Oxygen-absorbing sealant film

Abstract

To provide an oxygen-absorbing sealant film that can obtain good heat seal strength while maintaining an oxygen absorption rate of an oxygen absorber containing iron powder.SOLUTION: As shown in Fig.1, there is provided an oxygen-absorbing sealant film 10 including at least a first skin layer 12, an oxygen absorbing layer 14, and a second skin layer 16 in this order, which are fused together, in which the oxygen absorbing layer 14 contains iron powder and a polyolefin resin, the first skin layer 12 contains a polyethylene resin, and a thickness of the first skin layer 12 is more than 10 μm, and the oxygen-absorbing sealant film 10 is an inflation film.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an oxygen-absorbing sealant film. [Background technology]

[0002] Many techniques have been proposed for imparting oxygen absorbing properties to packaging materials themselves using oxygen absorbing resin compositions in which oxygen scavengers are dispersed in polyolefin resins. Various inorganic and organic oxygen scavengers are known, but from the viewpoints of oxygen absorbing performance, thermal stability to withstand high temperatures during processing, economy, and hygiene, those made of iron powder and an oxidation promoter are preferably used. These iron-based oxygen scavengers are generally in the form of granules or powder.

[0003] As a method for producing an oxygen-absorbing laminate film containing an iron-based oxygen scavenger, known methods such as a co-extrusion lamination method in which the oxygen-absorbing resin composition constituting the oxygen-absorbing layer and the resin layers constituting the other layers are simultaneously heated and melted and laminated, an extrusion lamination method in which only the oxygen-absorbing resin composition is heated and melted and laminated with the resin films constituting the other layers, and a dry lamination method in which a single-layer oxygen-absorbing layer film is formed in advance and then bonded to the films constituting the other layers using an adhesive are applied.

[0004] As a method for producing such an oxygen-absorbing laminate film, Patent Document 1 discloses a method for producing an oxygen-absorbing laminate film consisting of, from at least the outside, an oxygen barrier layer A / an intermediate layer B / an adhesion strengthening layer C / an oxygen absorbing layer D containing an iron-based oxygen scavenger / a sealant layer E, in which the adhesion strengthening layer C, an oxygen absorbing layer D containing an iron-based oxygen scavenger or the adhesion strengthening layer C, an oxygen absorbing layer D containing an iron-based oxygen scavenger, and a sealant layer E are co-extrusion laminated on the surface of the intermediate layer B. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-260285 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides an oxygen-absorbing sealant film that can obtain good heat seal strength while maintaining the oxygen absorption rate of an oxygen absorber containing iron powder. [Means for solving the problem]

[0007] As a result of intensive research, the present inventors have found that the above problems can be solved by the following means, and have completed the present invention. That is, the present invention is as follows: <Embodiment 1> An oxygen-absorbing sealant film having at least a first skin layer, an oxygen-absorbing layer, and a second skin layer in this order, which are fused to each other, The oxygen absorbing layer contains iron powder and a polyolefin resin, The first skin layer contains a polyethylene resin; and The thickness of the first skin layer is greater than 10 μm; The oxygen absorbing sealant film is an inflation film. Oxygen absorbing sealant film. <Aspect 2> The oxygen-absorbing sealant film according to aspect 1, wherein the oxygen-absorbing layer has a thickness of 5 μm or more and less than 30 μm. <Aspect 3> The oxygen absorbing sealant film according to aspect 1 or 2, wherein the content of the iron powder is 40 mass% or more relative to the mass of the oxygen absorbing layer. <Aspect 4> The oxygen-absorbing sealant film according to aspect 1 or 2, wherein the thickness of the second skin layer is greater than 10 μm and less than 50 μm. <Aspect 5> The oxygen-absorbing sealant film described in aspect 1 or 2, wherein the polyethylene resin of the first skin layer is a linear low-density polyethylene. <Aspect 6> The density of the first skin layer is 0.930 g / cm 3 6. The oxygen absorbing sealant film of embodiment 5, wherein: Aspect 7: A packaging laminate, The oxygen-absorbing sealant film according to aspect 1 or 2 has a base layer, The substrate layer is laminated on the surface of the first skin layer of the oxygen absorbing sealant film opposite to the oxygen absorbing layer. Packaging laminates. <Aspect 8> A packaging container having the packaging laminate of Aspect 7. <Aspect 9> A packaging container containing contents, the contents being contained in the packaging container described in aspect 8. Effect of the Invention

