion between the substrate layer 1 and the ink layer 4, the surface of the layer in contact with the ink layer 4 in the substrate layer 1 may be subjected to pretreatment such as corona treatment, plasma treatment, or flame treatment, or a coating layer such as an easy-adhesion layer may be provided.

[0304] In particular, by applying plasma treatment or corona treatment to the surface of the substrate layer 1 on the ink layer 4 side, the wettability of the surface changes. This change in wettability causes the hydroxyl groups (OH groups) of the compounds present on the surface to rise from the surface, thereby improving the adhesion between the substrate layer 1 and the ink layer 4. Furthermore, by laminating the anchor coat layer on the surface of the gas barrier coating layer 17 of the substrate layer 1 as described above, the adhesion between the substrate layer 1 and the ink layer 4 can be improved.

[0305] <Modified layer> Examples of ink modifiers for the modified layer 3 include ester-based modifiers, ether-based modifiers, and urethane-based modifiers, which may be one-component curing types or two-component curing types.

[0306] From the viewpoint of excellent gas barrier properties, the ink modifier is preferably gas barrier. Even if minute cracks occur in the inorganic oxide layer 16 or the gas barrier coating layer 17, the gas barrier modifier can fill the gaps in the cracks and compensate for them, thereby suppressing a decrease in the gas barrier properties of the printed material 108.

[0307] Gas barrier ink modifiers are modifiers that exhibit gas barrier properties after curing. Examples of gas barrier ink modifiers include epoxy adhesives and polyester / polyurethane adhesives. Specific examples of gas barrier ink modifiers include "Maxive" manufactured by Mitsubishi Gas Chemical Company, Inc. and "Paslim" manufactured by DIC Corporation.

[0308] The oxygen permeability of the gas barrier ink modifier is, for example, 150 cc / m². 2 It is preferable that the pressure be less than or equal to 100cc / m³. 2 It is more preferable that it be less than or equal to 80cc / m². 2 It is even more preferable that it be less than or equal to 50cc / m². 2It is particularly preferable that the oxygen permeability is below day·atm. By keeping the oxygen permeability within the above range, the gas barrier properties of the printed material 108 can be sufficiently improved.

[0309] Ink modifiers can be formed using solvent-type ink modifiers (ink modifiers containing organic solvents) or solvent-free ink modifiers (ink modifiers that do not contain organic solvents). These ink modifiers may be either one-component curing type or two-component curing type. Examples of these ink modifiers include urethane-based ink modifiers, epoxy-based ink modifiers, and silicone-based ink modifiers, but from the viewpoint of impact resistance, urethane-based ink modifiers are preferred, and two-component curing type urethane-based ink modifiers are particularly preferred. Furthermore, from the viewpoint of improving oxygen barrier properties, gas barrier ink modifiers are preferred, and examples of such ink modifiers include solvent-type epoxy ink modifiers. From the viewpoint of reducing environmental impact, solvent-free ink modifiers can be used.

[0310] The polyol component may be one or more selected from the group consisting of polyester polyols, polyether polyols, polyether ester polyols, and polyurethane polyols.

[0311] Polyester polyols may be, for example, esterification products of polycarboxylic acids, dialkyl esters of polycarboxylic acids, and mixtures thereof with glycol-based solvents. Polycarboxylic acids may be, for example, succinic acid, glutaric acid, isophthalic acid, terephthalic acid, adipic acid, pimelic acid, corticic acid, azelaic acid, sebatic acid, dodecanedioic acid, and dimer acids. Glycol-based solvents may be, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butylene glycol, neopentyl glycol, or 1,6-hexanediol.

[0312] The polyether polyol may be, for example, a polymer of an oxirane compound and a low molecular weight polyol. The oxirane compound may be, for example, ethylene oxide, propylene oxide, butylene oxide, or tetrahydrofuran. The low molecular weight polyol may be water, ethylene glycol, propylene glycol, trimethylolpropane, or glycerin.

[0313] The polyether ester polyol may be obtained, for example, by the reaction of a polycarboxylic acid, a dialkyl ester of a polycarboxylic acid, or a mixture thereof with a polyether polyol.

[0314] Polyurethane polyols may be, for example, reaction products of polyester polyols, polyether polyols, or polyether ester polyols with polyisocyanate monomers.

[0315] The polyisocyanate component may be an aliphatic polyisocyanate, an aromatic polyisocyanate, or a mixture thereof.

[0316] Aliphatic polyisocyanates may be, for example, polyisocyanate monomers, polyisocyanate derivatives, or polyisocyanate-terminated prepolymers. Polyisocyanate monomers may be, for example, tetramethylene diisocyanate, isopropyl diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, or trimethylhexamethylene diisocyanate. Polyisocyanate derivatives may be 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, lysine diisocyanate, or isophorone diisocyanate.

[0317] Aromatic polyisocyanates may be, for example, polyisocyanate monomers, polyisocyanate derivatives, or polyisocyanate-terminated prepolymers. Polyisocyanate monomers may be, for example, tolylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, or tetramethylxylylene diisocyanate. Polyisocyanate derivatives may be, for example, isocyanurates derived from polyisocyanate monomers. Polyisocyanate-terminated prepolymers may be difunctional polyisocyanates containing terminal isocyanate groups obtained by reacting polyisocyanate monomers with a difunctional polyol compound such as polypropylene glycol. Alternatively, polyisocyanate-terminated prepolymers may be polyfunctional polyisocyanates containing terminal isocyanate groups obtained by reacting polyisocyanate monomers with a polyol compound with three or more functions, such as trimethylolpropane.

[0318] Although the adhesive components are similar, solvent-based ink modifiers generally have higher molecular weights than solvent-free ink modifiers. Therefore, solvent-based ink modifiers offer superior initial adhesion immediately after lamination and better adhesion strength after aging and curing. Furthermore, solvent-based ink modifiers have superior resistance to the contents, which means they are less likely to experience a decrease in adhesive strength after the contents have been stored.

[0319] The ink modifier can be formed by applying the ink modifier to the ink layer 4 using methods such as bar coating, dipping, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, spray coating, or gravure offset, forming a coating film, and then drying and curing the coating film.

[0320] When using a solvent-based ink modifier, a laminated film can be obtained by applying a solvent-based adhesive to the ink layer 4 using a general dry lamination method, bonding it with the sealant layer 2, and then removing the solvent by heat drying. Heat drying can be performed using an oven, for example, under conditions of a temperature of 50-80°C, an oven length of 5-20m, and a processing speed of 50-200m / min.

[0321] Furthermore, when using a solvent-free ink modifier, a laminated film can be obtained by coating the ink layer 4 with the solvent-free ink modifier using the method described above and then bonding it to the sealant layer 2.

[0322] If the solvent-free ink modifier is, for example, a two-component curing urethane-based ink modifier, then typically, the main component containing a polyol component and the curing agent containing a polyisocyanate component are supplied separately and mixed before reaching the coating section of the laminating machine. The mixed ink modifier is supplied, for example, between the doctor roll and the metering roll, which rotate in opposite directions in the laminating machine. The supplied ink modifier is transferred from the metering roll to the coating roll and coated onto the surface of the ink layer 4 printed on the substrate layer 1 supplied between the coating roll and the impression cylinder roll.

[0323] The ink layer 4 coated with the ink modifier and the substrate layer 1 are bonded to the sealant layer 2 and wound up by a winding machine to obtain a printed material 108. The obtained printed material 108 is preferably aged at 20 to 50°C for 24 to 96 hours. Note that the doctor roll, metering roll and coating roll described above are just one example of the configuration of a laminating device, and the configuration may differ depending on the laminating device used.

[0324] In this case, it is preferable to heat metal rolls such as doctor rolls and coating rolls to melt the solvent-free ink modifier and reduce its viscosity so that it can be applied without a solvent, thereby lowering the viscosity for coating and bonding.

[0325] Therefore, it is preferable to set the heating temperature of the solvent-free ink modifier within the range of 50 to 100°C. Furthermore, it is preferable to set the heating temperature within the range of 50 to 100°C so that the viscosity of the solvent-free adhesive at the heating temperature is 200 to 2000 mPa·s. From the viewpoint of obtaining a printed material 108 having a more uniform coating appearance, it is more preferable that the heating temperature is such that the viscosity of the solvent-free ink modifier is 300 to 1500 mPa·s, and even more preferable that it is such that it is 500 to 1000 mPa·s. Furthermore, from the viewpoint of further improving the lamination strength of the printed material 108 and further suppressing the expansion and contraction of the substrate layer 1, it is more preferable that the heating temperature is such that it is 50 to 90°C, and even more preferable that it is 50 to 80°C.

[0326] In the bonding of the substrate layer 1 on which the ink layer 4 is formed with the sealant layer 2, a solvent-free ink modifier is used, thus eliminating the need for prolonged high-temperature heat drying (such as oven drying) to remove the solvent. As a result, expansion and contraction of the substrate layer 1 can be suppressed, and a printed material 108 with good dimensional stability of the image on the ink layer 4 can be obtained.

[0327] When using a solvent-type ink modifier, the temperature for drying the coating film may be, for example, 30 to 200°C, and preferably 50 to 180°C. The temperature for curing the coating film may be, for example, 20 to 70°C, and preferably 30 to 60°C. By keeping the drying and curing temperatures within the above ranges, the occurrence of cracks in the ink layer 4 and the modified layer 3 can be suppressed, and the gas barrier properties of the printed material 108 can be sufficiently improved.

[0328] The thickness of the modified layer 3 is preferably 0.1 to 20 μm, more preferably 0.5 to 10 μm, and even more preferably 1 to 5 μm. A thickness of 0.1 μm or more of the modified layer 3 provides cushioning to mitigate external impacts, thereby making it easier to suppress cracking of the inorganic oxide layer 16 and further improving the gas barrier properties of the printed material 108. A thickness of 20 μm or less of the modified layer 3 tends to adequately maintain the flexibility of the printed material 108.

[0329] <Sealant layer> The sealant layer 2 is, for example, a layer made of polyethylene. The sealant layer 2 is a layer that is joined by heat sealing when forming packaging materials such as packaging bags using printed material 108. The polyethylene constituting the sealant layer 2 may be low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), or very low-density polyethylene (VLDPE) from the viewpoint of excellent heat-sealability. From the viewpoint of environmental impact, the sealant layer 2 may be made of biomass-derived polyethylene resin or recycled polyethylene resin. The sealant layer 2 may be made of, for example, an unoriented polyethylene film.

[0330] As a low-density polyethylene, its density is 0.900 g / cm³. 3 More than 0.925g / cm 3 Polyethylene with a density of less than 0.900 g / cm³ can be used. For linear low-density polyethylene, a density of 0.900 g / cm³ is acceptable. 3 More than 0.925g / cm 3 Polyethylene with a density of less than 0.900 g / cm³ can be used. Ultra-low density polyethylene has a density of 0.900 g / cm³. 3 Polyethylene less than a certain amount can be used.

[0331] The sealant layer 2 may contain resins other than polyethylene. Examples of resins other than polyethylene include olefin resins such as ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, ethylene-(meth)acrylic acid copolymer, homopolypropylene (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-α-olefin copolymer, and polybutene. The sealant layer 2 may also contain additives such as antioxidants, lubricants, antiblocking agents, and antistatic agents.

[0332] The thickness of the sealant layer 2 may be, for example, 20 μm or more, 40 μm or more, or 50 μm or more. A thickness of 20 μm or more for the sealant layer 2 ensures sufficient heat seal strength. The thickness of the sealant layer 2 may also be, for example, 200 μm or less, 170 μm or less, or 150 μm or less. A thickness of 200 μm or less for the sealant layer 2 ensures excellent processability.

[0333] The sealant layer 2 may include a polyolefin resin, or a composition containing a polyolefin resin and a white pigment (a milky white polyolefin resin composition). The sealant layer 2 is a layer for heat sealing when forming the printed material 108 into a packaging bag, and has heat-adhesive properties.

[0334] Examples of polyolefin resins include ethylene resins, polypropylene resins, propylene resins, ethylene-propylene copolymers, ethylene-α,β unsaturated carboxylic acid copolymers, esterified products of ethylene-α,β unsaturated carboxylic acid copolymers, acid anhydride-modified polyolefins, and blends of two or more of these. Among these, polypropylene resins (especially CPP: unstretched polypropylene resins) are particularly preferred because they have excellent thermal adhesion, as well as heat resistance and oil resistance.

[0335] Examples of ethylene-based resins include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), and ethylene-α-olefin copolymers.

[0336] Examples of polypropylene resins include homopolypropylene, block polypropylene, and random polypropylene.

[0337] Examples of propylene-based resins include propylene-α-olefin copolymers.

[0338] Examples of ethylene-α,β unsaturated carboxylic acid copolymers include ethylene-acrylic acid copolymers and ethylene-methacrylic acid copolymers.

[0339] Examples of acid anhydride-modified polyolefins include ethylene-maleic anhydride graft copolymers and terpolymers such as ethylene-ethyl acrylate-maleic anhydride.

[0340] Examples of materials constituting white pigments include inorganic oxides such as titanium dioxide, alumina, mica, lead oxide (lead white), zinc oxide, calcium carbonate, barium carbonate, barium sulfate, kaolin, potassium titanate, talc, magnesium hydroxide, natural silicic acid, and synthetic silicic acid (white carbon). Among these, pigments containing titanium dioxide are preferred from the viewpoint of opacity and dispersibility when added. The titanium dioxide may be of the rutile or anatase form. The surface of the pigment containing titanium dioxide may be treated with a metal oxide such as aluminum (Al) or silica (Si). The average particle size of the white pigment can be selected within a range that does not hinder the objectives of the present invention.

