JP2023149114A - Rigid base material, printing base material, laminate and packaging bag - Google Patents

Abstract

To provide a rigid base material which is useful as a base material in a packaging material for manufacturing a packaging bag excellent in recyclability and rigidity.SOLUTION: A rigid base material includes at least a polyolefin layer containing polyolefin as a main component, and a hetero atom-containing resin layer containing a hetero atom-containing resin as a main component, and is subjected to stretching treatment.SELECTED DRAWING: None

Description

The present disclosure relates to rigid substrates, printed substrates, laminates, and packaging bags.

Packaging bags are used to contain fluid contents such as liquids and powders. The packaging bag is composed of a laminate including a base material and a sealant layer. For example, polyolefin films are widely used as sealant layers because they have flexibility and transparency and have excellent heat sealability. Furthermore, stretched polyester films or stretched polyamide films are widely used as base materials because of their excellent strength and heat resistance.

In recent years, there has been a demand for recycling packaging bags from the perspective of reducing environmental impact. From the viewpoint of recycling, it is preferable that the base material and the sealant layer are each made of the same type of resin material (monomaterialization). For example, Patent Document 1 proposes that the base material and the sealant layer are made of polyethylene.

JP2020-55156A

The present inventors have considered producing a packaging bag using a laminate including a stretched polyolefin film as a packaging material instead of a stretched polyester film and a stretched polyamide film as a base material. However, such packaging bags do not have sufficient rigidity and tend to be insufficiently self-supporting.

One object of the present disclosure is to provide a rigid base material useful as a base material in a packaging material for producing a packaging bag with excellent recyclability and rigidity.

The rigid base material of the present disclosure includes at least a polyolefin layer containing a polyolefin as a main component and a heteroatom-containing resin layer containing a heteroatom-containing resin as a main component, and is subjected to a stretching treatment.

According to the present disclosure, it is possible to provide a rigid base material useful as a base material in a packaging material for producing a packaging bag with excellent recyclability and rigidity.

FIG. 1 is a schematic cross-sectional view showing one embodiment of a rigid base material. FIG. 2 is a schematic cross-sectional view showing one embodiment of a rigid base material. FIG. 3 is a schematic cross-sectional view showing one embodiment of a rigid base material. FIG. 4 is a schematic cross-sectional view showing one embodiment of the laminate. FIG. 5 is a front view showing one embodiment of the packaging bag. FIG. 6 is a front view showing one embodiment of the packaging bag. FIG. 7 is a front view showing one embodiment of a packaging bag. FIG. 8 is a front view showing one embodiment of the packaging bag.

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 clearer, 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.

In the following description, each component that appears (for example, polyolefins such as polyethylene and polypropylene, α-olefins, resin materials such as heteroatom-containing resins and adhesive resins, and additives) may be used alone, Two or more types may be used.
"Main component" means a component contained in a layer or base material in an amount of 50% by mass or more.

[Rigid base material]
The rigid substrate of the present disclosure includes:
a polyolefin layer;
and a heteroatom-containing resin layer.

The polyolefin layer contains polyolefin as a main component. In the present disclosure, the term "polyolefin layer" refers to a layer containing polyolefin such as polyethylene and polypropylene as a main component.
The heteroatom-containing resin layer contains a heteroatom-containing resin as a main component.
The rigid base material has been subjected to a stretching process.

The rigid base material may include, for example, a polyolefin layer, an adhesive resin layer, a heteroatom-containing resin layer, an adhesive resin layer, and a polyolefin layer in this order, or a polyolefin layer, an adhesive resin layer, and a polyolefin layer. , and a heteroatom-containing resin layer may be provided in this order. Each layer such as a polyolefin layer may be present in two or more layers.

The polyolefin content in the rigid base material is preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more. Thereby, for example, the recyclability of the packaging bag can be improved.

The rigid base material is a base material that has been subjected to a stretching process. Thereby, for example, the strength, heat resistance, and transparency of the base material can be improved. The stretching treatment may be uniaxial stretching or biaxial stretching. The stretching ratio when stretching in the longitudinal direction (the flow direction of the base material, MD) may be 2 times or more, 3 times or more, 10 times or less, or 7 times or less. The stretching ratio when stretching in the transverse direction (direction perpendicular to MD, TD) may be 2 times or more, 3 times or more, 10 times or less, or 7 times or less.
The rigid base material is, for example, a base material uniaxially stretched in the MD.

The thickness of the rigid base material is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 15 μm or more, and preferably 200 μm or less, more preferably 100 μm or less, and still more preferably 50 μm or less. When the thickness is at least the lower limit, for example, the strength and heat resistance of the rigid base material can be improved. When the thickness is below the upper limit, for example, the processing suitability of the rigid base material can be improved.

The rigid base material can be produced, for example, by forming a film from a resin composition constituting each layer by an inflation molding method, a T-die molding method, or the like, and then stretching the film. According to the inflation molding method, film formation and stretching can be performed simultaneously.

The rigid substrate, in one embodiment, is a coextruded resin film.
In one embodiment, the rigid base material includes a material constituting the polyolefin layer, a material constituting the adhesive resin layer when the rigid base material includes an adhesive resin layer, and a material constituting the heteroatom-containing resin layer. This is a resin film obtained by coextrusion film-forming using a coextrusion inflation method and further stretching treatment.

The rigid base material may be surface-treated. Thereby, for example, the adhesion between the rigid base material and other layers can be improved. Examples of surface treatment methods include physical treatments such as corona treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and/or nitrogen gas, and glow discharge treatment; and chemical treatments such as oxidation treatment using chemicals. For example,

<Layer structure of rigid base material>
Hereinafter, several examples will be given regarding the layer structure of the rigid base material of the present disclosure.
A rigid base material 1 shown in FIG. 1 includes a polyolefin layer 2 and a heteroatom-containing resin layer 4. The rigid base material 1 shown in FIG. 2 includes a polyolefin layer 2, a polyolefin layer 2, a polyolefin layer 2, an adhesive resin layer 3, and a heteroatom-containing resin layer 4 in this order. The rigid base material 1 shown in FIG. 3 includes a polyolefin layer 2, an adhesive resin layer 3, a heteroatom-containing resin layer 4, an adhesive resin layer 3, and a polyolefin layer 2 in this order.

<Polyolefin layer>
The polyolefin layer contains polyolefin as a main component. Examples of polyolefins include polyethylene, polypropylene, and polymethylpentene. As the polyolefin layer, a polyethylene layer and a polypropylene layer are preferable, and a polyethylene layer is more preferable.

The melt flow rate (MFR) of the polyolefin is preferably 0.1 g/10 minutes or more, more preferably 0.2 g/10 minutes or more, and even more preferably 0.5 g/10 minutes from the viewpoint of film formability and processing suitability. or more, preferably 50 g/10 minutes or less, more preferably 30 g/10 minutes or less, even more preferably 10 g/10 minutes or less, particularly preferably 5.0 g/10 minutes or less. The MFR of polyolefin is measured by method A in accordance with JIS K7210 under the condition of a load of 2.16 kg. The measurement temperature for MFR is set depending on the melting point of the polyolefin, and is, for example, 190°C in the case of polyethylene and 230°C in the case of polypropylene.

The content of polyolefin in the polyolefin layer is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, particularly preferably 90% by mass or more or 95% by mass or more.

The polyolefin layer may contain resin materials other than polyolefin. Examples of such resin materials include (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins.

The polyolefin layer may contain additives. Examples of additives include crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, compatibilizers, pigments, and modifying resins. Can be mentioned.

The thickness of the polyolefin layer is preferably 5 μm or more, more preferably 10 μm or more, and preferably 100 μm or less, more preferably 50 μm or less. When the thickness is at least the lower limit, the strength, heat resistance, and recyclability of the base material can be improved, for example. When the thickness is below the upper limit, for example, the processing suitability of the base material can be improved. When the rigid base material includes two or more polyolefin layers, the above "thickness" means the total thickness of each polyolefin layer.

The rigid base material may include one polyolefin layer, or may include two or more polyolefin layers.

(Polyethylene layer)
The polyethylene layer contains polyethylene as a main component.
In the present disclosure, polyethylene refers to a polymer in which the content of ethylene-derived structural units is 50 mol% or more among all repeating structural units. In this polymer, the content of the structural unit derived from ethylene is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, particularly preferably 95 mol% or more. The above content ratio can be measured by NMR method.

In the present disclosure, polyethylene may be a homopolymer of ethylene or a copolymer of ethylene and an ethylenically unsaturated monomer other than ethylene. Examples of ethylenically unsaturated monomers other than ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene. , 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, and 6-methyl-1-heptene, and other α-olefins having 2 to 20 carbon atoms; vinyl such as vinyl acetate and vinyl propionate. Monomers; and (meth)acrylic esters such as methyl (meth)acrylate and ethyl (meth)acrylate.

In the present disclosure, polyethylene includes, for example, high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, and very low density polyethylene. From the viewpoint of the strength and heat resistance of the rigid base material, high-density polyethylene and medium-density polyethylene are preferred. From the viewpoint of film formability and processability of the rigid base material, linear low-density polyethylene and medium-density polyethylene are preferred. Particularly preferred is medium density polyethylene. As the polyethylene, from the viewpoint of reducing environmental load, biomass-derived polyethylene, mechanically recycled or chemically recycled polyethylene may be used.

In the present disclosure, the density of polyethylene is as follows.
The density of the high density polyethylene is preferably greater than 0.945 g/cm ³ . The upper limit of the density of high-density polyethylene is, for example, 0.965 g/cm ³ . The density of the medium density polyethylene is preferably greater than 0.930 g/cm ³ and less than 0.945 g/cm ³ . The density of the low density polyethylene is preferably greater than 0.900 g/cm ³ and less than 0.930 g/cm ³ . The density of the linear low density polyethylene is preferably more than 0.900 g/cm ³ and less than 0.930 g/cm ³ . The density of the ultra-low density polyethylene is preferably 0.900 g/cm ³ or less. The lower limit of the density of ultra-low density polyethylene is, for example, 0.860 g/cm ³ . The density of polyethylene is measured in accordance with JIS K7112 (particularly 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 polymerization method using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as 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.
The above description of polyethylene can also be applied elsewhere.

From the viewpoint of heat resistance, the melting point (Tm) of polyethylene is preferably 100°C or higher, more preferably 105°C or higher, even more preferably 110°C or higher, particularly preferably 120°C or higher, and preferably 140°C or lower. . Tm is the melting peak temperature obtained by differential scanning calorimetry (DSC) according to JIS K7121.

The content of polyethylene in the polyethylene layer is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, particularly preferably 90% by mass or more or 95% by mass or more.

(Polypropylene layer)
The polypropylene layer contains polypropylene as a main component. By providing the rigid base material with a polypropylene layer, for example, the oil resistance of a packaging bag produced using the rigid base material can be improved.