[0008] According to the present invention, it is possible to provide an oxygen-absorbing sealant film that can obtain good heat seal strength while maintaining the oxygen absorption rate of an oxygen absorber containing iron powder. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a side cross-sectional view of the oxygen-absorbing sealant film of the present invention. [Diagram 2] FIG. 2 is a side cross-sectional view of the packaging laminate of the present invention. [Diagram 3] Fig. 3(a) is a front view of a laminate for evaluation of heat seal strength, and Fig. 3(b) is a side cross-sectional view taken along line bb in Fig. 3(a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Oxygen-absorbing sealant film> As shown in FIG. 1, the oxygen absorbing sealant film 10 of the present invention has at least a first skin layer 12, an oxygen absorbing layer 14, and a second skin layer 16 in this order, which are fused together. The oxygen absorbing layer 14 contains iron powder and a polyolefin resin, The first skin layer 12 contains a polyethylene resin, and The thickness of the first skin layer 12 is greater than 10 μm; The oxygen-absorbing sealant film 10 is an inflation film.

[0011] The present inventors have found that the above-mentioned configuration, particularly the thickness of the first skin layer being more than 10 μm and the film being an inflation film, provides good heat sealability. Without wishing to be bound by theory, this is believed to be because the resin composition constituting the first skin layer, the oxygen absorbing layer, and the second skin layer is immediately cooled when extruded from the ring-shaped die of the inflation molding machine, and because the oxygen absorbing layer is supported on the back side by the first skin layer during heat sealing, stress is alleviated, thereby making it possible to prevent the iron powder from being exposed to the surface.

[0012] In general, iron powder has a large particle size, and in the past, when an oxygen-absorbing sealant film was obtained using a resin composition (master batch) containing iron powder, the film did not have sufficient strength, and it was not possible to form the film, or even if it was possible to form the film, the heat seal strength was reduced. On the other hand, when the master batch was diluted with a resin to suppress the reduction in heat seal strength, a sufficient oxygen absorption rate was not obtained in some cases, but the configuration of the present invention can solve this problem.

[0013] The oxygen absorbing sealant film of the present invention can be produced by simultaneously forming and laminating the first skin layer, the oxygen absorbing layer and the second skin layer by a multi-layer inflation method.

[0014] Each component of the present invention will now be described.

[0015] The first skin layer The first skin layer contains a polyethylene resin and has a thickness of more than 10 μm. The first skin layer may be laminated on one side of the oxygen absorbing layer. The first skin layer is fused to the oxygen absorbing layer. The first skin layer can be a layer that is bonded to the base layer in the packaging laminate described below.

[0016] The thickness of the first skin layer may be greater than 10 μm and less than or equal to 100 μm. The thickness may be greater than 10 μm, greater than or equal to 12 μm, or greater than or equal to 15 μm, and may be less than or equal to 100 μm, less than or equal to 90 μm, less than or equal to 80 μm, less than or equal to 70 μm, less than or equal to 60 μm, less than or equal to 50 μm, less than or equal to 50 μm, less than or equal to 45 μm, less than or equal to 40 μm, less than or equal to 35 μm, less than or equal to 30 μm, less than or equal to 25 μm, or less than or equal to 23 μm.

[0017] (Polyethylene resin) In the present invention, and in this specification, a polyethylene-based resin is a resin that contains more than 50 mol%, 60 mol% or more, 70 mol% or more, or 80 mol% or more of ethylene group repeating units in the main chain of the polymer, and is, for example, selected from the group consisting of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-vinyl acetate copolymer (EVA), carboxylic acid-modified polyethylene, carboxylic acid-modified ethylene-vinyl acetate copolymer, ionomer, and derivatives thereof, and mixtures thereof.