[0341] If the sealant layer 2 contains a white pigment, the polyolefin resin content may be 90% by mass or more, 92% by mass or more, or 94% by mass or more, based on the total mass of the sealant layer 2 (total mass of the milky white polyolefin resin composition), from the viewpoint of thermal adhesion. The polyolefin resin content may be 97% by mass or less, 96% by mass or less, or 95% by mass or less, based on the total mass of the sealant layer 2, from the viewpoint of light shielding and opacity. From these viewpoints, the polyolefin resin content may be 90 to 97% by mass, based on the total mass of the sealant layer 2.

[0342] If the sealant layer 2 contains a white pigment, the content of the white pigment may be 3% by mass or more, 4% by mass or more, or 5% by mass or more, based on the total mass of the sealant layer 2 (total mass of the milky white polyolefin resin composition), from the viewpoint of light shielding and opacity. From the viewpoint of heat adhesion, the content of the white pigment may be 10% by mass or less, 8% by mass or less, or 6% by mass or less, based on the total mass of the sealant layer 2. From these viewpoints, the content of the white pigment may be 3 to 10% by mass, based on the total mass of the sealant layer 2.

[0343] The ratio of the white pigment content to the polyolefin resin content (pigment / resin ratio) may be 0.04 to 0.1 by mass, and may also be 0.04 to 0.08 or 0.05 to 0.06.

[0344] The sealant layer 2 may contain other additives as needed. Examples of other additives include antioxidants, slip agents, antiblocking agents, and weather-resistant agents.

[0345] The sealant layer 2 may be a single layer or a multilayer structure. When the sealant layer 2 contains a white pigment, and the sealant layer 2 is a multilayer structure, all constituent layers are layers containing polyolefin resin, and for example, at least one of these layers may be a layer containing a milky white polyolefin resin composition. In that case, it is preferable that the layer containing the milky white polyolefin resin composition is located on the ink layer 4 side. Also, for example, when the sealant layer 2 has a three-layer structure consisting of an outer layer / intermediate layer / outer layer, it is preferable that the intermediate layer is a layer containing a milky white polyolefin resin composition. The polyolefin resins used in each layer may be the same or different.

[0346] When a white pigment is included, the thickness of the sealant layer 2 is not particularly limited and can be set appropriately according to the desired properties. In this case, the thickness of the sealant layer 2 may be, for example, 15 to 200 μm, 30 to 200 μm, or 50 to 200 μm. By increasing the thickness of the sealant layer 2, sufficient opacity and light shielding can be ensured while keeping the concentration of the white pigment low.

[0347] As described above, the sealant layer 2 may be a layer consisting of one or more types of sealant films. The sealant film may be, for example, an unoriented resin film. The method for forming the sealant film is not particularly limited, and known methods such as the inflation method and melt molding methods such as the T-die extrusion method are preferably used.

[0348] When sealant layer 2 contains a white pigment, a masterbatch in which the white pigment is pre-mixed into the polyolefin resin may be used when forming the sealant film. The white pigment concentration of the masterbatch may be, for example, about 40 to 70% by mass. When using a masterbatch, the desired blending ratio may be adjusted by kneading the masterbatch with the polyolefin resin.

[0349] <Protective layer> In this embodiment, a heat-resistant layer is used as the protective layer 6. The heat-resistant layer is provided to prevent defects when heat-sealing during bag making and filling / sealing, and to ensure suitability for heat sealing. Specifically, it can suppress cosmetic defects such as wrinkles when the base material layer 1 and the heat seal bar come into contact, and the occurrence of adhesion (detachment) of the base material layer 1 to the heat seal bar due to heat welding. Furthermore, when using printed material 108 in a standing pouch-shaped packaging bag, it can suppress the occurrence of heat welding between the base material layers 1 when the bottom seal is performed with the base material layers 1 facing each other at the bottom. For these reasons, the heat-resistant layer is provided as the outermost layer of the printed material 108.

[0350] The thickness of the heat-resistant layer is adjusted according to the total thickness of the printed material 108, but from the viewpoint of improving heat resistance and reducing the amount of heat required for heat sealing, it may be, for example, 0.1 to 5.0 μm, 0.2 to 4.0 μm, or 0.3 to 2.0 μm.

[0351] The heat-resistant layer provided on the outer surface of the base layer 1 must have heat resistance such that it does not soften, melt, or decompose even when heated to, for example, 140°C during heat sealing. Therefore, the heat-resistant layer preferably contains a thermosetting resin or a resin with a melting point of 160°C or higher. The resin is preferably one or more resins selected from the group consisting of polyacrylic, polyurethane, polyester, polyamide, polyamide-imide, vinyl chloride-vinyl acetate copolymer, and epoxy. Among these, acrylic resins, urethane resins, vinyl chloride-vinyl acetate copolymers, polyester resins, and mixtures thereof are more preferred.

[0352] To form urethane bonds, a two-component curable resin is preferred. The curing agent is not particularly limited as long as it reacts with the two-component curable resin and can be cured, but polyvalent isocyanate compounds are preferred. Examples include aromatic diisocyanate compounds such as tolylene diisocyanate and 4,4-diphenylmethane diisocyanate, aliphatic diisocyanate compounds such as xylylene diisocyanate and hexamethylene diisocyanate, polymers thereof, and derivatives thereof.

[0353] The heat-resistant layer may contain matting agents. By including matting agents in the heat-resistant layer, heat resistance can be improved and slipperiness can be adjusted. Examples of matting agents include inorganic particles. Examples of inorganic particles include silica, talc, calcium carbonate, precipitated barium sulfate, alumina, acid clay, clay, magnesium carbonate, carbon black, tin oxide, titanium white, mica, and glass.

[0354] The heat-resistant layer may contain waxes such as polyethylene wax, polypropylene wax, polytetrafluoroethylene wax, montan wax, paraffin wax, microcrystalline wax, amide wax, and petroleum wax, as well as lubricants such as liquid paraffin, white petrolatum, and castor oil. The inclusion of a lubricant in the heat-resistant layer provides appropriate slipperiness to the printed material 108 during drying, thereby improving the efficiency of packaging material production.

[0355] The heat-resistant layer can be formed by applying a heat-resistant coating solution. The amount of heat-resistant coating solution applied after drying is 0.1 to 5 g / m². 2 Preferably, it is 0.3 to 3 g / m 2 It is more preferable that the amount applied is within the above numerical range, which reduces residual solvent and suppresses blocking during film formation.

[0356] The method of applying the heat-resistant coating liquid is not particularly limited, and coating methods such as roll coating, gravure coating, knife coating, dip coating, and spray coating can be used.

[0357] Suitable solvents include, for example, alcohol-based solvents such as methanol, ethanol, isopropyl alcohol, n-butyl alcohol, and isobutyl alcohol; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as ethyl acetate, n-propyl acetate, n-butyl acetate, and isobutyl acetate; glycol-based solvents such as 2-butoxyethanol and propylene glycol monomethyl ether; and hydrocarbon-based solvents such as toluene, xylene, n-hexane, and methylcyclohexane.

[0358] When applying and drying (curing) a heat-resistant coating liquid to form a heat-resistant layer, an adhesion-enhancing layer may be provided on the base layer 1 to improve the adhesion between the base layer 1 and the heat-resistant layer, to the extent that it does not impair recyclability.

[0359] In printed material 108, the content of the same type of resin (polyethylene) may be 90% by mass or more. In this case, printed material 108 can be constructed as a highly recyclable monomaterial. Alternatively, even in the case of olefin resins, from the viewpoint of recycling, a monoolefin structure may be adopted in which, for example, polyethylene is used in the sealant layer 2 and polypropylene is used in the base layer 1, containing 90% by mass or more of resins that are not identical but belong to the olefin family.

[0360] As described above, the printed material 108 of this embodiment provides the same effects as the printed material 104 of the fourth embodiment. In addition, it also provides barrier properties due to the substrate layer 1.

[0361] When recycling printed materials such as printed material 108, there is a risk that the ink in the ink layer may penetrate into the modified layer. Normally, the layers laminated on the base layer are dissolved with a solvent, leaving only the base layer, and then the components dissolved in the solvent need to be decolorized (deinked). However, if ink penetrates into the transparent modified layer, it will be treated as recycled resin, which is disadvantageous for recycling, so it is desirable that the ink does not penetrate into the modified layer. In this regard, in the present invention, the ink layer 4 is instantly hardened by irradiation with active energy rays, and excessive penetration of the ink into the modified layer (penetration far exceeding the amount necessary to improve adhesion) is suppressed, thus improving recyclability and making it possible to omit the deinking process. Furthermore, in the present invention, the adhesion between the substrate layer 1 and the ink layer 4 is enhanced by irradiation with active energy rays. However, from the viewpoint of improving recyclability (peeling the ink layer 4 from the substrate layer 1), it is preferable that the adhesion between the substrate layer 1 and the ink layer 4 is not excessively high, and it is also preferable to set the irradiation dose of the active energy rays to 100 kGy or less.

[0362] <Application> The printed material 108 can be used for the same purposes as the printed material 104 of the fourth embodiment. Furthermore, the printed material 108 can be used as packaging material for packaging bags, etc. Specifically, it can be used as packaging material for flat bags, three-sided bags, gusseted bags, standing pouches, spout pouches, beak pouches, etc. Packaging material made from the printed material 108 is said to be highly recyclable, free from (or with minimal) distortion of the design, and highly impact-resistant.

[0363] Furthermore, in the printed material 108, the ink layer 4 is provided in a position visible from the outside of the printed material 108 for the purpose of displaying information about the contents, identifying the contents, or improving the design of the packaging bag.

[0364] Furthermore, although this embodiment describes the case where the main component of the base layer 1 is polyethylene, the same method can be applied to other cases where the main component of the base layer 1 is other polyolefins, nylon, etc.

[0365] [Ninth Embodiment] Figure 10 is a schematic cross-sectional view showing the layer structure of a printed material according to the ninth embodiment of the present invention. The printed material 109 shown in Figure 10 is a laminate formed by reverse offset printing. The printed material 109 comprises, from the top (front side), a protective layer 6, a substrate layer 1, an ink layer 4, a modification layer 3, a barrier layer 5, an adhesive layer 7, and a sealant layer 2, in this order.

[0366] The printed material 109 has the same configuration as the printed material 108, except that the base layer 1 comprises only the main base layer 10, and further comprises a barrier layer 5 and an adhesive layer 7. Also, like the printed material 108, the printed material 109 has a configuration that is particularly preferable for achieving monomaterialization. The ink layer 4, modified layer 3, and sealant layer 2 of the printed material 109 have the same configuration as those described in the eighth embodiment, and the printing method and the irradiation method of the active energy rays can also be the same as those in the eighth embodiment.

[0367] <Base material layer> The base layer 1 comprises a main base layer 10 similar to that of the printed material 108. Since the configuration of the main base layer 10 is the same as in the eighth embodiment, a detailed explanation is omitted. The base layer 1 may also have an inorganic oxide layer 16, a gas barrier coating layer 17, etc., similar to those in the eighth embodiment.

[0368] <Barrier layer> The barrier layer 5 has a gas barrier layer 52 and a barrier substrate layer 51 in that order, starting from the modified layer 3 side. The barrier substrate layer 51 has the same configuration as the main substrate layer 10 in the substrate layer 1 of the printed material 108. Specifically, the barrier substrate layer 51 has a first skin layer 511, a core layer 512, and a second skin layer 513, similar to the first skin layer 11, core layer 12, and second skin layer 13 of the main substrate layer 10, respectively. The gas barrier layer 52 has an anchor coat layer 521 and an inorganic oxide layer 522, similar to the anchor coat layer and inorganic oxide layer 16 in the substrate layer 1 of the printed material 108, respectively. In the barrier layer 5, the first skin layer 511, core layer 512, second skin layer 513, anchor coat layer 521, and inorganic oxide layer 522 are laminated in this order. Furthermore, the gas barrier layer 52 may have a gas barrier coating layer similar to the gas barrier coating layer of the substrate layer 1 in the printed material 108. For this reason, a detailed explanation of the barrier layer 5 is omitted.

[0369] <Adhesive layer> The adhesive layer 7 may be the same as the adhesive layer 7 of the printed material 103 in the third embodiment. Preferably, the adhesive layer 7 is a layer formed from a gas barrier adhesive.

[0370] In printed material 109, the content of the same type of resin (polyethylene) may be 90% by mass or more. In this case, printed material 109 can be constructed as a highly recyclable monomaterial. Alternatively, even in the case of olefin resins, from the viewpoint of recycling, a monoolefin structure may be adopted in which, for example, polyethylene is used in the sealant layer 2 and polypropylene is used in the base layer 1, containing 90% by mass or more of resins that are not identical but belong to the olefin family.

[0371] As described above, the printed material 109 of this embodiment provides the same effects as the printed material 104 of the fourth embodiment. In addition, it also provides barrier properties due to the barrier layer 5.

[0372] <Application> The printed material 109 can be used for the same purposes as the printed material 108 of the eighth embodiment.

[0373] [Tenth Embodiment] Figure 11 is a schematic cross-sectional view showing the layer structure of a printed material according to the tenth embodiment of the present invention. The printed material 110 shown in Figure 11 is a laminate formed by reverse offset printing. The printed material 110 comprises, from the top (front side), a protective layer 6, a substrate layer 1, an ink layer 4, a modified layer 3, and a sealant layer 2, in this order.

[0374] The printed material 110 has the same configuration as described in the eighth embodiment, except that the configuration of the substrate layer 1 and the sealant layer 2 has been changed, and the printing method and the irradiation method of the active energy rays can be the same as in the eighth embodiment.

