WO2024252968A1 - Layered body for laminate tube container - Google Patents

Abstract

As shown in FIG. 1(a), in a layered body 100 for a laminate tube container according to the present invention, when portions of sealant layers 110, 160 are superposed and then subjected to heat sealing to form a tubular laminate tube container, print layers 130 include a bright print layer 132 that is to be present over substantially the entirety of a side seam portion, the bright print layer 132 contains a bright pigment, a polyurethane acrylate, and a photopolymerization initiator, and does not contain a polyisocyanate, the outer sealant layer 110 and the inner sealant layer 160 are composed of a polyethylene-based resin, and at least one of the print layers is in direct contact with a printed layer of a base material layer 140.

Description

Laminated tube container laminate

The present invention relates to a laminate for laminated tube containers.

Conventionally, laminated tube containers have been manufactured in various ways. For example, a laminated sheet is manufactured, and the outermost and innermost layers at both ends are heat-sealed to form a cylindrical body. Then, a head consisting of a mouth and a shoulder is formed at one opening of the cylindrical body, and a cap is screwed onto the mouth to manufacture a laminated tube container. The location where the outermost and innermost layers are heat-sealed is sometimes called the side seam. The laminated tube container manufactured in this way can be filled with semi-fluid contents such as toothpaste from the open end of the cylindrical body, and the open end is hermetically sealed to form a bottom seal, to form a tube-shaped packaged product.

It is also known to incorporate a substrate and a printed layer into the body of a laminated tube container in order to improve the distinctiveness or appearance of the laminated tube container.

Patent Document 1 discloses a laminated sheet for forming the body of a laminated tube container, which is formed into a cylindrical body so that the innermost layer of the laminated film becomes the inner peripheral layer of the body of the laminated tube container. This laminated film is made up of, from the innermost layer, a heat-sealable film (I), a barrier layer, a milky white polyethylene resin film, a transparent substrate film with a colored printing ink layer formed on one side, and a transparent heat-sealable film (II), which are laminated via adhesive layers.

For laminated tube containers with a printing layer, it has been proposed to print the entire surface, including the side seam portion (also called "full print printing"). For example, Patent Document 2 discloses a laminate for tubes that includes a laminated surface layer, an adhesive layer, a UV ink layer, and a base laminate. The surface layer includes polyolefin. The adhesive layer is formed of a two-component adhesive of a polyol having an ester portion and a polyisocyanate. The surface of the base laminate that comes into contact with the UV ink layer is formed of polyolefin. The UV ink layer is disposed in a location that corresponds to the seal portion on the surface of the base laminate.

Furthermore, with regard to printing to provide plastic containers with a luxurious feel, it is known to use a glittering print layer obtained from pearl ink or the like. Patent Document 3 discloses a laminate for a laminate tube having a surface layer, a glittering print laminate, and a substrate in that order. The glittering print laminate has multiple glittering print layers laminated on top of each other. Each of the multiple glittering print layers contains an ultraviolet-curable resin and an inorganic glittering pigment. The ultraviolet-curable resin contains an aliphatic polyurethane acrylate and a photopolymerization initiator that has less than three benzene rings and does not have an amino group.

JP 2013-223934 A International Publication No. 2014/178403 JP 2021-178446 A

The present invention provides a new laminate for laminated tube containers that reduces manufacturing costs and does not impair laminate strength even when a glossy printed layer is provided on the side seam.

