CN118043204A

CN118043204A - Laminate, package, and packaged article

Info

Publication number: CN118043204A
Application number: CN202280066637.3A
Authority: CN
Inventors: 武井辽; 山田干典; 三木祐二; 田中亮太; 川崎健太郎
Original assignee: Takahashi Holdings Co ltd
Current assignee: Takahashi Holdings Co ltd
Priority date: 2021-10-06
Filing date: 2022-09-02
Publication date: 2024-05-14

Abstract

The present invention provides a laminate which is mainly formed of polyethylene and has excellent heat resistance. The laminate (10A 1) is provided with a base layer (1), an adhesive layer (3) and a sealant layer (2) in this order, wherein the base layer (1) and the sealant layer (2) comprise polyethylene, and the probe lowering temperature of the base layer (1) is 180 ℃ or higher.

Description

Laminate, package, and packaged article

Technical Field

The present invention relates to a laminate, a package, and a packaged article.

Background

Various properties are required for packaging materials used for packages such as packaging bags, depending on the application. The characteristics required for the packaging material are, for example, strength required for the package, suitability for making bags, suitability for printing, suitability for transportation, and preservability of the contents. In order to meet these demands, a packaging material obtained by compounding a plurality of synthetic resin films having different characteristics is generally used.

For example, patent document 1 describes a packaging material in which a resin film made of polyethylene is adhered to a resin film made of polyester, polyamide, or the like.

Patent document 2 describes a multilayer film in which a gas barrier layer formed by applying a dispersion liquid containing an inorganic lamellar compound and a water-soluble polymer to at least one surface of a base layer made of a thermoplastic resin, a top coat layer containing a cationic resin and a resin having a hydroxyl group, an adhesive layer, and a sealant layer are laminated in this order. This document describes a specific example in which a nylon film is used as a base material layer and a linear low-density polyethylene film is used as a sealant layer.

In recent years, as the demand for building a circulating society increases, packaging materials having high recycling properties are demanded. However, as described above, the conventional packaging material is made of a different type of resin material. It is difficult to separate these resin materials from each other.

In addition, it is considered that the recycling property is high when the proportion of the main resin contained in the packaging material is 90 mass% or more. Many of the conventional packaging materials contain a plurality of resin materials as described above, and do not satisfy the above criteria.

Therefore, many of the packaging materials cannot be recycled, which is the current situation.

Patent document 3 describes a laminate in which a stretched film made of polyethylene is used as a base material, an adhesive layer and a heat-seal layer made of polyethylene are provided thereon, and a vapor deposition layer is provided between the base material and the adhesive layer and between the heat-seal layer and the adhesive layer. This document describes that the laminate has sufficient strength, heat resistance and barrier properties for use as a packaging material, and is excellent in recycling properties.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2009-202519

Patent document 2: japanese patent laid-open No. 2009-241359

Patent document 3: japanese patent laid-open No. 2020-055157

Disclosure of Invention

The purpose of the present invention is to provide a laminate which is formed mainly of polyethylene and has excellent heat resistance.

According to one aspect of the present invention, there is provided a laminate comprising, in order, a base layer, an adhesive layer, and a sealant layer, wherein the base layer and the sealant layer comprise polyethylene, and the probe lowering temperature of the base layer is 180 ℃.

According to another aspect of the present invention, there is provided the laminate according to the above aspect, wherein the probe lowering temperature of the base material layer is 220 ℃ or lower.

According to still another aspect of the present invention, there is provided the laminate according to any one of the above aspects, further comprising an intermediate layer comprising polyethylene and existing between the base material layer and the sealant layer.

According to still another aspect of the present invention, there is provided the laminate according to the above aspect, wherein the probe-lowering temperature of the intermediate layer is 180 ℃ or lower.

Or according to still another aspect of the present invention, there is provided the laminate according to the above aspect, wherein the probe lowering temperature of the intermediate layer is 140 ℃ or higher and less than 180 ℃.

Or according to still another aspect of the present invention, there is provided the laminate according to the above aspect, wherein the probe-lowering temperature of the intermediate layer is 180 ℃ or higher.

According to still another aspect of the present invention, there is provided the laminate according to the above aspect, wherein the probe lowering temperature of the intermediate layer is 220 ℃ or lower.

According to still another aspect of the present invention, there is provided the laminate according to any one of the above aspects, further comprising a protective layer which is an outermost layer facing the sealant layer with the base material layer interposed therebetween.

According to still another aspect of the present invention, there is provided the laminate according to the above aspect, wherein the protective layer is formed of a thermosetting resin.

According to still another aspect of the present invention, there is provided the laminate according to any one of the above aspects, wherein the base material layer is a biaxially stretched film.

Or according to still another aspect of the present invention, there is provided the laminate according to any one of the above aspects, wherein the base material layer is a uniaxially stretched film.

According to still another aspect of the present invention, there is provided the laminate according to any one of the above aspects, further comprising a gas barrier layer interposed between the base material layer and the sealant layer.

According to still another aspect of the present invention, there is provided the laminate according to any one of the above aspects, wherein the adhesive layer is gas-barrier.

According to still another aspect of the present invention, there is provided the laminate according to any one of the above aspects, wherein the sealant layer is white.

According to still another aspect of the present invention, there is provided the laminate according to any one of the above aspects, wherein the proportion of polyethylene is 90 mass% or more.

According to still another aspect of the present invention, there is provided a package comprising the laminate according to any one of the above aspects.

According to still another aspect of the present invention, there is provided the package according to the above aspect, which is a stand-up pouch.

According to a further aspect of the present invention there is provided a packaged article comprising a package according to any one of the above aspects and contents contained therein.

According to the present invention, a laminate which is mainly formed of polyethylene and is excellent in heat resistance can be provided.

Drawings

Fig. 1 is a cross-sectional view schematically showing a laminate according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view schematically showing a modification of the laminate shown in fig. 1.

Fig. 3 is a cross-sectional view schematically showing a laminate according to a second embodiment of the present invention.

Fig. 4 is a cross-sectional view schematically showing a modification of the laminate shown in fig. 3.

Fig. 5 is a cross-sectional view schematically showing a laminate according to a third embodiment of the present invention.

Fig. 6 is a cross-sectional view schematically showing a first modification of the laminate shown in fig. 5.

Fig. 7 is a cross-sectional view schematically showing a second modification of the laminate shown in fig. 5.

Fig. 8 is a cross-sectional view schematically showing a laminate according to a fourth embodiment of the present invention.

Fig. 9 is a cross-sectional view schematically showing a laminate according to a fifth embodiment of the present invention.

Fig. 10 is a cross-sectional view schematically showing a first modification of the laminate shown in fig. 9.

Fig. 11 is a cross-sectional view schematically showing a second modification of the laminate shown in fig. 9.

Fig. 12 is a cross-sectional view schematically showing a laminate according to a sixth embodiment of the present invention.

Fig. 13 is a view schematically showing a packaged article according to a seventh embodiment of the present invention.

Fig. 14 is a view schematically showing a packaged article according to an eighth embodiment of the present invention.

Fig. 15 is a view schematically showing a packaged article according to a ninth embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. The embodiments described below embody any of the above aspects. The matters described below may be incorporated in each of the above aspects singly or in combination.

The embodiments described below are examples of configurations for embodying the technical idea of the present invention, and the technical idea of the present invention is not limited by the materials, shapes, structures, and the like of the following constituent members. The technical idea of the present invention can be variously modified within the technical scope defined in the claims described in the claims.

In addition, for elements having the same or similar functions, the same reference numerals are given to the drawings referred to below, and the repetitive description is omitted. Therefore, the matters mentioned in one embodiment are applicable to other embodiments unless otherwise specified. The drawings are schematic, and the relationship between the dimensions in a certain direction and the dimensions in other directions, the relationship between the dimensions of a certain member and the dimensions of other members, and the like may be different from the actual situation.

< 1> First embodiment

< 1.1 > Laminate

The laminate 10A1 shown in fig. 1 includes, in order, a base material layer 1, a print layer 4, an adhesive layer 3, and a sealant layer 2.

The polyethylene content of the laminate 10A1 is 90 mass% or more. Here, the proportion of polyethylene in the laminate refers to the proportion of the total amount of polyethylene in the total amount of resin materials of the respective layers constituting the laminate. By setting the polyethylene ratio to 90 mass% or more, high recycling properties can be achieved.

< 1.2 > Substrate layer

The substrate layer 1 comprises polyethylene. Preferably, the substrate layer 1 is formed of polyethylene. The probe-lowering temperature of the substrate layer 1 is 180 ℃ or higher. The upper limit of the probe-lowering temperature of the substrate layer 1 is not particularly limited. Preferably 250℃or lower, more preferably 220℃or lower.

As described above, the probe-down temperature of the base material layer 1 is high. The high temperature drop under the probe means excellent heat resistance as a base material. The excellent heat resistance teaches that the molecular chains constituting the substrate layer form a regular arrangement. Examples of the formation of the regular arrangement include formation of crystals (spherulites) as a primary structure and oriented crystallization as a secondary structure. In particular, the formation of the secondary structure represented by the latter oriented crystallization can be expected to improve heat resistance, and also impact resistance and puncture resistance can be expected due to the regularity of the molecular arrangement.

The probe-down temperature can be adjusted by using the film-forming conditions such as the density of the resin used, the type of the comonomer, the molecular weight distribution, the thermal history, and the film-forming method, in addition to the stretching conditions such as the stretching ratio of the base layer.

The polyethylene contained in the base material layer 1 may be a homopolymer of ethylene or a copolymer of ethylene and another monomer. When the polyethylene is a copolymer of ethylene and another monomer, the proportion of ethylene in the copolymer is, for example, 80mol% or more.

Other monomers are, for example, alpha-olefins. According to one example, the carbon number of the alpha-olefin is in the range of 3 to 20. Such alpha-olefins are, for example, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, or 6-methyl-1-heptene.

The polyethylene may also be a copolymer of ethylene and one of vinyl acetate and an acrylate.

The base material layer 1 is, for example, high Density Polyethylene (HDPE), medium Density Polyethylene (MDPE), low Density Polyethylene (LDPE), linear Low Density Polyethylene (LLDPE), or ultra low density polyethylene (VLDPE).

Here, the density of the high-density polyethylene is 0.942g/cm ³ or more, the density of the medium-density polyethylene is 0.930g/cm ³ or more and less than 0.942g/cm ³, the density of the low-density polyethylene is 0.910g/cm ³ or more and less than 0.930g/cm ³, the density of the linear low-density polyethylene is 0.910g/cm ³ or more and less than 0.930cm ³, and the density of the ultra-low-density polyethylene is less than 0.910g/cm ³.

Further, the density was determined by using a method based on JIS K7112:1999, values obtained by the method of 1999.

The polyethylene contained in the substrate layer 1 may also be biomass-derived polyethylene. As biomass-derived polyethylene, for example, green polyethylene (Green Polyethylene, manufactured by Braskem corporation) can be used.

Alternatively, the polyethylene contained in the base material layer 1 may be a polyethylene obtained by subjecting the base material layer to cyclic regeneration by mechanical cyclic regeneration. Here, the mechanical recycling is to crush a recovered polyethylene film or the like, then to alkali-wash the crushed film, to remove dirt and foreign matter on the film surface, and then to dry the film at a high temperature under reduced pressure to diffuse the contaminant remaining in the film, thereby purifying the polyethylene film.

Alternatively, the polyethylene contained in the base material layer 1 may be recycled polyethylene by chemical recycling.

The melting point of the base material layer 1 is preferably in the range of 100 to 140 ℃, more preferably in the range of 120 to 140 ℃. Further, the melting point is a value obtained by a method based on JIS K7121-1987.

The probe lowering temperature of the base material layer 1 is a value obtained by a measurement method described later on the surface of the base material layer 1 opposite to the surface facing the sealing agent layer 2. The method for measuring the probe-drop temperature will be described in detail later.

The base material layer 1 may be an unstretched film or a stretched film. The substrate layer 1 is preferably a stretched film. When the base material layer 1 is a stretched film, heat resistance and strength are particularly excellent. In addition, the elongation of the base material layer 1 is reduced, and the printing suitability is improved. In addition, in the present specification, the term "film" does not include the concept of thickness.

When the base material layer 1 is a stretched film, the base material layer 1 may be a uniaxially stretched film or a biaxially stretched film. When a uniaxially stretched film is used as the base layer 1, heat resistance at the time of bag making, that is, sealability described later is improved. When a biaxially stretched film is used as the base layer 1, the dropping strength of the packaged article using the laminate 10A as a packaging material is improved.

The stretched film can be distinguished by performing in-plane measurement by a wide-angle X-ray diffraction method as described below. The X-ray diffraction pattern obtained by this measurement contains information on the degree of orientation of the molecular chains present on the film surface. An example of the measurement method is shown.

