JP2023132348A - Laminate, tube container body, and tube container - Google Patents

Abstract

To provide a laminate which enables manufacture of a packaging container of a tube container body having high recyclability and reduced solvent odor.SOLUTION: A laminate has, at least, a first resin layer, a first adhesive layer having thickness of 2.0 μm or less, a drawn base material, a second adhesive layer having thickness of 2.0 μm or less, and a second resin layer, and further has a design layer on a surface on the first resin layer side and/or a surface on the second resin layer side in the drawn base material, wherein the first resin layer, the drawn base material and the second resin layer contain polyethylene as main components, respectively.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a laminate, a tube container body, and a tube container.

2. Description of the Related Art Tube containers are known as packaging containers that are filled with paste-like semi-liquid materials such as toothpaste paste and facial cleansing cream, and squeezed out for use. A tube container usually includes a tube container body and a cap. The tube container body generally includes a body portion that is closed at one end and open at the other end, and a head portion that has a spout and is connected to the other open end of the body portion. A tube container containing the contents is manufactured by filling the contents into the body before closing one end of the body, and then closing one end of the body.

The body of a conventional tube container body is made of, for example, a polyethylene film as a heat-sealing layer, a polyethylene terephthalate film on which a printing layer is formed as a printing base material, and polyethylene terephthalate on which a vapor-deposited film is formed as a barrier base material. It is manufactured using a packaging material including a film, aluminum foil, etc. (see Patent Document 1). However, it is generally difficult to separate, for example, a packaging container comprising polyethylene film and aluminum foil into their respective films. Therefore, such packaging containers are not suitable for recycling after use, and currently are not actively recycled. Therefore, packaging materials are being considered that include a polyethylene film that has been subjected to a stretching process (stretched polyethylene film) as a base material and a polyethylene film as a heat seal layer (see Patent Document 2).

Japanese Patent Application Publication No. 2010-214768 JP2005-053223A

Packaging materials are manufactured, for example, by laminating a base material and a heat-sealing layer with an adhesive layer interposed therebetween. In the case of a laminate (packaging material) that includes a stretched polyethylene film as a base material and a polyethylene film as a heat seal layer, it is necessary to suppress thermal deterioration of the base material during production. When a laminate is manufactured by performing a drying step after applying the adhesive at a low temperature or for a short period of time in order to suppress thermal deterioration of the base material, a solvent odor originating from the adhesive may remain.

An object of the present disclosure is to provide a laminate that has high recyclability and can produce a packaging container such as a tube container body with reduced solvent odor.

The laminate of the present disclosure includes a first resin layer, a first adhesive layer with a thickness of 2.0 μm or less, a stretched base material, a second adhesive layer with a thickness of 2.0 μm or less, and a first adhesive layer with a thickness of 2.0 μm or less. 2 resin layer, further comprising a design layer on the surface of the stretched base material on the first resin layer side and/or on the surface of the stretched base material on the second resin layer side, the first resin layer, the stretched base material The material and the second resin layer each contain polyethylene as a main component.

According to the present disclosure, it is possible to provide a laminate that has high recyclability and can produce a packaging container such as a tube container body with reduced solvent odor.

FIG. 1 is a schematic cross-sectional view showing one embodiment of the laminate of the present disclosure. FIG. 2 is a schematic cross-sectional view showing one embodiment of the laminate of the present disclosure. FIG. 3 is a schematic cross-sectional view showing one embodiment of the laminate of the present disclosure. FIG. 4 is a schematic cross-sectional view showing an embodiment of the laminate of the present disclosure. FIG. 5 is a perspective view showing an embodiment of a tube container including a tube container main body including a laminate of the present disclosure and a cap. FIG. 6 is a sectional view taken along line AA in FIG.

Embodiments of the present disclosure will be described in detail below. This disclosure may be implemented in many different forms and is not to be construed as limited to the description of the exemplary embodiments below. In order to make the explanation more clear, the drawings may schematically represent the width, thickness, shape, etc. of each layer compared to the embodiment, but this is just an example and does not limit the interpretation of the present disclosure. . In this specification and each figure, elements that are the same as those already explained with respect to the existing figures are denoted by the same reference numerals, and detailed explanations may be omitted as appropriate.

Hereinafter, embodiments of the laminate of the present disclosure will be described using appropriate drawings. In addition, in the following description, the described components (for example, polyethylene, gas barrier resin, additive, white pigment) may be used alone or in combination of two or more.

In the present disclosure, the term "main component" refers to a component whose content in the layer exceeds 50% by mass.

[Laminated body]
The laminate of the present disclosure includes a first resin layer, a first adhesive layer with a thickness of 2.0 μm or less, a stretched base material, a second adhesive layer with a thickness of 2.0 μm or less, and a first adhesive layer with a thickness of 2.0 μm or less. For example, at least two resin layers are provided in this order in the thickness direction of the laminate. The laminate further includes a design layer on the first resin layer side surface and/or the second resin layer side surface of the stretched base material. The first resin layer, the stretched base material, and the second resin layer each contain polyethylene as a main component.

One embodiment of the laminate of the present disclosure is shown in FIGS. 1 to 4.
The laminate 1 in FIG. 1 includes a first resin layer 2, a first adhesive layer 8A, a design layer 4a, a stretched base material 4, a second adhesive layer 8B, and a second resin layer. 6 in this order. The laminate 1 in FIG. 2 includes a first resin layer 2, a first adhesive layer 8A, a stretched base material 4, a design layer 4a, a second adhesive layer 8B, and a second resin layer. 6 in this order.

The laminate 1 in FIG. 3 includes a first resin layer 2, a first adhesive layer 8A, a design layer 4a, a stretched base material 4, a second adhesive layer 8B, and another base material 7. , a third adhesive layer 8C, and a second resin layer 6 in this order. The laminate 1 in FIG. 4 includes a first resin layer 2, a first adhesive layer 8A, a stretched base material 4, a design layer 4a, a second adhesive layer 8B, and another base material 7. , a third adhesive layer 8C, and a second resin layer 6 in this order.

The first resin layer may have a multilayer structure (for example, three resin layers). The second resin layer may have a multilayer structure (for example, three resin layers). The stretched base material may have a multilayer structure (for example, three resin layers).

The first resin layer, the stretched base material, and the second resin layer included in the laminate of the present disclosure are each made of polyethylene, which is the same kind of material. Therefore, the laminate of the present disclosure has high recyclability. The tube container main body including this laminate also has high recyclability.

The content rate of polyethylene in the entire laminate of the present disclosure is preferably 90% by mass or more, more preferably 92% by mass or more. Thereby, it is possible to improve the recyclability of the laminate of the present disclosure and the main body of a tube container (especially a laminate tube container) including the laminate.

In one embodiment, the laminate of the present disclosure does not include any polyethylene terephthalate film, aluminum foil, or vapor-deposited film. Thereby, it is possible to improve the recyclability of the laminate of the present disclosure and the main body of a tube container (especially a laminate tube container) including the laminate.

In this specification, the term "laminate" may refer to the raw fabric itself manufactured on the production line, which has the above-mentioned layer structure, and may refer to each individual piece of the laminate obtained by cutting the raw fabric. It is not particularly limited as long as it has the above layer structure. The individual laminate pieces are used, for example, to form the body of the tube container body.

<First resin layer and second resin layer>
The first resin layer contains polyethylene as a main component. The second resin layer contains polyethylene as a main component. The polyethylene contained in the first resin layer and the polyethylene contained in the second resin layer may be the same or different.

The first resin layer has heat sealability. The second resin layer has heat sealability. Therefore, the first resin layer and the second resin layer can each be melted and fused together by heating.

When the laminate of the present disclosure is used to form the body of a tube container body, the first resin layer is a sealant layer (heat sealing layer) on the outer surface side of the body, and the second resin layer is a sealant layer (heat sealing layer) on the outside of the body. This is the sealant layer (heat seal layer) on the inner surface side. That is, the body includes, from the inside to the outside of the body, a second resin layer having heat sealability, a second adhesive layer, a stretched base material, and a first adhesive layer. and a first resin layer having heat sealability, for example, in this order. In one embodiment, the first resin layer is one surface layer of the laminate, and the second resin layer is the other surface layer of the laminate.

Examples of polyethylene include high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene and very low density polyethylene. Among these, medium density polyethylene, low density polyethylene and linear low density polyethylene are preferred from the viewpoint of heat sealability.

In the present disclosure, the melt flow rate (MFR) of polyethylene may be 0.1 g/10 minutes or more and 50 g/10 minutes or less, and 0.3 g/10 minutes or more and 30 g/10 minutes from the viewpoint of film formability and processability. It may be less than or equal to 0.5 g/10 minutes or more and less than or equal to 10 g/10 minutes. The MFR of polyethylene is measured by method A in accordance with JIS K7210 at a temperature of 190° C. and a load of 2.16 kg.

In the present disclosure, polyethylene with a density of more than 0.945 g/cm ³ can be used as the high-density polyethylene, and polyethylene with a density of more than 0.926 g/cm ³ and 0.945 g/cm ³ or less can be used as the medium-density polyethylene. Polyethylene with a density of more than 0.900 g/cm ³ but not more than 0.926 g/cm ³ can be used as the low-density polyethylene, and as the linear low-density polyethylene, polyethylene with a density of Polyethylene with a density of more than 0.900 g/cm ³ and 0.926 g/cm ³ or less can be used, and as the ultra-low density polyethylene, polyethylene with a density of 0.900 g/cm ³ or less can be used. The density of polyethylene is measured in accordance with JIS K7112 (for example, D method (density gradient tube method, 23° C.)).

Low-density polyethylene is usually polyethylene obtained by polymerizing ethylene using a high-pressure polymerization method (high-pressure low-density polyethylene). Linear low-density polyethylene is usually polyethylene obtained by polymerizing ethylene and a small amount of α-olefin by a low-pressure polymerization method (eg, a polymerization method using a Ziegler-Natta catalyst or a metallocene catalyst).

Polyethylenes having different densities or branches can be obtained by appropriately selecting the polymerization method. For example, a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst is used as a polymerization catalyst, and one-stage polymerization is performed by any one of gas phase polymerization, slurry polymerization, solution polymerization, and high-pressure ionic polymerization. Alternatively, it is preferable to carry out the polymerization in multiple stages of two or more stages.

In the present disclosure, polyethylene includes copolymers of ethylene and other monomers (hereinafter also referred to as "ethylene copolymers"). In the present disclosure, the content of ethylene-derived structural units in polyethylene is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, and particularly preferably 90 mol% or more or 95 mol%. That's all. The content ratio can be measured, for example, by nuclear magnetic resonance (NMR).