As a result of intensive research, the present inventors have found that the above problems can be solved by the following means, and have completed the present invention. That is, the present invention is as follows:
<Aspect 1> The laminate is composed of an outer sealant layer, an outer adhesive layer, one or more printed layers, a substrate layer, an inner adhesive layer, and an inner sealant layer in this order,
a part of the outer sealant layer and a part of the inner sealant layer are overlapped and heat-sealed to form a side seam portion to form a cylindrical laminated tube container, the printed layer including a glittering printed layer that is present over substantially the entire side seam portion,
The photoluminescent print layer is made of an ultraviolet-curable flexographic photoluminescent ink, and the ultraviolet-curable flexographic photoluminescent ink contains a photoluminescent pigment, a polyurethane acrylate, and a photopolymerization initiator, but does not contain a polyisocyanate;
the photopolymerization initiator has less than three benzene rings and has no amino group;
The outer sealant layer and the inner sealant layer are made of a polyethylene resin,
The base layer has a printable layer, and at least one of the printable layers is in direct contact with the printable layer.
Laminated body for laminated tube containers.
<Mode 2> A laminate for a laminated tube container described in Mode 1, wherein the printed layer further has an undercoat printed layer in direct contact with the base layer, and a portion of the outer sealant layer and a portion of the inner sealant layer are overlapped and heat sealed to form a side seam portion, so that when the laminated tube container is made into a cylindrical laminated tube container, the undercoat printed layer is present over almost the entire side seam portion.
<Embodiment 3> The laminate for a laminate tube container according to embodiment 2, wherein the undercoat printing layer contains a polyisocyanate.
<Embodiment 4> A laminate for laminated tube containers according to embodiment 2 or 3, wherein the glossy printed layer is in direct contact with the base printed layer.
Aspect 5: The laminate for a laminate tube container according to any one of aspects 1 to 4, wherein the content of the glittering pigment is 1% by mass or more and 30% by mass or less relative to the mass of the ultraviolet curable flexographic glittering ink.
Aspect 6: The laminate for laminate tube containers according to any one of aspects 1 to 5, wherein the content of the photopolymerization initiator is 1% by mass or more and 30% by mass or less relative to the mass of the ultraviolet curable flexographic photoluminescent ink.
<Embodiment 7> A laminate for laminated tube containers according to any one of embodiments 1 to 6, wherein the printable layer is made of a polyethylene-based resin.
<Embodiment 8> A laminate for laminated tube containers according to any one of embodiments 1 to 7, wherein the outer adhesive layer is a two-component curing dry lamination adhesive.
<Aspect 9> A laminate for a laminate tube container according to any one of aspects 1 to 8,
A part of the outer sealant layer and a part of the inner sealant layer are overlapped and heat-sealed to form a side seam portion, thereby forming the laminated tube container laminate into a cylindrical shape.
Laminated tube container.

The present invention provides a novel laminate for laminated tube containers that reduces manufacturing costs while not compromising laminate strength even when a glossy printed layer is provided on the side seam.

Fig. 1(a) is a side cross-sectional view of one embodiment of the laminate for a laminate tube container of the present invention, and Fig. 1(b) is a side cross-sectional view of another embodiment of the laminate for a laminate tube container of the present invention. Fig. 2(a) is a schematic side view of one embodiment of the laminated tube container of the present invention. Fig. 2(b) is a schematic cross-sectional view of one embodiment of the laminated tube container of the present invention taken along line IIb-IIb in Fig. 2(a). Fig. 2(c) is an enlarged view of the part surrounded by line IIc in Fig. 2(b).

<Laminate for Laminated Tube Containers>
As shown in FIG. 1( a ), the laminated tube container laminate 100 of the present invention has the following features:
The laminate includes an outer sealant layer 110, an outer adhesive layer 120, one or more printed layers 130, a substrate layer 140, an inner adhesive layer 150, and an inner sealant layer 160, in this order.
When a part of the outer sealant layer 110 and a part of the inner sealant layer 160 are overlapped and heat sealed to form a side seam portion to form a cylindrical laminated tube container, the printed layer 130 includes a glittering printed layer 132 that is present over substantially the entire side seam portion,
The photoluminescent print layer 132 is made of an ultraviolet-curing flexographic photoluminescent ink, and the ultraviolet-curing flexographic photoluminescent ink contains a photoluminescent pigment, a polyurethane acrylate, and a photopolymerization initiator, but does not contain a polyisocyanate;
the photopolymerization initiator has less than three benzene rings and has no amino group;
The outer sealant layer 110 and the inner sealant layer 160 are made of a polyethylene resin,
The base layer 140 has a printable layer, and at least one of the printable layers is in direct contact with the printable layer.

The glittering printing layer contains a glittering application material that is a relatively large, flat-shaped application material. In conventional laminated tubes having such a glittering printing layer, when the glittering printing layer is laminated so as to be contained in the side seam portion, it was thought that it was necessary to contain polyisocyanate in the glittering printing layer in order not to impair the laminate strength. On the other hand, when polyisocyanate is contained in the ink that constitutes the glittering printing layer, its reactivity makes it difficult to store the glittering printing ink. Because the glittering application material is relatively expensive, the difficulty in storing the glittering printing ink is a major problem in terms of cost.