First, out-of-plane measurement was performed by a parallel beam method using a wide-angle X-ray diffraction apparatus manufactured by Rigaku corporation. An X-ray diffraction pattern of the film to be measured is obtained by performing 2θ/θ scanning in a range of 10 ° to 30 °. The cukα ray was used as the X-ray, and the X-ray parallelized by the multilayer mirror was incident on the base material layer 1. The light receiving unit uses a scintillation detector mounted with a flat collimator.

The peak area of the crystalline component and the halo pattern area of the amorphous component were obtained from the obtained X-ray diffraction pattern, and the ratio of the peak area of the crystalline component to the sum of these areas was calculated as the crystallization degree.

When the film to be measured has a plurality of layers, the crystallinity of any one of the layers on the outermost surface of the film is measured.

When the film to be measured is a polyethylene film, a halation pattern of a wide amorphous component and a peak of a crystalline component corresponding to 2 points of the (110) plane and the (200) plane is observed when scanning is performed in a range of 10 ° to 30 °.

In the case of discriminating between a uniaxially stretched film and a biaxially stretched film, the in-plane measurement by the X-ray diffraction method can be used as described above. In the in-plane measurement, the X-ray incidence angle θ and the angle 2θ at which the diffracted X-rays are detected by the detector are fixed to the angle θ and the angle 2θ at which the diffraction peak corresponding to a specific crystal plane, for example, the diffraction peak corresponding to the (110) plane of the polyethylene film is detected in the out-of-plane measurement, and in this state, the film to be measured is scanned in the in-plane direction to obtain the diffraction pattern.

When the uniaxially stretched film uniaxially stretched in the Machine Direction (MD) is subjected to in-plane measurement, a diffraction pattern having a sharp diffraction peak corresponding to the (110) plane at a position where the angle 2θ is about ±90° can be obtained when the MD direction is defined as 0 °. On the other hand, in the case of a biaxially stretched film, the higher order structure obtained by uniaxial stretching is disturbed by the second stretching, and the anisotropy is lowered, so that a diffraction pattern having sharp diffraction peaks corresponding to the (110) plane cannot be obtained. Thus, the in-plane measurement can be exemplified as a method of distinguishing a uniaxially stretched film and a biaxially stretched film from each other.

As described above, when the polymer film is uniaxially stretched, the polymer film exhibits a higher order structure. This higher order structure is known as the tandem (Shish-Kebab) structure. The tandem structure is formed of Shish structure as extended chain crystal and Kebab structure as plate crystal. In the uniaxially stretched film, the higher order structures are arranged in a high order parameter, and therefore, the X-ray diffraction pattern obtained by the above measurement for the uniaxially stretched film becomes to include sharp diffraction peaks. That is, when the uniaxially stretched film is measured as described above, a significant diffraction peak appears. In addition, "distinct diffraction peak" refers to a diffraction peak having a half-width of less than 10 °.

In the production of biaxially stretched films, stretching is performed in a specific direction, followed by stretching in a direction perpendicular to the previous direction. Thus, although the above-described higher order structure is generated by the first stretching, the higher order structure is disturbed by the second stretching. Thus, when the biaxially stretched film is subjected to the above measurement, the diffraction peak becomes broader in the X-ray diffraction pattern obtained thereby. That is, when the biaxially stretched film was subjected to the above measurement, no significant diffraction peak was observed.

As described above, the X-ray diffraction patterns obtained by the above measurement are different in the uniaxially stretched film and the biaxially stretched film. Therefore, it is possible to distinguish whether the stretched film is a uniaxially stretched film or a biaxially stretched film based on this.

The haze of the base material layer 1 is preferably 20% or less, more preferably 10% or less. Further, haze was obtained by using a film according to JIS K7136: 2000.

The thickness of the base material layer 1 is preferably in the range of 10 μm to 200 μm. The thickness of the base material layer 1 is, for example, in the range of 10 μm to 50 μm, or in the range of 15 μm to 50 μm, or in the range of 12 μm to 35 μm. When the base material layer 1 is too thin, the strength of the laminate 10A1 tends to decrease. When the base material layer 1 is too thick, the processing suitability of the laminate 10A1 tends to be low.

The substrate layer 1 is preferably subjected to a surface treatment. By this treatment, the adhesion between the base material layer 1 and the layer adjacent to the base material layer 1 can be improved.

The method of surface treatment is not particularly limited. Examples of the surface treatment include corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen and/or nitrogen, physical treatment such as arc discharge treatment, and chemical treatment such as oxidation treatment using chemicals.

The substrate layer 1 may further comprise additives. Examples of the additives include a crosslinking agent, an antioxidant, an antiblocking agent, a lubricant (sliding) agent, an ultraviolet absorber, a light stabilizer, a filler, a reinforcing agent, an antistatic agent, a pigment, and a modifying resin.

< 1.3 > Sealant layer

The sealant layer 2 faces the base material layer 1. The sealant layer 2 comprises polyethylene. Preferably, the sealant layer 2 is formed of polyethylene.

The sealant layer 2 may be transparent or opaque. In the latter case, the sealant layer 2 is preferably white. The sealant layer 2 is a transparent laminate 10A, and the contents are easily seen when it is used in a package. The sealant layer 2 is an opaque laminate 10A, and when used in a package, the contents do not interfere with the visibility of the image displayed by the print layer 4. In particular, the white sealant layer 2 improves the visibility of the image displayed by the printed layer 4.

< 1.4 > Print layer

The print layer 4 is provided on the surface of the base material layer 1 facing the sealant layer 2, that is, on the back surface of the base material layer 1.

The printing ink used for the printing layer 4 is not particularly limited as long as it has adhesion to polyethylene. The print layer 4 is formed of, for example, an ink in which various pigments, extender pigments, plasticizers, drying agents, stabilizers, and other additives are added to a conventionally used ink binder resin such as urethane-based, acrylic-based, nitrocellulose-based, rubber-based, and vinyl chloride-based ink. As the printing ink, a biomass-derived ink is preferably used. As the ink, a biomass ink containing a biomass-derived material can also be preferably used. In addition, light-shielding inks can also be used preferably. Examples of the light-shielding ink include white ink, black ink, silver ink, and dark brown ink.

As the printing method, for example, a known printing method such as an offset printing method, a gravure printing method, a flexography method, and a screen printing method, or a known coating method such as roll coating, air knife coating, and gravure coating can be used.

The print layer 4 may be provided at any position as long as it is between the base material layer 1 and the sealant layer 2. For example, when the laminate 10A further includes an intermediate layer described later, the printed layer 4 may be provided on either side of the intermediate layer. That is, the printed layer 4 may be provided between any layers. The print layer 4 may be provided on the surface of the base material layer 1 or may be omitted. The laminate 10A may further include a plurality of printed layers.

< 1.5 > Adhesive layer

The adhesive layer 3 adheres the base material layer 1 provided with the print layer 4 and the sealant layer 2. As the adhesive for forming the adhesive layer 3, for example, a general adhesive for dry lamination is used.

The adhesive layer 3 contains at least 1 adhesive. The adhesive may be a one-component curable adhesive, a two-component curable adhesive, or a non-curable adhesive. The adhesive may be a solvent-free adhesive or a solvent-based adhesive.

Examples of the adhesive include polyether adhesives, polyester adhesives, silicone adhesives, epoxy adhesives such as polyamine adhesives, urethane adhesives, rubber adhesives, vinyl adhesives, silicone adhesives, epoxy adhesives, phenol adhesives, and olefin adhesives. It is also preferable to use a binder containing a biomass component. The adhesive is preferably a polyamine-based adhesive or a urethane-based adhesive having gas barrier properties.

The adhesive layer 3 may be a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphoric acid-modified compound. The adhesive layer 3 can further improve the oxygen barrier property and the water vapor barrier property of the laminate 10 A1.

The thickness of the adhesive layer 3 is preferably in the range of 0.1 μm to 20 μm, more preferably in the range of 0.5 μm to 10 μm, and still more preferably in the range of 1 μm to 5 μm.

The adhesive layer 3 can be formed by applying a conventionally known method such as a direct gravure roll coating method, a kiss coating method, a reverse roll coating method, a spray method, or a transfer roll coating method to the sealing agent layer 2 and drying the same.

Method for measuring probe dropping temperature of less than 1.6

The method for measuring the probe drop temperature will be described below.

The probe-down temperature refers to a temperature obtained by measuring the up-down behavior of the probe, and is a temperature obtained by performing a local thermal analysis.

An Atomic Force Microscope (AFM) having a nanothermal microscope constituted by a cantilever (probe) having a heating mechanism is used for measuring the probe drop temperature. In measurement, a solid resin substrate is first fixed as a sample on a sample stage. Next, the cantilever is brought into contact with the sample surface, and a voltage is applied to the cantilever while a constant force (touch pressure) is applied thereto in a contact mode to heat the sample surface. Thus, the sample surface thermally expands and the cantilever rises. When the temperature of the cantilever is further raised by increasing the voltage, the surface of the sample is softened and the hardness is greatly changed. At this time, the cantilever is lowered and immersed in the sample. The probe-down temperature is calculated from the relationship between the displacement of the cantilever and the voltage during this period. That is, the temperature at which the position of the cantilever is changed sharply is the softening point of the sample. The temperature obtained by converting the voltage at this time is a softening temperature, i.e., a probe-descent temperature.

By performing such measurement, the softening temperature of the nanoscale region can be understood, not the average softening temperature of the entire sample. Specifically, the softening temperature of the surface region of the sample can be known.

As an atomic force microscope, MPF-3D-SA (trade name) manufactured by Oxford Instruments Co., ltd., ztherm system (trade name) was used. The atomic force microscope is not particularly limited to this apparatus, and Nano THERMAL ANALYSIS (trade name) series and nanoIR (trade name) series manufactured by Bruker Japan can be used. Furthermore, nano THERMAL ANALYSIS (trade name) may be attached to an atomic force microscope of another manufacturer for measurement.

As the cantilever, AN2-200 (trade name) manufactured by Anaxis Instruments Co., ltd. The cantilever is not particularly limited thereto, and other cantilevers may be used as long as they can sufficiently reflect laser light and can apply voltage.

The voltage applied to the cantilever is preferably 1V to 10V depending on the resin to be measured, etc., and more preferably 3V to 8V in order to reduce the damage of the sample and to measure the spatial resolution more highly.

The temperature range in which measurement can be performed also varies depending on the resin to be measured, and generally, the measurement start temperature is about 25 ℃ or more and the measurement end temperature is about 400 ℃ or less at normal temperature. The temperature range in which the probe temperature is calculated is preferably 25℃to 300 ℃.

In the measurement of the temperature drop of the probe, as described above, the pressure of the cantilever is made constant, and heat is applied to the sample. In order to apply the touch pressure, the cantilever needs to be brought into contact with the sample, but the touch pressure needs to be such that the surface of the sample is not damaged. The cantilever preferably has a spring constant of 0.1 to 3.5N/m, and preferably has a spring constant of 0.5 to 3.5N/m for measurement in both the tapping mode and the contact mode. The contact pressure is preferably 0.1 to 3.0V.

The temperature rise rate (voltage rise rate) of the cantilever varies depending on the heating mechanism or the like provided in the cantilever, and is preferably in the range of from 0.1V/sec to 10V/sec. The temperature rise rate is more preferably 0.2V/sec or more and 5V/sec or less.

As described above, when the sample surface softens, the cantilever intrudes into the sample and descends. The penetration amount of the cantilever is preferably 3 to 500nm because it is required to have a size capable of recognizing the peak top of the softening curve. When the penetration amount is large, the cantilever (probe) may be broken, and therefore, the penetration amount of the cantilever is more preferably 5 to 100nm.

The probe descent start point or probe descent temperature may be calculated by approximating the expanded curve and the softened curve with functions, respectively, as necessary, and calculating the intersection point of the approximated curves. Alternatively, an analytical method using the shifted peak top as the probe-drop start point or the probe-drop temperature may be used. Alternatively, the probe-down start point or probe-down temperature may be calculated from the voltage at which the displacement reaches a specific value from the steady state.

As described above, the probe-descent temperature is converted from the voltage. A standard curve (correction curve) can be used for the conversion. In order to obtain a correct probe-down temperature, a calibration curve is prepared, for example, after measurement of a sample is performed. As the calibration samples, four types of polycaprolactone (melting point: 55 ℃ C.), low density polyethylene (LDPE, melting point: 110 ℃ C.), polypropylene (PP, melting point: 164 ℃ C.), and polyethylene terephthalate (PET, melting point: 235 ℃ C.) were used. For each of the calibration samples, measurement was performed 2 times or more by changing the measurement position, and the average value of the voltages corresponding to the start points of probe descent was calculated from the measurement results. Further, a standard curve (calibration curve) was prepared from the average value of the voltages obtained for all the calibration samples and their melting points. In this calibration curve, the probe-descent temperature is obtained by referring to the voltage obtained for the sample.

Effect of < 1.7 >

The laminate 10A1 is excellent in heat resistance. This will be described below.