The polypropylene may be any of a propylene homopolymer (homopolypropylene), a propylene random copolymer (random polypropylene), and a propylene block copolymer (block polypropylene), or a mixture of two or more selected from these. As the polypropylene, from the viewpoint of reducing environmental load, biomass-derived polypropylene, mechanically recycled or chemically recycled polypropylene may be used.

A propylene homopolymer is a polymer of only propylene. A propylene random copolymer is a random copolymer of propylene and an α-olefin other than propylene. A propylene block copolymer is a copolymer having at least a polymer block made of propylene and a polymer block made of at least an α-olefin other than propylene.

Examples of α-olefins other than propylene include α-olefins having 2 to 20 carbon atoms, specifically ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1- Mention may be made of decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene and 6-methyl-1-heptene.

Among polypropylenes, propylene random copolymers are preferred from the viewpoint of transparency. When the rigidity and heat resistance of the packaging bag are important, propylene homopolymer is preferred. If the impact resistance of the packaging bag is important, propylene block copolymers are preferred.

The density of polypropylene is, for example, 0.88 g/cm ³ or more and 0.92 g/cm ³ or less. The density of polypropylene is measured in accordance with JIS K7112 (especially D method (density gradient tube method, 23° C.)).

From the viewpoint of heat resistance, the melting point (Tm) of polypropylene is preferably 120°C or higher, more preferably 130°C or higher, even more preferably 150°C or higher, and preferably 170°C or lower. Tm is the melting peak temperature obtained by differential scanning calorimetry (DSC) according to JIS K7121.

The content of polypropylene in the polypropylene layer is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, particularly preferably 90% by mass or more or 95% by mass or more.

<Hetero atom-containing resin layer>
The rigid base material of the present disclosure includes a heteroatom-containing resin layer containing a heteroatom-containing resin as a main component. For example, in a laminate that includes at least a stretched base material and a sealant layer, the rigid base material is used as the stretched base material, and a layer containing polyolefin as a main component is used as the sealant layer, so that a packaging bag including the laminate can be used. The recyclability and rigidity of the material can be improved, and the impact resistance can also be improved. Therefore, a standing pouch equipped with such a rigid base material has excellent self-supporting properties.

Since the rigid base material of the present disclosure includes the heteroatom-containing resin layer, in one embodiment, it has excellent heat resistance compared to conventional polyolefin stretched base materials. Therefore, a laminate including the rigid base material has excellent bag-forming properties and filling properties compared to a laminate including a conventional polyolefin stretched base material. For example, the heating temperature during heat-sealing in the bag-making process and filling process can be increased, and heat-sealing can be performed at high temperatures and in a short time, so productivity of packaging bags can be improved.

Since the rigid base material of the present disclosure includes the above-described heteroatom-containing resin layer, in one embodiment, it has excellent fragrance retention and gas barrier properties (particularly oxygen barrier properties) as compared to conventional polyolefin stretched base materials. Therefore, a packaging bag including such a rigid base material has excellent fragrance retention and gas barrier properties.

Since the rigid base material of the present disclosure includes the heteroatom-containing resin layer, in one embodiment, the rigid base material of the present disclosure has excellent tearability compared to conventional polyolefin stretched base materials. Therefore, a packaging bag including such a rigid base material has excellent unsealability.

Since the rigid base material of the present disclosure includes the above heteroatom-containing resin layer, in one embodiment, it has excellent puncture resistance compared to conventional polyolefin stretched base materials. Therefore, a packaging bag provided with such a rigid base material has excellent filling properties with hard contents.

Examples of the heteroatoms in the heteroatom-containing resin include oxygen atoms, sulfur atoms, nitrogen atoms, and chlorine atoms. The heteroatom-containing resin has heteroatom-containing groups such as, for example, hydroxy groups and amide groups. Examples of the heteroatom-containing resin include ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyamide, polyvinylidene chloride, polyether polyol, and polyester polyol. Among these, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, and polyamides are preferred from the viewpoints of rigidity, fragrance retention, gas barrier properties (especially oxygen barrier properties), heat resistance, tear resistance, puncture resistance, and impact resistance. are preferred, ethylene-vinyl alcohol copolymers and polyamides are more preferred, and ethylene-vinyl alcohol copolymers are even more preferred from the viewpoint of rigidity.

Ethylene-vinyl alcohol copolymer (EVOH) can be obtained, for example, by copolymerizing ethylene and a vinyl ester monomer and then saponifying the copolymer. 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 EVOH is preferably 20 mol% or more, more preferably 25 mol% or more, and preferably 60 mol% or less, more preferably 50 mol% or less. be. When the ethylene content is at least the lower limit, for example, the processing suitability of the rigid base material can be improved. When the ethylene content is at most the upper limit, for example, the rigidity and fragrance retention of the packaging bag can be improved, and the oxygen barrier properties and water vapor barrier properties of the rigid base material can be improved. The ethylene content rate is measured by NMR method.

The average degree of saponification in EVOH may be 90 mol% or more, 95 mol% or more, or 99 mol% or more. 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).

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

The melt flow rate (MFR) of EVOH is preferably 0.1 g/10 minutes or more, more preferably 0.3 g/10 minutes or more, and even more preferably 0.5 g/10 minutes from the viewpoint of film formability and processing suitability. or more, preferably 30 g/10 minutes or less, more preferably 20 g/10 minutes or less, even more preferably 10 g/10 minutes or less, particularly preferably 5.0 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. 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 average degree of saponification in polyvinyl alcohol (PVA) may be 70 mol% or more, 75 mol% or more, 80 mol% or more, or 85 mol% or more. The average degree of saponification is measured in accordance with JIS K6726.

Examples of polyamides include aliphatic polyamides and semi-aromatic polyamides. As the polyamide, aliphatic polyamide is preferable, and crystalline aliphatic polyamide is more preferable.

Examples of aliphatic polyamides include aliphatic homopolyamides and aliphatic copolyamides. In the following examples, polyamide is also referred to as "PA".

Specifically, the aliphatic homopolyamides include polycaprolactam (PA6), polyenanthlactam (PA7), polyundecanelactam (PA11), polylauryllactam (PA12), polyhexamethylene adipamide (PA66), and polyamide. Tetramethylene dodecamide (PA412), polypentamethylene azelamide (PA59), polypentamethylene sebacamide (PA510), polypentamethylene dodecamide (PA512), polyhexamethylene azeramide (PA69), polyhexamethylene sebaca Mido (PA610), polyhexamethylene dodecamide (PA612), polynonamethylene adipamide (PA96), polynonamethylene azeramide (PA99), polynonamethylene sebacamide (PA910), polynonamethylene dodecamide (PA912) ), polydecamethylene adipamide (PA106), polydecamethylene azeramide (PA109), polydecamethylene decamide (PA1010), polydecamethylene dodecamide (PA1012), polydodecamethylene adipamide (PA126), poly Mention may be made of dodecamethylene azeramide (PA129), polydodecamethylene sebacamide (PA1210) and polydodecamethylene dodecamide (PA1212).

Specifically, the aliphatic copolymer polyamides include caprolactam/hexamethylene diamino adipic acid copolymer (PA6/66), caprolactam/hexamethylene diamino azelaic acid copolymer (PA6/69), and caprolactam/hexamethylene diamino acid copolymer (PA6/69). Sebacic acid copolymer (PA6/610), caprolactam/hexamethylenediaminoundecanoic acid copolymer (PA6/611), caprolactam/hexamethylenediaminododecanoic acid copolymer (PA6/612), caprolactam/aminoundecanoic acid copolymer combination (PA6/11), caprolactam/lauryllactam copolymer (PA6/12), caprolactam/hexamethylene diamino adipic acid/lauryllactam copolymer (PA6/66/12), caprolactam/hexamethylene diamino adipic acid/hexa Examples include methylene diamino sebacic acid copolymer (PA6/66/610) and caprolactam/hexamethylene diamino adipic acid/hexamethylene diamino dodecane dicarboxylic acid copolymer (PA6/66/612).

The relative viscosity of the aliphatic polyamide is preferably 1.5 or more and 5.0 or less, more preferably 2.0 or more and 5.0 or less, and even more preferably 2.5 or more and 4.5 or less. The relative viscosity of the aliphatic polyamide is measured in accordance with JIS K6920 by dissolving 1 g of polyamide in 100 mL of 96% concentrated sulfuric acid at 25°C.

Semi-aromatic polyamide is a polyamide having a structural unit derived from an aromatic diamine and a structural unit derived from an aliphatic dicarboxylic acid, or a polyamide having a structural unit derived from an aliphatic diamine and a structural unit derived from an aromatic dicarboxylic acid. It is a polyamide having structural units. Examples include polyamides composed of aromatic diamines and aliphatic dicarboxylic acids, and polyamides composed of aliphatic diamines and aromatic dicarboxylic acids.

Examples of semi-aromatic polyamides include polyhexamethylene terephthalamide (PA6T), polyhexamethylene isophthalamide (PA6I), polynonamethylene terephthalamide (PA9T), and polyhexamethylene adipamide/polyhexamethylene terephthalamide copolymer. (PA66/6T), polyhexamethylene adipamide/polyhexamethylene isophthalamide copolymer (PA66/6I), polyhexamethylene terephthalamide/polycaproamide copolymer (PA6T/6), polyhexamethylene isophthalamide amide/polycaproamide copolymer (PA6I/6), polyhexamethylene terephthalamide/polydodecamide copolymer (PA6T/12), polyhexamethylene isophthalamide/polyhexamethylene terephthalamide copolymer (PA6I/6T), Polyhexamethylene terephthalamide/poly(2-methylpentamethylene terephthalamide) copolymer (PA6T/M5T), polyhexamethylene adipamide/polyhexamethylene terephthalamide/polyhexamethylene isophthalamide copolymer (PA66/6T) /6I), polyhexamethylene adipamide/polycaproamide/polyhexamethylene isophthalamide copolymer (PA66/6/6I), and polymethaxylylene adipamide (PAMXD6).

The melt volume rate (MVR) of the semi-aromatic polyamide is preferably from 5 cm ³ /10 minutes to 200 cm ³ /10 minutes, more preferably from 10 cm ³ /10 minutes to 100 cm ³ /10 minutes. MVR is measured at a temperature of 275° C. and a load of 5 kg in accordance with ISO1133.

As the polyamide, crystalline aliphatic polyamide is preferred. Examples of crystalline aliphatic polyamides include PA6, PA11, PA12, PA66, PA610, PA612, PA6/66 and PA6/66/12.