[0375] <Base material layer> [Polypropylene film] The base layer 1 has a main base layer 10 having three layers in this order: a first skin layer 121 on the side opposite to the sealant layer 2, a core layer 122, and a second skin layer 123 on the side of the sealant layer 2, each containing polypropylene. The main base layer 10 also has an anchor coat layer 126, a vapor deposition layer 127, and a gas barrier coating layer 128 following the second skin layer 123 in this order. The main base layer 10 does not necessarily have to include the second skin layer 123. The first skin layer 121 and the second skin layer 123 can each be the outermost layer of the main base layer 10. Since the main base layer 10 is a multilayer film that can be obtained by co-extrusion, it can also be called a co-extruded multilayer film.

[0376] The core layer 122 contains polypropylene. The first skin layer 121 contains a copolymer of propylene and other monomers. The printed material 110 having the main substrate layer 10 can be used in packaging that is subjected to heat sterilization. When the surface of the first skin layer 121 is quantitatively analyzed for elements by X-ray photoelectron spectroscopy, it is preferable that the average value of the ratio of oxygen atoms to carbon atoms (hereinafter also simply referred to as "O / C") is 0.010 to 0.050 and the standard deviation of O / C is 0.0010 to 0.0050.

[0377] The main substrate layer 10 exhibits excellent adhesion to other layers after heat sterilization, excellent adhesion stability, and does not easily reduce the wettability of other layers. The inventors believe the reason for these effects is as follows: Normally, polypropylene films are composed of carbon atoms and hydrogen atoms, resulting in low wettability to other layers and low adhesion. When the average O / C value is less than 0.01, the polypropylene film has low wettability and insufficient adhesion. When the average O / C value is greater than 0.05, as described later, when a polypropylene film is used as the substrate anchor coat layer 126, components on the surface of the polypropylene film migrate to other layers (deposition layer 127), reducing the wettability of the deposition layer 127. When a gas barrier coating layer 128 is formed on a deposition layer 127 with reduced wettability, the coating properties of the gas barrier coating layer 128 deteriorate, leading to a decrease in gas barrier properties. The surface of the first skin layer 121 of the main substrate layer 10 preferably has an average O / C ratio of 0.01 to 0.05 and a standard deviation of O / C ratio of 0.0010 to 0.0050. Furthermore, the first skin layer 121 preferably contains a copolymer of propylene and another monomer. As a result, the main substrate layer 10 has excellent adhesion to other layers after heat sterilization treatment, excellent adhesion stability, and does not easily reduce the wettability of other layers.

[0378] The main base layer 10 is a film containing polypropylene. The main base layer 10 may be, for example, a film formed by stretching polypropylene after it has been made into a sheet and then oriented uniaxially or biaxially.

[0379] Polypropylene may be crystalline polypropylene. From the viewpoint of improving heat resistance, polypropylene may also be homopolypropylene, which is a homopolymer of propylene. Polypropylene may contain, for example, a random copolymer of propylene and α-olefin.

[0380] The polypropylene content may be 90% by mass or more, 95% by mass or more, or 99% by mass or more, based on the total mass of the main base material layer 10. The polypropylene content may also be substantially 100% by mass (in the embodiment where the main base material layer 10 is made of polypropylene), based on the total mass of the main base material layer 10.

[0381] The main substrate layer 10 may contain organic additives such as antiblocking agents (AB agents), antioxidants, stabilizers, lubricants, and antistatic agents, or it may contain inorganic additives such as silica, zeolite, hydrotalcite, silica particles, and thyroid.

[0382] The antiblocking agent (AB) may be either organic or inorganic particles. Examples of organic particles include polymethyl methacrylate particles, polystyrene particles, and polyamide particles. Examples of inorganic particles include silica particles, zeolite, talc, kaolinite, and feldspar. These antiblocking agents may be used individually or in combination of two or more.

[0383] Considering antiblocking performance, it is preferable to use AB agents with an average particle size of 0.1 to 5 μm. The average particle size is the weight-average diameter measured by the coal tar method.

[0384] The thickness (total thickness) of the main substrate layer 10 is not particularly limited, but may be, for example, 3 μm to 200 μm, 6 μm to 50 μm, or 10 μm to 30 μm.

[0385] The polypropylene used in the main base layer 10 may be polypropylene polymerized from fossil fuels, recycled polypropylene, or polypropylene obtained by polymerizing biomass-derived raw materials such as plants. When using these polypropylenes, they may be used individually, or a mixture of polypropylene polymerized from fossil fuels and recycled polypropylene or polypropylene obtained by polymerizing biomass-derived raw materials such as plants may be used.

[0386] The main substrate layer 10 can also be used as one of the layers in a multilayer laminate. In this embodiment, using it as the substrate layer 1 of the printed material 110 improves adhesion with the anchor coat layer 126.

[0387] The main substrate layer 10 (or the printed material 110 including the main substrate layer 10) can be used for the same purposes as in the first embodiment and can be subjected to processing for that purpose.

[0388] The first skin layer 121, the second skin layer 123, and the core layer 122 of the main substrate layer 10 will be described below.

[0389] <First Skin Layer> The first skin layer 121 contains a copolymer of propylene and another monomer. The copolymer content may be 90% by mass or more, 95% by mass or more, or 99% by mass or more, based on the total mass of the first skin layer 121. The copolymer content may be substantially 100% by mass, based on the total mass of the first skin layer 121.

[0390] Other monomers that can be used in the copolymer include, for example, α-olefins such as ethylene, 1-butene, and 1-hexene. The first skin layer 121 may contain a copolymer of propylene and an α-olefin. The copolymer may be a random copolymer.

[0391] The propylene unit content in the copolymer may be 80 mol% or more, 90 mol% or more, 95 mol% or more, or 96 mol% or more, based on the total amount of monomer units, and may also be 99.7 mol% or less, 99.5 mol% or less, 99 mol% or less, or 98 mol% or less.

[0392] The first skin layer 121 can be formed on the core layer 122, for example, by co-extruding polypropylene forming the core layer 122 and a copolymer of propylene and other monomers forming the first skin layer 121.

[0393] The copolymer used in the first skin layer 121 may be a resin polymerized from fossil fuels, a recycled resin, or a resin obtained by polymerizing biomass-derived raw materials such as plants. When using these resins, they may be used individually, or a mixture of a resin polymerized from fossil fuels and a recycled resin or a resin obtained by polymerizing biomass-derived raw materials such as plants may be used.

[0394] The softening temperature measured from the film cross-section by local thermal analysis (LTA) of the first skin layer 121 is preferably 120°C or higher. This tends to suppress blocking with other layers (e.g., the substrate vapor deposition layer 127) and further suppress the decrease in wettability of other layers. The softening temperature measured from the film cross-section by local thermal analysis of the first skin layer 121 is preferably 170°C or lower. This tends to ensure the flexibility of the first skin layer 121 and ensure sufficient adhesion strength with the core layer 122. The softening temperature may be the temperature measured at the center of the first skin layer 121.

[0395] The thickness of the first skin layer 121 is preferably 0.1 μm or more. A thickness of 0.1 μm or more allows for uniform lamination and suppresses variations in thickness. Furthermore, it is believed that the stress on the substrate vapor deposition layer 127 during heat sterilization can be sufficiently relieved, thereby suppressing barrier degradation. From this viewpoint, the thickness of the first skin layer 121 is preferably 0.3 μm or more. On the other hand, there is no particular upper limit to the thickness of the first skin layer 121, but from the viewpoint of ensuring sufficient heat resistance of the entire main substrate layer 10, it is preferably 2.0 μm or less, and more preferably 1.8 μm or less.

[0396] The ratio of the thickness of the first skin layer 121 to the thickness of the main base material layer 10 (thickness of the first skin layer 121 / thickness of the main base material layer 10) may be 1 / 100 to 1 / 5, or 1 / 70 to 1 / 10. When the thickness ratio is within the above range, the overall heat resistance of the main base material layer 10 can be more sufficiently ensured. Furthermore, when the main base material layer 10 is used as a gas barrier layer or a laminate material, it tends to be possible to further improve the adhesion between these layers and enhance the stability of the adhesion.

[0397] (O / C) The O / C ratio preferably has an average value of 0.010 to 0.050 and a standard deviation of 0.0010 to 0.0050. The average value of the O / C ratio is more preferably 0.010 or higher, and even more preferably 0.011 or higher, particularly preferably 0.012 or higher, and even more preferably 0.015 or higher, from the viewpoint of further improving adhesion and adhesion stability. The average value of the O / C ratio is preferably 0.050 or lower, and even more preferably 0.045 or lower, even more preferably 0.040 or lower, and particularly preferably 0.030 or lower, from the viewpoint of suppressing a decrease in the wettability of other layers. The average O / C value may be 0.010 or more and 0.050 or less, 0.010 or more and 0.045 or less, 0.010 or more and 0.040 or less, 0.010 or more and 0.030 or less, 0.011 or more and 0.050 or less, 0.011 or more and 0.045 or less, 0.011 or more and 0.040 or less, 0.011 or more and 0.030 or less, 0.012 or more and 0.050 or less, 0.012 or more and 0.045 or less, 0.012 or more and 0.030 or less, 0.015 or more and 0.050 or less, 0.015 or more and 0.045 or less, 0.015 or more and 0.040 or less, or 0.015 or more and 0.030 or less.

[0398] The standard deviation of O / C is preferably 0.0010 or higher, more preferably 0.0012 or higher, even more preferably 0.0015 or higher, and particularly preferably 0.0020 or higher, from the viewpoint of further improving adhesion and adhesion stability. The standard deviation of O / C is preferably 0.0050 or lower, and tends to yield a stable surface treatment state with less variation, so it is more preferably 0.0045 or lower, even more preferably 0.0040 or lower, and particularly preferably 0.0035 or lower. The standard deviation of O / C is as follows: 0.0010 to 0.0050, 0.0010 to 0.0045, 0.0010 to 0.0040, 0.0010 to 0.0035, 0.0012 to 0.0050, 0.0012 to 0.0045, 0.0012 to 0.0040, 0.0012 to 0.0035. It may be 0.0015 or more and 0.0050 or less, 0.0015 or more and 0.0045 or less, 0.0015 or more and 0.0040 or less, 0.0015 or more and 0.0035 or less, 0.0020 or more and 0.0050 or less, 0.0020 or more and 0.0045 or less, 0.0020 or more and 0.0040 or less, or 0.0020 or more and 0.0035 or less.

[0399] The mean and standard deviation of O / C are calculated as follows. Specifically, the surface of the first skin layer 121 is subjected to narrow spectrum analysis using the following measuring instruments under the following measurement conditions. This obtains the narrow spectra of the O1s and C1s orbitals on the surface of the first skin layer 121. For each element of O and C, the elemental quantitative value (atomic %) is determined from the peak area using relative sensitivity coefficients of 1.00 eV for C1s and 2.28 eV for O1s. The O / C is calculated using the obtained elemental quantitative values. Note that the ratio of oxygen atoms to oxygen atoms (O / C) is the ratio of the number of atoms. The O / C can be measured at five randomly selected locations on the surface of the first skin layer 121. The mean and standard deviation of O / C are calculated from the measurement results of the five locations.

[0400] <Measuring equipment> JEOL Ltd. JPS-9030 Photoelectron Spectrometer <Measurement conditions: Spectrum acquisition conditions> Incident X-ray: MgKα (hν=1253.6eV) X-ray output: 100W (10kV, 10mA) Measurement area: Circular area with a diameter of 6 mm Photoelectron capture angle: 15° Dwell Time: 100ms Measurement step: 0.2eV Pass energy: 10 eV Total number of times: 5

[0401] (Second skin layer) The second skin layer 123 may contain a copolymer of propylene and other monomers. The content of the copolymer of propylene and other monomers in the second skin layer 123, the other monomers used in the copolymer, the content of propylene units in the copolymer, the method of forming the second skin layer 123, the softening temperature, and the thickness of the second skin layer 123 may be the same as those of the first skin layer 121. The ratio of the thickness of the second skin layer 123 to the thickness of the main substrate layer 10 may be the same as the ratio of the thickness of the first skin layer 121 to the thickness of the main substrate layer 10.

[0402] (Core layer) The core layer 122 contains polypropylene. From the viewpoint of improving the heat resistance of the main substrate layer 10, the polypropylene used in the core layer 122 may be crystalline polypropylene, and from the viewpoint of further improving the heat resistance for heat sterilization treatment, it may also be homopolypropylene, which is a homopolymer of propylene. However, as long as the effects of the present invention are not significantly impaired, a random copolymer of propylene and α-olefin, or a mixture of said copolymer and homopolypropylene, etc., may be used.

[0403] The polyolefin used in the core layer 122 may be polyolefin polymerized from fossil fuels, recycled polyolefin, or polyolefin obtained by polymerizing biomass-derived raw materials such as plants. When using these polyolefins, they may be used individually, or a mixture of polyolefin polymerized from fossil fuels and recycled polyolefin or polyolefin obtained by polymerizing biomass-derived raw materials such as plants may be used.

[0404] If the main substrate layer 10 comprises a first skin layer 121 and a second skin layer 123, the core layer 122, which is placed between the first skin layer 121 and the second skin layer 123, does not need to contain the AB agent.

[0405] The thickness of the core layer 122 may be 10 to 200 μm, 12 to 50 μm, or 15 to 30 μm, from the viewpoint of maintaining processability and ease of handling as the main substrate layer 10.

