Laminate and laminated tube

Abstract

To provide a laminate for laminated tubes capable of maintaining recognizability of laser prints, even when repeated to extract a content from a laminated tube and the laminated tube.SOLUTION: A laminate related to one embodiment is a laminate for a laminate tube, in which a first sealant layer, a substrate, a barrier layer, and a second sealant layer are stacked in this order. There are first and second regions based on the stacking direction of the first sealant layer, substrate, barrier layer, and second sealant layer. Between the substrate and the barrier layer in the first region, a printing layer and a first underlying layer are stacked in this order on the substrate. Between the substrate and the barrier layer in the second region, a dyeable ink layer that can be printed using laser light is stacked on the substrate, and the thickness of the dyeable ink layer is thicker than that of the printing layer. The laminate strength between the substrate and the barrier layer in the second region is 1.6 N / 15 mm or more.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a laminate and a laminate tube. [Background technology]

[0002] Laminated tubes that are constructed using a laminate with a color-developing ink layer are known (see Patent Documents 1 and 2). In such laminated tubes, the color-developing ink layer is laser-printed. For example, the date of manufacture and the like are printed on the color-developing ink layer using a laser beam. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6167803 [Patent Document 2] Patent No. 6167804 Summary of the Invention [Problem to be solved by the invention]

[0004] When the contents are repeatedly extracted from the laminate tube, the visibility of the laser-printed portion may decrease.

[0005] An object of one aspect of the present invention is to provide a laminate for a laminate tube and a laminate tube that are capable of maintaining the visibility of laser markings even when contents are repeatedly extracted from the laminate tube. [Means for solving the problem]

[0006] [1] A laminate according to one aspect of the present invention is a laminate for a laminate tube, comprising a first sealant layer, a substrate, a barrier layer and a second sealant layer laminated in this order, the laminate having a first region and a second region as viewed from a stacking direction of the first sealant layer, the substrate, the barrier layer and the second sealant layer, a printing layer and a first undercoat layer are laminated in this order on the substrate between the substrate and the barrier layer in the first region, a color-developing ink layer printable by laser light is laminated on the substrate between the substrate and the barrier layer in the second region, the color-developing ink layer is thicker than the printing layer, and a laminate strength between the substrate and the barrier layer in the second region is 1.6 N / 15 mm or more.

[0007] The laminate has a color-developing ink layer in the second region. Therefore, laser marking can be applied to the second region. The laminate strength between the substrate and the barrier layer in the second region is 1.6 N / 15 mm or more. Therefore, even if the contents are repeatedly extracted from a laminate tube manufactured using the laminate, peeling is unlikely to occur between the substrate and the barrier layer in the second region where laser marking is applied. As a result, the laminate tube manufactured using the laminate can maintain the visibility of the laser marking even when the laminate tube is used.

[0008] [2] In the laminate according to the above item [1], the color-developing ink layer may contain a copper molybdenum composite oxide or bismuth trioxide. The copper molybdenum composite oxide or bismuth trioxide functions as a color former.

[0009] [3] In the laminate according to the above [1] or [2], the first underlayer may be a white ink layer.

[0010] [4] In the laminate described in any one of [1] to [3] above, a second undercoat layer is laminated on the color-developing ink layer between the substrate and the barrier layer in the second region, and the thickness of the second undercoat layer may be thinner than the thickness of the first undercoat layer laminated on the printing layer.

[0011] [5] In the laminate according to the above [4], the second underlayer may be a white ink layer.