The melting point (Tm) of the crystalline aliphatic polyamide is preferably 180°C or higher, preferably 300°C or lower, more preferably 250°C or lower, even more preferably 230°C or lower. The Tm of polyamide is the melting peak temperature obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

The content ratio of the heteroatom-containing resin in the heteroatom-containing resin layer is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, particularly preferably 90% by mass or more, or 95% by mass or more. It is. Thereby, for example, the above-mentioned physical properties such as the rigidity of the packaging bag can be improved.

The heteroatom-containing resin layer may contain the above additives.

The thickness of the heteroatom-containing resin layer in the rigid base material is preferably 0.5 μm or more, more preferably 1.0 μm or more, even more preferably 1.5 μm or more, and preferably 10 μm or less, more preferably 8.0 μm. The thickness is preferably 6.0 μm or less. When the thickness is at least the lower limit, the above-mentioned physical properties such as the rigidity of the packaging bag can be improved, for example. When the thickness is below the upper limit, for example, the recyclability of the laminate can be improved. When the rigid base material includes two or more heteroatom-containing resin layers, the above-mentioned "thickness" means the total thickness of each heteroatom-containing resin layer.

The thickness of the heteroatom-containing resin layer is preferably 1% or more, more preferably 3% or more, even more preferably 5% or more, and preferably 30% or less, more preferably 3% or more, based on the thickness of the rigid base material. is 25% or less, more preferably 20% or less. When the rigid base material includes two or more heteroatom-containing resin layers, the above-mentioned "thickness" means the total thickness of each heteroatom-containing resin layer.

<Adhesive resin layer>
The rigid base material of the present disclosure may include an adhesive resin layer between the polyolefin layer and the heteroatom-containing resin layer. Thereby, for example, the adhesion between the polyolefin layer and the heteroatom-containing resin layer can be improved.

The adhesive resin layer contains a resin material. Examples of the resin material include polyolefin, modified polyolefin, vinyl resin, polyether, polyester, polyurethane, silicone resin, epoxy resin, and phenol resin. 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 polyolefin modifications, 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 resin materials, modified polyolefins are preferred from the viewpoint of obtaining a structure suitable for monomaterial packaging materials.

The melt flow rate (MFR) of the modified polyolefin may be 0.1 g/10 minutes or more, 0.3 g/10 minutes or more, or 0.5 g/10 minutes or more from the viewpoint of film formability and processing suitability. , 50 g/10 minutes or less, 30 g/10 minutes or less, or 10 g/10 minutes or less. The MFR of the modified polyolefin 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 changed depending on the melting point of the modified polyolefin.

The adhesive resin layer may contain the above additive.

The thickness of the adhesive resin layer is preferably 0.5 μm or more, more preferably 1.0 μm or more, and preferably 15 μm or less, more preferably 10 μm or less. For example, when the thickness is at least the lower limit, the adhesion can be improved. When the thickness is below the upper limit, for example, the recyclability of the laminate can be improved. When the rigid base material includes two or more adhesive resin layers, the above "thickness" means the total thickness of each adhesive resin layer.

Specifically, the rigid base material includes (1) a stretched base material comprising a medium-density polyethylene layer, an adhesive resin layer, and a heteroatom-containing resin layer in this order; (2) a medium-density polyethylene layer and a medium-density polyethylene layer; Stretched base material comprising a density polyethylene layer, a medium density polyethylene layer, an adhesive resin layer, and a heteroatom-containing resin layer in this order; (3) a medium-density polyethylene layer, an adhesive resin layer, and a heteroatom-containing resin An example is a stretched base material comprising a layer, an adhesive resin layer, and a medium density polyethylene layer in this order. Here, the medium density polyethylene layer contains medium density polyethylene as a main component. When producing a laminate described below using the stretched base material (1) or (2), for example, the heteroatom-containing resin layer is arranged so as to face the sealant layer side.

[Printing base material]
The printed base material of the present disclosure includes the above-described rigid base material of the present disclosure and a printing layer provided on one surface or both surfaces of the rigid base material.
The printing layer contains an image. Examples of images include characters, figures, patterns, symbols, and combinations thereof. The image may include text information such as the product name, the name of the contents in the packaging bag, the manufacturer, and the name of raw materials. The image may be a solid color (a so-called solid image).

The printing layer contains, for example, coloring materials such as pigments and dyes. The printing layer may be formed using biomass-derived ink, for example. Thereby, for example, the environmental load can be further reduced. The printed layer may be, for example, a white layer.

Examples of methods for forming the printed layer include conventionally known printing methods such as gravure printing, offset printing, and flexographic printing. From the viewpoint of reducing environmental impact, a flexographic printing method may be used.

The thickness of the printed layer may be 0.5 μm or more, 1.0 μm or more, 10 μm or less, 6.0 μm or less, or 4.0 μm or less.

The printed layer may be formed on either side of the rigid base material.

[Laminated body]
The laminate of the present disclosure includes at least a stretched base material and a sealant layer.
The laminate of the present disclosure can be suitably used as a packaging material.

The stretched substrate is a rigid substrate of the present disclosure. When the laminate of the present disclosure includes two or more stretched base materials, at least one stretched base material may be the rigid base material of the present disclosure, and the laminate of the present disclosure may include a stretched base material other than the rigid base material of the present disclosure. There is no hindrance to further providing a base material.
The sealant layer contains polyolefin as a main component.

In one embodiment, when the main components of the resin constituting the stretched base material and the resin constituting the sealant layer are both polyolefins, the recyclability of the laminate can be improved, for example.

The content of polyolefin (specifically polyethylene or polypropylene) in the entire laminate of the present disclosure is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, particularly preferably 95% by mass. % or more. Thereby, for example, a monomaterial packaging bag can be produced using the above-mentioned laminate, and the recyclability of the packaging bag can be improved. The upper limit of the polyolefin content is not particularly limited, but may be 99% by mass.

The oxygen permeability of the laminate of the present disclosure is preferably 200 cc/m ² ·day · atm or less, more preferably 50 cc/m ² ·day · atm or less, even more preferably 10 cc/m ² ·day · atm or less, especially Preferably it is 4 cc/m ² ·day · atm or less. The lower limit of the oxygen permeability may be, for example, 0.1 cc/m ² ·day · atm or 1 cc/m ² ·day · atm. Oxygen permeability is measured in accordance with JIS K7126-2 (isobaric method) at a temperature of 23° C. and a humidity of 90% RH.

The water vapor permeability of the laminate of the present disclosure is preferably 10 g/m ² ·day or less, more preferably 5 g/m ² ·day or less, even more preferably 3 g/m ² ·day or less, particularly preferably 2 g/m ²・It is less than 1 day. The lower limit of water vapor permeability may be, for example, 0.1 g/m ² ·day. Water vapor permeability is measured in accordance with JIS K7129 (Method B) at a temperature of 40° C. and a humidity of 90% RH.

The laminate of the present disclosure has excellent rigidity.
In one embodiment, the loop stiffness value of the laminate of the present disclosure in the MD direction is preferably 150 mN or more, more preferably 165 mN or more, and still more preferably 180 mN or more. The upper limit of the loop stiffness value in the MD direction is not particularly limited, but is, for example, 400 mN. The loop stiffness value in the MD direction is measured for a test piece whose length direction is along the MD direction of the laminate.

In one embodiment, the loop stiffness value of the laminate of the present disclosure in the TD direction is preferably 180 mN or more, more preferably 190 mN or more, and still more preferably 200 mN or more. The upper limit of the loop stiffness value in the TD direction is not particularly limited, but is, for example, 400 mN. The loop stiffness value in the TD direction is measured for a test piece whose length direction is along the TD direction of the laminate.

The loop stiffness value is measured as follows. The laminate is cut into a size of 15 mm in width and 100 mm in length to obtain a test piece. Both ends of the test piece are held between clips so that the sealant layer of the test piece is on the inside, and a circular loop with a loop length of 60 mm is formed at the center of the test piece. The loop stiffness value is measured by pushing the obtained circular loop (width 15 mm x loop length 60 mm) from the opposite side of the clip at a pushing speed of 3.3 mm/sec.

The laminate of the present disclosure has excellent heat resistance as described above. Therefore, the laminate of the present disclosure can be heat-sealed at a higher temperature than conventional monomaterial laminates. For example, in the laminate of the present disclosure, the heat seal strength of the sealed portion heat-sealed under the following conditions is preferably 20 N/15 mm or more, more preferably 30 N/15 mm or more, and still more preferably 40 N/15 mm or more. The upper limit of the heat sealing strength is not particularly limited, but is, for example, 100N/15mm. The heat seal strength is measured by a tensile test (tensile speed: 300 mm/min) according to JIS Z1707. Details of the measurement conditions are described in the Examples column.
(conditions)
・Seal temperature 170℃ (single side heating)
・Seal pressure 1kgf/cm ²
・Sealing time: 1 second ・Prepare two laminates, place them one on top of the other with the sealant layer sides facing each other, and heat seal one end using a heat sealing machine.

<Print layer>
The laminate of the present disclosure may include a printed layer. The printing layer contains an image. Examples of images include characters, figures, patterns, symbols, and combinations thereof. The image may include text information such as the product name, the name of the contents in the packaging bag, the manufacturer, and the name of raw materials. The image may be a solid color (a so-called solid image).

The printing layer contains, for example, coloring materials such as pigments and dyes. The printing layer may be formed using biomass-derived ink, for example. Thereby, for example, the environmental load can be further reduced. The printed layer may be, for example, a white layer.

Examples of methods for forming the printed layer include conventionally known printing methods such as gravure printing, offset printing, and flexographic printing. From the viewpoint of reducing environmental impact, a flexographic printing method may be used.

The thickness of the printed layer may be 0.5 μm or more, 1.0 μm or more, 10 μm or less, 6.0 μm or less, or 4.0 μm or less.

The printed layer may be formed on either side of the stretched base material. The printed layer is preferably formed on the surface of the stretched base material on the sealant layer side, since contact between the printed layer and the outside air can be suppressed and deterioration of the printed layer over time can be suppressed.

<Sealant layer>
The laminate of the present disclosure includes a sealant layer.
The sealant layer contains polyolefin as a main component. This allows the packaging bag to be made of monomaterial. After collecting used packaging bags, there is no need to separate the stretched base material and the sealant layer, and the recyclability of the packaging bags can be improved.

Among polyolefins, polyethylene and polypropylene are preferred.

In one embodiment, the sealant layer contains polyethylene as a main component. Examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene. and very low density polyethylene are preferred. As the polyethylene, from the viewpoint of reducing environmental load, biomass-derived polyethylene, mechanically recycled or chemically recycled polyethylene may be used.

From the viewpoint of heat sealability, the sealant layer preferably contains low density polyethylene and linear low density polyethylene. From the viewpoint of tearability, the sealant layer preferably contains low density polyethylene. When the sealant layer contains low-density polyethylene and linear low-density polyethylene, the content ratio (mass %) of the linear low-density polyethylene may be larger than the content ratio (mass %) of the low-density polyethylene.

