Printed film and method for producing the same, laminate and method for producing the same, packaging film, and packaging bag

Abstract

To provide a printed film that makes it possible to obtain a laminate in which occurrence of blocking is suppressed and which is improved in poor appearance caused by bubbles.SOLUTION: A printed film 1 comprises a base film 11 and a printed layer 12 provided on the base film 11, wherein, when viewed from above on the printed layer 12 side of the base film 11, the printed layer 12 includes a colored region 13 containing a coloring pigment and a transparent region 14 containing no coloring pigment, the transparent region 14 being composed of a plurality of dots, an average area of the dots being 0.005 to 0.018 mm2, and an area ratio of the transparent region 14 occupying a region other than the colored region 13 on the base film 11 being 10 to 50%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a printed film and a method for manufacturing the same, a laminate and a method for manufacturing the same, a packaging film, and a packaging bag. [Background technology]

[0002] As part of efforts to address environmental issues, packaging bags made of plastic film (e.g., flexible packaging bags) are becoming popular as a replacement for bottles and cans. Packaging bags often consist of a laminate made by bonding two or more films with an adhesive to improve their performance, such as strength, water resistance, moisture resistance, gas barrier properties against oxygen and other gases, and heat resistance. Furthermore, when a packaging bag is made of a laminate including a film with a printed layer (printed film), the printed layer is usually provided on the inner surface of the laminate that constitutes the packaging bag in order to prevent ink from being scraped off due to wear and to prevent ink transfer when multiple packaging bags are stacked (see, for example, Patent Document 1, etc.).

[0003] In such a laminate, bubbles may form in the adhesive layer due to the step between the printed layer and the base film, and these bubbles may cause poor appearance. This poor appearance occurs more significantly when a film with high gas barrier properties is attached. Regarding the poor appearance caused by the bubbles, for example, Patent Document 2 describes that the poor appearance caused by the bubbles can be improved by forming a transparent ink layer in an area where no colored ink layer is formed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6973690 [Patent Document 2] Patent application 2022-111084 Summary of the Invention [Problem to be solved by the invention]

[0005] Typically, printed films are wound into rolls and stored before the lamination process. However, in the laminate produced by the method described in Patent Document 2, the clear ink layer does not contain color pigments and has a smoother surface than the colored ink layers. Therefore, if the printed film is wound into a roll and stored before the lamination process, the winding pressure applied to the film surface can easily cause the top surface of the printed film (the surface facing the printed layer) to stick to the back surface (the surface facing the base film), a phenomenon known as blocking. This phenomenon is particularly noticeable when the storage period between the production of the printed film and the lamination process is long.

[0006] Therefore, the present disclosure aims to provide a printed film and a method for manufacturing the same that can produce a laminate that is less prone to blocking and has improved appearance defects due to air bubbles, to provide a laminate including the printed film and a method for manufacturing the same, and to provide a packaging film including the laminate and a packaging bag made from the packaging film. [Means for solving the problem]

[0007] The present disclosure provides at least the following [1] to [8].

[0008] [1] A substrate film and a printing layer provided on the substrate film, When viewed from above the printed layer side of the base film, the printed layer includes a colored region containing a color pigment and a transparent region not containing a color pigment, the transparent area is made up of a plurality of dots, The average area of ​​the dots is 0.005 to 0.018 mm 2 and A printed film, wherein the area ratio of the transparent region to the area other than the colored region on the base film is 10 to 50%.

[0009] [2] The printed film according to [1], wherein the base film has a gas barrier layer.

[0010] [3] a first film, an adhesive layer, and a second film in this order; The first film is the printed film according to [1] or [2], The adhesive layer is disposed on the printed layer of the first film.

[0011] [4] The laminate according to [3], wherein the adhesive layer is formed of a solventless adhesive.

[0012] [5] A packaging film comprising the laminate according to [3] or [4].

[0013] [6] A packaging bag made from the packaging film described in [5].

[0014] [7] forming a printing layer on a substrate film; The process comprises: A step (a) of printing color inks on the base film to form colored areas; and (b) a step of printing a transparent ink on an area on the base film other than the area where the colored area is to be formed, to form a dot-shaped transparent area, In the above step, the average area of ​​the dots constituting the transparent region is 0.005 to 0.018 mm 2 and the printed layer is formed so that the area ratio of the transparent region to the area other than the colored region on the base film is 10 to 50%.