[0012] [6] A laminate tube according to another aspect of the present invention is a laminate tube using the laminate according to any one of the above [1] to [5]. Effect of the Invention

[0013] According to the present invention, it is possible to provide a laminate for a laminate tube and a laminate tube that are capable of maintaining the visibility of laser markings even if the contents are repeatedly extracted from the laminate tube. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic front view of a laminate tube according to one embodiment. [Diagram 2] FIG. 2 is a diagram for explaining an example of a layer structure of a laminate used in the body portion of the laminate tube shown in FIG. [Diagram 3] FIG. 3 is a diagram for explaining another example of the layer structure of the laminate. [Figure 4] FIG. 4 is a diagram for explaining an example of the configuration of the boundary portion between the first region and the second region. [Diagram 5] FIG. 5 is a table showing the results of Experimental Examples 1 to 6. [Figure 6] FIG. 6 is a table showing the results of Experimental Examples 7 to 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The same elements are given the same reference numerals. Duplicate explanations will be omitted. The dimensional ratios of the drawings do not necessarily match those in the description.

[0016] FIG. 1 is a schematic front view of a laminated tube 1 according to this embodiment. The laminated tube 1 is a type of tube, a container from which the fluid contents can be easily squeezed out and from which the exterior design can be printed as desired. The laminated tube 1 is widely used for storing semi-solid materials such as food, dentifrices, medicines, cosmetics, paints, adhesives, etc. The laminated tube 1 is superior to metal tubes and the like in terms of elasticity and shape recovery. The laminated tube 1 includes a body 2 and a head 3 joined to the body 2.

[0017] The head 3 has a cylindrical mouth 31 and a truncated cone-shaped shoulder 32 that connects the mouth 31 and the body 2. A topped cylindrical lid (not shown) is attached to the mouth 31. The mouth 31 may have an external thread (not shown) formed on its outer periphery that engages with the internal thread of the lid. The laminated tube 1 is configured to be sealed by attaching a lid to the mouth 31. The head 3 is made of a material that is highly compatible with the body 2 and does not affect the contents, and may be made of, for example, a thermoplastic resin.

[0018] The body 2 is composed of a laminate 10. To form the body 2 of the laminate tube 1, the laminate 10 is rolled into a cylindrical shape with one end overlapping the other end of the laminate 10. The one end and the other end of the laminate 10 rolled in this manner are heat-welded. Then, the shoulder 32 of the head 3, which is formed by compression molding or the like, and the laminate 10 of the body 2 are heat-welded and joined to each other, thereby forming the laminate tube 1.

[0019] The laminate 10 constituting the body 2 has a first region 2a and a second region 2b when viewed from the stacking direction of the layers of the laminate 10. The first region 2a is a region for displaying a desired pattern, symbol, etc. formed by a normal printing method (e.g., gravure printing). The second region 2b is a region (laser printed portion) for displaying the product name, date of manufacture, etc. as a laser printed image. In FIG. 1, the second region 2b is surrounded by the first region 2a, but the arrangement of the second region 2b is not limited to the form exemplified in FIG. 1.

[0020] Fig. 2 is a diagram for explaining an example of a layer structure of the laminate 10 used in the body 2 of the laminate tube 1 shown in Fig. 1. Specifically, Fig. 2 is a schematic diagram of a cross section including a boundary portion between the first region 2a and the second region 2b of the laminate 10.

[0021] The laminate 10 is a laminate film (or laminate sheet) for a laminate tube, which includes a first sealant layer 11, a substrate 12, an intermediate layer 13, a barrier layer 14 and a second sealant layer 15.

[0022] The first sealant layer 11 and the second sealant layer 15 are layers that are heat-sealed to each other when constructing the body portion 2. The first sealant layer 11 is the outermost layer in the body portion 2. The second sealant layer 15 is the innermost layer in the body portion 2.

[0023] An example of the material of the first sealant layer 11 and the second sealant layer 15 is polyolefin. Examples of the polyolefin include low density polyethylene (LDPE), medium density polyethylene, high density polyethylene, polypropylene, and copolymerized polyolefins obtained by copolymerizing two or more kinds of olefin monomers. An example of such a copolymerized polyolefin is linear low density polyethylene (LLDPE) obtained by copolymerizing ethylene monomer and butene monomer. The material of the first sealant layer 11 and the second sealant layer 15 may be a modified polyolefin resin obtained by modifying these polyolefins.