The manufacturing of the packaging bag generally includes the steps of: the sealant layers of the laminate are brought into contact with each other, and the contact portions are held by a jig and pressure and heat are applied, so that the contact portions are thermally fusion bonded (heat-sealed). The fixture of the heat sealer is at a high temperature and the surface of the substrate layer that directly contacts the fixture is exposed to the high temperature. As a result, when a polyethylene having poor heat resistance is used for the base material layer, the surface of the base material layer may be affected by heat and may adhere to a jig. Therefore, conventional laminates using polyethylene for the base material layer have problems of narrow conditions suitable for the bag-making temperature and poor productivity.

The present inventors have measured the probe-lowering temperature for various polyethylenes and have found that when the probe-lowering temperature of the base material layer 1 is 180 ℃ or higher, the base material layer 1 exhibits excellent heat resistance, and therefore the laminate 10A1 also exhibits excellent heat resistance, resulting in particularly good heat sealing suitability.

In the laminate 10A1, polyethylene generally called a heat-resistant material is used as the base layer 1. However, by setting the probe lowering temperature of the base material layer 1 to 180 ℃ or higher, the temperature range of heat sealing for bag making is widened, and no reduction in productivity occurs.

Further, the polyethylene content of the laminate 10A1 is 90 mass% or more. Therefore, the laminate 10A1 is also excellent in recycling property.

< 1.8 > Modification example

The laminate 10A1 may be variously modified.

Fig. 2 is a cross-sectional view schematically showing a modification of the laminate shown in fig. 1. The laminate 10A2 shown in fig. 2 is the same as the laminate 10A1 except that it further includes an inorganic compound layer 5 existing between the base material layer 1 and the print layer 4. The inorganic compound layer 5 is a thin film formed of an inorganic compound, for example, an inorganic oxide such as alumina or silica, and functions as a gas barrier layer that inhibits permeation of oxygen or water vapor. The laminate 10A2 may further include the coating layer described in the second embodiment in place of the inorganic compound layer 5. Alternatively, the laminate 10A2 may further include the coating layer between the inorganic compound layer 5 and the adhesive layer 3. The coating layer or the combination of the coating layer and the inorganic compound layer 5 may also function as a gas barrier layer.

The laminate 10A2 also has excellent heat resistance. Further, since the inorganic compound layer 5 is substantially transparent, even if the inorganic compound layer 5 is provided between the base material layer 1 and the print layer 4, an image displayed on the print layer 4 can be seen from the front surface side. Further, the laminate 10A2 is also excellent in recycling property.

In order to impart light-shielding properties, a metal deposition layer may be provided between the base material layer 1 and the sealant layer 2 in the laminated bodies 10A1 and 10 A2. When the laminate further includes an intermediate layer described later, a metal deposition layer may be provided on any one surface of the intermediate layer. The metal deposition layer may be an aluminum deposition layer.

In addition, although it has been described that the sealant layer 2 may be opaque, the substrate layer 1 may also be opaque. For example, the base material layer 1 may be white. When the laminate further includes an intermediate layer described later, the intermediate layer may be opaque. For example, the intermediate layer may also be white.

< 2 > Second embodiment

< 2.1 > Laminate

The laminate 10B1 shown in fig. 3 is the same as the laminate 10A1 except that it further includes a protective layer 6 provided on the surface of the base material layer 1 and a coating layer 7 existing between the base material layer 1 and the print layer 4.

< 2.2 > Protective layer

The protective layer 6 is the outermost layer facing the sealant layer 2 with the base material layer 1 interposed therebetween. Here, the protective layer 6 covers the surface of the base material layer 1.

The protective layer 6 is formed of a thermosetting resin according to an example. That is, the protective layer 6 is a thermosetting resin layer. The cured product of the thermosetting resin is not particularly limited as long as it has heat resistance. As the thermosetting resin, for example, a urethane resin, a polyester resin, a polyamide resin, an acrylic resin, and an epoxy resin may be used as a monomer or as a composite.

The protective layer 6 preferably contains a water-soluble polymer, and preferably also contains an organic-inorganic composite layer containing an organometallic compound.

Examples of the water-soluble polymer include polysaccharides such as polyvinyl alcohol and starch-methyl cellulose-carboxymethyl cellulose, and hydroxyl-containing polymers such as acrylic polyols. The protective layer 6 preferably contains a polyvinyl alcohol-based hydroxyl group-containing polymer that can be contained in the coating layer 7 in one embodiment.

The protective layer 6 preferably contains, as the organometallic compound, at least one of a metal alkoxide, a hydrolysate of the metal alkoxide, and a reaction product of the metal alkoxide or a hydrolysate thereof. Examples of the metal alkoxide include tetraethoxysilane [ Si (OC ₂H₅)₄ ] and triisopropoxyaluminum [ Al (OC ₃H₇)₃) ] represented by the general formula M (OR) _n.

In addition, the protective layer 6 preferably further contains at least one of a silane coupling agent, a hydrolysate of the silane coupling agent, and a reaction product of the silane coupling agent or the hydrolysate of the silane coupling agent as the organometallic compound.

The protective layer 6 may be formed using a coating liquid for forming the coating layer 7.

The protective layer 6 reduces thermal damage to the laminate surface during heat sealing. When the thickness of the protective layer 6 is 0.3 μm or more, the effect of reducing thermal damage is particularly large. However, when the protective layer 6 is thickened, insufficient drying of a coating film formed of a thermosetting resin or a decrease in productivity is liable to occur. Therefore, the thickness of the protective layer 6 is preferably 3 μm or less, more preferably less than 3 μm.

< 2.3 > Coating layer

The coating layer 7 functions as a barrier layer that inhibits permeation of oxygen or water vapor. When high barrier properties are not required, the coating layer 7 may be omitted.

The coating layer 7 may be formed by coating, for example. In this case, a coating liquid containing a resin such as polyvinyl alcohol (PVA), an ethylene-vinyl alcohol copolymer, an ethylene-vinyl acetate copolymer, polyvinylidene chloride, polyacrylonitrile, and an epoxy resin can be used. The coating liquid may further contain additives such as organic or inorganic particles, lamellar compounds, and curing agents.

Or the coating layer 7 is a film containing a hydroxyl group-containing polymer and an organosilicon compound. The coating layer 7 may be, for example, an organic-inorganic composite layer containing a reaction product of hydrolysis and dehydration condensation of alkoxide and a water-soluble polymer. The organic-inorganic composite layer may further comprise a reaction product of a silane coupling agent.

Examples of the alkoxide used for forming the organic-inorganic composite layer include tetraethoxysilane [ Si (OC ₂H₅)₄ ] and triisopropoxyaluminum [ Al (OC ₃H₇)₃) ] represented by the general formula M (OR) _n.

The total content of the alkoxide, the hydrolysate thereof, or the reaction product thereof in the coating liquid used for forming the organic-inorganic composite layer may be 40 mass% or more, may be 50 mass% or more, or may be 65 mass% or more, for example, from the viewpoint of oxygen barrier property. The total content of the alkoxide, the hydrolysate thereof, or the reaction product thereof in the coating liquid may be, for example, 70 mass% or less.

The water-soluble polymer contained in the organic-inorganic composite layer is not particularly limited, and examples thereof include polysaccharides such as polyvinyl alcohol and starch-methylcellulose-carboxymethylcellulose, and hydroxyl-containing polymers such as acrylic acid polyol. From the viewpoint of further improving the oxygen barrier property, the water-soluble polymer preferably contains a polyvinyl alcohol-based water-soluble polymer. The number average molecular weight of the water-soluble polymer is, for example, 40000 to 180000.

The polyvinyl alcohol-based water-soluble polymer contained in the organic-inorganic composite layer can be obtained by, for example, saponifying polyvinyl acetate (including partial saponification). The water-soluble polymer may have several tens% of acetic acid groups or may have only several% of acetic acid groups.

The content of the water-soluble polymer in the coating liquid used for forming the organic-inorganic composite layer may be 15 mass% or more, or 20 mass% or more, for example, from the viewpoint of oxygen barrier property. The content of the water-soluble polymer in the coating liquid may be 50 mass% or less, or 45 mass% or less, for example, from the viewpoint of oxygen barrier property.

The silane coupling agent used for the organic-inorganic composite layer includes a silane coupling agent having an organic functional group. Examples of such silane coupling agents include ethyltrimethoxysilane, vinyltrimethoxysilane, gamma-chloropropylmethyldimethoxysilane, gamma-chloropropyltrimethoxysilane, glycidoxypropyl trimethoxysilane, gamma-methacryloxypropyl methyldimethoxysilane, and the like. The silane coupling agent, the hydrolysate thereof and the reaction product thereof selected from these may be used alone in 1 kind or in combination in 2 or more kinds.

As the silane coupling agent, those having an epoxy group as an organic functional group are preferably used. Examples of the silane coupling agent having an epoxy group include gamma-glycidoxypropyl trimethoxysilane and beta- (3, 4-epoxycyclohexyl) ethyl trimethoxysilane. The silane coupling agent having an epoxy group may also have an organic functional group other than an epoxy group such as a vinyl group, an amino group, a methacryl group, or a urea group. The silane coupling agent, the hydrolysate thereof and the reaction product thereof selected from these may be used alone in 1 kind or in combination in 2 or more kinds.

The silane coupling agent having an organic functional group, the hydrolysate thereof, or the reaction product thereof can further improve the oxygen barrier property of the coating layer and the adhesion to the adjacent layer by the interaction of the organic functional group and the water-soluble polymer hydroxyl group. In particular, when the silane coupling agent, the hydrolysate thereof, or the reaction product thereof has an epoxy group, and the water-soluble polymer is polyvinyl alcohol (PVA), the oxygen barrier property and the adhesion to the adjacent layer can be further improved by the interaction between the epoxy group and the hydroxyl group of the PVA.

The total content of the silane coupling agent, the hydrolysate thereof, and the reaction product thereof in the coating liquid used for forming the organic-inorganic composite layer may be 1 mass% or more, or 2 mass% or more, for example, from the viewpoint of oxygen barrier property. The total content of the silane coupling agent, the hydrolysate thereof, and the reaction product thereof in the coating liquid may be 15 mass% or less, or 12 mass% or less, for example, from the viewpoint of oxygen barrier property.

The thickness of the coating layer is preferably 50nm to 1000nm, more preferably 100nm to 500 nm. When the thickness of the coating layer 7 is 50nm or more, a more sufficient gas barrier property tends to be obtained, and when it is 1000nm or less, a sufficient flexibility tends to be maintained.

Effect of < 2.4 >

The laminate 10B1 includes the protective layer 6. As described above, the protective layer 6 reduces heat damage at the time of heat sealing of the surface of the laminate. Therefore, the laminate 10B1 can achieve more excellent heat resistance, in particular, more excellent heat seal suitability. Therefore, when the above-described structure is adopted for the laminate 10B1, the temperature range of the heat seal performed for bag making becomes wider, and the productivity is more unlikely to be lowered.

That is, the heat resistance of the laminate 10B1 is more excellent. Further, the laminate 10B1 is also excellent in recycling property.

< 2.5 > Modification example

The laminate 10B1 may have various modifications.

Fig. 4 is a cross-sectional view schematically showing a modification of the laminate shown in fig. 3. The laminate 10B2 shown in fig. 4 is similar to the laminate 10B1 except that the inorganic compound layer 5 is further included between the base material layer 1 and the coating layer 7.

In the laminate 10B2, the combination of the coating layer 7 and the inorganic compound layer 5 functions as a barrier layer. The coating layer 7 may be omitted from the laminate 10B 2.

The laminate 10B2 is also excellent in heat resistance, similar to the laminate 10B 1. Further, the laminate 10B2 is also excellent in recycling property.

< 3 > Third embodiment

< 3.1 > Laminate

The laminate 10C1 shown in fig. 5 is similar to the laminate 10A1 except for the following matters. That is, the laminate 10C1 does not include the printed layer 4, and further includes the intermediate layer 8. The laminate 10C1 includes a first adhesive layer 3A and a second adhesive layer 3B instead of the adhesive layer 3.

< 3.3 > Sealant layer

The sealant layer 2 contains polyethylene as in the case of the base material layer 1. By adopting such a constitution, a packaging material or the like having sufficient strength or heat resistance and being recyclable can be produced.

As the resin constituting the sealant layer 2, for example, a vinyl resin such as a low density polyethylene resin (LDPE), a medium density polyethylene resin (MDPE), a linear low density polyethylene resin (LLDPE), an ethylene-vinyl acetate copolymer (EVA), an ethylene- α -olefin copolymer, or an ethylene- (meth) acrylic acid copolymer; a blend resin of polyethylene and polybutylene; or polypropylene resins such as propylene-ethylene random copolymers and propylene-ethylene block copolymers. These thermoplastic resins may be appropriately selected depending on the use or isothermal conditions such as boiling treatment.

The sealant layer 2 may contain the above-described additives within a range that does not impair the characteristics described with respect to the laminate 10C 1.