[0018] The density of polyethylene resin is 0.900g / cm 3 More than 0.905g / cm 3 More than 0.910g / cm 3 More than 0.915g / cm 3 or more than 0.920g / cm 3 or more, and may be 0.950 g / cm 3 Below, 0.945g / cm 3Below, 0.940g / cm 3 Below, 0.935g / cm 3 or less than 0.930g / cm 3 In particular, the density may be 0.930 g / cm 3 From the viewpoint of heat seal strength, it is preferable that the above-mentioned value is not more than 1.0.

[0019] <Oxygen Absorption Layer> The oxygen absorbing layer contains iron powder and a polyolefin resin, and is fused to the first and second skin layers.

[0020] The thickness of the oxygen absorbing layer may be 5 to 100 μm. This thickness may be 5 μm or more, 7 μm or more, 10 μm or more, 12 μm or more, or 15 μm or more, and may be 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 33 μm or less, 30 μm or less, less than 30 μm, 25 μm or less, 20 μm or less, or 18 μm or less. Among these, it is preferable that the thickness of the oxygen absorbing layer is less than 30 μm from the viewpoint of obtaining good heat seal strength.

[0021] The content of iron powder in the oxygen absorbing layer may be 30 to 80% by mass relative to the mass of the oxygen absorbing layer. This content may be 30% by mass or more, 33% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more, 48% by mass or more, or 50% by mass or more, and may be 80% by mass or less, 75% by mass or less, 70% by mass or less, or 65% by mass or less. In particular, the oxygen absorbing sealant film of the present invention is useful because it can obtain good heat sealability even when the content of iron powder is 40% by mass or more.

[0022] The oxygen absorbing layer may further contain an oxidation promoter. In this case, the content of the oxidation promoter may be 1 to 30% by mass relative to the mass of the iron powder. This content may be 1% by mass or more, 3% by mass or more, 5% by mass or more, 7% by mass or more, or 10% by mass or more, and may be 30% by mass or less, 25% by mass or less, 20% by mass or less, or 15% by mass or less, relative to the mass of the iron powder.

[0023] The oxygen absorbing layer may further contain an oxygen absorbent other than the iron powder. In this case, the content of the other oxygen absorbent may be 10% by mass or less, 7% by mass or less, 5% by mass or less, 3% by mass or less, 1% by mass or less, or 0% by mass, based on the mass of the oxygen absorbing layer.

[0024] (Iron powder) The iron powder that can be used includes, for example, reduced iron powder, atomized iron powder, activated iron powder, etc. As such iron powder, commercially available master batches can be used.

[0025] (Polyolefin resin) As the polyolefin resin, for example, a polyethylene resin, a polypropylene resin, or the like can be used.

[0026] As the polyethylene-based resin, the polyethylene-based resins listed for the first skin layer can be used.

[0027] In this specification, a polypropylene-based resin refers to a resin containing more than 50 mol%, 60 mol% or more, 70 mol% or more, or 80 mol% or more of propylene group repeating units in the main chain of the polymer, and examples thereof include polypropylene (PP) homopolymer, random polypropylene (random PP), block polypropylene (block PP), chlorinated polypropylene, acid-modified polypropylene, derivatives thereof, and mixtures thereof.

[0028] (Pro-oxidant) As the oxidation promoter, an alkali metal chloride such as sodium chloride, an alkaline earth metal oxide such as calcium chloride or magnesium chloride, or the like can be used.

[0029] (Other oxygen absorbers) As oxygen absorbents other than iron powder, iron compounds such as ferrous oxide and ferrous salts, metal halides such as calcium chloride and magnesium chloride, and metal oxides such as cerium oxide can be used.

[0030] Second Skin Layer The second skin layer is a skin layer fused to the surface of the oxygen absorbing layer opposite to the first skin layer. For example, a polyolefin resin can be used as the second skin layer. The second skin layer can be a layer for use as a sealant layer. That is, it can be the outermost layer, particularly in the packaging laminate mentioned below.

[0031] The resin that makes up the second skin layer may be different from or the same as the resin that makes up the first skin layer.

[0032] When the second skin layer is made of a polyethylene-based resin, the density of the second skin layer can be determined by referring to the description of the first skin layer.