[0024] Each of the first sealant layer 11 and the second sealant layer 15 may be a single layer formed of polyolefin, or may have a multi-layer structure. For example, an antistatic agent may be added to the first sealant layer 11.

[0025] An example of the thickness of the first sealant layer 11 is 20 μm or more and 150 μm or less. An example of the thickness of the second sealant layer 15 is 20 μm or more and 150 μm or less.

[0026] The substrate 12 has a function of providing the laminated tube 1 with basic mechanical properties such as maintaining the shape of the laminated tube 1 and restoring ability, and a function of acting as a protective layer for the printed layer 131, the color-developing ink layer, etc. The substrate 12 is configured so that the patterns, characters, etc. shown in the printed layer 131 and the color-developing ink layer can be visually recognized. The substrate 12 may be a resin film.

[0027] Examples of materials for the substrate 12 include polyester, polyolefin, polyamide, polyimide, etc. Examples of polyolefins include polyethylene and polypropylene. Examples of polyesters include polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, etc. Examples of polyamides include nylon-6 and nylon-66. The substrate 12 may be, for example, a polyethylene terephthalate (PET) film. The substrate 12 may be a uniaxially or biaxially stretched film. An example of the thickness of the substrate 12 is 9 μm or more and 25 μm or less.

[0028] The substrate 12 and the first sealant layer 11 are laminated together by, for example, extrusion lamination. In this case, as shown in Fig. 2, the substrate 12 and the first sealant layer 11 are laminated together via an extruded resin layer 16. Examples of materials for the extruded resin layer 16 include LDPE, LLDPE, and the like.

[0029] In the substrate 12, an anchor coat (AC) agent layer 17 may be formed on a first surface 12a located on the first sealant layer 11 side.

[0030] The intermediate layer 13 is provided on the second surface 12b of the substrate 12. The second surface 12b is the surface opposite to the first surface 12a.

[0031] A portion of the intermediate layer 13 corresponding to the first region 2a has a printed layer 131 and an underlayer (first underlayer) 132. The printed layer 131 and the underlayer 132 are laminated on the second surface 12b in this order. Therefore, the portion of the second surface 12b located in the first region 2a has a laminated structure of the printed layer 131 and the underlayer 132. The thickness of the laminated structure of the printed layer 131 and the underlayer 132 may be referred to as the thickness of the intermediate layer 13.

[0032] The printed layer 131 is a layer on which a desired pattern, symbol, etc. is printed. The printed layer 131 is formed by a known printing method such as gravure printing, offset printing, flexographic printing, silk printing, etc., using color inks corresponding to the pattern to be printed. An example of the thickness of the printed layer 131 is 0.1 μm or more and 7 μm or less. An example of the application amount of the color ink constituting the printed layer 131 is 2 g / m. 2 Above 5g / m 2 The coating amount after drying is 1g / m 2 More than 2.5g / m 2 The following is the result.

[0033] The base layer 132 is formed of a known white ink as a printing base for improving the visibility of a pattern or the like displayed by the printed layer 131. The white ink layer (or white ink) as the base layer 132 contains a binder resin and a white ink pigment.

[0034] Examples of binder resins include urethane, polyester, acrylic, and cellulose-based resins. Examples of white ink pigments include titanium oxide and zinc oxide. Titanium oxide is an effective white ink pigment in terms of cost and availability. An example of the amount of white ink pigment added is 10% by mass or more and 60% by mass or less.

[0035] An example of the thickness of the undercoat layer 132 is 0.1 μm or more and 7 μm or less. An example of the coating amount of the white ink constituting the undercoat layer 132 is 2 g / m 2 Above 5g / m 2 The coating amount after drying is 1g / m 2 More than 2.5g / m 2 The following is the result.

[0036] As described above, the printed layer 131 is a layer on which a pattern or the like is printed. Therefore, the printed layer 131 is formed according to the shape of the pattern, symbol, etc. Therefore, the part of the intermediate layer 13 in the first region 2a on which a pattern or the like is not printed (part between the pattern, symbol, etc.) may be filled with the base layer 132.