The thickness of the sealant layer 2 may be appropriately set in consideration of the shape of the package bag to be manufactured, the quality of the contained contents, and the like, and may be, for example, 30 to 150 μm.

The sealant layer 2 is formed by adhering a sealant film to the intermediate layer 8 via an adhesive. The sealant layer 2 may be formed by an extrusion lamination method in which a thermoplastic resin is melted by heating and extruded into a curtain shape, and then bonded to the intermediate layer 8. In this case, the second adhesive layer 3B may be omitted.

< 3.4 > Interlayer

An intermediate layer 8 is present between the substrate layer 1 and the sealant layer 2. The intermediate layer 8 comprises polyethylene. In the laminate 10C1, the probe-lowering temperature of the intermediate layer 8 is 180 ℃. The intermediate layer 8 preferably has a probe-lowering temperature of 220 ℃ or lower. Such an intermediate layer 8 contributes to an improvement in strength, in particular, an improvement in puncture strength, while improving the recycling property of the laminate 10C 1.

The intermediate layer 8 having a probe lowering temperature of 180 ℃ or higher is preferably a stretched film. The stretched film may be a uniaxially stretched film or a biaxially stretched film.

In the present embodiment, an intermediate layer having a probe-lowering temperature of 140 ℃ or higher and less than 180 ℃ may be used. By using an intermediate layer having a probe lowering temperature of 140 ℃ or more and less than 180 ℃, the strength of the laminate, particularly the drop strength, can be improved. As the intermediate layer having a probe-lowering temperature of 140℃or more and less than 180℃an unstretched film is preferable.

As the polyethylene, for example, those described above with respect to the polyethylene contained in the base material layer 1 can be used. Among the above, the polyethylene contained in the intermediate layer 8 is preferably high-density polyethylene or medium-density polyethylene from the viewpoints of strength, heat resistance, and film stretch suitability.

The intermediate layer 8 may contain the above-described additives within a range that does not impair the characteristics described with respect to the laminate 10C 1.

The thickness of the intermediate layer 8 is preferably 9 μm or more and 50 μm or less, more preferably 12 μm or more and 30 μm or less.

When the thickness of the intermediate layer 8 is increased, the strength and heat resistance of the laminate 10C1 can be improved. In addition, when the thickness of the intermediate layer 8 is reduced, the processing suitability of the laminated body 10C1 can be improved.

The intermediate layer 8 may be formed by the T-die method or the inflation method, or may be commercially available.

< 3.5 > Adhesive layer

The first adhesive layer 3A is present between the base material layer 1 and the intermediate layer 8 and adheres them. The second adhesive layer 3B is present between the sealant layer 2 and the intermediate layer 8 and adheres them. These adhesive layers can improve the adhesion between layers.

As the adhesive for forming the first adhesive layer 3A and the second adhesive layer 3B, for example, a known adhesive for dry lamination can be used. The adhesive may be used without any particular limitation as long as it is an adhesive for dry lamination. Specific examples thereof include two-component curable ester adhesives, ether adhesives, and one-component curable or two-component curable urethane adhesives. The adhesion of the base material layer 1 to the intermediate layer 8 and the adhesion of the sealant layer 2 to the intermediate layer 8 can be performed by a solvent-free dry lamination method using a solvent-free adhesive.

As the adhesive for forming the first adhesive layer 3A and the second adhesive layer 3B, a gas barrier adhesive exhibiting gas barrier properties after curing may be used. By using the gas barrier adhesive, the gas barrier property of the laminate 10C1 can be improved. The oxygen permeability of the adhesive layer formed of the gas barrier adhesive is preferably 150cc/m ² day atm or less, more preferably 100cc/m ² day atm or less, still more preferably 80cc/m ² day atm or less, and particularly preferably 50cc/m ² day atm or less. When the adhesive layer having a small oxygen permeability is provided, the gas barrier property of the laminate 10C1 can be improved.

As will be described later, the laminate 10C1 may further include an inorganic compound layer. When the gas barrier adhesive is used, even if a slight crack or the like occurs in the inorganic compound layer, the gas barrier adhesive is coated thereon, so that the gas barrier adhesive penetrates into the void generated in the inorganic compound layer, whereby the decrease in the gas barrier property can be suppressed.

Examples of the gas barrier adhesive include epoxy adhesives and polyester-polyurethane adhesives. Specific examples of the GAS barrier adhesive include "Maxive" manufactured by mitsubishi GAS chemistry company and "Paslim" manufactured by DIC company.

When the first adhesive layer 3A and the second adhesive layer 3B are formed of a gas-barrier adhesive, the thickness thereof is preferably 50 times or more the thickness of the inorganic compound layer. When the first adhesive layer 3A and the second adhesive layer 3B are thickened, the effect of suppressing cracking of the inorganic compound layer is high, and the gas barrier property of the laminate 10C1 is improved. When the first adhesive layer 3A and the second adhesive layer 3B are thickened, cushioning properties for relieving external impact can be further imparted to these adhesive layers, and cracking of the inorganic compound layer due to impact can be prevented. From the viewpoints of flexibility maintenance, processing suitability, and cost of the laminate 10C1, the thickness of the first adhesive layer 3A and the second adhesive layer 3B is preferably 300 times or less the thickness of the inorganic compound layer.

The thickness of the first adhesive layer 3A and the second adhesive layer 3B is, for example, 0.1 to 20 μm, preferably 0.5 to 10 μm, and more preferably 1 to 5 μm.

The adhesive may be applied by, for example, bar coating, dip coating, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, spray coating, or gravure offset printing. The temperature at which the coating film of the adhesive is dried may be, for example, 30 to 200 ℃, preferably 50 to 180 ℃. The temperature at which the coating film is cured may be, for example, room temperature to 70 ℃, preferably 30 to 60 ℃. When the temperature at the time of drying and curing is within the above range, cracking in the inorganic compound layer, the first adhesive layer 3A, and the second adhesive layer 3B can be further suppressed, and excellent gas barrier properties can be exhibited.

From the viewpoint of preventing cracking of the inorganic compound layer 5, the first adhesive layer 3A or the second adhesive layer 3B is preferably in direct contact with the inorganic compound layer, but other layers may be present therebetween.

Effect of < 3.6 >

The probe-lowering temperature of the base material layer 1 of the laminate 10C1 is within the above range. Therefore, the laminate 10C1 is excellent in heat resistance, similar to the laminate 10 A1.

The laminate 10C1 includes the intermediate layer 8 having the probe-lowering temperature within the above range. The intermediate layer 8 can improve the strength of the laminate 10C1, in particular, can improve the puncture strength. Therefore, the laminate 10C1 is excellent in strength, in particular, puncture strength.

Further, the proportion of polyethylene in the laminate 10C1 is 90 mass% or more. Therefore, the laminated body 10C1 is also excellent in recycling property.

Further, a laminate having a high proportion of polyethylene has a lower stiffness than other laminates, and therefore has a high chance of being bent when used as a packaging material. If the chance of bending increases, pinholes are highly likely to occur, but pinholes are less likely to occur in the laminate 10C1 having excellent puncture strength.

< 3.7 > Modification example

The laminate 10C1 may be variously modified.

Fig. 6 is a cross-sectional view schematically showing a first modification of the laminate shown in fig. 5. Fig. 7 is a cross-sectional view schematically showing a second modification of the laminate shown in fig. 5.

The laminate 10C2 shown in fig. 6 and the laminate 10C3 shown in fig. 7 are the same as the laminate 10C1 except that the inorganic compound layer 5 is further included. In the laminate 10C2, the inorganic compound layer 5 is present between the first adhesive layer 3A and the intermediate layer 8. In the laminate 10C3, the inorganic compound layer 5 is present between the second adhesive layer 3B and the intermediate layer 8. That is, in the laminate 10C2, the inorganic compound layer 5 is provided on one surface of the intermediate layer 8, and in the laminate 10C3, the inorganic compound layer 5 is provided on the other surface of the intermediate layer 8. The inorganic compound layer 5 may also be provided on both sides of the intermediate layer 8. The inorganic compound layer 5 may also be present between the substrate layer 1 and the first adhesive layer 3A.

The inorganic compound layer 5 improves the gas barrier property of the laminate, specifically, the oxygen barrier property and the water vapor barrier property.

Examples of the material constituting the inorganic compound layer 5 include inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, tin oxide, zinc oxide, and indium oxide, and aluminum oxide or silicon oxide is particularly preferable from the viewpoint of excellent productivity and excellent oxygen barrier property and water vapor barrier property in a high-temperature or high-humidity heat environment. The inorganic compound layer 5 may contain 1 kind thereof alone or 2 or more kinds thereof in combination.

The thickness of the inorganic compound layer 5 is preferably 1 to 200nm, and when the thickness is increased, the oxygen barrier property and the water vapor barrier property are improved. However, when the thickness is increased, the manufacturing cost increases, and cracks are easily generated due to external forces such as bending and stretching, so that deterioration of barrier properties due to such cracks is easily generated.

The thickness of the deposited film formed of alumina is preferably 5nm to 30 nm. When the film thickness is 5nm or more, sufficient gas barrier properties can be obtained. When the film thickness is 30nm or less, cracking due to deformation caused by internal stress of the thin film can be suppressed, and a decrease in gas barrier property can be suppressed. In addition, when the film thickness exceeds 30nm, the cost tends to increase due to an increase in the amount of material used, a long film formation time, and the like, and therefore, it is not preferable from the economical point of view. From the same viewpoint as described above, the thickness of the vapor deposited film formed of alumina is more preferably 7nm to 15 nm.

The thickness of the deposited film formed of silicon oxide is preferably 10nm to 50 nm. When the film thickness is 10nm or more, sufficient gas barrier properties can be obtained. When the film thickness is 50nm or less, cracking due to deformation caused by internal stress of the thin film can be suppressed, and a decrease in gas barrier property can be suppressed. In addition, when the film thickness exceeds 50nm, the cost tends to increase due to an increase in the amount of material used, a long film formation time, and the like, and therefore, it is not preferable from the economical point of view. From the same viewpoint as described above, the thickness of the vapor deposited film formed of silicon oxide is more preferably 20nm to 40 nm.

The inorganic compound layer 5 can be formed by a known film formation method such as vacuum deposition, sputtering, ion plating, or Chemical Vapor Deposition (CVD). In particular, a roll-to-roll vacuum vapor deposition method is preferable from the viewpoint of productivity.

The layered bodies 10C2 and 10C3 may include the coating layers described in the second embodiment instead of the inorganic compound layer 5. The laminate 10C2 may further include the coating layer between the inorganic compound layer 5 and the first adhesive layer 3A. The laminate 10C3 may further include the coating layer between the inorganic compound layer 5 and the second adhesive layer 3B. The coating layer, or the combination of the coating layer and the inorganic compound layer 5 may also function as a gas barrier layer.

The laminated bodies 10C1, 10C2, and 10C3 may further include 1 or more of a printed layer, a protective layer, a light shielding layer, and other functional layers, as necessary.

The printed layer may be provided at a position visible from the outside in the packaged state for the purpose of improving display of content-related information, identification of content, or design of the package. The printing method and the printing ink are not particularly limited, and may be appropriately selected from known printing methods and printing inks in consideration of suitability for printing on films, designability, adhesiveness, etc. of color tones, etc., safety as food containers, etc. As the ink, a biomass ink containing a biomass-derived material can also be preferably used. In addition, light-shielding inks can also be used preferably. Examples of the light-shielding ink include white ink, black ink, silver ink, and dark brown ink.

As the printing method, for example, an intaglio printing method, an offset printing method, an intaglio offset printing method, a flexographic printing method, and an inkjet printing method can be exemplified. Among them, the gravure printing method is preferable from the viewpoint of productivity and high fineness of the pattern. In order to improve the adhesion of the printed layer, various pretreatment such as corona treatment, plasma treatment, and flame treatment, or a coating layer such as an easy-to-adhere layer may be provided on the surface of the layer forming the printed layer.

The print layer is provided on any one of, for example, the surface of the base material layer 1, the back surface of the base material layer 1, the surface (front surface) of the intermediate layer 8 facing the base material layer 1, and the surface (back surface) of the intermediate layer 8 facing the sealant layer 2.

In addition, as a method for imparting light shielding properties to the laminate, a metal deposition layer may be provided on the substrate, the intermediate layer, or the sealant layer. The metal deposition layer may be aluminum deposition.

< 4 > Fourth embodiment

< 4.1 > Laminate

The laminate 10D1 shown in fig. 8 is similar to the laminate 10C3 except that it further includes a printed layer 4 interposed between the base layer 1 and the first adhesive layer 3A, a protective layer 6 provided on the surface of the base layer 1, and a coating layer 7 interposed between the inorganic compound layer 5 and the second adhesive layer 3B. As the print layer 4, those described in the first and third embodiments can be used. As the protective layer 6 and the coating layer 7, those described in the second embodiment can be used.