Examples of the ethylene copolymer include copolymers of ethylene and α-olefin having 3 or more and 20 or less carbon atoms. Examples of α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1 -octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene and 6-methyl-1-heptene. Polyethylene may be a copolymer of ethylene and vinyl acetate or (meth)acrylic acid ester.

As the polyethylene, biomass-derived polyethylene (hereinafter also referred to as "biomass polyethylene") obtained by polymerizing a monomer containing biomass-derived ethylene may be used. Since such biomass polyethylene is a carbon neutral material, it is possible to reduce the environmental load in producing the laminate of the present disclosure.

As the polyethylene, polyethylene recycled by mechanical recycling or chemical recycling may be used. Thereby, the environmental load caused by the laminate or the packaging material can be reduced. Mechanical recycling generally involves pulverizing recovered polyethylene film, washing it with alkali to remove dirt and foreign matter from the film surface, and then drying it at high temperature and reduced pressure for a certain period of time to remain inside the film. This method involves decontaminating the film by diffusing contaminants, removing dirt from the film, and then returning it to polyethylene. Chemical recycling is generally a method in which recovered polyethylene films and the like are decomposed to the monomer level and the monomers are polymerized again to obtain polyethylene.

The content of polyethylene in the first resin layer is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more. The content rate of polyethylene in the second resin layer is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more. With such a configuration, for example, the recyclability of a packaging container including the laminate of the present disclosure can be improved.

The first resin layer may contain additives. The second resin layer may contain additives. Examples of additives include crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins. It will be done.

The second resin layer may contain a pigment such as a white pigment. With such a configuration, it is possible to impart hiding power (for example, white hiding feeling) to the laminate without using ink such as white ink. When using ink, it is necessary to volatilize and remove the solvent, which tends to place a burden on the environment during the production of the laminate, but with the above configuration, the environmental burden during the production of the laminate can be reduced.

Examples of white pigments include titanium oxide, barium titanate, strontium titanate, aluminum oxide, magnesium oxide, zinc oxide, barium sulfate, magnesium carbonate, barium carbonate, zirconium oxide, calcium carbonate, white carbon, clay, talc, and sulfuric acid. Examples include barium.

The second resin layer may be, for example, a polyethylene film whose total light transmittance measured according to JIS K7375 is 10% or more and 40% or less. Thereby, for example, hiding power can be imparted to the laminate.

The first resin layer may have a multilayer structure. The second resin layer may have a multilayer structure. Examples of the multilayer structure include a structure including a layer containing medium density polyethylene, a layer containing medium density polyethylene, and a layer containing medium density polyethylene.

The first resin layer may be a film containing polyethylene as a main component. The second resin layer may be a film containing polyethylene as a main component. The film may be a stretched film or an unstretched film. The film is preferably an unstretched film from the viewpoint of heat sealability. The second resin layer may be a film containing polyethylene and a white pigment.

The surface of the first resin layer may be subjected to surface treatment. The surface of the second resin layer may be subjected to surface treatment. Thereby, the adhesion between these resin layers and the layer adjacent to the resin layer can be improved. Examples of surface treatment methods include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and/or nitrogen gas, glow discharge treatment, and oxidation treatment using chemicals. Examples include chemical treatment.

An anchor coat layer may be formed on the surface of the first resin layer using a conventionally known anchor coat agent. An anchor coat layer may be formed on the surface of the second resin layer using a conventionally known anchor coat agent.

The thickness of the first resin layer is preferably 30 μm or more and 250 μm or less, more preferably 50 μm or more and 200 μm or less. The thickness of the second resin layer is preferably 30 μm or more and 250 μm or less, more preferably 50 μm or more and 200 μm or less. When the thickness is 30 μm or more, the heat sealability can be further improved. When the thickness is 250 μm or less, the workability of the laminate can be improved.

The first resin layer and the second resin layer can be produced, for example, by forming a resin composition containing polyethylene into a film using a T-die method, an inflation method, or the like. The first resin layer and the second resin layer can be laminated, for example, via an adhesive layer, which will be described later.

The second resin layer may include a polyethylene layer and a gas barrier resin layer. The second resin layer includes, for example, a first polyethylene layer, a first adhesive resin layer, a gas barrier resin layer, a second adhesive resin layer, and a second polyethylene layer in this order. You may prepare. By including the gas barrier resin layer in the second resin layer, the barrier properties such as oxygen barrier properties and water vapor barrier properties in the laminate can be improved without using a different material such as a vapor-deposited film or aluminum foil. In the following description, unless the first polyethylene layer and the second polyethylene layer are particularly distinguished, they will simply be referred to as a polyethylene layer.

When the second resin layer includes a gas barrier resin layer, the content of polyethylene is preferably more than 50% by mass and 95% by mass or less, more preferably 55% by mass or more and 90% by mass, based on the second resin layer. The content is preferably 60% by mass or more and 85% by mass or less. When the second resin layer includes a gas barrier resin layer, the content ratio of the gas barrier resin is preferably 1% by mass or more and 30% by mass or less, more preferably 3% by mass or more and 20% by mass or less, based on the second resin layer. It is not more than 5% by mass, more preferably not less than 5% by mass and not more than 15% by mass. With such a configuration, for example, the balance between recyclability and gas barrier properties of the laminate can be improved.

The gas barrier resin layer contains a gas barrier resin.
Examples of gas barrier resins include ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile; polyamides such as nylon 6, nylon 6,6, and polymethaxylylene adipamide; polyester; polyurethane; ) acrylic resin. Among these, EVOH is preferred from the viewpoint of heat resistance and gas barrier properties.

EVOH can be obtained, for example, by copolymerizing ethylene and a vinyl ester monomer and then saponifying the copolymerization. The copolymerization of ethylene and the vinyl ester monomer can be carried out by any known polymerization method, such as solution polymerization, suspension polymerization, emulsion polymerization, etc.

Vinyl acetate is generally used as the vinyl ester monomer, but other vinyl ester monomers may also be used. Examples of other vinyl ester monomers include vinyl formate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, and vinyl versatate. Aliphatic vinyl esters include aromatic vinyl esters such as vinyl benzoate.

The content ratio of structural units derived from ethylene (ethylene content ratio) in the ethylene-vinyl alcohol copolymer (EVOH) is preferably 20 mol% or more and 60 mol% or less, more preferably 25 mol% or more and 50 mol% or less. be. When the ethylene content is at least the lower limit, for example, the workability of the laminate can be improved. When the ethylene content is below the upper limit, for example, the oxygen barrier properties and/or water vapor barrier properties of the laminate can be improved. The ethylene content rate is measured by NMR method.

From the viewpoint of heat resistance, the melting point (Tm) of EVOH is preferably 140°C or more and 200°C or less, more preferably 145°C or more and 195°C or less, and even more preferably 150°C or more and 190°C or less. The Tm of EVOH is obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

The average saponification degree of the vinyl ester component in EVOH may be 90 mol% or more, 95 mol% or more, or 99 mol% or more from the viewpoint of gas barrier properties. The average degree of saponification is measured in accordance with JIS K6726 (for EVOH, a solution uniformly dissolved in a water/methanol solvent is used).

The melt flow rate (MFR) of EVOH may be 0.1 g/10 minutes or more and 50 g/10 minutes or less, or 0.3 g/10 minutes or more and 30 g/10 minutes or less, from the viewpoint of film formability and processability. It may be 0.5 g/10 minutes or more and 10 g/10 minutes or less. The MFR of EVOH is measured in accordance with ASTM D1238 at a temperature of 190°C and a load of 2.16 kg, but the measurement temperature may be 210°C depending on the melting point of EVOH.

EVOH may be modified by urethanization, acetalization, cyanoethylation, oxyalkylenation, etc. by a known method.

The content ratio of the gas barrier resin in the gas barrier resin layer is preferably 50% by mass or more, more preferably 75% by mass or more, still more preferably 80% by mass or more, 85% by mass or more, or 90% by mass or more. Thereby, for example, barrier properties such as oxygen barrier properties and water vapor barrier properties of the laminate can be improved.

The thickness of the gas barrier resin layer may be 3 μm or more and 30 μm or less, or 5 μm or more and 20 μm or less. When the thickness is at least the lower limit, the effect of the gas barrier resin layer can be improved, for example. When the thickness is below the upper limit, for example, the recyclability of the laminate can be improved. The ratio of the thickness of the gas barrier resin layer to the total thickness of the second resin layer may be 3% or more and 20% or less, or 5% or more and 15% or less.

The polyethylene layer contains polyethylene as a main component.
Details of the polyethylene are as described above. Examples of the polyethylene contained in the polyethylene layer include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene. Density polyethylene and linear low density polyethylene are preferred. As the polyethylene, biomass polyethylene or mechanically recycled or chemically recycled polyethylene may be used.

The content of polyethylene in the polyethylene layer is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more. With such a configuration, for example, the recyclability of a packaging container including the laminate of the present disclosure can be improved.

The polyethylene layer may contain the above additives.

The ratio of the thickness of the first polyethylene layer to the total thickness of the second resin layer may be 10% or more and 45% or less, 15% or more and 43% or less, or 20% or more and 40% or less. The ratio of the thickness of the second polyethylene layer to the total thickness of the second resin layer may be 10% or more and 45% or less, 15% or more and 43% or less, or 20% or more and 40% or less.

The second resin layer may include an adhesive resin layer between the polyethylene layer and the gas barrier resin layer. Thereby, for example, the adhesion between the polyethylene layer and the gas barrier resin layer can be improved.

The adhesive resin layer contains adhesive resin.
Examples of adhesive resins include polyolefins such as polyethylene, modified polyolefins, vinyl resins, polyethers, polyesters, polyamides, polyurethanes, silicone resins, epoxy resins, and phenol resins. Among these, from the viewpoint of recyclability and adhesion, polyolefins and modified polyolefins are preferred, and modified polyolefins such as acid-modified polyolefins are more preferred. Examples of modified polyolefins include modified polyolefins (particularly graft-modified polyolefins) with unsaturated carboxylic acids such as maleic acid and fumaric acid, or acid anhydrides, esters, or metal salts thereof. Among the adhesive resins, from the viewpoint of obtaining a configuration suitable for monomaterial packaging materials, modified polyolefins such as modified polyethylene are preferred, acid-modified polyolefins such as acid-modified polyethylene are more preferred, and maleic anhydride-modified polyethylene is even more preferred. .

The adhesive resin layer may contain the above additive.

The ratio of the thickness of the first adhesive resin layer to the total thickness of the second resin layer may be 1% or more and 20% or less, 3% or more and 18% or less, or 5% or more and 15% or less. . The ratio of the thickness of the second adhesive resin layer to the total thickness of the second resin layer may be 1% or more and 20% or less, 3% or more and 18% or less, or 5% or more and 15% or less. .