[0037] A portion of the intermediate layer 13 that corresponds to the second region 2b has a color-developing ink layer 133. Therefore, the color-developing ink layer 133 is formed on the portion of the second surface 12b that is located in the second region 2b.

[0038] The color-developing ink layer 133 is a layer that can be laser-printed by being irradiated with a laser beam. In other words, the color-developing ink layer 133 is a layer on which a laser-printed image is displayed. The laser-printed image includes information such as the product name and the date of manufacture.

[0039] The color-developing ink layer 133 is configured to develop color when irradiated with a laser beam. The color-developing ink layer 133 (or color-developing ink) contains a binder resin and a color-developing material. Examples of the binder resin are the same as those of the underlayer 132.

[0040] Examples of the coloring material include molybdenum-containing complex oxides and bismuth-based compounds. Molybdenum-containing complex oxides are known as coloring materials that develop color with low-power laser light. From the viewpoint of developing color with low-power laser light, molybdenum-containing complex oxides are effective as coloring materials for the coloring ink layer 133. Examples of the molybdenum-containing complex oxides include copper molybdenum complex oxides and tin molybdenum complex oxides. As the molybdenum-containing complex oxides, copper molybdenum complex oxides are effective in terms of cost and availability. Examples of the bismuth-based compounds include bismuth trioxide, bismuth nitrate-based compounds (e.g., bismuth nitrate, bismuth oxynitrate, etc.), bismuth halide-based compounds (e.g., bismuth chloride), bismuth oxyhydrochloride, bismuth sulfate, bismuth acetate, bismuth citrate, bismuth hydroxide, bismuth titanate, etc. As the bismuth-based compound, bismuth trioxide is effective in terms of cost and availability.

[0041] The color-developing ink layer 133 may contain an inorganic compound for improving color development efficiency. Examples of such inorganic compounds include titanium oxide, zinc oxide, etc. Titanium oxide is an effective inorganic compound for improving color development efficiency in terms of cost and availability.

[0042] In the color ink layer 133 (or color ink), the content of the color material is 0.001% by mass or more and 20% by mass or less. When the color ink layer 133 contains an inorganic compound for improving coloring efficiency, the content thereof is 10% by mass or more and 40% by mass or less.

[0043] The thickness of the color-developing ink layer 133 is thicker than the thickness of the printing layer 131. The color-developing ink layer 133 is equal to or thinner than the intermediate layer 13. An example of the coating amount of the color-developing ink constituting the color-developing ink layer 133 is 2 g / m 2 Above 9g / m 2 The coating amount after drying is 1g / m 2 Above 4.5g / m 2 The following is the result.

[0044] The barrier layer 14 is laminated on the intermediate layer 13. An example of the thickness of the barrier layer 14 is 6 μm or more and 30 μm or less. An example of the barrier layer 14 is a metal foil. An example of the metal foil is an aluminum foil (hereinafter referred to as "AL foil"). In addition to AL foil, the metal foil may be copper foil or the like. The barrier layer 14 may be an inorganic compound layer provided on a base film by a vapor deposition method. Examples of the material of the base film may be the same as the examples of the base material 12. Examples of the material of the inorganic compound layer are alumina, silicon oxide, and the like.

[0045] The substrate 12 on which the intermediate layer 13 is formed and the barrier layer 14 may be joined via an adhesive layer 18a. The adhesive constituting the adhesive layer 18a is not particularly limited in type, but may be appropriately selected taking into consideration adhesion to the film and safety when the laminated tube 1 is used for food or the like. For example, a two-component curing polyurethane adhesive can be used as the adhesive constituting the adhesive layer 18a. The method of lamination using the adhesive layer 18a is not particularly limited in type either, but for example, a dry lamination method is used.