Effect of < 4.2 >

The probe-reduced temperature of the base material layer 1 of the laminate 10D1 falls within the above range. Further, the laminate 10D1 includes the protective layer 6. Therefore, the laminate 10D1 can achieve more excellent heat resistance, in particular, more excellent heat seal suitability. Therefore, when the above-described structure is employed for the laminate 10D1, the temperature range of the heat seal for bag making becomes wider, and the productivity is more unlikely to be lowered.

The laminate 10D1 includes the intermediate layer 8 having the probe descent temperature within the above range. The intermediate layer 8 can improve the strength of the laminate 10D1, in particular, can improve the puncture strength. Thus, the laminate 10D1 is excellent in strength, in particular, puncture strength.

Further, when the haze of the base material layer 1 is small, the transparency is excellent. Therefore, at this time, the image such as the pattern or the character displayed on the print layer 4 can be seen with good visibility.

Further, the proportion of polyethylene in the laminate 10D1 is 90 mass% or more. Thus, the laminated body 10D1 is also excellent in recycling property.

< 4.3 > Modification example

The laminate 10D1 may be variously modified.

For example, the inorganic compound layer 5 may be provided on the surface of the intermediate layer 8 instead of being provided on the back surface of the intermediate layer 8. At this time, the coating layer 7 is provided so as to cover the inorganic compound layer 5.

One of the inorganic compound layer 5 and the coating layer 7 may be omitted. When high barrier properties are not required, both the inorganic compound layer 5 and the coating layer 7 may be omitted.

The printed layer 4 may be provided on the surface of the substrate layer 1, on the surface of the intermediate layer 8, or on the back surface of the intermediate layer 8. In any case, the image such as a pattern or a character displayed on the printed layer 4 can be seen with good visibility. The print layer 4 may be omitted.

< 5 > Fifth embodiment

< 5.1 > Laminate

Laminate 10E1 shown in fig. 9 is similar to laminate 10C1, except that the probe-lowering temperature of intermediate layer 8 is 180 ℃ or lower. The probe-down temperature of the intermediate layer 8 is preferably less than 180 ℃. The probe-lowering temperature of the intermediate layer 8 is preferably 140℃or higher. In the laminate 10E1, the intermediate layer 8 is preferably an unstretched film. Such an intermediate layer 8 can improve the strength of the laminate 10E1, in particular, can improve the drop strength.

In the present embodiment, an intermediate layer having a probe-lowering temperature of 180 ℃. When the intermediate layer having the probe-lowering temperature in the above range is used, the strength of the laminate, particularly the puncture strength, can be improved. The intermediate layer having a probe lowering temperature of 180℃or higher is preferably a stretched film.

Effect of < 5.2 >

The probe-reduced temperature of the base material layer 1 of the laminate 10E1 falls within the above range. Therefore, the laminate 10E1 is excellent in heat resistance, similar to the laminate 10 A1.

The laminate 10E1 includes the intermediate layer 8 having the probe descent temperature within the above range. The intermediate layer 8 can improve the strength of the laminate 10E1, in particular, can improve the drop strength. That is, in the laminate 10E1, the intermediate layer 8 located inside the base material layer 1 is softer than the base material layer 1 when used in a package. This structure is suitable for absorbing an impact generated when a packaged article using the laminate 10E1 as a packaging material is dropped. Therefore, the packaged article using the laminate 10E1 as a packaging material is less likely to be broken (bag broken) by dropping. Therefore, the laminate 10E1 is excellent in strength, particularly in drop strength.

Further, the proportion of polyethylene in the laminate 10E1 is 90 mass% or more. Therefore, the laminate 10E1 is also excellent in recycling property.

< 5.3 > Modification example

The laminate 10E1 may be variously modified.

Fig. 10 is a cross-sectional view schematically showing a first modification of the laminate shown in fig. 9. Fig. 11 is a cross-sectional view schematically showing a second modification of the laminate shown in fig. 9.

The laminate 10E2 shown in fig. 10 and the laminate 10E3 shown in fig. 11 are the same as the laminate 10E1 except that they further include the inorganic compound layer 5 described in the third embodiment. In the laminate 10E2, the inorganic compound layer 5 is present between the first adhesive layer 3A and the intermediate layer 8. In the laminate 10E3, the inorganic compound layer 5 is present between the second adhesive layer 3B and the intermediate layer 8. That is, in the laminate 10E2, the inorganic compound layer 5 is provided on one surface of the intermediate layer 8, and in the laminate 10E3, the inorganic compound layer 5 is provided on the other surface of the intermediate layer 8. The inorganic compound layer 5 may also be provided on both sides of the intermediate layer 8. The inorganic compound layer 5 may be present between the base material layer 1 and the first adhesive layer 3A.

The layered bodies 10E2 and 10E3 may include the coating layers described in the second embodiment instead of the inorganic compound layer 5. The laminate 10E2 may further include the coating layer between the inorganic compound layer 5 and the first adhesive layer 3A. The laminate 10E3 may further include the coating layer between the inorganic compound layer 5 and the second adhesive layer 3B. The coating layer, or the combination of the coating layer and the inorganic compound layer 5 may also function as a gas barrier layer.

The laminated bodies 10E1, 10E2, and 10E3 may further include 1 or more of a printed layer, a protective layer, a light shielding layer, and other functional layers, as necessary. The print layer is, for example, as described in the third embodiment.

< 6 > Sixth embodiment

< 6.1 > Laminate

The laminate 10F1 shown in fig. 12 is similar to the laminate 10E3 except that it further includes a printed layer 4 interposed between the base layer 1 and the first adhesive layer 3A, a protective layer 6 provided on the surface of the base layer 1, and a coating layer 7 interposed between the inorganic compound layer 5 and the second adhesive layer 3B. As the print layer 4, those described in the first and third embodiments can be used. As the protective layer 6 and the coating layer 7, those described in the second embodiment can be used.

Effect of < 6.2 ]

The probe-reduced temperature of the base material layer 1 of the laminate 10F1 falls within the above range. Further, the laminate 10F1 includes the protective layer 6. Thus, the laminate 10F1 can achieve more excellent heat resistance, and in particular, can achieve more excellent heat seal suitability. Therefore, when the above-described structure is adopted for the laminate 10F1, the temperature range of the heat seal performed for bag making becomes wider, and the productivity is more unlikely to be lowered.

The laminate 10F1 includes the intermediate layer 8 having the probe descent temperature within the above range. The intermediate layer 8 can improve the strength of the laminate 10F1, in particular, can improve the drop strength. Thus, the laminate 10F1 is excellent in strength, in particular, in drop strength.

Further, the proportion of polyethylene in the laminate 10F1 is 90 mass% or more. Thus, the laminate 10F1 is also excellent in recycling property.

< 6.3 > Modification example

The laminate 10F1 may be variously modified.

For example, the inorganic compound layer 5 may be provided on the surface of the intermediate layer 8 instead of being provided on the back surface of the intermediate layer 8. At this time, the coating layer 7 is provided in such a manner as to cover the inorganic compound layer 5.

< 7 > Seventh embodiment

The packaged article 100A shown in fig. 13 includes a package 110A and contents stored therein.

The package 110A is a three-side sealed pouch. The package 110A includes a pair of body films. Each of the main body films is a laminate described in the first to sixth embodiments, or is cut out therefrom. The body films are overlapped with the sealant layers facing each other, and the peripheral portions are heat-sealed to each other. The package 110A has an easy-to-tear opening as an easy-to-open structure in its heat sealed portion.

The contents may be any of liquids, solids, and mixtures thereof. The content is, for example, a food or a pharmaceutical agent.

< 8 > Eighth embodiment

The packaged article 100B shown in fig. 14 includes a package 110B and contents stored therein. The contents are, for example, the same as described with respect to packaged article 100A.

The package 110B is a stand-alone pouch. The package 110B includes a pair of main body films and a base film. Each film is a laminate described in the first to sixth embodiments, or is cut out therefrom.

The pair of body films are overlapped with the sealant layers facing each other, and peripheral portions are heat-sealed to each other except for one end and the vicinity thereof. The base film is folded in half so as to become a mountain fold when viewed from the sealant layer side, and the mountain fold portion is sandwiched between the pair of main films so as to face the other end of the main films at the position of the one end. The portions of the base film other than the central portion thereof are heat-sealed to a pair of main body films. In addition, the base film adheres the outer surfaces to each other at positions on both sides of the bottom of the package 110B.

In the package 110B, an easy-to-tear opening is provided as an easy-to-open structure in a portion between the heat-sealed main body films. The easy-opening structure may be provided so that the corner above the packaged article 100B can be used as the mouth when opening the packaged article. Or the packaged article 100B may further include the mouth member and the lid described in the ninth embodiment.

< 9 > Ninth embodiment

The packaged article 100C shown in fig. 15 includes a package 110C and contents stored therein. The contents are, for example, the same as described with respect to packaged article 100A.

The package 110C is an organ bag. The package 110C includes a container body 110C1, a mouth member 110C2, and a lid 110C3.

The container body 110C1 includes a pair of body films and a pair of side films.

The pair of body films are overlapped with their sealant layers facing each other so as to sandwich a part of the mouth member 110C2 at one end. The peripheral portions of these main body films are heat-sealed to the mouth member 110C2 at the one end described above while being heat-sealed to each other in the vicinity thereof. In addition, the peripheral portions of these main body films are heat-sealed to each other at one end of the opposite sides thereof except for the regions of both sides.

Each side film is folded in half so as to become a mountain fold when viewed from the sealant layer side. The side films are sandwiched between a pair of main films at both sides of the main films so that the mountain portions face each other. A portion of the peripheral portion of each side film is heat sealed to one of the body films, and the remaining portion of the peripheral portion is heat sealed to the other of the body films. In addition, each side film bonds the outer surfaces to each other at each of the upper and lower portions of the package 110C.

In addition, the container body 110C1 may further include a base film.

The mouth member 110C2 includes the portions where they are heat-sealed while being sandwiched by the main body films, as described above. The mouth member 110C2 further includes a mouth portion protruding outward from the container body 110C 1. The mouth has a substantially cylindrical shape, and an external thread is provided on the outside of the side wall. The cover 110C3 has a bottomed cylindrical shape. The cap 110C3 has an internal thread on the inner surface of the side wall, and is screwed into the mouth of the mouth member 110C 2.

Examples

The results of the experiments conducted in accordance with the present invention are described below.

(1) Test A

(1.1) Production of laminate

(1.1.1) Example 1A

The laminate 10A2 shown in fig. 2 was produced by the following method.

First, a polyethylene film having a thickness of 25 μm and a probe lowering temperature of 211℃was prepared as a base layer. The method for measuring the probe-drop temperature used in this example and the examples described below and the comparative examples will be described later.

Then, corona treatment is performed on one surface of the base material layer. Next, a silicon oxide (SiO _x) vapor-deposited film was formed as an inorganic compound layer so as to have a thickness of 40nm using a vacuum vapor deposition apparatus of electron beam heating system on the corona-treated surface of the base material layer. Thereafter, a pattern is printed on the inorganic compound layer using gravure ink to form a printed layer.

Next, a dry lamination adhesive (urethane adhesive) is applied to the surface of the base material layer on which the print layer is formed. Then, a linear low density polyethylene resin (LLDPE) film (thickness: 60 μm) as a sealant layer was adhered to the base material layer via the adhesive layer.

A laminate was produced as described above.

(1.1.2) Example 2A

A laminate 10A1 shown in fig. 1 was produced in the same manner as in example 1A, except that the inorganic compound layer was not provided.

(1.1.3) Example 3A

A laminate 10A2 shown in fig. 2 was produced in the same manner as in example 1A, except that a polyamine-based gas barrier adhesive was used as the adhesive instead of using a dry lamination adhesive (urethane-based adhesive).

(1.1.4) Example 4A

A laminate 10A2 shown in fig. 2 was produced in the same manner as in example 1A, except that a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211 ℃ was used as the base layer, and a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 205 ℃ was used.

(1.1.5) Example 5A

A laminate 10A2 shown in fig. 2 was produced in the same manner as in example 1A, except that a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211 ℃ was used as the base layer, and a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 203 ℃ was used.

(1.1.6) Example 6A

A laminate 10A2 shown in fig. 2 was produced in the same manner as in example 1A, except that a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211 ℃ was used as the base layer, and a polyethylene film having a thickness of 20 μm and a probe-lowering temperature of 211 ℃ was used.

(1.1.7) Example 7A

A laminate 10A2 shown in fig. 2 was produced in the same manner as in example 1A, except that a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211 ℃ was used as the base layer, and a polyethylene film having a thickness of 30 μm and a probe-lowering temperature of 211 ℃ was used.

(1.1.8) Example 8A

A laminate 10A2 shown in fig. 2 was produced in the same manner as in example 1A, except that a linear low density polyethylene resin (LLDPE) film having a thickness of 40 μm was used as the sealant layer instead of using a linear low density polyethylene resin (LLDPE) film having a thickness of 60 μm.