The melting point (Tm) of the polyethylene constituting the sealant layer is preferably 90°C or higher, more preferably 95°C or higher, and preferably 140°C or lower, more preferably 130°C or higher, from the viewpoint of the balance between heat resistance and heat sealability. below ℃.

The content of polyethylene in the sealant layer is preferably 50% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass or more. Thereby, for example, the recyclability of the packaging bag can be improved.

In one embodiment, the sealant layer contains polypropylene as a main component. Thereby, for example, the oil resistance of the packaging bag can be improved.

Examples of polypropylene include propylene homopolymers, propylene random copolymers such as propylene-α-olefin random copolymers, and propylene block copolymers such as propylene-α-olefin block copolymers. Details of the α-olefin are as described above. As the polypropylene, from the viewpoint of reducing environmental load, biomass-derived polypropylene, mechanically recycled or chemically recycled polypropylene may be used.

From the viewpoint of heat sealability, the density of polypropylene is, for example, 0.88 g/cm ³ or more and 0.92 g/cm ³ or less.

The melting point (Tm) of the polypropylene constituting the sealant layer is preferably 120°C or higher, more preferably 125°C or higher, even more preferably 130°C or higher, and preferably 160°C or higher, from the viewpoint of the balance between heat resistance and heat sealability. The temperature is preferably 155°C or lower, more preferably 150°C or lower.

The content of polypropylene in the sealant layer is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 70% by mass or more. Thereby, for example, the recyclability of the packaging bag can be improved.

The MFR of the polyolefin constituting the sealant layer is preferably 0.1 g/10 minutes or more, more preferably 0.3 g/10 minutes or more, and even more preferably 0.5 g/10 minutes, from the viewpoint of film formability and processing suitability. or more, preferably 50 g/10 minutes or less, more preferably 30 g/10 minutes or less, still more preferably 10 g/10 minutes or less. For example, when the MFR is at least the lower limit, the processability of the sealant layer can be improved. For example, film formability can be improved if the MFR is below the upper limit.

The content of polyolefin in the sealant layer is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 75% by mass or more. Thereby, for example, the recyclability of the packaging bag can be improved.

The sealant layer may contain the above additives.

The thickness of the sealant layer is preferably 10 μm or more, more preferably 30 μm or more, even more preferably 50 μm or more, particularly preferably 80 μm or more, and preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less. . When the sealant layer has a multilayer structure, the total thickness thereof is preferably within the above range. When the thickness is at least the lower limit, for example, the heat sealability of the sealant layer and the recyclability of the packaging bag can be improved. When the thickness is below the upper limit, for example, the processability of the laminate can be improved.

From the viewpoint of heat sealability, the sealant layer is preferably an unstretched resin film, more preferably an unstretched coextruded resin film, and each layer constituting the sealant layer is a coextruded resin layer. The resin film can be produced by, for example, a casting method, a T-die method, an inflation method, or the like. "Unstretched" is a concept that includes not only a film that has not been stretched at all, but also a film that has been slightly stretched due to the tension applied during film formation.

For example, an unstretched resin film corresponding to the sealant layer may be laminated on a stretched base material via an adhesive layer as necessary, or by melt-extruding a polyolefin or its resin composition onto a stretched base material. A sealant layer may also be formed. In the latter case, the adhesive layer may not be provided. Examples of the adhesive layer include the adhesive layer described below.

<Embodiment of sealant layer>
The sealant layer containing polyethylene as a main component may include a first layer and a second layer described below. The first layer contains an ethylene/α-olefin copolymer as a main component and has a melting point of 112° C. or lower. The second layer contains polyethylene as a main component and has a melting point of 114° C. or higher. The first layer can improve low-temperature sealing properties, and the second layer can improve rigidity and hand-cutting properties.

The stretched base material, which mainly contains polyethylene, is composed of polyethylene that has a lower melting point than conventional resin films such as polyester and nylon, so the heat sealing temperature when manufacturing packaging bags using the laminate is lower. cannot be made too high. In the case of a sealant layer comprising a first layer and a second layer, the first layer can be heat-sealed at a lower temperature than the second layer. Also, the sealing properties of the packaging bag can be maintained.

Stretched base material made of polyethylene has higher tear strength than resin films such as polyester or nylon, so when the laminate is processed into a packaging bag, the tearability (tearability) when opening the bag may be reduced. . By combining the stretched base material and the sealant layer of the above embodiment, the tearability of the laminate is improved. Although the reason for this is not clear, it can be assumed that the sealant layer, which includes the second layer having a melting point of 114° C. or higher, improves the toughness and further improves the tearability of the laminate.

In this specification, the melting point of a layer is a value determined in accordance with JIS K7121:2012 using a differential scanning calorimeter. Specifically, a sample is taken from each layer of the sealant layer, and the melting point is measured by the method described in the Examples section.

(first layer)
The first layer in the sealant layer contains an ethylene/α-olefin copolymer as a main component and has a melting point of 112° C. or lower. Thereby, as described above, the low-temperature sealing properties of the sealant layer can be improved. The first layer is one surface layer of the sealant layer and also one surface layer of the laminate. The first layer is the layer facing the contents contained in the packaging bag.

Examples of the ethylene/α-olefin copolymer include linear polyethylene. Linear polyethylene is a copolymer of ethylene and α-olefin, which is obtained using, for example, a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst. The linear polyethylene having a density of 0.930 g/cm ³ or less is, for example, linear low density polyethylene.

The α-olefin that is a comonomer of the above copolymer is, for example, an α-olefin having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1- Examples include nonene and 4-methylpentene, and tearability tends to improve as the number of carbon atoms increases. In consideration of low-temperature sealability and tearability, 1-hexene and 1-octene are preferred as the α-olefin.

Polyethylene can be produced using, for example, a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst as a polymerization catalyst. A single-site catalyst is a catalyst capable of forming uniform active species, and is usually prepared by bringing a metallocene transition metal compound or a non-metallocene transition metal compound into contact with an activation cocatalyst. Single-site catalysts are preferable compared to multi-site catalysts because they have a uniform structure of active sites and can yield polymers with high molecular weight and highly uniform structures. As the single site catalyst, a metallocene catalyst is preferred. In addition, by using an ethylene/α-olefin copolymer produced using a metallocene catalyst in the first layer, an ethylene/α-olefin copolymer produced using a Ziegler-Natta catalyst can be used. For example, low-temperature sealing performance can be further improved than in the case of the conventional method. By using an ethylene/α-olefin copolymer produced using a metallocene catalyst in the second layer or third layer described below, the ethylene/α-olefin copolymer produced using a Ziegler-Natta catalyst can be used. For example, impact resistance can be improved more than when a polymer is used.

From the viewpoint of low-temperature sealing properties of the sealant layer, the melting point of the first layer is preferably 110°C or lower, more preferably 105°C or lower, even more preferably 100°C or lower, and may be 80°C or higher, or even 90°C or higher. good.

The difference between the melting point of the second layer and the first layer is preferably 4°C or higher, more preferably 15°C or higher, and even more preferably 20°C, from the viewpoint of the low-temperature sealing property and rigidity balance of the sealant layer. The temperature is preferably 50°C or lower, more preferably 48°C or lower, even more preferably 46°C or lower, and may be, for example, 40°C or lower.

The density of the first layer is preferably 0.915 g/cm ³ or less, more preferably 0.912 g/cm ³ or less, even more preferably 0.908 g/cm ³ or less, and even 0.890 g/cm ³ or more. It may be 0.900 g/cm ³ or more. By setting the density of the first layer to 0.915 g/cm ³ or less, for example, the low-temperature sealing properties of the sealant layer can be improved. By setting the density of the first layer to 0.890 g/cm ³ or more, for example, the blocking resistance of the laminate can be improved.

The content of the ethylene/α-olefin copolymer in the first layer is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more.

In one embodiment ^{, the} first layer ^is an ethylene/α- Contains olefin copolymer. The density of the ethylene/α-olefin copolymer is preferably 0.890 g/cm ³ or more, more preferably 0.895 g/cm ³ or more. When the first layer contains an ethylene/α-olefin copolymer having a density of 0.912 g/cm ³ or less, the low-temperature sealing properties of the sealant layer can be improved, for example. When the density of the ethylene/α-olefin copolymer is 0.890 g/cm ³ or more, the blocking resistance of the laminate can be improved, for example.

The thickness of the first layer may be 5 μm or more, 15 μm or more, 50 μm or less, or 30 μm or less. The first layer may be a single layer or a multilayer with each layer having the same composition. If the first layer is multilayer, the thickness of the first layer is the total thickness of each layer.

The ratio of the thickness of the first layer to the thickness of the sealant layer is preferably 3% or more, more preferably 5% or more, even more preferably 10% or more, particularly preferably 15% or more, and preferably 40%. Below, it is more preferably 35% or less, still more preferably 30% or less, particularly preferably 25% or less. Thereby, for example, the balance between low-temperature sealing performance and rigidity of the sealant layer can be further improved.

In one embodiment, the first layer is preferably in contact with the second layer or the third layer, and more preferably in contact with the second layer. That is, in one embodiment, the first layer is preferably in contact with the second layer or the third layer without an adhesive layer interposed therebetween.
In one embodiment, the first layer is an unstretched resin layer.

The first layer may contain the above additives.

(Second layer)
The second layer in the sealant layer contains polyethylene as a main component and has a melting point of 114° C. or higher. Thereby, as described above, the rigidity of the sealant layer can be improved.

From the viewpoint of the rigidity of the sealant layer, the melting point of the second layer is preferably 117°C or higher, more preferably 120°C or higher, and may be 150°C or lower, or 135°C or lower.

The density of the second layer is preferably 0.916 g/cm ³ or more, more preferably 0.917 g/cm ³ or more, even more preferably 0.920 g/cm ³ or more, particularly preferably 0.930 g/cm ³ or more. It may be 0.950 g/cm ³ or less, or may be 0.945 g/cm ³ or less. By setting the density of the second layer to 0.916 g/cm ³ or more, for example, the rigidity and tearability of the sealant layer can be improved. By setting the density of the second layer to 0.950 g/cm ³ or less, for example, the impact resistance of the sealant layer can be improved.

The content of polyethylene in the second layer is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, particularly preferably 95% by mass or more.

The second layer, in one embodiment, preferably contains polyethylene having a density of 0.915 g/cm ³ or more, more preferably 0.935 g/cm ^{3 or} more. The density of the polyethylene is preferably 0.970 g/cm ³ or less, more preferably 0.960 g/cm ³ or less. When the second layer contains polyethylene having a density of 0.915 g/cm ³ or more, for example, the rigidity and tearability of the sealant layer can be improved. When the density of the polyethylene is 0.970 g/cm ³ or less, for example, the impact resistance of the sealant layer can be improved.