[0046] The barrier layer 14 and the second sealant layer 15 may also be bonded via an adhesive layer 18b. Examples of the adhesive constituting the adhesive layer 18b are the same as those for the adhesive layer 18a. The method of bonding using the adhesive layer 18b is not particularly limited, and a dry lamination method, for example, is used.

[0047] FIG. 3 is a diagram for explaining another example of the layer structure of the laminate 10 used in the body portion 2 of the laminate tube 1 shown in FIG.

[0048] As shown in FIG. 3, an underlayer (second underlayer) 134 may be laminated on the color ink layer 133. In this case, the thickness of the laminated structure of the color ink layer 133 and the underlayer 134 is approximately the same as the thickness of the intermediate layer 13. An example of the composition of the underlayer 134 is the same as that of the underlayer 132. The thickness of the underlayer 134 is thinner than the thickness of the underlayer 132 located on the printing layer 131. An example of the thickness of the underlayer 134 is 0.05 μm or more and 3.5 μm or less. An example of the application amount of the white ink constituting the underlayer 134 is 1 g / m. 2 More than 3g / m 2 An example of the coating amount after drying is 0.5 g / m 2 More than 1.5g / m 2 The following is the result.

[0049] 2, in the boundary portion between the first region 2a and the second region 2b in the intermediate layer 13, for example, a color-developing ink layer 133 may overlap the printed layer 131 and the base layer 132 as shown typically in Fig. 4. The length (width) of the region 135 where the color-developing ink layer 133 overlaps the printed layer 131 and the base layer 132 may be 0.1 mm or more and 1 mm or less.

[0050] Laser marking on the color-developing ink layer 133 is performed by selectively irradiating the color-developing ink layer 133 with laser light from the substrate 12 side. For example, YVO4 laser light (wavelength 1064 nm), YAG laser light (wavelength 1064 nm), etc. are used for laser marking. Pulsed light is used as the laser light. Examples of the conditions for laser irradiation are as follows. During laser marking, the laser light is not irradiated to any area other than the second region 2b.

[0051] Laser power: 1W or more and 10W or less Scan speed: 1000mm 2 / sec or more and 10000mm 2 / sec Repetition frequency: 10kHz or more and 100kHz or less

[0052] The laminate strength between the substrate 12 and the barrier layer 14 in the second region 2b of the laminate 10 is 1.6 N / 15 mm or more. The laminate strength may be 15 N / 15 mm or less. The laminate strength may be 2.0 N / 15 mm or more and 12 N / 15 mm or less.

[0053] The laminate strength between the substrate 12 and the barrier layer 14 in the second region 2b is measured, for example, as follows. <Method of measuring laminate strength> A rectangular test piece is cut out from the second region 2b of the laminate 10. The length of the short side (width direction) of the test piece is 15 mm. A T-peel test is performed between the substrate 12 and the barrier layer 14 of the test piece at a peel speed of 300 mm / min in accordance with JIS K 6854 under conditions of 20°C and 30% RH. The peel strength thus obtained is defined as the laminate strength.

[0054] As described above, in the laminate 10, the laminate strength between the substrate 12 and the barrier layer 14 in the second region 2b, which is the laser-printed portion, is 1.6 N / 15 mm or more. Therefore, when the laminate tube 1 is formed using the laminate 10, peeling between the substrate 12 and the barrier layer 14 (hereinafter also referred to as "lamination lifting") is unlikely to occur even if squeezing (extraction) is performed multiple times to remove the contents from the laminate tube 1. As a result, good visibility of the laser-printed image can be stably ensured even if the above-mentioned squeezing is performed multiple times.

[0055] This point will be described in more detail with reference to experimental examples. In the following experimental examples, for the sake of convenience, elements corresponding to those in the description of the laminate 10 above are given the same reference numerals, and duplicated descriptions will be omitted, even in cases where the experimental examples are for comparison purposes.