In one embodiment, the second resin layer including the gas barrier resin layer is a coextruded resin film. The coextruded resin film can be produced by, for example, forming a film using an inflation method or a T-die method. The second resin layer including the gas barrier resin layer includes, for example, a linear low-density polyethylene layer, an adhesive resin layer, an ethylene-vinyl alcohol copolymer layer, an adhesive resin layer, and a linear low-density polyethylene layer. For example, a coextruded resin film may be prepared in this order.

<Stretched base material>
The stretched base material contains polyethylene as a main component, that is, it contains polyethylene in an amount exceeding 50% by mass. Since the resin material constituting the stretched base material is polyethylene, which is the same type of resin material as the resin materials constituting the first resin layer and the second resin layer, the laminate having such a configuration can be used as a monomer. It can be suitably used as a packaging material for producing material packaging containers.

For example, examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene, which are classified as the same type of resin material. On the other hand, for example, polyethylene and polyester are not classified as the same type of resin material.

From the viewpoint of strength and heat resistance, the stretched base material preferably contains at least one selected from medium density polyethylene and high density polyethylene. As the polyethylene, biomass polyethylene or mechanically recycled or chemically recycled polyethylene may be used.

From the viewpoint of film formability and processability, the MFR of the polyethylene constituting the stretched base material is preferably 0.1 g/10 minutes or more and 50 g/10 minutes or less, more preferably 0.2 g/10 minutes or more and 30 g/10 minutes. Below, it is more preferably 0.2 g/10 minutes or more and 10 g/10 minutes or less, particularly preferably 0.2 g/10 minutes or more and 5.0 g/10 minutes or less.

For example, when producing a stretched base material by the T-die method, the MFR of polyethylene constituting the stretched base material is preferably 3.0 g/10 minutes or more and 20 g/10 minutes or less from the viewpoint of film formability and processability. . For example, when producing a stretched base material by the inflation method, the MFR of the polyethylene constituting the stretched base material is preferably 0.2 g/10 minutes or more and 5.0 g/10 minutes or less from the viewpoint of film formability and processability. be.

From the viewpoint of heat resistance, the melting point of the polyethylene constituting the stretched base material is preferably 100°C or more and 140°C or less, more preferably 110°C or more and 140°C or less, and still more preferably 120°C or more and 140°C or less.

The content of polyethylene in the stretched base material is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. With such a configuration, for example, the recyclability of the laminate can be improved. When the stretched base material has a multilayer structure, the polyethylene content in each layer constituting the stretched base material is independently preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass. That's all. With such a configuration, for example, the recyclability of the laminate can be improved.

The stretched base material may contain the above additives.

In one embodiment, the haze of the stretched base material may be 25% or less, 15% or less, or 10% or less. The lower limit of haze may be 0.1% or 1%. The haze of the stretched substrate is measured in accordance with JIS K7136.

The stretched substrate may contain a pigment such as a white pigment. With such a configuration, it is possible to impart hiding power (for example, white hiding feeling) to the laminate without using ink such as white ink. When using ink, it is necessary to volatilize and remove the solvent, which tends to place a burden on the environment during the production of the laminate, but with the above configuration, the environmental burden during the production of the laminate can be reduced. When using such a stretched base material, the laminate preferably includes a design layer on the surface of the stretched base material on the first resin layer side.

Examples of white pigments include titanium oxide, barium titanate, strontium titanate, aluminum oxide, magnesium oxide, zinc oxide, barium sulfate, magnesium carbonate, barium carbonate, zirconium oxide, calcium carbonate, white carbon, clay, talc, and sulfuric acid. Examples include barium.

The stretched base material may be, for example, a polyethylene film whose total light transmittance measured according to JIS K7375 is 10% or more and 40% or less. Thereby, for example, hiding power can be imparted to the laminate.

The stretched base material is a polyethylene base material that has been subjected to a stretching process. The stretching treatment can improve, for example, the printability, heat resistance, and strength of the polyethylene base material. Such a stretched base material can satisfy physical properties required as a base material constituting the body of a tube container, for example.

The stretching may be uniaxial or biaxial. In one embodiment, the stretching ratio in the longitudinal direction (MD) of the stretched base material is preferably 2 times or more and 10 times or less, more preferably 3 times or more and 7 times or less. In one embodiment, the stretching ratio in the transverse direction (TD) of the stretched base material is preferably 2 times or more and 10 times or less, more preferably 3 times or more and 7 times or less. When the stretching ratio is 2 times or more, for example, the rigidity, strength, and heat resistance of the polyethylene base material can be improved, the suitability for printing on the polyethylene base material can be improved, and the transparency of the polyethylene base material can be improved. When the stretching ratio is 10 times or less, for example, good stretching can be performed without causing breakage of the film. In one embodiment, the stretched base material is a uniaxially stretched film, more specifically, a uniaxially stretched film that has been stretched in the longitudinal direction (MD).

The stretched base material may be subjected to the above-mentioned surface treatment. Thereby, for example, the adhesion between the stretched base material and the layer laminated on the stretched base material can be improved. An anchor coat layer may be formed on the surface of the stretched base material using a conventionally known anchor coat agent.

The thickness of the stretched base material is preferably 10 μm or more and 60 μm or less, more preferably 15 μm or more and 50 μm or less. When the thickness of the stretched base material is 10 μm or more, rigidity and strength can be improved. When the thickness of the stretched base material is 60 μm or less, workability can be improved.

The stretched base material may have a single layer structure or a multilayer structure. Hereinafter, a stretched base material having a multilayer structure will also be referred to as a "stretched multilayer base material." A stretched multilayer base material is preferable from the viewpoint of improving its strength, heat resistance, and stretching suitability.

The stretched multilayer base material has a multilayer structure of two or more layers. In one embodiment, the number of layers of the stretched multilayer base material is 2 to 7 layers, for example, 3 to 7 layers, or 3 to 5 layers. The number of layers in the stretched multilayer base material is preferably an odd number, for example, 3 layers, 5 layers, or 7 layers. When the stretched multilayer base material has a multilayer structure, the balance among rigidity, strength, heat resistance, printability, and stretchability can be improved. It is preferable that each layer of the stretched multilayer base material also contains polyethylene as a main component.

Hereinafter, several examples of embodiments of the stretched multilayer base material will be described. Hereinafter, a layer in which the content rate of high-density polyethylene is 80% by mass or more is referred to as a "high-density polyethylene layer", and a layer in which the content rate of medium-density polyethylene is 80% by mass or more is referred to as a "medium-density polyethylene layer". However, a layer containing 80% by mass or more of low-density polyethylene is described as a "low-density polyethylene layer," and a layer containing 80% by mass or more of linear low-density polyethylene is described as "linear low-density polyethylene layer." A layer in which the content of ultra-low density polyethylene is 80% by mass or more is referred to as an "ultra-low density polyethylene layer."

The stretched multilayer base material of the first embodiment includes a high-density polyethylene layer and a medium-density polyethylene layer in this order in the thickness direction. When the surface resin layer of the stretched base material is a high-density polyethylene layer, for example, the strength and heat resistance of the stretched base material can be improved. By providing the stretched base material with a medium density polyethylene layer, for example, the stretching suitability of the laminate before stretching can be improved.

The stretched multilayer base material of the second embodiment includes a high-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer in this order in the thickness direction. With such a configuration, for example, the strength and heat resistance of the stretched base material can be improved, the occurrence of curl in the stretched base material can be suppressed, and the stretching suitability of the laminate before stretching can be improved.

The stretched multilayer base material of the third embodiment includes a high-density polyethylene layer, a medium-density polyethylene layer, a low-density polyethylene layer, a linear low-density polyethylene layer, or an ultra-low-density polyethylene layer (for simplicity, these The three layers are collectively referred to as a "low-density polyethylene layer, etc."), a medium-density polyethylene layer, and a high-density polyethylene layer in this order in the thickness direction. With such a configuration, for example, the stretching suitability of the laminate before stretching can be improved, the strength and heat resistance of the stretched base material can be improved, and the occurrence of curl in the stretched base material can be suppressed.

In another embodiment, the stretched multilayer base material includes a high-density polyethylene layer, a high-density polyethylene layer, a blend layer of medium-density polyethylene and high-density polyethylene, a high-density polyethylene layer, and a high-density polyethylene layer. A stretched base material provided in this order in the thickness direction; a medium-density polyethylene layer, a high-density polyethylene layer, a linear low-density polyethylene layer, a high-density polyethylene layer, and a medium-density polyethylene layer in this order in the thickness direction Also included are stretched substrates.

In addition, a high-density polyethylene layer, a blend layer of high-density polyethylene and medium-density polyethylene, a low-density polyethylene layer, etc., a blend layer of high-density polyethylene and medium-density polyethylene, and a high-density polyethylene layer are arranged in the thickness direction. A stretched base material prepared in this order is also included.

The stretched multilayer base material of the fourth embodiment has a medium density polyethylene layer, a high density polyethylene layer, a blend layer of medium density polyethylene and high density polyethylene, a high density polyethylene layer, and a medium density polyethylene layer. Prepare in this order horizontally. With such a configuration, for example, the printing suitability of the stretched base material can be improved, the strength and heat resistance can be improved, and the stretching suitability of the laminate before stretching can be improved.

The stretched multilayer base material of the fifth embodiment includes a medium density polyethylene layer, a medium density polyethylene layer, a blend layer of medium density polyethylene and linear low density polyethylene, a medium density polyethylene layer, and a medium density polyethylene layer. are provided in this order in the thickness direction. With such a configuration, for example, the printing suitability of the stretched base material can be improved, the strength and heat resistance can be improved, and the stretching suitability of the laminate before stretching can be improved.

The stretched multilayer base material of the sixth embodiment includes a blend layer of medium-density polyethylene and high-density polyethylene, a blend layer of medium-density polyethylene and linear low-density polyethylene, a linear low-density polyethylene layer, and a medium-density A blend layer of polyethylene and linear low density polyethylene and a blend layer of medium density polyethylene and high density polyethylene are provided in this order in the thickness direction. With such a configuration, for example, the printing suitability of the stretched base material can be improved, the strength and heat resistance can be improved, and the stretching suitability of the laminate before stretching can be improved.

The stretched multilayer base material of the seventh embodiment includes a blend layer of high-density polyethylene and medium-density polyethylene, a medium-density polyethylene layer, a blend layer of linear low-density polyethylene and medium-density polyethylene, and a medium-density polyethylene layer. , and a blend layer of high-density polyethylene and medium-density polyethylene in this order in the thickness direction. With such a configuration, for example, the printing suitability of the stretched base material can be improved, the strength and heat resistance can be improved, and the stretching suitability of the laminate before stretching can be improved.