In response to this, the inventors have discovered that a combination of polyurethane acrylate and a photopolymerization initiator can produce a glossy printed layer that does not contain polyisocyanate and does not impair laminate strength even when laminated over the entire substrate layer.

As shown in FIG. 1(b), the printing layer 130 may further include an undercoat printing layer 134 and another printing layer 136.

The following describes each component of the present invention.

<Outer sealant layer and inner sealant layer>
The outer sealant layer and the inner sealant layer are made of a polyethylene resin.

In this specification, a polyethylene resin is a resin that contains more than 50 mol%, 60 mol% or more, 70 mol% or more, or 80 mol% or more of repeating ethylene groups in the polymer main chain, and is selected from the group consisting of, for example, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), and derivatives thereof, and mixtures thereof.

The thickness of the outer sealant layer and the inner sealant layer is not particularly limited, and may be, for example, 50 μm or more and 200 μm or less. This thickness may be 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 85 μm or more, 90 μm or more, or 95 μm or more, and may be 200 μm or less, 190 μm or less, 180 μm or less, 170 μm or less, 160 μm or less, 150 μm or less, 140 μm or less, 130 μm or less, 125 μm or less, 120 μm or less, 115 μm or less, 110 μm or less, or 105 μm or less. The outer sealant layer and the inner sealant layer may be the same as each other or different.

<Outer adhesive layer>
The outer adhesive layer is a layer that is between the outer sealant layer and the printed layer or layers, thereby adhering them to one another.

As the adhesive layer, for example, a dry lamination adhesive, a hot melt adhesive, a water-soluble adhesive, an emulsion adhesive, a non-solvent lamination adhesive, and a thermoplastic resin for extrusion lamination can be used. Among them, it is preferable to use a dry lamination adhesive, in particular a two-component curing dry lamination adhesive.

<Printed layer>
The printing layer may be one or more printing layers, at least one of which is in direct contact with the printable layer of the base layer.

When a part of the outer sealant layer and a part of the inner sealant layer are overlapped and heat sealed to form a side seam portion to produce a cylindrical laminated tube container, these printed layers include a photoluminescent printed layer that is present over substantially the entire side seam portion.

In this context, "substantially the entire side seam portion" means that it occupies 90% or more, 95% or more, 97% or more, 98% or more, or 99% or more of the area of the side seam portion.

When a part of the outer sealant layer and a part of the inner sealant layer are overlapped and heat sealed to form a side seam portion to form a cylindrical laminated tube container, the printed layer may have a base printed layer that is present over substantially the entire side seam portion. In this case, the base printed layer is in direct contact with the printed layer.

(Glossy Printing Layer)
The photoluminescent print layer is a layer composed of an ultraviolet-curable flexographic photoluminescent ink. The ultraviolet-curable flexographic photoluminescent ink contains a photoluminescent pigment, a polyurethane acrylate, and a photopolymerization initiator, but does not contain a polyisocyanate.

The photoluminescent printed layer is present over substantially the entire side seam portion. When multiple photoluminescent printed layers are present, one or more of the layers may be present over substantially the entire side seam portion, and in particular, all of the photoluminescent printed layers may be present over substantially the entire side seam portion.

The glossy printed layer may be present over substantially the entire substrate layer.

If the photoluminescent printing layer is a single layer, the thickness of the photoluminescent printing layer is preferably 1 μm or more and 7 μm or less, for example, 1 μm or more, 2 μm or more, or 3 μm or more, and 7 μm or less, or 6 μm, from the viewpoint of providing photoluminescence.

When multiple photoluminescent printed layers are present, the thickness of the photoluminescent printed layers may be 10 μm or more and 40 μm or less. From the viewpoint of design, it is preferable that the thickness is 10 μm or more, 15 μm or more, 20 μm or more, or 25 μm or more, and from the viewpoint of suppressing yellowing, it is preferable that the thickness is 40 μm or less, 35 μm or less, or 30 μm or less.