[0033] The thickness of the second skin layer can be referred to the thickness of the first skin layer. The thickness of the second skin layer may be different from or the same as the thickness of the first skin layer, but is preferably more than 10 μm in terms of heat seal strength, and is preferably less than 50 μm in terms of increasing the oxygen absorption rate and improving the ease of opening when used as a package.

[0034] <<Packaging laminate>> The packaging laminate 20 of the present invention is The oxygen-absorbing sealant film 10 and the base layer 22 are provided. The base layer 22 is laminated to the surface of the first skin layer 12 of the oxygen absorbing sealant film 10 opposite the oxygen absorbing layer 14 .

[0035] The substrate layer 22 and the first skin layer 12 may be bonded to each other, for example, via an adhesive layer 24. Although not shown, the packaging laminate of the present invention may further include a hard substrate layer, particularly a hard resin substrate layer.

[0036] The packaging laminate of the present invention may be, for example, a laminate for a packaging bag, a laminate for a laminate tube, a laminate for a lid material, or a laminate for a packaging container.

[0037] In particular, when the packaging laminate of the present invention is a laminate for a laminate tube, it is preferable from the viewpoint of obtaining a laminate tube that the laminate has another sealant layer on the side opposite to the second skin layer. As the other sealant layer, the resin constituting the second skin layer can be used.

[0038] When the packaging laminate of the present invention is a laminate for a lid material, the second skin layer may be easy-peelable or may be strongly adhesive, i.e., a sealant layer for opening by means other than peeling from the container, such as by cutting; when the second skin layer is particularly strongly adhesive, the packaging laminate of the present invention is useful.

[0039] The form of the packaging container laminate is not particularly limited, and may be, for example, a blister container laminate. In particular, when the packaging container laminate of the present invention is a blister container laminate, it is preferable that the packaging laminate further has a reinforcing layer.

[0040] <Base material layer> The substrate layer may be composed of at least one of a soft substrate layer and a hard substrate layer. The substrate layer may further include a barrier layer. The soft substrate layer, the hard substrate layer, and the barrier layer may each be present in one or more layers, and these layers may be laminated via an adhesive layer.

[0041] A printed layer may be laminated on at least a part of the above-mentioned layers constituting the base layer. This printed layer may be printed by gravure printing, flexographic printing, or the like.

[0042] (Soft base material layer) The soft substrate layer means a substrate layer having a flexible property, particularly a substrate layer having a thickness of 100 μm or less. The thickness of the soft substrate layer is not particularly limited as long as it does not impair the flexible property, and may be, for example, 7 μm or more and 100 μm or less. This thickness may be 7 μm or more, or 10 μm or more, or 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 55 μm or less, 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, or 15 μm or less.

[0043] As such a substrate layer, a soft resin substrate layer, a soft paper substrate layer, or the like can be used.

[0044] (Soft base material layer: Soft resin base material layer) The soft resin substrate layer may be composed of a thermoplastic resin having excellent impact resistance, abrasion resistance, etc., such as a vinyl resin, a polyester resin, a polyamide resin, etc. The soft resin substrate layer may be a single layer or a laminate.

[0045] Examples of vinyl resins include polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polychlorotrifluoroethylene, polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polytetrafluoroethylene, polyacrylonitrile (PAN), and the like.

[0046] Examples of polyester resins include polyethylene terephthalate (PET) and polybutylene terephthalate.

[0047] Examples of polyamide resins include nylons such as Nylon (registered trademark) 6 and Nylon MXD6.

[0048] As the laminate for the soft resin substrate layer, a laminate of PVF / PET / PVF, for example, a known laminate called TPT, can be used.

[0049] From the viewpoint of the mechanical strength of the packaging laminate, the thickness of the soft resin substrate layer is preferably 7 μm or more, or 10 μm or more, and may be 55 μm or less, 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, or 15 μm or less.

[0050] The resin constituting the soft resin substrate layer may be one type or a blend of two or more types, and additives for imparting functionality, etc. may be blended as necessary.

[0051] The soft resin substrate layer is preferably made of a preformed film. The film to be the soft resin substrate layer may be a film formed from the above-mentioned resin or the like, and may be unstretched or uniaxially or biaxially stretched. Among them, a biaxially stretched film is preferable.