[0056] [Experimental Examples 1-6] In Experimental Examples 1 to 6, laminate films (hereinafter referred to as "laminated films F") were prepared that had the layer structure A shown in Table 1 but had different coating amounts of the color ink layer and the white ink layer. [Table 1]

[0057] The laminate film F having the layer structure A is a model of the second region 2b in the laminate 10.

[0058] The first LLDPE film shown in Table 1 corresponds to the first sealant layer 11 shown in FIG. 2. For the first LLDPE film, "L140R-1" manufactured by Aicello Co., Ltd. was used. The thickness of the first LLDPE film was 80 μm. An antistatic agent was added to the first LLDPE film.

[0059] The PET film shown in Table 1 corresponds to the substrate 12 shown in Fig. 2. The PET film used was "E5102" manufactured by Toyobo Co., Ltd. The thickness of the PET film was (12 µm).

[0060] The color ink layer shown in Table 1 corresponds to the color ink layer 133 shown in Fig. 2. The color ink constituting the color ink layer 133 was "Elbima Z117" manufactured by Toyo Ink Co., Ltd. "Elbima Z117" contained copper molybdenum composite oxide as a color former.

[0061] The white ink layer shown in Table 1 corresponds to the undercoat layer 132 shown in Fig. 2. The white ink constituting the white ink layer was "Bellcolor HS165" manufactured by Sakata Inx Corporation. "Bellcolor HS165" contained titanium oxide as a white ink pigment.

[0062] The Al foil shown in Table 1 corresponds to the barrier layer 14 shown in Figure 2. The thickness of the Al foil was 15 µm.

[0063] The second LLDPE film shown in Table 1 corresponds to the second sealant layer 15 shown in Figure 2. For the second LLDPE film, "SE620A" manufactured by Tamapoly Co., Ltd. was used. The thickness of the second LLDPE film was 130 μm.

[0064] The PET film and the first LLDPE film were laminated by extrusion lamination after the AC agent was applied to the surface of the PET film facing the first LLDPE film. Therefore, as shown in Table 1, an AC agent layer and an extruded LDPE layer were provided between the PET film and the first LLDPE film.

[0065] The AC agent layer shown in Table 1 corresponds to the AC agent layer 17 shown in FIG. 2. The AC agent constituting the AC agent layer was "A3210 / A3070" manufactured by Mitsui Chemicals, Inc. The coating amount of the AC agent layer was 1 g / m 2 It was.

[0066] The extruded LDPE layer shown in Table 1 corresponds to the extruded resin layer 16 shown in Figure 2. The LDPE constituting the extruded LDPE layer was "LC600A" manufactured by Japan Polyethylene Co., Ltd. The thickness of the extruded LDPE layer was 30 μm.

[0067] The PET film on which the color-developing ink layer 133 and the white ink layer were laminated by applying the color-developing ink and the white ink, the AL foil, and the second LLDPE film were laminated by dry lamination. Therefore, a first adhesive layer and a second adhesive layer were provided between the PET film on which the color-developing ink layer and the white ink layer were laminated and the AL foil, and between the AL foil and the second LLDPE film, as shown in Table 1. The first adhesive layer and the second adhesive layer correspond to the adhesive layer 18a and the adhesive layer 18b shown in FIG. 2. A polyurethane adhesive ("Takelac A626 / A50" manufactured by Mitsui Chemicals, Inc.) was used as the adhesive constituting the first adhesive layer and the second adhesive layer. The amount of adhesive applied was 3.0 g / m 2 It was.

[0068] Using the above laminate film F, the lamination strength between the PET film and the AL foil was measured as follows.

[0069] <Laminate strength measurement test> A rectangular test piece was cut out from the laminated film F. The length of the test piece in the short side direction was 15 mm, and the length in the long side direction was 100 mm. A T-shaped peel test was performed between the PET film and the AL foil on the test piece at a peel speed of 300 mm / min in accordance with JIS K 6854 under conditions of 20°C and 30% RH. The peel strength thus obtained was used as the laminate strength. The tensile tester used for the tensile test was the "RTC-1310A" manufactured by A&D Co., Ltd.