(Photochromic printing layer: photochromic pigment)
As the luster pigment, for example, a scaly metallic pigment, a pearl pigment, etc. can be used.

As a flake-like metal pigment, for example, aluminum powder, especially aluminum flakes, can be used.

　Pearl pigments can be synthetic mica, natural mica, or pigments made of synthetic mica, natural mica, glass, or alumina flakes coated with titanium oxide or silica.

The content of the glittering pigment in the glittering print layer may be 1% by mass or more and 25% by mass or less, based on the mass of the glittering print layer. This content may be 1% by mass or more, 3% by mass or more, 5% by mass or more, 7% by mass or more, or 9% by mass or more, and may be 25% by mass or less, 22% by mass or less, 20% by mass or less, 17% by mass or less, 15% by mass or less, or 12% by mass or less.

In the photoluminescent printing layer, if the content of pigments other than inorganic photoluminescent pigments is 3% by mass or less, 2% by mass or less, or 1% by mass or less, yellowing becomes more noticeable, making the configuration of the present invention more beneficial. This content may be 0% by mass or more and 3% by mass or less, for example, 0% by mass or more than 0% by mass.

(Photo-glossy printing layer: polyurethane acrylate)
As the polyurethane acrylate, for example, an aliphatic polyurethane acrylate and an aromatic polyurethane acrylate can be used, and among them, an aliphatic polyurethane acrylate is preferably used from the viewpoint of laminate strength. As these polyurethane acrylates, commercially available products can be used.

In the present invention, "aromatic polyurethane acrylate" refers to a polyurethane acrylate having a benzene ring, and "aliphatic polyurethane acrylate" refers to a polyurethane acrylate not having a benzene ring.

(Photopolymerization initiator)
The photopolymerization initiator has less than three benzene rings, that is, two, one or zero benzene rings, and has no amino group.

Such photopolymerization initiators include, for example, a mixture of oxyphenylacetic acid 2-[2-oxo-2-phenylacetoxyethoxy]ethyl ester and oxyphenylacetic acid 2-(2-hydroxyethoxy)ethyl ester, bis(2-phenyl-2-oxoacetic acid)oxybisethylene (Irgacure 754), 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Darocure 1173), etc.

The content of the photopolymerization initiator may be 2 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the aliphatic polyurethane acrylate. This content may be 2 parts by mass or more, 3 parts by mass or more, 4 parts by mass or more, or 5 parts by mass or more, relative to 100 parts by mass of the aliphatic polyurethane acrylate, and may be 10 parts by mass or less, 9 parts by mass or less, 8 parts by mass or less, 7 parts by mass or less, or 6 parts by mass or less.

(Undercoat Printing Layer)
The underprinting layer is a layer of the printing layer that is in direct contact with the printed layer of the base material layer. When a part of the outer sealant layer and a part of the inner sealant layer are overlapped and heat sealed to form a side seam portion to form a cylindrical laminated tube container, the underprinting layer is present over almost the entire side seam portion.

The undercoat printing layer may be present over substantially the entire substrate layer.

The base printing layer preferably contains polyisocyanate from the viewpoint of obtaining laminate strength. In this case, the content of polyisocyanate may be 1% by mass or more and 25% by mass or less, based on the mass of the base printing layer. This content may be 1% by mass or more, 2% by mass or more, 3% by mass or more, or 4% by mass or more, and may be 25% by mass or less, 22% by mass or less, 20% by mass or less, 17% by mass or less, 15% by mass or less, 12% by mass or less, 10% by mass or less, 8% by mass or less, or 6% by mass or less.

Examples of polyisocyanates that can be used include hexamethylene diisocyanate.

From the standpoint of obtaining laminate strength, it is preferable for the base printing layer to be in direct contact with the glossy printing layer.

For the underprinting layer, a composition in which a polyisocyanate has been added to a commercially available ink can be used.

(Other printed layers)
The other printed layer may be an optional printed layer for the purpose of display, decoration, etc. The printed layer can be laminated by any printing means.

<Base layer>
The substrate layer is a non-permeable substrate on which the printing layer is laminated. The substrate layer may be a single layer, or may be a laminate in which multiple layers are laminated, and may include multiple layers of the same type.