The stretched multilayer base material of the eighth embodiment includes a first layer containing medium density polyethylene and high density polyethylene, a second layer containing high density polyethylene, and a second layer containing linear low density polyethylene. A fourth layer containing high-density polyethylene, and a fifth layer containing medium-density polyethylene and high-density polyethylene are provided in this order in the thickness direction. The second layer and the fourth layer may each independently further contain low density polyethylene. Thereby, the balance between heat resistance, rigidity, and workability of the stretched base material can be further improved. The third layer may further contain low density polyethylene.

The thickness of each of the second layer and the fourth layer may be independently from 0.5 μm to 15 μm, from 1 μm to 10 μm, and from 1 μm to 8 μm. Thereby, the heat resistance of the stretched base material can be further improved. The thickness of the third layer may be 1 μm or more and 50 μm or less, 2 μm or more and 40 μm or less, or 5 μm or more and 30 μm or less. Thereby, the balance between heat resistance, rigidity, and stretchability can be further improved.

In the stretched multilayer base material of the fourth to eighth embodiments, the thickness of each of the two surface resin layers may be independently from 0.5 μm to 10 μm, from 1 μm to 8 μm, and from 1 μm to 5 μm. The following may be used. Thereby, for example, the heat resistance and printability of the stretched base material can be further improved. In the stretched multilayer base materials of the fourth to eighth embodiments, the thickness of each of the two surface resin layers is preferably smaller than the total thickness of the three inner layers (multilayer intermediate layer). The ratio between the thickness of each of the two surface resin layers and the total thickness of the multilayer intermediate layer (surface resin layer/multilayer intermediate layer) may be 0.05 or more and 0.8 or less, and 0.1 or more and 0.7 or less. It may be 0.1 or more and 0.4 or less. Thereby, for example, the rigidity, strength, and heat resistance of the stretched base material can be further improved.

At least one layer selected from each layer constituting the stretched multilayer base material may contain a slip agent. Thereby, for example, the workability of the stretched base material can be improved. For example, in the stretched multilayer base material of the eighth embodiment described above, the third layer may contain a slip agent, or all of the first to fifth layers may contain a slip agent. Examples of slip agents include amide lubricants, fatty acid esters such as glycerin fatty acid esters, hydrocarbon waxes, higher fatty acid waxes, metal soaps, hydrophilic silicones, silicone-modified (meth)acrylic resins, silicone-modified epoxy resins, and silicones. Examples include modified polyethers, silicone-modified polyesters, block-type silicone (meth)acrylic copolymers, polyglycerol-modified silicones, and paraffins. Among the slip agents, amide-based lubricants are preferred. Examples of amide lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Among these, unsaturated fatty acid amides are preferred, and erucic acid amides are more preferred.

In the stretched multilayer base material, the content of the slip agent in the layer containing the slip agent may be, for example, 0.01% by mass or more and 3% by mass or less, or 0.03% by mass or more and 1% by mass or less. Thereby, the workability of the stretched base material can be further improved.

The stretched multilayer base material may include the gas barrier resin layer described above. By including the gas barrier resin layer in the stretched multilayer base material, the barrier properties such as oxygen barrier properties and water vapor barrier properties in the laminate can be improved without using different materials such as vapor-deposited films and aluminum foils. Such a stretched multilayer base material may include a polyethylene layer and a gas barrier resin layer, for example, a first polyethylene layer, a first adhesive resin layer, a gas barrier resin layer, and a second gas barrier resin layer. The adhesive resin layer and the second polyethylene layer may be provided in this order, for example, a medium density polyethylene layer, an adhesive resin layer, an ethylene-vinyl alcohol copolymer layer, an adhesive resin layer, and a medium density polyethylene layer. It may be a base material comprising in this order a linear low density polyethylene layer, an adhesive resin layer, an ethylene-vinyl alcohol copolymer layer, an adhesive resin layer and a linear low density polyethylene layer in this order. Details of the gas barrier resin layer such as the polyethylene layer, the adhesive resin layer, and the ethylene-vinyl alcohol copolymer layer are as described above for the second resin layer comprising the gas barrier resin layer.

The stretched base material can be manufactured by, for example, forming a film of polyethylene or a polyethylene composition and stretching it by an inflation method or a T-die method. The stretched multilayer base material can be manufactured by, for example, forming a laminate by forming a plurality of polyethylenes or polyethylene compositions into films by an inflation method or a T-die method, and stretching the obtained laminate. The stretching treatment can improve the transparency, rigidity, strength, and heat resistance of the polyethylene layer, and the stretched base material can be suitably used, for example, as a base material for packaging materials. Stretching can also be carried out in an inflation film forming machine.

In one embodiment, the stretched multilayer base material is a coextruded resin film, and each layer constituting the stretched multilayer base material is a coextruded resin layer. The coextruded resin film can be produced by, for example, forming a film using an inflation method or a T-die method.

In one embodiment, the stretched multilayer base material is obtained by stretching a laminate (precursor) having a multilayer structure. Specifically, a laminate can be manufactured by coextruding resin materials constituting each layer into a tube shape. Alternatively, a laminate can be manufactured by coextruding the resin materials constituting each layer into a tube shape, and then pressing the opposing layers together using a rubber roll or the like. By manufacturing a laminate using such a method, the number of defective products can be significantly reduced and production efficiency can be improved.

<Other base materials (intermediate base materials)>
The laminate of the present disclosure includes another base material (intermediate base material) between the first resin layer and the second resin layer, for example, between the second adhesive layer and the second resin layer. It may further include. Other base materials contain polyethylene as a main component. Examples of other base materials include the coextruded resin film described as the second resin layer including the gas barrier resin layer. Regarding the coextruded resin film, a configuration similar to that of the second resin layer including the gas barrier resin layer can be adopted. Since the second resin layer including the gas barrier resin layer is as described above, detailed description thereof will be omitted in this section.

<Design layer>
The laminate of the present disclosure includes a design layer such as a printed layer. The laminate of the present disclosure may include a design layer on one surface or both surfaces of the stretched base material. The design layer may be provided on the surface of the stretched base material on the first resin layer side, or may be provided on the surface of the stretched base material on the second resin layer side. The design layer is usually in contact with the stretched base material.

In one embodiment, the laminate of the present disclosure includes a printed base material including a stretched base material and a printed layer provided on at least one surface of the stretched base material.

The design layer has an image. Examples of images include characters, figures, patterns, symbols, and combinations thereof. The image may include textual information such as the product name, the name of the contents in the packaging container, the manufacturer, and the name of raw materials. The image may be a solid color (a so-called solid image).

The design layer contains, for example, a colorant and a resin component.
The design layer is formed using, for example, a resin composition such as a thermoplastic resin composition, a thermosetting resin composition, and an energy ray-curable resin composition, each containing a colorant. The design layer contains, for example, a resin component such as a thermoplastic resin, a cured product of a thermosetting resin, or a cured product of an energy ray-curable resin, and a colorant.

The thermoplastic resin composition contains a thermoplastic resin and a colorant. Examples of the thermoplastic resin include polyolefin, chlorinated polyolefin, polystyrene, (meth)acrylic resin, vinyl resin, acetal resin, polyester, polyurethane, polycarbonate, polyamide, polyimide, cellulose resin, petroleum resin, and fluororesin. The thermoplastic resin composition may contain the above additives.

The thermosetting resin composition is a composition that contains a thermosetting resin, a colorant, and, if necessary, a curing agent, and is cured by heating. The thermosetting resin composition is, for example, a so-called thermosetting ink. Examples of thermosetting resins include phenolic resins, melamine resins, urea resins, epoxy resins, unsaturated polyesters, thermosetting polyurethanes, and silicone resins; and polyester (meth)acrylates, urethane (meth)acrylates, and epoxy (meth)acrylates. Examples include (meth)acrylic thermosetting resins such as acrylate, polyether (meth)acrylate, polyol (meth)acrylate, melamine (meth)acrylate, and triazine (meth)acrylate. Examples of the curing agent include epoxy curing agents and isocyanate curing agents. The thermosetting resin composition may contain the above additives.

The energy ray curable resin composition is a composition that contains a compound having an energy ray curable functional group (hereinafter also referred to as "energy ray curable compound") and a colorant, and is cured by energy ray irradiation. The energy ray curable resin composition is, for example, a so-called ultraviolet curable ink, preferably a (meth)acrylic ultraviolet curable ink.

Examples of energy rays include electromagnetic waves such as ultraviolet rays, infrared rays, X-rays, and γ-rays; and charged particle beams such as electron beams, proton beams, and neutron beams. Among these, ultraviolet rays are preferred from the viewpoint of curing speed, availability of irradiation source, and cost. Examples of ultraviolet radiation sources include mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, metal halides, and LEDs. The amount of ultraviolet irradiation is, for example, 5 mJ/cm ² or more and 5,000 mJ/cm ² or less.

Examples of energy ray-curable functional groups include ethylenically unsaturated groups such as (meth)acryloyl groups, vinyl groups, and allyl groups; as well as epoxy groups and oxetanyl groups.

Examples of the energy ray-curable compound include compounds having an ethylenically unsaturated group, preferably compounds having two or more ethylenically unsaturated groups, and preferably polyfunctional (meth)acrylate compounds. As the polyfunctional (meth)acrylate compound, both monomers and oligomers can be used.

Examples of polyfunctional (meth)acrylate monomers include ethylene glycol di(meth)acrylate, bisphenol A tetraethoxy di(meth)acrylate, bisphenol A tetrapropoxy di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. ) Bifunctional (meth)acrylate monomers such as acrylate; trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol tetra Tri- or higher functional (meth)acrylate monomers such as (meth)acrylate and isocyanuric acid-modified tri(meth)acrylate can be mentioned. The number of energy ray-curable functional groups of the polyfunctional (meth)acrylate monomer is preferably 2 or more and 6 or less, more preferably 2 or more and 3 or less.

The polyfunctional (meth)acrylate monomer may have a part of its molecular skeleton modified, and for example, monomers modified with ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, etc. can be used.

Examples of the polyfunctional (meth)acrylate oligomer include polyester (meth)acrylate, urethane (meth)acrylate, epoxy (meth)acrylate, and polyether (meth)acrylate.

When the energy ray curable compound is an ultraviolet curable compound, the energy ray curable composition (ultraviolet ray curable resin composition) should contain at least one selected from a photopolymerization initiator and a photopolymerization accelerator. is preferred.