[0406] Here, if stretched polypropylene film (OPP film) is used as any of the first skin layer 121, core layer 122, and second skin layer 123, the heat resistance may decrease. To improve heat resistance, it is effective to use homopolypropylene, which has high heat resistance, as the material for the OPP film. On the other hand, OPP films formed from homopolypropylene tend to have weaker adhesion to adjacent layers compared to OPP films formed from other propylenes. However, by using a core layer containing homopropylene and using propylene other than homopropylene for the first skin layer 121 and second skin layer 123, the OPP film obtained by stretching the laminate of these layers exhibits excellent heat resistance and non-adhesion properties.

[0407] (Surface treatment) The surfaces of the first skin layer 121 and the second skin layer 123 of the main substrate layer 10 may be surface-treated using a conventionally known surface treatment apparatus. Examples of such surface treatments include corona treatment, plasma treatment, and flame treatment. Among these surface treatments, plasma treatment is preferred because it can be performed effectively at low temperatures and in a short time, and the degree of treatment is stable over time. Plasma treatment can be performed, for example, under atmospheric pressure and in a vacuum, and it is preferable to perform it in a vacuum in order to perform a stable treatment with a high degree of treatment. Furthermore, plasma treatment in a vacuum can be performed simultaneously with the process of forming the substrate deposition layer 127.

[0408] Conventional plasma processing equipment can be used for plasma treatment. By using such equipment, it is possible to suppress the occurrence of abnormal discharges such as arc discharges even when high power is applied, and to perform stable plasma treatment for a long period of time. The gas used for plasma treatment can be any gas that can generate plasma and is not particularly limited, but examples include argon (Ar), helium (He), nitrogen (N2), and oxygen (O2).

[0409] The base layer 1 comprises, from the main base layer 10 side, an anchor coat layer 126, a vapor deposition layer 127, and a gas barrier coating layer 128 in this order.

[0410] (Anchor coat layer) The anchor coat layer 126 is a layer that further improves the adhesion between the main substrate layer 10 and the vapor-deposited layer 127, and is provided between the main substrate layer 10 and the vapor-deposited layer 127. The material constituting the anchor coat layer 126 is not particularly limited as long as it is capable of improving the adhesion between the main substrate layer 10 and the vapor-deposited layer 127.

[0411] As the material for the anchor coat layer 126, for example, a material containing a reaction product of a polyol compound containing (meth)acrylic resin and an isocyanate compound can be used. Note that "(meth)acrylic resin" means at least one of "acrylic resin" and the corresponding "methacrylic resin".

[0412] Examples of (meth)acrylic resins include (meth)acrylic polymers obtained by polymerizing polymerizable monomers containing (meth)acrylic monomers. The (meth)acrylic polymer may be a homopolymer or a copolymer with polymerizable monomers other than (meth)acrylic monomers. The (meth)acrylic resin may be a resin that can be thermally crosslinked, such as urethane curing or epoxy curing. From the viewpoint of reactivity with isocyanate compounds used as curing agents described later, the (meth)acrylic resin may be a polyol having two or more hydroxyl groups in one molecule, and in particular may be a (meth)acrylic polyol.

[0413] The (meth)acrylic polyol may be a (meth)acrylic copolymer obtained by copolymerizing a hydrocarbon (meth)acrylate with a hydroxyl group-containing monomer, or a (meth)acrylic copolymer obtained by copolymerizing a hydrocarbon (meth)acrylate with a hydroxyl group-containing monomer and other monomer components (other monomer components). By copolymerizing the above monomers, a (meth)acrylic polyol containing multiple hydroxyl groups can be obtained.

[0414] The anchor coat layer 126 may contain a curing agent. From the viewpoint of excellent reactivity with (meth)acrylic resin, the curing agent may be an isocyanate compound having two or more NCO groups in its molecule.

[0415] The isocyanate compound may be a monomeric isocyanate. Examples of monomeric isocyanates include aromatic or aroliphatic isocyanates such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), xylene diisocyanate (XDI), and tetramethylxylylene diisocyanate (TMXDI); and aliphatic isocyanates such as hexamethylene diisocyanate (HDI), bisisocyanate methylcyclohexane (H6XDI), isophorone diisocyanate (IPDI), and dicyclohexylmethane diisocyanate (H12MDI).

[0416] The isocyanate compound may be a polymer or derivative of the above-mentioned monomer-based isocyanate. The isocyanate compound may be an isocyanate having a structure such as a trimer-type nurate, an adduct-type obtained by reacting with trimethylolpropane, or a biuret-type obtained by reacting with biuret. The isocyanate compound may be an isocyanate having an aromatic ring, from the viewpoint of excellent reactivity with (meth)acrylic resin.

[0417] When the (meth)acrylic resin is a (meth)acrylic polyol, the amount of isocyanate compound may be such that the number of OH groups in the acrylic polyol is equal to the number of NCO groups in the isocyanate compound.

[0418] The anchor coat layer 126 may contain a silane coupling agent to further improve adhesion with the vapor-deposited layer 127. Examples of silane coupling agents include epoxy-based silane coupling agents having epoxy groups such as 3-glycidoxypropyltrimethoxysilane, amino-based silane coupling agents having amino groups such as 3-aminopropyltrimethoxysilane, mercapto-based silane coupling agents having mercapto groups such as 3-mercaptopropyltrimethoxysilane, and isocyanate-based silane coupling agents having NCO groups such as 3-isocyanatetopropyltriethoxysilane. These silane coupling agents can be used individually or in combination of two or more types.

[0419] In addition, a urethane resin formed from acid group-containing polyurethane and polyamine can also be used as the material constituting the anchor coat layer 126. The urethane resin is obtained by bonding the acid group of the acid group-containing polyurethane with the amino group of the polyamine, which is used as a crosslinking agent. That is, the urethane resin can be said to be a reaction product of acid group-containing polyurethane and polyamine, or an acid group-containing polyurethane that has been crosslinked with polyamine. The bond between the acid group of the acid group-containing polyurethane and the amino group of the polyamine may be an ionic bond (for example, an ionic bond between a carboxyl group and a tertiary amino group) or a covalent bond (for example, an amide bond).

[0420] Furthermore, a silane coupling agent or a carbodiimide compound may be added to the above-mentioned urethane resin. By adding such a compound, a crosslinked structure is formed with the urethane resin, which can further improve gas barrier properties and adhesion between the main substrate layer 10 and the vapor-deposited layer 127. As the silane coupling agent, commonly used ones can be used, such as compounds in which an alkoxy group and an organic reactive group are bonded to a silicon atom.

[0421] The thickness of the anchor coat layer 126 is not particularly limited, as long as it is sufficient to improve the adhesion between the main substrate layer 10 and the substrate vapor deposition layer 127, but it is preferably 30 nm or more. In this case, compared to the case where the thickness of the substrate anchor coat layer 126 is less than 30 nm, it is possible to further improve the surface smoothness of the anchor coat layer 126, make the thickness of the vapor deposition layer 127 more uniform, and also further improve the oxygen barrier properties. Therefore, the oxygen barrier properties of the substrate layer 1 can be further improved. The thickness of the anchor coat layer 126 is more preferably 40 nm or more, and even more preferably 50 nm or more. By increasing the thickness of the anchor coat layer 126, the decrease in water vapor barrier properties when external forces such as stretching are applied can be further suppressed.

[0422] The thickness of the anchor coat layer 126 is preferably 2,000 nm (2 μm) or less. In this case, the flexibility of the substrate layer 1 is further improved compared to when the thickness of the anchor coat layer 126 exceeds 2,000 nm, and the oxygen gas barrier properties of the substrate layer 1 after abuse can be further improved. The thickness of the anchor coat layer 126 is more preferably 1,500 nm (1.5 μm) or less.

[0423] The anchor coat layer 126 can be formed, for example, by applying an anchor coat solution onto the resin layer using methods such as gravure coating, roll coating, or bar coating, and then drying it.

[0424] To improve the adhesion between the main substrate layer 10 and the vapor-deposited layer 127, instead of the anchor coat layer 126, surface treatments such as plasma treatment or corona treatment may be performed on the surface of the main substrate layer 10 on the side where the vapor-deposited layer 127 is formed. Alternatively, the anchor coat layer 126 may be provided on the surface of the main substrate layer 10 that has undergone surface treatment.

[0425] (deposited layer) The vapor-deposited layer 127 contains an inorganic oxide. The vapor-deposited layer 127 may be formed directly on the anchor coat layer 126, from the viewpoint of improving gas barrier properties against water vapor, oxygen, etc. The vapor-deposited layer 127 may also be transparent.

[0426] Examples of inorganic oxides that can be used include aluminum oxide, silicon oxide, tin oxide, magnesium oxide, and mixtures thereof. From the viewpoint of excellent bactericidal resistance, the inorganic oxide may be at least one selected from aluminum oxide and silicon oxide.

[0427] The thickness of the vapor-deposited layer 127 may be 5 nm or more, 10 nm or more, or 15 nm or more, from the viewpoint of ensuring uniform film thickness and excellent gas barrier properties. From the viewpoint of making it less likely for cracks to form in the vapor-deposited layer 127 even when external force is applied after film formation, it may be 300 nm or less, 150 nm or less, or 100 nm or less. From these viewpoints, the thickness of the vapor-deposited layer 127 for the substrate may be 5 to 300 nm, 10 to 150 nm, or 15 to 100 nm.

[0428] The vapor-deposited layer 127 can be formed by, for example, vacuum deposition, plasma-assisted deposition, ion beam-assisted deposition, sputtering, reactive deposition, etc. From the viewpoint of excellent productivity, the vapor-deposited layer 127 may be formed by vacuum deposition; from the viewpoint of excellent adhesion between the vapor-deposited layer 127 and the resin layer, and from the viewpoint of improving the density of the vapor-deposited layer 127, it may be formed by plasma-assisted deposition or ion beam-assisted deposition; and from the viewpoint of excellent transparency of the vapor-deposited film, it may be formed by reactive deposition by blowing in various gases such as oxygen.

[0429] Heating methods for vacuum deposition include electron beam heating, resistance heating, and induction heating. From the viewpoint of offering a wide range of selectivity for the evaporation material, electron beam heating may also be used as the heating method for vacuum deposition.

[0430] The vapor-deposited layer 127 may be a metal vapor-deposited layer. The metal vapor-deposited layer is provided on the substrate film, for example, from the viewpoint of improving gas barrier properties against water vapor and oxygen, and from the viewpoint of light shielding properties. The metal vapor-deposited layer is a vapor-deposited layer containing a metal. As the metal, aluminum is preferred from the viewpoint of gas barrier properties and light shielding properties. The metal vapor-deposited layer is preferably an aluminum vapor-deposited layer in which aluminum has been deposited.

[0431] The thickness of the metal deposition layer may be 5 to 300 nm. If the thickness of the metal deposition layer is 5 nm or more, a uniform and sufficiently thick film can be easily obtained, allowing the substrate barrier layer 15 to fully perform its function and making it easier to obtain better light shielding properties. Furthermore, if the thickness of the metal deposition layer is 300 nm or less, flexibility can be imparted to the metal deposition layer, making it less likely for cracks to occur in the metal deposition layer even if external factors such as bending or stretching are applied after film formation. From this viewpoint, the thickness of the metal deposition layer is preferably 6 nm or more, more preferably 150 nm or less, and even more preferably 100 nm or less.

[0432] The metal deposition layer can be formed by a conventional vacuum deposition method. Other thin-film formation methods such as sputtering, ion plating, and plasma vapor deposition (CVD) can also be used. However, considering productivity, vacuum deposition is currently the most superior method. For heating in vacuum deposition, it is preferable to use one of the following methods: electron beam heating, resistance heating, or induction heating. However, considering the wide range of selectivity for evaporation materials, electron beam heating is more preferable. Furthermore, to improve the adhesion between the metal deposition layer and the main substrate layer 10 and the density of the metal deposition layer, it is also possible to perform deposition using plasma-assisted or ion beam-assisted methods. In addition, to increase the transparency of the deposited film, reactive deposition, in which various gases such as oxygen are blown in during deposition, may be used.

[0433] (Gas barrier coating layer for substrates) The substrate layer 1, by having a gas barrier coating layer 128, can protect the vapor-deposited layer 127, further improving its gas barrier properties.

[0434] The gas barrier coating layer 128 may contain a silicon compound or its hydrolysate and a water-soluble polymer having a hydroxyl group.

[0435] Examples of silicon compounds include Si(OR 1 )4 and R 2 Si(OR 3) One or more types selected from 3. OR 1 and OR 3 Each of these is independently a hydrolyzable group, and R 2 R is an organic functional group. 2 Examples include vinyl groups, epoxy groups, methacryloxy groups, ureido groups, isocyanate groups, etc. Si(OR 1 )4 may be tetraethoxysilane (Si(OC2H5)4) from the viewpoint of being relatively stable in aqueous solvents after hydrolysis.

[0436] Examples of water-soluble polymers having hydroxyl groups include polyvinyl alcohol, polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, and sodium alginate. From the viewpoint of excellent gas barrier properties, polyvinyl alcohol (PVA) and ethylene-vinyl alcohol copolymer (EVOH) are preferred as water-soluble polymers having hydroxyl groups, and EVOH is more preferred from the viewpoint of heat resistance and gas barrier properties.

[0437] Examples of PVA include resins obtained by polymerizing vinyl esters such as vinyl acetate, vinyl formate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl pivalate, and vinyl versaticate individually, and then saponifying them.