[0015] [8] A step of preparing, as a first film, the printed film according to [1] or [2], or a printed film obtained by the manufacturing method according to [7]; and placing a second film on the printed layer of the first film via an adhesive layer. [Effects of the Invention]

[0016] According to the present disclosure, it is possible to provide a printed film and a method for manufacturing the same that can produce a laminate that is less susceptible to blocking and has improved appearance defects due to air bubbles. Also, according to the present disclosure, it is possible to provide a laminate including the printed film and a method for manufacturing the same. Furthermore, according to the present disclosure, it is possible to provide a packaging film including the laminate and a packaging bag made from the packaging film. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of the printed film of the present disclosure. [Figure 2] FIG. 2 is a plan view of the printed film of FIG. 1, viewed from above the printed layer side of the base film. [Figure 3] FIG. 3(a) is a schematic cross-sectional view showing one embodiment of a laminate of the present disclosure, and FIG. 3(b) is a partially enlarged cross-sectional view of the laminate of FIG. 3(a). [Figure 4] FIG. 4 is a schematic cross-sectional view showing another embodiment of the laminate of the present disclosure. [Figure 5] FIG. 5 is a schematic cross-sectional view for explaining a method for producing the printed film of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. Furthermore, unless specifically stated otherwise, the units of the numerical values ​​before and after "to" are the same. In the numerical ranges described in stages in this specification, the upper or lower limit of a numerical range in a certain stage may be replaced with the upper or lower limit of a numerical range in another stage. Furthermore, in the numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with a value shown in the examples. Furthermore, the upper and lower limits described individually can be combined in any combination.

[0019] Hereinafter, embodiments of the present disclosure will be described in detail, with reference to the drawings as needed. However, the present disclosure is not limited to the following embodiments.

[0020] <Printed film> Figure 1 is a schematic cross-sectional view showing one embodiment of a printed film of the present disclosure. The printed film 1 in Figure 1 has a base film 11 and a printed layer 12 provided on the base film 11. The thickness of the printed film 1 is, for example, 10 to 80 µm, and may be 10 to 60 µm.

[0021] Fig. 2 is a plan view of the printed film 1 of Fig. 1, viewed from above the printed layer 12 side of the base film 11. As shown in Fig. 2, when viewed from above the printed layer 12 side of the base film 11, the printed layer 12 includes a colored region 13 containing a color pigment and a transparent region 14 not containing a color pigment. The transparent region 14 is made up of a plurality of dots, and the average area of ​​the dots is 0.005 to 0.018 mm 2 The area ratio of the transparent region 14 to the area other than the colored region 13 on the base film 11 is 10 to 50%.

[0022] The printed film 1 is less likely to suffer from poor appearance due to air bubbles during laminate production and is less likely to suffer from blocking due to the transparent regions. This is presumably because the inclusion of the transparent regions 14 in the printed layer 12 reduces the level difference between the base film 11 and the printed layer 12, suppressing the generation of air bubbles in the adhesive layer, and because the transparent regions 14 are composed of a plurality of dots having the above-mentioned specific average area and have the above-mentioned specific area ratio, the contact surface between the base film 11 and the transparent regions 14 during winding is reduced and dispersed.

[0023] (Base film) The base film 11 may be any film on which the printed layer 12 can be formed, and may be, for example, a resin film such as a biaxially stretched resin film. Examples of resin films that can be used include biaxially stretched films of polyesters such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polyamides such as nylon, polypropylene, polystyrene, polyimide, polyvinyl alcohol, polyvinyl chloride, and ethylene-vinyl alcohol copolymers, and composite films formed by laminating two or more of these films. The base film 11 may also be a biaxially stretched resin film laminated with a non-stretched resin film.

[0024] The resin film may be transparent so as to be able to display a pattern formed by the printing layer 12. In this specification, the film being transparent means that the total light transmittance of the film measured in accordance with JIS K7361-1:1997 using a color and turbidity simultaneous measuring device ("COH400" manufactured by Nippon Denshoku Industries Co., Ltd.) is 85% or more.

[0025] The thickness of the resin film is, for example, 10 to 60 μm.

[0026] Although not shown, the base film 11 may have a gas barrier layer. That is, the printed film 1 may be a gas barrier film including the printed layer 12.

[0027] The gas barrier layer is a layer that has barrier properties against gases such as oxygen gas and water vapor. The gas barrier layer may be a layer that has oxygen barrier properties, or a layer that has water vapor barrier properties. Here, the term "oxygen barrier properties" means that the layer has oxygen barrier properties in accordance with JIS K7126-2 (2006), as measured using an oxygen transmission rate measuring device ("OX-TRAN2 / 21" manufactured by MOCON) under conditions of 25°C and 80% relative humidity (OTR, unit: cc / m 2 / day / atm) is 2cc / m 2 / day / atm or less. In addition, the layer having water vapor barrier properties means that the water vapor transmission rate (WVTR, unit: g / m) measured under conditions of 40°C and 90% relative humidity using a water vapor transmission rate measuring device (Technolox "DELTAPERM") in accordance with JIS K7129-5 (2016). 2 / day) is 1.0g / m 2 This means that it is less than or equal to / day.

[0028] The gas barrier layer may be a layer made of metal foil (metal foil layer) or a layer made of a vapor-deposited film of an inorganic material (inorganic vapor-deposited layer). The gas barrier layer may contain one of these layers alone, or may have a layered structure containing two or more of them.