Examples of the photopolymerization initiator include acetophenones, benzophenones, thioxanthones, α-hydroxyalkylphenones, Michler's ketones, benzoin, benzyl dimethyl ketal, benzoyl benzoate, and α-acyl oxime esters.

The photopolymerization accelerator is a component that can reduce polymerization inhibition caused by air during curing and accelerate the curing rate, and examples thereof include p-dimethylaminobenzoic acid isoamyl ester and p-dimethylaminobenzoic acid ethyl ester.
The energy ray curable resin composition may contain the above additives.

Examples of the coloring agent include pigments such as inorganic pigments and organic pigments; dyes such as acid dyes, direct dyes, disperse dyes, oil-soluble dyes, metal-containing oil-soluble dyes, and sublimable dyes. Specific examples of the pigment include titanium oxide, zinc white, carbon black, iron oxide, iron yellow, ultramarine blue, metallic pigment, pearl pigment, and fluorescent pigment. The design layer may be a high brightness layer having a high metallic luster.

The content ratio of the resin component in the design layer may be 10% by mass or more and 99% by mass or less, 30% by mass or more and 97% by mass or less, or 50% by mass or more and 95% by mass or less. The content ratio of the colorant in the design layer may be 1% by mass or more and 90% by mass or less, 3% by mass or more and 70% by mass or less, or 5% by mass or more and 50% by mass or less.

The composition for a design layer can contain an organic solvent or water from the viewpoint of improving coating properties and the like. Examples of the organic solvent include hydrocarbons such as toluene and xylene; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate, cellosolve acetate, and butyl cellosolve acetate; and alcohols such as propanol.

For example, a composition for a design layer is applied to a stretched base material and dried, and then, in the case of a thermosetting resin composition, it is heated at a temperature necessary for curing, and in the case of an energy beam-curable resin composition, it is heated with energy rays. A design layer can be formed by irradiating with. If the composition for a design layer does not contain an organic solvent or water, drying is not necessary.

Examples of methods for forming the design layer include letterpress printing, flexographic printing, gravure printing, offset printing, screen printing, inkjet printing, and thermal transfer printing. When forming the design layer by letterpress printing or flexographic printing, it is preferable to use an energy ray curable resin composition, and more preferably to use an ultraviolet ray curable resin composition. The design layer may contain, for example, a sublimable dye. The design layer of this embodiment can be formed, for example, by sublimation transfer printing using a thermal transfer sheet.

The thickness of the design layer is preferably 0.01 μm or more and 30 μm or less, more preferably 0.5 μm or more and 10 μm or less, and even more preferably 1 μm or more and 5 μm or less.
<Adhesive layer>
The laminate of the present disclosure includes a first adhesive layer between the first resin layer and the stretched base material. The laminate of the present disclosure includes a second adhesive layer between the stretched base material and the second resin layer. The adhesive layer functions as an adhesive layer for both of the above. When the laminate further includes other base materials, the laminate may further include a third adhesive layer.

The adhesive may be a one-component curing adhesive, a two-component curing adhesive, or a non-curing adhesive. The adhesive is a solvent-free adhesive. Solvent-free adhesives are a method in which the adhesive is applied to an object and then bonded to another object without going through the process of heating to volatilize the organic solvent in the coating film, the so-called non-solvent laminating method. An adhesive used for In the case of a two-component curing adhesive, neither the base agent nor the curing agent constituting the adhesive substantially contains an organic solvent. If the constituent components of the base resin or curing agent or the organic solvent used as a reaction medium during the production of the raw materials have not been completely removed and a trace amount of organic solvent remains in the base resin or curing agent, remove the organic solvent. It is understood that it does not substantially contain. On the other hand, solvent-based adhesives are a method in which the adhesive is applied to an object, heated to volatilize the organic solvent in the coating film, and then bonded to another object, the so-called dry lamination method. Refers to the adhesive used. In the case of a two-component curing adhesive, either or both of the main ingredient and the curing agent constituting the adhesive contain an organic solvent. The organic solvent will be described later.

Examples of solvent-free adhesives, ie, non-solvent laminating adhesives, include polyether adhesives, polyester adhesives, silicone adhesives, epoxy adhesives, and urethane adhesives. Among these, urethane adhesives are preferred, and two-component curing type urethane adhesives are more preferred.

In one embodiment, the solvent-free adhesive is a two-component curing adhesive that includes a base agent and a curing agent. The weight average molecular weight (Mw) of the polymer component contained in the base resin is preferably 800 or more and 10,000 or less, more preferably 1,200 or more and 4,000 or less, from the viewpoint of coating suitability. The polydispersity (Mw/Mn) of the polymer component contained in the base agent is preferably 2.8 or less, more preferably 1.2 or more and 2.7 or less, even more preferably 1.5 or more and 2.6 or less, especially Preferably it is 2.0 or more and 2.5 or less. Here, Mn is the number average molecular weight of the polymer component contained in the base resin. Each average molecular weight is measured by gel permeation chromatography (GPC) in accordance with JIS K7252-1 (2008), and is a value in terms of polystyrene.

By forming the adhesive layer using a solvent-free adhesive, for example, the amount of residual solvent in the laminate, specifically the amount of residual organic solvent, can be further reduced. The laminate of the present disclosure includes a resin layer and a stretched base material, each of which contains polyethylene as a main component. Therefore, when producing the laminate of the present disclosure using a solvent-based adhesive, compared to a polyester laminate, it is necessary to lower the drying temperature in order to prevent thermal deterioration and thermal shrinkage of the laminate. desirable. In this case, the solvent in the adhesive may not be sufficiently volatilized and removed and may remain in the laminate, resulting in an odor caused by the residual solvent. By using a solvent-free adhesive, the amount of residual solvent and solvent odor can be further reduced, thermal deterioration and thermal shrinkage of the laminate can be suppressed, and the laminate can be manufactured in a short time.

Examples of the organic solvent include hydrocarbon solvents such as toluene, xylene, n-hexane, and methylcyclohexane; ester solvents such as ethyl acetate, n-propyl acetate, n-butyl acetate, and isobutyl acetate; methanol, ethanol, and isopropyl alcohol. , n-butyl alcohol and isobutyl alcohol; and ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone.

By using a solvent-free adhesive, for example, the adhesive layer can be made thinner than when a solvent-based adhesive is used. Thereby, the content ratio of polyethylene in the entire laminate can be further improved. Such a laminate is suitable for producing a monomaterial packaging container.

The two-component curing urethane adhesive will be described below. As this urethane adhesive, for example, an adhesive having a base agent containing a polyol compound such as a polyester polyol and a curing agent containing an isocyanate compound is preferable.

Examples of polyol compounds include polyester polyols, polyether polyols, polycarbonate polyols, and (meth)acrylic polyols. Among these, polyester polyols are preferred. Polyester polyol has two or more hydroxyl groups in one molecule. A polyester polyol has, for example, a polyester structure or a polyester polyurethane structure as a main skeleton. Polyester polyols can be obtained, for example, by dehydration condensation reaction, transesterification, or ring-opening reaction between a polyhydric alcohol component and a polycarboxylic acid component.

Examples of the polyhydric alcohol component include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6- Diols such as hexanediol, neopentyl glycol and cyclohexanedimethanol; trifunctional or higher functional polyols such as glycerin, triethylolpropane, trimethylolpropane, pentaerythritol and sorbitol.

Examples of the polycarboxylic acid component include aliphatic polycarboxylic acids, alicyclic polycarboxylic acids, aromatic polycarboxylic acids, and ester derivatives and acid anhydrides thereof. Examples of the aliphatic polycarboxylic acids include aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, and dimer acid. Examples of the alicyclic polycarboxylic acids include 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid. Examples of aromatic polycarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, and 1,2-bis(phenoxy)ethane-p , p'-dicarboxylic acid.

The polyester polyol can also be lengthened in advance with polyisocyanate, if necessary. Examples of polyisocyanates include 1,6-hexamethylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, m-xylylene diisocyanate, α, α, α'α'-tetramethyl-m-xylylene diisocyanate, tolylene diisocyanate, and naphthalene. Diisocyanates such as diisocyanates and diphenylmethane diisocyanate; and biuret, nurate or trimethylolpropane adducts of diisocyanates can be mentioned.

From the viewpoint of coating suitability, the weight average molecular weight (Mw) of the polyol compound such as polyester polyol is preferably 800 or more and 10,000 or less, more preferably 1,200 or more and 4,000 or less. The polydispersity (Mw/Mn) of the polyol compound such as polyester polyol is preferably 2.8 or less, more preferably 1.2 or more and 2.7 or less, still more preferably 1.5 or more and 2.6 or less, particularly preferably is 2.0 or more and 2.5 or less. Here, Mn is the number average molecular weight of the polyol compound. Each average molecular weight is measured by gel permeation chromatography (GPC) in accordance with JIS K7252-1 (2008), and is a value in terms of polystyrene.

The isocyanate compound has two or more isocyanate groups in one molecule.
Examples of the isocyanate compound include aromatic isocyanates and aliphatic isocyanates. The isocyanate compound may be a blocked isocyanate compound obtained by addition reaction using a known isocyanate blocking agent by a known and commonly used method.

Examples of the isocyanate compound include tetramethylene diisocyanate, hexamethylene diisocyanate, norbornene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, m-xylylene diisocyanate, hydrogenated xylylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, and α, Diisocyanates such as α,α'α'-tetramethyl-m-xylylene diisocyanate; trimers of these diisocyanates; and these diisocyanate compounds and low-molecular active hydrogen compounds or their alkylene oxide adducts, or polymeric active compounds. Examples include an adduct, a burette, and an allophanate, which are obtained by reacting with a hydrogen compound.

Examples of low-molecular active hydrogen compounds include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, neneopentyl glycol, 1,6-hexamethylene glycol, 1,8-octamethylene glycol, 1,4-Cyclohexane dimethanol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanol Examples of the polymeric active hydrogen compound include amine, diethanolamine, triethanolamine, and metaxylylene diamine, and examples of the polymeric active hydrogen compound include polyester, polyether polyol, and polyamide.

Examples of the adhesive coating method include a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a Fontaine method, and a transfer roll coating method.

In the laminate of the present disclosure, each of the adhesive layers such as the first adhesive layer, the second adhesive layer, and the third adhesive layer has a thickness of 2.0 μm or less, preferably 0.0 μm or less. The thickness is 1 μm or more and 2.0 μm or less, more preferably 0.2 μm or more and 2.0 μm or less, and even more preferably 0.5 μm or more and 2.0 μm or less.

In one embodiment, the amount of residual solvent in the laminate of the present disclosure is preferably 1.5 mg/m ² or less, more preferably 1.0 mg/m ² or less, even more preferably 0.5 mg/m ² or less. The lower limit of the amount of residual solvent is preferably as small as possible, but may be, for example, 0.01 mg/m ² .