(1.1.9) Example 9A

A laminate 10A2 shown in fig. 2 was produced in the same manner as in example 1A, except that a linear low density polyethylene resin (LLDPE) film having a thickness of 120 μm was used as the sealant layer instead of using a linear low density polyethylene resin (LLDPE) film having a thickness of 60 μm.

(1.1.10) Example 10A

A laminate 10A1 shown in fig. 1 was produced in the same manner as in example 2A, except that a polyamine-based gas barrier adhesive was used as an adhesive instead of using a dry lamination adhesive (urethane-based adhesive).

(1.1.11) Example 11A

A laminate 10A1 shown in fig. 1 was produced in the same manner as in example 2A, except that a urethane gas barrier adhesive was used as an adhesive instead of using a dry lamination adhesive (urethane adhesive).

(1.1.12) Comparative example 1A

A laminate was produced in the same manner as in example 1A, except that a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211 ℃ was used as the base layer, and a polyethylene film having a thickness of 40 μm and a probe-lowering temperature of 156 ℃ was used.

(1.1.13) Comparative example 2A

A laminate was produced in the same manner as in example 1A, except that a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211 ℃ was used as the base layer, and a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 160 ℃ was used instead.

(1.1.14) Comparative example 3A

A laminate was produced in the same manner as in example 1A, except that a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211 ℃ was used as the base layer, and a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 164 ℃ was used instead.

(1.2) Measurement and evaluation method

The substrate layer used for the production of the laminate was subjected to in-plane measurement by the wide-angle X-ray diffraction method. Further, it was examined whether or not the diffraction pattern obtained by the measurement had a sharp diffraction peak corresponding to the (110) plane.

The laminate was evaluated for sealability, heat resistance, print visibility, and gas barrier property. The method for measuring the probe drop temperature, the method for evaluating sealability, heat resistance, printing visibility, and gas barrier property are described below.

(1.2.1) Method for measuring the temperature at which the probe decreases

The probe descent temperature was measured by the following method.

As an atomic force microscope, MPF-3D-SA (trade name) manufactured by Oxford Instruments Co., ltd was used. Ztherm (trade name) manufactured by Oxford Instruments corporation was used as a nanothermal microscope incorporated therein. As the cantilever (probe), AN2-200 (trade name) manufactured by Anaxis Instruments Co., ltd was used.

In measurement, first, the shape of a sample was measured in an AC mode for a10 μm square field of view. Then, the cantilever (probe) is separated from the sample by 5 to 10 μm in the Z direction. In this state, the Detrend correction function of the device is activated in the contact mode under the conditions of a maximum applied voltage of 6V and a heating rate of 0.5V/s, and the change in the bending amount (Deflection) of the cantilever (probe) due to the voltage application is corrected. Then, the cantilever was brought into contact with the sample in such a manner that the variation in Deflection before and after the contact between the cantilever and the sample became 0.2V, the Deflection was kept at a constant value, and the sample was heated by applying a voltage to the cantilever under the conditions of a maximum applied voltage of 6V and a heating rate of 0.5V/s. The Z displacement at this time was recorded, and the measurement was stopped at a point in time when the Z displacement was changed from ascending to descending and from the change point to descending by 50 nm. When the Z displacement reaches the maximum applied voltage without decreasing by 50nm from the change point, the maximum applied voltage at Detrend is increased by 0.5V at the time of the compensation and measurement, and the same operation as described above is performed again. The applied voltage at which the recorded Z displacement reaches the maximum is converted into temperature with reference to a standard curve described later. This measurement was performed at 10 points in a10 μm square field of view, and the average value of the obtained temperatures was used as the probe-lowering temperature.

In order to obtain a standard curve for converting an applied voltage into temperature, polycaprolactone (melting point: 60 ℃ C.), low-density polyethylene (melting point: 112 ℃ C.), polypropylene (melting point: 166 ℃ C.), and polyethylene terephthalate (melting point: 255 ℃ C.) were prepared as constituent samples. The melting point of the calibration sample is a melting peak temperature measured by a Differential Scanning Calorimeter (DSC) at a temperature rise rate of 5 ℃/min.

The same measurement as described above was performed on each of these calibration samples. In addition, the maximum applied voltage at Detrend ℃and at the time of measurement was 3.5V for polycaprolactone, 5.5V for low density polyethylene, 6.5V for polypropylene and 7.8V for polyethylene terephthalate.

Further, in the measurement of the calibration sample, the relationship between the applied voltage at which the Z displacement becomes maximum and the melting point of the constituent sample is approximated by using the 3-order function for the least square method, and a standard curve is prepared.

(1.2.2) Method for evaluating sealability

The sample obtained by cutting the laminate into 10cm square was folded in half so that the sealant layer was inside, and heat-sealed using a heat sealer. Specifically, the lower surface sealing temperature was set at 100℃and the upper surface sealing temperature was set at 120℃at the same time, and a pressure of 0.1MPa was applied for 1 second. Further, the upper surface of the folded sample was observed for the area contacting the heat sealing bar while confirming the presence or absence of melting of the sealing surface. When the sealing surface was not melted and the upper surface of the sample was not melted, the upper surface sealing temperature was increased every 10 ℃ while the lower surface sealing temperature was fixed at 100 ℃ until at least one of the sealing surface and the upper surface of the sample was melted, and the same pressurization and observation as described above were performed. Further, the sealability was evaluated by the following criteria.

A: the upper surface of the sample was not melted and had no problem in appearance.

B: the upper surface of the sample was melted and had a problem in appearance.

(1.2.3) Evaluation method of printing visibility

The pattern displayed on the printed layer was visually observed from the substrate layer side, and the visibility was evaluated using the following criteria.

A: the pattern displayed on the printed layer was clearly confirmed.

B: the printed layer showed a blurred and unclear pattern.

(1.2.4) Method for evaluating gas Barrier Properties

After the laminate was boiled, the oxygen permeation rate (Oxygen Transmission Rate, OTR) at 30 ℃ and a relative humidity of 70% was measured. An oxygen permeability measuring apparatus (OXTRAN-2/20, manufactured by MOCON Co., ltd.) was used for the measurement. Further, the oxygen permeation rate was referred to the following criteria, and the gas barrier property was evaluated.

A: OTR is less than 10cc/m ². Day. Atm.

B: OTR is 10cc/m ². Day. Atm or more.

(1.2.5) Method for evaluating Heat resistance

The sample obtained by cutting the laminate into 10cm square was folded in half so that the sealant layer was inside. Then, the lower surface sealing temperature of the heat sealer was set to 30℃and the upper surface sealing temperature was set to 170℃and a pressure of 0.2MPa was applied to the folded sample for 1 second. Further, the presence or absence of melting of the sealing surface was checked, and whether or not the region of the upper surface of the folded sample, which contacted the heat sealing bar, was adhered to the heat sealing bar was observed, and the heat resistance was evaluated by the following criteria.

A: the upper surface of the test specimen was not attached to the heat sealing bar.

B: the upper surface of the test specimen was attached to a heat seal bar.

(1.3) Results

The results of the measurement and evaluation are shown in tables 1A and 1B below.

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As shown in tables 1A and 1B, the laminate having the probe lowering temperature of 180 ℃ or higher in the base material layer was excellent in sealability, heat resistance and printing visibility. The laminate having the substrate layer reduced in temperature below 180℃by the probe is insufficient in sealability, heat resistance and visibility.

(2) Test B

(2.1) Production of laminate

(2.1.1) Example 1B

The laminate 10B2 shown in fig. 4 was manufactured by the following method.

First, a polyethylene film having a thickness of 25 μm and a probe lowering temperature of 211℃was prepared as a base layer. As will be described later, the probe-down temperature in this example and the examples and comparative examples described below was measured by the method described in (1.2.1).

Then, corona treatment is performed on one surface of the base material layer. Next, a protective layer having a thickness of 0.5nm was formed by applying a polyamide-imide resin to the corona-treated surface of the base layer. The concentration of the nonvolatile component in the coating liquid used for forming the protective layer was 5% by mass.

Then, corona treatment is performed on the other surface of the base material layer. Next, a silicon oxide (SiO _x) vapor-deposited film was formed as an inorganic compound layer so as to have a thickness of 40nm using a vacuum vapor deposition apparatus of electron beam heating system on the corona-treated surface of the base material layer. Then, a coating liquid for forming a coating layer was applied to the inorganic compound layer to form a coating layer having a thickness of 0.3 μm and formed from the organic-inorganic mixture. Thereafter, a pattern is printed on the inorganic compound layer using gravure ink to form a printed layer.

Next, a dry lamination adhesive (urethane adhesive) is applied to the surface of the base material layer on which the print layer is formed. Next, a linear low density polyethylene resin (LLDPE) film (thickness: 60 μm) as a sealant layer was adhered to the base layer via the adhesive layer.

A laminate was produced as described above.

(2.1.2) Example 2B

A laminate 10B2 shown in fig. 4 was produced in the same manner as in example 1B, except that the thickness of the protective layer was 1 μm.

(2.1.3) Example 3B

A laminate was produced in the same manner as in example 1B, except that the protective layer was not provided.

(2.1.4) Example 4B

A laminate 10B2 shown in fig. 4 was produced in the same manner as in example 1B, except that a protective layer having a thickness of 0.5 μm was formed by applying a polyamideimide resin instead of forming a protective layer having a thickness of 0.5 μm formed by an organic-inorganic mixture. The protective layer formed of the organic-inorganic mixture is formed by applying the coating liquid for forming the coating layer.

(2.1.5) Example 5B

A laminate 10B2 shown in fig. 4 was produced in the same manner as in example 1B, except that a protective layer having a thickness of 0.5 μm was formed by coating a polyamideimide resin instead of forming a protective layer having a thickness of 0.5 μm formed by urethane resin.

(2.1.6) Example 6B

A laminate 10B2 shown in fig. 4 was produced in the same manner as in example 1B, except that a protective layer having a thickness of 0.5 μm was formed instead of coating the polyamideimide resin, and a protective layer having a thickness of 1 μm was formed of the urethane resin.

(2.1.7) Example 7B

A laminate 10B2 shown in fig. 4 was produced in the same manner as in example 1B, except that a protective layer having a thickness of 0.5 μm was formed instead of coating the polyamideimide resin, and a protective layer having a thickness of 1 μm was formed from an ethylene-vinyl alcohol copolymer (EVOH).

(2.1.8) Example 8B

A laminate 10B2 shown in fig. 4 was produced in the same manner as in example 1B, except that a protective layer having a thickness of 0.5 μm was formed instead of coating the polyamideimide resin, and a protective layer having a thickness of 1 μm was formed of the acrylic resin.

(2.1.9) Comparative example 1B

A laminate was produced in the same manner as in example 1B, except that the protective layer was not provided, instead of using a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211 c, a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 152 c was used.

(2.2) Measurement and evaluation method

In addition, sealability, heat resistance and printing visibility were evaluated for the laminate. The method for measuring the probe drop temperature, the method for evaluating sealability, heat resistance and printing visibility are described below.

(2.2.1) Method for measuring the temperature at which the probe falls

The probe-reduced temperature was measured by the method described in (1.2.1).

(2.2.2) Method for evaluating sealability

The sample obtained by cutting the laminate into 10cm square was folded in half so that the sealant layer was inside, and heat-sealed using a heat sealer. Specifically, the lower surface sealing temperature was set at 100℃and the upper surface sealing temperature was set at 120℃at the same time, and a pressure of 0.1MPa was applied for 1 second. Further, the upper surface of the folded sample was observed for the area contacting the heat sealing bar while confirming the presence or absence of melting of the sealing surface. When the upper surface of the sample was not melted or had a poor appearance, the upper surface sealing temperature was increased every 10 ℃ in a state where the lower surface sealing temperature was fixed at 100 ℃ until the upper surface of the sample was melted or had a poor appearance, and the same pressurization and observation as described above were performed. Further, the sealability was evaluated by the following criteria.

A: when the sealing surface is melted, the upper surface of the sample is not melted or has poor appearance.

B: when or before the sealing surface melts, the upper surface of the sample melts or has a poor appearance.

(2.2.3) Method for evaluating printing visibility

The printing visibility was evaluated by the method described in (1.2.3).

(2.2.4) Method for evaluating Heat resistance

The sample obtained by cutting the laminate into 10cm square was folded in half so that the sealant layer was inside. Then, the lower surface sealing temperature of the heat sealer was set to 30℃and the upper surface sealing temperature was set to 170℃to apply a pressure of 0.2MPa to the folded sample for 1 second. Further, the presence or absence of melting of the sealing surface was checked, and whether or not the region of the upper surface of the folded sample contacting the heat sealing bar was adhered to the heat sealing bar was observed, and the heat resistance was evaluated by the following criteria.

B: the upper surface of the test specimen was attached to a heat seal bar.

In addition, heat resistance of the laminate having the protective layer was further evaluated by the same method as described above except that the upper surface sealing temperature was set to 190 ℃.

(2.3) Results

The results of the measurement and evaluation are shown in table 2 below.