[0029] The metal foil layer is formed, for example, by laminating a resin film with one of these metal foils. Examples of the metal foil include metal foils made of various metals such as aluminum, stainless steel, and copper.

[0030] The inorganic vapor deposition layer is formed by vapor-depositing an inorganic material onto a resin film. Examples of inorganic materials include metals and metal oxides. Examples of metals include aluminum, stainless steel, and copper. Examples of metal oxides include silicon oxide and aluminum oxide. Methods for forming the inorganic vapor deposition layer include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition (CVD) methods such as plasma-enhanced chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition.

[0031] The gas barrier layer may be transparent so as to be able to display a pattern formed by the print layer 12. The gas barrier layer may be, for example, a transparent inorganic vapor deposition layer (transparent vapor deposition layer).

[0032] The thickness of the gas barrier layer is, for example, 0.001 to 10 μm.

[0033] The base film 11 may include other functional layers such as a shielding layer depending on the intended use.

[0034] The thickness of the substrate film 11 is, for example, 10 to 70 μm, and may be 10 to 60 μm.

[0035] (Printing layer) The printed layer 12 is a layer formed by printing and includes a colored region 13 and a transparent region 14. The colored region 13 is a region that contains a color pigment and is therefore visible as colored in a planar view, and is formed in a specific region on the base film 11. The transparent region 14 is a region that does not contain a color pigment and is therefore visible as transparent in a planar view, and is formed in a part of an area on the base film 11 other than the area where the colored region 13 is formed (an area where the colored region 13 is not formed). Note that the colored region 13 refers not only to the surface of the printed layer 12 corresponding to that region, but also to the part that overlaps with that surface in a planar view (the entire part located on the base film 11). The same applies to the transparent region 14.

[0036] The colored region 13 is formed, for example, with colored inks. The colored inks used as printing materials and the colored inks contained in the printed layer may have different compositions due to the influence of the layer formation process, such as drying and curing, but for convenience, these will be collectively referred to as colored inks in this specification. The same applies to transparent inks.

[0037] As the color ink, general gravure ink or flexographic ink can be used, and vegetable oil ink, biomass ink, etc. can also be used.

[0038] Color inks typically contain a color pigment and a binder resin. Either inorganic or organic pigments may be used as the color pigment. The type of color pigment may be determined appropriately depending on the color to be expressed. A combination of multiple types of color pigments may be used. That is, the colored region 13 may contain multiple types (multiple colors) of color pigments. Known binder resins used in inks may be used as the binder resin. For example, when the color ink is an oil-based gravure ink, a mixture of a urethane resin and a vinyl chloride-vinyl acetate copolymer resin may be used as the binder resin.

[0039] The color ink may contain various additives other than the color pigment and binder resin, as well as a solvent (for example, a volatile organic solvent). The solvent may be removed by drying when the colored region 13 is formed.

[0040] As shown in FIG. 1 , the colored region 13 may have a step on its surface 13a. When the colored region 13 has an overlapping portion of the colored inks, a portion where the colored inks overlap heavily (thick portion) and a portion where the colored inks overlap less (thin portion) are formed, forming a step on the surface 13a of the colored region 13. The size (maximum value) of the step on the surface 13a of the colored region 13 is, for example, 0.5 to 10 μm, and may be 1 to 10 μm or 0.5 to 9.5 μm. The step can also be referred to as the difference between the thickness of the thickest portion of the colored region 13 and the thickness of the thinnest portion of the colored region 13. The thickness of the thickest portion of the colored region 13 is, for example, 1 to 10.5 μm, and may be 1.5 to 10.5 μm or 1 to 10 μm. The thickness of the thinnest portion of the colored region 13 is, for example, 0.5 to 10 μm, and may be 0.5 to 5 μm.

[0041] The colored region 13 may consist solely of a layer formed of a colored ink (hereinafter referred to as a "colored ink layer"), or may include a layer formed of a transparent ink (hereinafter referred to as a "transparent ink layer") in the thickness direction. For example, the transparent ink layer may be formed so as to fill in some or all of the steps on the surface of the colored ink layer. The arrangement of the colored ink layer and the transparent ink layer in the thickness direction is not particularly limited, but from the viewpoint of further reducing blocking, it is preferable that the outermost surface of the colored region 13 (the surface opposite to the base film 11) be formed of a colored ink layer.

[0042] The area ratio of the colored region 13 to the entire area on the base film 11 (the proportion of the colored region 13 to the entire area on the base film 11 when observed in a planar view) is not particularly limited and is determined according to the type of pattern expressed by the printing layer 12.

[0043] The thickness of the colored region 13 is, for example, 1 to 10 μm. The thickness of the colored region 13 can be determined, for example, by measuring the thickness at 30 randomly selected points and averaging these measurements.