The second layer may contain an ethylene/α-olefin copolymer as the polyethylene. The content of the ethylene/α-olefin copolymer in the second layer is preferably 50% by mass or more, more preferably 70% by mass or more, and preferably 90% by mass, based on the entire second layer. The content is preferably 80% by mass or less. By controlling the content of the ethylene/α-olefin copolymer to 50% by mass or more, for example, the impact resistance of the sealant layer can be improved. By controlling the content of the ethylene/α-olefin copolymer to 90% by mass or less, for example, the tearability of the sealant layer can be improved.

The second layer may contain an ethylene homopolymer as the polyethylene. The content ratio of the ethylene homopolymer in the second layer is preferably 10% by mass or more, more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 15% by mass or more, based on the entire second layer. Preferably it is 25% by mass or less. By setting the content of the ethylene homopolymer to 10% by mass or more, for example, the tearability of the sealant layer can be improved. By controlling the content of the ethylene homopolymer to 50% by mass or less, for example, the impact resistance of the sealant layer can be improved.

In one embodiment, when the sealant layer is composed of two layers, the second layer is the surface layer of the sealant layer on the stretched substrate side. In one embodiment, when the sealant layer is composed of three or more layers, the second layer is a surface layer and/or an intermediate layer on the stretched substrate side in the sealant layer. In this case, the first layer and the intermediate layer are preferably made of different constituent materials from the viewpoint of the balance between low-temperature sealability and rigidity.

Intermediate layer means a layer located between one surface layer and the other surface layer of the sealant layer. The intermediate layer may be a single layer or a multilayer. When the intermediate layer is multilayered, the composition of each intermediate layer may be the same or different.

The second layer may be a plurality of layers in the sealant layer as long as it contains polyethylene as a main component and has a melting point of 114° C. or higher. For example, both the surface layer and the intermediate layer on the stretched base material side may be the second layer.

The thickness of the second layer may be 10 μm or more, 45 μm or more, 250 μm or less, or 170 μm or less. If the second layer is multilayer, the thickness of the second layer is the total thickness of each layer.

In one embodiment, the second layer is an unstretched resin layer.

The second layer may contain the additives described above.

(Third layer)
The sealant layer may further include a third layer in addition to the first layer and the second layer. The third layer is a layer containing polyethylene as a main component, and is a layer that does not correspond to the first layer or the second layer.

In one embodiment, the third layer is a surface layer and/or an intermediate layer on the side of the stretched substrate.
The third layer may be a plurality of layers within the sealant layer.

In one embodiment, the third layer is an unstretched resin layer.

The third layer may contain the above additives.

(Structure of sealant layer)
For example, the layer structure of the sealant layer containing polyethylene as a main component is as follows:
・First layer/second layer,
・First layer/second layer/first layer,
・First layer/second layer/second layer,
・First layer/second layer/third layer,
・First layer/third layer/second layer,
can be mentioned. "/" means between layers.

For example, when the sealant layer includes a first layer, an intermediate layer, and a surface layer on the stretched base material side, it is preferable that the melting point of the intermediate layer is higher than that of the surface layer on the stretched base material side. Further, it is preferable that the melting point of the intermediate layer is higher than that of the first layer. Further, it is preferable that the melting point of the surface layer on the stretched base material side is higher than the melting point of the first layer. With such a configuration, for example, the low-temperature sealability, rigidity, and impact resistance of the sealant layer can be further improved.

For example, the difference between the melting point of the intermediate layer and the melting point of the surface layer on the stretched base material side may be 0°C or more and 30°C or less, 1°C or more, 2°C or more, or 25°C or less, or 20°C or more. The temperature may be below 15°C, or below 10°C. For example, the difference between the melting point of the intermediate layer and the first layer may be 2°C or more and 50°C or less, 4°C or more, 15°C or more, or 40°C or less, or 35°C or less. good. For example, the difference between the melting point of the surface layer on the stretched base material side and the melting point of the first layer may be 2°C or more and 40°C or less, 4°C or more, 15°C or more, or 35°C or less. , 30°C or lower.

In a sealant layer comprising a first layer, an intermediate layer, and a surface layer on the stretched base material side, the ratio of the thickness of the first layer to the thickness of the sealant layer and the thickness of the surface layer on the stretched base material side are The proportions are each independently preferably 3% or more, more preferably 5% or more, even more preferably 10% or more, particularly preferably 15% or more, preferably 40% or less, more preferably 35% or less, and Preferably it is 30% or less, particularly preferably 25% or less.

In a sealant layer comprising a first layer, an intermediate layer, and a surface layer on the stretched base material side, the ratio of the thickness of the intermediate layer to the thickness of the sealant layer is preferably 20% or more, more preferably 30% or more. , more preferably 40% or more, particularly preferably 50% or more, preferably 94% or less, more preferably 90% or less, still more preferably 80% or less, particularly preferably 70% or less.

In one embodiment, the sealant layer does not have an adhesive layer between each layer selected from the first layer, the second layer, and optionally the third layer constituting the sealant layer. For example, the sealant layer is a coextruded resin film.

The content of the ethylene/α-olefin copolymer in the sealant layer is preferably 50% by mass or more, more preferably 70% by mass or more, and preferably 90% by mass or less, more preferably is 80% by mass or less. By controlling the content of the ethylene/α-olefin copolymer to 50% by mass or more, for example, the impact resistance of the sealant layer can be improved. By controlling the content of the ethylene/α-olefin copolymer to 90% by mass or less, for example, the tearability of the sealant layer can be improved.

The content of the ethylene homopolymer in the sealant layer is preferably 10% by mass or more, more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 25% by mass, based on the entire sealant layer. % or less. By setting the content of the ethylene homopolymer to 10% by mass or more, for example, the tearability of the sealant layer can be improved. By controlling the content of the ethylene homopolymer to 50% by mass or less, for example, the impact resistance of the sealant layer can be improved.

The surface of the sealant layer opposite the first layer may be subjected to a surface treatment. Thereby, adhesion between adjacent layers can be improved. Specific examples of the surface treatment are as described above.

<Adhesive layer>
The laminate of the present disclosure may include an adhesive layer between arbitrary layers such as between the stretched base material and the sealant layer. Thereby, the adhesiveness between the stretched base material and the sealant layer can be improved.

The thickness of the adhesive layer may be 0.1 μm or more, 0.2 μm or more, 0.5 μm or more, 10 μm or less, 8.0 μm or less, or 6.0 μm or less. The thickness of the adhesive layer may be 2.0 μm or less.

In one embodiment, the adhesive layer may be an adhesive layer made of adhesive. The adhesive may be a one-component curing adhesive, a two-component curing adhesive, or a non-curing adhesive. The adhesive may be a solvent-free adhesive or a solvent-based adhesive.

Examples of solvent-free adhesives, that is, 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.

Examples of solvent-based adhesives include rubber adhesives, vinyl adhesives, olefin adhesives, silicone adhesives, epoxy adhesives, phenolic adhesives, and urethane adhesives.

In one embodiment, by forming the adhesive layer using a solvent-free adhesive, the amount of residual solvent, specifically, the amount of residual organic solvent in the laminate can be further reduced, for example. Examples of organic solvents 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, isopropyl alcohol, Alcohol solvents such as n-butyl alcohol and isobutyl alcohol; and ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone.

In one embodiment, using a solvent-free adhesive allows, for example, a thinner adhesive layer than when using a solvent-based adhesive. Thereby, the content ratio of polyolefin in the entire laminate can be further improved. Such a laminate is suitable for producing a monomaterial packaging bag. In one embodiment, by using a solvent-free adhesive, the tearability of the laminate can be improved more than when using a solvent-based adhesive.

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 polyhydric carboxylic 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 biurets, nurates, 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 Amines include diethanolamine, triethanolamine and metaxylylene diamine. Examples of the polymeric active hydrogen compound include polyester, polyether polyol, and polyamide.

The adhesive layer may be an adhesive resin layer containing a thermoplastic resin. Examples of thermoplastic resins include high-density polyethylene, medium-density polyethylene, high-pressure low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, and ethylene-vinyl acetate copolymer. Methyl (meth)acrylate copolymer, ethylene-ethyl (meth)acrylate copolymer, ethylene-maleic acid copolymer, ionomer resin, and polyolefin with unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, or monoester. Examples include resins obtained by graft polymerization or copolymerization of polymers. The thermoplastic resin may be a fossil fuel-derived material, a biomass-derived material, or both.

In one embodiment, the laminate of the present disclosure may be manufactured by bonding a stretched base material and a resin film corresponding to the sealant layer by a non-solvent laminating method using a solvent-free adhesive. They may be manufactured by bonding them together by a dry lamination method using a solvent-based adhesive.

<Layer configuration of laminate>
Hereinafter, several examples will be given regarding the layer structure of the laminate of the present disclosure.
The laminate 5 shown in FIG. 4 includes a rigid base material 1, an adhesive layer 6, and a sealant layer 8 in this order. The laminate 5 may further include a printed layer (not shown) on the surface of the rigid base material 1 on the sealant layer 8 side.

[Packaging bag]
The laminate of the present disclosure can be suitably used for packaging material applications. Packaging materials are used to make packaging bags. By using at least the laminate of the present disclosure, a packaging bag with excellent rigidity can be manufactured. The packaging bag may be a refill pouch, particularly a standing pouch, that accommodates fluid contents such as liquid or powder that is refilled into a container such as a bottle.

Examples of packaging bags include standing pouch type, side seal type, two side seal type, three side seal type, four side seal type, envelope sticker type, gasho sticker type (pillow seal type), pleated seal type, and flat bottom seal type. There are various types of packaging bags, such as a type, a square bottom seal type, and a gusset type. The packaging bag may be, for example, a small bag or a zipper bag.
The packaging bag may be, for example, a flexible packaging bag.

The packaging bag of the present disclosure includes the laminate of the present disclosure.
The packaging bag of the present disclosure includes, for example,
a storage section that accommodates the contents;
a sealing part where the sealant layers of the laminate are joined;
has.
The seal portion includes an inner edge that defines a housing portion.
The packaging bag may further include an easy-to-open line to increase the tearability of the packaging bag.
The packaging bag may further include a notch that serves as a starting point for tearing.

<Seal part>
The packaging bag has a seal portion where the sealant layers of the laminate are joined together.
Examples of methods for forming the seal portion include heat sealing, in which the sealant layers of the laminate are melted by heating and the sealant layers are fused together, and specifically, bar seals, rotating roll seals, belt seals, Impulse seals, high frequency seals and ultrasonic seals may be mentioned.