The substrate layer may have, for example, a printable layer, a barrier layer, and a reinforcing layer. These layers may be laminated by any lamination means, for example, via an adhesive layer. The adhesive layer may be any of the adhesive layers listed for the outer adhesive layer.

As such a substrate layer, for example, a substrate having the following layer structure can be used:
・LDPE (75μm) / Milky LDPE (160μm) / LDPE (50μm) / PET (12μm) / LLDPE (100μm)
・LLDPE (55μm) / Transparent LDPE (80μm) / EAA (20μm) / AL (12μm) / EMAA (25μm) / PET (12μm)

(Printed layer)
The printable layer is not particularly limited as long as it is a layer that is impermeable to such an extent that the printing layer can be printed thereon, and may be, for example, a resin layer.

For example, thermoplastic resins such as polyolefin resins, vinyl polymers, polyesters, polyamides, etc. can be used alone or in combination of two or more layers as the printing layer. Such thermoplastic resins can be used in the form of a film or extruded resin. The film may be either a stretched film or a non-stretched film.

As the polyolefin resin, for example, a polyethylene resin or a polypropylene resin can be used. For the polyethylene resin, please refer to the description of the outer sealant layer and the inner sealant layer.

In this specification, a polypropylene-based resin is a resin that contains more than 50 mol%, 60 mol% or more, 70 mol% or more, or 80 mol% or more of repeating propylene groups in the polymer main chain, and examples of such resins include polypropylene (PP) homopolymer, random polypropylene (random PP), block polypropylene (block PP), chlorinated polypropylene, acid-modified polypropylene, and derivatives thereof, as well as mixtures thereof.

An example of a vinyl polymer is polyvinyl chloride (PVC).

Examples of polyester include polyethylene terephthalate (PET) and polybutylene terephthalate.

Examples of polyamides include nylons such as Nylon (registered trademark) 6 and Nylon MXD6.

(Barrier Layer)
As the barrier layer, for example, an inorganic material vapor deposition layer, a metal foil layer, an organic material coating layer, or the like can be used.

Examples of inorganic deposition layers that can be used include silica deposition films, aluminum deposition films, alumina deposition films, and silica-alumina deposition films.

The metal foil layer can be, for example, a single metal foil such as aluminum foil, copper foil, or titanium foil, or an alloy foil such as aluminum alloy foil or stainless steel foil.

As the organic coating layer, for example, a vinylidene chloride coating layer or a polyvinylidene fluoride coating layer can be used.

When an inorganic vapor deposition film or an organic coating layer is used as the barrier layer, the thickness of the barrier layer may be 100 nm or more and 5 μm or less. From the viewpoint of ensuring strength and barrier properties, the thickness is preferably 100 nm or more, 200 nm or more, 300 nm or more, 500 nm or more, 700 nm or more, or 1 μm or more, and from the viewpoint of improving handleability as a laminate for a tube, the thickness is preferably 5 μm or less, 4 μm or less, 3 μm or less, or 2 μm or less.

When a metal foil layer is used as the barrier layer, the thickness of the barrier layer may be 3 μm or more and 100 μm or less. From the viewpoint of ensuring strength and barrier properties, the thickness is preferably 3 μm or more, 5 μm or more, 7 μm or more, 10 μm or more, or 15 μm or more, and from the viewpoint of improving handleability as a laminate for a tube, the thickness is preferably 100 μm or less, 80 μm or less, 60 μm or less, 55 μm or less, 50 μm or less, 45 μm or less, 40 μm or less, or 35 μm or less.

(Reinforcing layer)
The reinforcing layer may be a layer composed of a stretched film.

The reinforcing layer may be a stretched film made of, for example, polyester resin, polyamide resin, polypropylene resin, etc.

When the reinforcing layer is composed of a stretched film, the stretched film constituting the reinforcing layer may be, for example, a stretched film obtained by flat method stretching, and may be a uniaxially stretched film or a biaxially stretched film. The biaxially stretched film may be a sequentially biaxially stretched film or a simultaneous biaxially stretched film, or may be a stretched film obtained by carrying out these stretching operations multiple times.