[0438] A coating solution containing a polyvinyl alcohol-based resin and a liquid medium can be used to form the gas barrier coating layer 128. This coating solution can be obtained, for example, by dissolving a powder of a polyvinyl alcohol-based resin obtained by synthesis in a liquid medium. Examples of liquid media include water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide N-methylpyrrolidone, various glycols, polyhydric alcohols such as trimethylolpropane, and amines such as ethylenediamine and diethylenetriamine. These may be used individually or in combination of two or more. From the viewpoint of reducing environmental impact, water can be used as the liquid medium. In this case, the coating solution can be obtained by dissolving the powder of the polyvinyl alcohol-based resin in water at a high temperature (e.g., 80°C).

[0439] The content of polyvinyl alcohol-based resin (solids) in the coating solution can be 3 to 20% by mass from the viewpoint of maintaining good coatability. The coating solution may contain additives such as isocyanates and polyethyleneimines to improve adhesion. The coating solution may also contain additives such as preservatives, plasticizers (alcohol, etc.), and surfactants.

[0440] The coating solution can be applied to the vapor-deposited layer 127 by any suitable method. For example, the coating solution can be applied by a wet deposition method such as a gravure coater, dip coater, reverse coater, wire bar coater, or die coater. The application temperature and drying temperature of the coating solution are not particularly limited and can be, for example, 50°C or higher.

[0441] The gas barrier coating layer 128 may be formed on the vapor-deposited layer 127 by extrusion. In this case, multilayer extrusion using a T-die can be employed. Examples of adhesives that can be used during extrusion include two-component curing polyurethane adhesives, which consist of a main component such as a polyester polyol, polyether polyol, or acrylic polyol, and a difunctional or more aromatic or aliphatic isocyanate compound as a curing agent. The adhesive layer may be pre-formed on the vapor-deposited layer 127 by coating the above adhesive components onto the vapor-deposited layer 127 and then drying it. When using a urethane resin adhesive, after coating, aging at 40°C for 4 days or more allows the reaction between the hydroxyl groups of the main component and the isocyanate groups of the curing agent to proceed, enabling strong adhesion. The thickness of the adhesive layer can be 0.05 to 2 μm, or 0.1 to 1 μm, from the viewpoint of adhesion, conformability, and processability.

[0442] The gas barrier coating layer 128 may further contain additives such as isocyanate compounds, silane coupling agents, dispersants, stabilizers, viscosity modifiers, and colorants as described above.

[0443] The thickness of the gas barrier coating layer 128 may be 0.1 μm or more, or 0.3 μm or more, or 5 μm or less, or 1 μm or less. The thickness of the gas barrier coating layer 128 may be 0.1 to 5 μm or 0.3 to 1 μm.

[0444] The gas barrier coating layer 128 can be formed, for example, by dissolving a water-soluble polymer in water or a water / alcohol mixed solvent, then mixing in a silicon compound or its hydrolysate, and applying this mixed solution onto the vapor-deposited layer 127 by methods such as gravure coating, roll coating, or bar coating, and then drying it.

[0445] When the water-soluble polymer is polyvinyl alcohol, the polyvinyl alcohol content in the mixed solution may be 20% by mass or more or 25% by mass or more, based on the total solid content of the mixed solution, from the viewpoint of easily forming a gas barrier coating layer 128 for the substrate, or it may be 50% by mass or less or 40% by mass or less, from the viewpoint of excellent gas barrier properties. The polyvinyl alcohol content in the mixed solution may be 20-50% by mass or 25-40% by mass, based on the total solid content of the mixed solution.

[0446] The base layer 1 does not necessarily have an anchor coat layer 126, nor does it necessarily have a gas barrier coating layer 128, nor does it necessarily have both an anchor coat layer 126 and a gas barrier coating layer 128. Furthermore, the base layer 1 may have a gas barrier coating layer 128 between the main base layer 10 and the vapor-deposited layer 127.

[0447] Here, if the main base layer 10 is a stretched polypropylene (OPP) film, an organic compound such as propyl myristate is usually added as a nucleation material for the crystals necessary to form the OPP film. If such an organic compound bleeds to the surface of the printed material 110 opposite to the sealant layer 2, when the printed material 110 is manufactured and wound up, it may adhere to the sealant layer 2, migrate, and become mixed into the contents. In addition, irradiation with active energy rays may alter the above organic compound and other components, and in this case, a compound that is more prone to bleeding may be generated. The migration of bleed material to the sealant layer 2 is undesirable from a food hygiene standpoint, so it is necessary to suppress it. In this regard, by providing the printed material 110 with a protective layer 6, the protective layer 6 is interposed between the base layer 1 and the sealant layer 2 when the printed material 110 is wound up, so the migration of bleed material to the adjacent sealant layer 2 can be suppressed during winding. Furthermore, by including an anchor coat layer 126, a vapor deposition layer 127, a gas barrier coating layer 128, etc., the migration of bleed material within the printed material 110 to the sealant layer 2 can be suppressed.

[0448] It is preferable to apply plasma treatment to the surface of the substrate layer 1. This changes the wettability of the surface, and this change in wettability causes the hydroxyl groups (OH groups) of the compounds present on the surface to rise from the surface, thereby improving the adhesion between the substrate layer 1 and the adjacent layer. Furthermore, by laminating the gas barrier coating layer 128 on the surface of the vapor-deposited layer 127 in the substrate layer 1 as described above, the adhesion between the substrate layer 1 and the ink layer 4 can be improved.

[0449] [Modified layer] The modified layer 3 may be formed from a polyurethane resin obtained by reacting a bifunctional or more isocyanate compound with, for example, a polyester polyol, polyether polyol, acrylic polyol, or carbonate polyol.

[0450] From the viewpoint of improving adhesion, the modified layer 3 may contain, in addition to the urethane resin, a carbodiimide compound, an oxazoline compound, an epoxy compound, a phosphorus compound, and a silane coupling agent.

[0451] The thickness of the modified layer 3 is not particularly limited and may be, for example, 0.1 μm or more. Sufficient adhesive strength can be obtained by making the thickness of the modified layer 3 1 μm or more. The thickness of the modified layer 3 may be 2 μm or more. The thickness of the modified layer 3 may be 50 μm or less, 5 μm or less, or 3 μm or less.

[0452] [Sealant layer] The sealant layer 2 includes a polypropylene film. The polypropylene film contains polypropylene. The polypropylene film may be, for example, a film formed by stretching polypropylene after it has been made into a sheet and then oriented uniaxially or biaxially.

[0453] The polypropylene content may be 90% by mass or more, 95% by mass or more, or 99% by mass or more, based on the total mass of the sealant layer 2. The polypropylene content may also be substantially 100% by mass (in an embodiment where the sealant layer 2 is made of polypropylene), based on the total mass of the sealant layer 2.

[0454] The thickness of sealant layer 2 may be 10 μm or more, or 20 μm or more, and may be 200 μm or less, or 100 μm or less. The thickness of sealant layer 2 may be 10 to 200 μm or 20 to 100 μm.

[0455] <Protective layer> The protective layer 6 includes a polypropylene film. The polypropylene film contains polypropylene. The polypropylene film may be, for example, a film formed by stretching polypropylene after it has been made into a sheet and then oriented uniaxially or biaxially.

[0456] The protective layer 6 can be provided by bonding it to other adjacent films via an adhesive. For example, a two-component curing urethane adhesive can be used as the adhesive.

[0457] Polypropylene may be crystalline polypropylene. From the viewpoint of improving heat resistance, polypropylene may also be homopolypropylene, which is a homopolymer of propylene. Polypropylene may contain, for example, a random copolymer of propylene and α-olefin.

[0458] The polypropylene content may be 90% by mass or more, 95% by mass or more, or 99% by mass or more, based on the total mass of the protective layer 6. The polypropylene content may also be substantially 100% by mass (in an embodiment where the protective layer 6 is made of polypropylene), based on the total mass of the protective layer 6.

[0459] The protective layer 6 may contain organic additives such as antiblocking agents (AB agents), antioxidants, stabilizers, lubricants, and antistatic agents, or it may contain inorganic additives such as silica, zeolite, hydrotalcite, silica particles, and thyroid.

[0460] The antiblocking agent (AB) may be either organic or inorganic particles. Examples of organic particles include polymethyl methacrylate particles, polystyrene particles, and polyamide particles. Examples of inorganic particles include silica particles, zeolite, talc, kaolinite, and feldspar. These antiblocking agents may be used individually or in combination of two or more.

[0461] Considering antiblocking performance, it is preferable to use AB agents with an average particle size of 0.1 to 5 μm. The average particle size is the weight-average diameter measured by the coal tar method.

[0462] The thickness (total thickness) of the protective layer 6 is not particularly limited, but may be, for example, 3 μm to 200 μm, 6 μm to 50 μm, or 10 μm to 30 μm.

[0463] The polypropylene used in the protective layer 6 may be a resin polymerized from fossil fuels, recycled polypropylene, or polypropylene obtained by polymerizing biomass-derived raw materials such as plants. When using these polypropylenes, they may be used individually, or a mixture of polypropylene polymerized from fossil fuels and recycled polypropylene or polypropylene obtained by polymerizing biomass-derived raw materials such as plants may be used.

[0464] The heat resistance of the printed material 110 also requires heat resistance related to the sealing bar (i.e., heat resistance of the base material layer 1 containing polypropylene). To enhance this heat resistance, the protective layer 6 is preferably a heat-resistant layer, and the heat-resistant layer preferably contains an active energy ray (e.g., electron beam) curable resin. By containing an active energy ray curable resin in the heat-resistant layer, after applying ink (printing) to the base material layer 1 and applying the heat-resistant layer forming material, the formation of the ink layer 4 and the heat-resistant layer can be performed simultaneously with a single irradiation of active energy rays.

[0465] When the printed material 110 is used as packaging material with a spout, the spout portion and the entire spout of the cap may be made of the same resin as the main base material layer 10, from the viewpoint of improving recyclability.

[0466] <Application> The printed material 110 can be used for the same purposes as the printed material 108 of the eighth embodiment.

[0467] [Embodiment No. 11] Figure 12 is a schematic cross-sectional view showing the layer structure of a printed material according to the 11th embodiment of the present invention. The printed material 111 shown in Figure 12 is a laminate formed by reverse offset printing. The printed material 111 comprises, from the top (surface side), a protective layer 6, a substrate layer 1, an ink layer 4, a modification layer 3, a barrier layer 5, an adhesive layer 7, and a sealant layer 2, in this order.

[0468] The printed material 111 has the same configuration as printed material 110, except that the base layer 1 comprises only the main base layer 10, and further comprises a barrier layer 5 and an adhesive layer 7. Furthermore, like printed material 110, printed material 111 has a configuration particularly favorable for achieving monomaterialization. The ink layer 4, modified layer 3, and sealant layer 2 of printed material 111 have the same configuration as those described in the 10th embodiment, and the printing method and the method of irradiation with active energy rays can also be the same as those in the 10th embodiment.

[0469] <Base material layer> The base layer 1 comprises a main base layer 10 similar to that of the printed material 110. Since the configuration of the main base layer 10 is the same as in the tenth embodiment, a detailed explanation is omitted. The base layer 1 may also have an anchor coat layer, a vapor deposition layer, a gas barrier coating layer, etc., similar to those in the tenth embodiment.

[0470] <Barrier layer> The barrier layer 5 has, from the modified layer 3 side, a gas barrier layer 52 and a barrier substrate layer 51 in that order. The barrier substrate layer 51 has the same configuration as the main substrate layer 10 of the substrate layer 1 of the printed material 110. Specifically, the barrier substrate layer 51 has a first skin layer 514, a core layer 515, and a second skin layer 516, similar to the first skin layer 121, core layer 122, and second skin layer 123 of the main substrate layer 10, respectively. The gas barrier layer 52 has an anchor coat layer 523, a vapor deposition layer 524, and a gas barrier coating layer 525, similar to the anchor coat layer 126, vapor deposition layer 127, and gas barrier coating layer 128 of the substrate layer 1 of the printed material 110, respectively. In barrier layer 5, the first skin layer 514, core layer 515, second skin layer 516, anchor coat layer 523, vapor deposition layer 524, and gas barrier coating layer 525 are laminated in this order. For this reason, a detailed explanation of barrier layer 5 will be omitted.

[0471] <Adhesive layer> The adhesive layer 7 can be the same as the adhesive layer 7 in the ninth embodiment.

[0472] In printed material 111, the content of the same type of resin (polypropylene) may be 90% by mass or more. In this case, printed material 111 can be constructed as a highly recyclable monomaterial. Alternatively, even in the case of olefin resins, from the viewpoint of recycling, a monoolefin structure may be adopted in which 90% by mass or more of resins that are not identical but belong to the olefin family, such as polyethylene in the sealant layer 2 and polypropylene in the base layer 1, is included.

[0473] As described above, the printed material 111 of this embodiment provides the same effects as the printed material 110 of the tenth embodiment. In addition, it also provides barrier properties due to the barrier layer 5.

[0474] <Application> Printed material 111 can be used for the same purposes as printed material 110 in the tenth embodiment.

[0475] Based on the above findings, the inventors have created a printing medium that improves not only adhesion to the ink layer but also strength and flexibility by moderately reducing the irradiation dose. A twelfth embodiment of the printing medium of the present invention will now be described. The printing medium of the present invention also includes materials obtained by irradiation with active energy rays. In this case, as described above, the mechanism by which irradiation with active energy rays improves adhesion to the ink, strength, and flexibility is not fully understood. Therefore, it may be considered impractical to completely specify the structure of the printing medium of the present invention as a physical object.