[0044] The transparent region 14 is composed of a plurality of dots formed with transparent ink. The transparent ink contains, for example, a resin component. As the resin component, a binder resin (so-called medium) used in preparing general gravure ink or flexographic ink can be used. As the binder resin, for example, a mixture of urethane resin and vinyl chloride-vinyl acetate copolymer resin, which is the binder resin of oil-based gravure ink, can be used.

[0045] The clear ink may contain non-color-impacting clear pigments such as barium sulfate (eg, precipitated barium sulfate), calcium carbonate, silica, and the like.

[0046] From the viewpoint of not affecting the color and visibility of the image expressed by the color inks, it is preferable to use a transparent ink that can form a 5 μm thick layer with a total light transmittance of 85% or more and a haze value of 20% or less. Here, the total light transmittance of the layer is a value measured in accordance with JIS K7361-1:1997, and the haze value of the layer is a value measured in accordance with JIS K7136:2000.

[0047] The dots have a shape that protrudes upward from the printing layer side. In Fig. 1, the cross section of the dots is semicircular, but the cross section of the dots is not particularly limited and may be polygonal (for example, trapezoidal), etc. Also, in Fig. 2, the dots are circular in plan view, but the planar shape of the dots is not particularly limited and may be elliptical, polygonal, etc.

[0048] The average area of ​​the dots is 0.005 mm to further suppress the generation of bubbles. 2 From the same viewpoint, the average area of ​​the dots is 0.007 mm 2 or more than 0.010mm 2 The average area of ​​the dots may be 0.018 mm or more from the viewpoint of further suppressing the occurrence of blocking. 2 From the same perspective, 0.015mm 2 Less than or equal to 0.012 mm 2 From these viewpoints, the average area of ​​the dots may be 0.005 to 0.018 mm 2 , 0.007~0.015mm 2 or 0.010~0.012mm 2 The average area of ​​the dots can be determined, for example, by measuring the areas of 30 dots randomly observed from above the print layer side of the first film using a microscope and averaging these areas.

[0049] The average dot height is, for example, 0.5 to 10 μm, the maximum dot height (height of the highest dot) is, for example, 1 to 10 μm, the minimum dot height (height of the lowest dot) is, for example, 0.5 to 5 μm, and the difference between the maximum and minimum dot heights (difference in height between the highest and lowest dots) is, for example, 0.5 to 5 μm. The average dot height can be determined, for example, by measuring the heights of 30 randomly observed dots (maximum values ​​in the thickness direction as observed from the front) and averaging these. The average dot height can also be referred to as the thickness of the transparent region 14.

[0050] The multiple dots constituting the transparent region 14 may be arranged regularly or irregularly. The arrangement of the multiple dots constituting the transparent region may be, for example, a square lattice pattern, a diagonal lattice pattern, a hexagonal lattice pattern, or the like.

[0051] Of the multiple dots that form the transparent region 14, the center-to-center distance between two adjacent dots is, for example, 0.1 to 0.3 mm.

[0052] The area ratio of the transparent regions 14 to the areas other than the colored regions 13 on the base film 11 is 10% or more, and may be 15% or more or 20% or more from the viewpoint of further suppressing the generation of bubbles. The area ratio of the transparent regions 14 is 50% or less, and may be 40% or less or 30% or less from the viewpoint of further suppressing the generation of blocking. From these viewpoints, the area ratio of the transparent regions 14 may be 15 to 40% or 20 to 30%. The area ratio of the transparent regions 14 is determined by randomly selecting 30 5 mm square regions from the areas other than the colored regions 13 and averaging the area ratios of these regions. From the viewpoint of more significantly achieving the above-mentioned effect, it is preferable that there are no 5 mm square regions in the areas other than the colored regions 13 where the area ratio of the transparent regions 14 is less than 10% and more than 50%.

[0053] The transparent region 14 may be formed to a thickness similar to that of the colored region 13. The value Δd obtained by subtracting the average thickness of the transparent region 14 from the thickness of the thickest portion of the colored region 13 may be 1.0 μm or less, 0.5 μm or less, or 0.1 μm or less, from the viewpoint of further suppressing the occurrence of bubbles. Δd may be a negative value. That is, the average thickness of the transparent region 14 may be greater than the thickness of the thickest portion of the colored region 13. Δd may be −1.0 μm or more, −0.5 μm or more, or 0 μm or more, from the viewpoint of further suppressing the occurrence of blocking. From these viewpoints, Δd may be −1.0 to 1.0 μm, −0.5 to 0.5 μm, or 0 to 0.1 μm.

[0054] <Laminate> Fig. 3(a) is a schematic cross-sectional view showing one embodiment of a laminate of the present disclosure, and Fig. 3(b) is a partially enlarged cross-sectional view of the laminate of Fig. 3(a). The laminate 100A shown in Fig. 3(a) and (b) has, in this order, a first film, an adhesive layer S1, and a second film 2. The thickness of the laminate 100A may be, for example, 20 to 285 µm, or may be 20 to 100 µm.