<Contents>
Examples of the contents accommodated in the packaging bag include liquids, solids, powders, and gels. The contents may be food or beverages, or non-food or beverages such as chemicals, cosmetics, and pharmaceuticals. After the contents are placed in the packaging bag, the packaging bag can be sealed by heat-sealing the opening of the packaging bag.

Contents include, for example, shampoo, conditioner, conditioner, hand soap, body soap, fragrance, deodorant, deodorant, insect repellent, fabric softener, detergent; sauce, soy sauce, dressing, edible oil, mayonnaise, ketchup, Examples include syrups, cooking alcoholic beverages, other liquid or viscous seasonings; fruit juices; spices; liquid drinks, jelly drinks, liquid soups, powdered soups, instant foods, other food and drink products; and creams. In one embodiment, the packaging bag of the present disclosure has excellent fragrance retention as described above, even though it is a monomaterial packaging material. Therefore, even when the packaging bag is filled with strong-smelling contents such as shampoo, conditioner, conditioner, fabric softener, and detergent, leakage of odor can be suppressed.

<Preparation of packaging bag>
In one embodiment, a packaging bag is produced by folding the laminate of the present disclosure in half so that the stretched base material is on the outside and the sealant layer is on the inside, stacking them on top of each other, and heat-sealing the edges and the like. can. In another embodiment, a packaging bag can be produced by stacking a plurality of laminates of the present disclosure so that the sealant layers face each other and heat-sealing the ends and the like. The entire packaging bag may be composed of the above-mentioned laminate, or a part of the packaging bag may be composed of the above-mentioned laminate.

<Embodiment of packaging bag>
Hereinafter, several examples of embodiments of the packaging bag of the present disclosure will be described based on the drawings.
FIG. 5 is a front view showing the packaging bag 10 of one embodiment. FIG. 5 shows the packaging bag 10 in a state before it is filled with contents (in a state in which no contents are accommodated). The packaging bag 10 is a gusset-type pouch configured to be self-supporting. The packaging bag 10 includes an upper part 11, a lower part 12, and a side part 13, and has a substantially rectangular outline in a front view. Names such as "upper part,""lowerpart," and "side part," and terms such as "upper part" and "lower part" are based on the state in which the packaging bag 10 stands on its own with the gusset section facing down. It is merely a relative representation of the positions and directions of 10 and its constituent elements. The posture of the packaging bag 10 during transportation or use is not limited by the names and terms used in this specification.

The packaging bag 10 has a storage section 17 and a seal section 19. The accommodating portion 17 accommodates contents. The seal portion 19 includes an inner edge 19x that defines the housing portion 17. The seal portion 19 is constructed by joining together the sealant layers of the laminate that constitutes the packaging bag 10. In a plan view such as FIG. 5, the seal portion 19 is hatched.

The accommodating portion 17 may include a spout portion 20 . The spout portion 20 is a portion through which the contents are taken out from the packaging bag 10. The width of the spout portion 20 is narrower than the width of the other portions of the accommodating portion 17. Therefore, the user can accurately determine the direction in which the contents are poured out from the packaging bag 10 through the spout section 20.

The packaging bag 10 may have an easy-open line 26. The easy-to-open line 26 can be formed on the packaging bag 10, for example, in order to improve the tearability of the packaging bag 10. The easy-to-open line 26 crosses the accommodating portion 17 when the packaging bag 10 is viewed from above. In the example shown in FIG. 5, the easy-to-open line 26 crosses the spout portion 20 in plan view. As shown in FIG. 5, a cutout 28 adjacent to the easy-open line 26 may be formed at the outer edge of the packaging bag 10. Instead of the notch 28, a notch may be formed on the outer edge of the packaging bag 10.

The packaging bag 10 includes a front film 14 constituting the front surface, a back film 15 constituting the back surface, and a lower film 16 constituting the lower part 12. The lower film 16 is placed between the front film 14 and the back film 15 in a folded state at the folded portion 16f.

Either or both of the front film 14 and the back film 15 are constructed from the laminate of the present disclosure. The lower film 16 may also be comprised of the laminate of the present disclosure. The laminate includes an inner surface and an outer surface. The inner surface is the surface that comes into contact with the contents. The outer surface is the surface opposite the inner surface. The sealant layer is located on the inner surface side with respect to the stretched substrate.

The terms "front film", "back film", and "lower film" are merely divisions of each film according to their positional relationship, and the method of providing the film when manufacturing the packaging bag 10 is defined by the above-mentioned terms. is not limited by. For example, the packaging bag 10 may be manufactured using one film in which the front film 14, the back film 15, and the lower film 16 are arranged in series, or the packaging bag 10 in which the front film 14 and the lower film 16 are arranged in series. It may be manufactured using a total of two films, one film and one back film 15, or a total of three films, one front film 14, one back film 15, and one bottom film 16. It may also be manufactured using a film.

As shown in FIG. 5, the seal portion 19 includes a lower seal portion 12a, a side seal portion 13a, and a spout seal portion 20a. The lower seal portion 12a extends to the lower portion 12. The side seal portion 13a extends along the pair of side portions 13. The spout seal portion 20a defines the spout portion 20. The distance between the inner edges of the spout seal portions 20a is smaller than the distance between the inner edges of the pair of side seal portions 13a. When the spout part 20 is formed at a corner between the top 11 and the side part 13 of the packaging bag 10, the spout seal part 20a is connected to the side seal part 13a.

In the packaging bag 10 in a state where no contents are stored, as shown in FIG. 5, the upper part 11 of the packaging bag 10 has an opening 11b. After the contents are stored in the packaging bag 10 through the opening 11b, the sealant layer of the front film 14 and the sealant layer of the back film 15 are joined at the upper part 11, thereby forming an upper seal part in the opening 11b. Ru. Thereby, the accommodating portion 17 is sealed from the outside of the packaging bag 10.

The side seal portion 13a, the spout seal portion 20a, and the top seal portion are constructed by joining the sealant layer of the front film 14 and the sealant layer of the back film 15. The lower seal portion 12a includes a portion where the sealant layer of the front film 14 and a sealant layer of the lower film 16 are joined, and a portion where the sealant layer of the back film 15 and the sealant layer of the lower film 16 are joined. include. As shown by the dotted line labeled 13c in FIG. 5, a cutout may be formed in a portion of the lower film 16. At the position of the notch, the sealant layer of the front film 14 and the sealant layer of the back film 15 may be joined.

Next, the layer structure of the lower film 16 will be explained.
The layer structure of the lower film 16 is arbitrary as long as it has an inner surface that can be joined to the sealant layer of the front film 14 and the sealant layer of the back film 15. For example, similarly to the front film 14 and the back film 15, the above-mentioned laminate may be used as the lower film 16. A film having a structure different from that of the laminate of the present disclosure may be used as the lower film 16.

The packaging bag 10 can be produced, for example, as follows. A laminate of the present disclosure is prepared. Cut the laminate into two. Thereby, a front film 14 and a back film 15 are obtained. Subsequently, the folded lower film 16 is inserted between the front film 14 and the back film 15. Subsequently, the sealant layers of each film are heat-sealed to form seal parts such as the lower seal part 12a, the side seal part 13a, and the spout seal part 20a. The films joined together by heat sealing are cut into appropriate shapes. Thereby, the packaging bag 10 shown in FIG. 5 is obtained.

Subsequently, the accommodating portion 17 of the packaging bag 10 is filled with the contents. Thereafter, the upper portion 11 is heat-sealed to form an upper sealed portion. In this way, a sealed packaging bag 10 containing the contents is obtained.

In the above description of the embodiment, an example in which the packaging bag 10 is a gusset-type pouch has been shown, but the specific configuration of the packaging bag 10 is not particularly limited.

For example, the packaging bag 10 may not include the lower film 16, as shown in FIGS. 6 and 7. In FIGS. 6 and 7, the lower seal part 12a and the side seal part 13a of the packaging bag 10 are formed by bonding the sealant layers of the front film 14 and the back film 15, which are laminates, respectively. After the contents are stored in the packaging bag 10, the packaging bag 10 is sealed by joining the sealant layer of the front film 14 and the sealant layer of the back film 15 at the opening 11b of the upper part 11. The packaging bag 10 shown in FIGS. 6 and 7 may have an easy-to-open line 26.

As shown in FIG. 8, the packaging bag 10 may be a pillow pouch. The packaging bag 10 includes a folded palm portion 18 formed by overlapping the ends of the laminate that constitutes the front film 14 and the back film 15. The palms in prayer portion 18 includes a palms in prayer portion seal portion 18a in which the sealant layers of the laminate are joined together. The packaging bag 10 shown in FIG. 8 may have an easy-open line 26. As shown in FIG. 8, a notch 28 or a notch (not shown) may be formed at the outer edge of the palms together part.

The present disclosure relates to, for example, the following [1] to [19].
[1] A rigid base material comprising at least a polyolefin layer containing a polyolefin as a main component and a heteroatom-containing resin layer containing a heteroatom-containing resin as a main component, and which has been subjected to a stretching process.
[2] The rigid base material according to [1] above, wherein the heteroatom-containing resin contains at least one selected from ethylene-vinyl alcohol copolymer, polyvinyl alcohol, and polyamide.
[3] The rigid base material according to [1] or [2], wherein the rigid base material includes the polyolefin layer, the adhesive resin layer, and the heteroatom-containing resin layer in this order.
[4] The rigid base material includes the polyolefin layer containing medium density polyethylene as a main component, the adhesive resin layer, and the heteroatom-containing resin containing an ethylene-vinyl alcohol copolymer or polyamide as a main component. The rigid base material according to [3] above, comprising the layers in this order.
[5] The above [1] or [2], wherein the rigid base material includes the polyolefin layer, the adhesive resin layer, the heteroatom-containing resin layer, the adhesive resin layer, and the polyolefin layer in this order. The rigid base material described in ].
[6] The rigid base material includes the polyolefin layer containing medium density polyethylene as a main component, the adhesive resin layer, and the heteroatom-containing resin containing an ethylene-vinyl alcohol copolymer or polyamide as a main component. The rigid base material according to [5], comprising, in this order, the adhesive resin layer, the adhesive resin layer, and the polyolefin layer containing medium density polyethylene as a main component.
[7] The rigid base material according to any one of [1] to [6], wherein the heteroatom-containing resin layer has a thickness of 0.5 μm or more and 10 μm or less.
[8] The rigid base material according to any one of [1] to [7] above, which is a coextruded resin film.
[9] A printed base material comprising the rigid base material according to any one of [1] to [8] above, and a printed layer provided on one or both surfaces of the rigid base material. .
[10] A laminate comprising at least a stretched base material and a sealant layer, wherein the stretched base material is the rigid base material according to any one of [1] to [8] above, and the sealant layer A laminate containing polyolefin as a main component.
[11] The laminate according to [10], wherein the laminate includes an adhesive layer between the stretched base material and the sealant layer.
[12] The laminate according to [11], wherein the adhesive layer has a thickness of 0.1 μm or more and 2.0 μm or less.
[13] The polyolefin layer of the rigid base material is a polyethylene layer, and the sealant layer contains polyethylene as a main component, or the polyolefin layer of the rigid base material is a polypropylene layer, and the sealant layer The laminate according to any one of [10] to [12] above, which contains polypropylene as a main component.
[14] The sealant layer includes at least a first layer and a second layer, the first layer containing an ethylene/α-olefin copolymer as a main component, and the first layer containing an ethylene/α-olefin copolymer as a main component. a melting point of 112° C. or lower, the second layer contains polyethylene as a main component, a melting point of the second layer is 114° C. or higher, and one surface layer of the laminate contains polyethylene as a main component; The laminate according to any one of [10] to [13] above, which is the first layer.
[15] The laminate according to [14], wherein the first layer has a density of 0.915 g/cm ³ or less, and the second layer has a density of 0.916 g/cm ³ or more.
[16] The laminate according to any one of [10] to [15], wherein the laminate has a loop stiffness value in the MD direction of 150 mN or more.
[17] The laminate according to any one of [10] to [16], wherein the polyolefin content in the entire laminate is 80% by mass or more.
[18] A packaging bag comprising the laminate according to any one of [10] to [17].
[19] The packaging bag according to [18] above, which is a standing pouch.