[0052] (Soft base layer: Soft paper base layer) As the soft paper base layer, coated paper, art paper, etc. may be used.

[0053] The basis weight of the paper that constitutes the soft paper base layer is 10 g / m 2 More than 30g / m 2 or more than 50g / m 2 or more, and may be 200 g / m 2 Below 150g / m 2 or less than 100g / m 2 It may be the following:

[0054] (Hard base material layer) The hard substrate layer means a substrate layer having a hard property, particularly a substrate layer having a thickness of more than 100 μm. The thickness of the hard substrate layer is not particularly limited as long as it does not impair the hard property, and may be, for example, more than 100 μm and 3 mm or less. This thickness may be more than 100 μm, 150 μm or more, 200 μm or more, 250 μm or more, or 300 μm or more, and may be 3 mm or less, 2 mm or less, 1 mm or less, 900 μm or less, 800 μm or less, 700 μm or less, 600 μm or less, or 500 μm or less.

[0055] As the hard substrate layer, for example, a hard resin substrate layer, a hard paper substrate layer, or a hard inorganic substrate layer can be used.

[0056] (Hard base material layer: hard resin base material layer) As the hard resin substrate layer, for example, a polyvinyl chloride layer, a polycarbonate layer, a polypropylene layer, or the like can be used.

[0057] (Hard base layer: hard paper base layer) As the hard paper substrate layer, for example, paperboard, corrugated cardboard, etc. can be used.

[0058] (Hard base material layer: hard inorganic base material layer) As the hard inorganic substrate layer, for example, a glass layer or the like can be used.

[0059] (Barrier layer) The barrier layer may be made of a material capable of preventing moisture, organic gases, inorganic gases, etc. from passing from the base layer side to the second skin layer side and / or preventing oxygen from passing from the outside, thereby preventing the oxygen absorbing layer from being deactivated. Examples of such a barrier layer include a simple metal foil layer such as copper foil or aluminum foil, an alloy foil layer such as stainless steel foil, an inorganic vapor deposition film such as a silica vapor deposition film, an alumina vapor deposition film, an aluminum vapor deposition film, or a silica-alumina binary vapor deposition film, a barrier resin layer such as an ethylene-vinyl alcohol copolymer (EVOH), a cyclic olefin polymer (COP), or a cyclic olefin copolymer (COC), or an organic coating film such as a polyvinylidene chloride coating film, a polychlorotrifluoroethylene coating film, or a polyvinylidene fluoride coating film.

[0060] In particular, among the above barrier layers, the inorganic vapor deposition film, the barrier resin layer and the organic coating film can act as a transparent barrier layer.

[0061] When an inorganic vapor deposition film or an organic coating film is used as the barrier layer, the thickness of the barrier layer is preferably 100 nm or more, 200 nm or more, 300 nm or more, 500 nm or more, 700 nm or more, or 1 μm or more from the viewpoint of ensuring strength and barrier properties, and is preferably 5 μm or less, 4 μm or less, 3 μm or less, or 2 μm or less from the viewpoint of reducing the thickness of the entire packaging laminate.

[0062] When a metal foil layer or a barrier resin layer is used as the barrier layer, the thickness of the barrier layer is preferably 5 μm or more, or 7 μm or more, from the viewpoint of ensuring strength and barrier properties, and is preferably 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, 15 μm or less, or 10 μm or less, from the viewpoint of reducing the thickness of the entire packaging laminate.

[0063] (Adhesive layer) As the adhesive layer, for example, a dry lamination adhesive, a hot lamination adhesive, or the like can be used.

[0064] Other Layers The packaging laminate of the present invention may optionally have other layers, such as an adhesive layer between the substrate layer and the first skin layer, and an anchor coat layer.

[0065] 《Packaging container》 The packaging container of the present invention has the above-mentioned packaging laminate.

[0066] The packaging container of the present invention may be a content-containing packaging container having contents accommodated in the packaging container.

[0067] The packaging container of the present invention may be a packaging bag, a laminated tube, or a container with a lid.

[0068] In particular, the packaging bag of the present invention comprises one or more of the above-mentioned packaging laminates, A part of one or more sheets of the packaging laminate is heat-sealed to another part of the packaging laminate or to another film to form a bag, where the other film may be another packaging laminate or may be a film other than the packaging laminate.