As shown in table 2, the laminate having the probe lowering temperature of 180 ℃ or higher was excellent in both heat resistance and printing visibility. Furthermore, the probe lowering temperature of the base material layer was 180 ℃ or higher, and the sealing properties of the laminate having the protective layer were also excellent. The laminate having the substrate layer with a probe-down temperature of less than 180 ℃ and no protective layer is insufficient in sealability, heat resistance and visibility.

(3) Test C

(3.1) Production of laminate

(3.1.1) Example 1C

The laminate 10C2 shown in fig. 6 was produced by the following method. In this example, a print layer is provided between the base material layer 1 and the first adhesive layer 3A.

First, a polyethylene film having a thickness of 25 μm and subjected to corona treatment on one surface was prepared as a base layer. The polyethylene film had a density of 0.950g/cm ³ and a probe-drop temperature of 211 ℃. As will be described later, the probe-down temperature in this example and the examples and comparative examples described below was measured by the method described in (1.2.1). The corona-treated surface of the base material layer is printed with a gravure ink pattern to form a printed layer.

Further, a polyethylene film having a thickness of 25 μm and subjected to corona treatment on one surface was prepared as an intermediate layer. The polyethylene film had a density of 0.950g/cm ³ and a probe-drop temperature of 211 ℃. A silicon oxide (SiO _x) vapor-deposited film was formed on the corona-treated surface of the intermediate layer using a vacuum vapor deposition apparatus of electron beam heating system as an inorganic compound layer so as to have a thickness of 10 nm.

Next, a dry lamination adhesive (urethane adhesive) was applied to the back surface of the substrate layer on which the print layer was formed and the back surface of the intermediate layer on which the inorganic compound layer was formed, and the coating film was dried to form first and second adhesive layers each having a thickness of 3 μm. Further, the base material layer and the intermediate layer were bonded with the first adhesive layer interposed therebetween and the printed layer and the inorganic compound layer facing each other, and the intermediate layer was bonded to a linear low density polyethylene resin (LLDPE) film (thickness: 60 μm) as a sealant layer via the second adhesive layer.

A laminate was produced as described above.

(3.1.2) Example 2C

A laminate 10C1 shown in fig. 5 was produced in the same manner as in example 1C, except that the inorganic compound layer was not provided. In this example, a print layer was also provided between the base material layer 1 and the first adhesive layer 3A, as in example 1C.

(3.1.3) Example 3C

A laminate 10C2 shown in fig. 6 was produced in the same manner as in example 1C, except that a polyamine-based gas barrier adhesive was used as the adhesive instead of using a dry lamination adhesive (urethane-based adhesive). In this example, a print layer was also provided between the base material layer 1 and the first adhesive layer 3A, as in example 1C.

(3.1.4) Example 4C

A laminate 10C2 shown in fig. 6 was produced in the same manner as in example 1C, except that the following polyethylene film was used as the base material layer instead of using the polyethylene film having a probe lowering temperature of 211 ℃. That is, in this example, a polyethylene film having a thickness of 25 μm, a density of 0.950g/cm ³, a probe-descent temperature of 205℃and corona-treated on one surface was used as the base layer. In this example, a print layer was also provided between the base material layer 1 and the first adhesive layer 3A, as in example 1C.

(3.1.5) Example 5C

The laminate 10C2 shown in fig. 6 was produced in the same manner as in example 1C, except for the following matters. That is, in this example, instead of using the polyethylene film having a probe lowering temperature of 211℃as the base material layer, a polyethylene film having a thickness of 25 μm, a density of 0.950g/cm ³, a probe lowering temperature of 203℃and corona-treated on one surface was used. In this example, instead of using the polyethylene film having a probe lowering temperature of 211℃as the intermediate layer, a polyethylene film having a thickness of 25 μm, a density of 0.950g/cm ³, a probe lowering temperature of 205℃and corona-treated on one surface was used. In this example, a print layer was also provided between the base material layer 1 and the first adhesive layer 3A, as in example 1C.

(3.1.6) Example 6C

The laminate 10E2 shown in fig. 10 was produced in the same manner as in example 1C, except for the following matters. That is, in this example, instead of using the polyethylene film having a probe lowering temperature of 211℃as the intermediate layer, a polyethylene film having a thickness of 40 μm, a density of 0.949g/cm ³, a probe lowering temperature of 156℃and corona-treated on one surface was used. In this example, a print layer was also provided between the base material layer 1 and the first adhesive layer 3A, as in example 1C.

(3.1.7) Comparative example 1C

A laminate was produced in the same manner as in example 1C, except that a polyethylene film having a thickness of 40 μm, a density of 0.949g/cm ³, a probe-lowering temperature of 156 ℃ and a corona treatment on one surface was used as the base layer instead of using the above polyethylene film having a probe-lowering temperature of 211 ℃.

(3.1.8) Comparative example 2C

A laminate was produced in the same manner as in example 1C, except for the following matters. That is, in this example, instead of using the polyethylene film having a probe lowering temperature of 211℃as the base material layer, a polyethylene film having a thickness of 40 μm, a density of 0.949g/cm ³, a probe lowering temperature of 156℃and corona-treated on one surface was used. In this example, instead of using the polyethylene film having a probe lowering temperature of 211℃as the intermediate layer, a polyethylene film having a thickness of 40 μm, a density of 0.949g/cm ³, a probe lowering temperature of 156℃and corona-treated on one surface was used.

(3.2) Measurement and evaluation method

The substrate layer and the intermediate layer used in the production of the laminate were subjected to in-plane measurement by the wide-angle X-ray diffraction method. Further, it was examined whether or not the diffraction pattern obtained by the measurement had a sharp diffraction peak corresponding to the (110) plane.

The laminate was evaluated for sealability, heat resistance, print visibility, and gas barrier property. The puncture strength of the laminate was measured. The method for measuring the probe lowering temperature and puncture strength, the method for evaluating sealability, heat resistance, printing visibility, and gas barrier property are described below.

(3.2.1) Method for measuring the temperature at which the probe decreases

The probe-down temperature was measured by the method described in (1.2.1).

(3.2.2) Method for evaluating sealability

The sample obtained by cutting the laminate into 10cm square was folded in half so that the sealant layer was inside, and heat-sealed using a heat sealer. Specifically, a temperature of 140℃and a pressure of 0.1MPa were applied to the folded sample for 1 second. Further, the area of the sample surface contacting the heat sealing bar was observed, and the sealability was evaluated using the following criteria.

A: the surface of the sample was not melted, and there was no problem in appearance.

B: the surface of the sample was melted, and there was a problem in appearance.

(3.2.3) Evaluation method of printing visibility

The printing visibility was evaluated by the method described in (1.2.3).

(3.2.4) Method for evaluating gas Barrier Properties

The gas barrier properties were evaluated by the method described in (1.2.4).

(3.2.5) Method for measuring puncture strength

The laminate was pressed from the base layer side at a speed of 50 mm/min by a needle having a radius of 0.5mm and a hemispherical tip, and the maximum force until penetration of the needle was measured. This measurement was performed several times, and the arithmetic average of the maximum force was obtained as the puncture strength.

(3.2.6) Method for evaluating Heat resistance

The heat resistance was evaluated by the method described in (1.2.5).

(3.3) Results

The results of the measurement and evaluation are shown in table 3 below.

As shown in table 3, the laminate having the probe lowering temperature of 180 ℃ or higher in the base layer was excellent in sealability, heat resistance and printing visibility. Further, the laminate having both the base material layer and the intermediate layer at a probe-reduced temperature of 180 ℃ or higher exhibits high puncture strength. The laminate having the substrate layer reduced in temperature below 180℃by the probe is insufficient in sealability, heat resistance and visibility. In addition, the laminate having both the base material layer and the intermediate layer with a probe-down temperature of less than 180 ℃ exhibited low puncture strength.

(4) Test D

(4.1) Production of laminate

(4.1.1) Example 1D

The laminate 10D1 shown in fig. 8 was produced by the following method.

First, as a base material layer, a polyethylene film having a thickness of 25 μm and a probe lowering temperature of 211℃was prepared. As will be described later, in this example and the examples and comparative examples described below, the probe-down temperature was measured by the method described in (1.2.1).

Then, corona treatment is performed on one surface of the base material layer. Next, a protective layer having a thickness of 0.5 μm was formed by applying a polyamide-imide resin to the corona-treated surface of the base layer. The concentration of the nonvolatile component in the coating liquid used for forming the protective layer was 5% by mass.

Then, corona treatment is performed on the other surface of the base material layer. Next, a pattern was printed on the inorganic compound layer using gravure ink on the corona-treated surface of the base material layer, thereby forming a printed layer.

Further, as an intermediate layer, a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211℃was prepared. Then, corona treatment is applied to one surface of the intermediate layer. A silicon oxide (SiO _x) vapor-deposited film was formed as an inorganic compound layer to a thickness of 40nm using a vacuum vapor deposition apparatus of electron beam heating type on the corona-treated surface of the intermediate layer. Then, a coating liquid for forming a coating layer was applied to the inorganic compound layer to form a coating layer having a thickness of 0.3 μm and formed of an organic-inorganic mixture.

Next, a dry laminating adhesive (urethane adhesive) is applied to the surface of the substrate layer on which the print layer is formed and the surface of the coating layer, and the coating film is dried to form first and second adhesive layers. The base layer and the intermediate layer were further bonded with the first adhesive layer interposed therebetween and the print layer and the intermediate layer facing each other, and the intermediate layer and the sealant layer were bonded with the second adhesive layer interposed therebetween so that the coating layer and a linear low density polyethylene resin (LLDPE) film (thickness: 60 μm) serving as the sealant layer faced each other.

A laminate was produced as described above.

(4.1.2) Example 2D

A laminate 10D1 shown in fig. 8 was produced in the same manner as in example 1D, except that the thickness of the protective layer was 1 μm.

(4.1.3) Example 3D

A laminate 10D1 shown in fig. 8 was produced in the same manner as in example 1D, except that the thickness of the protective layer was 3 μm.

(4.1.4) Example 4D

A laminate was produced in the same manner as in example 1D, except that no protective layer was provided, and instead of using a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211 ℃, a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 160 ℃ was used as the intermediate layer.

(4.1.5) Comparative example 1D

A laminate was produced in the same manner as in example 1D, except for the following matters. That is, in this example, no protective layer is provided. In this example, instead of using a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211℃as the base layer, a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 160℃was used. Further, in this example, instead of using a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211℃as the intermediate layer, a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 160℃was used.

(4.2) Measurement and evaluation method

In addition, the laminate was evaluated for sealability, heat resistance, print visibility, and recycling properties. The puncture strength of the laminate was measured. The method for measuring the probe drop temperature and puncture strength, the method for evaluating sealability, heat resistance, printing visibility, and recycling property are described below.

(4.2.1) Method for measuring the temperature at which the probe falls

The probe-down temperature was evaluated by the method described in (1.2.1).

(4.2.2) Method for evaluating sealability

The sample obtained by cutting the laminate into 10cm square was folded in half so that the sealant layer was inside, and heat-sealed using a heat sealer. Specifically, the lower surface sealing temperature was set at 100℃and the upper surface sealing temperature was set at 120℃at the same time, and a pressure of 0.1MPa was applied for 1 second. Further, the upper surface of the folded sample was observed for the area contacting the heat sealing bar while confirming the presence or absence of melting of the sealing surface. When the upper surface of the sample was not melted or had a poor appearance, the upper surface sealing temperature was increased every 10 ℃ while the lower surface sealing temperature was fixed at 100 ℃ until the upper surface of the sample was melted or had a poor appearance, and the same pressurization and observation as described above were performed. Further, the temperature at which the upper surface of the sample was melted or the appearance was poor was recorded. The sealability was evaluated using the following criteria.

(4.2.3) Evaluation method of printing visibility

The printing visibility was evaluated by the method described in (1.2.3).

(4.2.4) Method for evaluating cycle regenerability

The proportion of polyethylene in the total amount of resin contained in the laminate was calculated. The recycling property was evaluated by referring to the following ratio.

A: the proportion of polyethylene is 90 mass% or more.

B: the proportion of polyethylene is less than 90 mass%.

(4.2.5) Method for measuring puncture Strength

Puncture strength was evaluated by the method described in (3.2.5).

(4.2.6) Method for evaluating Heat resistance

The heat resistance was evaluated by the method described in (2.2.4).

(4.3) Results

The measurement and evaluation results are shown in table 4 below.

As shown in table 4, the laminate having the probe lowering temperature of 180 ℃ or higher was excellent in both heat resistance and printing visibility. Furthermore, the probe lowering temperature of the base material layer was 180 ℃ or higher, and the sealing properties of the laminate having the protective layer were also excellent. In addition, the laminate having the probe lower temperature of 180 ℃ or higher and the protective layer both of the base material layer and the intermediate layer exhibited high puncture strength. And the heat resistance and visibility of the laminate in which the probe lowering temperature of the base material layer is less than 180℃are insufficient. In addition, the laminate having both the base material layer and the intermediate layer with a probe-down temperature of less than 180 ℃ exhibited low puncture strength.