[0055] (First film) The first film is the printed film 1 of the above embodiment, and has a base film 11 and a printed layer 12 including colored regions 13 and transparent regions 14 .

[0056] (Second film) The second film 2 may be a known film used for packaging bags, such as an impact-resistant film or a sealant film. Examples of impact-resistant films include biaxially oriented nylon films and biaxially oriented polypropylene films. Examples of sealant films include unstretched polypropylene films. The second film 2 may include a gas barrier layer. Examples of the gas barrier layer are the same as the examples of the barrier layer that the base film 11 may have.

[0057] The surface of the second film 2 on the side of the printed layer 12 is preferably flat, from the viewpoint of more effectively suppressing appearance defects such as poor adhesion and air bubbles trapped in uneven portions of the laminate. Here, a flat surface means that the maximum waviness height Wz (maximum waviness height of the waviness curve element when a cutoff value (λc = 0.8 mm) is applied) measured in accordance with JIS B0601:2013 is 2.0 μm or less. From the viewpoint of providing the laminate 100A with a better appearance, it is also preferable that the surface of the second film 2 opposite the side of the printed layer 12 is flat.

[0058] The thickness of the second film 2 is, for example, 10 to 200 μm.

[0059] (adhesive layer) The adhesive layer S1 is disposed on the printed layer 12 of the first film, and is provided so as to fill in any unevenness on the surface of the printed layer 12 and in any area on the base film 11 where the printed layer 12 is not formed.

[0060] The adhesive layer S1 may be formed of a solvent-based adhesive or a solventless adhesive. Solventless adhesives have the advantage of having a low environmental impact during the manufacturing process and can be applied thinner than solvent-based adhesives. Therefore, adhesive layers formed with solventless adhesives tend to be thinner. In conventional laminates, when a thin adhesive layer is formed using a solventless adhesive, there is a problem that air bubbles are more likely to form in the adhesive layer, resulting in poor appearance, compared to when a solvent-based adhesive is used. However, in this embodiment, the printed film 1 is used as the first film, so a laminate with good appearance is more likely to be obtained even when a solventless adhesive is used to form a thin adhesive layer S1.

[0061] Examples of solvent-free adhesives include two-component curing polyurethane adhesives in which a base material such as polyester polyol, polyether polyol, or acrylic polyol is reacted with an aromatic or aliphatic isocyanate compound having two or more functional groups as a curing agent. Such adhesives react with heat or the like to harden (for example, the hydroxyl groups of the base material react with the isocyanate groups of the curing agent), thereby forming an adhesive layer. In other words, the adhesive layer can be said to consist of a reaction-cured product of the solvent-free adhesive.

[0062] The thickness of the adhesive layer S1 is, for example, 0.3 to 5 μm.

[0063] The laminate 100A described above can be suitably used, for example, to form a packaging bag (e.g., a flexible packaging bag) for packaging contents. When the laminate 100A includes a sealant film, the laminate 100A can be used as a packaging film as is. When the laminate 100A does not include a sealant film, a sealant film can be attached to the laminate 100A to form a packaging film. Specifically, a packaging bag can be manufactured by attaching sealant films of packaging films including the laminate 100A to each other and processing them into a bag. Examples of contents include liquids such as liquid seasonings, toiletries, soups, and liquid detergents; solids such as simmered dishes; and solid-liquid mixtures of liquids and solids such as curry.

[0064] The laminate 100A provides a packaging film that is less susceptible to defects in appearance caused by air bubbles generated in the adhesive layer due to the printed layer during the manufacturing process of a packaging bag. Furthermore, the laminate 100A can be said to be a laminate that suppresses defects such as defects in appearance caused by air bubbles generated in the adhesive layer due to the printed layer.

[0065] Although one embodiment of the laminate of the present disclosure has been described above, the laminate of the present disclosure is not limited to the above embodiment.

[0066] Fig. 4 is a schematic cross-sectional view showing another embodiment of a laminate of the present disclosure. The laminate 100B shown in Fig. 4 includes a third film 3 in addition to a first film (printed film 1) and a second film 2. The third film 3 is disposed on the second film 2 (i.e., on the opposite side of the second film 2 from the first film) via an adhesive layer S2.

[0067] As shown in the laminate 100B of FIG. 4, the laminate of the present disclosure may further include one or more other films (a third film 3 in FIG. 4) in addition to the first and second films to provide the required mechanical strength, barrier properties, light resistance, ease of opening, etc., for a packaging bag. The other film may be disposed on the opposite side of the second film from the first film, or on the opposite side of the first film from the second film. The type of the other film is not particularly limited, and the films exemplified as the second film can be used. However, when the laminate includes a sealant film, it is preferable that the film constituting the outermost layer (one of the two outermost layers) of the laminate be the sealant film. An adhesive layer (adhesive layer S2 in FIG. 4) may be used to laminate the other film. The details of the adhesive layer used to laminate the other film are the same as those of the adhesive layer S1 between the first film (printed film 1) and the second film 2 in the laminate 100A.