The amount of residual solvent can be measured by cutting a 10 cm square sample from the laminate and using, for example, a gas chromatograph GC-2014 manufactured by Shimadzu Corporation by a calibration curve method.

The laminate of the present disclosure can be produced, for example, by laminating a stretched base material or other base material and a film as the first resin layer or second resin layer by a lamination method using the above adhesive, For example, they can be manufactured by bonding together by a non-solvent laminating method using a solvent-free adhesive.

<Structure of laminate>
In one embodiment, the laminate of the present disclosure includes one stretched base material between the first resin layer and the second resin layer, for example, the first resin layer and the first adhesive. layer, a printing substrate, a second adhesive layer, and a second resin layer in this order.

In one embodiment, the laminate of the present disclosure may include two or more stretched base materials between the first resin layer and the second resin layer, for example, a printed base material and a stretched base material. It's okay. In this case, the laminate includes an adhesive layer between each base material. For example, the laminate includes a first resin layer, a first adhesive layer, a printed base material, a second adhesive layer, a stretched base material, a third adhesive layer, and a second adhesive layer. and a resin layer in this order.

In one embodiment, the laminate of the present disclosure includes a coextruded resin described as a second resin layer including a stretched base material and a gas barrier resin layer between the first resin layer and the second resin layer. It may also include other base materials such as films. In this case, the laminate includes an adhesive layer between each base material. For example, the laminate includes a coextruded resin film including a first resin layer, a first adhesive layer, a printing base material, a second adhesive layer, a gas barrier resin layer, and a third resin layer. An adhesive layer and a second resin layer are provided in this order.

Specific examples of the structure of the laminate of the present disclosure will be described below.
・Second resin layer which may include first resin layer/first adhesive layer/printed base material (printed layer/stretched base material)/second adhesive layer/gas barrier resin layer・first Resin layer/first adhesive layer/printed base material (stretched base material/printed layer)/second adhesive layer/second resin layer/first resin layer that may include a gas barrier resin layer /First adhesive layer/Printed base material (printed layer/stretched base material)/Second adhesive layer/Coextruded resin film with gas barrier resin layer/Third adhesive layer/Second resin layer・First resin layer/first adhesive layer/printed base material (stretched base material/printed layer)/second adhesive layer/coextruded resin film with gas barrier resin layer/third adhesive layer /Second resin layer "/" indicates the interlayer between each layer. Printed base material (stretched base material/printed layer) means that the stretched base material faces the first resin layer side and the printed layer faces the second resin layer side. Printed base material (printed layer/stretched base material) means that the stretched base material faces the second resin layer side, and the printed layer faces the first resin layer side.

[Tube container body]
The tube container main body of the present disclosure includes the above-mentioned laminate.
Hereinafter, the tube container main body of the present disclosure will be described with reference to the drawings. FIG. 5 is a diagram schematically showing the configuration of the tube container 20, and FIG. 6 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 5, the tube container main body 21 includes a head portion 22 and a body portion 23, and the body portion 23 is made of the laminate of the present disclosure.

<Head>
The head 22 includes a shoulder 24 connected to one end of the body 23 and an extraction port 25 connected to the shoulder 24. In one embodiment, spout portion 25 includes threads 27 for threading cap 26 .

In one embodiment, the head is constructed from a resin composition containing polyethylene. Thereby, the recyclability of the tube container body can be improved. Examples of polyethylene include high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene and very low density polyethylene. Among these, high-density polyethylene is preferred from the viewpoint of shape retention and moldability. As the polyethylene, biomass polyethylene or mechanically recycled or chemically recycled polyethylene may be used.

The resin composition may contain the additives described above.

The head can be manufactured by a conventionally known method. For example, the head part can be manufactured by a compression molding method or an injection molding method, and can be joined to the body part.

When manufacturing a tube container main body using a compression molding method, the body is attached to a male mold having a convex portion on the upper part, and then the male mold and female mold are made to face each other, and the molten resin composition is A tube container main body including a head and a body can be manufactured by supplying the tube into the male and female, compression molding to form a head, and joining the head to one opening of the body.

When manufacturing tube container bodies using the injection molding method, the body is attached to a male mold with a convex portion on the top, the male mold and female mold are placed opposite each other, and the molten resin is poured through the gate. A tube container main body including a head and a body can be manufactured by supplying a composition, molding the head by injection molding, and joining the head to one opening of the body.

<Torso>
In the tube container main body 21 of the present disclosure, the body 23 is connected to the shoulder 24 of the head 22. The body portion 23 is formed into a cylindrical shape by, for example, stacking the laminate of the present disclosure such that the surface on the first resin layer side at one end and the surface on the second resin layer side at the other end are in contact with each other. A welded portion 28 is formed by heat-sealing the rolled and overlapped portions. The body portion 23 includes a bottom seal portion 29 formed by, for example, heat-sealing the opening of a stacked body rolled into a cylindrical shape.

Examples of heat sealing methods include conventionally known methods such as bar sealing, rotating roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, and flame sealing.

In one embodiment, the laminate of the present disclosure is overlapped so that the first resin layer side surface of one end and the second resin layer side surface of the other end are in contact with each other and rolled into a cylindrical shape, A cylindrical body is manufactured by heat-sealing the overlapped parts. From the viewpoint of heat sealability, it is preferable that one end of the stacked layers is the first resin layer and the other end is the second resin layer. In this case, the first resin layer and the second resin layer are melted and joined to form a welded portion.

In addition, although the welded part is formed by overlapping in the above, the same surfaces of both ends of the laminate may be brought together and the second resin layers may be heat-sealed and joined. In this case, a joining tape may be attached to the outer surface of the trunk so as to cover the joint. The joining tape may be provided on both the inner and outer surfaces of the body.

[Tube container]
Hereinafter, the tube container of the present disclosure will be described with reference to the drawings. As shown in FIG. 5, the tube container 20 of the present disclosure includes a tube container body 21 and a cap 26 attached to the head 22.

<Tube container body>
Since the tube container body has been described above, the description thereof will be omitted here.

<Cap>
The cap is removably attached to the extraction opening of the head and has the role of closing the extraction opening.

In one embodiment, the cap is constructed from a resin composition containing a thermoplastic resin. Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene, polyesters, cellulose resins, and vinyl resins. From the viewpoint of recyclability, polyethylene is particularly preferred. Examples of polyethylene include high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene and very low density polyethylene. Among these, high-density polyethylene is preferred from the viewpoint of shape retention and unsealability. As the polyethylene, biomass polyethylene or mechanically recycled or chemically recycled polyethylene may be used.

The resin composition may contain the additives described above.

As shown in FIG. 5, the cap may be of a screw type having a groove on the inner surface of the cap so as to be screwed into the thread 27 of the extraction port 25. It may be a plugging type that is fitted by plugging.

The present disclosure relates to, for example, the following [1] to [19].
[1] A laminate, the laminate including a first resin layer, a first adhesive layer with a thickness of 2.0 μm or less, a stretched base material, and a second resin layer with a thickness of 2.0 μm or less. and a second resin layer, and the laminate is arranged on a surface of the stretched base material on the first resin layer side and/or on a surface on the second resin layer side. further comprising a design layer, wherein the first resin layer, the stretched base material, and the second resin layer each contain polyethylene as a main component.
[2] The laminate according to [1], wherein the first adhesive layer and the second adhesive layer are each formed of a solvent-free adhesive.
[3] The solvent-free adhesive is a two-component curing adhesive having a base resin and a curing agent, and the weight average molecular weight (Mw) of the polymer component contained in the base resin is 800 or more and 10,000 or more. The laminate according to [2] above, which is as follows.
[4] The solvent-free adhesive is a two-component curing adhesive having a base resin and a curing agent, and the polydispersity (Mw/Mn) of the polymer component contained in the base resin is 2.8. The laminate according to [2] or [3], which is as follows.
[5] The first adhesive layer and the second adhesive layer each have a thickness of 0.5 μm or more and 2.0 μm or less, according to any one of [1] to [4] above. laminate.
[6] The laminate according to any one of [1] to [5], wherein at least one selected from the stretched base material and the second resin layer includes a gas barrier resin layer.
[7] The laminate according to any one of [1] to [6], wherein at least one selected from the stretched base material and the second resin layer includes a polyethylene layer and a gas barrier resin layer.
[8] At least one selected from the stretched base material and the second resin layer includes a first polyethylene layer, a first adhesive resin layer, a gas barrier resin layer, and a second adhesive resin. and a second polyethylene layer, the laminate according to any one of [1] to [7].
[9] The gas barrier resin layer contains a gas barrier resin, and the content ratio of the gas barrier resin in the second resin layer is 1% by mass or more and 30% by mass or less, [6] to [6]. 8].
[10] The above [1], wherein the first resin layer and the second resin layer each independently contain at least one selected from medium density polyethylene, low density polyethylene, and linear low density polyethylene. ] to [9]. The laminate according to any one of [9].
[11] At least one selected from the stretched base material and the second resin layer is a polyethylene film having a total light transmittance of 10% or more and 40% or less (measured according to JIS K7375). The laminate according to any one of [1] to [10].
[12] The stretched base material is a uniaxially stretched polyethylene base material containing at least one selected from medium density polyethylene and high density polyethylene, according to any one of [1] to [11] above. laminate.
[13] The laminate further includes an intermediate base material and a third adhesive layer having a thickness of 2.0 μm or less between the second adhesive layer and the second resin layer, The laminate according to any one of [1] to [12] above, wherein the intermediate base material includes a polyethylene layer and a gas barrier resin layer.
[14] The laminate according to any one of [1] to [13], wherein the content of polyethylene in the entire laminate is 90% by mass or more.
[15] A laminate for forming the body of a tube container main body, wherein the first resin layer is a sealant layer on the outer surface of the body, and the second resin layer is a sealant layer on the inner surface of the body. The laminate according to any one of [1] to [14] above, which is a layer.
[16] A tube container main body comprising a head and a body, the head comprising a shoulder connected to one end of the body and an extraction opening connected to the shoulder, A tube container main body, the part of which is composed of the laminate according to any one of [1] to [15].
[17] The tube container main body according to [16], wherein the head portion is made of a resin composition containing polyethylene.
[18] A tube container comprising the tube container main body according to [16] or [17] above, and a cap.
[19] The tube container according to [18], wherein the cap is made of a resin composition containing polyethylene.

Hereinafter, the laminate of the present disclosure will be explained more specifically using Examples, but the laminate of the present disclosure is not limited to the following Examples.