The thickness of the reinforcing layer may be 5 μm or more and 50 μm or less. From the viewpoint of imparting practical time-dependent recovery to the laminated tube, it is preferable that the thickness is 5 μm or more, 7 μm or more, 10 μm or more, 12 μm or more, or 25 μm or more. On the other hand, it is preferable that the thickness of the reinforcing layer is 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 15 μm or less, or 12 μm or less, from the viewpoint of not impairing short-term shape retention and not excessively increasing the total thickness of the laminated tube roll.

<Inner adhesive layer>
The inner adhesive layer is a layer that lies between the substrate layer and the sealant layer, thereby adhering them to one another.

The inner adhesive layer may be any of the adhesive layers listed for the outer adhesive layer. In particular, the inner adhesive layer may be selected according to the material of the base layer, particularly the material of the layer of the base layer closest to the innermost sealant layer.

Laminated tube container
2, a laminated tube container 200 of the present invention has the laminated tube container laminate 100. A part of the outer sealant layer 110 and a part of the inner sealant layer 160 are overlapped and heat sealed to form a side seam portion 210, thereby forming the laminated tube container laminate 100 into a cylindrical shape.

Although not shown, the laminated tube container of the present invention may have a head portion having a shoulder portion and a cap portion, and a tail seal portion located on the opposite side to the head portion.

Laminated tube containers can be filled with contents such as medicines, cosmetics, and food. Examples of contents include toothpaste, moisturizing cream, and sunscreen.

The laminated tube container can be produced, for example, by a method including the following steps:
A process of rolling the laminated tube laminate so that the base material, particularly the sealant layer of the base material, is on the inside, while overlapping and heat-sealing the ends of the laminate to form a side seam to obtain a body portion; and a process of joining a head portion having a shoulder portion and a cap portion to the periphery of the opening of the body portion to obtain a laminated tube container.

The present invention will be specifically explained using examples and comparative examples, but the present invention is not limited to these.

<<Preparation of Laminate>>
Example
As the substrate layer, a laminate having the following layer structure was prepared:
LLDPE (55μm)/Transparent LDPE (80μm)/EAA (20μm)/AL/EMAA (25μm)/PET (12μm)
In the above structure, the LLDPE (55 μm) corresponds to the printing layer.

An LLDPE film (thickness 100 μm) was attached as an inner sealant layer to the PET side of the above laminate using a two-component curing dry lamination adhesive.

Next, a 1 μm thick underprinting layer was laminated over the entire surface of the printed layer. The underprinting layer was made of UV-curable black flexographic ink with added hexamethylene diisocyanate.

Next, a lustrous printing layer (pearl printing layer) was laminated to a thickness of 5 μm in one pass over the entire surface of the base printing layer.

The photoluminescent printing layer was made of a composition obtained by mixing 85 parts by mass of an aliphatic polyurethane acrylate resin (EBECRYL 270, Daicel Allnex), 10 parts by mass of a pearl pigment (Pyrisma, Merck), and 5 parts by mass of a photopolymerization initiator having less than three benzene rings and no amino groups (Irgacure 184, IGM Resins B.V.). The content of the photopolymerization initiator per 100 parts by mass of the aliphatic polyurethane acrylate was 6 parts by mass. The photoluminescent printing layer did not contain polyisocyanate.

The undercoat printing layer and the glittering printing layer were laminated by coating them by flexographic printing under the following conditions, and curing them by irradiating the coating with ultraviolet (UV) rays.
Printing machine: Flexiproof Anilox roll: 180 lines/inch
UV irradiation conditions: 160W

The photoluminescent print layer and the LLDPE film as the outer sealant layer were bonded together via a two-component curing dry lamination adhesive as the outer adhesive layer to produce the laminated tube container laminate of the embodiment.

Comparative Example 1
A laminate for laminated tube containers in Comparative Example 1 was obtained in the same manner as in Example 1, except that a composition in which 5 parts by mass of hexamethylene diisocyanate was added to 95 parts by mass of the composition in Example 1 was used as the glossy printing layer.

Comparative Example 2
A laminate for laminate tube containers of Comparative Example 2 was obtained in the same manner as in Example 1, except that no glittering printed layer was laminated and no isocyanate was contained in the undercoat printed layer.

Comparative Example 3
A laminate for a laminate tube container of Comparative Example 3 was produced in the same manner as in Example 1, except that no glittering printed layer was laminated.