[0068] <Packaging bag> A packaging bag according to one embodiment of the present disclosure is a packaging bag (e.g., a flexible packaging bag) made by manufacturing a packaging film including the laminate of the above embodiment (e.g., laminates 100A and 100B). The packaging film is, for example, a film having one outermost layer made of a sealant film. With a packaging film having such a configuration, a packaging bag can be manufactured by laminating the sealant films of the packaging film together and processing them into a bag. Examples of packaging bags include flat pouch-shaped packaging bags and self-standing packaging bags (standing pouches).

[0069] A flat pouch-shaped packaging bag may be, for example, a bag-shaped bag made by folding a single sheet of packaging film (a packaging film including a sealant film) in half so that the sealant films face each other, and then heat-sealing three sides, or a bag-shaped bag made by stacking two sheets of packaging film (a packaging film including a sealant film) on top of each other so that the sealant films face each other, and then heat-sealing four sides.

[0070] A self-standing packaging bag may be formed, for example, by stacking two packaging films (packaging films including a sealant film) with the sealant films facing each other, and inserting one packaging film (packaging film including a sealant film) between these films while folding it in half so that the sealant film faces outward, resulting in a total of three packaging films, which are then heat-sealed on all four sides to form a bag shape.

[0071] <Printed film manufacturing method> The method for producing a printed film of the present disclosure includes a step of forming a printing layer on a base film (hereinafter referred to as the "printing step"). The printing step includes a step (a) of printing colored inks on the base film to form colored regions, and a step (b) of printing transparent ink in areas on the base film other than the areas where the colored regions are to be formed to form dot-shaped transparent regions. In the printing step, the average area of ​​the dots constituting the transparent regions is 0.005 to 0.018 mm. 2 The printed layer is formed so that the area ratio of the transparent region to the region other than the colored region on the base film is 10 to 50%.

[0072] The above method makes it possible to obtain a printed film that is less susceptible to poor appearance due to air bubbles during laminate production and is less susceptible to blocking due to transparent regions. That is, the above method can also produce the printed film 1 of the above embodiment. The average area of ​​the dots and the area ratio of the transparent regions to the areas other than the colored regions on the base film can be changed by changing the printing conditions for the transparent ink, and can be adjusted to the ranges exemplified in the above embodiment. Furthermore, the thickness of the colored regions and the transparent regions can also be easily adjusted by adjusting the printing conditions.

[0073] Hereinafter, the method for producing a printed film according to the present disclosure will be described using the method for producing the above-described printed film 1 as an example.

[0074] (Step (a)) In step (a), colored inks are printed on a partial area of ​​the base film 11, and dried as necessary, to form a colored area 13 on the base film 11 (see FIG. 5).

[0075] The amount of color ink used and the type of color may be determined depending on the type of image to be expressed. The drying conditions of the color ink are not particularly limited and may be determined depending on the amount of solvent contained in the color ink.

[0076] (Step (b)) In step (b), transparent ink is printed in areas of the base film 11 other than the areas where the colored areas 13 are formed in step (a) to form dot-shaped transparent areas 14. This results in the printed film 1 shown in Figure 1.

[0077] The amount of transparent ink used may be set depending on the average area of ​​the dots constituting the transparent region, the height of the dots, the area ratio of the transparent region to the region other than the colored region on the base film, etc. The drying conditions for the transparent ink are not particularly limited, and may be set depending on the amount of solvent contained in the transparent ink.

[0078] In the above embodiment, the printing step may include a step (c1) of printing a transparent ink in an area where a step will be formed on the surface of the colored region. Here, the area where a step will be formed on the surface of the colored region is, for example, an area of ​​the colored region formed by printing the colored inks in step (a) that is thinner than the thickest point of the colored region by 0.5 μm or more. When there are multiple areas where a step will be formed on the surface of the colored region, in step (c1), the transparent ink is printed on some or all of the areas where a step will be formed on the surface of the colored region.

[0079] In the above embodiment, the above step may further include step (c2) of printing transparent ink on a region of the colored region where no step is formed on the surface. In step (c2), it is sufficient to print transparent ink on at least a part of the region of the colored region where no step is formed on the surface, and there may be regions where the transparent ink is not printed.

[0080] In the above embodiment, the order in which steps (a) and (b) are performed is not particularly limited. For example, steps (a) and (b) may be performed in parallel (almost simultaneously).

[0081] In the above embodiment, when one or more of step (c1) and step (c2) are performed in addition to step (b) after step (a), the order of performing these steps is not particularly limited. For example, two or more of step (b), step (c1), and step (c2) may be performed in parallel (almost simultaneously).