Hereinafter, the rigid base material, laminate, and packaging bag of the present disclosure will be described in more detail with reference to Examples, but the rigid base material, laminate, and packaging bag of the present disclosure are not limited to the following Examples.

[Preparation of stretched base material]
The following materials were used in producing the stretched base material.
・Medium density polyethylene (MDPE)
Product name: Elite5538G, manufactured by Dow chemical company,
Density: 0.941g/cm ³ , Melting point: 129°C, MFR: 1.3g/10min・High-density polyethylene (HDPE)
Product name: Elite5960G, manufactured by Dow chemical company,
Density: 0.960 g/cm ³ , Melting point: 134°C, MFR: 0.8 g/10 min. Linear low density polyethylene (LLDPE)
Product name: Elite5400G, manufactured by Dow chemical company,
Density: 0.916 g/cm ³ , Melting point: 123°C, MFR: 1.3 g/10 minutes, Adhesive resin Product name: Admer NF557, manufactured by Mitsui Chemicals,
Maleic anhydride modified polyethylene, density: 0.920g/cm ³
・Ethylene-vinyl alcohol copolymer (EVOH)
Product name: EVAL E171B, manufactured by Kuraray,
Melting point: 165°C, density: 1.14g/cm ³ ,
MFR: 1.7 g/10 min, ethylene content: 44 mol%
・Polyamide (Ny)
Product name: 5033, manufactured by Ube Industries,
Melting point: 196°C, density: 1.14g/cm ³

<Polyethylene base material>
70 parts of MDPE and 30 parts of LLDPE were mixed to obtain a blend PE (A) with an average density of 0.934 g/cm ³ . 70 parts of MDPE and 30 parts of HDPE were mixed to obtain a blended PE (B) with an average density of 0.947 g/cm ³ . LLDPE, blend PE (A), and blend PE (B) were formed by inflation molding to form blend PE (B) layer 15 μm/blend PE (A) layer 22.5 μm/LLDPE layer 50 μm/blend PE (A) 22.5 μm. / Blend PE (B) layer Co-extrusion of 5 layers with a layer thickness ratio of 15 μm was performed to form a tube-shaped film to obtain a polyethylene film with a total thickness of 125 μm, and the tube-shaped film was folded at the nip point to form two sheets. I layered it. The obtained polyethylene film was stretched 5 times in the machine direction (MD), and one of the blended PE (B) layers was subjected to corona treatment, and then the end was slit and divided into two sheets with a thickness of 25 μm. A polyethylene base material (hereinafter also referred to as "PE base material") was obtained.

<EVOH-containing base material (A)>
MDPE (Elite5538G), adhesive resin (Admer NF557), EVOH (Eval E171B), adhesive resin (Admer NF557), and MDPE (Elite 5538G) were coextruded into a film using an inflation molding method. The film was stretched 5 times in the machine direction (MD) using a stretching device to obtain an EVOH-containing base material (A). The EVOH-containing base material (A) thus obtained includes a 7 μm thick MDPE layer, a 4 μm thick adhesive resin layer, a 2.5 μm thick EVOH layer, a 4 μm thick adhesive resin layer, and a 7.5 μm thick MDPE layer in this order.
Corona treatment was performed on one MDPE layer surface.

<EVOH-containing base material (B)>
EVOH (Eval E171B), adhesive resin (Admer NF557), and MDPE (Elite5538G) are coextruded into a film using an inflation molding method, and the resulting film is stretched 5 times in the machine direction (MD) using a stretching device. The EVOH-containing base material (B) was obtained by stretching. The EVOH-containing base material (B) thus obtained consists of an EVOH layer with a thickness of 2.5 μm, an adhesive resin layer with a thickness of 3 μm, and three MDPE layers with a total thickness of 19.5 μm in this order. Be prepared.
Corona treatment was performed on the EVOH layer surface.

<EVOH-containing layer base material (C)>
EVOH (Eval E171B), adhesive resin (Admer NF557), and MDPE (Elite5538G) are coextruded into a film using an inflation molding method, and the resulting film is stretched 5 times in the machine direction (MD) using a stretching device. The EVOH-containing base material (C) was obtained by stretching. The EVOH-containing base material (C) thus obtained comprises, in this order, an EVOH layer with a thickness of 5 μm, an adhesive resin layer with a thickness of 3 μm, and three MDPE layers with a total thickness of 17 μm.
Corona treatment was performed on the EVOH layer surface.

<Ny-containing base material (D)>
A Ny-containing base material (D) was obtained in the same manner as the EVOH-containing base material (B) except that EVOH (EVAL E171B) was changed to Ny (5033). The Ny-containing base material (D) thus obtained has a Ny layer with a thickness of 2.5 μm, an adhesive resin layer with a thickness of 3 μm, and three MDPE layers with a total thickness of 19.5 μm in this order. Be prepared.
Corona treatment was performed on the Ny layer surface.

<Other stretched base materials>
Ny base material: 15 μm thick biaxially stretched nylon base material
(Unitika, emblem ON-RT)
EVOH base material: 15 μm thick biaxially stretched EVOH base material
(Kuraray, EVAL EF-XL)

[Preparation of sealant film]
The following materials were used in making the sealant film.
・Ethylene/α-olefin copolymer (hereinafter referred to as “copolymer A”)
copolymer of ethylene and C8 olefin,
Density: 0.902g/cm ³ , MFR: 1.0g/10min,
Polymerization catalyst: metallocene catalyst/ethylene/α-olefin copolymer (hereinafter referred to as “copolymer B”)
copolymer of ethylene and C8 olefin,
Density: 0.918g/cm ³ , MFR: 0.8g/10min,
Polymerization catalyst: metallocene catalyst/ethylene/α-olefin copolymer (hereinafter referred to as “copolymer C”)
copolymer of ethylene and C8 olefin,
Density: 0.941g/cm ³ , MFR: 1.3g/10min,
Polymerization catalyst: Metallocene catalyst/high pressure low density polyethylene (LDPE)
Density: 0.919g/cm ³ , MFR: 2.0g/10min・Slip agent masterbatch (slip agent MB)
Base material: polyethylene,
Slip agent: erucic acid amide, content of slip agent: 2.0% by mass,
Density: 0.921g/cm ³ , MFR: 5.4g/10min・Anti-blocking agent masterbatch (AB agent MB)
Base material: polyethylene, anti-blocking agent: acrylic resin,
Content ratio of anti-blocking agent: 30% by mass,
Density: 0.959g/cm ³ , MFR: 2.5g/10min

<PE film (A)>
A mixture of 93 parts by mass of copolymer A, 1 part by mass of slip agent MB, and 6 parts by mass of AB agent MB was used as the first layer (sealing layer), and the second layer (intermediate layer) As a second layer (laminate layer), a mixture of 69 parts by mass of copolymer C, 30 parts by mass of LDPE, and 1 part by mass of slip agent MB was used, and 89 parts by mass of copolymer B was used as the second layer (laminate layer). Using a mixture of 10 parts by mass of LDPE and 1 part by mass of slip agent MB, the thickness of the first layer (sealing layer): second layer (intermediate layer): second layer (laminate layer) A sealant film (hereinafter also referred to as "PE film (A)") having a thickness of 130 μm was obtained by three-layer extrusion film forming at a ratio of 1:3:1.
Corona treatment was performed on the laminate layer surface of the PE film (A).

The melting point of each layer in the obtained PE film (A) was determined in accordance with JIS K7121:2012 using a differential scanning calorimeter based on the following method. As a result, the melting point of the first layer (seal layer) was 99°C, the melting point of the second layer (intermediate layer) was 122°C, and the melting point of the second layer (laminate layer) was 117°C. Regarding the density, the density of the first layer (sealing layer) is 0.906g/cm ³ , the density of the second layer (intermediate layer) is 0.934g/cm ³ , and the density of the second layer (laminate layer) is 0.906g/cm 3 . The density of was 0.918 g/cm ³ .

(Measurement of melting point)
The melting point of each layer in the sealant film was determined using a differential scanning calorimeter in accordance with JIS K7121:2012. As the differential scanning calorimeter, a thermal analyzer TA7000 series manufactured by Hitachi High-Tech Science Co., Ltd. was used. Specifically, samples of each layer were taken from the sealant film. Approximately 10 mg of the sample was placed in an aluminum cell, and heated at a heating rate of 10°C/min from 20°C to a temperature sufficiently higher than the melting point (for example, 200°C) in a nitrogen atmosphere, and at that temperature it was heated to 10°C. After holding for a minute, it was cooled to 20°C at a cooling rate of 10°C/min. This heating, holding, and cooling process was repeated once more, and the melting peak temperature of the maximum endothermic peak observed during the second heating was determined, and this was taken as the melting point.

<Other sealant films>
PE film (B): unstretched polyethylene film with a thickness of 130 μm
(Mitsui Chemicals Tohcello, TUX-MCS)

[glue]
The following adhesive was used.
Solvent-free adhesive (NSL): Manufactured by Rock Paint, 2-part curable urethane-based solvent-free adhesive, main ingredient: RN-920, curing agent: HN-920 = 1:1. The weight average molecular weight (Mw) of the polymer component contained in the base resin is in the range of 2,000 to 2,500, and the polydispersity (Mw/Mn) of the polymer component contained in the base resin is 2.0 to 2. It was in the range of 5.