[0476] [Twelfth Embodiment] The twelfth embodiment is a printed material according to the second embodiment, in which a resin substrate layer containing recycled material is used as the substrate layer. That is, the printed material 112 (not shown) of the twelfth embodiment, like in Figure 3, comprises a substrate layer 1, an ink layer 4, a modified layer 3, and a sealant layer 2 in this order from the top (surface side), and the substrate layer 1 is a resin substrate layer containing recycled material. The printed material 112 has the same configuration as the printed material 102 except that the substrate layer 1 is a resin substrate layer containing recycled material. The ink layer 4, modified layer 3, and sealant layer 2 of the printed material 112 have the same configuration as those described in the second embodiment, and the printing method and the method of irradiation with active energy rays can also be the same as in the second embodiment.

[0477] Resin substrate layers containing recycled materials may contain impurities compared to resin substrate layers made from petroleum-derived resins, which can result in the presence of foreign matter such as fisheyes. Therefore, the surface smoothness of the resin substrate layer, which is the printing surface, may not be high or consistent, and the printability may be inferior to that of resin substrate layers made from petroleum-derived resins. However, in this embodiment, the printed material 112 can be printed with high precision even on such resin substrate layers containing recycled materials by performing offset printing with an active energy ray-curable ink containing an active energy ray-curable resin.

[0478] <Resin substrate layer containing recycled materials> As the resin substrate layer containing recycled materials, material-recycled polyethylene terephthalate (PET) film, chemically recycled polyethylene terephthalate (PET) film, material-recycled polyethylene (PE) film, chemically recycled polyethylene (PE) film, material-recycled polypropylene (PP) film, chemically recycled polypropylene (PP) film, material-recycled nylon (NY) film, chemically recycled nylon (NY) film, etc., can be used. These resin substrate layers containing recycled materials may be single layers or multiple layers. For example, the resin substrate layer containing recycled materials may use a three-layer co-extruded film consisting of a resin film made from petroleum-derived resin, a resin film made from recycled resin, and a resin film made from petroleum-derived resin. It is also possible to use a laminated film of a resin film made from recycled resin and a resin film made from biomass-derived resin. Furthermore, the resin substrate layer containing recycled materials may also use a resin film made from a mixture of recycled resin pellets and petroleum-derived resin pellets. For example, a resin substrate layer containing recycled materials with a recycled resin ratio of 80% can be made by mixing recycled resin pellets and petroleum-derived resin pellets in an 8:2 ratio and forming a film. Furthermore, the mixing ratio of recycled resin pellets and petroleum-derived resin pellets can be any ratio from the perspective of the quality, physical properties, and cost required for recycled materials. In addition, the resin film made from the mixture of recycled resin pellets and petroleum-derived resin pellets may be a single layer or multiple layers. If the resin substrate layer containing recycled material is multiple layers, it may be a laminate of multiple resin films made from the mixture of recycled resin pellets and petroleum-derived resin pellets, or it may be a laminate of a resin film made from recycled resin pellets and a resin film made from petroleum-derived resin pellets or a resin film made from biomass-derived resin pellets.

[0479] <Application> The printed material 112 can be used for the same purposes as the printed material 102 of the second embodiment.

[0480] [13th Embodiment] The 13th embodiment is a printing medium having a base layer suitable for use as base layer 1 in printed materials according to the first to 12th embodiments. Therefore, when a printed material is constructed using the printing medium of this embodiment as the base layer, the same configuration as the base layer 1 other than the base layer 1 in the first to 12th embodiments can be adopted. Furthermore, the printing medium may appropriately adopt the configuration of the base layer 1 in the first to 12th embodiments, except that it has the following configuration. Also, the base layer of the printing medium may be one layer or multiple layers, as in the first embodiment, and if it is multiple layers, it may include an easy-adhesion layer, a barrier layer, etc., may include multiple barrier layers, and may be surface-treated.

[0481] When the printing medium of this embodiment is bonded to other layers, either the modified layer 3 of the first embodiment or the adhesive layer 7 of the third embodiment may be used as the adhesive layer. However, using the modified layer 3 further enhances the adhesion between the substrate layer 1 and the ink layer 4.

[0482] The printing medium of this embodiment is a printing medium suitable for active energy ray offset printing, and comprises a substrate layer having affinity for at least an active energy ray curable resin, thereby improving adhesion with ink.

[0483] By providing a substrate layer that has affinity for at least an active energy ray-curable resin, the printing medium can maintain a high level of adhesion between the ink and the substrate layer even after the ink has hardened due to irradiation with active energy rays. It is presumed that irradiation with active energy rays suppresses crosslinking (covalent bonding) in the substrate layer, and that weaker interactions than crosslinking, such as electrostatic interactions (ionic bonds, hydrogen bonds, dipole interactions, van der Waals forces, etc.), act between the substrate layer and other layers such as the ink layer, thereby increasing the adhesion between the substrate layer and the ink layer. Furthermore, it is presumed that the strength of the substrate layer is also increased by suppressing unnecessary crosslinking within the substrate layer.

[0484] In printing media, an ink layer is formed on top of the surface by offset printing, and the active energy rays are irradiated along with the ink layer. During this process, not only the ink layer but also the printing media itself is irradiated with active energy rays. Therefore, it is crucial to appropriately set the acceleration voltage and irradiation dose of the active energy rays.

[0485] <Accelerating voltage of activated energy rays> The acceleration voltage of the active energy ray can be appropriately set in relation to the irradiation dose so as to suppress unwanted crosslinking within the substrate layer. Particularly considering the curing reaction of the ink layer, the acceleration voltage should be as low as possible, for example, 120kV or less is preferred. By setting the acceleration voltage below the above upper limit, in combination with setting the irradiation dose within the above range, unwanted crosslinking between resin molecules within the substrate layer can be suppressed. The lower limit of the acceleration voltage may be, for example, 10kV or more, 30kV or more, or 50kV or more.

[0486] <Irradiation dose of activated energy rays> To improve the adhesion between the substrate layer and the ink layer, the irradiation dose of the active energy ray is preferably 10 to 100 kGy, more preferably 20 to 60 kGy, and even more preferably 25 to 50 kGy in the case of an electron beam. By setting the irradiation dose within the above range, unwanted crosslinking between resin molecules in the substrate layer can be suppressed, thereby improving adhesion with the ink layer. Furthermore, the strength of the printing medium can be increased. From this viewpoint, a printed material using the printing medium of this embodiment comprises an ink layer containing an active energy ray curable resin and a substrate layer having affinity for the active energy ray curable resin, and is preferably irradiated with an electron beam of preferably 10 to 100 kGy, more preferably 20 to 60 kGy, and even more preferably 25 to 50 kGy.

[0487] <Crystallization of Printed Media> When the substrate layer is a crystalline material such as polyethylene, irradiation with active energy rays can change the crystallinity of the resin in the substrate layer compared to before irradiation. Therefore, by using the crystallinity of the substrate layer after irradiation as an indicator, it is possible to understand the effects on adhesion to the ink layer, strength of the substrate layer, etc. The crystallinity of the substrate layer can be measured by microangle incidence X-ray diffraction. Microangle incidence X-ray diffraction can be performed, for example, using an X-ray diffractometer (ATX-G, manufactured by Rigaku Corporation) under the following conditions. ·X-ray source: CuKα Voltage and current values: 50kV, 300mA • Filter: Kβ removal (Ni) filter • Scanning method: Parallel beam • Scanning axis: 2θ method, a) Fixed angle = 0.10°, b) Fixed angle = 0.12° • Scanning speed: 4° / min • Sampling rate: 0.020° / min • Measurement range: 10° < 2θ < 30° or 35° • Detector: Scintillation counter detector (i.e., 0-dimensional detector) • Sample stage control mode: Fixed • Divergence (DS) slit: 0.1 mm • Vertical limiting slit: 10mm • Sample setup conditions: When the incidence angle is very small, such as a fixed angle of about 0.1°, the horizontality and smoothness of the measurement sample surface become important. Therefore, a glass slide (length: 2.6cm x width: 7.5cm x thickness: 1mm) is attached to the sample stage, and the PE film sample is placed on top of it. The parts of the glass slide that protrude from the top and bottom are pulled and attached with tape (fixing tape) to ensure the horizontality and smoothness of the measurement surface. Then, the sample stage is set on the sample stage so that the long axis of the slide coincides with the X-ray incidence direction (see Figure 14).

[0488] The irradiation dose of the active energy ray can be set to preferably 10 to 100 kGy, more preferably 20 to 60 kGy, and even more preferably 25 to 50 kGy, and is suitable when the substrate layer is mainly composed of polyethylene (PE). In this case, the substrate layer, which is a crystalline material irradiated with the active energy ray, is given by the following equation (1) in the X-ray diffraction pattern measured by micro-angle incident X-ray diffraction measurement using a 0-dimensional detector with the 2θ method using CuKα rays, where the intensity of the amorphous peak is I0, the intensity of the first peak (110) plane is I1, and the intensity of the second peak (200) plane is I2: R = (I1+I2) / I0 ···(1) The strength ratio R, expressed as , is designed to be between 2 and 20. When the PE of the base layer is high-density polyethylene (HDPE), the strength ratio R is preferably between 14 and 20. When the PE of the base layer is low-density polyethylene (LDPE), the strength ratio R is preferably between 2 and 3. When the PE of the base layer is linear low-density polyethylene (LLDPE), the strength ratio R is preferably between 6 and 7. Of these, the base layer is more preferably HDPE or LLDPE.

[0489] Furthermore, detectors used for minute-angle incident X-ray diffraction measurements using the 2θ method with CuKα rays are limited to zero-dimensional detectors. Zero-dimensional detectors include scintillation counter detectors, which have long been installed in X-ray diffraction systems, and in recent years, semiconductor detectors have also become available that allow selection of zero-dimensional / one-dimensional / two-dimensional measurement modes. The differences between zero-dimensional and multi-dimensional (one-dimensional, two-dimensional) detectors are as follows: In a zero-dimensional detector, there is no positional information on the detection surface, so the angle of the light-receiving arm on which the detector is mounted becomes the "diffraction angle" on the profile, and detection is performed point by point. In contrast, a one-dimensional detector has many elongated semiconductor detection elements arranged, and there is positional information in the 2θ direction of the detection surface, and the intensity of the X-rays counted by each element is integrated to output with high sensitivity. In a two-dimensional detector, many square semiconductor detection elements are arranged, and there is positional information on the detection surface in the 2θ direction and the χ direction (β direction on the data) perpendicular to it, so it is possible to output with even higher sensitivity, and the diffracted X-rays can be captured as a two-dimensional diffraction pattern.

[0490] However, because the detection principles differ between zero-dimensional and multi-dimensional (one-dimensional, two-dimensional) detectors, there is a slight difference in the intensity ratio between the detected amorphous halo peak and the crystalline diffraction peak. Therefore, in this invention, we have limited ourselves to zero-dimensional detectors (scintillation counter detectors and zero-dimensional semiconductor detectors) that were actually used in the measurements.

[0491] By setting the intensity ratio R within the above range, the adhesion between the substrate layer and other layers such as the ink layer can be improved. Furthermore, the strength, such as puncture resistance, and flexibility can be increased. Therefore, in a printing medium, the adhesion between the substrate layer and other layers such as the ink layer can be improved because the substrate layer is a crystalline material irradiated with active energy rays having a specific X-ray diffraction pattern. Furthermore, the strength of the substrate layer, such as puncture resistance, and flexibility can be increased.

[0492] Even when the substrate layer is made of a crystalline material such as polyethylene, at low absorbed doses of 100 kGy or less, as described above, the gel fraction does not change compared to before irradiation due to irradiation with active energy rays. Thus, it is presumed that while the crystallinity of the substrate layer changes with low absorbed dose irradiation, the gel fraction does not change, which can improve adhesion, strength, flexibility, etc.

[0493] When applying the printing medium of this embodiment to printed materials, it is preferable that the content of the same type of resin (e.g., polyethylene) is 90% by mass or more. In this case, the printed material can be constructed as a highly recyclable monomaterial. Alternatively, even in the case of olefin resins, from the viewpoint of recycling, a monoolefin structure may be adopted in which, for example, polyethylene is used in the sealant layer 2 and polypropylene is used in the base layer 1, containing 90% by mass or more of resins that are not identical but belong to the olefin family.

[0494] As described above, the printing medium of this embodiment has improved adhesion, strength, etc., and can therefore be suitably used as the base material layer of the first to twelfth embodiments described above.

[0495] <Application> The printing medium of this embodiment is suitable for the printed materials of the first to twelfth embodiments, and can also be used for the same purposes as the printed material 101 of the first embodiment and the printed material 102 of the second embodiment.

[0496] [14th Embodiment] The 14th embodiment is a package formed from printed materials according to the 1st to 12th embodiments. Figure 13 is a schematic diagram showing an example of a packaged product equipped with the package of the 13th embodiment of the present invention. The packaged product 200 shown in Figure 13 includes a packaging body 210 and contents contained therein (packaged goods, not shown).

[0497] The packaging 210 may be a standing pouch, for example, as shown in Figure 13. The packaging 210 can be formed using any of the printed materials 101 to 112 according to the first to twelfth embodiments described above. In this case, the printed materials 101 to 112 according to the first to twelfth embodiments can use the printing medium according to the thirteenth embodiment as the base material layer. That is, the packaging 210 can be formed using the printing medium according to the thirteenth embodiment. According to the packaging 210 of this embodiment, by being formed using the above-mentioned printed material or printing medium, the adhesion between the base material layer and the active energy ray curable resin is enhanced, and peeling and detachment of the active energy ray curable resin are suppressed.