[0070] In addition to the case where one of the color ink and the white ink is not applied, the amount of the color ink and the white ink applied is 2.0 g / m 2 , 3.0g / m 2 and 4.0 g / m 2 In each of the three settings, a laminate film F was produced and the above-mentioned laminate strength measurement test was carried out.

[0071] (1) Experimental Example 1 In Experimental Example 1, the amount of color ink applied was 2.0 g / m 2 The amount of white ink applied was 3.0 g / m 2 A laminate film F was produced as the laminate film F and a laminate strength measurement test was carried out.

[0072] (2) Experimental Example 2 In Experimental Example 2, the amount of color ink applied was 2.0 g / m 2 The amount of white ink applied was 2.0 g / m 2 A laminate film F was produced as the laminate film F and a laminate strength measurement test was carried out.

[0073] (3) Experimental Example 3 In Experimental Example 3, the amount of color ink applied was 2.0 g / m 2 The amount of white ink applied was 0.0 g / m 2 The laminate strength measurement test was carried out on the laminate film F with the white ink coating amount of 0.0 g / m2. 2 Therefore, white ink was not applied in Experimental Example 3. Therefore, the laminate film F produced in Experimental Example 3 did not have a white ink layer, and the color-developing ink layer was in contact with the first adhesive layer.

[0074] (4) Experimental Example 4 In Experimental Example 4, the amount of color ink applied was 3.0 g / m 2 The amount of white ink applied was 0.0 g / m 2 The laminate strength measurement test was carried out on the laminate film F with the white ink coating amount of 0.0 g / m2. 2 Therefore, the laminate film F produced in Experimental Example 4, like the case of Experimental Example 3, did not have a white ink layer, and the color ink layer was in contact with the first adhesive layer.

[0075] (5) Experimental Example 5 In Experimental Example 5, the amount of color ink applied was 0.0 g / m 2 The amount of white ink applied was 4.0 g / m 2 The laminate strength measurement test was carried out on the laminate film F with the coating amount of color-developing ink of 0.0 g / m2. 2 Therefore, no color-developing ink was applied in Experimental Example 5. Therefore, the laminate film F produced in Experimental Example 5 did not have a color-developing ink layer, and the white ink layer was laminated directly on the PET film.

[0076] (6) Experimental Example 6 In Experimental Example 6, the coating amount of color ink was 2.0 g / m 2 The white ink coating amount is 42.0 g / m 2 A laminate film F was produced as the laminate film F and a laminate strength measurement test was carried out.

[0077] The results of the laminate strength measurement tests in Experimental Examples 1 to 6 are shown in FIG.

[0078] From the results shown in Figure 5, it can be seen that the laminate strength increases by increasing the amount of colored ink applied, and that the laminate strength increases by decreasing the amount of white ink applied. From the results shown in Figure 5, it can also be seen that, when the amount of colored ink is the same, the laminate strength increases by decreasing the amount of white ink applied, or, when the amount of white ink is the same, by increasing the amount of colored ink applied. In other words, from the results shown in Figure 5, it can be seen that the laminate strength increases when the amount of colored ink applied is relatively large.

[0079] [Experimental Examples 7-12] In Experimental Examples 7 to 12, the laminated films F produced in Experimental Examples 1 to 6 were laser-printed, and then bending tests were carried out.

[0080] Laser marking was performed by irradiating a laser beam from the first LLDPE film side in layer configuration A shown in Table 1. The laser conditions for laser marking were as follows. The laser marking conditions in Experimental Examples 7 to 12 were the same. (Laser conditions) Laser device: Keyence Corporation's "MD-V9900(A)" (YVO4 laser) Laser power: 3.3W Scan speed: 2500mm 2 / sec Q-switch frequency (repetition rate): 40kHz

[0081] The bending test was carried out as follows. (Bending test) In accordance with ASTM F392, a bending test was conducted on the laser-printed laminated film F using a "Gelbo Flex Tester" manufactured by Tester Sangyo Co., Ltd. The appearance of the laminated film F after the bending test was checked by five people.