"evaluation"
(Ink reusability)
The inks of the examples and comparative examples were prepared, left at room temperature for 8 hours, and then visually inspected for appearance. The evaluation criteria were as follows:
A: No air bubbles were generated and the product was reusable.
B: Air bubbles were generated and the product could not be reused.

<Lamination strength>
For the examples and comparative example 2 in which the ink reusability was evaluated as "A", the laminated tube container laminates produced were cut into 15 mm wide strips, and the outer sealant layer was peeled off to prepare test pieces. The laminate strength was measured using a tensile tester in accordance with JIS K 6854-3.

The configurations and evaluation results of the examples and comparative examples are shown in Table 1.

From Table 1, it can be seen that the laminate for laminated tube containers of the embodiment, which includes a photoluminescent printed layer made of ink containing a specific combination of polyurethane acrylate and photopolymerization initiator, and which does not contain polyisocyanate, has good ink reusability and laminate strength.

In contrast, it can be seen that the inks of Comparative Examples 1 and 3, in which the inks in the glossy printing layer contain polyisocyanate, do not have good reusability.

Furthermore, from the results of Comparative Example 2, it can be seen that if polyisocyanate is removed from an ink that is not composed of an ink containing a specific combination of polyurethane acrylate and photopolymerization initiator, sufficient laminate strength cannot be obtained.

REFERENCE SIGNS LIST 100 Laminated tube container laminate 110 Outer sealant layer 120 Outer adhesive layer 130 Printed layer 132 Glossy printed layer 134 Base printed layer 136 Other printed layer 140 Base layer 150 Inner adhesive layer 160 Inner sealant layer 200 Laminated tube container 210 Side seam portion

Claims (9)

The laminate includes an outer sealant layer, an outer adhesive layer, one or more printed layers, a substrate layer, an inner adhesive layer, and an inner sealant layer, in that order.
a part of the outer sealant layer and a part of the inner sealant layer are overlapped and heat-sealed to form a side seam portion to form a cylindrical laminated tube container, the printed layer including a glittering printed layer that is present over substantially the entire side seam portion,
The photoluminescent print layer is made of an ultraviolet-curable flexographic photoluminescent ink, and the ultraviolet-curable flexographic photoluminescent ink contains a photoluminescent pigment, a polyurethane acrylate, and a photopolymerization initiator, but does not contain a polyisocyanate;
the photopolymerization initiator has less than three benzene rings and has no amino group;
The outer sealant layer and the inner sealant layer are made of a polyethylene resin,
The base layer has a printable layer, and at least one of the printable layers is in direct contact with the printable layer.
Laminated body for laminated tube containers. The laminate for laminate tube containers according to claim 1, wherein the printed layer further has a base printed layer that is in direct contact with the base layer, and a part of the outer sealant layer and a part of the inner sealant layer are overlapped and heat sealed to form a side seam portion, so that when the laminate tube container is made into a cylindrical laminate tube container, the base printed layer is present over substantially the entire side seam portion. The laminate for laminate tube containers according to claim 2, wherein the undercoat printing layer contains polyisocyanate. The laminate for laminate tube containers according to claim 2 or 3, wherein the photoluminescent printed layer is in direct contact with the base printed layer. The laminate for laminate tube containers according to claim 1 or 2, wherein the content of the photoluminescent pigment is 1% by mass or more and 30% by mass or less relative to the mass of the ultraviolet-curing flexographic photoluminescent ink. The laminate for laminate tube containers according to claim 1 or 2, wherein the content of the photopolymerization initiator is 1% by mass or more and 30% by mass or less relative to the mass of the ultraviolet-curing flexographic photoluminescent ink. The laminate for laminate tube containers according to claim 1 or 2, wherein the printable layer is made of a polyethylene resin. The laminate for laminated tube containers according to claim 1 or 2, wherein the outer adhesive layer is a two-component curing dry lamination adhesive. A laminate tube container comprising the laminate according to claim 1 or 2,
A part of the outer sealant layer and a part of the inner sealant layer are overlapped and heat-sealed to form a side seam portion, thereby forming the laminated tube container laminate into a cylindrical shape.
Laminated tube container.

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