[0498] Specifically, the packaging 210 includes a pair of main films and a bottom film, which are either printed materials as described in the first to twelfth embodiments, or cut from them. When the pair of main films and bottom films have a sealant layer (second to fifth embodiments, seventh to twelfth embodiments), their sealant layers are overlapped so that they face each other, and their periphery is heat-sealed to each other, except for one end and the area near it. The bottom film is folded in half so that it forms a mountain fold when viewed from the sealant layer side (so that the sealant layer is on the outside), and at the position of the one end, it is sandwiched between the pair of main films so that the mountain fold faces the other end of the main film (the side opposite to the one end). The bottom film is heat-sealed to the pair of main films in all parts except its central portion. The outer surfaces of the bottom film are bonded together at both sides of the bottom of the packaging 210. The packaging 210 is provided with a notch as an easy-open structure in the portion where the main films are heat-sealed to each other. The easy-open structure may be provided so that the upper corner of the packaged product 200 can be used as an opening after it has been opened. In addition, the packaged body 210 may have an opening member or a lid attached.

[0499] If the pair of main film and bottom film in the packaging 210 do not have a sealant layer, the packaging 210 can be formed by using an adhesive instead of bonding with a sealant layer, and otherwise in the same manner as when a sealant layer is present.

[0500] Examples of packaging bodies 210 include retort packaging bodies, boiling packaging bodies, microwave packaging bodies, and can label packaging bodies. The packaging bodies of the present invention are not limited to the above-mentioned standing pouches, but can be formed in various other forms such as flat pouches and gusseted pouches with spouts. Furthermore, the shape of the packaging body is not limited to four-sided pouches, but may also be two-sided pouches, three-sided pouches, or gusseted pouches.

[0501] The packaged items may be liquids, solids, or mixtures thereof, and examples include food products and pharmaceuticals. Specifically, examples include confectionery such as cookies and rice crackers, food products such as pizza, noodles, broth, and coffee, health foods such as supplements, pharmaceuticals, animal products such as fish feed, pet food, and pet treats, vegetable seeds, and frozen foods.

[0502] The configurations of the first to fourteenth embodiments described above can, of course, be adopted from each other as appropriate. Furthermore, the present invention is not limited to the above embodiments. [Examples]

[0503] Next, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0504] [Test Example 1] (Production of printed materials) [Example 1] A PET film (manufactured by Unitika Ltd., product name: Emblet PTM, thickness 12 μm) was used as the base layer. Using a COMEXI CI-8 offset printing press, a predetermined print was performed on the easily adhesive layer surface using a water-based offset printing method with dampening solution and an ink containing an electron beam-curable resin. The ink used was a thermoplastic resin containing a copolymer of ethylene acrylic acid and ethylene methacrylic acid. The ink colors used were black (K), cyan (C), magenta (M), yellow (Y), and white (W), as shown in Table 1. In Table 1, "KWW," etc., indicate the order in which the colors were applied from left to right, starting from the base layer. As shown in Table 1, multiple samples with different ink colors and ink coverage rates were prepared. Each ink coverage rate was adjusted by printing each color in solid color on an offset printing press. The ink coverage rates ranged from 100% to 500%.

[0505] After printing, the print was irradiated with an electron beam (EB) at a dose of 30 kGy from the ink layer side under a nitrogen atmosphere using an electron beam irradiation device (EC series, manufactured by ENERGY SCIENCES, INC.). Subsequently, the ink modifier was applied to the cured ink layer using a bar coater device, and the diluted solvent was dried and vaporized in an electric dryer (FS-45W, manufactured by Tokyo Glass Equipment Co., Ltd.) at 100°C for 1 minute to form a modified layer and obtain the print of Example 1. The ink modifier was prepared by blending an aliphatic polyester polyol (manufactured by Mitsui Chemicals, Inc., trade name: Takelac A626, sometimes referred to as "(C)") as the main ingredient, polyisocyanate (manufactured by Mitsui Chemicals, Inc., trade name: Takenate A50, sometimes referred to as "(D)") as the curing agent, and ethyl acetate as the solvent, to prepare an ink modifier with a solid content concentration of 36.5% by mass. The mass-based mixing ratio (by mass) of each component was set to (C):(D)=8:1. The application amount of the modified layer was 3.0g / m². 2 I set it to that.

[0506] [Comparative Example 1] A printed material of Comparative Example 1 was obtained in the same manner as in Example 1, except that an ink modifier was not applied to the ink layer.

[0507] [Evaluation of adhesion] The prints from Example 1 and Comparative Example 1 were grasped with both hands at a 10 cm distance apart and twisted 10 times. The presence or absence of ink detachment from the substrate layer was used as an indicator of adhesion. Those without ink detachment were rated A (good), and those with detachment were rated B (poor).

[0508] [Table 1]

[0509] In the printed material of Example 1, which has a modified layer, no ink peeling was observed even when the ink layer was subjected to impact, not only when a single color of ink was applied, but also when multiple colors of ink were applied. This is presumed to be because the ink modifier penetrated between and into the ink particles in the relatively hard ink layer, thereby improving the adhesion between the ink particles and the adhesion between the ink particles and the substrate layer. Furthermore, it is presumed that cracking of the ink layer was suppressed because the ink layer was protected by a modified layer containing a relatively flexible urethane resin.

[0510] In contrast, in Comparative Example 1, which lacked a modified layer, when the ink layer was subjected to impact, no ink peeling occurred when a single color of ink was applied, but ink peeling was observed when multiple layers of ink were applied. This is presumed to be because the ink layer hardened by electron beam irradiation becomes relatively hard, and as the thickness of the hard ink layer increases, it becomes more difficult for it to follow the deformation of the substrate layer.

[0511] Thus, it was shown that printed materials with a modified layer exhibit improved adhesion and flexibility compared to printed materials without a modified layer.

[0512] [Test Example 2] Evaluation of adhesion between the substrate layer and the ink layer depending on the type of substrate layer (1) PET film and NY film were used as the base layer. Specifically, as the PET film, in Example 2, a PET film having an acrylic resin layer as an easy-adhesion layer (manufactured by Unitika Ltd., product name: Emblet PTM, thickness 12 μm) was used, similar to Test Example 1. In Comparative Example 2, a PET film having a corona-treated surface (manufactured by Futamura Co., Ltd., product name: FE2001, 12 μm, with the other surface of the PET film being untreated) was used, with one surface of the PET film being corona-treated. As the NY film, in Example 3, an NY film having an acrylic resin layer as an easy-adhesion layer (manufactured by Kojin Film & Chemicals Co., Ltd., product name: Bonil Q, thickness 15 μm) was used, with one surface of the NY film having a corona-treated surface (manufactured by Kojin Film & Chemicals Co., Ltd., product name: Bonil RX, thickness 15 μm). Using an offset printing press (COMEXI CI-8), the predetermined printing was performed on the surface of each easy-adhesion layer or the corona-treated surface using an ink containing electron beam (EB) curable resin with dampening solution. The ink used was a thermoplastic resin containing a copolymer of ethylene acrylic acid and ethylene methacrylic acid. As shown in Table 2, magenta (M) was used as the ink color. As shown in Table 2, laminates (printed materials before EB irradiation) of Examples 2 and 3 and Comparative Examples 2 and 3 were prepared with the ink coverage rate set to 100%. The ink coverage rate was adjusted by overlapping each color with solid plates on the offset printing press.

[0513] After printing, the printed materials for Examples 2 and 3, and Comparative Examples 2 and 3 (printed materials after EB irradiation) were prepared by irradiating the ink layer side with an electron beam (EB) at a dose of 45 kGy under a nitrogen atmosphere using an electron beam irradiation device (EC series, manufactured by ENERGY SCIENCES, INC.). To evaluate the adhesion of the printed materials for Examples 2 and 3, and Comparative Examples 2 and 3, a cellophane tape peel test was performed according to the method described below.

[0514] [Cellophane tape peel test] Using 15mm wide cellophane tape (manufactured by Nichiban Co., Ltd., product name: Cellotape (registered trademark) CT405AP-15), the adhesive side of the cellophane tape was applied to the surface of each ink layer in the laminates (printed material before EB irradiation) and printed material (printed material after EB irradiation) of Examples 2 and 3, and Comparative Examples 2 and 3, so that the length of the cellophane tape at the adhesion surface with the ink layer was 15mm or more (i.e., the area of ​​the adhesive surface was 225mm). 2 The tape was applied so that it was at least 15 x 15 mm in size. At this time, an unadhesive portion (pull allowance) was left at one end of the cellophane tape in the longitudinal direction for pulling the tape. Then, the unadhesive portion was grasped with fingers and peeled off quickly, and the area of ​​the adhesive surface between the ink layer and the cellophane tape after peeling was 15 mm wide x 15 mm long (i.e., an area of ​​225 mm²). 2 The ink retention rate in a region of 15 × 15 was measured using a metal ruler. The results are shown in Table 2.

[0515] [Table 2]

[0516] As shown in Table 2, the easy-adhesion layer in the substrate layers of Examples 2 and 3 had an ink retention rate of 0% before EB irradiation (all the ink had peeled off), whereas after EB irradiation, the ink retention rate was 100%. Therefore, it was shown that EB irradiation improves the adhesion between the substrate layer and the ink layer. From this, it is considered that the substrate layers of Examples 2 and 3 (more specifically, the substrate layers including the easy-adhesion layer) have affinity for the electron beam (EB) curable resin contained in the ink layer, and therefore, EB irradiation can improve the adhesion with the ink layer. In contrast, the corona-treated surfaces of the substrate layers in Comparative Examples 2 and 3 showed an ink retention rate of 0% before EB irradiation and a retention rate of 5% after EB irradiation. Therefore, it was shown that EB irradiation does not improve the adhesion between the substrate layer and the ink layer. From this, it is considered that the substrate layers of Comparative Examples 2 and 3 (more specifically, the substrate layers including the corona-treated surfaces) do not have affinity for the electron beam (EB) curable resin contained in the ink layer, and therefore, EB irradiation does not improve the adhesion with the ink layer. In Examples 2 and 3, the adhesion between the substrate layer and the ink layer can be further improved by laminating a modified layer on top of the ink layer. Similarly, in Comparative Examples 2 and 3, the adhesion between the substrate layer and the ink layer can also be improved by laminating a modified layer on top of the ink layer.

[0517] [Test Example 3] Evaluation of adhesion between the substrate layer and the ink layer depending on the type of substrate layer (2) PET film was used as the base layer. Specifically, in Examples 4-6, a PET film with an easy-adhesion layer (manufactured by Unitika Ltd., product name: Emblet PTM, thickness 12 μm), similar to that used in Test Example 2, was used. In Comparative Examples 4-8 and Example 7, a PET film with one surface being corona-treated (manufactured by Futamura Co., Ltd., product name: FE2001, 12 μm, the other surface of the PET film being untreated), similar to that used in Test Example 2, was used. Using an offset printing press (COMEXI, CI-8), the predetermined printing was performed on the surface of each easy-adhesion layer, the corona-treated surface, or the untreated surface using an ink containing electron beam (EB) curable resin with dampening solution. The ink used was a thermoplastic resin containing a copolymer of ethylene acrylic acid and ethylene methacrylic acid. As shown in Table 3, magenta (M) was used as the ink color. As shown in Table 3, the ink coverage rate was set to 100% to prepare the laminates (printed materials before EB irradiation) of Examples 4-7 and Comparative Examples 4-8. The ink coverage was adjusted by printing each color in layers using a solid plate on an offset printing press.

[0518] After printing, the printed materials for Examples 4-7 and Comparative Examples 4-8 were prepared by irradiating the ink layer side with an electron beam (EB) from the ink layer side under a nitrogen atmosphere using an electron beam irradiation device (EC series, manufactured by ENERGY SCIENCES, INC.) at the irradiation doses (30, 60, 300 kGy) shown in Table 3. To evaluate the adhesion of the printed materials for Examples 4-7 and Comparative Examples 4-8, cellophane tape peel tests and solvent tests were performed according to the following methods.

[0519] [Cellophane tape peel test] A cellophane tape peel test was performed in the same manner as in the cellophane tape peel test of Test Example 2, and evaluated according to the following criteria.

[0520] <Judgment criteria> A: Ink retention rate of 95% or more B: Ink remaining percentage is 70% or more but less than 95% C: Ink remaining percentage is less than 70%

[0521] [Solvent Test] Ethyl acetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Wako Grade 1) was used as the solvent. A cotton swab was immersed in the solvent, and the surface of the ink layer was rubbed twice with the swab. It was visually checked whether or not ink adhered to the cotton swab. If no ink adhered to the cotton swab, it was evaluated as "no" ink removal (detachment of ink from the ink layer). If ink adhered to the cotton swab, it was evaluated as "yes" ink removal (detachment of ink from the ink layer). The results are shown in Table 3.

[0522] [Table 3]

[0523] As shown in Table 3, Examples 4 to 6, which used a PET film having the above-mentioned easy-adhesion layer as the base layer, all received a rating of "B" or higher (ink retention rate of 75% or more) in the cellophane tape peel test, regardless of the EB irradiation dose. This demonstrates that EB irradiation can improve the adhesion between the base layer and the ink layer. From this, it can be concluded that when the base layer is a PET film having the above-mentioned easy-adhesion layer, it has a high affinity with the electron beam (EB) curable resin contained in the ink layer, regardless of the EB irradiation dose. Furthermore, it was shown that by setting the EB irradiation dose to 300 kGy or higher, there was no ink removal not only in the cellophane tape peel test but also in the solvent test, demonstrating that adhesion can be further improved. When a PET film with a corona-treated surface is used as the base layer, as shown in Comparative Examples 4 and 5, by forming an ink layer on the corona-treated surface and setting the EB irradiation dose to 300 kGy or higher, it was shown that no ink was removed in the solvent test. From this, it is considered that when the base layer is a PET film with a corona-treated surface and an ink layer is formed on the corona-treated surface, setting the EB irradiation dose within a specific range will result in affinity with the electron beam (EB) curable resin contained in the ink layer. Even when the substrate layer has a corona-treated surface, as shown in Comparative Examples 6-8, when an ink layer is formed on the untreated surface, it was shown that even increasing the EB irradiation dose to 300 kGy did not improve adhesion in both the cellophane tape peel test and the solvent test. From this, it is considered that when a substrate layer with an untreated surface has an ink layer formed on the untreated surface and the EB irradiation dose is set within a specific range, the affinity with the electron beam-curable resin contained in the ink layer does not increase. In Examples 4 to 7, the adhesion between the substrate layer and the ink layer can be further improved by laminating a modified layer on top of the ink layer. Similarly, in Comparative Examples 4 to 8, the adhesion between the substrate layer and the ink layer can also be improved by laminating a modified layer on top of the ink layer.