[Preparation of laminate]
In the following descriptions of Examples and Comparative Examples, detailed explanations of the contents already explained regarding the already mentioned layers (for example, layer formation conditions and thickness) may be omitted as appropriate.

[Example 1]
A solvent-free adhesive is applied to the corona-treated surface of the EVOH-containing substrate (A) to form an adhesive layer with a thickness of 1 μm, and the adhesive layer surface is bonded to the corona-treated surface of the PE film (A). Ta. After bonding, aging treatment was performed at 40° C. for 4 days. A laminate was produced as described above.

[Example 2]
White ink was applied to the corona-treated surface of the EVOH-containing substrate (A) using a gravure printing machine and dried with hot air to form a white layer with a thickness of 1 μm. A solvent-free adhesive was applied to the white layer surface of the base material to form an adhesive layer with a thickness of 1 μm, and the adhesive layer surface was bonded to the corona-treated surface of the PE film (A). After bonding, aging treatment was performed at 40° C. for 4 days. A laminate was produced as described above.

[Examples 3 to 5 and Comparative Examples 1 to 3]
A laminate was produced in the same manner as in Example 2 except that the stretched base material and sealant film listed in Table 2 were used as the stretched base material and sealant film, respectively.

[Preparation of standing pouch]
Prepare two of the obtained laminates, stack them on top of each other so that the sealant layers face each other, and heat seal the two sides to form a side seal part (right) and a side seal part (left). The body was formed. Next, another laminate is folded into a V shape with the sealant layer on the outside, sandwiched from one end of the body, and heat-sealed to form a lower sealed portion (front side) and a lower sealed portion (back side). ) was formed. In this way, a standing pouch was produced. The heat sealing conditions were a temperature of 140° C., a pressure of 1 kgf/cm ² , and a duration of 1 second.

[Fragrance retention]
A standing pouch was filled with 400 ml of the content (softener), and the opening was heat-sealed to seal it. After that, the sealed standing pouch was placed in an aluminum bag, and after being cured for 5 days in an environment of 40℃ and 90RH%, the odor inside the aluminum bag was confirmed by a panel test (N=10), and the average score was given using the following scoring criteria. was calculated. An average score of 3.0 or higher was considered a pass.
(Scoring criteria)
5: Odorless 4: Slight odor 3: Some odor 2: Considerable odor 1: Odor equivalent to the contents

[Oxygen barrier property]
The oxygen permeability of the laminate was measured by the following method. Using an oxygen permeability measuring device (OX-TRAN2/20, manufactured by MOCON), set the sealant layer side of the laminate so that it is on the oxygen supply side, and measure the temperature at 23°C and relative humidity according to JIS K7126. Oxygen permeability (unit: cc/m ² ·day · atm) was measured in a 90% RH environment. A test (N=2) was conducted on two laminates, and the average value of the obtained values was taken as the oxygen permeability.

[Water vapor barrier property]
The water vapor permeability of the laminate was measured by the following method. Using a water vapor permeability measuring device (manufactured by MOCON, PERMATRAN-w 3/33), set the sealant layer side of the laminate so that it is on the water vapor supply side, and measure the temperature at 40°C in accordance with JIS K7129. The water vapor permeability (unit: g/m ² ·day) was measured in an environment with a humidity of 90% RH. A test (N=2) was conducted on two laminates, and the average value of the obtained values was taken as the water vapor permeability.

[Pressure test]
Each standing pouch was filled with air and sealed, and a load of 100 kgf x 1 minute was applied to check for breakage. Tests were conducted on 5 standing pouches (N=5).

[Drop test]
Each standing pouch was filled with 400 g of water and sealed, and the standing pouches were dropped from a height of 1 m five times horizontally and five times vertically to check for breakage. Tests were conducted on 10 standing pouches (N=10).

[Heat seal strength]
A test piece with a width of 15 mm was prepared from the heat-sealed portion of each standing pouch. The peel strength of the test piece was measured in accordance with JIS Z1707. The peel strength of a 15 mm width was measured using a tensilon universal material testing machine RTC-1530 as a measuring machine under the measurement conditions of a tensile speed of 300 mm/min. Measurements were performed on five test pieces (N=5), and the average value of the obtained values was taken as the heat seal strength.

[Tear strength]
The tear strength of each laminate in the MD direction or TD direction was measured in accordance with the Elmendorf tear method of JIS K7128-2:1998. The measuring device used was an Elmendorf tear tester (manufactured by Tester Sangyo, IM-701). A test piece was prepared by stacking 16 laminates, measurements were performed on 5 test pieces (N=5), and the average value of the values obtained by converting to the value per sheet was taken as the tear strength.

[Piercing strength]
Puncture of laminates in accordance with "2. Strength test methods" of "Specification standards for foods, additives, etc., Part 3: Utensils and containers and packaging" (Ministry of Health and Welfare Notification No. 20 of 1980) under the Food Sanitation Act. The strength was measured. A needle measuring φ1.0 mm×0.5 mmR was used to pierce the laminate at a stabbing speed of 50 mm/min, and the strength when the needle penetrated the laminate was measured. Two types of piercing were performed: piercing from the stretched base material (front) side and piercing from the sealant layer (back) side, and each measurement was performed five times (N = 5), and the average value was calculated.

[Loop stiffness evaluation]
"DA-PC" manufactured by Toyo Seiki Seisakusho 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 to obtain test pieces. A test piece whose length direction is along the MD of the laminate is referred to as an "MD test piece", and a test piece whose length direction is along the TD of the laminate is referred to as a "TD test piece". Next, both ends of the test piece were fixed between clips so that the sealant layer of the test piece was on the inside, and a circular loop with a loop length of 60 mm was formed at the center of the test piece. The obtained circular loop (width 15 mm x loop length 60 mm) was pushed in from the opposite side of the clip at a pushing speed of 3.3 mm/sec, and the measured value was defined as a loop stiffness value (mN). Measurements were performed on five test pieces (N=5), and the average value of the obtained values was taken as the loop stiffness value.

[Heat seal curve]
Prepare two laminates, cut each into a size of 100 mm x 100 mm, overlap them with their sealant layer sides facing each other, and seal one end with a heat seal machine (manufactured by Tester Sangyo, TP-701-A HEAT SEAL TESTER). ) for heat sealing. The heat sealing conditions were as follows: sealing area 10 mm x 100 mm, sealing temperature 80° C. to 190° C. (single side heating), sealing pressure 1 kgf/cm ² , and sealing time 1 second. The sealed sample was cut to a width of 15 mm to produce a test piece with a length of 100 mm (in the MD direction), a width of 15 mm, and a heat-sealed portion of 10 mm x 15 mm. Using a tensile testing machine (manufactured by Orientec, Tensilon Universal Material Testing Machine, RTC-1530), the obtained test piece was subjected to a tensile test in accordance with JIS Z1707 at 23°C and 50% RH environment. did. In the tensile test, the test piece was opened 180 degrees around the heat-sealed part, both ends of the test piece were attached to a tensile tester, and the seal strength (N/15 mm) was measured at a tensile speed of 300 mm/min. Measurements were performed on five test pieces (N=5), and the average value of the obtained values was taken as the seal strength. If sealing could not be achieved by thermal melting of the stretched base material, it was written as "impossible".

1 Rigid base material 2 Polyolefin layer 3 Adhesive resin layer 4 Hetero atom-containing resin layer 5 Laminated body 6 Adhesive layer 8 Sealant layer 10 Packaging bag 11 Upper part 12 Lower part 12a Lower seal part 13 Side part 13a Side seal part 14 Surface film 15 Back film 16 Lower film 17 Storage section 20 Spout section 20a Spout seal section 26 Easy-open line 28 Notch

Claims (19)

a polyolefin layer containing polyolefin as a main component;
At least a heteroatom-containing resin layer containing a heteroatom-containing resin as a main component,
Stretched,
Rigid base material. The rigid base material according to claim 1, wherein the heteroatom-containing resin contains at least one selected from ethylene-vinyl alcohol copolymer, polyvinyl alcohol, and polyamide. The rigid base material according to claim 1 or 2, wherein the rigid base material includes the polyolefin layer, the adhesive resin layer, and the heteroatom-containing resin layer in this order. The rigid base material includes the polyolefin layer containing medium density polyethylene as a main component, the adhesive resin layer, and the heteroatom-containing resin layer containing ethylene-vinyl alcohol copolymer or polyamide as a main component. The rigid base material according to claim 3, provided in this order. The rigid base material according to claim 1 or 2, wherein the rigid base material comprises the polyolefin layer, the adhesive resin layer, the heteroatom-containing resin layer, the adhesive resin layer, and the polyolefin layer in this order. Material. The rigid base material includes the polyolefin layer containing medium-density polyethylene as a main component, the adhesive resin layer, and the heteroatom-containing resin layer containing ethylene-vinyl alcohol copolymer or polyamide as a main component, The rigid base material according to claim 5, comprising the adhesive resin layer and the polyolefin layer containing medium density polyethylene as a main component in this order. The rigid base material according to any one of claims 1 to 6, wherein the thickness of the heteroatom-containing resin layer is 0.5 μm or more and 10 μm or less. The rigid substrate according to any one of claims 1 to 7, which is a coextruded resin film. The rigid base material according to any one of claims 1 to 8,
and a printing layer provided on one or both surfaces of the rigid substrate. A laminate comprising at least a stretched base material and a sealant layer,
The stretched base material is the rigid base material according to any one of claims 1 to 8,
The sealant layer contains polyolefin as a main component,
laminate. The laminate according to claim 10, wherein the laminate includes an adhesive layer between the stretched substrate and the sealant layer. The laminate according to claim 11, wherein the adhesive layer has a thickness of 0.1 μm or more and 2.0 μm or less. The polyolefin layer of the rigid base material is a polyethylene layer, and the sealant layer contains polyethylene as a main component, or
The polyolefin layer of the rigid base material is a polypropylene layer, and the sealant layer contains polypropylene as a main component.
The laminate according to any one of claims 10 to 12. The sealant layer is
comprising at least a first layer and a second layer,
The first layer contains an ethylene/α-olefin copolymer as a main component,
The melting point of the first layer is 112°C or less,
The second layer contains polyethylene as a main component,
The second layer has a melting point of 114° C. or higher,
one surface layer of the laminate is the first layer,
The laminate according to any one of claims 10 to 13. The density of the first layer is 0.915 g/cm ³ or less,
The density of the second layer is 0.916 g/cm ³ or more,
The laminate according to claim 14. The laminate according to any one of claims 10 to 15, wherein the laminate has a loop stiffness value in the MD direction of 150 mN or more. The laminate according to any one of claims 10 to 16, wherein the polyolefin content in the entire laminate is 80% by mass or more. A packaging bag comprising the laminate according to any one of claims 10 to 17. The packaging bag according to claim 18, which is a standing pouch.

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