[0069] Here, one embodiment of the packaging bag of the present invention may be a bag having at least a peripheral seal portion in which two films are heat-sealed facing each other at their peripheral edges. The peripheral seal portion can be obtained by a method including placing two films facing each other and heat-sealing at least a part of the peripheral edges of these films. Examples of such packaging bags include standing pouches, retort pouches, spout pouches, and four-sided sealed bags.

[0070] One embodiment of the packaging bag of the present invention may be a bag having at least a back seal portion in which both opposing ends of a single film are heat-sealed. This back seal portion can be obtained by a method including overlapping sealant layers at both opposing ends of a single film and heat-sealing them to form a cylindrical shape. Examples of such packaging bags include three-sided sealed bags, gusset bags, and pillow bags.

[0071] The packaging bag of the present invention may also be a bag-in-box, that is, an inner container that constitutes a container that combines a soft inner container with an outer container that is generally constituted by a cardboard box.

[0072] When the packaging container of the present invention is a container with a lid, the packaging laminate may be either the lid material or the container.

[0073] Furthermore, when the packaging laminate has a paper base material, the packaging container of the present invention may be a paper laminate pack, such as a beverage pack.

[0074] Other films The other film is not particularly limited and may be, for example, a transparent barrier film. The transparent barrier film may have, for example, the transparent barrier layer, the soft resin substrate layer, and the sealant layer. In addition, a printing layer may be applied to at least a part of the transparent barrier film.

[0075] <Contents> The contents may be, for example, food, medicine, electronic components, etc.

[0076] The food may be, for example, liquid foods such as beverages, edible oils, soups, liquid seasonings, etc.; solid foods such as sweets, cooked rice, bread, etc.; semi-solid foods such as jelly, tofu, miso, mayonnaise, jam, cream, paste, etc.; and powders and granules such as powdered soup.

[0077] The medicinal products may be, for example, medicines, toiletries, cosmetics, and the like.

[0078] The pharmaceutical product may be, for example, a solid pharmaceutical product such as a tablet or capsule, a liquid pharmaceutical product such as an infusion, or a semi-solid pharmaceutical product such as a transdermal agent.

[0079] The toiletry product may be, for example, shampoo, rinse, detergent, etc.

[0080] The cosmetic product may be, for example, a milky lotion, a moisturizing lotion, a skin toner, or the like. EXAMPLES

[0081] The present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these.

[0082] <<Preparation of oxygen-absorbing sealant film>> Example 1 Using an inflation molding machine, a two-kind, three-layer oxygen-absorbing sealant film having a 10 μm-thick second skin layer, a 15 μm-thick oxygen-absorbing layer, and a 10 μm-thick first skin layer was obtained by coextrusion inflation.

[0083] The first and second skin layers are made of linear low density polyethylene (LLDPE1, density 0.925 g / cm 3 As the oxygen absorbing layer, a polyethylene master batch containing 50 to 60 mass % of iron powder (iron powder MB) was used.

[0084] A laminate of a polyethylene terephthalate (PET) film (thickness 12 μm) / / alloy aluminum (AL) (thickness 9 μm) / / nylon (Ny) film (thickness 15 μm) as a base layer (" / / " indicates that it is bonded with a dry laminate adhesive) was bonded to the first skin layer side of the obtained oxygen-absorbing sealant film via a two-component dry laminate adhesive to produce the packaging laminate of Example 1.

[0085] Examples 2 to 8 and Comparative Examples 1 to 4 Packaging laminates of Examples 2 to 8 and Comparative Examples 1 to 3 were produced in the same manner as in Example 1, except that the materials constituting each layer were changed as shown in Table 1. The packaging laminate of Comparative Example 4 was produced by adhering the above-mentioned base layer to the oxygen absorbing layer of a commercially available oxygen absorbing sealant film having an oxygen absorbing layer and a skin layer in this order.