[Preparation of stretched base material]
The polyethylene used for producing the stretched base material will be described below.
・Medium density polyethylene (hereinafter referred to as "MDPE"):
Product name Enable4002MC
Density: 0.940g/cm ³ , Melting point: 128°C, MFR: 0.25g/10min,
High-density polyethylene (1) manufactured by ExxonMobil (hereinafter referred to as "HDPE (1)"):
Product name Elite5960G
Density: 0.960g/cm ³ , Melting point: 134°C, MFR: 0.8g/10min,
High-density polyethylene (2) manufactured by Dow Chemical (hereinafter referred to as "HDPE (2)"):
Product name H619F
Density: 0.965g/cm ³ , Melting point: 135°C, MFR: 0.7g/10min,
Linear low-density polyethylene (hereinafter referred to as "LLDPE") manufactured by SCG:
Product name: Exceed XP8656ML
Density: 0.916g/cm ³ , Melting point: 121°C, MFR: 0.5g/10min,
Low-density polyethylene (hereinafter referred to as "LDPE") manufactured by ExxonMobil:
Product name LD2420F
Density: 0.922g/cm ³ , Melting point: 112°C, MFR: 0.75g/10min,
MB manufactured by PTT and containing slip agent:
Product name SLIP61 10061-K
Density: 0.910g/cm ³ , MFR: 10g/10min,
Polyethylene base, containing 5% by mass of erucic acid amide slip agent,
Manufactured by Ampacet

Blend polyethylene A1 (hereinafter referred to as "blend PE (A1)") was obtained by mixing 70 parts of MDPE and 30 parts of HDPE (1). Blend polyethylene B1 (hereinafter referred to as "blend PE (B1)") was obtained by mixing 70 parts of HDPE (2) and 30 parts of LDPE. Blend polyethylene C1 (hereinafter referred to as "blend PE (C1)") was obtained by mixing 98 parts of LLDPE and 2 parts of MB containing a slip agent.

Blend PE (A1), blend PE (B1) and blend PE (C1) were formed into blend PE (A1) layer (15 μm)/blend PE (B1) layer (22.5 μm)/blend PE (C1) by an inflation molding method. ) layer (50 μm) / Blend PE (B1) layer (22.5 μm) / Blend PE (A1) layer (15 μm) Co-extrusion of 5 layers was performed to form a tube-shaped film with a total thickness of 125 μm. A polyethylene film was obtained, and the tube-shaped film was folded at the nip point to form two layers. Numbers in parentheses indicate layer thickness. The polyethylene film produced above was stretched in the longitudinal direction (MD) at a stretching ratio of 5 times, and the blended PE (A1) layer (surface layer) on one side was subjected to corona discharge treatment, and then the edges were It was slit and divided into two pieces.

As described above, a uniaxially stretched polyethylene multilayer base material having a thickness of 25 μm was obtained. The haze of the stretched multilayer base material was measured in accordance with JIS K7136 and was found to be 5.6%.

[Production of EVOH-containing polyethylene film]
Linear low-density polyethylene (manufactured by Dow Chemical, DOWLEX2045G, density 0.920 g/cm ³ ), adhesive resin (manufactured by Mitsui Chemicals, Admer NF557), ethylene-vinyl alcohol copolymer (manufactured by Kuraray, EVAL H171B, (density: 1.17 g/cm ³ , ethylene content: 38 mol%), adhesive resin (manufactured by Mitsui Chemicals, Admer NF557), linear low-density polyethylene (manufactured by Dow Chemical, DOWLEX2045G, density: 0.920 g/cm ³ ) A five-layer coextrusion film was formed using the inflation method to obtain an EVOH-containing polyethylene film having a thickness of 100 μm or 75 μm. In this film, the thickness of the ethylene-vinyl alcohol copolymer layer was about 10%, and the thickness of the linear low-density polyethylene layer was about 40% of the total film thickness.

[Polyethylene film]
The following polyethylene film was used.
- Antistatic agent-containing polyethylene film 1 with a thickness of 150 μm (formed from a mixture of polyethylene (density: 0.931 g/cm ³ , MFR: 2.1 g/10 minutes) and antistatic agent)
- Polyethylene film 2 with a thickness of 100 μm (made of a mixture of polyethylene (density: 0.931 g/cm ³ , MFR: 2.1 g/10 minutes) and white pigment, milky white type, total light transmittance: about 15%)
- Antistatic agent-containing polyethylene film 3 with a thickness of 130 μm (formed from a mixture of polyethylene (density: 0.920 g/cm ³ , MFR: 1.9 g/10 minutes) and antistatic agent)
- Polyethylene film 4 with a thickness of 130 μm (made of a mixture of polyethylene (density: 0.920 g/cm ³ , MFR: 1.9 g/10 min) and white pigment, milky white type, total light transmittance: about 15%)

[Example 1]
The above-mentioned uniaxially stretched polyethylene multilayer base material was used as the stretched base material. Urethane-based gravure ink (NEW-LP Super, manufactured by Toyo Ink) was applied onto the stretched substrate by gravure printing and dried to form a 1 μm thick printed layer. In this way, a printing base material was obtained.

Each layer was laminated onto the printed substrate using a single non-solvent laminating machine. Specifically, a urethane-based two-component curing adhesive (manufactured by Rock Paint, solvent-free adhesive, main agent: RN-920, curing agent: HN-920) is applied to the printing layer forming surface of the printing base material. Then, an adhesive layer with a thickness of 1.5 μm was formed, and an EVOH-containing polyethylene film with a thickness of 100 μm was laminated on this adhesive layer. Next, the above-mentioned urethane-based two-component curing adhesive (base material: RN-920, curing agent: HN-920) is applied to the surface of the printing substrate opposite to the surface on which the printing layer is formed, to a thickness of 1. An adhesive layer having a thickness of .5 μm was formed, and an antistatic agent-containing polyethylene film 1 having a thickness of 150 μm was laminated on this adhesive layer. A laminate was obtained in the manner described above.

The weight average molecular weight (Mw) of the polymer component contained in the main material in the above solvent-free adhesive is in the range of 2,000 to 2,500, and the polydispersity (Mw/Mn) of the polymer component contained in the main material is in the range of 2,000 to 2,500. ranged from 2.0 to 2.5.

The laminate includes (outermost layer) an antistatic agent-containing polyethylene film 1 (150 μm), an adhesive layer (1.5 μm), a uniaxially stretched polyethylene multilayer base material (25 μm), a printed layer (1 μm), and an adhesive layer (1.5 μm). 5 μm) and an EVOH-containing polyethylene film (100 μm) (innermost layer).

[Example 2]
A 25 μm thick uniaxially stretched high-density polyethylene film (manufactured by Tokyo Ink, Hybron SMKQW, Opalescent Grade) was used as the stretched base material constituting the printing base material, and the printed base material was oriented so that the stretched base material faced the EVOH-containing polyethylene film side. A laminate was obtained in the same manner as in Example 1 except that .

The laminate includes (outermost layer) antistatic agent-containing polyethylene film 1 (150 μm), adhesive layer (1.5 μm), printing layer (1 μm), uniaxially stretched high-density polyethylene film (Hybron SMKQW, 25 μm), adhesive layer (1.5 μm) and an EVOH-containing polyethylene film (100 μm) (innermost layer).

[Example 3]
The above-mentioned uniaxially stretched polyethylene multilayer base material was used as the stretched base material. Urethane-based gravure ink (NEW-LP Super, manufactured by Toyo Ink) was applied onto the stretched substrate by gravure printing and dried to form a 1 μm thick printed layer. In this way, a printing base material was obtained.

Each layer was laminated onto the printed substrate using a single non-solvent laminating machine. Specifically, the above-mentioned urethane-based two-component curable adhesive (base material: RN-920, curing agent: HN-920) was applied to the surface of the printing base material on which the printing layer was to be formed, and a 1.5 μm thick adhesive was formed. An EVOH-containing polyethylene film having a thickness of 75 μm was laminated on the adhesive layer. Next, the above-mentioned urethane-based two-component curing adhesive (base material: RN-920, curing agent: HN-920) is applied to the surface of the printing substrate opposite to the surface on which the printing layer is formed, to a thickness of 1. An adhesive layer having a thickness of .5 μm was formed, and an antistatic agent-containing polyethylene film 1 having a thickness of 150 μm was laminated on this adhesive layer. Next, the above urethane-based two-component curing adhesive (base resin: RN-920, curing agent: HN-920) was applied to the surface of the EVOH-containing polyethylene film to form an adhesive layer with a thickness of 1.5 μm. A polyethylene film 2 (opalescent type) having a thickness of 100 μm was laminated on this adhesive layer. A laminate was obtained in the manner described above.

The laminate includes (outermost layer) an antistatic agent-containing polyethylene film 1 (150 μm), an adhesive layer (1.5 μm), a uniaxially stretched polyethylene multilayer base material (25 μm), a printed layer (1 μm), and an adhesive layer (1.5 μm). 5 μm), an EVOH-containing polyethylene film (75 μm), an adhesive layer (1.5 μm), and a polyethylene film 2 (opalescent type, 100 μm) (innermost layer).

[Example 4]
A 25 μm thick uniaxially stretched high-density polyethylene film (manufactured by Tokyo Ink, Hybron SMKQW, Opalescent Grade) was used as the stretched base material constituting the printing base material, and the printed base material was oriented so that the stretched base material faced the EVOH-containing polyethylene film side. A laminate was obtained in the same manner as in Example 3 except that .

The laminate includes (outermost layer) antistatic agent-containing polyethylene film 1 (150 μm), adhesive layer (1.5 μm), printing layer (1 μm), uniaxially stretched high-density polyethylene film (Hybron SMKQW, 25 μm), adhesive layer (1.5 μm), an EVOH-containing polyethylene film (75 μm), an adhesive layer (1.5 μm), and a polyethylene film 2 (opalescent type, 100 μm) (innermost layer).

[Comparative example 1]
Using a urethane-based two-component curing adhesive (manufactured by Rock Paint, solvent-based adhesive, main agent: RU-80, curing agent: H-5) as the adhesive, it was applied with a single dry laminating machine, dried and thickened. A laminate was obtained in the same manner as in Example 1 except that a 3.0 μm adhesive layer was formed and each layer was laminated.

The weight average molecular weight (Mw) of the polymer component contained in the main ingredient in the above solvent-based adhesive is in the range of 30,000 to 34,000, and the number average molecular weight (Mn) is in the range of 7,500 to 9,500. there were.

The laminate includes (outermost layer) an antistatic agent-containing polyethylene film 1 (150 μm), an adhesive layer (3.0 μm), a uniaxially oriented polyethylene multilayer base material (25 μm), a printed layer (1 μm), an adhesive layer (3.0 μm), and an adhesive layer (3.0 μm). 0 μm) and an EVOH-containing polyethylene film (100 μm) (innermost layer).