[0524] [Test Example 4] Evaluation of adhesion between the substrate layer and the ink layer based on the type of substrate layer and modified layer. PET film and NY film were used as the base layer. Specifically, for the PET film, in Examples 8-10 and Comparative Examples 9 and 10, a PET film with an easy-adhesion layer (manufactured by Unitika Ltd., product name: Emblet PTM, thickness 12 μm), similar to that used in Test Example 2, was used. For Examples 11 and 12, an NY film with an acrylic resin layer as the easy-adhesion layer (manufactured by Unitika Ltd., product name: Emblem ONM, thickness 15 μm) was used. Using an offset printing press (COMEXI, CI-8), the predetermined printing was performed on the surface of each easy-adhesion layer using water-based offset printing with dampening solution, employing an ink containing electron beam (EB) curable resin. The ink used was a thermoplastic resin containing a copolymer of ethylene acrylic acid and ethylene methacrylic acid. The ink colors used were black (K) and white (W), as shown in Table 4. In Table 4, "KWW," etc., indicate that the layers were applied in that order from left to right, starting from the base layer side. The ink coverage rate for each color was adjusted by printing each color in layers using a solid plate on an offset printing press. The ink coverage rate was 300%.

[0525] After printing, the print was irradiated with an electron beam (EB) at a dose of 45 kGy from the ink layer side using an electron beam irradiation device (EC series, manufactured by ENERGY SCIENCES, INC.) under a nitrogen atmosphere.

[0526] In Example 8, after EB irradiation, the ink modifier was applied to the cured ink layer using a bar coater, and the diluted solvent was dried and vaporized in an electric dryer (FS-45W, manufactured by Tokyo Glass Equipment Co., Ltd.) at 100°C for 1 minute to form a modified layer. Similar to Test Example 1, the ink modifier was prepared by blending an aliphatic polyester polyol (manufactured by Mitsui Chemicals, Inc., trade name: Takelac A626, sometimes referred to as "(C)") as the main component, polyisocyanate (manufactured by Mitsui Chemicals, Inc., trade name: Takenate A50, sometimes referred to as "(D)") as the curing agent, and ethyl acetate as the solvent, to prepare an ink modifier with a solid content of 36.5% by mass. The mass-based blending ratio (by mass) of each component was (C):(D)=8:1. The application amount of the modified layer was 3.0 g / m².2 The settings were then adjusted. Next, using a laminating device, an LLDPE film (manufactured by Futamura Chemical Co., Ltd., LL-XMTN) was laminated onto the modified layer as a sealant layer (thickness 70 μm) to produce the printed material of Example 8.

[0527] In Example 9, after EB irradiation, the ink modifier was applied to the cured ink layer using a bar coater, and the diluted solvent was dried and vaporized in an electric dryer (FS-45W, manufactured by Tokyo Glass Equipment Co., Ltd.) at 100°C for 1 minute to form a modified layer. The ink modifier was prepared by blending polyether polyol (manufactured by Mitsui Chemicals, Inc., trade name: Takelac A953) as the main ingredient, aromatic polyisocyanate (manufactured by Mitsui Chemicals, Inc., trade name: Takenate A93) as the curing agent, and ethyl acetate as the solvent, and mixing them to prepare an ink modifier with a solid content concentration of 33% by mass as a resin for dry lamination. The amount of modified layer applied was 3.0 g / m². 2 The settings were then adjusted. Next, in the same manner as in Example 8, an LLDPE film (LL-XMTN, manufactured by Futamura Chemical Co., Ltd.) was laminated on the modified layer as a sealant layer (thickness 70 μm) to produce the printed material of Example 9.

[0528] After EB irradiation, in Comparative Example 9, an adhesive was applied to the cured ink layer using a bar coater device, and then, in the same manner as in Example 8, an LLDPE film (LL-XMTN, manufactured by Futamura Chemical Co., Ltd.) was laminated as a sealant layer and left to stand for 24 hours to produce the printed material of Comparative Example 9.

[0529] After EB irradiation, in Example 10, an ink modifier was applied to the cured ink layer using a bar coater, and the diluted solvent was dried and vaporized in an electric dryer (FS-45W, manufactured by Tokyo Glass Equipment Co., Ltd.) at 100°C for 1 minute to form a modified layer. The ink modifier was prepared by compounding a polybutadiene-based anchor coat (AC) agent (Toyo Morton Co., Ltd., EL-451) containing a polybutadiene-based resin with isopropanol (IPA) and water as solvents to prepare an ink modifier with a solid content concentration of 1.5% by mass. The amount of the modified layer applied was 3.0 g / m².2 The settings were then adjusted. Next, an extruded resin layer (20 μm thick) was formed as a sealant layer by extruding polyethylene (Novatec LD LC600A, manufactured by Nippon Polyethylene Co., Ltd.) onto the modified layer using an extrusion laminating apparatus, thereby producing the printed material of Example 10.

[0530] After EB irradiation, in Comparative Example 10, without laminating either a modified layer or an adhesive layer on the cured ink layer, an extruded resin layer (20 μm thick) was directly formed as a sealant layer in the same manner as in Example 10, thereby producing the printed material of Comparative Example 10.

[0531] After EB irradiation, in Example 11, a modified layer (using an aliphatic polyester polyol as the main ingredient and an aromatic polyisocyanate as the curing agent) was laminated on the cured ink layer in the same manner as in Example 8, and an extruded resin layer (Novatec LD LC600A) was laminated on the modified layer as a sealant layer to produce the printed material of Example 11.

[0532] After EB irradiation, in Example 12, a modified layer (using a polybutadiene-based anchor coat (AC) agent containing a polybutadiene-based resin as the ink modifier) ​​was laminated on the cured ink layer in the same manner as in Example 10, and an LLDPE film was laminated on the modified layer as a sealant layer to produce the printed material of Example 12.

[0533] To evaluate the adhesion of the printed materials from Examples 8-12 and Comparative Examples 9 and 10, lamination strength tests and lifting tests were performed according to the following methods.

[0534] [Laminate strength (adhesion strength) test] In accordance with JIS K 6854-2:1999, a tensile testing machine (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name: Strograph VE10D) was used to cut the printed materials of Examples 8-12 and Comparative Examples 9 and 10 into 15 mm wide strips to serve as measurement samples. After peeling the interlayer (between the ink layer and the modified layer) at the edges of the measurement samples, the peel strength was measured at an angle of 90° (total 180°), a tensile speed of 300 mm / min, and at room temperature. This peel strength was then determined as the adhesive strength at room temperature (20°C). The results are shown in Table 4.

[0535] [Measurement of buoyancy] The printed materials of Examples 8-12 and Comparative Examples 9 and 10 were held in the hands of the testers, and with both hands overlapping, the printed materials were rubbed together (once) while moving one hand (e.g., the right hand) forward and the other hand (e.g., the left hand) backward. Then, the printed materials were rubbed together again (twice) while moving the right hand backward and the left hand forward. This was repeated a total of 10 times to loosen the printed materials. After that, the presence or absence of lifting between the layers of the printed material was checked visually. The results are shown in Table 4.

[0536] [Table 4]

[0537] As shown in Table 4, the printed materials of Examples 8 to 12 exhibited high lamination strength (adhesion strength), and no lifting was observed. This indicates that, regardless of whether PET film or NY film is used as the base layer, adhesion can be improved by laminating a modified layer containing urethane resin or polybutadiene resin onto these base layers. Furthermore, this suggests that the resin layers containing urethane resin and polybutadiene resin in Examples 8 to 12 function as modified layers.

[0538] In contrast, the printed material of Comparative Example 9 showed low lamination strength and also exhibited delamination. From a comparison of Comparative Example 9 with Examples 8-12, it is understood that the resin layer (adhesive layer) containing cyanoacrylate resin does not function as a modifying layer. The printed material of Comparative Example 10 also showed low lamination strength and also exhibited delamination. From a comparison of Comparative Example 10 with Examples 8-12, it is understood that providing a modifying layer can improve the adhesion of printed materials.

[0539] [Test Example 5] Evaluation of defect suppression during twisting of the base layer and ink layer depending on the type of base layer and modified layer. Of the printed materials of Examples 8-12, which were evaluated as having high adhesion in Test Example 4 above, the printed materials of Examples 8 and 10-12 were subjected to a laminate strength test again in the same manner as in Test Example 4 above, and the loop stiffness was measured according to the method described below. In addition, a pinhole test was performed to evaluate the suppression of defects during twisting. The results are shown in Table 5.

[0540] [Measurement of loop stiffness] The printed materials from Examples 8, 10-12 were cut into 180mm x 15mm rectangles to serve as test specimens. Using a loop stiffness measuring instrument (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name: Loop Stiffness Tester DA), the loop stiffness in the TD direction was measured for each test specimen under the following conditions: test width 100mm, speed: 3.3mm / second, time 3 seconds.

[0541] [Pinhole test] A Gelboflex testing apparatus was prepared and used, comprising a pair of circular discs with a diameter of 90 mm, in which a printed material measuring 300 mm in length and 200 mm in width is rolled into a cylindrical shape, with both ends in the longitudinal direction fixed to the circumferential surface. One circular disc (fixed circular disc) is fixed so as not to move, while the other circular disc (movable circular disc) is positioned at a predetermined distance from the fixed circular disc (the position where the cylindrical printed material is extended) (initial position). From the initial position, it rotates 440° in one direction around the central axis (for example clockwise) while approaching the fixed circular disc by 150 mm in the longitudinal direction (150 mm from the initial position) (approach position), and then rotates 440° (-440°) in the opposite direction (for example counterclockwise) to return to the initial position (enabling bending linear motion). Of the printed materials of Examples 8 to 12, the printed materials of Examples 8 and 10 to 12 were cut to a length of 300 mm and a width of 200 mm. Each printed material was rolled into a cylindrical shape, and both ends of the cylindrical printed material in the longitudinal direction were fixed to the circumferential surfaces of a fixed circular disc and a movable circular disc, respectively. The movable circular disc was rotated 440° around its central axis (twisting the printed material) and moved 150mm closer to the fixed circular disc to a proximity position. Then, the movable circular disc was rotated 440° (-440°) in the opposite direction from the proximity position (reversing the twist of the printed material) and moved back to its initial position. This operation, from the time the movable circular disc moved from the initial position to the proximity position and then back to the initial position, was considered one operation. After repeating this operation 1500 times, the presence or absence of pinholes was checked visually.

[0542] [Table 5]

[0543] As shown in Table 5, similar to Test Example 4 above, the printed materials of Examples 8, 10-12 showed high adhesion. Furthermore, it was shown that the greater the loop stiffness in the TD direction of the printed material (stronger stiffness), the more likely pinholes were to occur. In other words, the smaller the loop stiffness in the TD direction of the printed material (weaker stiffness), the less likely pinholes were to occur. Thus, it was found that even in printed materials with improved adhesion due to EB irradiation, differences in stiffness (loop stiffness) resulted in differences in the occurrence rate of pinhole defects. The mechanism by which such defects occur is thought to be that in printed materials with high loop stiffness, the bent parts are more likely to fold at a sharp angle when twisting occurs, and this folding causes pinholes and lifting. Also, because the folded parts are hard, pinholes are more likely to occur when rubbed. It was found that by applying EB irradiation to a laminate of an ink layer and a substrate layer having affinity with the ink layer, and then laminating a modified layer containing a urethane ...

Claims

1. A printed material that has been offset printed using an active energy ray curable ink containing an active energy ray curable resin, An ink layer containing the aforementioned active energy ray curable ink, A substrate layer having affinity for the active energy ray curable resin, A modifying layer that modifies the aforementioned ink layer and Equipped with, The substrate layer is a printed material including an easily adhesive layer having an acrylic resin layer.

2. The printed material according to claim 1, wherein the modified layer comprises a urethane resin.

3. The printed article according to claim 2, further comprising a sealant layer on the side of the modified layer opposite to the ink layer.

4. The printed material according to claim 1, wherein the modified layer comprises an acrylic resin.

5. The printed material according to claim 4, further comprising a sealant layer via an adhesive layer on the side of the substrate layer opposite to the ink layer.

6. A printed material according to any one of claims 1 to 5, which is irradiated with active energy rays.

7. A printing medium suitable for offset printing using an active energy ray curable ink containing an active energy ray curable resin, The substrate layer comprises at least an active energy ray curable resin having affinity for it. The substrate layer includes an easily adhesive layer having an acrylic resin layer, and is configured to improve adhesion with the active energy ray curable resin by irradiation with active energy rays.

8. The printing medium according to claim 7, wherein the activated energy beam has an accelerating voltage of 120 kV or less and an irradiation dose of 25 to 50 kGy.

9. A package formed from the printed material described in claim 1 or the printing medium described in claim 7.

Images