[0082] <Method of manufacturing laminate> The method for manufacturing a laminate of the present disclosure includes a step of preparing, as a first film, the printed film of the above embodiment or a printed film obtained by the method for manufacturing a printed film of the above embodiment (hereinafter referred to as "step (i)"), and a step of placing a second film on the printed layer of the first film via an adhesive layer (hereinafter referred to as "step (ii)").

[0083] Step (i) may be a step of preparing a pre-made printed film 1, or may be a step of producing the printed film 1 by the method for producing a printed film according to the above embodiment.

[0084] Step (ii) may be, for example, a step of laminating a first film and a second film together via an adhesive layer by dry lamination, thereby placing the second film on the printed layer of the first film. In the dry lamination method, an adhesive layer may be formed on the printed layer side of the first film, and then the second film may be placed on the adhesive layer (the side of the adhesive layer opposite the printed layer). Alternatively, an adhesive layer may be formed on the surface of the second film, and then the first film may be placed on the adhesive layer (the side of the adhesive layer opposite the second film) from the printed layer side.

[0085] The adhesive layer can be formed by applying an adhesive to the surface of the first film on the side of the printed layer or the surface of the second film, and drying it as necessary. As described above, either a solvent-based adhesive or a solventless adhesive may be used as the adhesive, but from the viewpoint of thinning the film, a solventless adhesive is preferably used. The method for applying the adhesive is not particularly limited, and may be, for example, a method such as roll coating. The amount of adhesive applied may be adjusted to obtain the desired thickness, and may be, for example, 0.5 to 5.0 g / m in terms of solid content. 2 The lamination conditions are not particularly limited and may be set depending on the type of adhesive used.

[0086] According to the above method, the laminate 100A shown in Fig. 3 can be obtained. Furthermore, although not shown, in the above method, after step (ii), a third film may be placed on the second film via an adhesive layer in the same manner as step (ii). According to this method, the laminate 100B shown in Fig. 4 can be obtained. [Example]

[0087] The present disclosure will be described in more detail below using examples and comparative examples, but the present disclosure is not limited to the following examples.

[0088] <Examples 1 to 4 and Comparative Examples 1 to 3> (Production of printing film) In all examples and comparative examples, a printed film that would become the first film was produced by forming a printed layer using ink (colored ink and clear ink, or colored ink only) on a 350 mm wide transparent vapor-deposited barrier film "GL-ARH" (manufactured by Toppan Printing Co., Ltd.).

[0089] In Examples 1 to 4 and Comparative Example 3, colored inks were gravure printed on the laminated surface of GL-ARH (the surface to which the second film is attached) to form colored regions, and then transparent ink was gravure printed in areas other than the areas where the colored regions were to be formed to form square lattice-shaped transparent regions composed of circular dots in a planar view. In Comparative Example 1, no transparent ink was used, and the printed layer of the printed film was formed by gravure printing only colored inks on the laminated surface of GL-ARH to form colored regions. In Comparative Example 2, the printed layer of the printed film was formed by gravure printing colored inks on the laminated surface of GL-ARH to form colored regions, and then gravure printing transparent ink over the entire area other than the areas where the colored regions were to be formed to form transparent regions.

[0090] The colored area, common to all examples and comparative examples, consisted of two uniformly spaced stripes of 50 mm width across the width of the film, each with a maximum thickness of 2 μm, spaced 100 mm apart and running continuously in the flow direction.

[0091] In Example 1, the average area of ​​the dots constituting the transparent region was set to 0.018 mm 2 The area ratio of the transparent region to the area other than the colored region on the base film was set to 27%, the average thickness of the transparent region (average dot height) was set to 2 μm, and the center-to-center distance between two adjacent dots was set to 0.25 mm.

[0092] In Example 2, the average area of ​​the dots constituting the transparent region was set to 0.018 mm 2The area ratio of the transparent region to the area other than the colored region on the base film was set to 43%, the average thickness of the transparent region (average dot height) was set to 2 μm, and the center-to-center distance between two adjacent dots was set to 0.20 mm.

[0093] In Example 3, the average area of ​​the dots constituting the transparent region was set to 0.005 mm 2 The area ratio of the transparent region to the area other than the colored region on the base film was set to 11%, the average thickness of the transparent region (average dot height) was set to 1.5 μm, and the center-to-center distance between two adjacent dots was set to 0.20 mm.

[0094] In Example 4, the average area of ​​the dots constituting the transparent region was set to 0.018 mm 2 The area ratio of the transparent region to the area other than the colored region on the base film was set to 27%, the average thickness of the transparent region (average dot height) was set to 1.5 μm, and the center-to-center distance between two adjacent dots was set to 0.25 mm.

[0095] In Comparative Example 2, the maximum height of the transparent region was set to 2 μm.