[0086] Other materials shown in Table 1 are as follows: LLDPE2: Linear low density polyethylene, density 0.903g / cm 3 LLDPE3: Linear low density polyethylene, density 0.922g / cm 3 LLDPE4: Linear low density polyethylene, density 0.936g / cm 3 LDPE: Low density polyethylene Modified PO: Acid-modified polyolefin

[0087] In addition, in Table 1, the term "T-die" means that an oxygen-absorbing sealant film was obtained by an extrusion lamination method in which an oxygen-absorbing layer was extruded using a T-die molding machine and laminated with a film-like sealant layer.

[0088] "evaluation" <Heat seal strength> 3(a) and (b), the second skin layer 16 of the same packaging laminate 20 was placed facing each other, and heat-sealed under the conditions of upper die temperature 120°C, lower die temperature 120°C, sealing time 0.5 seconds, and sealing pressure 0.2 MPa to obtain an evaluation laminate 400. The heat seal strength was measured by T-peeling in the X direction under the conditions of width 15 mm, chuck distance 50 mm, and tensile speed: 300 mm / min. The peel direction 410A of the sealed portion 410 was 10 mm, and the width 410B perpendicular to the peel direction was 15 mm.

[0089] <Oxygen absorption amount> The packaging laminate is placed in a polyethylene terephthalate / aluminum foil / polyethylene bag, 6.25 cm thick.2 The bag was then heat-sealed into a tetrahedral shape so that the volume (air volume) of the packaging bag was 13 mL, and the bag was then stored at 40° C. After 3 days, the oxygen concentration in the bag containing the packaging laminate was measured, and the difference between this and the oxygen concentration in the atmosphere was used to calculate the oxygen concentration of 1 cm of the packaging laminate. 2 The amount of oxygen absorbed per unit was calculated. Measurements were performed by inserting the measuring needle of a Pack Reader (RO105L, Iijima Electronics Co., Ltd.), a diaphragm-type galvanic cell-type oxygen sensor, into the bag.

[0090] Table 1 shows the configurations and evaluation results of the examples and comparative examples.

[0091] [Table 1]

[0092] From Table 1, it can be seen that the packaging laminate of the embodiment having a first skin layer having a thickness of more than 10 μm and made of a polyethylene-based resin, and having an oxygen-absorbing sealant film which is an inflation film, has good heat seal strength without compromising the oxygen absorption rate. [Explanation of symbols]

[0093] 10. Oxygen-absorbing sealant film 12 First Skin 14 Oxygen absorbing layer 16 Second Skin 20 Packaging laminate 22 Base material layer 24 Adhesive layer 400 Evaluation laminate 410 Seal part 410A Width of the seal in the peeling direction 410B Width of the seal in the direction perpendicular to the peeling direction X Peeling direction

Claims

1. An oxygen-absorbing sealant film having at least a first skin layer, an oxygen-absorbing layer, and a second skin layer in this order, which are fused to each other, The oxygen absorbing layer contains iron powder and a polyolefin resin, The first skin layer contains a polyethylene resin; and The thickness of the first skin layer is greater than 10 μm; The oxygen absorbing sealant film is an inflation film. Oxygen absorbing sealant film.

2. 2. The oxygen absorbing sealant film according to claim 1, wherein the oxygen absorbing layer has a thickness of 5 μm or more and less than 30 μm.

3. 3. The oxygen absorbing sealant film according to claim 1, wherein the content of the iron powder is 40 mass% or more relative to the mass of the oxygen absorbing layer.

4. 3. The oxygen absorbing sealant film according to claim 1 or 2, wherein the thickness of the second skin layer is more than 10 μm and less than 50 μm.

5. 3. The oxygen-absorbing sealant film according to claim 1, wherein the polyethylene resin of the first skin layer is a linear low-density polyethylene.

6. The density of the first skin layer is 0.930 g / cm ３ The oxygen absorbing sealant film according to claim 5, wherein:

7. A packaging laminate comprising: The oxygen absorbing sealant film according to claim 1 or 2, and a substrate layer, The substrate layer is laminated on the surface of the first skin layer of the oxygen absorbing sealant film opposite to the oxygen absorbing layer. Packaging laminates.

8. A packaging container comprising the packaging laminate of claim 7.

9. A packaging container containing a content, the packaging container comprising the content contained in the packaging container according to claim 8.

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