[Comparative example 2]
Using a urethane-based two-component curing adhesive (manufactured by Rock Paint, solvent-based adhesive, main agent: RU-80, curing agent: H-5) as the adhesive, it was applied with a single dry laminating machine, dried and thickened. A laminate was obtained in the same manner as in Example 2 except that a 3.0 μm adhesive layer was formed and each layer was laminated.

The laminate includes (outermost layer) antistatic agent-containing polyethylene film 1 (150 μm), adhesive layer (3.0 μm), printing layer (1 μm), uniaxially stretched high-density polyethylene film (Hybron SMKQW, 25 μm), adhesive layer (3.0 μm) and an EVOH-containing polyethylene film (100 μm) (innermost layer).

[Comparative example 3]
As a base material, a vapor-deposited film (IB-PET-WUB, manufactured by Dainippon Printing Co., Ltd.) in which a vapor-deposited film was formed on a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm was used. Urethane-based gravure ink (NEW-LP Super, manufactured by Toyo Ink) was applied onto the vapor deposited film of the base material by gravure printing and dried to form a printed layer with a thickness of 1 μm. In this way, a printing base material was obtained.

Each layer was laminated onto the printing substrate using a tandem dry laminator. Specifically, a urethane-based two-component curing adhesive (manufactured by Rock Paint, solvent-based adhesive, main agent: RU-004, curing agent: H-1) is applied to the printing layer forming surface of the printing base material, It was dried to form an adhesive layer with a thickness of 3.0 μm, and a polyethylene film 4 (opalescent type) with a thickness of 130 μm was laminated on this adhesive layer. Next, the above-mentioned urethane-based two-component curable adhesive (base material: RU-004, curing agent: H-1) is applied to the surface of the printing substrate opposite to the surface on which the printing layer is formed, dried, and thickened. An adhesive layer with a thickness of 3.0 μm was formed, and an antistatic agent-containing polyethylene film 3 with a thickness of 130 μm was laminated on this adhesive layer. A laminate was obtained in the manner described above.

The weight average molecular weight (Mw) of the polymer component contained in the main ingredient in the above solvent-based adhesive is in the range of 28,000 to 32,000, and the number average molecular weight (Mn) is in the range of 7,000 to 9,000. there were.

The laminate includes (outermost layer) an antistatic agent-containing polyethylene film 3 (130 μm), an adhesive layer (3.0 μm), a vapor-deposited film (IB-PET-WUB, 12 μm), a printed layer (1 μm), an adhesive layer ( 3.0 μm) and a polyethylene film 4 (opalescent type, 130 μm) (innermost layer).

[Preparation of tube container]
The laminates obtained in Examples and Comparative Examples were processed into individual laminate pieces with a width of 157.3 mm using a bobbin cutter, and both ends in the width direction were stacked so that the overlap width was about 1.2 mm. After combining, the overlapped ends were heat-sealed under the conditions of 0.1 MPa, 120° C., and 1.0 seconds to obtain a cylindrical original fabric with a tube attached. The obtained original fabric was cut to a length of 184.2 mm to produce a cylindrical body that would become the body of the tube container. The cylindrical body is attached to a mandrel for forming tube containers, and a head consisting of a truncated conical shoulder and an extraction opening on the cylinder that is continuous with the shoulder is attached to one end of the cylindrical body. Density polyethylene (Suntech J345 manufactured by Asahi Kasei Co., Ltd., density 0.956 g/cm ³ ) was molded by compression molding to produce a tube container body as shown in FIG. 5. The spout at the head of the resulting tube container body had an outer diameter of 30.4 mm and a height of 9.5 mm, and a thread was provided on the side surface of the spout. Further, the outer diameter of the shoulder portion is 50 mm. Next, the above-mentioned high-density polyethylene was injected into a mold for molding a cap and molded to produce a cap. A tube container was obtained as described above.

[Evaluation of the physical properties]
<Evaluation of physical properties of tube containers (seal strength)>
(Side seam strength)
The body of the tube container was cut into a strip with a width of 15 mm in a direction perpendicular to the side seam (tube pasting location) to obtain a test piece. In accordance with JIS K6854-2, this test piece was pulled at a test speed of 300 mm/min using a tensile tester (manufactured by Orientec, STA-1150), and the strength at which the test piece broke (side seam strength) was measured. It was measured.
(Shoulder adhesion strength)
A test piece was obtained by cutting the tube container at two locations where the body and the shoulder were bonded, the tube pasting location and the location 180° opposite thereof, into a strip with a width of 15 mm in the direction of the hem. This test piece was pulled at a test speed of 300 mm/min using a tensile tester (manufactured by Orientec, STA-1150) to measure the peel strength when the body part was peeled off from the shoulder part.

<Check for residual solvent>
The total amount (mg/m ² ) of toluene, ethyl acetate, isopropyl alcohol, methanol, and methyl ethyl ketone contained in the laminates obtained in Examples and Comparative Examples was measured by gas chromatography. Specifically, the amount of residual solvent was measured by cutting a 10 cm square sample from the laminate and using a gas chromatograph GC-2014 manufactured by Shimadzu Corporation by a calibration curve method.

<Loop evaluation>
A product name "LOOP STIFFNESS TESTER" manufactured by Toyo Seiki Co., Ltd. was used as a measuring device. The laminates obtained in Examples and Comparative Examples were each cut into a size of 15 mm in width and 100 mm in length (flow direction during film formation: MD, direction perpendicular to the flow direction during film formation: TD). , was used as the measurement sample. Next, both ends of the measurement sample were fixed between clips so that the innermost layer of the measurement sample was on the inside, and a circular loop having a loop length of 70 mm was formed at the center portion in the length direction. The obtained circular loop was pushed in from the opposite side of the clip at a pushing speed of 3.3 mm/sec, and the load required to reach a load range of 5000 mN was defined as the loop stiffness value.

<Heat shrinkage rate>
Using the printing base material and the laminate after lamination, check the heat shrinkage in the width direction (TD) and machine direction (MD) before and after lamination using a glass scale measurement standard standard scale HL3 (Mitutoyo). did.

<Pressure test>
The tube container was filled with 180 g of Lux Super Rich Treatment (manufactured by Unilever Japan), and a load of 60 kgf was applied for 1 minute to check for leakage of the contents from the tube container.

<Monomaterial>
The content ratio of polyethylene (monomaterial ratio) was calculated from the specific gravity of the material constituting each layer of the laminate obtained in Examples and Comparative Examples and the thickness of each layer. Furthermore, the laminates obtained in Examples and Comparative Examples were determined to be monomaterials in accordance with the CEFLEX guidelines. The evaluation was rated as “〇” if it met the CEFLEX guidelines, and “x” if it did not.

1: Laminate 2: First resin layer 4: Stretched base material 4a: Design layer 6: Second resin layer 7: Other base material 8A: First adhesive layer 8B: Second adhesive layer 8C : Third adhesive layer 20: Tube container 21: Tube container main body 22: Head 23: Body 24: Shoulder 25: Extraction opening 26: Cap 27: Thread 28: Welded part 29: Bottom seal part

Claims (19)

A laminate,
The laminate is
a first resin layer;
a first adhesive layer with a thickness of 2.0 μm or less;
A stretched base material;
a second adhesive layer with a thickness of 2.0 μm or less;
a second resin layer;
comprising at least
The laminate further includes a design layer on the first resin layer side surface and/or the second resin layer side surface of the stretched base material,
The first resin layer, the stretched base material and the second resin layer each contain polyethylene as a main component,
laminate. The laminate according to claim 1, wherein the first adhesive layer and the second adhesive layer are each formed of a solvent-free adhesive. The solvent-free adhesive is a two-component curing adhesive having a base resin and a curing agent, and the weight average molecular weight (Mw) of the polymer component contained in the base resin is 800 or more and 10,000 or less. , The laminate according to claim 2. The solvent-free adhesive is a two-component curing adhesive having a base resin and a curing agent, and the polydispersity (Mw/Mn) of the polymer component contained in the base resin is 2.8 or less. , The laminate according to claim 2 or 3. The laminate according to any one of claims 1 to 4, wherein the first adhesive layer and the second adhesive layer each have a thickness of 0.5 μm or more and 2.0 μm or less. The laminate according to any one of claims 1 to 5, wherein at least one selected from the stretched base material and the second resin layer includes a gas barrier resin layer. The laminate according to any one of claims 1 to 6, wherein at least one selected from the stretched base material and the second resin layer comprises a polyethylene layer and a gas barrier resin layer. At least one selected from the stretched base material and the second resin layer is a first polyethylene layer, a first adhesive resin layer, a gas barrier resin layer, a second adhesive resin layer, The laminate according to any one of claims 1 to 7, comprising a second polyethylene layer. Any one of claims 6 to 8, wherein the gas barrier resin layer contains a gas barrier resin, and the content ratio of the gas barrier resin in the second resin layer is 1% by mass or more and 30% by mass or less. The laminate described in section. The first resin layer and the second resin layer each independently contain at least one selected from medium density polyethylene, low density polyethylene and linear low density polyethylene. The laminate according to any one of the items. At least one selected from the stretched base material and the second resin layer is a polyethylene film having a total light transmittance (measured according to JIS K7375) of 10% or more and 40% or less. 11. The laminate according to any one of 10. The laminate according to any one of claims 1 to 11, wherein the stretched base material is a uniaxially stretched polyethylene base material containing at least one selected from medium density polyethylene and high density polyethylene. The laminate further includes an intermediate base material and a third adhesive layer having a thickness of 2.0 μm or less between the second adhesive layer and the second resin layer, and the intermediate base material The laminate according to any one of claims 1 to 12, wherein the laminate comprises a polyethylene layer and a gas barrier resin layer. The laminate according to any one of claims 1 to 13, wherein the content of polyethylene in the entire laminate is 90% by mass or more. A laminate for forming a body of a tube container main body, wherein the first resin layer is a sealant layer on the outer surface of the body, and the second resin layer is a sealant layer on the inner surface of the body. , the laminate according to any one of claims 1 to 14. A tube container body comprising a head and a body,
The head portion includes a shoulder portion connected to one end of the body portion, and an extraction port portion connected to the shoulder portion, and the body portion is the laminate body according to any one of claims 1 to 15. Consisting of
Tube container body. The tube container main body according to claim 16, wherein the head portion is made of a resin composition containing polyethylene. The tube container main body according to claim 16 or 17;
A tube container comprising a cap. The tube container according to claim 18, wherein the cap is made of a resin composition containing polyethylene.

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