(5) Test E

(5.1) Production of laminate

(5.1.1) Example 1E

The laminate 10E2 shown in fig. 10 was produced by the following method. In this example, a print layer is provided between the base material layer 1 and the first adhesive layer 3A.

First, a polyethylene film having a thickness of 25 μm and subjected to corona treatment on one surface was prepared as a base layer. The polyethylene film had a density of 0.950g/cm ³ and a probe-dropping temperature of 211 ℃. As will be described later, in this example and the examples and comparative examples described below, the probe-down temperature was measured by the method described in (1.2.1). The corona-treated surface of the base material layer was printed with a pattern using gravure ink to form a printed layer.

Further, as an intermediate layer, a polyethylene film having a thickness of 40 μm and subjected to corona treatment on one surface was prepared. The polyethylene film had a density of 0.949g/cm ³ and a probe-drop temperature of 156 ℃. A silicon oxide (SiO _x) vapor-deposited film was formed on the corona-treated surface of the intermediate layer by using a vacuum vapor deposition device of electron beam heating system as an inorganic compound layer to a thickness of 10 nm.

Next, a dry lamination adhesive (urethane adhesive) was applied to the surface of the substrate layer on which the print layer was formed and the back surface of the intermediate layer on which the inorganic compound layer was formed, and the coating film was dried to form first and second adhesive layers each having a thickness of 3 μm. Further, the base material layer and the intermediate layer were bonded with the first adhesive layer interposed therebetween and the printed layer and the inorganic compound layer facing each other, and the intermediate layer was bonded to a linear low density polyethylene resin (LLDPE) film (thickness: 60 μm) as a sealant layer via the second adhesive layer.

A laminate was produced as described above.

(5.1.2) Example 2E

A laminate 10E1 shown in fig. 9 was produced in the same manner as in example 1EC, except that the inorganic compound layer was not provided. In this example, a print layer was also provided between the base material layer 1 and the first adhesive layer 3A, as in example 1E.

(5.1.3) Example 3E

A laminate 10E2 shown in fig. 10 was produced in the same manner as in example 1E, except that a polyamine-based gas barrier adhesive was used as the adhesive instead of using a dry lamination adhesive (urethane-based adhesive). In this example, a print layer was also provided between the base material layer 1 and the first adhesive layer 3A, as in example 1E.

(5.1.4) Example 4E

The laminate 10E2 shown in fig. 10 was produced in the same manner as in example 1E, except for the following matters. That is, in this example, instead of using the polyethylene film having a probe lowering temperature of 211℃as the base material layer, a polyethylene film having a thickness of 25 μm, a density of 0.950g/cm ³, a probe lowering temperature of 205℃and corona-treated on one surface was used. Further, in this example, instead of using the polyethylene film having a probe lowering temperature of 156℃as the intermediate layer, a polyethylene film having a thickness of 25 μm, a density of 0.950g/cm ³, a probe lowering temperature of 160℃and corona-treated on one surface was used. In this example, a print layer was also provided between the base material layer 1 and the first adhesive layer 3A, as in example 1E.

(5.1.5) Example 5E

A laminate 10E2 shown in fig. 10 was produced in the same manner as in example 1E, except that the following polyethylene film was used as the base material layer instead of using the polyethylene film having a probe lowering temperature of 211 ℃. That is, in this example, a polyethylene film having a thickness of 25 μm, a density of 0.950g/cm ³, a probe-lowering temperature of 203℃and corona-treated on one surface was used as the base layer. In this example, a print layer was also provided between the base material layer 1 and the first adhesive layer 3A, as in example 1E.

(5.1.6) Example 6E

The laminate 10C2 shown in fig. 6 was produced in the same manner as in example 1E, except for the following matters. That is, in this example, instead of using the polyethylene film having the probe lowering temperature of 156℃as the intermediate layer, a polyethylene film having a thickness of 25 μm, a density of 0.950g/cm ³, a probe lowering temperature of 211℃and corona-treated on one surface was used. In this example, a print layer was also provided between the base material layer 1 and the first adhesive layer 3A, as in example 1E.

(5.1.7) Comparative example 1E

A laminate was produced in the same manner as in example 1E, except that a polyethylene film having a thickness of 40 μm, a density of 0.949g/cm ³, a probe-lowering temperature of 156 ℃ and a corona treatment on one surface was used as the base layer instead of using the above polyethylene film having a probe-lowering temperature of 211 ℃.

(5.1.8) Comparative example 2E

A laminate was produced in the same manner as in example 1E, except for the following matters. That is, in this example, instead of using the polyethylene film having a probe lowering temperature of 211℃as the base material layer, a polyethylene film having a thickness of 40 μm, a density of 0.949g/cm ³, a probe lowering temperature of 156℃and corona-treated on one surface was used. In this example, instead of using the polyethylene film having a probe lowering temperature of 156℃as the intermediate layer, a polyethylene film having a thickness of 25 μm, a density of 0.950g/cm ³, a probe lowering temperature of 205℃and corona-treated on one surface was used.

(5.2) Measurement and evaluation method

The laminate was evaluated for sealability, heat resistance, print visibility, and gas barrier property. The laminate was subjected to drop strength measurement. The method for measuring the probe drop temperature and drop strength, the method for evaluating sealability, heat resistance, print visibility, and gas barrier property are described below.

(5.2.1) Method for measuring the temperature at which the probe decreases

The probe-down temperature was evaluated by the method described in (1.2.1).

(5.2.2) Method for evaluating sealability

The sealability was evaluated by the method described in (3.2.2).

(5.2.3) Evaluation method of printing visibility

The printing visibility was evaluated by the method described in (1.2.3).

(5.2.4) Method for evaluating gas Barrier Properties

The gas barrier properties were evaluated by the method described in (1.2.4).

(5.2.5) Method for measuring drop Strength

The laminate was cut to a predetermined size, and the peripheral portion was heat-sealed to prepare 10 bags. These bags are provided with openings for placing contents therein. The dimensions of the bag were 100mm by 150mm. Next, 200mL of tap water was filled in each bag, and the opening was heat-sealed to obtain a packaged article. Then, each packaged article was stored at 5 ℃ for 1 day, and then dropped 50 times from a height of 1.5 m. The ratio of the number of packaged articles in which the bag ruptured within 50 times to the total number of packaged articles (10) was calculated as the drop strength.

(5.2.6) Method for evaluating Heat resistance

The heat resistance was evaluated by the method described in (1.2.5).

(5.3) Results

The measurement and evaluation results are shown in table 5 below.

As shown in table 5, the laminate having the probe lowering temperature of 180 ℃ or higher in the base layer was excellent in sealability, heat resistance and printing visibility. Further, the laminate having the probe-lowering temperature of the base material layer of 180 ℃ or higher and the probe-lowering temperature of the intermediate layer of less than 180 ℃ is excellent in drop strength. The laminate having the substrate layer reduced in temperature below 180℃by the probe is insufficient in sealability, heat resistance and visibility. In addition, the laminate having the probe-lowering temperature of 180 ℃ or higher in the intermediate layer shows low drop strength.

(6) Test F

(6.1) Production of laminate

(6.1.1) Example 1F

The laminate 10F1 shown in fig. 12 was produced by the following method.

Further, a polyethylene film having a thickness of 25 μm and a probe-dropping temperature of 160℃was prepared as an intermediate layer. Then, corona treatment is applied to one surface of the intermediate layer. A silicon oxide (SiO _x) vapor-deposited film was formed as an inorganic compound layer to a thickness of 40nm using a vacuum vapor deposition apparatus of electron beam heating type on the corona-treated surface of the intermediate layer. Then, a coating liquid for forming a coating layer was applied to the inorganic compound layer to form a coating layer having a thickness of 0.3 μm and formed of an organic-inorganic mixture.

A laminate was produced as described above.

(6.1.2) Example 2F

A laminate 10F1 shown in fig. 12 was produced in the same manner as in example 1F, except that the thickness of the protective layer was 1 μm.

(6.1.3) Example 3F

A laminate 10F1 shown in fig. 12 was produced in the same manner as in example 1F, except that the thickness of the protective layer was 3 μm.

(6.1.4) Example 4F

A laminate was produced in the same manner as in example 1F, except that no protective layer was provided, and instead of using a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 106 c, a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211 c was used as the intermediate layer.

(6.1.5) Comparative example 1F

A laminate was produced in the same manner as in example 1F, except for the following matters. That is, in this example, no protective layer is provided. In this example, instead of using a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211℃as the base layer, a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 160℃was used. Further, in this example, instead of using a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 160℃as the intermediate layer, a polyethylene film having a thickness of 25 μm and a probe-lowering temperature of 211℃was used.

(6.2) Measurement and evaluation method

In addition, the laminate was evaluated for sealability, heat resistance, print visibility, and recycling properties. The laminate was subjected to drop strength measurement. The method for measuring the probe drop temperature and drop strength, the method for evaluating sealability, heat resistance, printing visibility, and recycling property are described below.

(6.2.1) Method for measuring the temperature at which the probe falls

The probe-down temperature was evaluated by the method described in (1.2.1).

(6.2.2) Method for evaluating sealability

The sealability was evaluated by the method described in (4.2.2).

(6.2.3) Evaluation method of printing visibility

The printing visibility was evaluated by the method described in (1.2.3). (6.2.4) evaluation method of recycling reproducibility was evaluated by the method described in (4.2.4). (6.2.5) method for measuring drop Strength

Drop strength was evaluated by the method described in (5.2.5). (6.2.6) method for evaluating Heat resistance

The heat resistance was evaluated by the method described in (2.2.4).

(6.3) Results

The results of the measurement and evaluation are shown in table 6 below.

As shown in table 6, the laminate having the probe lowering temperature of 180 ℃ or higher was excellent in both heat resistance and printing visibility. The probe-lowering temperature of the base material layer was 180 ℃ or higher, and the sealing properties of the laminate having the protective layer were also excellent. The laminate having the substrate layer with a probe-lowering temperature of 180 ℃ or higher and the intermediate layer with a probe-lowering temperature of less than 180 ℃ has excellent drop strength. The laminate having the substrate layer reduced in temperature below 180℃by the probe is insufficient in sealability, heat resistance and visibility. In addition, the laminate having the probe-lowering temperature of 180 ℃ or higher in the intermediate layer shows low drop strength.

Symbol description

A base material layer, A2 sealant layer, a3 adhesive layer, a 3A first adhesive layer, a 3B second adhesive layer, a 4 print layer, a 5 inorganic compound layer, a 6 protective layer, a7 cover layer, an 8 intermediate layer, a 10A1 laminate, a 10A2 laminate, a 10B1 laminate, a 10B2 laminate, a 10C1 laminate, a 10C2 laminate, a 10C3 laminate, a 10D1 laminate, a 10E2 laminate, a 10E3 laminate, a 10F1 laminate, a 100A packaged article, a 100B packaged article, a 100C packaged article, a 110A packaged article, a 110B packaged article, a 110C1 container body, a 110C2 mouth member, and a 110C3 lid.

Claims

1. A laminate comprising a base layer, an adhesive layer, and a sealant layer in this order,

The substrate layer and the sealant layer comprise polyethylene,

The probe lowering temperature of the substrate layer is 180 ℃ or higher.

2. The laminate according to claim 1, wherein the probe-lowering temperature of the base material layer is 220 ℃ or lower.

3. The laminate according to claim 1 or 2, further comprising an intermediate layer which is present between the base material layer and the sealant layer and which comprises polyethylene.

4. A laminate according to claim 3, wherein the probe-lowering temperature of the intermediate layer is 180 ℃ or less.

5. The laminate according to claim 4, wherein the probe-lowering temperature of the intermediate layer is 140 ℃ or higher.

6. The laminate according to claim 3, wherein the probe-lowering temperature of the intermediate layer is 180 ℃ or higher.

7. The laminate according to claim 6, wherein the probe-lowering temperature of the intermediate layer is 220 ℃ or lower.

8. The laminate according to any one of claims 1 to 7, further comprising a protective layer which is an outermost layer facing the sealant layer with the base material layer interposed therebetween.

9. The laminate according to claim 8, wherein the protective layer is formed of a thermosetting resin.

10. The laminate according to any one of claims 1 to 9, wherein the substrate layer is a biaxially stretched film.

11. The laminate according to any one of claims 1 to 9, wherein the substrate layer is a uniaxially stretched film.

12. The laminate according to any one of claims 1 to 11, further comprising a gas barrier layer that is present between the base material layer and the sealant layer.

13. The laminate according to any one of claims 1 to 12, wherein the adhesive layer is gas barrier.

14. The laminate according to any one of claims 1 to 13, wherein the sealant layer is white.

15. The laminate according to any one of claims 1 to 14, wherein the proportion of polyethylene is 90 mass% or more.

16. A package comprising the laminate of any one of claims 1 to 15.

17. The package of claim 16, which is a stand-up pouch.

18. A packaged article comprising the package of claim 16 or 17 and contents contained therein.