[0096] In Comparative Example 3, the average area of ​​the dots constituting the transparent region was 0.025 mm 2 The area ratio of the transparent region to the area other than the colored region on the base film was set to 39%, the average thickness of the transparent region (average dot height) was set to 2 μm, and the center-to-center distance between two adjacent dots was set to 0.25 mm.

[0097] The colored ink used was "Lio Alpha White" manufactured by Toyo Ink Co., Ltd., and the transparent ink used was a medium prepared by dissolving a mixed resin obtained by mixing 10 parts by mass of urethane resin and 2 parts by mass of vinyl chloride-vinyl acetate copolymer resin in a mixed solvent (methyl ethyl ketone / isopropyl alcohol / ethyl acetate).

[0098] (Preparation of laminate) Next, a laminate was produced by laminating the first film, a second film made of ONY film "ONMB-RT" (manufactured by Unitika Ltd.), and a third film made of PP sealant film "ZK207" (manufactured by Toray Advanced Film Co., Ltd.) in this order. The lamination was carried out so that the printed layer of the first film faced the second film. The solvent-free adhesive "TSN-4864A / TSN-4864B3" (manufactured by Toyo-Morton Co., Ltd., mass ratio 1:1) was used for the lamination. The solvent-free adhesive had a coating amount of 2 g / m 2 The film was coated with a roll coater so that the machine direction and width direction of each film were the same.

[0099] <Evaluation> The printed films obtained in the examples and comparative examples and the laminates produced using the printed films were evaluated for blocking resistance and appearance by the methods described below. The results are shown in Table 1.

[0100] (Blocking resistance) Ten 70 mm x 70 mm films were cut from a 100 mm wide region located between the colored regions (two strip-shaped patterns) of the first films produced in Examples 1 to 4 and Comparative Examples 1 to 3. The 10 cut films were then stacked with the printed layer facing the non-printed side (back) of the base film, sandwiched between 5 cm square iron plates from above and below to ensure no misalignment. A load of 200 kgf was applied using a constant-load compression tester, and the films were stored for 10 days at 50°C and 25% RH. After storage, a 15 mm wide laminate of the 10 films was cut, and the average peel strength between the films was measured. Measurements were performed according to the T-peel peel adhesion strength test method in accordance with JIS-K-6854-3:1999, except that the peel strength was calculated based on the peel strength within a minimum 30 mm range of the middle portion, excluding the first 5 mm immediately after the start of the test and the last 5 mm immediately before the end of the test. Using the measured values, the blocking resistance was evaluated according to the following index. ×: Average peel strength is 0.5N / 15mm or more △: Average peel strength is 0.1N / 15mm or more and less than 0.5N / 15mm Good: No sticking, average peel strength less than 0.1N / 15mm

[0101] (exterior) The laminates produced in Examples 1 to 4 and Comparative Examples 1 to 3 were aged in an environment of 40° C., and then the transparent regions were observed over a distance of 1 m in the flow direction and evaluated according to the following criteria. ×: Bubbles with a diameter of 1 mm or more are present ○: No bubbles corresponding to the above exist

[0102] [Table 1] [Explanation of symbols]

[0103] 1...printed film (first film), 2...second film, 3...third film, 11...base film, 12...printed layer, 13...colored region, 14...transparent region, 100A, 100B...laminate, S1, S2...adhesive layer.

Claims

1. A substrate film and a printing layer provided on the substrate film, When viewed from above the printed layer side of the base film, the printed layer includes a colored region containing a color pigment and a transparent region not containing a color pigment, the transparent area is made up of a plurality of dots, The average area of ​​the dots is 0.005 to 0.018 mm ２ and A printed film, wherein the area ratio of the transparent region to the area other than the colored region on the base film is 10 to 50%.

2. The printed film according to claim 1 , wherein the base film has a gas barrier layer.

3. a first film, an adhesive layer, and a second film in this order; The first film is the printed film according to claim 1 or 2, The adhesive layer is disposed on the printed layer of the first film.

4. The laminate according to claim 3 , wherein the adhesive layer is formed of a solventless adhesive.

5. A packaging film comprising the laminate of claim 3.

6. A packaging bag produced from the packaging film according to claim 5.

7. forming a printing layer on a substrate film; The process comprises: a step (a) of printing color inks on the base film to form colored areas; and (b) a step of printing a transparent ink on an area on the base film other than the area where the colored area is to be formed, to form a dot-shaped transparent area, In the step, the average area of ​​the dots constituting the transparent region is 0.005 to 0.018 mm ２ and forming the printed layer so that the area ratio of the transparent region to the area other than the colored region on the base film is 10 to 50%.

8. a step of preparing, as a first film, the printed film according to claim 1 or 2 or a printed film obtained by the manufacturing method according to claim 7; and placing a second film on the printed layer of the first film via an adhesive layer.

Images