[0082] When four or more people judged the visibility of the laser marking to be good, it was given a rating of "A+", when two or three people judged the visibility of the laser marking to be good, it was given a rating of "A", and when it did not fall under either the rating of "A+" or the rating of "A", it was given a rating of "B".

[0083] The results of the bending strength test in Experimental Examples 7 to 12 are shown in Figure 6. In Figure 6, Experimental Examples 1 to 6 are written in parentheses around Experimental Examples 7 to 12 to show the correspondence between the laminate film F used in Experimental Examples 7 to 12 and the laminate film F produced in Experimental Examples 1 to 6. For example, "Experimental Example 7 (Experimental Example 1)" indicates that Experimental Example 7 is an experimental example carried out using the laminate film F produced in Experimental Example 1. Figure 6 also shows the lamination strength of the laminate film F measured in Experimental Examples 1 to 6.

[0084] As shown in FIG. 6, in Experimental Example 11, the visibility of the laser marking was evaluated as "B" when the number of bending times was 25 or more, and in Experimental Example 12, the visibility of the laser marking was evaluated as "B" when the number of bending times was 30 or more. In contrast, in Experimental Examples 7 to 10, the visibility of the laser marking was evaluated as "A" or "A+" even when the number of bending times was 30 or more. That is, in Experimental Examples 7 to 10, even when the number of bending times was 30 or more, good visibility of the laser marking was maintained without the influence of lamination lifting. Therefore, it was verified that if the lamination strength between the PET film and the AL foil is 1.6 N / 15 mm or more, good visibility of the laser marking can be maintained even when the laminated film F on which laser printing has been performed is bent 30 or more times.

[0085] From the results of the above experimental examples, it can be seen that if the laminate strength between the substrate 12 and the barrier layer 14 is 1.6 N / 15 mm or more, the effect of lamination lifting can be reduced even if the contents are repeatedly extracted multiple times from the laminated tube 1 constructed using the laminate 10 and having laser printing applied thereto, and as a result, good visibility of the laser printing can be maintained.

[0086] Although the embodiment and experimental examples of the present invention have been described above, the present invention is not limited to the above embodiment and experimental examples. The present invention is intended to include all modifications within the scope indicated by the claims and the meaning and scope equivalent to the claims. [Explanation of symbols]

[0087] 1... laminated tube, 2a... first region, 2b... second region, 10... laminate, 11... first sealant layer, 12... substrate, 14... barrier layer, 15... second sealant layer, 131... printed layer, 132... base layer (first base layer), 133... color-developing ink layer, 134... base layer (second base layer).

Claims

1. A laminate for a laminate tube, comprising a first sealant layer, a substrate, a barrier layer, and a second sealant layer laminated in this order, a first region and a second region when viewed from a lamination direction of a first sealant layer, the substrate, the barrier layer, and the second sealant layer, a printing layer and a first base layer are laminated in this order on the substrate between the substrate and the barrier layer in the first region, a color-developing ink layer that can be printed by a laser beam is laminated on the substrate between the substrate and the barrier layer in the second region; The thickness of the color-developing ink layer is greater than the thickness of the printing layer, The laminate strength between the substrate and the barrier layer in the second region is 1.6 N / 15 mm or more. Laminate.

2. The color-developing ink layer contains copper-molybdenum composite oxide or bismuth trioxide. The laminate according to claim 1 .

3. The first undercoat layer is a white ink layer. The laminate according to claim 1 .

4. a second undercoat layer is laminated on the color-developing ink layer between the substrate and the barrier layer in the second region; The thickness of the second undercoat layer is thinner than the thickness of the first undercoat layer laminated on the printing layer. The laminate according to claim 1 .

5. The second undercoat layer is a white ink layer. The laminate according to claim 4.

6. A laminate tube using the laminate according to any one of claims 1 to 5.

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